MDGL

SEC source: 0000950170-23-071116 · ownership.xml · nonDerivative · entry 1

Waltermire Robert E. · CIK 0001876996 · Senior VP, Chief Pharma Dev.

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 7,667

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · kind: All shares issued pursuant to the exercise of the options reported herein represent 4,000 shares underlying an overall option award of 35,000 shares. All exercised options had vested. As to the overall option for 35,000 shares, 25% of the shares underlying the option vested on August 2, 2022 and, thereafter, 6.25% of the shares vested, or will vest, on the last day of each successive three-month period, provided the Reporting Person continues in service with the Issuer on each such date.

SEC source: 0001209191-23-058693 · doc4.xml · nonDerivative · entry 16

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 1,774,294

F15 · price: The price reported in Column 4 is a weighted average price. These shares were traded by 667 and Life Sciences in multiple transactions at prices ranging from $224.65 to $225.00, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

F3 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to the Funds. In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F4 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on board of directors of the Issuer (the "Board") and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the restricted stock units (each, an "RSU"). Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

F7 · ownership.nature: Includes beneficial ownership of 2,396 previously issued RSUs payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

F8 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Brothers Life Sciences Capital, L.P. and (ii) Life Sciences, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I held directly by or held for the benefit of Life Sciences, a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital, L.P., a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital (GP), LLC, due to their interest in Life Sciences and Baker Brothers Life Sciences Capital, L.P.'s right to receive an allocation of a portion of the profits from Life Sciences.

SEC source: 0001209191-23-058693 · doc4.xml · nonDerivative · entry 15

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 184,455

F15 · price: The price reported in Column 4 is a weighted average price. These shares were traded by 667 and Life Sciences in multiple transactions at prices ranging from $224.65 to $225.00, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

F2 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Biotech Capital, L.P. and (ii) 667, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I held directly by or held for the benefit of 667, a limited partnership of which the sole general partner is Baker Biotech Capital, L.P., a limited partnership of which the sole general partner is Baker Biotech Capital (GP), LLC, due to their interest in 667 and Baker Biotech Capital, L.P.'s right to receive an allocation of a portion of the profits from 667.

F3 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to the Funds. In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F4 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on board of directors of the Issuer (the "Board") and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the restricted stock units (each, an "RSU"). Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

F7 · ownership.nature: Includes beneficial ownership of 2,396 previously issued RSUs payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

SEC source: 0001209191-23-058693 · doc4.xml · nonDerivative · entry 14

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 1,768,700

F14 · price: The price reported in Column 4 is a weighted average price. These shares were traded by 667 and Life Sciences in multiple transactions at prices ranging from $223.935 to $223.94, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

F3 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to the Funds. In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F4 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on board of directors of the Issuer (the "Board") and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the restricted stock units (each, an "RSU"). Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

F7 · ownership.nature: Includes beneficial ownership of 2,396 previously issued RSUs payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

F8 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Brothers Life Sciences Capital, L.P. and (ii) Life Sciences, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I held directly by or held for the benefit of Life Sciences, a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital, L.P., a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital (GP), LLC, due to their interest in Life Sciences and Baker Brothers Life Sciences Capital, L.P.'s right to receive an allocation of a portion of the profits from Life Sciences.

SEC source: 0001209191-23-058693 · doc4.xml · nonDerivative · entry 13

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 184,009

F14 · price: The price reported in Column 4 is a weighted average price. These shares were traded by 667 and Life Sciences in multiple transactions at prices ranging from $223.935 to $223.94, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

F2 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Biotech Capital, L.P. and (ii) 667, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I held directly by or held for the benefit of 667, a limited partnership of which the sole general partner is Baker Biotech Capital, L.P., a limited partnership of which the sole general partner is Baker Biotech Capital (GP), LLC, due to their interest in 667 and Baker Biotech Capital, L.P.'s right to receive an allocation of a portion of the profits from 667.

F3 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to the Funds. In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F4 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on board of directors of the Issuer (the "Board") and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the restricted stock units (each, an "RSU"). Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

F7 · ownership.nature: Includes beneficial ownership of 2,396 previously issued RSUs payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

SEC source: 0001209191-23-058693 · doc4.xml · nonDerivative · entry 12

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 1,768,337

F13 · price: The price reported in Column 4 is a weighted average price. These shares were traded by 667 and Life Sciences in multiple transactions at prices ranging from $221.94 to $222.92, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

F3 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to the Funds. In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F4 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on board of directors of the Issuer (the "Board") and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the restricted stock units (each, an "RSU"). Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

F7 · ownership.nature: Includes beneficial ownership of 2,396 previously issued RSUs payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

F8 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Brothers Life Sciences Capital, L.P. and (ii) Life Sciences, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I held directly by or held for the benefit of Life Sciences, a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital, L.P., a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital (GP), LLC, due to their interest in Life Sciences and Baker Brothers Life Sciences Capital, L.P.'s right to receive an allocation of a portion of the profits from Life Sciences.

SEC source: 0001209191-23-058693 · doc4.xml · nonDerivative · entry 11

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 183,980

F13 · price: The price reported in Column 4 is a weighted average price. These shares were traded by 667 and Life Sciences in multiple transactions at prices ranging from $221.94 to $222.92, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

F2 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Biotech Capital, L.P. and (ii) 667, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I held directly by or held for the benefit of 667, a limited partnership of which the sole general partner is Baker Biotech Capital, L.P., a limited partnership of which the sole general partner is Baker Biotech Capital (GP), LLC, due to their interest in 667 and Baker Biotech Capital, L.P.'s right to receive an allocation of a portion of the profits from 667.

F3 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to the Funds. In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F4 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on board of directors of the Issuer (the "Board") and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the restricted stock units (each, an "RSU"). Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

F7 · ownership.nature: Includes beneficial ownership of 2,396 previously issued RSUs payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

SEC source: 0001209191-23-058693 · doc4.xml · nonDerivative · entry 10

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 1,759,075

F12 · price: The price reported in Column 4 is a weighted average price. These shares were traded by 667 and Life Sciences in multiple transactions at prices ranging from $221.51 to $221.90, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

F3 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to the Funds. In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F4 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on board of directors of the Issuer (the "Board") and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the restricted stock units (each, an "RSU"). Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

F7 · ownership.nature: Includes beneficial ownership of 2,396 previously issued RSUs payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

F8 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Brothers Life Sciences Capital, L.P. and (ii) Life Sciences, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I held directly by or held for the benefit of Life Sciences, a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital, L.P., a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital (GP), LLC, due to their interest in Life Sciences and Baker Brothers Life Sciences Capital, L.P.'s right to receive an allocation of a portion of the profits from Life Sciences.

SEC source: 0001209191-23-058693 · doc4.xml · nonDerivative · entry 9

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 183,242

F12 · price: The price reported in Column 4 is a weighted average price. These shares were traded by 667 and Life Sciences in multiple transactions at prices ranging from $221.51 to $221.90, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

F2 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Biotech Capital, L.P. and (ii) 667, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I held directly by or held for the benefit of 667, a limited partnership of which the sole general partner is Baker Biotech Capital, L.P., a limited partnership of which the sole general partner is Baker Biotech Capital (GP), LLC, due to their interest in 667 and Baker Biotech Capital, L.P.'s right to receive an allocation of a portion of the profits from 667.

F3 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to the Funds. In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F4 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on board of directors of the Issuer (the "Board") and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the restricted stock units (each, an "RSU"). Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

F7 · ownership.nature: Includes beneficial ownership of 2,396 previously issued RSUs payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

SEC source: 0001209191-23-058693 · doc4.xml · nonDerivative · entry 8

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 1,754,543

F11 · price: The price reported in Column 4 is a weighted average price. These shares were traded by 667 and Life Sciences in multiple transactions at prices ranging from $219.49 to $220.47, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

F3 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to the Funds. In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F4 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on board of directors of the Issuer (the "Board") and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the restricted stock units (each, an "RSU"). Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

F7 · ownership.nature: Includes beneficial ownership of 2,396 previously issued RSUs payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

F8 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Brothers Life Sciences Capital, L.P. and (ii) Life Sciences, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I held directly by or held for the benefit of Life Sciences, a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital, L.P., a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital (GP), LLC, due to their interest in Life Sciences and Baker Brothers Life Sciences Capital, L.P.'s right to receive an allocation of a portion of the profits from Life Sciences.

SEC source: 0001209191-23-058693 · doc4.xml · nonDerivative · entry 7

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 182,881

F11 · price: The price reported in Column 4 is a weighted average price. These shares were traded by 667 and Life Sciences in multiple transactions at prices ranging from $219.49 to $220.47, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

F2 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Biotech Capital, L.P. and (ii) 667, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I held directly by or held for the benefit of 667, a limited partnership of which the sole general partner is Baker Biotech Capital, L.P., a limited partnership of which the sole general partner is Baker Biotech Capital (GP), LLC, due to their interest in 667 and Baker Biotech Capital, L.P.'s right to receive an allocation of a portion of the profits from 667.

F3 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to the Funds. In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F4 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on board of directors of the Issuer (the "Board") and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the restricted stock units (each, an "RSU"). Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

F7 · ownership.nature: Includes beneficial ownership of 2,396 previously issued RSUs payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

SEC source: 0001209191-23-058693 · doc4.xml · nonDerivative · entry 6

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 1,750,025

F10 · price: The price reported in Column 4 is a weighted average price. These shares were traded by 667 and Life Sciences in multiple transactions at prices ranging from $217.92 to $218.89, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

F3 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to the Funds. In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F4 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on board of directors of the Issuer (the "Board") and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the restricted stock units (each, an "RSU"). Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

F7 · ownership.nature: Includes beneficial ownership of 2,396 previously issued RSUs payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

F8 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Brothers Life Sciences Capital, L.P. and (ii) Life Sciences, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I held directly by or held for the benefit of Life Sciences, a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital, L.P., a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital (GP), LLC, due to their interest in Life Sciences and Baker Brothers Life Sciences Capital, L.P.'s right to receive an allocation of a portion of the profits from Life Sciences.

SEC source: 0001209191-23-058693 · doc4.xml · nonDerivative · entry 5

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 182,521

F10 · price: The price reported in Column 4 is a weighted average price. These shares were traded by 667 and Life Sciences in multiple transactions at prices ranging from $217.92 to $218.89, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

F2 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Biotech Capital, L.P. and (ii) 667, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I held directly by or held for the benefit of 667, a limited partnership of which the sole general partner is Baker Biotech Capital, L.P., a limited partnership of which the sole general partner is Baker Biotech Capital (GP), LLC, due to their interest in 667 and Baker Biotech Capital, L.P.'s right to receive an allocation of a portion of the profits from 667.

F3 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to the Funds. In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F4 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on board of directors of the Issuer (the "Board") and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the restricted stock units (each, an "RSU"). Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

F7 · ownership.nature: Includes beneficial ownership of 2,396 previously issued RSUs payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

SEC source: 0001209191-23-058693 · doc4.xml · nonDerivative · entry 4

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 1,720,287

F9 · price: The price reported in Column 4 is a weighted average price. These shares were traded by 667 and Life Sciences in multiple transactions at prices ranging from $216.90 to $217.89, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

F3 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to the Funds. In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F4 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on board of directors of the Issuer (the "Board") and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the restricted stock units (each, an "RSU"). Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

F7 · ownership.nature: Includes beneficial ownership of 2,396 previously issued RSUs payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

F8 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Brothers Life Sciences Capital, L.P. and (ii) Life Sciences, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I held directly by or held for the benefit of Life Sciences, a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital, L.P., a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital (GP), LLC, due to their interest in Life Sciences and Baker Brothers Life Sciences Capital, L.P.'s right to receive an allocation of a portion of the profits from Life Sciences.

SEC source: 0001209191-23-058693 · doc4.xml · nonDerivative · entry 3

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 180,148

F9 · price: The price reported in Column 4 is a weighted average price. These shares were traded by 667 and Life Sciences in multiple transactions at prices ranging from $216.90 to $217.89, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

F2 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Biotech Capital, L.P. and (ii) 667, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I held directly by or held for the benefit of 667, a limited partnership of which the sole general partner is Baker Biotech Capital, L.P., a limited partnership of which the sole general partner is Baker Biotech Capital (GP), LLC, due to their interest in 667 and Baker Biotech Capital, L.P.'s right to receive an allocation of a portion of the profits from 667.

F3 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to the Funds. In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F4 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on board of directors of the Issuer (the "Board") and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the restricted stock units (each, an "RSU"). Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

F7 · ownership.nature: Includes beneficial ownership of 2,396 previously issued RSUs payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

SEC source: 0001209191-23-058693 · doc4.xml · nonDerivative · entry 2

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 1,709,393

F1 · price: The price reported in Column 4 is a weighted average price. These shares of common stock ("Common Stock") of Madrigal Pharmaceuticals, Inc. (the "Issuer") were traded by 667, L.P. ("667") and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds") in multiple transactions at prices ranging from $216.48 to $216.89, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission (the "Staff"), upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

F3 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to the Funds. In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F4 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on board of directors of the Issuer (the "Board") and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the restricted stock units (each, an "RSU"). Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

F7 · ownership.nature: Includes beneficial ownership of 2,396 previously issued RSUs payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

F8 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Brothers Life Sciences Capital, L.P. and (ii) Life Sciences, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I held directly by or held for the benefit of Life Sciences, a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital, L.P., a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital (GP), LLC, due to their interest in Life Sciences and Baker Brothers Life Sciences Capital, L.P.'s right to receive an allocation of a portion of the profits from Life Sciences.

SEC source: 0001209191-23-058693 · doc4.xml · nonDerivative · entry 1

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 179,279

F1 · price: The price reported in Column 4 is a weighted average price. These shares of common stock ("Common Stock") of Madrigal Pharmaceuticals, Inc. (the "Issuer") were traded by 667, L.P. ("667") and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds") in multiple transactions at prices ranging from $216.48 to $216.89, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission (the "Staff"), upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

F2 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Biotech Capital, L.P. and (ii) 667, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I held directly by or held for the benefit of 667, a limited partnership of which the sole general partner is Baker Biotech Capital, L.P., a limited partnership of which the sole general partner is Baker Biotech Capital (GP), LLC, due to their interest in 667 and Baker Biotech Capital, L.P.'s right to receive an allocation of a portion of the profits from 667.

F3 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to the Funds. In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F4 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on board of directors of the Issuer (the "Board") and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the restricted stock units (each, an "RSU"). Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

F7 · ownership.nature: Includes beneficial ownership of 2,396 previously issued RSUs payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

SEC source: 0000950170-23-070416 · ownership.xml · derivative · entry 8

Waltermire Robert E. · CIK 0001876996 · Senior VP, Chief Pharma Dev.

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 21,200

Underlying: Common Stock · 2,500 shares

Expires 2031-08-02

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_date: All shares issued pursuant to the exercise of the options reported herein represent 3,800 shares underlying an overall option award of 35,000 shares. All exercised options had vested. As to the overall option for 35,000 shares, 25% of the shares underlying the option vested on August 2, 2022 and, thereafter, 6.25% of the shares vested, or will vest, on the last day of each successive three-month period, provided the Reporting Person continues in service with the Issuer on each such date.

SEC source: 0000950170-23-070416 · ownership.xml · nonDerivative · entry 6

Waltermire Robert E. · CIK 0001876996 · Senior VP, Chief Pharma Dev.

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 5,667

SEC source: 0000950170-23-070416 · ownership.xml · nonDerivative · entry 5

Waltermire Robert E. · CIK 0001876996 · Senior VP, Chief Pharma Dev.

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 6,667

SEC source: 0000950170-23-070416 · ownership.xml · nonDerivative · entry 4

Waltermire Robert E. · CIK 0001876996 · Senior VP, Chief Pharma Dev.

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,167

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · kind: All shares issued pursuant to the exercise of the options reported herein represent 3,800 shares underlying an overall option award of 35,000 shares. All exercised options had vested. As to the overall option for 35,000 shares, 25% of the shares underlying the option vested on August 2, 2022 and, thereafter, 6.25% of the shares vested, or will vest, on the last day of each successive three-month period, provided the Reporting Person continues in service with the Issuer on each such date.

SEC source: 0001209191-23-058691 · doc4.xml · nonDerivative · entry 30

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 1,699,129

F19 · price: The price reported in Column 4 is a weighted average price. These shares were traded by 667 and Life Sciences in multiple transactions at prices ranging from $220.90 to $221.88, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

F2 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds"). In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F3 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F4 · ownership.nature: Includes beneficial ownership of 2,396 previously issued restricted stock units (each, an "RSU") payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on the board of directors of the Issuer and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the RSUs. Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

F7 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Brothers Life Sciences Capital, L.P. and (ii) Life Sciences, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I held directly by or held for the benefit of Life Sciences, a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital, L.P., a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital (GP), LLC, due to their interest in Life Sciences and Baker Brothers Life Sciences Capital, L.P.'s right to receive an allocation of a portion of the profits from Life Sciences.

SEC source: 0001209191-23-058691 · doc4.xml · nonDerivative · entry 29

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 178,461

F19 · price: The price reported in Column 4 is a weighted average price. These shares were traded by 667 and Life Sciences in multiple transactions at prices ranging from $220.90 to $221.88, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

F1 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Biotech Capital, L.P. and (ii) 667, L.P. ("667"), Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in common stock ("Common Stock") of Madrigal Pharmaceuticals, Inc. (the "Issuer") reported in column 5 of Table I held directly by or held for the benefit of 667, a limited partnership of which the sole general partner is Baker Biotech Capital, L.P., a limited partnership of which the sole general partner is Baker Biotech Capital (GP), LLC, due to their interest in 667 and Baker Biotech Capital, L.P.'s right to receive an allocation of a portion of the profits from 667.

F2 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds"). In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F3 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F4 · ownership.nature: Includes beneficial ownership of 2,396 previously issued restricted stock units (each, an "RSU") payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on the board of directors of the Issuer and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the RSUs. Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

SEC source: 0001209191-23-058691 · doc4.xml · nonDerivative · entry 28

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 1,695,272

F18 · price: The price reported in Column 4 is a weighted average price. These shares were traded by 667 and Life Sciences in multiple transactions at prices ranging from $219.99 to $220.87, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

F2 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds"). In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F3 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F4 · ownership.nature: Includes beneficial ownership of 2,396 previously issued restricted stock units (each, an "RSU") payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on the board of directors of the Issuer and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the RSUs. Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

F7 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Brothers Life Sciences Capital, L.P. and (ii) Life Sciences, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I held directly by or held for the benefit of Life Sciences, a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital, L.P., a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital (GP), LLC, due to their interest in Life Sciences and Baker Brothers Life Sciences Capital, L.P.'s right to receive an allocation of a portion of the profits from Life Sciences.

SEC source: 0001209191-23-058691 · doc4.xml · nonDerivative · entry 27

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 178,153

F18 · price: The price reported in Column 4 is a weighted average price. These shares were traded by 667 and Life Sciences in multiple transactions at prices ranging from $219.99 to $220.87, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

F1 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Biotech Capital, L.P. and (ii) 667, L.P. ("667"), Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in common stock ("Common Stock") of Madrigal Pharmaceuticals, Inc. (the "Issuer") reported in column 5 of Table I held directly by or held for the benefit of 667, a limited partnership of which the sole general partner is Baker Biotech Capital, L.P., a limited partnership of which the sole general partner is Baker Biotech Capital (GP), LLC, due to their interest in 667 and Baker Biotech Capital, L.P.'s right to receive an allocation of a portion of the profits from 667.

F2 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds"). In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F3 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F4 · ownership.nature: Includes beneficial ownership of 2,396 previously issued restricted stock units (each, an "RSU") payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on the board of directors of the Issuer and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the RSUs. Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

SEC source: 0001209191-23-058691 · doc4.xml · nonDerivative · entry 26

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 1,690,864

F17 · price: The price reported in Column 4 is a weighted average price. These shares were traded by 667 and Life Sciences in multiple transactions at prices ranging from $218.63 to $219.54, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

F2 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds"). In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F3 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F4 · ownership.nature: Includes beneficial ownership of 2,396 previously issued restricted stock units (each, an "RSU") payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on the board of directors of the Issuer and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the RSUs. Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

F7 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Brothers Life Sciences Capital, L.P. and (ii) Life Sciences, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I held directly by or held for the benefit of Life Sciences, a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital, L.P., a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital (GP), LLC, due to their interest in Life Sciences and Baker Brothers Life Sciences Capital, L.P.'s right to receive an allocation of a portion of the profits from Life Sciences.

SEC source: 0001209191-23-058691 · doc4.xml · nonDerivative · entry 25

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 177,801

F17 · price: The price reported in Column 4 is a weighted average price. These shares were traded by 667 and Life Sciences in multiple transactions at prices ranging from $218.63 to $219.54, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

F1 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Biotech Capital, L.P. and (ii) 667, L.P. ("667"), Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in common stock ("Common Stock") of Madrigal Pharmaceuticals, Inc. (the "Issuer") reported in column 5 of Table I held directly by or held for the benefit of 667, a limited partnership of which the sole general partner is Baker Biotech Capital, L.P., a limited partnership of which the sole general partner is Baker Biotech Capital (GP), LLC, due to their interest in 667 and Baker Biotech Capital, L.P.'s right to receive an allocation of a portion of the profits from 667.

F2 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds"). In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F3 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F4 · ownership.nature: Includes beneficial ownership of 2,396 previously issued restricted stock units (each, an "RSU") payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on the board of directors of the Issuer and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the RSUs. Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

SEC source: 0001209191-23-058691 · doc4.xml · nonDerivative · entry 24

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 1,675,859

F16 · price: The price reported in Column 4 is a weighted average price. These shares were traded by 667 and Life Sciences in multiple transactions at prices ranging from $217.67 to $218.00, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

F2 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds"). In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F3 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F4 · ownership.nature: Includes beneficial ownership of 2,396 previously issued restricted stock units (each, an "RSU") payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on the board of directors of the Issuer and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the RSUs. Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

F7 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Brothers Life Sciences Capital, L.P. and (ii) Life Sciences, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I held directly by or held for the benefit of Life Sciences, a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital, L.P., a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital (GP), LLC, due to their interest in Life Sciences and Baker Brothers Life Sciences Capital, L.P.'s right to receive an allocation of a portion of the profits from Life Sciences.

SEC source: 0001209191-23-058691 · doc4.xml · nonDerivative · entry 23

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 176,606

F16 · price: The price reported in Column 4 is a weighted average price. These shares were traded by 667 and Life Sciences in multiple transactions at prices ranging from $217.67 to $218.00, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

F1 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Biotech Capital, L.P. and (ii) 667, L.P. ("667"), Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in common stock ("Common Stock") of Madrigal Pharmaceuticals, Inc. (the "Issuer") reported in column 5 of Table I held directly by or held for the benefit of 667, a limited partnership of which the sole general partner is Baker Biotech Capital, L.P., a limited partnership of which the sole general partner is Baker Biotech Capital (GP), LLC, due to their interest in 667 and Baker Biotech Capital, L.P.'s right to receive an allocation of a portion of the profits from 667.

F2 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds"). In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F3 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F4 · ownership.nature: Includes beneficial ownership of 2,396 previously issued restricted stock units (each, an "RSU") payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on the board of directors of the Issuer and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the RSUs. Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

SEC source: 0001209191-23-058691 · doc4.xml · nonDerivative · entry 22

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 1,672,986

F2 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds"). In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F3 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F4 · ownership.nature: Includes beneficial ownership of 2,396 previously issued restricted stock units (each, an "RSU") payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on the board of directors of the Issuer and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the RSUs. Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

F7 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Brothers Life Sciences Capital, L.P. and (ii) Life Sciences, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I held directly by or held for the benefit of Life Sciences, a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital, L.P., a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital (GP), LLC, due to their interest in Life Sciences and Baker Brothers Life Sciences Capital, L.P.'s right to receive an allocation of a portion of the profits from Life Sciences.

SEC source: 0001209191-23-058691 · doc4.xml · nonDerivative · entry 21

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 176,377

F1 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Biotech Capital, L.P. and (ii) 667, L.P. ("667"), Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in common stock ("Common Stock") of Madrigal Pharmaceuticals, Inc. (the "Issuer") reported in column 5 of Table I held directly by or held for the benefit of 667, a limited partnership of which the sole general partner is Baker Biotech Capital, L.P., a limited partnership of which the sole general partner is Baker Biotech Capital (GP), LLC, due to their interest in 667 and Baker Biotech Capital, L.P.'s right to receive an allocation of a portion of the profits from 667.

F2 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds"). In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F3 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F4 · ownership.nature: Includes beneficial ownership of 2,396 previously issued restricted stock units (each, an "RSU") payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on the board of directors of the Issuer and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the RSUs. Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

SEC source: 0001209191-23-058691 · doc4.xml · nonDerivative · entry 20

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 1,672,801

F15 · price: The price reported in Column 4 is a weighted average price. These shares were traded by 667 and Life Sciences in multiple transactions at prices ranging from $216.50 to $216.92, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

F2 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds"). In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F3 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F4 · ownership.nature: Includes beneficial ownership of 2,396 previously issued restricted stock units (each, an "RSU") payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on the board of directors of the Issuer and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the RSUs. Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

F7 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Brothers Life Sciences Capital, L.P. and (ii) Life Sciences, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I held directly by or held for the benefit of Life Sciences, a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital, L.P., a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital (GP), LLC, due to their interest in Life Sciences and Baker Brothers Life Sciences Capital, L.P.'s right to receive an allocation of a portion of the profits from Life Sciences.

SEC source: 0001209191-23-058691 · doc4.xml · nonDerivative · entry 19

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 176,362

F15 · price: The price reported in Column 4 is a weighted average price. These shares were traded by 667 and Life Sciences in multiple transactions at prices ranging from $216.50 to $216.92, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

F1 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Biotech Capital, L.P. and (ii) 667, L.P. ("667"), Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in common stock ("Common Stock") of Madrigal Pharmaceuticals, Inc. (the "Issuer") reported in column 5 of Table I held directly by or held for the benefit of 667, a limited partnership of which the sole general partner is Baker Biotech Capital, L.P., a limited partnership of which the sole general partner is Baker Biotech Capital (GP), LLC, due to their interest in 667 and Baker Biotech Capital, L.P.'s right to receive an allocation of a portion of the profits from 667.

F2 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds"). In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F3 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F4 · ownership.nature: Includes beneficial ownership of 2,396 previously issued restricted stock units (each, an "RSU") payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on the board of directors of the Issuer and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the RSUs. Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

SEC source: 0001209191-23-058691 · doc4.xml · nonDerivative · entry 18

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 1,671,032

F14 · price: The price reported in Column 4 is a weighted average price. These shares were traded by 667 and Life Sciences in multiple transactions at prices ranging from $214.56 to $215.00, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

F2 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds"). In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F3 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F4 · ownership.nature: Includes beneficial ownership of 2,396 previously issued restricted stock units (each, an "RSU") payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on the board of directors of the Issuer and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the RSUs. Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

F7 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Brothers Life Sciences Capital, L.P. and (ii) Life Sciences, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I held directly by or held for the benefit of Life Sciences, a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital, L.P., a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital (GP), LLC, due to their interest in Life Sciences and Baker Brothers Life Sciences Capital, L.P.'s right to receive an allocation of a portion of the profits from Life Sciences.

SEC source: 0001209191-23-058691 · doc4.xml · nonDerivative · entry 17

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 176,221

F14 · price: The price reported in Column 4 is a weighted average price. These shares were traded by 667 and Life Sciences in multiple transactions at prices ranging from $214.56 to $215.00, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

F1 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Biotech Capital, L.P. and (ii) 667, L.P. ("667"), Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in common stock ("Common Stock") of Madrigal Pharmaceuticals, Inc. (the "Issuer") reported in column 5 of Table I held directly by or held for the benefit of 667, a limited partnership of which the sole general partner is Baker Biotech Capital, L.P., a limited partnership of which the sole general partner is Baker Biotech Capital (GP), LLC, due to their interest in 667 and Baker Biotech Capital, L.P.'s right to receive an allocation of a portion of the profits from 667.

F2 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds"). In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F3 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F4 · ownership.nature: Includes beneficial ownership of 2,396 previously issued restricted stock units (each, an "RSU") payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on the board of directors of the Issuer and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the RSUs. Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

SEC source: 0001209191-23-058691 · doc4.xml · nonDerivative · entry 16

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 1,670,364

F13 · price: The price reported in Column 4 is a weighted average price. These shares were traded by 667 and Life Sciences in multiple transactions at prices ranging from $213.45 to $213.97, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

F2 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds"). In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F3 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F4 · ownership.nature: Includes beneficial ownership of 2,396 previously issued restricted stock units (each, an "RSU") payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on the board of directors of the Issuer and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the RSUs. Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

F7 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Brothers Life Sciences Capital, L.P. and (ii) Life Sciences, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I held directly by or held for the benefit of Life Sciences, a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital, L.P., a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital (GP), LLC, due to their interest in Life Sciences and Baker Brothers Life Sciences Capital, L.P.'s right to receive an allocation of a portion of the profits from Life Sciences.

SEC source: 0001209191-23-058691 · doc4.xml · nonDerivative · entry 15

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 176,168

F13 · price: The price reported in Column 4 is a weighted average price. These shares were traded by 667 and Life Sciences in multiple transactions at prices ranging from $213.45 to $213.97, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

F1 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Biotech Capital, L.P. and (ii) 667, L.P. ("667"), Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in common stock ("Common Stock") of Madrigal Pharmaceuticals, Inc. (the "Issuer") reported in column 5 of Table I held directly by or held for the benefit of 667, a limited partnership of which the sole general partner is Baker Biotech Capital, L.P., a limited partnership of which the sole general partner is Baker Biotech Capital (GP), LLC, due to their interest in 667 and Baker Biotech Capital, L.P.'s right to receive an allocation of a portion of the profits from 667.

F2 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds"). In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F3 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F4 · ownership.nature: Includes beneficial ownership of 2,396 previously issued restricted stock units (each, an "RSU") payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on the board of directors of the Issuer and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the RSUs. Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

SEC source: 0001209191-23-058691 · doc4.xml · nonDerivative · entry 14

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 1,669,849

F12 · price: The price reported in Column 4 is a weighted average price. These shares were traded by 667 and Life Sciences in multiple transactions at prices ranging from $213.62 to $213.63, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

F2 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds"). In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F3 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F4 · ownership.nature: Includes beneficial ownership of 2,396 previously issued restricted stock units (each, an "RSU") payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on the board of directors of the Issuer and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the RSUs. Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

F7 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Brothers Life Sciences Capital, L.P. and (ii) Life Sciences, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I held directly by or held for the benefit of Life Sciences, a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital, L.P., a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital (GP), LLC, due to their interest in Life Sciences and Baker Brothers Life Sciences Capital, L.P.'s right to receive an allocation of a portion of the profits from Life Sciences.

SEC source: 0001209191-23-058691 · doc4.xml · nonDerivative · entry 13

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 176,127

F12 · price: The price reported in Column 4 is a weighted average price. These shares were traded by 667 and Life Sciences in multiple transactions at prices ranging from $213.62 to $213.63, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

F1 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Biotech Capital, L.P. and (ii) 667, L.P. ("667"), Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in common stock ("Common Stock") of Madrigal Pharmaceuticals, Inc. (the "Issuer") reported in column 5 of Table I held directly by or held for the benefit of 667, a limited partnership of which the sole general partner is Baker Biotech Capital, L.P., a limited partnership of which the sole general partner is Baker Biotech Capital (GP), LLC, due to their interest in 667 and Baker Biotech Capital, L.P.'s right to receive an allocation of a portion of the profits from 667.

F2 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds"). In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F3 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F4 · ownership.nature: Includes beneficial ownership of 2,396 previously issued restricted stock units (each, an "RSU") payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on the board of directors of the Issuer and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the RSUs. Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

SEC source: 0001209191-23-058691 · doc4.xml · nonDerivative · entry 12

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 1,669,664

F11 · price: The price reported in Column 4 is a weighted average price. These shares were traded by 667 and Life Sciences in multiple transactions at prices ranging from $212.00 to $212.15, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

F2 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds"). In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F3 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F4 · ownership.nature: Includes beneficial ownership of 2,396 previously issued restricted stock units (each, an "RSU") payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on the board of directors of the Issuer and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the RSUs. Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

F7 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Brothers Life Sciences Capital, L.P. and (ii) Life Sciences, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I held directly by or held for the benefit of Life Sciences, a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital, L.P., a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital (GP), LLC, due to their interest in Life Sciences and Baker Brothers Life Sciences Capital, L.P.'s right to receive an allocation of a portion of the profits from Life Sciences.

SEC source: 0001209191-23-058691 · doc4.xml · nonDerivative · entry 11

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 176,112

F11 · price: The price reported in Column 4 is a weighted average price. These shares were traded by 667 and Life Sciences in multiple transactions at prices ranging from $212.00 to $212.15, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

F1 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Biotech Capital, L.P. and (ii) 667, L.P. ("667"), Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in common stock ("Common Stock") of Madrigal Pharmaceuticals, Inc. (the "Issuer") reported in column 5 of Table I held directly by or held for the benefit of 667, a limited partnership of which the sole general partner is Baker Biotech Capital, L.P., a limited partnership of which the sole general partner is Baker Biotech Capital (GP), LLC, due to their interest in 667 and Baker Biotech Capital, L.P.'s right to receive an allocation of a portion of the profits from 667.

F2 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds"). In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F3 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F4 · ownership.nature: Includes beneficial ownership of 2,396 previously issued restricted stock units (each, an "RSU") payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on the board of directors of the Issuer and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the RSUs. Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

SEC source: 0001209191-23-058691 · doc4.xml · nonDerivative · entry 10

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 1,669,016

F2 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds"). In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F3 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F4 · ownership.nature: Includes beneficial ownership of 2,396 previously issued restricted stock units (each, an "RSU") payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on the board of directors of the Issuer and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the RSUs. Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

F7 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Brothers Life Sciences Capital, L.P. and (ii) Life Sciences, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I held directly by or held for the benefit of Life Sciences, a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital, L.P., a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital (GP), LLC, due to their interest in Life Sciences and Baker Brothers Life Sciences Capital, L.P.'s right to receive an allocation of a portion of the profits from Life Sciences.

SEC source: 0001209191-23-058691 · doc4.xml · nonDerivative · entry 9

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 176,060

F1 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Biotech Capital, L.P. and (ii) 667, L.P. ("667"), Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in common stock ("Common Stock") of Madrigal Pharmaceuticals, Inc. (the "Issuer") reported in column 5 of Table I held directly by or held for the benefit of 667, a limited partnership of which the sole general partner is Baker Biotech Capital, L.P., a limited partnership of which the sole general partner is Baker Biotech Capital (GP), LLC, due to their interest in 667 and Baker Biotech Capital, L.P.'s right to receive an allocation of a portion of the profits from 667.

F2 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds"). In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F3 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F4 · ownership.nature: Includes beneficial ownership of 2,396 previously issued restricted stock units (each, an "RSU") payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on the board of directors of the Issuer and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the RSUs. Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

SEC source: 0001209191-23-058691 · doc4.xml · nonDerivative · entry 8

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 1,668,923

F10 · price: The price reported in Column 4 is a weighted average price. These shares were traded by 667 and Life Sciences in multiple transactions at prices ranging from $208.51 to $208.76, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

F2 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds"). In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F3 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F4 · ownership.nature: Includes beneficial ownership of 2,396 previously issued restricted stock units (each, an "RSU") payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on the board of directors of the Issuer and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the RSUs. Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

F7 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Brothers Life Sciences Capital, L.P. and (ii) Life Sciences, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I held directly by or held for the benefit of Life Sciences, a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital, L.P., a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital (GP), LLC, due to their interest in Life Sciences and Baker Brothers Life Sciences Capital, L.P.'s right to receive an allocation of a portion of the profits from Life Sciences.

SEC source: 0001209191-23-058691 · doc4.xml · nonDerivative · entry 7

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 176,053

F10 · price: The price reported in Column 4 is a weighted average price. These shares were traded by 667 and Life Sciences in multiple transactions at prices ranging from $208.51 to $208.76, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

F1 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Biotech Capital, L.P. and (ii) 667, L.P. ("667"), Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in common stock ("Common Stock") of Madrigal Pharmaceuticals, Inc. (the "Issuer") reported in column 5 of Table I held directly by or held for the benefit of 667, a limited partnership of which the sole general partner is Baker Biotech Capital, L.P., a limited partnership of which the sole general partner is Baker Biotech Capital (GP), LLC, due to their interest in 667 and Baker Biotech Capital, L.P.'s right to receive an allocation of a portion of the profits from 667.

F2 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds"). In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F3 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F4 · ownership.nature: Includes beneficial ownership of 2,396 previously issued restricted stock units (each, an "RSU") payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on the board of directors of the Issuer and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the RSUs. Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

SEC source: 0001209191-23-058691 · doc4.xml · nonDerivative · entry 6

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 1,668,553

F9 · price: The price reported in Column 4 is a weighted average price. These shares were traded by 667 and Life Sciences in multiple transactions at prices ranging from $206.59 to $207.44, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

F2 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds"). In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F3 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F4 · ownership.nature: Includes beneficial ownership of 2,396 previously issued restricted stock units (each, an "RSU") payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on the board of directors of the Issuer and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the RSUs. Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

F7 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Brothers Life Sciences Capital, L.P. and (ii) Life Sciences, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I held directly by or held for the benefit of Life Sciences, a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital, L.P., a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital (GP), LLC, due to their interest in Life Sciences and Baker Brothers Life Sciences Capital, L.P.'s right to receive an allocation of a portion of the profits from Life Sciences.

SEC source: 0001209191-23-058691 · doc4.xml · nonDerivative · entry 5

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 176,023

F9 · price: The price reported in Column 4 is a weighted average price. These shares were traded by 667 and Life Sciences in multiple transactions at prices ranging from $206.59 to $207.44, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the Staff, upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

F1 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Biotech Capital, L.P. and (ii) 667, L.P. ("667"), Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in common stock ("Common Stock") of Madrigal Pharmaceuticals, Inc. (the "Issuer") reported in column 5 of Table I held directly by or held for the benefit of 667, a limited partnership of which the sole general partner is Baker Biotech Capital, L.P., a limited partnership of which the sole general partner is Baker Biotech Capital (GP), LLC, due to their interest in 667 and Baker Biotech Capital, L.P.'s right to receive an allocation of a portion of the profits from 667.

F2 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds"). In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F3 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F4 · ownership.nature: Includes beneficial ownership of 2,396 previously issued restricted stock units (each, an "RSU") payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on the board of directors of the Issuer and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the RSUs. Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

SEC source: 0001209191-23-058691 · doc4.xml · nonDerivative · entry 4

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 1,667,905

F8 · price: The price reported in Column 4 is a weighted average price. These shares of Common Stock were traded by 667 and Life Sciences in multiple transactions at prices ranging from $205.48 to $206.43, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission (the "Staff"), upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

F2 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds"). In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F3 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F4 · ownership.nature: Includes beneficial ownership of 2,396 previously issued restricted stock units (each, an "RSU") payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on the board of directors of the Issuer and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the RSUs. Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

F7 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Brothers Life Sciences Capital, L.P. and (ii) Life Sciences, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I held directly by or held for the benefit of Life Sciences, a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital, L.P., a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital (GP), LLC, due to their interest in Life Sciences and Baker Brothers Life Sciences Capital, L.P.'s right to receive an allocation of a portion of the profits from Life Sciences.

SEC source: 0001209191-23-058691 · doc4.xml · nonDerivative · entry 3

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 175,971

F8 · price: The price reported in Column 4 is a weighted average price. These shares of Common Stock were traded by 667 and Life Sciences in multiple transactions at prices ranging from $205.48 to $206.43, inclusive. The reporting persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission (the "Staff"), upon request, full information regarding the number of shares traded at each separate price within the range set forth in this footnote.

F1 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Biotech Capital, L.P. and (ii) 667, L.P. ("667"), Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in common stock ("Common Stock") of Madrigal Pharmaceuticals, Inc. (the "Issuer") reported in column 5 of Table I held directly by or held for the benefit of 667, a limited partnership of which the sole general partner is Baker Biotech Capital, L.P., a limited partnership of which the sole general partner is Baker Biotech Capital (GP), LLC, due to their interest in 667 and Baker Biotech Capital, L.P.'s right to receive an allocation of a portion of the profits from 667.

F2 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds"). In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F3 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F4 · ownership.nature: Includes beneficial ownership of 2,396 previously issued restricted stock units (each, an "RSU") payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on the board of directors of the Issuer and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the RSUs. Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

SEC source: 0001209191-23-058691 · doc4.xml · nonDerivative · entry 2

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director

667, L.P. · CIK 0001551139 · Director

BAKER JULIAN · CIK 0001087939 · Director

BAKER FELIX · CIK 0001087940 · Director

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director

Baker Brothers Life Sciences LP · CIK 0001363364 · Director

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 1,667,197

F2 · ownership.nature: Baker Bros. Advisors LP (the "Adviser") serves as the investment adviser to 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds"). In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held directly by the Funds or for the benefit of the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds or for the benefit of the Funds.

F3 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F4 · ownership.nature: Includes beneficial ownership of 2,396 previously issued restricted stock units (each, an "RSU") payable solely in Common Stock issued to each of Julian C. Baker, a managing member of the Adviser GP and Dr. Raymond Cheong, an employee of the Adviser, in their capacity as directors of the Issuer pursuant to the Issuer's Amended 2015 Stock Plan ("2015 Plan") of which the Funds may be deemed to own a portion.

F5 · ownership.nature: Pursuant to the policies of the Adviser, Julian C. Baker and Dr. Cheong do not have a right to any of the Issuer's securities issued as compensation for their service on the board of directors of the Issuer and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the RSUs. Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the RSUs and any Common Stock acquired upon the vesting of RSUs (i.e. no direct pecuniary interest).

F6 · ownership.nature: Pursuant to agreements between Julian C. Baker, Dr. Cheong and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the RSUs and any Common Stock received as a result of the vesting of RSUs.

F7 · ownership.nature: After giving effect to the transactions reported herein and as a result of their ownership interest in (i) Baker Brothers Life Sciences Capital, L.P. and (ii) Life Sciences, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I held directly by or held for the benefit of Life Sciences, a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital, L.P., a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital (GP), LLC, due to their interest in Life Sciences and Baker Brothers Life Sciences Capital, L.P.'s right to receive an allocation of a portion of the profits from Life Sciences.