KOD

SEC source: 0001209191-22-005629 · doc4.xml · nonDerivative · entry 4

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director · 10% owner

667, L.P. · CIK 0001551139 · Director · 10% owner

BAKER JULIAN · CIK 0001087939 · Director · 10% owner

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director · 10% owner

Baker Brothers Life Sciences LP · CIK 0001363364 · Director · 10% owner

BAKER FELIX · CIK 0001087940 · Director · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 14,285,631

F6 · price: The price reported in Column 4 is a weighted average price. These shares were traded by the Funds in multiple transactions at prices ranging from $51.48 to $51.83, 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 Life Sciences and 667, L.P. ("667", and together with Life Sciences, 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 by 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 by 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 by 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 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: 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, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I beneficially owned by 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: 0001209191-22-005629 · doc4.xml · nonDerivative · entry 3

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director · 10% owner

667, L.P. · CIK 0001551139 · Director · 10% owner

BAKER JULIAN · CIK 0001087939 · Director · 10% owner

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director · 10% owner

Baker Brothers Life Sciences LP · CIK 0001363364 · Director · 10% owner

BAKER FELIX · CIK 0001087940 · Director · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 1,159,043

F6 · price: The price reported in Column 4 is a weighted average price. These shares were traded by the Funds in multiple transactions at prices ranging from $51.48 to $51.83, 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 Life Sciences and 667, L.P. ("667", and together with Life Sciences, 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 by 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 by 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 by 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 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.

F7 · ownership.nature: After giving effect to the transactions 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 of the Issuer reported in column 5 of Table I directly held by 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.

SEC source: 0001209191-22-005629 · doc4.xml · nonDerivative · entry 2

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director · 10% owner

667, L.P. · CIK 0001551139 · Director · 10% owner

BAKER JULIAN · CIK 0001087939 · Director · 10% owner

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director · 10% owner

Baker Brothers Life Sciences LP · CIK 0001363364 · Director · 10% owner

BAKER FELIX · CIK 0001087940 · Director · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 14,231,607

F5 · price: The price reported in Column 4 is a weighted average price. These shares were traded by Life Sciences in multiple transactions at prices ranging from $51.18 to $51.74, 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 Life Sciences and 667, L.P. ("667", and together with Life Sciences, 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 by 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 by 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 by 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 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: 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, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I beneficially owned by 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: 0001209191-22-005629 · doc4.xml · nonDerivative · entry 1

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director · 10% owner

667, L.P. · CIK 0001551139 · Director · 10% owner

BAKER JULIAN · CIK 0001087939 · Director · 10% owner

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director · 10% owner

Baker Brothers Life Sciences LP · CIK 0001363364 · Director · 10% owner

BAKER FELIX · CIK 0001087940 · Director · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 14,114,316

F1 · price: The price reported in Column 4 is a weighted average price. These shares of common stock ("Common Stock") of Kodiak Sciences Inc. (the "Issuer") were traded by Baker Brothers Life Sciences, L.P. ("Life Sciences") in multiple transactions at prices ranging from $51.74 to $52.74, 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 Life Sciences and 667, L.P. ("667", and together with Life Sciences, 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 by 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 by 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 by 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 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: 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, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I beneficially owned by 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: 0001209191-22-004852 · doc4.xml · nonDerivative · entry 11

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director · 10% owner

667, L.P. · CIK 0001551139 · Director · 10% owner

BAKER JULIAN · CIK 0001087939 · Director · 10% owner

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director · 10% owner

Baker Brothers Life Sciences LP · CIK 0001363364 · Director · 10% owner

BAKER FELIX · CIK 0001087940 · Director · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 14,027,837

F13 · price: The price reported in Column 4 is a weighted average price. These shares were traded by Life Sciences in multiple transactions at prices ranging from $58.54 to $59.00, 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 by 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 by 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 by 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 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: 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, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I beneficially owned by 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: 0001209191-22-004852 · doc4.xml · nonDerivative · entry 10

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director · 10% owner

667, L.P. · CIK 0001551139 · Director · 10% owner

BAKER JULIAN · CIK 0001087939 · Director · 10% owner

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director · 10% owner

Baker Brothers Life Sciences LP · CIK 0001363364 · Director · 10% owner

BAKER FELIX · CIK 0001087940 · Director · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 14,022,337

F12 · price: The price reported in Column 4 is a weighted average price. These shares were traded by Life Sciences in multiple transactions at prices ranging from $58.59 to $59.59, 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 by 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 by 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 by 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 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: 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, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I beneficially owned by 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: 0001209191-22-004852 · doc4.xml · nonDerivative · entry 9

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director · 10% owner

667, L.P. · CIK 0001551139 · Director · 10% owner

BAKER JULIAN · CIK 0001087939 · Director · 10% owner

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director · 10% owner

Baker Brothers Life Sciences LP · CIK 0001363364 · Director · 10% owner

BAKER FELIX · CIK 0001087940 · Director · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 13,964,790

F11 · price: The price reported in Column 4 is a weighted average price. These shares were traded by Life Sciences in multiple transactions at prices ranging from $58.71 to $59.00, 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 by 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 by 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 by 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 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: 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, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I beneficially owned by 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: 0001209191-22-004852 · doc4.xml · nonDerivative · entry 8

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director · 10% owner

667, L.P. · CIK 0001551139 · Director · 10% owner

BAKER JULIAN · CIK 0001087939 · Director · 10% owner

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director · 10% owner

Baker Brothers Life Sciences LP · CIK 0001363364 · Director · 10% owner

BAKER FELIX · CIK 0001087940 · Director · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 13,955,440

F10 · price: The price reported in Column 4 is a weighted average price. These shares were traded by Life Sciences in multiple transactions at prices ranging from $57.59 to $58.59, 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 by 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 by 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 by 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 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: 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, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I beneficially owned by 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: 0001209191-22-004852 · doc4.xml · nonDerivative · entry 7

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director · 10% owner

667, L.P. · CIK 0001551139 · Director · 10% owner

BAKER JULIAN · CIK 0001087939 · Director · 10% owner

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director · 10% owner

Baker Brothers Life Sciences LP · CIK 0001363364 · Director · 10% owner

BAKER FELIX · CIK 0001087940 · Director · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 13,823,073

F9 · price: The price reported in Column 4 is a weighted average price. These shares were traded by Life Sciences in multiple transactions at prices ranging from $56.90 to $57.89, 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: 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 by 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 by 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 by 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 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: 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, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I beneficially owned by 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: 0001209191-22-004852 · doc4.xml · nonDerivative · entry 6

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director · 10% owner

667, L.P. · CIK 0001551139 · Director · 10% owner

BAKER JULIAN · CIK 0001087939 · Director · 10% owner

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director · 10% owner

Baker Brothers Life Sciences LP · CIK 0001363364 · Director · 10% owner

BAKER FELIX · CIK 0001087940 · Director · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 13,797,173

F8 · price: The price reported in Column 4 is a weighted average price. These shares were traded by Life Sciences in multiple transactions at prices ranging from $56.59 to $57.59, 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 by 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 by 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 by 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 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: 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, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I beneficially owned by 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: 0001209191-22-004852 · doc4.xml · nonDerivative · entry 5

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director · 10% owner

667, L.P. · CIK 0001551139 · Director · 10% owner

BAKER JULIAN · CIK 0001087939 · Director · 10% owner

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director · 10% owner

Baker Brothers Life Sciences LP · CIK 0001363364 · Director · 10% owner

BAKER FELIX · CIK 0001087940 · Director · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 13,681,090

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 by 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 by 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 by 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 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: 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, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I beneficially owned by 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: 0001209191-22-004852 · doc4.xml · nonDerivative · entry 4

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director · 10% owner

667, L.P. · CIK 0001551139 · Director · 10% owner

BAKER JULIAN · CIK 0001087939 · Director · 10% owner

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director · 10% owner

Baker Brothers Life Sciences LP · CIK 0001363364 · Director · 10% owner

BAKER FELIX · CIK 0001087940 · Director · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 13,679,890

F7 · price: The price reported in Column 4 is a weighted average price. These shares were traded by Life Sciences in multiple transactions at prices ranging from $56.17 to $56.59, 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 by 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 by 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 by 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 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: 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, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I beneficially owned by 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: 0001209191-22-004852 · doc4.xml · nonDerivative · entry 3

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director · 10% owner

667, L.P. · CIK 0001551139 · Director · 10% owner

BAKER JULIAN · CIK 0001087939 · Director · 10% owner

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director · 10% owner

Baker Brothers Life Sciences LP · CIK 0001363364 · Director · 10% owner

BAKER FELIX · CIK 0001087940 · Director · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 13,660,140

F6 · price: The price reported in Column 4 is a weighted average price. These shares were traded by Life Sciences in multiple transactions at prices ranging from $56.80 to $57.80, 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 by 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 by 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 by 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 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: 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, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I beneficially owned by 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: 0001209191-22-004852 · doc4.xml · nonDerivative · entry 2

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director · 10% owner

667, L.P. · CIK 0001551139 · Director · 10% owner

BAKER JULIAN · CIK 0001087939 · Director · 10% owner

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director · 10% owner

Baker Brothers Life Sciences LP · CIK 0001363364 · Director · 10% owner

BAKER FELIX · CIK 0001087940 · Director · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 13,628,933

F4 · price: The price reported in Column 4 is a weighted average price. These shares were traded by Life Sciences in multiple transactions at prices ranging from $56.46 to $56.80, 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 by 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 by 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 by 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 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: 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, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I beneficially owned by 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: 0001209191-22-004636 · doc4.xml · derivative · entry 7

EHRLICH JASON · CIK 0001754049 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 218,538

Underlying: Common Stock · 6,950 shares

Expires 2028-08-29

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.

F7 · derivative.exercise_date: Twenty-five percent of the shares subject to the option vested on September 1, 2019, and 1/48th of the shares subject to the option vest on the same day of each month thereafter.

SEC source: 0001209191-22-004636 · doc4.xml · nonDerivative · entry 6

EHRLICH JASON · CIK 0001754049 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 51,541

F1 · kind: The sales reported in this Form 4 were effected pursuant to a 10b5-1 trading plan.

F6 · price: The price reported in Column 4 is a weighted-average price. The shares were sold in multiple transactions ranging from $66.91 to $66.99, inclusive.

SEC source: 0001209191-22-004636 · doc4.xml · nonDerivative · entry 5

EHRLICH JASON · CIK 0001754049 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 51,739

F1 · kind: The sales reported in this Form 4 were effected pursuant to a 10b5-1 trading plan.

F5 · price: The price reported in Column 4 is a weighted-average price. The shares were sold in multiple transactions ranging from $65.85 to $66.41, inclusive.

SEC source: 0001209191-22-004636 · doc4.xml · nonDerivative · entry 4

EHRLICH JASON · CIK 0001754049 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 52,272

F1 · kind: The sales reported in this Form 4 were effected pursuant to a 10b5-1 trading plan.

F4 · price: The price reported in Column 4 is a weighted-average price. The shares were sold in multiple transactions ranging from $64.395 to $65.33, inclusive.

SEC source: 0001209191-22-004636 · doc4.xml · nonDerivative · entry 3

EHRLICH JASON · CIK 0001754049 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 55,267

F1 · kind: The sales reported in this Form 4 were effected pursuant to a 10b5-1 trading plan.

F3 · price: The price reported in Column 4 is a weighted-average price. The shares were sold in multiple transactions ranging from $63.135 to $64.11, inclusive.

SEC source: 0001209191-22-004636 · doc4.xml · nonDerivative · entry 2

EHRLICH JASON · CIK 0001754049 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 57,683

F1 · kind: The sales reported in this Form 4 were effected pursuant to a 10b5-1 trading plan.

F2 · price: The price reported in Column 4 is a weighted-average price. The shares were sold in multiple transactions ranging from $62.02 to $62.98, inclusive. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer, or the Staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in these footnotes.

SEC source: 0001209191-22-004636 · doc4.xml · nonDerivative · entry 1

EHRLICH JASON · CIK 0001754049 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 58,491

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.

SEC source: 0001209191-21-070934 · doc4.xml · derivative · entry 5

EHRLICH JASON · CIK 0001754049 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 225,488

Underlying: Common Stock · 6,950 shares

Expires 2028-08-29

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.

F5 · derivative.exercise_date: Twenty-five percent of the shares subject to the option vested on September 1, 2019, and 1/48th of the shares subject to the option vest on the same day of each month thereafter.

SEC source: 0001209191-21-070934 · doc4.xml · nonDerivative · entry 4

EHRLICH JASON · CIK 0001754049 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 51,541

F1 · kind: The sales reported in this Form 4 were effected pursuant to a 10b5-1 trading plan.

F4 · price: The price reported in Column 4 is a weighted-average price. The shares were sold in multiple transactions ranging from $88.13 to $89.01, inclusive.

SEC source: 0001209191-21-070934 · doc4.xml · nonDerivative · entry 3

EHRLICH JASON · CIK 0001754049 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 53,250

F1 · kind: The sales reported in this Form 4 were effected pursuant to a 10b5-1 trading plan.

F3 · price: The price reported in Column 4 is a weighted-average price. The shares were sold in multiple transactions ranging from $87.06 to $88.035, inclusive.

SEC source: 0001209191-21-070934 · doc4.xml · nonDerivative · entry 2

EHRLICH JASON · CIK 0001754049 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 56,959

F1 · kind: The sales reported in this Form 4 were effected pursuant to a 10b5-1 trading plan.

F2 · price: The price reported in Column 4 is a weighted-average price. The shares were sold in multiple transactions ranging from $86.085 to $87.025, inclusive. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer, or the Staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in these footnotes.

SEC source: 0001209191-21-070934 · doc4.xml · nonDerivative · entry 1

EHRLICH JASON · CIK 0001754049 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 58,491

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.

SEC source: 0001209191-21-066813 · doc4.xml · derivative · entry 7

EHRLICH JASON · CIK 0001754049 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 232,438

Underlying: Common Stock · 6,950 shares

Expires 2028-08-29

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.

F6 · derivative.exercise_date: Twenty-five percent of the shares subject to the option vested on September 1, 2019, and 1/48th of the shares subject to the option vest on the same day of each month thereafter.

SEC source: 0001209191-21-066813 · doc4.xml · nonDerivative · entry 6

EHRLICH JASON · CIK 0001754049 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 51,541

F1 · kind: The sales reported in this Form 4 were effected pursuant to a 10b5-1 trading plan.

F5 · price: The price reported in Column 4 is a weighted-average price. The shares were sold in multiple transactions ranging from $101.17 to $101.27, inclusive.

SEC source: 0001209191-21-066813 · doc4.xml · nonDerivative · entry 5

EHRLICH JASON · CIK 0001754049 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 51,647

F1 · kind: The sales reported in this Form 4 were effected pursuant to a 10b5-1 trading plan.

F4 · price: The price reported in Column 4 is a weighted-average price. The shares were sold in multiple transactions ranging from $100.155 to $101.095, inclusive.

SEC source: 0001209191-21-066813 · doc4.xml · nonDerivative · entry 4

EHRLICH JASON · CIK 0001754049 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 52,718

F1 · kind: The sales reported in this Form 4 were effected pursuant to a 10b5-1 trading plan.

F3 · price: The price reported in Column 4 is a weighted-average price. The shares were sold in multiple transactions ranging from $99.12 to $100.08, inclusive.

SEC source: 0001209191-21-066813 · doc4.xml · nonDerivative · entry 3

EHRLICH JASON · CIK 0001754049 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 54,599

F1 · kind: The sales reported in this Form 4 were effected pursuant to a 10b5-1 trading plan.

F2 · price: The price reported in Column 4 is a weighted-average price. The shares were sold in multiple transactions ranging from $98.06 to $99.04, inclusive. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer, or the Staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in these footnotes.

SEC source: 0001209191-21-066813 · doc4.xml · nonDerivative · entry 2

EHRLICH JASON · CIK 0001754049 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 58,300

F1 · kind: The sales reported in this Form 4 were effected pursuant to a 10b5-1 trading plan.

SEC source: 0001209191-21-066813 · doc4.xml · nonDerivative · entry 1

EHRLICH JASON · CIK 0001754049 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 58,491

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.

SEC source: 0001209191-21-064246 · doc4.xml · nonDerivative · entry 2

BORGESON JOHN A. · CIK 0001754045 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 169,443

F1 · kind: The sales reported in this Form 4 were effected pursuant to a 10b5-1 trading plan.

F3 · price: The price reported in Column 4 is a weighted-average price. The shares were sold in multiple transactions ranging from $116.29 to $116.625, inclusive.

SEC source: 0001209191-21-064246 · doc4.xml · nonDerivative · entry 1

BORGESON JOHN A. · CIK 0001754045 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 169,647

F1 · kind: The sales reported in this Form 4 were effected pursuant to a 10b5-1 trading plan.

F2 · price: The price reported in Column 4 is a weighted-average price. The shares were sold in multiple transactions ranging from $115.00 to $115.95, inclusive. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer, or the Staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in these footnotes.

SEC source: 0001209191-21-061375 · doc4.xml · derivative · entry 4

EHRLICH JASON · CIK 0001754049 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 239,388

Underlying: Common Stock · 6,950 shares

Expires 2028-08-29

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.

F4 · derivative.exercise_date: Twenty-five percent of the shares subject to the option vested on September 1, 2019, and 1/48th of the shares subject to the option vest on the same day of each month thereafter.

SEC source: 0001209191-21-061375 · doc4.xml · nonDerivative · entry 3

EHRLICH JASON · CIK 0001754049 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 51,541

F1 · kind: The sales reported in this Form 4 were effected pursuant to a 10b5-1 trading plan.

F3 · price: The price reported in Column 4 is a weighted-average price. The shares were sold in multiple transactions ranging from $112.23 to $113.16, inclusive.

SEC source: 0001209191-21-061375 · doc4.xml · nonDerivative · entry 2

EHRLICH JASON · CIK 0001754049 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 52,793

F1 · kind: The sales reported in this Form 4 were effected pursuant to a 10b5-1 trading plan.

F2 · price: The price reported in Column 4 is a weighted-average price. The shares were sold in multiple transactions ranging from $111.16 to $112.04, inclusive. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer, or the Staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in these footnotes.

SEC source: 0001209191-21-061375 · doc4.xml · nonDerivative · entry 1

EHRLICH JASON · CIK 0001754049 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 58,491

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.

SEC source: 0001638599-21-000734 · doc4_7361.xml · nonDerivative · entry 5

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director · 10% owner

667, L.P. · CIK 0001551139 · Director · 10% owner

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director · 10% owner

Baker Brothers Life Sciences LP · CIK 0001363364 · Director · 10% owner

BAKER FELIX · CIK 0001087940 · Director · 10% owner

BAKER JULIAN · CIK 0001087939 · Director · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 13,526,726

F10 · price: The price reported in Column 4 is a weighted average price. These shares were traded by Life Sciences in multiple transactions at prices ranging from $95.15 to $95.98, 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: 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, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I directly held by 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.

F4 · 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 by 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 by 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 by the Funds.

F5 · 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 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.

SEC source: 0001638599-21-000734 · doc4_7361.xml · derivative · entry 7

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director · 10% owner

667, L.P. · CIK 0001551139 · Director · 10% owner

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director · 10% owner

Baker Brothers Life Sciences LP · CIK 0001363364 · Director · 10% owner

BAKER FELIX · CIK 0001087940 · Director · 10% owner

BAKER JULIAN · CIK 0001087939 · Director · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 0

Underlying: Common Stock · 138,815 shares

Expires 2022-08-11

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.

F2 · derivative.exercise_price: On September 29, 2021, 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds") exercised warrants to purchase 11,184 and 138,815 shares of Common Stock of the Issuer, respectively, for $0.01 per share ("Prefunded Warrants"). 667 and Life Sciences paid the exercise price on a cashless basis, resulting in the Issuer withholding 2 and 14 shares of Common Stock for 667 and Life Sciences, respectively, of the Prefunded Warrant shares to pay the exercise price and issuing to 667 and Life Sciences the remaining 11,182 and 138,801 shares of Common Stock, respectively. The Issuer also paid $4.50 and $1.95 to 667 and Life Sciences, respectively, in cash in lieu of fractional shares. The Issuer's Board of Directors approved the exercise of the Prefunded Warrants by 667 and Life Sciences on the cashless basis described in this footnote in advance of such exercise.

F7 · price: Pursuant to Instruction 4(c)(iii), this response has been left blank.

F6 · derivative.exercise_date: Represents Prefunded Warrants exercisable at any time, at the holder's election, on a 1-for-1 basis into Common Stock. The Prefunded Warrants had an expiration date of August 11, 2022.

F6 · derivative.expiration_date: Represents Prefunded Warrants exercisable at any time, at the holder's election, on a 1-for-1 basis into Common Stock. The Prefunded Warrants had an expiration date of August 11, 2022.

F2 · ownership.nature: On September 29, 2021, 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds") exercised warrants to purchase 11,184 and 138,815 shares of Common Stock of the Issuer, respectively, for $0.01 per share ("Prefunded Warrants"). 667 and Life Sciences paid the exercise price on a cashless basis, resulting in the Issuer withholding 2 and 14 shares of Common Stock for 667 and Life Sciences, respectively, of the Prefunded Warrant shares to pay the exercise price and issuing to 667 and Life Sciences the remaining 11,182 and 138,801 shares of Common Stock, respectively. The Issuer also paid $4.50 and $1.95 to 667 and Life Sciences, respectively, in cash in lieu of fractional shares. The Issuer's Board of Directors approved the exercise of the Prefunded Warrants by 667 and Life Sciences on the cashless basis described in this footnote in advance of such exercise.

F4 · 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 by 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 by 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 by the Funds.

F5 · 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 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.

F9 · ownership.nature: As a result of their ownership interest in (i) Baker Brothers Life Sciences Capital L.P. and (ii) Life Sciences, Felix J. Baker and Julian C. Baker may have been deemed to have had an indirect pecuniary interest in Prefunded Warrants reported in column 7 of Table II that were directly held by 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: 0001638599-21-000734 · doc4_7361.xml · derivative · entry 6

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director · 10% owner

667, L.P. · CIK 0001551139 · Director · 10% owner

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director · 10% owner

Baker Brothers Life Sciences LP · CIK 0001363364 · Director · 10% owner

BAKER FELIX · CIK 0001087940 · Director · 10% owner

BAKER JULIAN · CIK 0001087939 · Director · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 0

Underlying: Common Stock · 11,184 shares

Expires 2022-08-11

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.

F2 · derivative.exercise_price: On September 29, 2021, 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds") exercised warrants to purchase 11,184 and 138,815 shares of Common Stock of the Issuer, respectively, for $0.01 per share ("Prefunded Warrants"). 667 and Life Sciences paid the exercise price on a cashless basis, resulting in the Issuer withholding 2 and 14 shares of Common Stock for 667 and Life Sciences, respectively, of the Prefunded Warrant shares to pay the exercise price and issuing to 667 and Life Sciences the remaining 11,182 and 138,801 shares of Common Stock, respectively. The Issuer also paid $4.50 and $1.95 to 667 and Life Sciences, respectively, in cash in lieu of fractional shares. The Issuer's Board of Directors approved the exercise of the Prefunded Warrants by 667 and Life Sciences on the cashless basis described in this footnote in advance of such exercise.

F7 · price: Pursuant to Instruction 4(c)(iii), this response has been left blank.

F6 · derivative.exercise_date: Represents Prefunded Warrants exercisable at any time, at the holder's election, on a 1-for-1 basis into Common Stock. The Prefunded Warrants had an expiration date of August 11, 2022.

F6 · derivative.expiration_date: Represents Prefunded Warrants exercisable at any time, at the holder's election, on a 1-for-1 basis into Common Stock. The Prefunded Warrants had an expiration date of August 11, 2022.

F2 · ownership.nature: On September 29, 2021, 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds") exercised warrants to purchase 11,184 and 138,815 shares of Common Stock of the Issuer, respectively, for $0.01 per share ("Prefunded Warrants"). 667 and Life Sciences paid the exercise price on a cashless basis, resulting in the Issuer withholding 2 and 14 shares of Common Stock for 667 and Life Sciences, respectively, of the Prefunded Warrant shares to pay the exercise price and issuing to 667 and Life Sciences the remaining 11,182 and 138,801 shares of Common Stock, respectively. The Issuer also paid $4.50 and $1.95 to 667 and Life Sciences, respectively, in cash in lieu of fractional shares. The Issuer's Board of Directors approved the exercise of the Prefunded Warrants by 667 and Life Sciences on the cashless basis described in this footnote in advance of such exercise.

F4 · 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 by 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 by 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 by the Funds.

F5 · 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 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.

F8 · ownership.nature: 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 have been deemed to have had an indirect pecuniary interest in Prefunded Warrants reported in column 7 of Table II that were directly held by 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.

SEC source: 0001638599-21-000734 · doc4_7361.xml · nonDerivative · entry 4

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director · 10% owner

667, L.P. · CIK 0001551139 · Director · 10% owner

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director · 10% owner

Baker Brothers Life Sciences LP · CIK 0001363364 · Director · 10% owner

BAKER FELIX · CIK 0001087940 · Director · 10% owner

BAKER JULIAN · CIK 0001087939 · Director · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 13,439,794

F2 · shares: On September 29, 2021, 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds") exercised warrants to purchase 11,184 and 138,815 shares of Common Stock of the Issuer, respectively, for $0.01 per share ("Prefunded Warrants"). 667 and Life Sciences paid the exercise price on a cashless basis, resulting in the Issuer withholding 2 and 14 shares of Common Stock for 667 and Life Sciences, respectively, of the Prefunded Warrant shares to pay the exercise price and issuing to 667 and Life Sciences the remaining 11,182 and 138,801 shares of Common Stock, respectively. The Issuer also paid $4.50 and $1.95 to 667 and Life Sciences, respectively, in cash in lieu of fractional shares. The Issuer's Board of Directors approved the exercise of the Prefunded Warrants by 667 and Life Sciences on the cashless basis described in this footnote in advance of such exercise.

F2 · price: On September 29, 2021, 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds") exercised warrants to purchase 11,184 and 138,815 shares of Common Stock of the Issuer, respectively, for $0.01 per share ("Prefunded Warrants"). 667 and Life Sciences paid the exercise price on a cashless basis, resulting in the Issuer withholding 2 and 14 shares of Common Stock for 667 and Life Sciences, respectively, of the Prefunded Warrant shares to pay the exercise price and issuing to 667 and Life Sciences the remaining 11,182 and 138,801 shares of Common Stock, respectively. The Issuer also paid $4.50 and $1.95 to 667 and Life Sciences, respectively, in cash in lieu of fractional shares. The Issuer's Board of Directors approved the exercise of the Prefunded Warrants by 667 and Life Sciences on the cashless basis described in this footnote in advance of such exercise.

F3 · 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, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I directly held by 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.

F4 · 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 by 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 by 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 by the Funds.

F5 · 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 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.

SEC source: 0001638599-21-000734 · doc4_7361.xml · nonDerivative · entry 3

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director · 10% owner

667, L.P. · CIK 0001551139 · Director · 10% owner

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director · 10% owner

Baker Brothers Life Sciences LP · CIK 0001363364 · Director · 10% owner

BAKER FELIX · CIK 0001087940 · Director · 10% owner

BAKER JULIAN · CIK 0001087939 · Director · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 13,439,808

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.

F2 · shares: On September 29, 2021, 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds") exercised warrants to purchase 11,184 and 138,815 shares of Common Stock of the Issuer, respectively, for $0.01 per share ("Prefunded Warrants"). 667 and Life Sciences paid the exercise price on a cashless basis, resulting in the Issuer withholding 2 and 14 shares of Common Stock for 667 and Life Sciences, respectively, of the Prefunded Warrant shares to pay the exercise price and issuing to 667 and Life Sciences the remaining 11,182 and 138,801 shares of Common Stock, respectively. The Issuer also paid $4.50 and $1.95 to 667 and Life Sciences, respectively, in cash in lieu of fractional shares. The Issuer's Board of Directors approved the exercise of the Prefunded Warrants by 667 and Life Sciences on the cashless basis described in this footnote in advance of such exercise.

F2 · price: On September 29, 2021, 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds") exercised warrants to purchase 11,184 and 138,815 shares of Common Stock of the Issuer, respectively, for $0.01 per share ("Prefunded Warrants"). 667 and Life Sciences paid the exercise price on a cashless basis, resulting in the Issuer withholding 2 and 14 shares of Common Stock for 667 and Life Sciences, respectively, of the Prefunded Warrant shares to pay the exercise price and issuing to 667 and Life Sciences the remaining 11,182 and 138,801 shares of Common Stock, respectively. The Issuer also paid $4.50 and $1.95 to 667 and Life Sciences, respectively, in cash in lieu of fractional shares. The Issuer's Board of Directors approved the exercise of the Prefunded Warrants by 667 and Life Sciences on the cashless basis described in this footnote in advance of such exercise.

F3 · 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, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in Common Stock reported in column 5 of Table I directly held by 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.

F4 · 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 by 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 by 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 by the Funds.

F5 · 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 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.

SEC source: 0001638599-21-000734 · doc4_7361.xml · nonDerivative · entry 2

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director · 10% owner

667, L.P. · CIK 0001551139 · Director · 10% owner

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director · 10% owner

Baker Brothers Life Sciences LP · CIK 0001363364 · Director · 10% owner

BAKER FELIX · CIK 0001087940 · Director · 10% owner

BAKER JULIAN · CIK 0001087939 · Director · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 1,154,578

F2 · shares: On September 29, 2021, 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds") exercised warrants to purchase 11,184 and 138,815 shares of Common Stock of the Issuer, respectively, for $0.01 per share ("Prefunded Warrants"). 667 and Life Sciences paid the exercise price on a cashless basis, resulting in the Issuer withholding 2 and 14 shares of Common Stock for 667 and Life Sciences, respectively, of the Prefunded Warrant shares to pay the exercise price and issuing to 667 and Life Sciences the remaining 11,182 and 138,801 shares of Common Stock, respectively. The Issuer also paid $4.50 and $1.95 to 667 and Life Sciences, respectively, in cash in lieu of fractional shares. The Issuer's Board of Directors approved the exercise of the Prefunded Warrants by 667 and Life Sciences on the cashless basis described in this footnote in advance of such exercise.

F2 · price: On September 29, 2021, 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds") exercised warrants to purchase 11,184 and 138,815 shares of Common Stock of the Issuer, respectively, for $0.01 per share ("Prefunded Warrants"). 667 and Life Sciences paid the exercise price on a cashless basis, resulting in the Issuer withholding 2 and 14 shares of Common Stock for 667 and Life Sciences, respectively, of the Prefunded Warrant shares to pay the exercise price and issuing to 667 and Life Sciences the remaining 11,182 and 138,801 shares of Common Stock, respectively. The Issuer also paid $4.50 and $1.95 to 667 and Life Sciences, respectively, in cash in lieu of fractional shares. The Issuer's Board of Directors approved the exercise of the Prefunded Warrants by 667 and Life Sciences on the cashless basis described in this footnote in advance of such exercise.

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 Kodiak Sciences Inc. (the "Issuer") reported in column 5 of Table I directly held by 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.

F4 · 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 by 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 by 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 by the Funds.

F5 · 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 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.

SEC source: 0001638599-21-000734 · doc4_7361.xml · nonDerivative · entry 1

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director · 10% owner

667, L.P. · CIK 0001551139 · Director · 10% owner

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director · 10% owner

Baker Brothers Life Sciences LP · CIK 0001363364 · Director · 10% owner

BAKER FELIX · CIK 0001087940 · Director · 10% owner

BAKER JULIAN · CIK 0001087939 · Director · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 1,154,580

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.

F2 · shares: On September 29, 2021, 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds") exercised warrants to purchase 11,184 and 138,815 shares of Common Stock of the Issuer, respectively, for $0.01 per share ("Prefunded Warrants"). 667 and Life Sciences paid the exercise price on a cashless basis, resulting in the Issuer withholding 2 and 14 shares of Common Stock for 667 and Life Sciences, respectively, of the Prefunded Warrant shares to pay the exercise price and issuing to 667 and Life Sciences the remaining 11,182 and 138,801 shares of Common Stock, respectively. The Issuer also paid $4.50 and $1.95 to 667 and Life Sciences, respectively, in cash in lieu of fractional shares. The Issuer's Board of Directors approved the exercise of the Prefunded Warrants by 667 and Life Sciences on the cashless basis described in this footnote in advance of such exercise.

F2 · price: On September 29, 2021, 667 and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds") exercised warrants to purchase 11,184 and 138,815 shares of Common Stock of the Issuer, respectively, for $0.01 per share ("Prefunded Warrants"). 667 and Life Sciences paid the exercise price on a cashless basis, resulting in the Issuer withholding 2 and 14 shares of Common Stock for 667 and Life Sciences, respectively, of the Prefunded Warrant shares to pay the exercise price and issuing to 667 and Life Sciences the remaining 11,182 and 138,801 shares of Common Stock, respectively. The Issuer also paid $4.50 and $1.95 to 667 and Life Sciences, respectively, in cash in lieu of fractional shares. The Issuer's Board of Directors approved the exercise of the Prefunded Warrants by 667 and Life Sciences on the cashless basis described in this footnote in advance of such exercise.

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 Kodiak Sciences Inc. (the "Issuer") reported in column 5 of Table I directly held by 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.

F4 · 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 by 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 by 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 by the Funds.

F5 · 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 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.

SEC source: 0001209191-21-057278 · doc4.xml · derivative · entry 5

EHRLICH JASON · CIK 0001754049 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 246,338

Underlying: Common Stock · 6,950 shares

Expires 2028-08-29

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.

F5 · derivative.exercise_date: Twenty-five percent of the shares subject to the option vested on September 1, 2019, and 1/48th of the shares subject to the option vest on the same day of each month thereafter.

SEC source: 0001209191-21-057278 · doc4.xml · nonDerivative · entry 4

EHRLICH JASON · CIK 0001754049 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 51,541

F1 · kind: The sales reported in this Form 4 were effected pursuant to a 10b5-1 trading plan.

F4 · price: The price reported in Column 4 is a weighted-average price. The shares were sold in multiple transactions ranging from $101.175 to $101.94, inclusive.

SEC source: 0001209191-21-057278 · doc4.xml · nonDerivative · entry 3

EHRLICH JASON · CIK 0001754049 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 51,890

F1 · kind: The sales reported in this Form 4 were effected pursuant to a 10b5-1 trading plan.

F3 · price: The price reported in Column 4 is a weighted-average price. The shares were sold in multiple transactions ranging from $100.14 to $100.96, inclusive.

SEC source: 0001209191-21-057278 · doc4.xml · nonDerivative · entry 2

EHRLICH JASON · CIK 0001754049 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 52,393

F1 · kind: The sales reported in this Form 4 were effected pursuant to a 10b5-1 trading plan.

F2 · price: The price reported in Column 4 is a weighted-average price. The shares were sold in multiple transactions ranging from $99.095 to $100.08, inclusive. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer, or the Staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in these footnotes.