Bain Capital Life Sciences Partners, LP

SEC source: 0001193125-26-237016 · ownership.xml · derivative · entry 4

Bain Capital Life Sciences Investors, LLC · CIK 0001703031 · 10% owner

Bain Capital Life Sciences Partners, LP · CIK 0001703030 · 10% owner

Bain Capital Life Sciences Fund, L.P. · CIK 0001687968 · 10% owner

BCIP Life Sciences Associates, LP · CIK 0001702921 · 10% owner

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: 1,463,000

Underlying: Class A Common Stock · 1,463,000 shares

Expires 2031-05-20

F1 · kind: On May 20, 2026, BCLS I Investco, LP ("BCLS I Investco") purchased, in an underwritten public offering, a Pre-Funded Warrant to purchase 1,463,000 shares of the Issuer's Class A Common Stock, as well as an accompanying Series A Warrant to purchase 1,463,000 shares of the Issuer's Class A Common Stock (or pre-funded warrants in lieu thereof) and an accompanying Series B Warrant to purchase 1,463,000 shares of the Issuer's Class A Common Stock (or pre-funded warrants in lieu thereof). The purchase price of each pre-funded warrant and accompanying Series A Warrant and Series B Warrant was $1.945.

F1 · price: On May 20, 2026, BCLS I Investco, LP ("BCLS I Investco") purchased, in an underwritten public offering, a Pre-Funded Warrant to purchase 1,463,000 shares of the Issuer's Class A Common Stock, as well as an accompanying Series A Warrant to purchase 1,463,000 shares of the Issuer's Class A Common Stock (or pre-funded warrants in lieu thereof) and an accompanying Series B Warrant to purchase 1,463,000 shares of the Issuer's Class A Common Stock (or pre-funded warrants in lieu thereof). The purchase price of each pre-funded warrant and accompanying Series A Warrant and Series B Warrant was $1.945.

F2 · derivative.exercise_date: The Pre-Funded Warrant, Series A Warrant and Series B Warrant cannot be exercised for shares of the Issuer's Class A Common Stock if, as a result of such exercise, the holder, together with its affiliates and any other persons whose beneficial ownership would be aggregated for purposes of Section 13(d) of the Act, would beneficially own more than 9.99% of the total number of shares of the Issuer's Class A Common Stock then outstanding immediately following such exercise.

F2 · derivative.underlying_shares: The Pre-Funded Warrant, Series A Warrant and Series B Warrant cannot be exercised for shares of the Issuer's Class A Common Stock if, as a result of such exercise, the holder, together with its affiliates and any other persons whose beneficial ownership would be aggregated for purposes of Section 13(d) of the Act, would beneficially own more than 9.99% of the total number of shares of the Issuer's Class A Common Stock then outstanding immediately following such exercise.

F1 · ownership.nature: On May 20, 2026, BCLS I Investco, LP ("BCLS I Investco") purchased, in an underwritten public offering, a Pre-Funded Warrant to purchase 1,463,000 shares of the Issuer's Class A Common Stock, as well as an accompanying Series A Warrant to purchase 1,463,000 shares of the Issuer's Class A Common Stock (or pre-funded warrants in lieu thereof) and an accompanying Series B Warrant to purchase 1,463,000 shares of the Issuer's Class A Common Stock (or pre-funded warrants in lieu thereof). The purchase price of each pre-funded warrant and accompanying Series A Warrant and Series B Warrant was $1.945.

F6 · ownership.nature: Bain Capital Life Sciences Investors, LLC ("BCLSI") is the general partner of each of BCLSP and BCLS I Investco and governs the investment strategy and decision-making process with respect to investments held by BCIPLS. As a result, BCLSI may be deemed to share voting and dispositive power with respect to the securities held by the Bain Capital Life Sciences Entities. BCLSI disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

SEC source: 0001193125-26-237016 · ownership.xml · derivative · entry 3

Bain Capital Life Sciences Investors, LLC · CIK 0001703031 · 10% owner

Bain Capital Life Sciences Partners, LP · CIK 0001703030 · 10% owner

Bain Capital Life Sciences Fund, L.P. · CIK 0001687968 · 10% owner

BCIP Life Sciences Associates, LP · CIK 0001702921 · 10% owner

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: 1,463,000

Underlying: Class A Common Stock · 1,463,000 shares

Expires 2027-05-20

F1 · kind: On May 20, 2026, BCLS I Investco, LP ("BCLS I Investco") purchased, in an underwritten public offering, a Pre-Funded Warrant to purchase 1,463,000 shares of the Issuer's Class A Common Stock, as well as an accompanying Series A Warrant to purchase 1,463,000 shares of the Issuer's Class A Common Stock (or pre-funded warrants in lieu thereof) and an accompanying Series B Warrant to purchase 1,463,000 shares of the Issuer's Class A Common Stock (or pre-funded warrants in lieu thereof). The purchase price of each pre-funded warrant and accompanying Series A Warrant and Series B Warrant was $1.945.

F1 · price: On May 20, 2026, BCLS I Investco, LP ("BCLS I Investco") purchased, in an underwritten public offering, a Pre-Funded Warrant to purchase 1,463,000 shares of the Issuer's Class A Common Stock, as well as an accompanying Series A Warrant to purchase 1,463,000 shares of the Issuer's Class A Common Stock (or pre-funded warrants in lieu thereof) and an accompanying Series B Warrant to purchase 1,463,000 shares of the Issuer's Class A Common Stock (or pre-funded warrants in lieu thereof). The purchase price of each pre-funded warrant and accompanying Series A Warrant and Series B Warrant was $1.945.

F2 · derivative.exercise_date: The Pre-Funded Warrant, Series A Warrant and Series B Warrant cannot be exercised for shares of the Issuer's Class A Common Stock if, as a result of such exercise, the holder, together with its affiliates and any other persons whose beneficial ownership would be aggregated for purposes of Section 13(d) of the Act, would beneficially own more than 9.99% of the total number of shares of the Issuer's Class A Common Stock then outstanding immediately following such exercise.

F2 · derivative.underlying_shares: The Pre-Funded Warrant, Series A Warrant and Series B Warrant cannot be exercised for shares of the Issuer's Class A Common Stock if, as a result of such exercise, the holder, together with its affiliates and any other persons whose beneficial ownership would be aggregated for purposes of Section 13(d) of the Act, would beneficially own more than 9.99% of the total number of shares of the Issuer's Class A Common Stock then outstanding immediately following such exercise.

F1 · ownership.nature: On May 20, 2026, BCLS I Investco, LP ("BCLS I Investco") purchased, in an underwritten public offering, a Pre-Funded Warrant to purchase 1,463,000 shares of the Issuer's Class A Common Stock, as well as an accompanying Series A Warrant to purchase 1,463,000 shares of the Issuer's Class A Common Stock (or pre-funded warrants in lieu thereof) and an accompanying Series B Warrant to purchase 1,463,000 shares of the Issuer's Class A Common Stock (or pre-funded warrants in lieu thereof). The purchase price of each pre-funded warrant and accompanying Series A Warrant and Series B Warrant was $1.945.

F6 · ownership.nature: Bain Capital Life Sciences Investors, LLC ("BCLSI") is the general partner of each of BCLSP and BCLS I Investco and governs the investment strategy and decision-making process with respect to investments held by BCIPLS. As a result, BCLSI may be deemed to share voting and dispositive power with respect to the securities held by the Bain Capital Life Sciences Entities. BCLSI disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

SEC source: 0001193125-26-237016 · ownership.xml · derivative · entry 2

Bain Capital Life Sciences Investors, LLC · CIK 0001703031 · 10% owner

Bain Capital Life Sciences Partners, LP · CIK 0001703030 · 10% owner

Bain Capital Life Sciences Fund, L.P. · CIK 0001687968 · 10% owner

BCIP Life Sciences Associates, LP · CIK 0001702921 · 10% owner

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: 1,463,000

Underlying: Class A Common Stock · 1,463,000 shares

Expires not disclosed

F1 · kind: On May 20, 2026, BCLS I Investco, LP ("BCLS I Investco") purchased, in an underwritten public offering, a Pre-Funded Warrant to purchase 1,463,000 shares of the Issuer's Class A Common Stock, as well as an accompanying Series A Warrant to purchase 1,463,000 shares of the Issuer's Class A Common Stock (or pre-funded warrants in lieu thereof) and an accompanying Series B Warrant to purchase 1,463,000 shares of the Issuer's Class A Common Stock (or pre-funded warrants in lieu thereof). The purchase price of each pre-funded warrant and accompanying Series A Warrant and Series B Warrant was $1.945.

F1 · price: On May 20, 2026, BCLS I Investco, LP ("BCLS I Investco") purchased, in an underwritten public offering, a Pre-Funded Warrant to purchase 1,463,000 shares of the Issuer's Class A Common Stock, as well as an accompanying Series A Warrant to purchase 1,463,000 shares of the Issuer's Class A Common Stock (or pre-funded warrants in lieu thereof) and an accompanying Series B Warrant to purchase 1,463,000 shares of the Issuer's Class A Common Stock (or pre-funded warrants in lieu thereof). The purchase price of each pre-funded warrant and accompanying Series A Warrant and Series B Warrant was $1.945.

F2 · derivative.exercise_date: The Pre-Funded Warrant, Series A Warrant and Series B Warrant cannot be exercised for shares of the Issuer's Class A Common Stock if, as a result of such exercise, the holder, together with its affiliates and any other persons whose beneficial ownership would be aggregated for purposes of Section 13(d) of the Act, would beneficially own more than 9.99% of the total number of shares of the Issuer's Class A Common Stock then outstanding immediately following such exercise.

F3 · derivative.expiration_date: The Pre-Funded Warrant does not expire.

F2 · derivative.underlying_shares: The Pre-Funded Warrant, Series A Warrant and Series B Warrant cannot be exercised for shares of the Issuer's Class A Common Stock if, as a result of such exercise, the holder, together with its affiliates and any other persons whose beneficial ownership would be aggregated for purposes of Section 13(d) of the Act, would beneficially own more than 9.99% of the total number of shares of the Issuer's Class A Common Stock then outstanding immediately following such exercise.

F1 · ownership.nature: On May 20, 2026, BCLS I Investco, LP ("BCLS I Investco") purchased, in an underwritten public offering, a Pre-Funded Warrant to purchase 1,463,000 shares of the Issuer's Class A Common Stock, as well as an accompanying Series A Warrant to purchase 1,463,000 shares of the Issuer's Class A Common Stock (or pre-funded warrants in lieu thereof) and an accompanying Series B Warrant to purchase 1,463,000 shares of the Issuer's Class A Common Stock (or pre-funded warrants in lieu thereof). The purchase price of each pre-funded warrant and accompanying Series A Warrant and Series B Warrant was $1.945.

F6 · ownership.nature: Bain Capital Life Sciences Investors, LLC ("BCLSI") is the general partner of each of BCLSP and BCLS I Investco and governs the investment strategy and decision-making process with respect to investments held by BCIPLS. As a result, BCLSI may be deemed to share voting and dispositive power with respect to the securities held by the Bain Capital Life Sciences Entities. BCLSI disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

SEC source: 0000950170-25-025011 · ownership.xml · derivative · entry 2

Bain Capital Life Sciences Investors, LLC · CIK 0001703031 · 10% owner

BCLS SB Investco, LP · CIK 0001728056 · 10% owner

Bain Capital Life Sciences Partners, LP · CIK 0001703030 · 10% owner

Bain Capital Life Sciences Fund II, L.P. · CIK 0001773187 · 10% owner

Bain Capital Life Sciences Investors II, LLC · CIK 0001796155 · 10% owner

BCLS II Investco, LP · CIK 0001818893 · 10% owner

BCLS II Investco (GP), LLC · CIK 0001819101 · 10% owner

BCIP Life Sciences Associates, LP · CIK 0001702921 · 10% owner

BCLS II Equity Opportunities, LP · CIK 0001814474 · 10% owner

BCLS II Equity Opportunities GP, LLC · CIK 0002008174 · 10% owner

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: 6,444,170

Underlying: Common Stock · 6,444,170 shares

Expires not disclosed

F1 · kind: On February 19, 2025, BCLS II Investco, LP ("BCLS II Investco") purchased 1,000,000 shares of the Issuer's common stock and a pre-funded warrant to purchase 6,444,170 shares of the Issuer's common stock at a purchase price of $4.03 and $4.029, respectively, in an underwritten public offering (the "February 2025 Underwritten Offering").

F2 · derivative.exercise_date: The pre-funded warrant cannot be exercised if, as a result of such exercise, the holder, together with its affiliates and any other persons whose beneficial ownership would be aggregated with the holder for purposes of Section 13(d) of the Act, would beneficially own more than 9.99% of the total number of shares of the Issuer's common stock then outstanding immediately following such exercise.

F3 · derivative.expiration_date: The pre-funded warrant does not expire.

F2 · derivative.underlying_shares: The pre-funded warrant cannot be exercised if, as a result of such exercise, the holder, together with its affiliates and any other persons whose beneficial ownership would be aggregated with the holder for purposes of Section 13(d) of the Act, would beneficially own more than 9.99% of the total number of shares of the Issuer's common stock then outstanding immediately following such exercise.

F5 · ownership.nature: Represents a pre-funded warrant to purchase 6,444,170 shares of the Issuer's common stock held directly by BCLS II Investco, after giving effect to the closing of the February 2025 Underwritten Offering.

F8 · ownership.nature: BCLS II Investco (GP), LLC ("BCLS II Investco GP"), whose managing member is BCLS Fund II, is the general partner of BCLS II Investco. As a result, each of BCLSI II, BCLS Fund II and BCLS II Investco GP may be deemed to share voting and dispositive power with respect to the securities held by BCLS II Investco. Each of BCLSI II, BCLS Fund II and BCLS II Investco GP disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F11 · ownership.nature: Bain Capital Life Sciences Investors, LLC ("BCLSI") (i) is the general partner of BCLSP, (ii) is the manager of BCLSI II and (iii) governs the investment strategy and decision-making process with respect to investments held by BCIPLS. As a result, BCLSI may be deemed to share voting and dispositive power with respect to the securities held by the Bain Capital Life Sciences Entities. BCLSI disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

SEC source: 0000950170-25-025011 · ownership.xml · nonDerivative · entry 1

Bain Capital Life Sciences Investors, LLC · CIK 0001703031 · 10% owner

BCLS SB Investco, LP · CIK 0001728056 · 10% owner

Bain Capital Life Sciences Partners, LP · CIK 0001703030 · 10% owner

Bain Capital Life Sciences Fund II, L.P. · CIK 0001773187 · 10% owner

Bain Capital Life Sciences Investors II, LLC · CIK 0001796155 · 10% owner

BCLS II Investco, LP · CIK 0001818893 · 10% owner

BCLS II Investco (GP), LLC · CIK 0001819101 · 10% owner

BCIP Life Sciences Associates, LP · CIK 0001702921 · 10% owner

BCLS II Equity Opportunities, LP · CIK 0001814474 · 10% owner

BCLS II Equity Opportunities GP, LLC · CIK 0002008174 · 10% owner

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: 5,034,582

F1 · kind: On February 19, 2025, BCLS II Investco, LP ("BCLS II Investco") purchased 1,000,000 shares of the Issuer's common stock and a pre-funded warrant to purchase 6,444,170 shares of the Issuer's common stock at a purchase price of $4.03 and $4.029, respectively, in an underwritten public offering (the "February 2025 Underwritten Offering").

F4 · ownership.nature: Represents 528,660 shares of the Issuer's common stock held directly by BCLS SB Investco, LP ("BCLS SB"), 267,257 shares of the Issuer's common stock held directly by Bain Capital Life Sciences Fund II, L.P. ("BCLS Fund II"), 3,301,955 shares of the Issuer's common stock held directly by BCLS II Investco, 904,160 shares of the Issuer's common stock held directly by BCLS II Equity Opportunities, LP ("BCLS II Equity") and 32,550 shares of the Issuer's common stock held directly by BCIP Life Sciences Associates, LP ("BCIPLS" and, together with BCLS II Investco, BCLS SB, BCLS Fund II and BCLS II Equity, the "Bain Capital Life Sciences Entities"), after giving effect to the closing of the February 2025 Underwritten Offering.

F6 · ownership.nature: Bain Capital Life Sciences Partners, LP ("BCLSP") is the general partner of BCLS SB. As a result, BCLSP may be deemed to share voting and dispositive power with respect to the securities held by BCLS SB. BCLSP disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F7 · ownership.nature: Bain Capital Life Sciences Investors II, LLC ("BCLSI II") is the general partner of BCLS Fund II. As a result, BCLSI II may be deemed to share voting and dispositive power with respect to the securities held by BCLS Fund II. BCLSI II disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F8 · ownership.nature: BCLS II Investco (GP), LLC ("BCLS II Investco GP"), whose managing member is BCLS Fund II, is the general partner of BCLS II Investco. As a result, each of BCLSI II, BCLS Fund II and BCLS II Investco GP may be deemed to share voting and dispositive power with respect to the securities held by BCLS II Investco. Each of BCLSI II, BCLS Fund II and BCLS II Investco GP disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F9 · ownership.nature: BCLS II Equity Opportunities GP, LLC ("BCLS II Equity GP"), whose manager is BCLS Fund II, is the general partner of BCLS II Equity. As a result, each of BCLSI II, BCLS Fund II and BCLS II Equity GP may be deemed to share voting and dispositive power with respect to the securities held by BCLS II Equity. Each of BCLSI II, BCLS Fund II and BCLS II Equity GP disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F10 · ownership.nature: Boylston Coinvestors, LLC is the general partner of BCIPLS.

F11 · ownership.nature: Bain Capital Life Sciences Investors, LLC ("BCLSI") (i) is the general partner of BCLSP, (ii) is the manager of BCLSI II and (iii) governs the investment strategy and decision-making process with respect to investments held by BCIPLS. As a result, BCLSI may be deemed to share voting and dispositive power with respect to the securities held by the Bain Capital Life Sciences Entities. BCLSI disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

SEC source: 0000950170-24-004289 · ownership.xml · nonDerivative · entry 1

Bain Capital Life Sciences Investors, LLC · CIK 0001703031 · Director · 10% owner

BCLS SB Investco, LP · CIK 0001728056 · Director · 10% owner

Bain Capital Life Sciences Partners, LP · CIK 0001703030 · Director · 10% owner

Bain Capital Life Sciences Fund II, L.P. · CIK 0001773187 · Director · 10% owner

Bain Capital Life Sciences Investors II, LLC · CIK 0001796155 · Director · 10% owner

BCLS II Investco, LP · CIK 0001818893 · Director · 10% owner

BCLS II Investco (GP), LLC · CIK 0001819101 · Director · 10% owner

BCIP Life Sciences Associates, LP · CIK 0001702921 · Director · 10% owner

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: 4,034,582

F1 · kind: On January 8, 2024, BCLS II Equity Opportunities, LP ("BCLS II Equity") entered into a securities purchase agreement with the Issuer pursuant to which the Issuer agreed to issue and sell 904,160 shares of Common Stock to BCLS II Equity at a price of $5.53 per share (the "January 2024 Private Placement"). The January 2024 Private Placement closed on January 11, 2024. BCLS II Equity and BCLS II Equity Opportunities GP, LLC ("BCLS II Equity GP"), its general partner, plan to file a Form 3 with the Securities and Exchange Commission in connection with the acquisition of shares of Common Stock by BCLS II Equity in the January 2024 Private Placement.

F2 · ownership.nature: Represents 528,660 shares of Common Stock held directly by BCLS SB Investco, LP ("BCLS SB"), 267,257 shares of Common Stock held directly by Bain Capital Life Sciences Fund II, L.P. ("BCLS Fund II"), 2,301,955 shares of Common Stock held directly by BCLS II Investco, LP ("BCLS II Investco"), 904,160 shares of Common Stock held directly by BCLS II Equity and 32,550 shares of Common Stock held directly by BCIP Life Sciences Associates, LP ("BCIPLS" and, together with BCLS SB, BCLS Fund II, BCLS II Investco and BCLS II Equity, the "Bain Capital Life Sciences Entities"), after giving effect to the closing of the January 2024 Private Placement.

F3 · ownership.nature: Bain Capital Life Sciences Partners, LP ("BCLSP") is the general partner of BCLS SB. As a result, BCLSP may be deemed to share voting and dispositive power with respect to the securities held by BCLS SB. BCLSP disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F4 · ownership.nature: Bain Capital Life Sciences Investors II, LLC ("BCLSI II") is the general partner of BCLS Fund II. As a result, BCLSI II may be deemed to share voting and dispositive power with respect to the securities held by BCLS Fund II. BCLSI II disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F5 · ownership.nature: BCLS II Investco (GP), LLC ("BCLS II Investco GP"), whose managing member is BCLS Fund II, is the general partner of BCLS II Investco. As a result, each of BCLSI II, BCLS Fund II and BCLS II Investco GP may be deemed to share voting and dispositive power with respect to the securities held by BCLS II Investco. Each of BCLSI II, BCLS Fund II and BCLS II Investco GP disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F6 · ownership.nature: BCLS Fund II is the manager of BCLS II Equity GP. As a result, each of BCLSI II and BCLS Fund II may be deemed to share voting and dispositive power with respect to the securities held by BCLS II Equity. Each of BCLSI II and BCLS Fund II disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F7 · ownership.nature: Boylston Coinvestors, LLC is the general partner of BCIPLS.

F8 · ownership.nature: Bain Capital Life Sciences Investors, LLC ("BCLSI") (i) is the general partner of BCLSP, (ii) is the manager of BCLSI II and (iii) governs the investment strategy and decision-making process with respect to investments held by BCIPLS. As a result, BCLSI may be deemed to share voting and dispositive power with respect to the securities held by the Bain Capital Life Sciences Entities. BCLSI disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

SEC source: 0000899243-23-014139 · doc4.xml · nonDerivative · entry 1

Bain Capital Life Sciences Investors, LLC · CIK 0001703031 · 10% owner

Bain Capital Life Sciences Fund, L.P. · CIK 0001687968 · 10% owner

Bain Capital Life Sciences Partners, LP · CIK 0001703030 · 10% owner

BCIP Life Sciences Associates, LP · CIK 0001702921 · 10% owner

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: 5,701,926

F1 · shares: Represents 300,000 shares of Common Stock purchased by BCLS I Investco, LP ("BCLS I Investco") on May 25, 2023.

F2 · price: The price reported in Column 4 is a weighted average price. The shares were purchased in multiple transactions at prices ranging from $2.08 to $2.25, inclusive. The reporting persons undertake to provide to the Issuer, any securityholder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth herein.

F3 · ownership.nature: Represents shares of Common Stock held by Bain Capital Life Sciences Fund, L.P. ("BCLS Fund I"), BCLS I Investco and BCIP Life Sciences Associates, LP ("BCIPLS" and, together with BCLS Fund I and BCLS I Investco, the "Bain Capital Life Sciences Entities"). Following the completion of the transactions reported in footnote (1) above, BCLS Fund I, BCLS I Investco and BCIPLS each holds 2,940,627, 2,460,298 and 301,001 shares of Common Stock, respectively.

F4 · ownership.nature: Bain Capital Life Sciences Partners, LP ("BCLSP") is the general partner of BCLS Fund I. As a result, BCLSP may be deemed to share voting and dispositive power with respect to the securities held by BCLS Fund I. BCLSP disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F5 · ownership.nature: BCLS I Investco GP, LLC ("BCLS I Investco GP"), whose manager is BCLS Fund I, is the general partner of BCLS I Investco. As a result, each of BCLSP, BCLS Fund I and BCLS I Investco GP may be deemed to share voting and dispositive power with respect to the securities held by BCLS I Investco. Each of BCLSP, BCLS Fund I and BCLS I Investco GP disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F6 · ownership.nature: Boylston Coinvestors, LLC is the general partner of BCIPLS.

F7 · ownership.nature: Bain Capital Life Sciences Investors, LLC ("BCLSI") is the general partner of BCLSP and governs the investment strategy and decision making process with respect to investments held by BCIPLS. As a result, BCLSI may be deemed to share voting and dispositive power with respect to the securities held by the Bain Capital Life Sciences Entities. BCLSI disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

SEC source: 0000899243-21-029222 · doc4.xml · derivative · entry 5

Bain Capital Life Sciences Investors, LLC · CIK 0001703031 · 10% owner

Bain Capital Life Sciences Partners, LP · CIK 0001703030 · 10% owner

Bain Capital Life Sciences Fund, L.P. · CIK 0001687968 · 10% owner

BCIP Life Sciences Associates, LP · CIK 0001702921 · 10% owner

Schwartz Jeffrey Lawrence · CIK 0001702957 · Director · 10% owner

Koppel Adam · CIK 0001578965 · 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: Class A Common Stock · 1,334,562 shares

Expires not disclosed

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_price: Each share of the Issuer's Series B1 Preferred Stock and Series C1 Preferred Stock automatically converted into 0.2 of a share of the Issuer's Class A Common Stock immediately prior to the closing of the Issuer's initial public offering.

F1 · price: Each share of the Issuer's Series B1 Preferred Stock and Series C1 Preferred Stock automatically converted into 0.2 of a share of the Issuer's Class A Common Stock immediately prior to the closing of the Issuer's initial public offering.

F1 · derivative.exercise_date: Each share of the Issuer's Series B1 Preferred Stock and Series C1 Preferred Stock automatically converted into 0.2 of a share of the Issuer's Class A Common Stock immediately prior to the closing of the Issuer's initial public offering.

F1 · derivative.expiration_date: Each share of the Issuer's Series B1 Preferred Stock and Series C1 Preferred Stock automatically converted into 0.2 of a share of the Issuer's Class A Common Stock immediately prior to the closing of the Issuer's initial public offering.

F3 · ownership.nature: Represents 6,053,214 shares of the Issuer's Series C1 Preferred Stock held by BCLS and 619,605 shares of the Issuer's Series C1 Preferred Stock held by BCIPLS, which were automatically converted into 1,210,642 and 123,920 shares of the Issuer's Class A Common stock, respectively, immediately prior to the closing of the Issuer's initial public offering.

F5 · ownership.nature: Bain Capital Life Sciences Partners, LP ("BCLSP") is the general partner of BCLS. As a result, BCLSP may be deemed to share voting and dispositive power with respect to the securities held by BCLS. BCLSP disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F6 · ownership.nature: Bain Capital Life Sciences Investors, LLC ("BCLSI"), whose managers are Jeffrey Schwartz and Adam Koppel, is the general partner of BCLSP and governs the investment strategy and decision-making process with respect to investments held by BCIPLS, whose general partner is Boylston Coinvestors, LLC. As a result, each of BCLSI, Mr. Schwartz and Dr. Koppel may be deemed to share voting and dispositive power with respect to the securities held by the Bain Capital Life Sciences Entities. BCLSI, Mr. Schwartz and Dr. Koppel each disclaim beneficial ownership of such securities except to the extent of its or their pecuniary interest therein.

F7 · ownership.nature: Jeffrey Schwartz is a director of the Issuer.

SEC source: 0000899243-21-029222 · doc4.xml · derivative · entry 4

Bain Capital Life Sciences Investors, LLC · CIK 0001703031 · 10% owner

Bain Capital Life Sciences Partners, LP · CIK 0001703030 · 10% owner

Bain Capital Life Sciences Fund, L.P. · CIK 0001687968 · 10% owner

BCIP Life Sciences Associates, LP · CIK 0001702921 · 10% owner

Schwartz Jeffrey Lawrence · CIK 0001702957 · Director · 10% owner

Koppel Adam · CIK 0001578965 · 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: Class A Common Stock · 6,999,998 shares

Expires not disclosed

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_price: Each share of the Issuer's Series B1 Preferred Stock and Series C1 Preferred Stock automatically converted into 0.2 of a share of the Issuer's Class A Common Stock immediately prior to the closing of the Issuer's initial public offering.

F1 · price: Each share of the Issuer's Series B1 Preferred Stock and Series C1 Preferred Stock automatically converted into 0.2 of a share of the Issuer's Class A Common Stock immediately prior to the closing of the Issuer's initial public offering.

F1 · derivative.exercise_date: Each share of the Issuer's Series B1 Preferred Stock and Series C1 Preferred Stock automatically converted into 0.2 of a share of the Issuer's Class A Common Stock immediately prior to the closing of the Issuer's initial public offering.

F1 · derivative.expiration_date: Each share of the Issuer's Series B1 Preferred Stock and Series C1 Preferred Stock automatically converted into 0.2 of a share of the Issuer's Class A Common Stock immediately prior to the closing of the Issuer's initial public offering.

F2 · ownership.nature: Represents 31,750,072 shares of the Issuer's Series B1 Preferred Stock held by Bain Capital Life Sciences Fund, L.P. ("BCLS") and 3,249,929 shares of the Issuer's Series B1 Preferred Stock held by BCIP Life Sciences Associates, LP ("BCIPLS" and, together with BCLS, the "Bain Capital Life Sciences Entities"), which were automatically converted into 6,350,013 and 649,985 shares of the Issuer's Class A Common Stock, respectively, immediately prior to the closing of the Issuer's initial public offering.

F5 · ownership.nature: Bain Capital Life Sciences Partners, LP ("BCLSP") is the general partner of BCLS. As a result, BCLSP may be deemed to share voting and dispositive power with respect to the securities held by BCLS. BCLSP disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F6 · ownership.nature: Bain Capital Life Sciences Investors, LLC ("BCLSI"), whose managers are Jeffrey Schwartz and Adam Koppel, is the general partner of BCLSP and governs the investment strategy and decision-making process with respect to investments held by BCIPLS, whose general partner is Boylston Coinvestors, LLC. As a result, each of BCLSI, Mr. Schwartz and Dr. Koppel may be deemed to share voting and dispositive power with respect to the securities held by the Bain Capital Life Sciences Entities. BCLSI, Mr. Schwartz and Dr. Koppel each disclaim beneficial ownership of such securities except to the extent of its or their pecuniary interest therein.

F7 · ownership.nature: Jeffrey Schwartz is a director of the Issuer.

SEC source: 0000899243-21-029222 · doc4.xml · nonDerivative · entry 3

Bain Capital Life Sciences Investors, LLC · CIK 0001703031 · 10% owner

Bain Capital Life Sciences Partners, LP · CIK 0001703030 · 10% owner

Bain Capital Life Sciences Fund, L.P. · CIK 0001687968 · 10% owner

BCIP Life Sciences Associates, LP · CIK 0001702921 · 10% owner

Schwartz Jeffrey Lawrence · CIK 0001702957 · Director · 10% owner

Koppel Adam · CIK 0001578965 · 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: 8,434,560

F4 · ownership.nature: Represents 90,714 and 9,286 shares of the Issuer's Class A Common Stock purchased by BCLS and BCIPLS, respectively, in the Issuer's initial public offering.

F5 · ownership.nature: Bain Capital Life Sciences Partners, LP ("BCLSP") is the general partner of BCLS. As a result, BCLSP may be deemed to share voting and dispositive power with respect to the securities held by BCLS. BCLSP disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F6 · ownership.nature: Bain Capital Life Sciences Investors, LLC ("BCLSI"), whose managers are Jeffrey Schwartz and Adam Koppel, is the general partner of BCLSP and governs the investment strategy and decision-making process with respect to investments held by BCIPLS, whose general partner is Boylston Coinvestors, LLC. As a result, each of BCLSI, Mr. Schwartz and Dr. Koppel may be deemed to share voting and dispositive power with respect to the securities held by the Bain Capital Life Sciences Entities. BCLSI, Mr. Schwartz and Dr. Koppel each disclaim beneficial ownership of such securities except to the extent of its or their pecuniary interest therein.

F7 · ownership.nature: Jeffrey Schwartz is a director of the Issuer.

SEC source: 0000899243-21-029222 · doc4.xml · nonDerivative · entry 2

Bain Capital Life Sciences Investors, LLC · CIK 0001703031 · 10% owner

Bain Capital Life Sciences Partners, LP · CIK 0001703030 · 10% owner

Bain Capital Life Sciences Fund, L.P. · CIK 0001687968 · 10% owner

BCIP Life Sciences Associates, LP · CIK 0001702921 · 10% owner

Schwartz Jeffrey Lawrence · CIK 0001702957 · Director · 10% owner

Koppel Adam · CIK 0001578965 · 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: 8,334,560

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 · price: Each share of the Issuer's Series B1 Preferred Stock and Series C1 Preferred Stock automatically converted into 0.2 of a share of the Issuer's Class A Common Stock immediately prior to the closing of the Issuer's initial public offering.

F3 · ownership.nature: Represents 6,053,214 shares of the Issuer's Series C1 Preferred Stock held by BCLS and 619,605 shares of the Issuer's Series C1 Preferred Stock held by BCIPLS, which were automatically converted into 1,210,642 and 123,920 shares of the Issuer's Class A Common stock, respectively, immediately prior to the closing of the Issuer's initial public offering.

F5 · ownership.nature: Bain Capital Life Sciences Partners, LP ("BCLSP") is the general partner of BCLS. As a result, BCLSP may be deemed to share voting and dispositive power with respect to the securities held by BCLS. BCLSP disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F6 · ownership.nature: Bain Capital Life Sciences Investors, LLC ("BCLSI"), whose managers are Jeffrey Schwartz and Adam Koppel, is the general partner of BCLSP and governs the investment strategy and decision-making process with respect to investments held by BCIPLS, whose general partner is Boylston Coinvestors, LLC. As a result, each of BCLSI, Mr. Schwartz and Dr. Koppel may be deemed to share voting and dispositive power with respect to the securities held by the Bain Capital Life Sciences Entities. BCLSI, Mr. Schwartz and Dr. Koppel each disclaim beneficial ownership of such securities except to the extent of its or their pecuniary interest therein.

F7 · ownership.nature: Jeffrey Schwartz is a director of the Issuer.

SEC source: 0000899243-21-029222 · doc4.xml · nonDerivative · entry 1

Bain Capital Life Sciences Investors, LLC · CIK 0001703031 · 10% owner

Bain Capital Life Sciences Partners, LP · CIK 0001703030 · 10% owner

Bain Capital Life Sciences Fund, L.P. · CIK 0001687968 · 10% owner

BCIP Life Sciences Associates, LP · CIK 0001702921 · 10% owner

Schwartz Jeffrey Lawrence · CIK 0001702957 · Director · 10% owner

Koppel Adam · CIK 0001578965 · 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: 6,999,998

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 · price: Each share of the Issuer's Series B1 Preferred Stock and Series C1 Preferred Stock automatically converted into 0.2 of a share of the Issuer's Class A Common Stock immediately prior to the closing of the Issuer's initial public offering.

F2 · ownership.nature: Represents 31,750,072 shares of the Issuer's Series B1 Preferred Stock held by Bain Capital Life Sciences Fund, L.P. ("BCLS") and 3,249,929 shares of the Issuer's Series B1 Preferred Stock held by BCIP Life Sciences Associates, LP ("BCIPLS" and, together with BCLS, the "Bain Capital Life Sciences Entities"), which were automatically converted into 6,350,013 and 649,985 shares of the Issuer's Class A Common Stock, respectively, immediately prior to the closing of the Issuer's initial public offering.

F5 · ownership.nature: Bain Capital Life Sciences Partners, LP ("BCLSP") is the general partner of BCLS. As a result, BCLSP may be deemed to share voting and dispositive power with respect to the securities held by BCLS. BCLSP disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F6 · ownership.nature: Bain Capital Life Sciences Investors, LLC ("BCLSI"), whose managers are Jeffrey Schwartz and Adam Koppel, is the general partner of BCLSP and governs the investment strategy and decision-making process with respect to investments held by BCIPLS, whose general partner is Boylston Coinvestors, LLC. As a result, each of BCLSI, Mr. Schwartz and Dr. Koppel may be deemed to share voting and dispositive power with respect to the securities held by the Bain Capital Life Sciences Entities. BCLSI, Mr. Schwartz and Dr. Koppel each disclaim beneficial ownership of such securities except to the extent of its or their pecuniary interest therein.

F7 · ownership.nature: Jeffrey Schwartz is a director of the Issuer.

SEC source: 0000899243-20-029321 · doc4.xml · nonDerivative · entry 1

Bain Capital Life Sciences Investors, LLC · CIK 0001703031 · 10% owner

Bain Capital Life Sciences Partners, LP · CIK 0001703030 · 10% owner

Bain Capital Life Sciences Fund, L.P. · CIK 0001687968 · 10% owner

BCIP Life Sciences Associates, LP · CIK 0001702921 · 10% owner

Schwartz Jeffrey Lawrence · CIK 0001702957 · 10% owner

Koppel Adam · CIK 0001578965 · 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: 8,891,758

F1 · kind: On October 26, 2020, Bain Capital Life Sciences Fund, L.P. ("BCLS") and BCIP Life Sciences Fund, LP ("BCIPLS and, together with BCLS, the "Bain Capital Life Sciences Entities") purchased an aggregate of 3,333,333 shares of Common Stock in an underwritten public offering at a price per share of $3.00. BCLS purchased 3,023,816 of such shares and BCIPLS purchased 309,517 of such shares. Following such purchases, BCLS holds 8,066,113 shares of Common Stock and BCIPLS holds 825,645 shares of Common Stock.

F2 · ownership.nature: Bain Capital Life Sciences Partners, LP ("BCLSP") is the general partner of BCLS. As a result, BCLSP may be deemed to share voting and dispositive power with respect to the shares of Common Stock held by BCLS. BCLSP disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F3 · ownership.nature: Bain Capital Life Sciences Investors, LLC ("BCLSI"), whose managers are Jeffrey Schwartz and Adam Koppel, is the general partner of BCLSP and governs the investment strategy and decision-making process with respect to investments held by BCIPLS, whose general partner is Boylston Coinvestors, LLC. As a result, each of BCLSI, Mr. Schwartz and Dr. Koppel may be deemed to share voting and dispositive power with respect to the shares of Common Stock held by the Bain Capital Life Sciences Entities. BCLSI, Mr. Schwartz and Dr. Koppel each disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein.

F4 · ownership.nature: Adam Koppel is a director of the Issuer.

SEC source: 0000899243-20-020554 · doc4.xml · derivative · entry 5

Bain Capital Life Sciences Investors, LLC · CIK 0001703031 · 10% owner

Bain Capital Life Sciences Fund, L.P. · CIK 0001687968 · 10% owner

BCIP Life Sciences Associates, LP · CIK 0001702921 · 10% owner

Koppel Adam · CIK 0001578965 · 10% owner

Bain Capital Life Sciences Partners, LP · CIK 0001703030 · 10% owner

Schwartz Jeffrey Lawrence · CIK 0001702957 · 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 · 319,243 shares

Expires not disclosed

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_price: Each share of Series C Preferred Stock ("Series C Stock") and Series D Preferred Stock ("Series D Stock") automatically converted on a 1-for-8.81 basis into the Issuer's Common Stock immediately prior to the closing of the Issuer's initial public offering.

F1 · price: Each share of Series C Preferred Stock ("Series C Stock") and Series D Preferred Stock ("Series D Stock") automatically converted on a 1-for-8.81 basis into the Issuer's Common Stock immediately prior to the closing of the Issuer's initial public offering.

F1 · derivative.exercise_date: Each share of Series C Preferred Stock ("Series C Stock") and Series D Preferred Stock ("Series D Stock") automatically converted on a 1-for-8.81 basis into the Issuer's Common Stock immediately prior to the closing of the Issuer's initial public offering.

F1 · derivative.expiration_date: Each share of Series C Preferred Stock ("Series C Stock") and Series D Preferred Stock ("Series D Stock") automatically converted on a 1-for-8.81 basis into the Issuer's Common Stock immediately prior to the closing of the Issuer's initial public offering.

F3 · ownership.nature: Represents 2,551,384 shares of Series D Stock held of record by BCLS and 261,159 shares of Series D Stock held of record by BCIPLS.

F5 · ownership.nature: Bain Capital Life Sciences Partners, LP ("BCLSP") is the general partner of BCLS. As a result, BCLSP may be deemed to share voting and dispositive power with respect to the securities held by BCLS. BCLSP disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F6 · ownership.nature: Bain Capital Life Sciences Investors, LLC ("BCLSI"), whose managers are Jeffrey Schwartz and Adam Koppel, is the general partner of BCLSP and governs the investment strategy and decision-making process with respect to investments held by BCIPLS, whose general partner is Boylston Coinvestors, LLC. As a result, each of BCLSI, Mr. Schwartz and Dr. Koppel may be deemed to share voting and dispositive power over the shares held by the Bain Capital Life Sciences Entities. BCLSI, Mr. Schwartz and Dr. Koppel each disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein.

SEC source: 0000899243-20-020554 · doc4.xml · derivative · entry 4

Bain Capital Life Sciences Investors, LLC · CIK 0001703031 · 10% owner

Bain Capital Life Sciences Fund, L.P. · CIK 0001687968 · 10% owner

BCIP Life Sciences Associates, LP · CIK 0001702921 · 10% owner

Koppel Adam · CIK 0001578965 · 10% owner

Bain Capital Life Sciences Partners, LP · CIK 0001703030 · 10% owner

Schwartz Jeffrey Lawrence · CIK 0001702957 · 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 · 2,522,385 shares

Expires not disclosed

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_price: Each share of Series C Preferred Stock ("Series C Stock") and Series D Preferred Stock ("Series D Stock") automatically converted on a 1-for-8.81 basis into the Issuer's Common Stock immediately prior to the closing of the Issuer's initial public offering.

F1 · price: Each share of Series C Preferred Stock ("Series C Stock") and Series D Preferred Stock ("Series D Stock") automatically converted on a 1-for-8.81 basis into the Issuer's Common Stock immediately prior to the closing of the Issuer's initial public offering.

F1 · derivative.exercise_date: Each share of Series C Preferred Stock ("Series C Stock") and Series D Preferred Stock ("Series D Stock") automatically converted on a 1-for-8.81 basis into the Issuer's Common Stock immediately prior to the closing of the Issuer's initial public offering.

F1 · derivative.expiration_date: Each share of Series C Preferred Stock ("Series C Stock") and Series D Preferred Stock ("Series D Stock") automatically converted on a 1-for-8.81 basis into the Issuer's Common Stock immediately prior to the closing of the Issuer's initial public offering.

F2 · ownership.nature: Represents 20,158,775 shares of Series C Stock held of record by Bain Capital Life Sciences Fund, L.P. ("BCLS") and 2,063,446 shares of Series C Stock held of record by BCIP Life Sciences Associates, LP ("BCIPLS" and, together with BCLS, the "Bain Capital Life Sciences Entities").

F5 · ownership.nature: Bain Capital Life Sciences Partners, LP ("BCLSP") is the general partner of BCLS. As a result, BCLSP may be deemed to share voting and dispositive power with respect to the securities held by BCLS. BCLSP disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F6 · ownership.nature: Bain Capital Life Sciences Investors, LLC ("BCLSI"), whose managers are Jeffrey Schwartz and Adam Koppel, is the general partner of BCLSP and governs the investment strategy and decision-making process with respect to investments held by BCIPLS, whose general partner is Boylston Coinvestors, LLC. As a result, each of BCLSI, Mr. Schwartz and Dr. Koppel may be deemed to share voting and dispositive power over the shares held by the Bain Capital Life Sciences Entities. BCLSI, Mr. Schwartz and Dr. Koppel each disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein.

SEC source: 0000899243-20-020554 · doc4.xml · nonDerivative · entry 3

Bain Capital Life Sciences Investors, LLC · CIK 0001703031 · 10% owner

Bain Capital Life Sciences Fund, L.P. · CIK 0001687968 · 10% owner

BCIP Life Sciences Associates, LP · CIK 0001702921 · 10% owner

Koppel Adam · CIK 0001578965 · 10% owner

Bain Capital Life Sciences Partners, LP · CIK 0001703030 · 10% owner

Schwartz Jeffrey Lawrence · CIK 0001702957 · 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: 3,241,628

F4 · ownership.nature: Represents 362,858 and 37,142 shares of the Issuer's Common Stock purchased by BCLS and BCIPLS, respectively, in the Issuer's initial public offering.

F5 · ownership.nature: Bain Capital Life Sciences Partners, LP ("BCLSP") is the general partner of BCLS. As a result, BCLSP may be deemed to share voting and dispositive power with respect to the securities held by BCLS. BCLSP disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F6 · ownership.nature: Bain Capital Life Sciences Investors, LLC ("BCLSI"), whose managers are Jeffrey Schwartz and Adam Koppel, is the general partner of BCLSP and governs the investment strategy and decision-making process with respect to investments held by BCIPLS, whose general partner is Boylston Coinvestors, LLC. As a result, each of BCLSI, Mr. Schwartz and Dr. Koppel may be deemed to share voting and dispositive power over the shares held by the Bain Capital Life Sciences Entities. BCLSI, Mr. Schwartz and Dr. Koppel each disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein.

SEC source: 0000899243-20-020554 · doc4.xml · nonDerivative · entry 2

Bain Capital Life Sciences Investors, LLC · CIK 0001703031 · 10% owner

Bain Capital Life Sciences Fund, L.P. · CIK 0001687968 · 10% owner

BCIP Life Sciences Associates, LP · CIK 0001702921 · 10% owner

Koppel Adam · CIK 0001578965 · 10% owner

Bain Capital Life Sciences Partners, LP · CIK 0001703030 · 10% owner

Schwartz Jeffrey Lawrence · CIK 0001702957 · 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: 2,841,628

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 · price: Each share of Series C Preferred Stock ("Series C Stock") and Series D Preferred Stock ("Series D Stock") automatically converted on a 1-for-8.81 basis into the Issuer's Common Stock immediately prior to the closing of the Issuer's initial public offering.

F3 · ownership.nature: Represents 2,551,384 shares of Series D Stock held of record by BCLS and 261,159 shares of Series D Stock held of record by BCIPLS.

F5 · ownership.nature: Bain Capital Life Sciences Partners, LP ("BCLSP") is the general partner of BCLS. As a result, BCLSP may be deemed to share voting and dispositive power with respect to the securities held by BCLS. BCLSP disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F6 · ownership.nature: Bain Capital Life Sciences Investors, LLC ("BCLSI"), whose managers are Jeffrey Schwartz and Adam Koppel, is the general partner of BCLSP and governs the investment strategy and decision-making process with respect to investments held by BCIPLS, whose general partner is Boylston Coinvestors, LLC. As a result, each of BCLSI, Mr. Schwartz and Dr. Koppel may be deemed to share voting and dispositive power over the shares held by the Bain Capital Life Sciences Entities. BCLSI, Mr. Schwartz and Dr. Koppel each disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein.

SEC source: 0000899243-20-020554 · doc4.xml · nonDerivative · entry 1

Bain Capital Life Sciences Investors, LLC · CIK 0001703031 · 10% owner

Bain Capital Life Sciences Fund, L.P. · CIK 0001687968 · 10% owner

BCIP Life Sciences Associates, LP · CIK 0001702921 · 10% owner

Koppel Adam · CIK 0001578965 · 10% owner

Bain Capital Life Sciences Partners, LP · CIK 0001703030 · 10% owner

Schwartz Jeffrey Lawrence · CIK 0001702957 · 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: 2,522,385

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 · price: Each share of Series C Preferred Stock ("Series C Stock") and Series D Preferred Stock ("Series D Stock") automatically converted on a 1-for-8.81 basis into the Issuer's Common Stock immediately prior to the closing of the Issuer's initial public offering.

F2 · ownership.nature: Represents 20,158,775 shares of Series C Stock held of record by Bain Capital Life Sciences Fund, L.P. ("BCLS") and 2,063,446 shares of Series C Stock held of record by BCIP Life Sciences Associates, LP ("BCIPLS" and, together with BCLS, the "Bain Capital Life Sciences Entities").

F5 · ownership.nature: Bain Capital Life Sciences Partners, LP ("BCLSP") is the general partner of BCLS. As a result, BCLSP may be deemed to share voting and dispositive power with respect to the securities held by BCLS. BCLSP disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F6 · ownership.nature: Bain Capital Life Sciences Investors, LLC ("BCLSI"), whose managers are Jeffrey Schwartz and Adam Koppel, is the general partner of BCLSP and governs the investment strategy and decision-making process with respect to investments held by BCIPLS, whose general partner is Boylston Coinvestors, LLC. As a result, each of BCLSI, Mr. Schwartz and Dr. Koppel may be deemed to share voting and dispositive power over the shares held by the Bain Capital Life Sciences Entities. BCLSI, Mr. Schwartz and Dr. Koppel each disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein.

SEC source: 0000899243-20-003487 · doc4.xml · derivative · entry 5

Bain Capital Life Sciences Investors, LLC · CIK 0001703031 · 10% owner

Bain Capital Life Sciences Partners, LP · CIK 0001703030 · 10% owner

Bain Capital Life Sciences Fund, L.P. · CIK 0001687968 · 10% owner

BCIP Life Sciences Associates, LP · CIK 0001702921 · 10% owner

Koppel Adam · CIK 0001578965 · 10% owner

Schwartz Jeffrey Lawrence · CIK 0001702957 · 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 · 859,573 shares

Expires not disclosed

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_price: Each share of the Issuer's Series B Preferred Stock ("Series B Stock") and Series C Preferred Stock ("Series C Stock") automatically converted into 1 share of the Issuer's Common Stock immediately prior to the closing of the Issuer's initial public offering. The Series B Stock and the Series C Stock each had no expiration date.

F1 · derivative.exercise_date: Each share of the Issuer's Series B Preferred Stock ("Series B Stock") and Series C Preferred Stock ("Series C Stock") automatically converted into 1 share of the Issuer's Common Stock immediately prior to the closing of the Issuer's initial public offering. The Series B Stock and the Series C Stock each had no expiration date.

F1 · derivative.expiration_date: Each share of the Issuer's Series B Preferred Stock ("Series B Stock") and Series C Preferred Stock ("Series C Stock") automatically converted into 1 share of the Issuer's Common Stock immediately prior to the closing of the Issuer's initial public offering. The Series B Stock and the Series C Stock each had no expiration date.

F3 · ownership.nature: Represents 779,758 shares of Series C Stock held of record by BCLS and 79,815 shares of Series C Stock held of record by BCIPLS.

F5 · ownership.nature: Bain Capital Life Sciences Partners, LP ("BCLSP") is the general partner of BCLS. As a result, BCLSP may be deemed to share voting and dispositive power with respect to the securities held by BCLS. BCLSP disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F6 · ownership.nature: Bain Capital Life Sciences Investors, LLC ("BCLSI"), whose managers are Jeffrey Schwartz and Adam Koppel, is the general partner of BCLSP and governs the investment strategy and decision-making process with respect to investments held by BCIPLS, whose general partner is Boylston Coninvestors, LLC. As a result, each of BCLSI, Mr. Schwartz and Dr. Koppel may be deemed to share voting and dipositive power with respect to the securities held by the Bain Capital Life Sciences Entities. BCLSI, Mr. Schwartz and Dr. Koppel each disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein.

SEC source: 0000899243-20-003487 · doc4.xml · derivative · entry 4

Bain Capital Life Sciences Investors, LLC · CIK 0001703031 · 10% owner

Bain Capital Life Sciences Partners, LP · CIK 0001703030 · 10% owner

Bain Capital Life Sciences Fund, L.P. · CIK 0001687968 · 10% owner

BCIP Life Sciences Associates, LP · CIK 0001702921 · 10% owner

Koppel Adam · CIK 0001578965 · 10% owner

Schwartz Jeffrey Lawrence · CIK 0001702957 · 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 · 2,825,602 shares

Expires not disclosed

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_price: Each share of the Issuer's Series B Preferred Stock ("Series B Stock") and Series C Preferred Stock ("Series C Stock") automatically converted into 1 share of the Issuer's Common Stock immediately prior to the closing of the Issuer's initial public offering. The Series B Stock and the Series C Stock each had no expiration date.

F1 · derivative.exercise_date: Each share of the Issuer's Series B Preferred Stock ("Series B Stock") and Series C Preferred Stock ("Series C Stock") automatically converted into 1 share of the Issuer's Common Stock immediately prior to the closing of the Issuer's initial public offering. The Series B Stock and the Series C Stock each had no expiration date.

F1 · derivative.expiration_date: Each share of the Issuer's Series B Preferred Stock ("Series B Stock") and Series C Preferred Stock ("Series C Stock") automatically converted into 1 share of the Issuer's Common Stock immediately prior to the closing of the Issuer's initial public offering. The Series B Stock and the Series C Stock each had no expiration date.

F2 · ownership.nature: Represents 2,563,231 shares of Series B Stock held of record by Bain Capital Life Sciences Fund, L.P. ("BCLS") and 262,371 shares of Series B Stock held of record by BCIP Life Sciences Associates, LP. ("BCIPLS" and, together with BCLS, the "Bain Capital Life Sciences Entities").

F5 · ownership.nature: Bain Capital Life Sciences Partners, LP ("BCLSP") is the general partner of BCLS. As a result, BCLSP may be deemed to share voting and dispositive power with respect to the securities held by BCLS. BCLSP disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F6 · ownership.nature: Bain Capital Life Sciences Investors, LLC ("BCLSI"), whose managers are Jeffrey Schwartz and Adam Koppel, is the general partner of BCLSP and governs the investment strategy and decision-making process with respect to investments held by BCIPLS, whose general partner is Boylston Coninvestors, LLC. As a result, each of BCLSI, Mr. Schwartz and Dr. Koppel may be deemed to share voting and dipositive power with respect to the securities held by the Bain Capital Life Sciences Entities. BCLSI, Mr. Schwartz and Dr. Koppel each disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein.

SEC source: 0000899243-20-003487 · doc4.xml · nonDerivative · entry 3

Bain Capital Life Sciences Investors, LLC · CIK 0001703031 · 10% owner

Bain Capital Life Sciences Partners, LP · CIK 0001703030 · 10% owner

Bain Capital Life Sciences Fund, L.P. · CIK 0001687968 · 10% owner

BCIP Life Sciences Associates, LP · CIK 0001702921 · 10% owner

Koppel Adam · CIK 0001578965 · 10% owner

Schwartz Jeffrey Lawrence · CIK 0001702957 · 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: 3,979,292

F4 · ownership.nature: Represents 266,807 and 27,310 shares of Common Stock purchased by BCLS and BCIPLS, respectively, in the Issuer's initial public offering.

F5 · ownership.nature: Bain Capital Life Sciences Partners, LP ("BCLSP") is the general partner of BCLS. As a result, BCLSP may be deemed to share voting and dispositive power with respect to the securities held by BCLS. BCLSP disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F6 · ownership.nature: Bain Capital Life Sciences Investors, LLC ("BCLSI"), whose managers are Jeffrey Schwartz and Adam Koppel, is the general partner of BCLSP and governs the investment strategy and decision-making process with respect to investments held by BCIPLS, whose general partner is Boylston Coninvestors, LLC. As a result, each of BCLSI, Mr. Schwartz and Dr. Koppel may be deemed to share voting and dipositive power with respect to the securities held by the Bain Capital Life Sciences Entities. BCLSI, Mr. Schwartz and Dr. Koppel each disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein.

SEC source: 0000899243-20-003487 · doc4.xml · nonDerivative · entry 2

Bain Capital Life Sciences Investors, LLC · CIK 0001703031 · 10% owner

Bain Capital Life Sciences Partners, LP · CIK 0001703030 · 10% owner

Bain Capital Life Sciences Fund, L.P. · CIK 0001687968 · 10% owner

BCIP Life Sciences Associates, LP · CIK 0001702921 · 10% owner

Koppel Adam · CIK 0001578965 · 10% owner

Schwartz Jeffrey Lawrence · CIK 0001702957 · 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: 3,685,175

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 · price: Each share of the Issuer's Series B Preferred Stock ("Series B Stock") and Series C Preferred Stock ("Series C Stock") automatically converted into 1 share of the Issuer's Common Stock immediately prior to the closing of the Issuer's initial public offering. The Series B Stock and the Series C Stock each had no expiration date.

F3 · ownership.nature: Represents 779,758 shares of Series C Stock held of record by BCLS and 79,815 shares of Series C Stock held of record by BCIPLS.

F5 · ownership.nature: Bain Capital Life Sciences Partners, LP ("BCLSP") is the general partner of BCLS. As a result, BCLSP may be deemed to share voting and dispositive power with respect to the securities held by BCLS. BCLSP disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F6 · ownership.nature: Bain Capital Life Sciences Investors, LLC ("BCLSI"), whose managers are Jeffrey Schwartz and Adam Koppel, is the general partner of BCLSP and governs the investment strategy and decision-making process with respect to investments held by BCIPLS, whose general partner is Boylston Coninvestors, LLC. As a result, each of BCLSI, Mr. Schwartz and Dr. Koppel may be deemed to share voting and dipositive power with respect to the securities held by the Bain Capital Life Sciences Entities. BCLSI, Mr. Schwartz and Dr. Koppel each disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein.

SEC source: 0000899243-20-003487 · doc4.xml · nonDerivative · entry 1

Bain Capital Life Sciences Investors, LLC · CIK 0001703031 · 10% owner

Bain Capital Life Sciences Partners, LP · CIK 0001703030 · 10% owner

Bain Capital Life Sciences Fund, L.P. · CIK 0001687968 · 10% owner

BCIP Life Sciences Associates, LP · CIK 0001702921 · 10% owner

Koppel Adam · CIK 0001578965 · 10% owner

Schwartz Jeffrey Lawrence · CIK 0001702957 · 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: 2,825,602

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 · price: Each share of the Issuer's Series B Preferred Stock ("Series B Stock") and Series C Preferred Stock ("Series C Stock") automatically converted into 1 share of the Issuer's Common Stock immediately prior to the closing of the Issuer's initial public offering. The Series B Stock and the Series C Stock each had no expiration date.

F2 · ownership.nature: Represents 2,563,231 shares of Series B Stock held of record by Bain Capital Life Sciences Fund, L.P. ("BCLS") and 262,371 shares of Series B Stock held of record by BCIP Life Sciences Associates, LP. ("BCIPLS" and, together with BCLS, the "Bain Capital Life Sciences Entities").

F5 · ownership.nature: Bain Capital Life Sciences Partners, LP ("BCLSP") is the general partner of BCLS. As a result, BCLSP may be deemed to share voting and dispositive power with respect to the securities held by BCLS. BCLSP disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F6 · ownership.nature: Bain Capital Life Sciences Investors, LLC ("BCLSI"), whose managers are Jeffrey Schwartz and Adam Koppel, is the general partner of BCLSP and governs the investment strategy and decision-making process with respect to investments held by BCIPLS, whose general partner is Boylston Coninvestors, LLC. As a result, each of BCLSI, Mr. Schwartz and Dr. Koppel may be deemed to share voting and dipositive power with respect to the securities held by the Bain Capital Life Sciences Entities. BCLSI, Mr. Schwartz and Dr. Koppel each disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein.

SEC source: 0000899243-19-027786 · doc4.xml · nonDerivative · entry 1

Bain Capital Life Sciences Investors, LLC · CIK 0001703031 · 10% owner

Bain Capital Life Sciences Partners, LP · CIK 0001703030 · 10% owner

Bain Capital Life Sciences Fund, L.P. · CIK 0001687968 · 10% owner

BCIP Life Sciences Associates, LP · CIK 0001702921 · 10% owner

Schwartz Jeffrey Lawrence · CIK 0001702957 · 10% owner

Koppel Adam · CIK 0001578965 · 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: 5,580,237

F1 · kind: On November 19, 2019 Bain Capital Life Sciences Fund, L.P. ("BC LS") and BCIP Life Sciences Associates, LP ("BCIP LS" and, together with BC LS, the "Bain Capital Life Sciences Entities") sold 1,582,973 and 167,027 shares of common stock, respectively, pursuant to Rule 144 under the Securities Act of 1933, as amended.

F2 · ownership.nature: Dr. Koppel is a director of the Issuer.

F3 · ownership.nature: Bain Capital Life Sciences Partners, LP ("BC LS P") is the general partner of BC LS. As a result, BC LS P may be deemed to share voting and dispositive power with respect to the securities held by BC LS. BC LS P disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F4 · ownership.nature: Bain Capital Life Sciences Investors, LLC ("BCI LS"), whose managers are Jeffrey Schwartz and Adam Koppel, is the general partner of BC LS P and governs the investment strategy and decision-making process with respect to investments held by BCIP LS, whose general partner is Boylston Coinvestors, LLC. As a result of the relationships described herein, each of BCI LS, Mr. Schwartz and Dr. Koppel may be deemed to share voting and dispositive power with respect to the securities held by the Bain Capital Life Sciences Entities. BCI LS, Mr. Schwartz and Dr. Koppel each disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein.

SEC source: 0000899243-19-015281 · doc4.xml · nonDerivative · entry 1

Bain Capital Life Sciences Investors, LLC · CIK 0001703031 · Director · 10% owner

Bain Capital Life Sciences Partners, LP · CIK 0001703030 · 10% owner

Bain Capital Life Sciences Fund, L.P. · CIK 0001687968 · 10% owner

BCIP Life Sciences Associates, LP · CIK 0001702921 · 10% owner

Schwartz Jeffrey Lawrence · CIK 0001702957 · 10% owner

Koppel Adam · CIK 0001578965 · 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: 7,330,237

F1 · kind: On May 29, 2019, Bain Capital Life Sciences Fund, L.P. ("BC LS") and BCIP Life Sciences Associates, LP ("BCIP LS" and, together with BC LS, the "Bain Life Sciences Entities") sold 1,447,289 and 152,711 shares of common stock, respectively, directly to a private investor.

F2 · ownership.nature: Dr. Koppel is a director of the Issuer.

F3 · ownership.nature: Bain Capital Life Sciences Partners, LP ("BC LS P") is the general partner of BC LS. As a result, BC LS P may be deemed to share voting and dispositive power with respect to the securities held by BC LS. BC LS P disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

F4 · ownership.nature: Bain Capital Life Sciences Investors, LLC ("BCI LS"), whose managers are Jeffrey Schwartz and Adam Koppel, is the general partner of BC LS P and governs the investment strategy and decision-making process with respect to investments held by BCIP LS, whose general partner is Boylston Coinvestors, LLC. As a result of the relationships described herein, each of BCI LS, Mr. Schwartz and Dr. Koppel may be deemed to share voting and dispositive power with respect to the securities held by the Bain Life Sciences Entities. BCI LS, Mr. Schwartz and Dr. Koppel each disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein.

SEC source: 0000899243-18-020659 · doc4.xml · derivative · entry 3

Bain Capital Life Sciences Investors, LLC · CIK 0001703031 · 10% owner

Bain Capital Life Sciences Partners, LP · CIK 0001703030 · 10% owner

Bain Capital Life Sciences Fund, L.P. · CIK 0001687968 · 10% owner

BCIP Life Sciences Associates, LP · CIK 0001702921 · 10% owner

Schwartz Jeffrey Lawrence · CIK 0001702957 · 10% owner

Koppel Adam · CIK 0001578965 · Director

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 · 2,338,968 shares

Expires not disclosed

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.

F3 · derivative.exercise_price: Each share of Series B Convertible Preferred Stock automatically converted into shares of Common Stock on a 1-for-9.94688 basis upon the consummation of the Issuer's initial public offering without payment or additional consideration. The shares of Series B Convertible Preferred Stock had no expiration date.

F3 · price: Each share of Series B Convertible Preferred Stock automatically converted into shares of Common Stock on a 1-for-9.94688 basis upon the consummation of the Issuer's initial public offering without payment or additional consideration. The shares of Series B Convertible Preferred Stock had no expiration date.

F3 · derivative.exercise_date: Each share of Series B Convertible Preferred Stock automatically converted into shares of Common Stock on a 1-for-9.94688 basis upon the consummation of the Issuer's initial public offering without payment or additional consideration. The shares of Series B Convertible Preferred Stock had no expiration date.

F3 · derivative.expiration_date: Each share of Series B Convertible Preferred Stock automatically converted into shares of Common Stock on a 1-for-9.94688 basis upon the consummation of the Issuer's initial public offering without payment or additional consideration. The shares of Series B Convertible Preferred Stock had no expiration date.

F3 · derivative.underlying_shares: Each share of Series B Convertible Preferred Stock automatically converted into shares of Common Stock on a 1-for-9.94688 basis upon the consummation of the Issuer's initial public offering without payment or additional consideration. The shares of Series B Convertible Preferred Stock had no expiration date.

F1 · ownership.nature: Represents shares held directly by Bain Capital Life Sciences Fund, L.P. and BCIP Life Sciences Associates, LP (collectively, the "Bain Life Sciences Entities").

F2 · ownership.nature: The governance, investment strategy and decision-making process with respect to investments held by the Bain Life Sciences Entities is directed by Bain Capital Life Sciences Investors, LLC ("BCI LS"), whose managers are Jeffrey Schwartz and Adam Koppel. As a result, BCI LS, Mr. Schwartz and Dr. Koppel may each be deemed to share voting and dispositive power with respect to the securities held by the Bain Life Sciences Entities. BCI LS, Mr. Schwartz and Dr. Koppel each disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein.

SEC source: 0000899243-18-020659 · doc4.xml · nonDerivative · entry 2

Bain Capital Life Sciences Investors, LLC · CIK 0001703031 · 10% owner

Bain Capital Life Sciences Partners, LP · CIK 0001703030 · 10% owner

Bain Capital Life Sciences Fund, L.P. · CIK 0001687968 · 10% owner

BCIP Life Sciences Associates, LP · CIK 0001702921 · 10% owner

Schwartz Jeffrey Lawrence · CIK 0001702957 · 10% owner

Koppel Adam · CIK 0001578965 · Director

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 2,838,968

F4 · shares: On July 24, 2018, the Bain Life Sciences Entities purchased, in aggregate, 500,000 shares of Common Stock of the Issuer at a price of $15 per share, pursuant to an underwritten public offering.

F1 · ownership.nature: Represents shares held directly by Bain Capital Life Sciences Fund, L.P. and BCIP Life Sciences Associates, LP (collectively, the "Bain Life Sciences Entities").

F2 · ownership.nature: The governance, investment strategy and decision-making process with respect to investments held by the Bain Life Sciences Entities is directed by Bain Capital Life Sciences Investors, LLC ("BCI LS"), whose managers are Jeffrey Schwartz and Adam Koppel. As a result, BCI LS, Mr. Schwartz and Dr. Koppel may each be deemed to share voting and dispositive power with respect to the securities held by the Bain Life Sciences Entities. BCI LS, Mr. Schwartz and Dr. Koppel each disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein.

SEC source: 0000899243-18-020659 · doc4.xml · nonDerivative · entry 1

Bain Capital Life Sciences Investors, LLC · CIK 0001703031 · 10% owner

Bain Capital Life Sciences Partners, LP · CIK 0001703030 · 10% owner

Bain Capital Life Sciences Fund, L.P. · CIK 0001687968 · 10% owner

BCIP Life Sciences Associates, LP · CIK 0001702921 · 10% owner

Schwartz Jeffrey Lawrence · CIK 0001702957 · 10% owner

Koppel Adam · CIK 0001578965 · Director

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 2,338,968

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.

F3 · kind: Each share of Series B Convertible Preferred Stock automatically converted into shares of Common Stock on a 1-for-9.94688 basis upon the consummation of the Issuer's initial public offering without payment or additional consideration. The shares of Series B Convertible Preferred Stock had no expiration date.

F3 · shares: Each share of Series B Convertible Preferred Stock automatically converted into shares of Common Stock on a 1-for-9.94688 basis upon the consummation of the Issuer's initial public offering without payment or additional consideration. The shares of Series B Convertible Preferred Stock had no expiration date.

F3 · price: Each share of Series B Convertible Preferred Stock automatically converted into shares of Common Stock on a 1-for-9.94688 basis upon the consummation of the Issuer's initial public offering without payment or additional consideration. The shares of Series B Convertible Preferred Stock had no expiration date.

F3 · balance_after: Each share of Series B Convertible Preferred Stock automatically converted into shares of Common Stock on a 1-for-9.94688 basis upon the consummation of the Issuer's initial public offering without payment or additional consideration. The shares of Series B Convertible Preferred Stock had no expiration date.

F1 · ownership.nature: Represents shares held directly by Bain Capital Life Sciences Fund, L.P. and BCIP Life Sciences Associates, LP (collectively, the "Bain Life Sciences Entities").

F2 · ownership.nature: The governance, investment strategy and decision-making process with respect to investments held by the Bain Life Sciences Entities is directed by Bain Capital Life Sciences Investors, LLC ("BCI LS"), whose managers are Jeffrey Schwartz and Adam Koppel. As a result, BCI LS, Mr. Schwartz and Dr. Koppel may each be deemed to share voting and dispositive power with respect to the securities held by the Bain Life Sciences Entities. BCI LS, Mr. Schwartz and Dr. Koppel each disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein.

SEC source: 0000899243-17-029256 · doc4.xml · nonDerivative · entry 5

Bain Capital Life Sciences Investors, LLC · CIK 0001703031 · 10% owner

Bain Capital Life Sciences Partners, LP · CIK 0001703030 · 10% owner

Bain Capital Life Sciences Fund, L.P. · CIK 0001687968 · 10% owner

BCIP Life Sciences Associates, LP · CIK 0001702921 · 10% owner

Schwartz Jeffrey Lawrence · CIK 0001702957 · 10% owner

Koppel Adam · CIK 0001578965 · 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: 3,977,453

F5 · shares: On December 19, 2017, BC LS and BCIP LS sold 50,101 and 5,128 shares of common stock, respectively, at a weighted average price of $7.1055. The shares were sold in multiple transactions at prices ranging from $6.86 to $7.498. Following such sales, BC LS and BCIP LS held 3,608,127 and 369,326 shares of common stock, respectively.

F6 · shares: Each of the Bain Life Sciences Entities undertakes to provide to 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 footnotes (1) through (5) to this Form 4.

F5 · price: On December 19, 2017, BC LS and BCIP LS sold 50,101 and 5,128 shares of common stock, respectively, at a weighted average price of $7.1055. The shares were sold in multiple transactions at prices ranging from $6.86 to $7.498. Following such sales, BC LS and BCIP LS held 3,608,127 and 369,326 shares of common stock, respectively.

F6 · price: Each of the Bain Life Sciences Entities undertakes to provide to 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 footnotes (1) through (5) to this Form 4.

F7 · ownership.nature: Bain Capital Life Sciences Investors, LLC ("BCI LS") is the general partner of Bain Capital Life Sciences Partners, LP ("BC LS P"), which is the general partner of BC LS. As a result, BC LS P may be deemed to share voting and dispositive power with respect to the securities held by BC LS.

F8 · ownership.nature: The governance, investment strategy and decision-making process with respect to the investments held by the Bain Life Sciences Entities is directed by BCI LS, whose managers are Jeffrey Schwartz and Adam Koppel. As a result, BCI LS, Mr. Schwartz and Dr. Koppel may each be deemed to share voting and dispositive power with respect to the securities held by the Bain Life Sciences Entities. BCI LS, Mr. Schwartz and Dr. Koppel each disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein.

SEC source: 0000899243-17-029256 · doc4.xml · nonDerivative · entry 4

Bain Capital Life Sciences Investors, LLC · CIK 0001703031 · 10% owner

Bain Capital Life Sciences Partners, LP · CIK 0001703030 · 10% owner

Bain Capital Life Sciences Fund, L.P. · CIK 0001687968 · 10% owner

BCIP Life Sciences Associates, LP · CIK 0001702921 · 10% owner

Schwartz Jeffrey Lawrence · CIK 0001702957 · 10% owner

Koppel Adam · CIK 0001578965 · 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: 4,032,682

F4 · shares: On December 19, 2017, BC LS and BCIP LS sold 85,971 and 8,800 shares of common stock, respectively, at a weighted average price of $7.6209. The shares were sold in multiple transactions at prices ranging from $7.50 to $8.02. Following such sales, BC LS and BCIP LS held 3,658,228 and 374,454 shares of common stock, respectively.

F6 · shares: Each of the Bain Life Sciences Entities undertakes to provide to 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 footnotes (1) through (5) to this Form 4.

F4 · price: On December 19, 2017, BC LS and BCIP LS sold 85,971 and 8,800 shares of common stock, respectively, at a weighted average price of $7.6209. The shares were sold in multiple transactions at prices ranging from $7.50 to $8.02. Following such sales, BC LS and BCIP LS held 3,658,228 and 374,454 shares of common stock, respectively.

F6 · price: Each of the Bain Life Sciences Entities undertakes to provide to 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 footnotes (1) through (5) to this Form 4.

F7 · ownership.nature: Bain Capital Life Sciences Investors, LLC ("BCI LS") is the general partner of Bain Capital Life Sciences Partners, LP ("BC LS P"), which is the general partner of BC LS. As a result, BC LS P may be deemed to share voting and dispositive power with respect to the securities held by BC LS.

F8 · ownership.nature: The governance, investment strategy and decision-making process with respect to the investments held by the Bain Life Sciences Entities is directed by BCI LS, whose managers are Jeffrey Schwartz and Adam Koppel. As a result, BCI LS, Mr. Schwartz and Dr. Koppel may each be deemed to share voting and dispositive power with respect to the securities held by the Bain Life Sciences Entities. BCI LS, Mr. Schwartz and Dr. Koppel each disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein.

SEC source: 0000899243-17-029183 · doc4.xml · derivative · entry 4

Bain Capital Life Sciences Investors, LLC · CIK 0001703031 · Director · 10% owner

Bain Capital Life Sciences Partners, LP · CIK 0001703030 · Director · 10% owner

Bain Capital Life Sciences Fund, L.P. · CIK 0001687968 · Director · 10% owner

BCIP Life Sciences Associates, LP · CIK 0001702921 · Director · 10% owner

Schwartz Jeffrey Lawrence · CIK 0001702957 · Director · 10% owner

Koppel Adam · CIK 0001578965 · 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 · 8,454,388 shares

Expires not disclosed

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: Each share of Redeemable Convertible Preferred Stock had a stated value of $100 (the "Stated Value") and accrued dividends daily at an initial rate of 12% per annum, which was reduced to 8% per annum on October 28, 2017 in accordance with the Certificate of Designations for the Redeemable Convertible Preferred Stock. The Stated Value, as adjusted to give effect to such dividends, was referred to as the "Accrued Value." Each share of Redeemable Convertible Preferred Stock was convertible, at the option of the holder or, upon the occurrence of certain events, at the option of the Issuer, into a number of shares of common stock determined by dividing the Accrued Value by the conversion price. The Redeemable Convertible Preferred Stock was not convertible to the extent that such conversion would have resulted in the beneficial owner of such Redeemable Convertible Preferred Stock and its affiliates owning in excess of 19.99% of the Issuer's voting power.

F3 · derivative.exercise_price: On December 18, 2017, the 226,139 shares of Redeemable Convertible Preferred Stock held by BC LS and the 23,861 shares of Redeemable Convertible Preferred Stock held by BCIP LS were converted, at the option of the Bain Life Sciences Entities, into 7,647,468 and 806,920 shares of common stock, respectively.

F2 · derivative.exercise_date: Each share of Redeemable Convertible Preferred Stock had a stated value of $100 (the "Stated Value") and accrued dividends daily at an initial rate of 12% per annum, which was reduced to 8% per annum on October 28, 2017 in accordance with the Certificate of Designations for the Redeemable Convertible Preferred Stock. The Stated Value, as adjusted to give effect to such dividends, was referred to as the "Accrued Value." Each share of Redeemable Convertible Preferred Stock was convertible, at the option of the holder or, upon the occurrence of certain events, at the option of the Issuer, into a number of shares of common stock determined by dividing the Accrued Value by the conversion price. The Redeemable Convertible Preferred Stock was not convertible to the extent that such conversion would have resulted in the beneficial owner of such Redeemable Convertible Preferred Stock and its affiliates owning in excess of 19.99% of the Issuer's voting power.

F3 · derivative.exercise_date: On December 18, 2017, the 226,139 shares of Redeemable Convertible Preferred Stock held by BC LS and the 23,861 shares of Redeemable Convertible Preferred Stock held by BCIP LS were converted, at the option of the Bain Life Sciences Entities, into 7,647,468 and 806,920 shares of common stock, respectively.

F2 · derivative.expiration_date: Each share of Redeemable Convertible Preferred Stock had a stated value of $100 (the "Stated Value") and accrued dividends daily at an initial rate of 12% per annum, which was reduced to 8% per annum on October 28, 2017 in accordance with the Certificate of Designations for the Redeemable Convertible Preferred Stock. The Stated Value, as adjusted to give effect to such dividends, was referred to as the "Accrued Value." Each share of Redeemable Convertible Preferred Stock was convertible, at the option of the holder or, upon the occurrence of certain events, at the option of the Issuer, into a number of shares of common stock determined by dividing the Accrued Value by the conversion price. The Redeemable Convertible Preferred Stock was not convertible to the extent that such conversion would have resulted in the beneficial owner of such Redeemable Convertible Preferred Stock and its affiliates owning in excess of 19.99% of the Issuer's voting power.

F3 · derivative.expiration_date: On December 18, 2017, the 226,139 shares of Redeemable Convertible Preferred Stock held by BC LS and the 23,861 shares of Redeemable Convertible Preferred Stock held by BCIP LS were converted, at the option of the Bain Life Sciences Entities, into 7,647,468 and 806,920 shares of common stock, respectively.

F5 · ownership.nature: Bain Capital Life Sciences Investors, LLC ("BCI LS") is the general partner of Bain Capital Life Sciences Partners, LP ("BC LS P"), which is the general partner of BC LS. As a result, BC LS P may be deemed to share voting and dispositive power with respect to the securities held by BC LS.

F6 · ownership.nature: The governance, investment strategy and decision-making process with respect to the investments held by the Bain Life Sciences Entities is directed by BCI LS, whose managers are Jeffrey Schwartz and Adam Koppel. As a result, BCI LS, Mr. Schwartz and Dr. Koppel may each be deemed to share voting and dispositive power with respect to the securities held by the Bain Life Sciences Entities. BCI LS, Mr. Schwartz and Dr. Koppel each disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein.

SEC source: 0000899243-17-029183 · doc4.xml · nonDerivative · entry 3

Bain Capital Life Sciences Investors, LLC · CIK 0001703031 · Director · 10% owner

Bain Capital Life Sciences Partners, LP · CIK 0001703030 · Director · 10% owner

Bain Capital Life Sciences Fund, L.P. · CIK 0001687968 · Director · 10% owner

BCIP Life Sciences Associates, LP · CIK 0001702921 · Director · 10% owner

Schwartz Jeffrey Lawrence · CIK 0001702957 · Director · 10% owner

Koppel Adam · CIK 0001578965 · 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: 8,930,237

F2 · price: Each share of Redeemable Convertible Preferred Stock had a stated value of $100 (the "Stated Value") and accrued dividends daily at an initial rate of 12% per annum, which was reduced to 8% per annum on October 28, 2017 in accordance with the Certificate of Designations for the Redeemable Convertible Preferred Stock. The Stated Value, as adjusted to give effect to such dividends, was referred to as the "Accrued Value." Each share of Redeemable Convertible Preferred Stock was convertible, at the option of the holder or, upon the occurrence of certain events, at the option of the Issuer, into a number of shares of common stock determined by dividing the Accrued Value by the conversion price. The Redeemable Convertible Preferred Stock was not convertible to the extent that such conversion would have resulted in the beneficial owner of such Redeemable Convertible Preferred Stock and its affiliates owning in excess of 19.99% of the Issuer's voting power.

F4 · price: On December 18, 2017, each of BC LS and BCIP LS received an additional 172,633 and 18,216 shares of common stock, respectively, from the Issuer representing the additional dividend accruals on the Redeemable Convertible Preferred Stock that each of BC LS and BCIP LS would have been entitled to receive up to and including March 31, 2018.

F5 · ownership.nature: Bain Capital Life Sciences Investors, LLC ("BCI LS") is the general partner of Bain Capital Life Sciences Partners, LP ("BC LS P"), which is the general partner of BC LS. As a result, BC LS P may be deemed to share voting and dispositive power with respect to the securities held by BC LS.

F6 · ownership.nature: The governance, investment strategy and decision-making process with respect to the investments held by the Bain Life Sciences Entities is directed by BCI LS, whose managers are Jeffrey Schwartz and Adam Koppel. As a result, BCI LS, Mr. Schwartz and Dr. Koppel may each be deemed to share voting and dispositive power with respect to the securities held by the Bain Life Sciences Entities. BCI LS, Mr. Schwartz and Dr. Koppel each disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein.

SEC source: 0000899243-17-029183 · doc4.xml · nonDerivative · entry 2

Bain Capital Life Sciences Investors, LLC · CIK 0001703031 · Director · 10% owner

Bain Capital Life Sciences Partners, LP · CIK 0001703030 · Director · 10% owner

Bain Capital Life Sciences Fund, L.P. · CIK 0001687968 · Director · 10% owner

BCIP Life Sciences Associates, LP · CIK 0001702921 · Director · 10% owner

Schwartz Jeffrey Lawrence · CIK 0001702957 · Director · 10% owner

Koppel Adam · CIK 0001578965 · 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: 8,739,388

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 · price: Each share of Redeemable Convertible Preferred Stock had a stated value of $100 (the "Stated Value") and accrued dividends daily at an initial rate of 12% per annum, which was reduced to 8% per annum on October 28, 2017 in accordance with the Certificate of Designations for the Redeemable Convertible Preferred Stock. The Stated Value, as adjusted to give effect to such dividends, was referred to as the "Accrued Value." Each share of Redeemable Convertible Preferred Stock was convertible, at the option of the holder or, upon the occurrence of certain events, at the option of the Issuer, into a number of shares of common stock determined by dividing the Accrued Value by the conversion price. The Redeemable Convertible Preferred Stock was not convertible to the extent that such conversion would have resulted in the beneficial owner of such Redeemable Convertible Preferred Stock and its affiliates owning in excess of 19.99% of the Issuer's voting power.

F3 · price: On December 18, 2017, the 226,139 shares of Redeemable Convertible Preferred Stock held by BC LS and the 23,861 shares of Redeemable Convertible Preferred Stock held by BCIP LS were converted, at the option of the Bain Life Sciences Entities, into 7,647,468 and 806,920 shares of common stock, respectively.

F5 · ownership.nature: Bain Capital Life Sciences Investors, LLC ("BCI LS") is the general partner of Bain Capital Life Sciences Partners, LP ("BC LS P"), which is the general partner of BC LS. As a result, BC LS P may be deemed to share voting and dispositive power with respect to the securities held by BC LS.

F6 · ownership.nature: The governance, investment strategy and decision-making process with respect to the investments held by the Bain Life Sciences Entities is directed by BCI LS, whose managers are Jeffrey Schwartz and Adam Koppel. As a result, BCI LS, Mr. Schwartz and Dr. Koppel may each be deemed to share voting and dispositive power with respect to the securities held by the Bain Life Sciences Entities. BCI LS, Mr. Schwartz and Dr. Koppel each disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein.

SEC source: 0000899243-17-029183 · doc4.xml · nonDerivative · entry 1

Bain Capital Life Sciences Investors, LLC · CIK 0001703031 · Director · 10% owner

Bain Capital Life Sciences Partners, LP · CIK 0001703030 · Director · 10% owner

Bain Capital Life Sciences Fund, L.P. · CIK 0001687968 · Director · 10% owner

BCIP Life Sciences Associates, LP · CIK 0001702921 · Director · 10% owner

Schwartz Jeffrey Lawrence · CIK 0001702957 · Director · 10% owner

Koppel Adam · CIK 0001578965 · 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: 285,000

F1 · kind: On December 18, 2017, Bain Capital Life Sciences Fund, L.P. ("BC LS") and BCIP Life Sciences Associates, LP ("BCIP LS" and, together with BC LS, the "Bain Life Sciences Entities") purchased 257,798 and 27,202 shares of common stock, respectively, in an underwritten public offering.

F5 · ownership.nature: Bain Capital Life Sciences Investors, LLC ("BCI LS") is the general partner of Bain Capital Life Sciences Partners, LP ("BC LS P"), which is the general partner of BC LS. As a result, BC LS P may be deemed to share voting and dispositive power with respect to the securities held by BC LS.

F6 · ownership.nature: The governance, investment strategy and decision-making process with respect to the investments held by the Bain Life Sciences Entities is directed by BCI LS, whose managers are Jeffrey Schwartz and Adam Koppel. As a result, BCI LS, Mr. Schwartz and Dr. Koppel may each be deemed to share voting and dispositive power with respect to the securities held by the Bain Life Sciences Entities. BCI LS, Mr. Schwartz and Dr. Koppel each disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein.

SEC source: 0000899243-17-029256 · doc4.xml · nonDerivative · entry 3

Bain Capital Life Sciences Investors, LLC · CIK 0001703031 · 10% owner

Bain Capital Life Sciences Partners, LP · CIK 0001703030 · 10% owner

Bain Capital Life Sciences Fund, L.P. · CIK 0001687968 · 10% owner

BCIP Life Sciences Associates, LP · CIK 0001702921 · 10% owner

Schwartz Jeffrey Lawrence · CIK 0001702957 · 10% owner

Koppel Adam · CIK 0001578965 · 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: 4,127,453

F3 · shares: On December 18, 2017, BC LS and BCIP LS sold 272,143 and 27,857 shares of common stock, respectively, at a weighted average price of $7.5048. The shares were sold in multiple transactions at prices ranging from $7.05 to $7.905. Following such sales, BC LS and BCIP LS held 3,744,199 and 383,254 shares of common stock, respectively.

F6 · shares: Each of the Bain Life Sciences Entities undertakes to provide to 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 footnotes (1) through (5) to this Form 4.

F3 · price: On December 18, 2017, BC LS and BCIP LS sold 272,143 and 27,857 shares of common stock, respectively, at a weighted average price of $7.5048. The shares were sold in multiple transactions at prices ranging from $7.05 to $7.905. Following such sales, BC LS and BCIP LS held 3,744,199 and 383,254 shares of common stock, respectively.

F6 · price: Each of the Bain Life Sciences Entities undertakes to provide to 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 footnotes (1) through (5) to this Form 4.

F7 · ownership.nature: Bain Capital Life Sciences Investors, LLC ("BCI LS") is the general partner of Bain Capital Life Sciences Partners, LP ("BC LS P"), which is the general partner of BC LS. As a result, BC LS P may be deemed to share voting and dispositive power with respect to the securities held by BC LS.

F8 · ownership.nature: The governance, investment strategy and decision-making process with respect to the investments held by the Bain Life Sciences Entities is directed by BCI LS, whose managers are Jeffrey Schwartz and Adam Koppel. As a result, BCI LS, Mr. Schwartz and Dr. Koppel may each be deemed to share voting and dispositive power with respect to the securities held by the Bain Life Sciences Entities. BCI LS, Mr. Schwartz and Dr. Koppel each disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein.

SEC source: 0000899243-17-029256 · doc4.xml · nonDerivative · entry 2

Bain Capital Life Sciences Investors, LLC · CIK 0001703031 · 10% owner

Bain Capital Life Sciences Partners, LP · CIK 0001703030 · 10% owner

Bain Capital Life Sciences Fund, L.P. · CIK 0001687968 · 10% owner

BCIP Life Sciences Associates, LP · CIK 0001702921 · 10% owner

Schwartz Jeffrey Lawrence · CIK 0001702957 · 10% owner

Koppel Adam · CIK 0001578965 · 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: 4,427,453

F2 · shares: On December 15, 2017, BC LS and BCIP LS sold 93,329 and 9,553 shares of common stock, respectively, at a weighted average price of $8.636. The shares were sold in multiple transactions at prices ranging from $8.50 to $9.045. Following such sales, BC LS and BCIP LS held 4,016,342 and 411,111 shares of common stock, respectively.

F6 · shares: Each of the Bain Life Sciences Entities undertakes to provide to 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 footnotes (1) through (5) to this Form 4.

F2 · price: On December 15, 2017, BC LS and BCIP LS sold 93,329 and 9,553 shares of common stock, respectively, at a weighted average price of $8.636. The shares were sold in multiple transactions at prices ranging from $8.50 to $9.045. Following such sales, BC LS and BCIP LS held 4,016,342 and 411,111 shares of common stock, respectively.

F6 · price: Each of the Bain Life Sciences Entities undertakes to provide to 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 footnotes (1) through (5) to this Form 4.

F7 · ownership.nature: Bain Capital Life Sciences Investors, LLC ("BCI LS") is the general partner of Bain Capital Life Sciences Partners, LP ("BC LS P"), which is the general partner of BC LS. As a result, BC LS P may be deemed to share voting and dispositive power with respect to the securities held by BC LS.

F8 · ownership.nature: The governance, investment strategy and decision-making process with respect to the investments held by the Bain Life Sciences Entities is directed by BCI LS, whose managers are Jeffrey Schwartz and Adam Koppel. As a result, BCI LS, Mr. Schwartz and Dr. Koppel may each be deemed to share voting and dispositive power with respect to the securities held by the Bain Life Sciences Entities. BCI LS, Mr. Schwartz and Dr. Koppel each disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein.

SEC source: 0000899243-17-029256 · doc4.xml · nonDerivative · entry 1

Bain Capital Life Sciences Investors, LLC · CIK 0001703031 · 10% owner

Bain Capital Life Sciences Partners, LP · CIK 0001703030 · 10% owner

Bain Capital Life Sciences Fund, L.P. · CIK 0001687968 · 10% owner

BCIP Life Sciences Associates, LP · CIK 0001702921 · 10% owner

Schwartz Jeffrey Lawrence · CIK 0001702957 · 10% owner

Koppel Adam · CIK 0001578965 · 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: 4,530,335

F1 · shares: On December 15, 2017, Bain Capital Life Sciences Fund, L.P. ("BC LS") and BCIP Life Sciences Associates, LP ("BCIP LS" and, together with BC LS, the "Bain Life Sciences Entities") sold 652,840 and 66,825 shares of common stock, respectively, at a weighted average price of $8.0179. The shares were sold in multiple transactions at prices ranging from $7.89 to $8.495. Following such sales, BC LS and BCIP LS held 4,109,671 and 420,664 shares of common stock, respectively.

F6 · shares: Each of the Bain Life Sciences Entities undertakes to provide to 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 footnotes (1) through (5) to this Form 4.

F1 · price: On December 15, 2017, Bain Capital Life Sciences Fund, L.P. ("BC LS") and BCIP Life Sciences Associates, LP ("BCIP LS" and, together with BC LS, the "Bain Life Sciences Entities") sold 652,840 and 66,825 shares of common stock, respectively, at a weighted average price of $8.0179. The shares were sold in multiple transactions at prices ranging from $7.89 to $8.495. Following such sales, BC LS and BCIP LS held 4,109,671 and 420,664 shares of common stock, respectively.

F6 · price: Each of the Bain Life Sciences Entities undertakes to provide to 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 footnotes (1) through (5) to this Form 4.

F7 · ownership.nature: Bain Capital Life Sciences Investors, LLC ("BCI LS") is the general partner of Bain Capital Life Sciences Partners, LP ("BC LS P"), which is the general partner of BC LS. As a result, BC LS P may be deemed to share voting and dispositive power with respect to the securities held by BC LS.

F8 · ownership.nature: The governance, investment strategy and decision-making process with respect to the investments held by the Bain Life Sciences Entities is directed by BCI LS, whose managers are Jeffrey Schwartz and Adam Koppel. As a result, BCI LS, Mr. Schwartz and Dr. Koppel may each be deemed to share voting and dispositive power with respect to the securities held by the Bain Life Sciences Entities. BCI LS, Mr. Schwartz and Dr. Koppel each disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein.