REPL

SEC source: 0001104659-19-019709 · a4.xml · derivative · entry 1

Weinand Dieter · CIK 0001744419 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 13,500

Underlying: Common Stock · 13,500 shares

Expires 2029-04-01

F1 · derivative.exercise_date: The shares underlying this option vest entirely on April 1, 2020.

SEC source: 0000899243-19-009840 · doc4.xml · derivative · entry 1

Omega Fund IV, L.P. · CIK 0001528382 · 10% owner

Omega Fund IV GP, L.P. · CIK 0001528383 · 10% owner

Omega Fund IV G.P. Manager, Ltd. · CIK 0001624456 · 10% owner

Stampacchia Otello · CIK 0001361712 · Director · 10% owner

Lim Richard J. · CIK 0001623720 · 10% owner

Paster Anne-Mari · CIK 0001652863 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 13,500

Underlying: Common Stock · 13,500 shares

Expires not disclosed

F1 · derivative.exercise_date: The Common Stock Options (the "Options") were granted to Otello Stampacchia in his capacity as a director of the issuer on April 1, 2019 (the "Grant Date"), with the Options vesting on the first anniversary of the Grant Date. The Options expire on the tenth anniversary of the Grant Date. The Options are held directly by Mr. Stampacchia.

F1 · derivative.expiration_date: The Common Stock Options (the "Options") were granted to Otello Stampacchia in his capacity as a director of the issuer on April 1, 2019 (the "Grant Date"), with the Options vesting on the first anniversary of the Grant Date. The Options expire on the tenth anniversary of the Grant Date. The Options are held directly by Mr. Stampacchia.

F1 · balance_after: The Common Stock Options (the "Options") were granted to Otello Stampacchia in his capacity as a director of the issuer on April 1, 2019 (the "Grant Date"), with the Options vesting on the first anniversary of the Grant Date. The Options expire on the tenth anniversary of the Grant Date. The Options are held directly by Mr. Stampacchia.

F1 · ownership.direct: The Common Stock Options (the "Options") were granted to Otello Stampacchia in his capacity as a director of the issuer on April 1, 2019 (the "Grant Date"), with the Options vesting on the first anniversary of the Grant Date. The Options expire on the tenth anniversary of the Grant Date. The Options are held directly by Mr. Stampacchia.

SEC source: 0001104659-19-019720 · a4.xml · derivative · entry 1

Dhingra Kapil · CIK 0001456849 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 13,500

Underlying: Common Stock · 13,500 shares

Expires 2029-04-01

F1 · derivative.exercise_date: The shares underlying this option vest entirely on April 1, 2020.

SEC source: 0001104659-19-019707 · a4.xml · derivative · entry 1

Astley-Sparke Philip · CIK 0001376491 · Director · Executive Chairman

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 153,050

Underlying: Common Stock · 153,050 shares

Expires 2029-04-01

F1 · derivative.exercise_date: 25% of the shares underlying this stock option vest on April 1, 2020, and the remainder of the shares underlying this stock option vest in 36 approximately equal monthly installments thereafter.

SEC source: 0001104659-19-019721 · a4.xml · derivative · entry 1

GORGOL STEPHEN A · CIK 0001287980 · Chief Accounting Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 55,000

Underlying: Common Stock · 55,000 shares

Expires 2029-04-01

F1 · derivative.exercise_date: 25% of the shares underlying this stock option vest on April 1, 2020, and the remainder of the shares underlying this stock option vest in 36 approximately equal monthly installments thereafter.

SEC source: 0001104659-19-019710 · a4.xml · derivative · entry 1

SLATTERY JOSEPH P · CIK 0001246530 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 13,500

Underlying: Common Stock · 13,500 shares

Expires 2029-04-01

F1 · derivative.exercise_date: The shares underlying this option vest entirely on April 1, 2020.

SEC source: 0001104659-19-019724 · a4.xml · derivative · entry 1

Love Colin · CIK 0001376493 · Chief Operating Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 78,900

Underlying: Common Stock · 78,900 shares

Expires 2029-04-01

F1 · derivative.exercise_date: 25% of the shares underlying this stock option vest on April 1, 2020, and the remainder of the shares underlying this stock option vest in 36 approximately equal monthly installments thereafter.

SEC source: 0001104659-19-019715 · a4.xml · derivative · entry 1

Levitsky Hyam · CIK 0001375792 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 13,500

Underlying: Common Stock · 13,500 shares

Expires 2029-04-01

F1 · derivative.exercise_date: The shares underlying this option vest entirely on April 1, 2020.

SEC source: 0001104659-19-019706 · a4.xml · derivative · entry 1

Coffin Robert · CIK 0001376492 · Director · President and C.E.O.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 219,300

Underlying: Common Stock · 219,300 shares

Expires 2029-04-01

F1 · derivative.exercise_date: 25% of the shares underlying this stock option vest on April 1, 2020, and the remainder of the shares underlying this stock option vest in 36 approximately equal monthly installments thereafter.

SEC source: 0001104659-19-019704 · a4.xml · derivative · entry 1

Rhodes Jason P · CIK 0001577014 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 13,500

Underlying: Common Stock · 13,500 shares

Expires 2029-04-01

F1 · derivative.exercise_date: This option was granted on April 1, 2019 with respect to 13,500 shares of the Issuer's common stock and vests in full on April 1, 2020.

F2 · ownership.direct: The Reporting Person is a member of Atlas Venture Associates X, LLC and is obligated to transfer the economic benefit, if any, received upon the sale of the shares issuable upon exercise of the option to Atlas Venture Life Science Advisors, LLC. As such, the Reporting Person disclaims beneficial ownership of the securities reported herein for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001104659-19-019727 · a4.xml · derivative · entry 1

Slootweg Hugo Alexander · CIK 0001744922 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 13,500

Underlying: Common Stock · 13,500 shares

Expires 2029-04-01

F1 · derivative.exercise_date: The shares underlying this option vest entirely on April 1, 2020.

SEC source: 0001104659-19-019723 · a4.xml · derivative · entry 1

Kaufman Howard · CIK 0001744424 · Chief Medical Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 80,500

Underlying: Common Stock · 80,500 shares

Expires 2029-04-01

F1 · derivative.exercise_date: 25% of the shares underlying this stock option vest on April 1, 2020, and the remainder of the shares underlying this stock option vest in 36 approximately equal monthly installments thereafter.

SEC source: 0001104659-19-019705 · a4.xml · derivative · entry 1

Esposito Pamela · CIK 0001744425 · Chief Business Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 75,750

Underlying: Common Stock · 75,750 shares

Expires 2029-04-01

F1 · derivative.exercise_date: 25% of the shares underlying this stock option vest on April 1, 2020, and the remainder of the shares underlying this stock option vest in 36 approximately equal monthly installments thereafter.

SEC source: 0001209191-19-010172 · doc4.xml · nonDerivative · entry 1

Atlas Venture Fund X, L.P. · CIK 0001628098 · 10% owner

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 3,822,313

F1 · kind: Represent a pro rata distribution, and not a purchase or sale of securities, by Atlas Venture Fund X, L.P. to its general partner and limited partners without additional consideration. This distribution was effected pursuant to a plan adopted in accordance with Rule 10b5-1 on August 22, 2018.

SEC source: 0001104659-18-073330 · a4.xml · derivative · entry 2

Esposito Pamela · CIK 0001744425 · Chief Business Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 109,162

Underlying: Common Stock · 87,000 shares

Expires 2026-03-01

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

F1 · derivative.exercise_date: The reporting person was granted a stock option to acquire 196,162 shares of the Issuer's common stock, subject to vesting. 134,846 shares underlying the stock option have vested with the remaining 61,316 shares underlying the stock option to vest in 15 equal monthly installments as of the 29th of each month.

SEC source: 0001104659-18-073330 · a4.xml · nonDerivative · entry 1

Esposito Pamela · CIK 0001744425 · Chief Business Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 87,000

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

SEC source: 0000899243-18-020583 · doc4.xml · derivative · entry 9

Omega Fund IV, L.P. · CIK 0001528382 · 10% owner

Omega Fund IV GP, L.P. · CIK 0001528383 · 10% owner

Omega Fund IV G.P. Manager, Ltd. · CIK 0001624456 · 10% owner

Stampacchia Otello · CIK 0001361712 · Director · 10% owner

Lim Richard J. · CIK 0001623720 · 10% owner

Paster Anne-Mari · CIK 0001652863 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 1,013,547 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.

F4 · derivative.exercise_price: The Series B Convertible Preferred Stock ("Series B") converted automatically into shares of the issuer's common stock on a 1-for-9.94688 basis upon the completion of IPO. The Series B had no expiration date.

F4 · derivative.exercise_date: The Series B Convertible Preferred Stock ("Series B") converted automatically into shares of the issuer's common stock on a 1-for-9.94688 basis upon the completion of IPO. The Series B had no expiration date.

F4 · derivative.expiration_date: The Series B Convertible Preferred Stock ("Series B") converted automatically into shares of the issuer's common stock on a 1-for-9.94688 basis upon the completion of IPO. The Series B had no expiration date.

F1 · ownership.direct: The reported securities are beneficially owned by Omega Fund IV, L.P. ("Omega IV"). The reported securities may be deemed to be beneficially owned by each of Omega Fund IV GP, L.P. ("Omega IV GP"), as the general partner of Omega IV, and Omega Fund IV GP Manager, Ltd. ("Omega IV GP Manager"), as the general partner of Omega IV GP. Otello Stampacchia, Richard Lim and Anne-Mari Paster are all the shareholders and directors of Omega IV GP Manager and have shared voting and investment power over the shares held by Omega IV and, as a result, may each be deemed to beneficially own the reported securities. Otello Stampacchia is also a director of the issuer. Each of the Reporting Persons disclaims beneficial ownership of the reported securities, except to the extent of his, her or its pecuniary interest therein.

SEC source: 0000899243-18-020583 · doc4.xml · derivative · entry 8

Omega Fund IV, L.P. · CIK 0001528382 · 10% owner

Omega Fund IV GP, L.P. · CIK 0001528383 · 10% owner

Omega Fund IV G.P. Manager, Ltd. · CIK 0001624456 · 10% owner

Stampacchia Otello · CIK 0001361712 · Director · 10% owner

Lim Richard J. · CIK 0001623720 · 10% owner

Paster Anne-Mari · CIK 0001652863 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 2,579,881 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: The Series A Convertible Preferred Stock ("Series A") converted automatically into shares of the issuer's common stock on a 1-for-9.94688 basis upon the completion of IPO. The Series A had no expiration date.

F3 · derivative.exercise_date: The Series A Convertible Preferred Stock ("Series A") converted automatically into shares of the issuer's common stock on a 1-for-9.94688 basis upon the completion of IPO. The Series A had no expiration date.

F3 · derivative.expiration_date: The Series A Convertible Preferred Stock ("Series A") converted automatically into shares of the issuer's common stock on a 1-for-9.94688 basis upon the completion of IPO. The Series A had no expiration date.

F1 · ownership.direct: The reported securities are beneficially owned by Omega Fund IV, L.P. ("Omega IV"). The reported securities may be deemed to be beneficially owned by each of Omega Fund IV GP, L.P. ("Omega IV GP"), as the general partner of Omega IV, and Omega Fund IV GP Manager, Ltd. ("Omega IV GP Manager"), as the general partner of Omega IV GP. Otello Stampacchia, Richard Lim and Anne-Mari Paster are all the shareholders and directors of Omega IV GP Manager and have shared voting and investment power over the shares held by Omega IV and, as a result, may each be deemed to beneficially own the reported securities. Otello Stampacchia is also a director of the issuer. Each of the Reporting Persons disclaims beneficial ownership of the reported securities, except to the extent of his, her or its pecuniary interest therein.

SEC source: 0000899243-18-020583 · doc4.xml · derivative · entry 7

Omega Fund IV, L.P. · CIK 0001528382 · 10% owner

Omega Fund IV GP, L.P. · CIK 0001528383 · 10% owner

Omega Fund IV G.P. Manager, Ltd. · CIK 0001624456 · 10% owner

Stampacchia Otello · CIK 0001361712 · Director · 10% owner

Lim Richard J. · CIK 0001623720 · 10% owner

Paster Anne-Mari · CIK 0001652863 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 994,688 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: The Series Seed Preferred Stock ("Series Seed") converted automatically into shares of the issuer's common stock on a 1-for-9.94688 basis upon the completion of the issuer's public offering of common stock pursuant the issuer's registration statement under the Securities Act of 1933, as amended, filed with the Commission on June 22, 2018, as subsequently amended (the "IPO"). The Series Seed had no expiration date.

F2 · derivative.exercise_date: The Series Seed Preferred Stock ("Series Seed") converted automatically into shares of the issuer's common stock on a 1-for-9.94688 basis upon the completion of the issuer's public offering of common stock pursuant the issuer's registration statement under the Securities Act of 1933, as amended, filed with the Commission on June 22, 2018, as subsequently amended (the "IPO"). The Series Seed had no expiration date.

F2 · derivative.expiration_date: The Series Seed Preferred Stock ("Series Seed") converted automatically into shares of the issuer's common stock on a 1-for-9.94688 basis upon the completion of the issuer's public offering of common stock pursuant the issuer's registration statement under the Securities Act of 1933, as amended, filed with the Commission on June 22, 2018, as subsequently amended (the "IPO"). The Series Seed had no expiration date.

F1 · ownership.direct: The reported securities are beneficially owned by Omega Fund IV, L.P. ("Omega IV"). The reported securities may be deemed to be beneficially owned by each of Omega Fund IV GP, L.P. ("Omega IV GP"), as the general partner of Omega IV, and Omega Fund IV GP Manager, Ltd. ("Omega IV GP Manager"), as the general partner of Omega IV GP. Otello Stampacchia, Richard Lim and Anne-Mari Paster are all the shareholders and directors of Omega IV GP Manager and have shared voting and investment power over the shares held by Omega IV and, as a result, may each be deemed to beneficially own the reported securities. Otello Stampacchia is also a director of the issuer. Each of the Reporting Persons disclaims beneficial ownership of the reported securities, except to the extent of his, her or its pecuniary interest therein.

SEC source: 0000899243-18-020583 · doc4.xml · derivative · entry 6

Omega Fund IV, L.P. · CIK 0001528382 · 10% owner

Omega Fund IV GP, L.P. · CIK 0001528383 · 10% owner

Omega Fund IV G.P. Manager, Ltd. · CIK 0001624456 · 10% owner

Stampacchia Otello · CIK 0001361712 · Director · 10% owner

Lim Richard J. · CIK 0001623720 · 10% owner

Paster Anne-Mari · CIK 0001652863 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 248,672

Underlying: Common Stock · 248,672 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.

F5 · derivative.exercise_price: The Series Seed Warrants (the "Seed Warrants") converted automatically in warrants to purchase shares of the issuer's common stock (the "Common Stock Warrants") on a 1-for-9.94688 basis upon the completion of IPO. The exercise price of the Common Stock Warrants is $1.01 per share of the issuer's common stock. The Seed Warrants had no expiration date and the Common Stock Warrants have no expiration date.

F5 · derivative.exercise_date: The Series Seed Warrants (the "Seed Warrants") converted automatically in warrants to purchase shares of the issuer's common stock (the "Common Stock Warrants") on a 1-for-9.94688 basis upon the completion of IPO. The exercise price of the Common Stock Warrants is $1.01 per share of the issuer's common stock. The Seed Warrants had no expiration date and the Common Stock Warrants have no expiration date.

F5 · derivative.expiration_date: The Series Seed Warrants (the "Seed Warrants") converted automatically in warrants to purchase shares of the issuer's common stock (the "Common Stock Warrants") on a 1-for-9.94688 basis upon the completion of IPO. The exercise price of the Common Stock Warrants is $1.01 per share of the issuer's common stock. The Seed Warrants had no expiration date and the Common Stock Warrants have no expiration date.

F1 · ownership.direct: The reported securities are beneficially owned by Omega Fund IV, L.P. ("Omega IV"). The reported securities may be deemed to be beneficially owned by each of Omega Fund IV GP, L.P. ("Omega IV GP"), as the general partner of Omega IV, and Omega Fund IV GP Manager, Ltd. ("Omega IV GP Manager"), as the general partner of Omega IV GP. Otello Stampacchia, Richard Lim and Anne-Mari Paster are all the shareholders and directors of Omega IV GP Manager and have shared voting and investment power over the shares held by Omega IV and, as a result, may each be deemed to beneficially own the reported securities. Otello Stampacchia is also a director of the issuer. Each of the Reporting Persons disclaims beneficial ownership of the reported securities, except to the extent of his, her or its pecuniary interest therein.

SEC source: 0000899243-18-020583 · doc4.xml · derivative · entry 5

Omega Fund IV, L.P. · CIK 0001528382 · 10% owner

Omega Fund IV GP, L.P. · CIK 0001528383 · 10% owner

Omega Fund IV G.P. Manager, Ltd. · CIK 0001624456 · 10% owner

Stampacchia Otello · CIK 0001361712 · Director · 10% owner

Lim Richard J. · CIK 0001623720 · 10% owner

Paster Anne-Mari · CIK 0001652863 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Series Seed Preferred Stock · 25,000 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.

F5 · derivative.exercise_price: The Series Seed Warrants (the "Seed Warrants") converted automatically in warrants to purchase shares of the issuer's common stock (the "Common Stock Warrants") on a 1-for-9.94688 basis upon the completion of IPO. The exercise price of the Common Stock Warrants is $1.01 per share of the issuer's common stock. The Seed Warrants had no expiration date and the Common Stock Warrants have no expiration date.

F5 · derivative.exercise_date: The Series Seed Warrants (the "Seed Warrants") converted automatically in warrants to purchase shares of the issuer's common stock (the "Common Stock Warrants") on a 1-for-9.94688 basis upon the completion of IPO. The exercise price of the Common Stock Warrants is $1.01 per share of the issuer's common stock. The Seed Warrants had no expiration date and the Common Stock Warrants have no expiration date.

F5 · derivative.expiration_date: The Series Seed Warrants (the "Seed Warrants") converted automatically in warrants to purchase shares of the issuer's common stock (the "Common Stock Warrants") on a 1-for-9.94688 basis upon the completion of IPO. The exercise price of the Common Stock Warrants is $1.01 per share of the issuer's common stock. The Seed Warrants had no expiration date and the Common Stock Warrants have no expiration date.

F5 · derivative.underlying_shares: The Series Seed Warrants (the "Seed Warrants") converted automatically in warrants to purchase shares of the issuer's common stock (the "Common Stock Warrants") on a 1-for-9.94688 basis upon the completion of IPO. The exercise price of the Common Stock Warrants is $1.01 per share of the issuer's common stock. The Seed Warrants had no expiration date and the Common Stock Warrants have no expiration date.

F1 · ownership.direct: The reported securities are beneficially owned by Omega Fund IV, L.P. ("Omega IV"). The reported securities may be deemed to be beneficially owned by each of Omega Fund IV GP, L.P. ("Omega IV GP"), as the general partner of Omega IV, and Omega Fund IV GP Manager, Ltd. ("Omega IV GP Manager"), as the general partner of Omega IV GP. Otello Stampacchia, Richard Lim and Anne-Mari Paster are all the shareholders and directors of Omega IV GP Manager and have shared voting and investment power over the shares held by Omega IV and, as a result, may each be deemed to beneficially own the reported securities. Otello Stampacchia is also a director of the issuer. Each of the Reporting Persons disclaims beneficial ownership of the reported securities, except to the extent of his, her or its pecuniary interest therein.

SEC source: 0000899243-18-020583 · doc4.xml · nonDerivative · entry 4

Omega Fund IV, L.P. · CIK 0001528382 · 10% owner

Omega Fund IV GP, L.P. · CIK 0001528383 · 10% owner

Omega Fund IV G.P. Manager, Ltd. · CIK 0001624456 · 10% owner

Stampacchia Otello · CIK 0001361712 · Director · 10% owner

Lim Richard J. · CIK 0001623720 · 10% owner

Paster Anne-Mari · CIK 0001652863 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 4,854,783

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

F4 · price: The Series B Convertible Preferred Stock ("Series B") converted automatically into shares of the issuer's common stock on a 1-for-9.94688 basis upon the completion of IPO. The Series B had no expiration date.

F1 · ownership.direct: The reported securities are beneficially owned by Omega Fund IV, L.P. ("Omega IV"). The reported securities may be deemed to be beneficially owned by each of Omega Fund IV GP, L.P. ("Omega IV GP"), as the general partner of Omega IV, and Omega Fund IV GP Manager, Ltd. ("Omega IV GP Manager"), as the general partner of Omega IV GP. Otello Stampacchia, Richard Lim and Anne-Mari Paster are all the shareholders and directors of Omega IV GP Manager and have shared voting and investment power over the shares held by Omega IV and, as a result, may each be deemed to beneficially own the reported securities. Otello Stampacchia is also a director of the issuer. Each of the Reporting Persons disclaims beneficial ownership of the reported securities, except to the extent of his, her or its pecuniary interest therein.

SEC source: 0000899243-18-020583 · doc4.xml · nonDerivative · entry 3

Omega Fund IV, L.P. · CIK 0001528382 · 10% owner

Omega Fund IV GP, L.P. · CIK 0001528383 · 10% owner

Omega Fund IV G.P. Manager, Ltd. · CIK 0001624456 · 10% owner

Stampacchia Otello · CIK 0001361712 · Director · 10% owner

Lim Richard J. · CIK 0001623720 · 10% owner

Paster Anne-Mari · CIK 0001652863 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 3,841,236

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 · price: The Series A Convertible Preferred Stock ("Series A") converted automatically into shares of the issuer's common stock on a 1-for-9.94688 basis upon the completion of IPO. The Series A had no expiration date.

F1 · ownership.direct: The reported securities are beneficially owned by Omega Fund IV, L.P. ("Omega IV"). The reported securities may be deemed to be beneficially owned by each of Omega Fund IV GP, L.P. ("Omega IV GP"), as the general partner of Omega IV, and Omega Fund IV GP Manager, Ltd. ("Omega IV GP Manager"), as the general partner of Omega IV GP. Otello Stampacchia, Richard Lim and Anne-Mari Paster are all the shareholders and directors of Omega IV GP Manager and have shared voting and investment power over the shares held by Omega IV and, as a result, may each be deemed to beneficially own the reported securities. Otello Stampacchia is also a director of the issuer. Each of the Reporting Persons disclaims beneficial ownership of the reported securities, except to the extent of his, her or its pecuniary interest therein.

SEC source: 0000899243-18-020583 · doc4.xml · nonDerivative · entry 2

Omega Fund IV, L.P. · CIK 0001528382 · 10% owner

Omega Fund IV GP, L.P. · CIK 0001528383 · 10% owner

Omega Fund IV G.P. Manager, Ltd. · CIK 0001624456 · 10% owner

Stampacchia Otello · CIK 0001361712 · Director · 10% owner

Lim Richard J. · CIK 0001623720 · 10% owner

Paster Anne-Mari · CIK 0001652863 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,261,355

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: The Series Seed Preferred Stock ("Series Seed") converted automatically into shares of the issuer's common stock on a 1-for-9.94688 basis upon the completion of the issuer's public offering of common stock pursuant the issuer's registration statement under the Securities Act of 1933, as amended, filed with the Commission on June 22, 2018, as subsequently amended (the "IPO"). The Series Seed had no expiration date.

F1 · ownership.direct: The reported securities are beneficially owned by Omega Fund IV, L.P. ("Omega IV"). The reported securities may be deemed to be beneficially owned by each of Omega Fund IV GP, L.P. ("Omega IV GP"), as the general partner of Omega IV, and Omega Fund IV GP Manager, Ltd. ("Omega IV GP Manager"), as the general partner of Omega IV GP. Otello Stampacchia, Richard Lim and Anne-Mari Paster are all the shareholders and directors of Omega IV GP Manager and have shared voting and investment power over the shares held by Omega IV and, as a result, may each be deemed to beneficially own the reported securities. Otello Stampacchia is also a director of the issuer. Each of the Reporting Persons disclaims beneficial ownership of the reported securities, except to the extent of his, her or its pecuniary interest therein.

SEC source: 0000899243-18-020583 · doc4.xml · nonDerivative · entry 1

Omega Fund IV, L.P. · CIK 0001528382 · 10% owner

Omega Fund IV GP, L.P. · CIK 0001528383 · 10% owner

Omega Fund IV G.P. Manager, Ltd. · CIK 0001624456 · 10% owner

Stampacchia Otello · CIK 0001361712 · Director · 10% owner

Lim Richard J. · CIK 0001623720 · 10% owner

Paster Anne-Mari · CIK 0001652863 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 266,667

F1 · ownership.direct: The reported securities are beneficially owned by Omega Fund IV, L.P. ("Omega IV"). The reported securities may be deemed to be beneficially owned by each of Omega Fund IV GP, L.P. ("Omega IV GP"), as the general partner of Omega IV, and Omega Fund IV GP Manager, Ltd. ("Omega IV GP Manager"), as the general partner of Omega IV GP. Otello Stampacchia, Richard Lim and Anne-Mari Paster are all the shareholders and directors of Omega IV GP Manager and have shared voting and investment power over the shares held by Omega IV and, as a result, may each be deemed to beneficially own the reported securities. Otello Stampacchia is also a director of the issuer. Each of the Reporting Persons disclaims beneficial ownership of the reported securities, except to the extent of his, her or its pecuniary interest therein.

SEC source: 0001144204-18-039736 · tv499206_4.xml · derivative · entry 2

Redmile Group, LLC · CIK 0001425738 · 10% owner

Green Jeremy · CIK 0001650527 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 0

Underlying: Common Stock · 779,655 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: The Series B Convertible Preferred Stock converted into shares of the Issuer's common stock immediately prior to the closing of the Issuer's initial public offering on a 1-for-9.94688 basis and had no expiration date.

F1 · derivative.exercise_date: The Series B Convertible Preferred Stock converted into shares of the Issuer's common stock immediately prior to the closing of the Issuer's initial public offering on a 1-for-9.94688 basis and had no expiration date.

F1 · derivative.expiration_date: The Series B Convertible Preferred Stock converted into shares of the Issuer's common stock immediately prior to the closing of the Issuer's initial public offering on a 1-for-9.94688 basis and had no expiration date.

F2 · ownership.nature: These securities are directly owned by certain private investment vehicles and separately managed accounts managed by Redmile Group, LLC ("Redmile") and may be deemed beneficially owned by Redmile as investment manager of such private investment vehicles and separately managed accounts. The reported securities may also be deemed beneficially owned by Jeremy Green as the principal of Redmile. The Reporting Persons disclaim beneficial ownership of the reported securities except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that such Reporting Persons are the beneficial owners of the securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose.

SEC source: 0001144204-18-039736 · tv499206_4.xml · nonDerivative · entry 1

Redmile Group, LLC · CIK 0001425738 · 10% owner

Green Jeremy · CIK 0001650527 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 779,655

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: The Series B Convertible Preferred Stock converted into shares of the Issuer's common stock immediately prior to the closing of the Issuer's initial public offering on a 1-for-9.94688 basis and had no expiration date.

F2 · ownership.nature: These securities are directly owned by certain private investment vehicles and separately managed accounts managed by Redmile Group, LLC ("Redmile") and may be deemed beneficially owned by Redmile as investment manager of such private investment vehicles and separately managed accounts. The reported securities may also be deemed beneficially owned by Jeremy Green as the principal of Redmile. The Reporting Persons disclaim beneficial ownership of the reported securities except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that such Reporting Persons are the beneficial owners of the securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose.

SEC source: 0001104659-18-047445 · a4.xml · derivative · entry 9

Forbion Capital Fund III Cooperatief U.A. · CIK 0001747586 · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 0

Underlying: Common Stock · 1,013,547 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: In connection with the completion of the Issuer's initial public offering, each share of the Issuer's series seed convertible preferred stock, series A convertible preferred stock and series B convertible preferred stock (collectively, the "Preferred Stock") converted into shares of the Issuer's common stock on a 1-for-9.94688 basis without payment or consideration. The Preferred Stock had no expiration date.

F4 · shares: Reflects the number of shares of applicable series of preferred stock held by the Reporting Person on an as-converted to common stock basis.

F1 · derivative.exercise_date: In connection with the completion of the Issuer's initial public offering, each share of the Issuer's series seed convertible preferred stock, series A convertible preferred stock and series B convertible preferred stock (collectively, the "Preferred Stock") converted into shares of the Issuer's common stock on a 1-for-9.94688 basis without payment or consideration. The Preferred Stock had no expiration date.

F1 · derivative.expiration_date: In connection with the completion of the Issuer's initial public offering, each share of the Issuer's series seed convertible preferred stock, series A convertible preferred stock and series B convertible preferred stock (collectively, the "Preferred Stock") converted into shares of the Issuer's common stock on a 1-for-9.94688 basis without payment or consideration. The Preferred Stock had no expiration date.

F4 · derivative.underlying_shares: Reflects the number of shares of applicable series of preferred stock held by the Reporting Person on an as-converted to common stock basis.

F2 · ownership.nature: The securities are held directly by Forbion Capital Fund III Cooperatief U.A. ("Forbion Coop"). Forbion III Management B.V. ("Forbion Management") is the director of Forbion Coop and may be deemed to have voting, investment and dispositive power with respect to the shares held by Forbion Coop. Forbion Management disclaims Section 16 beneficial ownership of the shares held by Forbion Coop, except to the extent, if any, of its pecuniary interest therein.

SEC source: 0001104659-18-047445 · a4.xml · derivative · entry 8

Forbion Capital Fund III Cooperatief U.A. · CIK 0001747586 · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 0

Underlying: Common Stock · 2,579,881 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: In connection with the completion of the Issuer's initial public offering, each share of the Issuer's series seed convertible preferred stock, series A convertible preferred stock and series B convertible preferred stock (collectively, the "Preferred Stock") converted into shares of the Issuer's common stock on a 1-for-9.94688 basis without payment or consideration. The Preferred Stock had no expiration date.

F4 · shares: Reflects the number of shares of applicable series of preferred stock held by the Reporting Person on an as-converted to common stock basis.

F1 · derivative.exercise_date: In connection with the completion of the Issuer's initial public offering, each share of the Issuer's series seed convertible preferred stock, series A convertible preferred stock and series B convertible preferred stock (collectively, the "Preferred Stock") converted into shares of the Issuer's common stock on a 1-for-9.94688 basis without payment or consideration. The Preferred Stock had no expiration date.

F1 · derivative.expiration_date: In connection with the completion of the Issuer's initial public offering, each share of the Issuer's series seed convertible preferred stock, series A convertible preferred stock and series B convertible preferred stock (collectively, the "Preferred Stock") converted into shares of the Issuer's common stock on a 1-for-9.94688 basis without payment or consideration. The Preferred Stock had no expiration date.

F4 · derivative.underlying_shares: Reflects the number of shares of applicable series of preferred stock held by the Reporting Person on an as-converted to common stock basis.

F2 · ownership.nature: The securities are held directly by Forbion Capital Fund III Cooperatief U.A. ("Forbion Coop"). Forbion III Management B.V. ("Forbion Management") is the director of Forbion Coop and may be deemed to have voting, investment and dispositive power with respect to the shares held by Forbion Coop. Forbion Management disclaims Section 16 beneficial ownership of the shares held by Forbion Coop, except to the extent, if any, of its pecuniary interest therein.

SEC source: 0001104659-18-047445 · a4.xml · derivative · entry 7

Forbion Capital Fund III Cooperatief U.A. · CIK 0001747586 · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 0

Underlying: Common Stock · 994,688 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: In connection with the completion of the Issuer's initial public offering, each share of the Issuer's series seed convertible preferred stock, series A convertible preferred stock and series B convertible preferred stock (collectively, the "Preferred Stock") converted into shares of the Issuer's common stock on a 1-for-9.94688 basis without payment or consideration. The Preferred Stock had no expiration date.

F4 · shares: Reflects the number of shares of applicable series of preferred stock held by the Reporting Person on an as-converted to common stock basis.

F1 · derivative.exercise_date: In connection with the completion of the Issuer's initial public offering, each share of the Issuer's series seed convertible preferred stock, series A convertible preferred stock and series B convertible preferred stock (collectively, the "Preferred Stock") converted into shares of the Issuer's common stock on a 1-for-9.94688 basis without payment or consideration. The Preferred Stock had no expiration date.

F1 · derivative.expiration_date: In connection with the completion of the Issuer's initial public offering, each share of the Issuer's series seed convertible preferred stock, series A convertible preferred stock and series B convertible preferred stock (collectively, the "Preferred Stock") converted into shares of the Issuer's common stock on a 1-for-9.94688 basis without payment or consideration. The Preferred Stock had no expiration date.

F4 · derivative.underlying_shares: Reflects the number of shares of applicable series of preferred stock held by the Reporting Person on an as-converted to common stock basis.

F2 · ownership.nature: The securities are held directly by Forbion Capital Fund III Cooperatief U.A. ("Forbion Coop"). Forbion III Management B.V. ("Forbion Management") is the director of Forbion Coop and may be deemed to have voting, investment and dispositive power with respect to the shares held by Forbion Coop. Forbion Management disclaims Section 16 beneficial ownership of the shares held by Forbion Coop, except to the extent, if any, of its pecuniary interest therein.

SEC source: 0001104659-18-047445 · a4.xml · derivative · entry 6

Forbion Capital Fund III Cooperatief U.A. · CIK 0001747586 · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 0

Underlying: Series Seed Convertible Preferred Stock · 248,672 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: Reflects warrants to acquire shares of the Issuer's Series Seed Convertible Preferred Stock which automatically converted into warrants to acquire shares of the Issuer's common stock immediately prior to the completion of the Issuer's initial public offering on a 1-for-9.94688 basis without payment or consideration. The warrants have no expiration date. The exercise price is $1.01 per share of the Issuer's common stock.

F4 · shares: Reflects the number of shares of applicable series of preferred stock held by the Reporting Person on an as-converted to common stock basis.

F3 · derivative.exercise_date: Reflects warrants to acquire shares of the Issuer's Series Seed Convertible Preferred Stock which automatically converted into warrants to acquire shares of the Issuer's common stock immediately prior to the completion of the Issuer's initial public offering on a 1-for-9.94688 basis without payment or consideration. The warrants have no expiration date. The exercise price is $1.01 per share of the Issuer's common stock.

F3 · derivative.expiration_date: Reflects warrants to acquire shares of the Issuer's Series Seed Convertible Preferred Stock which automatically converted into warrants to acquire shares of the Issuer's common stock immediately prior to the completion of the Issuer's initial public offering on a 1-for-9.94688 basis without payment or consideration. The warrants have no expiration date. The exercise price is $1.01 per share of the Issuer's common stock.

F4 · derivative.underlying_shares: Reflects the number of shares of applicable series of preferred stock held by the Reporting Person on an as-converted to common stock basis.

F2 · ownership.nature: The securities are held directly by Forbion Capital Fund III Cooperatief U.A. ("Forbion Coop"). Forbion III Management B.V. ("Forbion Management") is the director of Forbion Coop and may be deemed to have voting, investment and dispositive power with respect to the shares held by Forbion Coop. Forbion Management disclaims Section 16 beneficial ownership of the shares held by Forbion Coop, except to the extent, if any, of its pecuniary interest therein.

SEC source: 0001104659-18-047445 · a4.xml · derivative · entry 5

Forbion Capital Fund III Cooperatief U.A. · CIK 0001747586 · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 248,672

Underlying: Common Stock · 248,672 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: Reflects warrants to acquire shares of the Issuer's Series Seed Convertible Preferred Stock which automatically converted into warrants to acquire shares of the Issuer's common stock immediately prior to the completion of the Issuer's initial public offering on a 1-for-9.94688 basis without payment or consideration. The warrants have no expiration date. The exercise price is $1.01 per share of the Issuer's common stock.

F4 · shares: Reflects the number of shares of applicable series of preferred stock held by the Reporting Person on an as-converted to common stock basis.

F3 · derivative.exercise_date: Reflects warrants to acquire shares of the Issuer's Series Seed Convertible Preferred Stock which automatically converted into warrants to acquire shares of the Issuer's common stock immediately prior to the completion of the Issuer's initial public offering on a 1-for-9.94688 basis without payment or consideration. The warrants have no expiration date. The exercise price is $1.01 per share of the Issuer's common stock.

F3 · derivative.expiration_date: Reflects warrants to acquire shares of the Issuer's Series Seed Convertible Preferred Stock which automatically converted into warrants to acquire shares of the Issuer's common stock immediately prior to the completion of the Issuer's initial public offering on a 1-for-9.94688 basis without payment or consideration. The warrants have no expiration date. The exercise price is $1.01 per share of the Issuer's common stock.

F4 · derivative.underlying_shares: Reflects the number of shares of applicable series of preferred stock held by the Reporting Person on an as-converted to common stock basis.

F4 · balance_after: Reflects the number of shares of applicable series of preferred stock held by the Reporting Person on an as-converted to common stock basis.

F2 · ownership.nature: The securities are held directly by Forbion Capital Fund III Cooperatief U.A. ("Forbion Coop"). Forbion III Management B.V. ("Forbion Management") is the director of Forbion Coop and may be deemed to have voting, investment and dispositive power with respect to the shares held by Forbion Coop. Forbion Management disclaims Section 16 beneficial ownership of the shares held by Forbion Coop, except to the extent, if any, of its pecuniary interest therein.

SEC source: 0001104659-18-047445 · a4.xml · nonDerivative · entry 4

Forbion Capital Fund III Cooperatief U.A. · CIK 0001747586 · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 4,721,449

F2 · ownership.nature: The securities are held directly by Forbion Capital Fund III Cooperatief U.A. ("Forbion Coop"). Forbion III Management B.V. ("Forbion Management") is the director of Forbion Coop and may be deemed to have voting, investment and dispositive power with respect to the shares held by Forbion Coop. Forbion Management disclaims Section 16 beneficial ownership of the shares held by Forbion Coop, except to the extent, if any, of its pecuniary interest therein.

SEC source: 0001104659-18-047445 · a4.xml · nonDerivative · entry 3

Forbion Capital Fund III Cooperatief U.A. · CIK 0001747586 · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 4,588,116

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: In connection with the completion of the Issuer's initial public offering, each share of the Issuer's series seed convertible preferred stock, series A convertible preferred stock and series B convertible preferred stock (collectively, the "Preferred Stock") converted into shares of the Issuer's common stock on a 1-for-9.94688 basis without payment or consideration. The Preferred Stock had no expiration date.

F2 · ownership.nature: The securities are held directly by Forbion Capital Fund III Cooperatief U.A. ("Forbion Coop"). Forbion III Management B.V. ("Forbion Management") is the director of Forbion Coop and may be deemed to have voting, investment and dispositive power with respect to the shares held by Forbion Coop. Forbion Management disclaims Section 16 beneficial ownership of the shares held by Forbion Coop, except to the extent, if any, of its pecuniary interest therein.

SEC source: 0001104659-18-047445 · a4.xml · nonDerivative · entry 2

Forbion Capital Fund III Cooperatief U.A. · CIK 0001747586 · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 3,574,569

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: In connection with the completion of the Issuer's initial public offering, each share of the Issuer's series seed convertible preferred stock, series A convertible preferred stock and series B convertible preferred stock (collectively, the "Preferred Stock") converted into shares of the Issuer's common stock on a 1-for-9.94688 basis without payment or consideration. The Preferred Stock had no expiration date.

F2 · ownership.nature: The securities are held directly by Forbion Capital Fund III Cooperatief U.A. ("Forbion Coop"). Forbion III Management B.V. ("Forbion Management") is the director of Forbion Coop and may be deemed to have voting, investment and dispositive power with respect to the shares held by Forbion Coop. Forbion Management disclaims Section 16 beneficial ownership of the shares held by Forbion Coop, except to the extent, if any, of its pecuniary interest therein.

SEC source: 0001104659-18-047445 · a4.xml · nonDerivative · entry 1

Forbion Capital Fund III Cooperatief U.A. · CIK 0001747586 · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 994,688

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: In connection with the completion of the Issuer's initial public offering, each share of the Issuer's series seed convertible preferred stock, series A convertible preferred stock and series B convertible preferred stock (collectively, the "Preferred Stock") converted into shares of the Issuer's common stock on a 1-for-9.94688 basis without payment or consideration. The Preferred Stock had no expiration date.

F2 · ownership.nature: The securities are held directly by Forbion Capital Fund III Cooperatief U.A. ("Forbion Coop"). Forbion III Management B.V. ("Forbion Management") is the director of Forbion Coop and may be deemed to have voting, investment and dispositive power with respect to the shares held by Forbion Coop. Forbion Management disclaims Section 16 beneficial ownership of the shares held by Forbion Coop, except to the extent, if any, of its pecuniary interest therein.

SEC source: 0001104659-18-047456 · a4.xml · derivative · entry 1

Weinand Dieter · CIK 0001744419 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 27,000

Underlying: Common Stock · 27,000 shares

Expires 2028-07-19

F1 · derivative.exercise_date: This option was granted on July 19, 2018 subject to the completion of the Issuer's initial public offering, which closed on July 24, 2018. 25% of the shares underlying this stock option vest on July 19, 2019 and the remainder of the shares underlying this stock option vest in 24 equal monthly installments thereafter.

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: 0001104659-18-047457 · a4.xml · derivative · entry 4

Atlas Venture Fund X, L.P. · CIK 0001628098 · 10% owner

Atlas Venture Associates X, LLC · CIK 0001742765 · 10% owner

ATLAS VENTURE ASSOCIATES X, L.P. · CIK 0001742766 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 1,013,547 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: In connection with the closing of the Issuer's initial public offering, each share of the Issuer's series A convertible preferred stock and series B convertible preferred stock (collectively, the "Preferred Stock") converted into shares of the Issuer's common stock on a 1-for-9.94688 basis without payment or consideration. The Preferred Stock had no expiration date.

F3 · shares: Reflects the number of shares of Preferred Stock held by the Reporting Person on an as-converted to common stock basis.

F1 · derivative.exercise_date: In connection with the closing of the Issuer's initial public offering, each share of the Issuer's series A convertible preferred stock and series B convertible preferred stock (collectively, the "Preferred Stock") converted into shares of the Issuer's common stock on a 1-for-9.94688 basis without payment or consideration. The Preferred Stock had no expiration date.

F1 · derivative.expiration_date: In connection with the closing of the Issuer's initial public offering, each share of the Issuer's series A convertible preferred stock and series B convertible preferred stock (collectively, the "Preferred Stock") converted into shares of the Issuer's common stock on a 1-for-9.94688 basis without payment or consideration. The Preferred Stock had no expiration date.

F3 · derivative.underlying_shares: Reflects the number of shares of Preferred Stock held by the Reporting Person on an as-converted to common stock basis.

F2 · ownership.direct: The shares are held directly by Atlas Venture Fund X, L.P. ("Atlas Venture Fund X"). The general partner of Atlas Venture Fund X is Atlas Venture Associates X, L.P. ("AVA X LP"). Atlas Venture Associates X, LLC ("AVA X LLC") is the general partner of AVA X LP. Each of AVA X LP and AVA X LLC disclaims Section 16 beneficial ownership of the securities held by Atlas Venture Fund X, except to the extent of its pecuniary interest therein, if any.

SEC source: 0001104659-18-047457 · a4.xml · derivative · entry 3

Atlas Venture Fund X, L.P. · CIK 0001628098 · 10% owner

Atlas Venture Associates X, LLC · CIK 0001742765 · 10% owner

ATLAS VENTURE ASSOCIATES X, L.P. · CIK 0001742766 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 3,439,839 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: In connection with the closing of the Issuer's initial public offering, each share of the Issuer's series A convertible preferred stock and series B convertible preferred stock (collectively, the "Preferred Stock") converted into shares of the Issuer's common stock on a 1-for-9.94688 basis without payment or consideration. The Preferred Stock had no expiration date.

F3 · shares: Reflects the number of shares of Preferred Stock held by the Reporting Person on an as-converted to common stock basis.

F1 · derivative.exercise_date: In connection with the closing of the Issuer's initial public offering, each share of the Issuer's series A convertible preferred stock and series B convertible preferred stock (collectively, the "Preferred Stock") converted into shares of the Issuer's common stock on a 1-for-9.94688 basis without payment or consideration. The Preferred Stock had no expiration date.

F1 · derivative.expiration_date: In connection with the closing of the Issuer's initial public offering, each share of the Issuer's series A convertible preferred stock and series B convertible preferred stock (collectively, the "Preferred Stock") converted into shares of the Issuer's common stock on a 1-for-9.94688 basis without payment or consideration. The Preferred Stock had no expiration date.

F3 · derivative.underlying_shares: Reflects the number of shares of Preferred Stock held by the Reporting Person on an as-converted to common stock basis.

F2 · ownership.direct: The shares are held directly by Atlas Venture Fund X, L.P. ("Atlas Venture Fund X"). The general partner of Atlas Venture Fund X is Atlas Venture Associates X, L.P. ("AVA X LP"). Atlas Venture Associates X, LLC ("AVA X LLC") is the general partner of AVA X LP. Each of AVA X LP and AVA X LLC disclaims Section 16 beneficial ownership of the securities held by Atlas Venture Fund X, except to the extent of its pecuniary interest therein, if any.

SEC source: 0001104659-18-047457 · a4.xml · nonDerivative · entry 2

Atlas Venture Fund X, L.P. · CIK 0001628098 · 10% owner

Atlas Venture Associates X, LLC · CIK 0001742765 · 10% owner

ATLAS VENTURE ASSOCIATES X, L.P. · CIK 0001742766 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 4,453,386

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: In connection with the closing of the Issuer's initial public offering, each share of the Issuer's series A convertible preferred stock and series B convertible preferred stock (collectively, the "Preferred Stock") converted into shares of the Issuer's common stock on a 1-for-9.94688 basis without payment or consideration. The Preferred Stock had no expiration date.

F2 · ownership.direct: The shares are held directly by Atlas Venture Fund X, L.P. ("Atlas Venture Fund X"). The general partner of Atlas Venture Fund X is Atlas Venture Associates X, L.P. ("AVA X LP"). Atlas Venture Associates X, LLC ("AVA X LLC") is the general partner of AVA X LP. Each of AVA X LP and AVA X LLC disclaims Section 16 beneficial ownership of the securities held by Atlas Venture Fund X, except to the extent of its pecuniary interest therein, if any.

SEC source: 0001104659-18-047457 · a4.xml · nonDerivative · entry 1

Atlas Venture Fund X, L.P. · CIK 0001628098 · 10% owner

Atlas Venture Associates X, LLC · CIK 0001742765 · 10% owner

ATLAS VENTURE ASSOCIATES X, L.P. · CIK 0001742766 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 3,439,839

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: In connection with the closing of the Issuer's initial public offering, each share of the Issuer's series A convertible preferred stock and series B convertible preferred stock (collectively, the "Preferred Stock") converted into shares of the Issuer's common stock on a 1-for-9.94688 basis without payment or consideration. The Preferred Stock had no expiration date.

F2 · ownership.direct: The shares are held directly by Atlas Venture Fund X, L.P. ("Atlas Venture Fund X"). The general partner of Atlas Venture Fund X is Atlas Venture Associates X, L.P. ("AVA X LP"). Atlas Venture Associates X, LLC ("AVA X LLC") is the general partner of AVA X LP. Each of AVA X LP and AVA X LLC disclaims Section 16 beneficial ownership of the securities held by Atlas Venture Fund X, except to the extent of its pecuniary interest therein, if any.

SEC source: 0001104659-18-047458 · a4.xml · derivative · entry 1

Dhingra Kapil · CIK 0001456849 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 13,500

Underlying: Common Stock · 13,500 shares

Expires 2028-07-19

F1 · derivative.exercise_date: This option was granted on July 19, 2018 subject to the completion of the Issuer's initial public offering, which closed on July 24, 2018. 25% of the shares underlying this stock option vest on July 19, 2019 and the remainder of the shares underlying this stock option vest in 24 equal monthly installments thereafter.

SEC source: 0001104659-18-047459 · a4.xml · derivative · entry 1

Astley-Sparke Philip · CIK 0001376491 · Director · Executive Chairman

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 140,000

Underlying: Common Stock · 140,000 shares

Expires 2028-07-19

F1 · derivative.exercise_date: This option was granted on July 19, 2018 subject to the completion of the Issuer's initial public offering, which closed on July 24, 2018. 25% of the shares underlying this stock option vest on July 19, 2019 and the remainder of the shares underlying this stock option vest in 36 equal monthly installments thereafter.

SEC source: 0001104659-18-047452 · a4.xml · derivative · entry 1

GORGOL STEPHEN A · CIK 0001287980 · Chief Accounting Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 35,000

Underlying: Common Stock · 35,000 shares

Expires 2028-07-19

F1 · derivative.exercise_date: This option was granted on July 19, 2018 subject to the completion of the Issuer's initial public offering, which closed on July 24, 2018. 25% of the shares underlying this stock option vest on July 19, 2019 and the remainder of the shares underlying this stock option vest in 36 equal monthly installments thereafter.

SEC source: 0001104659-18-047446 · a4.xml · derivative · entry 2

SLATTERY JOSEPH P · CIK 0001246530 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 13,500

Underlying: Common Stock · 13,500 shares

Expires 2028-07-19

F1 · derivative.exercise_date: This option was granted on July 19, 2018 subject to the completion of the Issuer's initial public offering, which closed on July 24, 2018. 25% of the shares underlying this stock option vest on July 19, 2019 and the remainder of the shares underlying this stock option vest in 24 equal monthly installments thereafter.

SEC source: 0001104659-18-047446 · a4.xml · nonDerivative · entry 1

SLATTERY JOSEPH P · CIK 0001246530 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 6,667

SEC source: 0001104659-18-047454 · a4.xml · derivative · entry 1

Levitsky Hyam · CIK 0001375792 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 27,000

Underlying: Common Stock · 27,000 shares

Expires 2028-07-19

F1 · derivative.exercise_date: This option was granted on July 19, 2018 subject to the completion of the Issuer's initial public offering, which closed on July 24, 2018. 25% of the shares underlying this stock option vest on July 19, 2019 and the remainder of the shares underlying this stock option vest in 24 equal monthly installments thereafter.