REPL

SEC source: 0001104659-18-047451 · a4.xml · derivative · entry 1

Love Colin · CIK 0001376493 · Chief Operating Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 100,000

Underlying: Common Stock · 100,000 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: 0001104659-18-047447 · 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: 175,000

Underlying: Common Stock · 175,000 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: 0001104659-18-047449 · a4.xml · derivative · entry 5

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 2028-07-19

F4 · 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: 0001104659-18-047449 · a4.xml · derivative · entry 4

Rhodes Jason P · CIK 0001577014 · Director

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 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 series A convertible preferred stock or series B convertible preferred stock, as applicable 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 series A convertible preferred stock or series B convertible preferred stock, as applicable held by the Reporting Person on an as-converted to common stock basis.

F2 · ownership.nature: 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. The Reporting Person is a member of AVA X LLC and disclaims beneficial ownership of such securities held by Atlas Venture Fund X, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001104659-18-047449 · a4.xml · derivative · entry 3

Rhodes Jason P · CIK 0001577014 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

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 series A convertible preferred stock or series B convertible preferred stock, as applicable 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 series A convertible preferred stock or series B convertible preferred stock, as applicable held by the Reporting Person on an as-converted to common stock basis.

F2 · ownership.nature: 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. The Reporting Person is a member of AVA X LLC and disclaims beneficial ownership of such securities held by Atlas Venture Fund X, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001104659-18-047449 · a4.xml · nonDerivative · entry 2

Rhodes Jason P · CIK 0001577014 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

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.nature: 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. The Reporting Person is a member of AVA X LLC and disclaims beneficial ownership of such securities held by Atlas Venture Fund X, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001104659-18-047449 · a4.xml · nonDerivative · entry 1

Rhodes Jason P · CIK 0001577014 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

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.nature: 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. The Reporting Person is a member of AVA X LLC and disclaims beneficial ownership of such securities held by Atlas Venture Fund X, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001104659-18-047460 · a4.xml · derivative · entry 10

Slootweg Hugo Alexander · CIK 0001744922 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 13,500

Underlying: Common Stock · 13,500 shares

Expires 2028-07-19

F5 · 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: 0001104659-18-047460 · a4.xml · derivative · entry 9

Slootweg Hugo Alexander · CIK 0001744922 · Director · 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 the 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 the 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. The Reporting Person serves as one of the directors of Forbion Management and disclaims beneficial ownership over all shares of the Issuer for which Forbion Management may be deemed to beneficially own, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001104659-18-047460 · a4.xml · derivative · entry 8

Slootweg Hugo Alexander · CIK 0001744922 · Director · 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 the 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 the 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. The Reporting Person serves as one of the directors of Forbion Management and disclaims beneficial ownership over all shares of the Issuer for which Forbion Management may be deemed to beneficially own, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001104659-18-047460 · a4.xml · derivative · entry 7

Slootweg Hugo Alexander · CIK 0001744922 · Director · 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 the 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 the 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. The Reporting Person serves as one of the directors of Forbion Management and disclaims beneficial ownership over all shares of the Issuer for which Forbion Management may be deemed to beneficially own, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001104659-18-047460 · a4.xml · derivative · entry 6

Slootweg Hugo Alexander · CIK 0001744922 · Director · 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 the 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 the 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. The Reporting Person serves as one of the directors of Forbion Management and disclaims beneficial ownership over all shares of the Issuer for which Forbion Management may be deemed to beneficially own, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001104659-18-047460 · a4.xml · derivative · entry 5

Slootweg Hugo Alexander · CIK 0001744922 · Director · 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 the 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 the 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 the 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. The Reporting Person serves as one of the directors of Forbion Management and disclaims beneficial ownership over all shares of the Issuer for which Forbion Management may be deemed to beneficially own, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001104659-18-047460 · a4.xml · nonDerivative · entry 4

Slootweg Hugo Alexander · CIK 0001744922 · Director · 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. The Reporting Person serves as one of the directors of Forbion Management and disclaims beneficial ownership over all shares of the Issuer for which Forbion Management may be deemed to beneficially own, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001104659-18-047460 · a4.xml · nonDerivative · entry 3

Slootweg Hugo Alexander · CIK 0001744922 · Director · 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. The Reporting Person serves as one of the directors of Forbion Management and disclaims beneficial ownership over all shares of the Issuer for which Forbion Management may be deemed to beneficially own, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001104659-18-047460 · a4.xml · nonDerivative · entry 2

Slootweg Hugo Alexander · CIK 0001744922 · Director · 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. The Reporting Person serves as one of the directors of Forbion Management and disclaims beneficial ownership over all shares of the Issuer for which Forbion Management may be deemed to beneficially own, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001104659-18-047460 · a4.xml · nonDerivative · entry 1

Slootweg Hugo Alexander · CIK 0001744922 · Director · 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. The Reporting Person serves as one of the directors of Forbion Management and disclaims beneficial ownership over all shares of the Issuer for which Forbion Management may be deemed to beneficially own, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001104659-18-047455 · a4.xml · derivative · entry 1

Kaufman Howard · CIK 0001744424 · Chief Medical Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 150,000

Underlying: Common Stock · 150,000 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: 0001104659-18-047453 · a4.xml · derivative · entry 1

Esposito Pamela · CIK 0001744425 · Chief Business Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 70,000

Underlying: Common Stock · 70,000 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: 0000899243-18-020583 · doc4.xml · derivative · entry 10

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

F6 · derivative.exercise_date: The Common Stock Options (the "Options") were granted to Otello Stampacchia in his capacity as a director of the issuer on July 19, 2018 (the "Grant Date") contingent upon the closing of the IPO, with 25% of the Options vesting on the first anniversary of the Grant Date and an additional 3.125% of the Options vesting each month thereafter for 24 months. The Options expire on the tenth anniversary of the Grant Date.

F6 · derivative.expiration_date: The Common Stock Options (the "Options") were granted to Otello Stampacchia in his capacity as a director of the issuer on July 19, 2018 (the "Grant Date") contingent upon the closing of the IPO, with 25% of the Options vesting on the first anniversary of the Grant Date and an additional 3.125% of the Options vesting each month thereafter for 24 months. The Options expire on the tenth anniversary of the Grant Date.

F6 · balance_after: The Common Stock Options (the "Options") were granted to Otello Stampacchia in his capacity as a director of the issuer on July 19, 2018 (the "Grant Date") contingent upon the closing of the IPO, with 25% of the Options vesting on the first anniversary of the Grant Date and an additional 3.125% of the Options vesting each month thereafter for 24 months. The Options expire on the tenth anniversary of the Grant Date.

F6 · ownership.direct: The Common Stock Options (the "Options") were granted to Otello Stampacchia in his capacity as a director of the issuer on July 19, 2018 (the "Grant Date") contingent upon the closing of the IPO, with 25% of the Options vesting on the first anniversary of the Grant Date and an additional 3.125% of the Options vesting each month thereafter for 24 months. The Options expire on the tenth anniversary of the Grant Date.