DYN

SEC source: 0001209191-21-069428 · doc4.xml · derivative · entry 2

Scalzo Richard William · CIK 0001789545 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 25,044

Underlying: Common Stock · 25,044 shares

Expires 2031-12-09

F3 · derivative.exercise_date: This option was granted on December 10, 2021. The shares underlying the option are scheduled to vest over four years in equal monthly installments through December 10, 2025.

SEC source: 0001209191-21-069428 · doc4.xml · nonDerivative · entry 1

Scalzo Richard William · CIK 0001789545 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 27,302

F1 · shares: Consists of shares of Common Stock issuable under 16,696 restricted stock units ("RSUs"). Each RSU represents the right to receive one share of Common Stock upon vesting. These RSUs are scheduled to vest in equal quarterly installments over four years with the first installment vesting on March 10, 2022.

F2 · balance_after: Includes 25,295 unvested RSUs. Each unvested RSU represents the right to receive one share of Common Stock upon vesting.

SEC source: 0001209191-21-069425 · doc4.xml · derivative · entry 2

McNeill Jonathan · CIK 0001824673 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 37,967

Underlying: Common Stock · 37,967 shares

Expires 2031-12-09

F3 · derivative.exercise_date: This option was granted on December 10, 2021. The shares underlying the option are scheduled to vest over four years in equal monthly installments through December 10, 2025.

SEC source: 0001209191-21-069425 · doc4.xml · nonDerivative · entry 1

McNeill Jonathan · CIK 0001824673 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 60,947

F1 · shares: Consists of shares of Common Stock issuable under 25,311 restricted stock units ("RSUs"). Each RSU represents the right to receive one share of Common Stock upon vesting. These RSUs are scheduled to vest in equal quarterly installments over four years with the first installment vesting on March 10, 2022.

F2 · balance_after: Includes 38,070 unvested RSUs. Each unvested RSU represents the right to receive one share of Common Stock upon vesting.

SEC source: 0001209191-21-069423 · doc4.xml · derivative · entry 2

HIGH SUSANNA GATTI · CIK 0001691005 · Chief Operating Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 60,472

Underlying: Common Stock · 60,472 shares

Expires 2031-12-09

F3 · derivative.exercise_date: This option was granted on December 10, 2021. The shares underlying the option are scheduled to vest over four years in equal monthly installments through December 10, 2025.

SEC source: 0001209191-21-069423 · doc4.xml · nonDerivative · entry 1

HIGH SUSANNA GATTI · CIK 0001691005 · Chief Operating Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 73,768

F1 · shares: Consists of shares of Common Stock issuable under 40,315 restricted stock units ("RSUs"). Each RSU represents the right to receive one share of Common Stock upon vesting. These RSUs are scheduled to vest in equal quarterly installments over four years with the first installment vesting on March 10, 2022.

F2 · balance_after: Includes 67,243 unvested RSUs. Each unvested RSU represents the right to receive one share of Common Stock upon vesting.

SEC source: 0001209191-21-069420 · doc4.xml · derivative · entry 2

Brumm Joshua T · CIK 0001528826 · Director · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 177,285

Underlying: Common Stock · 177,285 shares

Expires 2031-12-09

F3 · derivative.exercise_date: This option was granted on December 10, 2021. The shares underlying the option are scheduled to vest over four years in equal monthly installments through December 10, 2025.

SEC source: 0001209191-21-069420 · doc4.xml · nonDerivative · entry 1

Brumm Joshua T · CIK 0001528826 · Director · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 213,708

F1 · shares: Consists of shares of Common Stock issuable under 118,190 restricted stock units ("RSUs"). Each RSU represents the right to receive one share of Common Stock upon vesting. These RSUs are scheduled to vest in equal quarterly installments over four years with the first installment vesting on March 10, 2022.

F2 · balance_after: Includes 198,460 unvested RSUs. Each unvested RSU represents the right to receive one share of Common Stock upon vesting.

SEC source: 0001209191-21-059052 · doc4.xml · nonDerivative · entry 1

Brumm Joshua T · CIK 0001528826 · Director · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 95,518

F1 · kind: This transaction was a charitable donation to a third party effective October 1, 2021 in which no value was received in return.

F2 · balance_after: Includes 80,270 unvested RSUs.

SEC source: 0001209191-21-057527 · doc4.xml · nonDerivative · entry 1

HIGH SUSANNA GATTI · CIK 0001691005 · Chief Operating Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 33,453

F1 · shares: Represents shares automatically sold by the Reporting Person to satisfy tax withholding obligations in connection with the vesting of restricted stock units granted to the Reporting Person on September 17, 2020. The automatic sale of the Reporting Person's shares is provided for in a restricted stock unit agreement constituting a "binding contract" consistent with the affirmative defense to liability under Rule 10b5-1 and the sale does not represent a discretionary trade by the Reporting Person.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices within the range of $17.17 to $17.30, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote of this Form 4.

F3 · balance_after: Includes 26,928 unvested RSUs.

SEC source: 0001209191-21-057323 · doc4.xml · nonDerivative · entry 2

Beskrovnaya Oxana · CIK 0001824542 · Chief Scientific Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 17,845

F1 · shares: Represents shares automatically sold by the Reporting Person to satisfy tax withholding obligations in connection with the vesting of restricted stock units granted to the Reporting Person on September 17, 2020. The automatic sale of the Reporting Person's shares is provided for in a restricted stock unit agreement constituting a "binding contract" consistent with the affirmative defense to liability under Rule 10b5-1 and the sale does not represent a discretionary trade by the Reporting Person.

F4 · price: The price reported in Column 4 is a weighted average price that represents the price of all shares sold by a broker on September 21, 2021 on behalf of a group of employees of the issuer to satisfy tax withholding obligations. These shares were sold in multiple transactions at prices within the range of $15.87 to $16.36, inclusive.

F3 · balance_after: Includes 14,467 unvested RSUs.

SEC source: 0001209191-21-057326 · doc4.xml · nonDerivative · entry 2

Scalzo Richard William · CIK 0001789545 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 10,606

F1 · shares: Represents shares automatically sold by the Reporting Person to satisfy tax withholding obligations in connection with the vesting of restricted stock units granted to the Reporting Person on September 17, 2020. The automatic sale of the Reporting Person's shares is provided for in a restricted stock unit agreement constituting a "binding contract" consistent with the affirmative defense to liability under Rule 10b5-1 and the sale does not represent a discretionary trade by the Reporting Person.

F4 · price: The price reported in Column 4 is a weighted average price that represents the price of all shares sold by a broker on September 21, 2021 on behalf of a group of employees of the issuer to satisfy tax withholding obligations. These shares were sold in multiple transactions at prices within the range of $15.87 to $16.36, inclusive.

F3 · balance_after: Includes 8,599 unvested RSUs.

SEC source: 0001209191-21-057325 · doc4.xml · nonDerivative · entry 2

McNeill Jonathan · CIK 0001824673 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 35,636

F1 · shares: Represents shares automatically sold by the Reporting Person to satisfy tax withholding obligations in connection with the vesting of restricted stock units granted to the Reporting Person on September 17, 2020. The automatic sale of the Reporting Person's shares is provided for in a restricted stock unit agreement constituting a "binding contract" consistent with the affirmative defense to liability under Rule 10b5-1 and the sale does not represent a discretionary trade by the Reporting Person.

F4 · price: The price reported in Column 4 is a weighted average price that represents the price of all shares sold by a broker on September 21, 2021 on behalf of a group of employees of the issuer to satisfy tax withholding obligations. These shares were sold in multiple transactions at prices within the range of $15.87 to $16.36, inclusive.

F3 · balance_after: Includes 12,759 unvested RSUs.

SEC source: 0001209191-21-057324 · doc4.xml · nonDerivative · entry 2

Brumm Joshua T · CIK 0001528826 · Director · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 99,018

F1 · shares: Represents shares automatically sold by the Reporting Person to satisfy tax withholding obligations in connection with the vesting of restricted stock units granted to the Reporting Person on September 17, 2020. The automatic sale of the Reporting Person's shares is provided for in a restricted stock unit agreement constituting a "binding contract" consistent with the affirmative defense to liability under Rule 10b5-1 and the sale does not represent a discretionary trade by the Reporting Person.

F4 · price: The price reported in Column 4 is a weighted average price that represents the price of all shares sold by a broker on September 21, 2021 on behalf of a group of employees of the issuer to satisfy tax withholding obligations. These shares were sold in multiple transactions at prices within the range of $15.87 to $16.36, inclusive.

F3 · balance_after: Includes 80,270 unvested RSUs.

SEC source: 0001209191-21-057323 · doc4.xml · nonDerivative · entry 1

Beskrovnaya Oxana · CIK 0001824542 · Chief Scientific Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 18,672

F1 · shares: Represents shares automatically sold by the Reporting Person to satisfy tax withholding obligations in connection with the vesting of restricted stock units granted to the Reporting Person on September 17, 2020. The automatic sale of the Reporting Person's shares is provided for in a restricted stock unit agreement constituting a "binding contract" consistent with the affirmative defense to liability under Rule 10b5-1 and the sale does not represent a discretionary trade by the Reporting Person.

F2 · price: The price reported in Column 4 is a weighted average price that represents the price of all shares sold by a broker on September 20, 2021 on behalf of a group of employees of the issuer to satisfy tax withholding obligations. These shares were sold in multiple transactions at prices within the range of $15.22 to $16.01, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range(s) set forth in footnote (2) and (4) of this Form 4.

F3 · balance_after: Includes 14,467 unvested RSUs.

SEC source: 0001209191-21-057326 · doc4.xml · nonDerivative · entry 1

Scalzo Richard William · CIK 0001789545 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 11,098

F1 · shares: Represents shares automatically sold by the Reporting Person to satisfy tax withholding obligations in connection with the vesting of restricted stock units granted to the Reporting Person on September 17, 2020. The automatic sale of the Reporting Person's shares is provided for in a restricted stock unit agreement constituting a "binding contract" consistent with the affirmative defense to liability under Rule 10b5-1 and the sale does not represent a discretionary trade by the Reporting Person.

F2 · price: The price reported in Column 4 is a weighted average price that represents the price of all shares sold by a broker on September 20, 2021 on behalf of a group of employees of the issuer to satisfy tax withholding obligations. These shares were sold in multiple transactions at prices within the range of $15.22 to $16.01, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range(s) set forth in footnote (2) and (4) of this Form 4.

F3 · balance_after: Includes 8,599 unvested RSUs.

SEC source: 0001209191-21-057325 · doc4.xml · nonDerivative · entry 1

McNeill Jonathan · CIK 0001824673 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 36,365

F1 · shares: Represents shares automatically sold by the Reporting Person to satisfy tax withholding obligations in connection with the vesting of restricted stock units granted to the Reporting Person on September 17, 2020. The automatic sale of the Reporting Person's shares is provided for in a restricted stock unit agreement constituting a "binding contract" consistent with the affirmative defense to liability under Rule 10b5-1 and the sale does not represent a discretionary trade by the Reporting Person.

F2 · price: The price reported in Column 4 is a weighted average price that represents the price of all shares sold by a broker on September 20, 2021 on behalf of a group of employees of the issuer to satisfy tax withholding obligations. These shares were sold in multiple transactions at prices within the range of $15.22 to $16.01, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range(s) set forth in footnote (2) and (4) of this Form 4.

F3 · balance_after: Includes 12,759 unvested RSUs.

SEC source: 0001209191-21-057324 · doc4.xml · nonDerivative · entry 1

Brumm Joshua T · CIK 0001528826 · Director · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 103,602

F1 · shares: Represents shares automatically sold by the Reporting Person to satisfy tax withholding obligations in connection with the vesting of restricted stock units granted to the Reporting Person on September 17, 2020. The automatic sale of the Reporting Person's shares is provided for in a restricted stock unit agreement constituting a "binding contract" consistent with the affirmative defense to liability under Rule 10b5-1 and the sale does not represent a discretionary trade by the Reporting Person.

F2 · price: The price reported in Column 4 is a weighted average price that represents the price of all shares sold by a broker on September 20, 2021 on behalf of a group of employees of the issuer to satisfy tax withholding obligations. These shares were sold in multiple transactions at prices within the range of $15.22 to $16.01, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range(s) set forth in footnote (2) and (4) of this Form 4.

F3 · balance_after: Includes 80,270 unvested RSUs.

SEC source: 0001209191-21-046784 · doc4.xml · nonDerivative · entry 1

Atlas Venture Fund XI, L.P. · CIK 0001708269 · 10% owner

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 7,326,117

F1 · kind: Represents a pro rata distribution, and not a purchase or sale of securities, by Atlas Venture Fund XI, L.P. ("Atlas Venture Fund XI") to its general partner and limited partners without additional consideration. This distribution was effected pursuant to a plan adopted by Atlas Venture Fund XI pursuant to Rule 10b5-1 on June 11, 2021.

SEC source: 0001209191-21-046494 · doc4.xml · derivative · entry 1

McNeill Jonathan · CIK 0001824673 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 25,000

Underlying: Common Stock · 25,000 shares

Expires 2031-07-09

F1 · derivative.exercise_date: This option was granted on July 10, 2021. The shares underlying the option are scheduled to vest over four years in equal quarterly installments from July 1, 2021.

SEC source: 0000899243-21-021642 · doc4.xml · derivative · entry 1

Beskrovnaya Oxana · CIK 0001824542 · Chief Scientific Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 110,000

Underlying: Common Stock · 110,000 shares

Expires 2031-06-01

F1 · derivative.exercise_date: This option was granted on June 2, 2021. The shares underlying the option are scheduled to vest over four years, with 25% of the shares vesting on June 2, 2022 and the remaining shares vesting in equal quarterly installments thereafter.

SEC source: 0000899243-21-020992 · doc4.xml · derivative · entry 1

Stehman-Breen Catherine · CIK 0001702233 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 19,596

Underlying: Common Stock · 19,596 shares

Expires 2031-05-25

F1 · derivative.exercise_date: This option was granted on May 26, 2021. The shares underlying the option are scheduled to vest in full on the earlier of (i) May 26, 2022 or (ii) the date of the Issuer's 2022 Annual Meeting of Stockholders

SEC source: 0000899243-21-020990 · doc4.xml · derivative · entry 1

Kersten Dirk · CIK 0001823682 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 19,596

Underlying: Common Stock · 19,596 shares

Expires 2031-05-25

F1 · derivative.exercise_date: This option was granted on May 26, 2021. The shares underlying the option are scheduled to vest in full on the earlier of (i) May 26, 2022 or (ii) the date of the Issuer's 2022 Annual Meeting of Stockholders

SEC source: 0000899243-21-020989 · doc4.xml · derivative · entry 1

Klein Lawrence Otto · CIK 0001762583 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 19,596

Underlying: Common Stock · 19,596 shares

Expires 2031-05-25

F1 · derivative.exercise_date: This option was granted on May 26, 2021. The shares underlying the option are scheduled to vest in full on the earlier of (i) May 26, 2022 or (ii) the date of the Issuer's 2022 Annual Meeting of Stockholders

SEC source: 0000899243-21-020988 · doc4.xml · derivative · entry 1

HURWITZ EDWARD · CIK 0001211840 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 19,596

Underlying: Common Stock · 19,596 shares

Expires 2031-05-25

F1 · derivative.exercise_date: This option was granted on May 26, 2021. The shares underlying the option are scheduled to vest in full on the earlier of (i) May 26, 2022 or (ii) the date of the Issuer's 2022 Annual Meeting of Stockholders

SEC source: 0000899243-21-020987 · doc4.xml · derivative · entry 1

Rhodes Jason P · CIK 0001577014 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 19,596

Underlying: Common Stock · 19,596 shares

Expires 2031-05-25

F1 · derivative.exercise_date: This option was granted on May 26, 2021. The shares underlying the option are scheduled to vest in full on the earlier of (i) May 26, 2022 or (ii) the date of the Issuer's 2022 Annual Meeting of Stockholders

F2 · ownership.direct: The Reporting Person is a member of Atlas Venture Associates XI, 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: 0000899243-21-020985 · doc4.xml · derivative · entry 1

Lubner David Charles · CIK 0001572000 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 19,596

Underlying: Common Stock · 19,596 shares

Expires 2031-05-25

F1 · derivative.exercise_date: This option was granted on May 26, 2021. The shares underlying the option are scheduled to vest in full on the earlier of (i) May 26, 2022 or (ii) the date of the Issuer's 2022 Annual Meeting of Stockholders

SEC source: 0000899243-21-009963 · doc4.xml · derivative · entry 2

Farwell Wildon · CIK 0001847941 · Chief Medical Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 250,000

Underlying: Common Stock · 250,000 shares

Expires 2031-03-01

F2 · derivative.exercise_date: This option was granted on March 2, 2021. The shares underlying the option are scheduled to vest over four years, with 25% of the shares vesting on March 1, 2022 and the remaining shares vesting in equal quarterly installments thereafter.

SEC source: 0000899243-21-009963 · doc4.xml · nonDerivative · entry 1

Farwell Wildon · CIK 0001847941 · Chief Medical Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 50,000

F1 · shares: Consists of shares of Common Stock issuable under 50,000 restricted stock units ("RSUs"). Each RSU represents the right to receive one share of Common Stock upon vesting. These RSUs are scheduled to vest in equal annual installments over four years with the first installment vesting on March 1, 2022.

SEC source: 0000899243-20-026194 · doc4.xml · derivative · entry 9

MPM BIOVENTURES 2018, L.P. · CIK 0001729505 · 10% owner

MPM BIOVENTURES 2018 (B), L.P. · CIK 0001729504 · 10% owner

MPM ASSET MANAGEMENT INVESTORS BV2018 LLC · CIK 0001734817 · 10% owner

MPM BioVentures 2018 GP LLC · CIK 0001818701 · 10% owner

MPM BioVentures 2018 LLC · CIK 0001818702 · 10% owner

EVNIN LUKE · CIK 0001134657 · 10% owner

Foley Todd · CIK 0001473930 · 10% owner

GADICKE ANSBERT · CIK 0001134655 · 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 · 7,893 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: On September 21, 2020, the Series B Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

F5 · derivative.exercise_date: On September 21, 2020, the Series B Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

F5 · derivative.expiration_date: On September 21, 2020, the Series B Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

F4 · ownership.nature: The shares are held directly by MPM Asset Management Investors BV2018 LLC ("MPM Asset Management"). The manager of MPM Asset Management is BV 2018 LLC. Edward Hurwitz, Luke Evnin, Ansbert Gadicke, and Todd Foley are the Managing Directors of BV2018 LLC. Each of BV 2018 LLC, Edward Hurwitz, Luke Evnin, Ansbert Gadicke, and Todd Foley disclaims Section 16 beneficial ownership of the securities held by MPM Asset Management, except to the extent of his pecuniary interest therein, if any.

SEC source: 0000899243-20-026194 · doc4.xml · derivative · entry 8

MPM BIOVENTURES 2018, L.P. · CIK 0001729505 · 10% owner

MPM BIOVENTURES 2018 (B), L.P. · CIK 0001729504 · 10% owner

MPM ASSET MANAGEMENT INVESTORS BV2018 LLC · CIK 0001734817 · 10% owner

MPM BioVentures 2018 GP LLC · CIK 0001818701 · 10% owner

MPM BioVentures 2018 LLC · CIK 0001818702 · 10% owner

EVNIN LUKE · CIK 0001134657 · 10% owner

Foley Todd · CIK 0001473930 · 10% owner

GADICKE ANSBERT · CIK 0001134655 · 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 · 21,254 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: On September 21, 2020, the Series B Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

F5 · derivative.exercise_date: On September 21, 2020, the Series B Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

F5 · derivative.expiration_date: On September 21, 2020, the Series B Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

F3 · ownership.nature: The shares are held directly by MPM BioVentures 2018 (B), L.P. ("BV 2018(B)"). The general partner of BV 2018(B) is BV 2018 GP. BV 2018 LLC is the managing member of BV 2018 GP. Edward Hurwitz, Luke Evnin, Ansbert Gadicke, and Todd Foley are the Managing Directors of BV 2018 LLC. Each of BV 2018 GP, BV 2018 LLC, Edward Hurwitz, Luke Evnin, Ansbert Gadicke, and Todd Foley disclaims Section 16 beneficial ownership of the securities held by BV 2018(B), except to the extent of its pecuniary interest therein, if any.

SEC source: 0000899243-20-026194 · doc4.xml · derivative · entry 7

MPM BIOVENTURES 2018, L.P. · CIK 0001729505 · 10% owner

MPM BIOVENTURES 2018 (B), L.P. · CIK 0001729504 · 10% owner

MPM ASSET MANAGEMENT INVESTORS BV2018 LLC · CIK 0001734817 · 10% owner

MPM BioVentures 2018 GP LLC · CIK 0001818701 · 10% owner

MPM BioVentures 2018 LLC · CIK 0001818702 · 10% owner

EVNIN LUKE · CIK 0001134657 · 10% owner

Foley Todd · CIK 0001473930 · 10% owner

GADICKE ANSBERT · CIK 0001134655 · 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 · 399,867 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: On September 21, 2020, the Series B Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

F5 · derivative.exercise_date: On September 21, 2020, the Series B Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

F5 · derivative.expiration_date: On September 21, 2020, the Series B Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

F2 · ownership.nature: The shares are held directly by MPM BioVentures 2018, L.P. ("BV 2018"). The general partner of BV 2018 is MPM BioVentures 2018 GP LLC ("BV 2018 GP"). MPM BioVentures 2018 LLC ("BV 2018 LLC") is the managing member of BV 2018 GP. Edward Hurwitz, Luke Evnin, Ansbert Gadicke, and Todd Foley are the Managing Directors of BV 2018 LLC. Each of BV 2018 GP, BV 2018 LLC, Edward Hurwitz, Luke Evnin, Ansbert Gadicke, and Todd Foley disclaims Section 16 beneficial ownership of the securities held by BV 2018, except to the extent of its pecuniary interest therein, if any.

SEC source: 0000899243-20-026194 · doc4.xml · derivative · entry 6

MPM BIOVENTURES 2018, L.P. · CIK 0001729505 · 10% owner

MPM BIOVENTURES 2018 (B), L.P. · CIK 0001729504 · 10% owner

MPM ASSET MANAGEMENT INVESTORS BV2018 LLC · CIK 0001734817 · 10% owner

MPM BioVentures 2018 GP LLC · CIK 0001818701 · 10% owner

MPM BioVentures 2018 LLC · CIK 0001818702 · 10% owner

EVNIN LUKE · CIK 0001134657 · 10% owner

Foley Todd · CIK 0001473930 · 10% owner

GADICKE ANSBERT · CIK 0001134655 · 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 · 83,188 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: On September 21, 2020, the Series A Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

F1 · derivative.exercise_date: On September 21, 2020, the Series A Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

F1 · derivative.expiration_date: On September 21, 2020, the Series A Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

F4 · ownership.nature: The shares are held directly by MPM Asset Management Investors BV2018 LLC ("MPM Asset Management"). The manager of MPM Asset Management is BV 2018 LLC. Edward Hurwitz, Luke Evnin, Ansbert Gadicke, and Todd Foley are the Managing Directors of BV2018 LLC. Each of BV 2018 LLC, Edward Hurwitz, Luke Evnin, Ansbert Gadicke, and Todd Foley disclaims Section 16 beneficial ownership of the securities held by MPM Asset Management, except to the extent of his pecuniary interest therein, if any.

SEC source: 0000899243-20-026194 · doc4.xml · derivative · entry 5

MPM BIOVENTURES 2018, L.P. · CIK 0001729505 · 10% owner

MPM BIOVENTURES 2018 (B), L.P. · CIK 0001729504 · 10% owner

MPM ASSET MANAGEMENT INVESTORS BV2018 LLC · CIK 0001734817 · 10% owner

MPM BioVentures 2018 GP LLC · CIK 0001818701 · 10% owner

MPM BioVentures 2018 LLC · CIK 0001818702 · 10% owner

EVNIN LUKE · CIK 0001134657 · 10% owner

Foley Todd · CIK 0001473930 · 10% owner

GADICKE ANSBERT · CIK 0001134655 · 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 · 224,025 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: On September 21, 2020, the Series A Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

F1 · derivative.exercise_date: On September 21, 2020, the Series A Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

F1 · derivative.expiration_date: On September 21, 2020, the Series A Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

F3 · ownership.nature: The shares are held directly by MPM BioVentures 2018 (B), L.P. ("BV 2018(B)"). The general partner of BV 2018(B) is BV 2018 GP. BV 2018 LLC is the managing member of BV 2018 GP. Edward Hurwitz, Luke Evnin, Ansbert Gadicke, and Todd Foley are the Managing Directors of BV 2018 LLC. Each of BV 2018 GP, BV 2018 LLC, Edward Hurwitz, Luke Evnin, Ansbert Gadicke, and Todd Foley disclaims Section 16 beneficial ownership of the securities held by BV 2018(B), except to the extent of its pecuniary interest therein, if any.

SEC source: 0000899243-20-026194 · doc4.xml · derivative · entry 4

MPM BIOVENTURES 2018, L.P. · CIK 0001729505 · 10% owner

MPM BIOVENTURES 2018 (B), L.P. · CIK 0001729504 · 10% owner

MPM ASSET MANAGEMENT INVESTORS BV2018 LLC · CIK 0001734817 · 10% owner

MPM BioVentures 2018 GP LLC · CIK 0001818701 · 10% owner

MPM BioVentures 2018 LLC · CIK 0001818702 · 10% owner

EVNIN LUKE · CIK 0001134657 · 10% owner

Foley Todd · CIK 0001473930 · 10% owner

GADICKE ANSBERT · CIK 0001134655 · 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 · 4,215,076 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: On September 21, 2020, the Series A Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

F1 · derivative.exercise_date: On September 21, 2020, the Series A Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

F1 · derivative.expiration_date: On September 21, 2020, the Series A Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

F2 · ownership.nature: The shares are held directly by MPM BioVentures 2018, L.P. ("BV 2018"). The general partner of BV 2018 is MPM BioVentures 2018 GP LLC ("BV 2018 GP"). MPM BioVentures 2018 LLC ("BV 2018 LLC") is the managing member of BV 2018 GP. Edward Hurwitz, Luke Evnin, Ansbert Gadicke, and Todd Foley are the Managing Directors of BV 2018 LLC. Each of BV 2018 GP, BV 2018 LLC, Edward Hurwitz, Luke Evnin, Ansbert Gadicke, and Todd Foley disclaims Section 16 beneficial ownership of the securities held by BV 2018, except to the extent of its pecuniary interest therein, if any.

SEC source: 0000899243-20-026194 · doc4.xml · nonDerivative · entry 3

MPM BIOVENTURES 2018, L.P. · CIK 0001729505 · 10% owner

MPM BIOVENTURES 2018 (B), L.P. · CIK 0001729504 · 10% owner

MPM ASSET MANAGEMENT INVESTORS BV2018 LLC · CIK 0001734817 · 10% owner

MPM BioVentures 2018 GP LLC · CIK 0001818701 · 10% owner

MPM BioVentures 2018 LLC · CIK 0001818702 · 10% owner

EVNIN LUKE · CIK 0001134657 · 10% owner

Foley Todd · CIK 0001473930 · 10% owner

GADICKE ANSBERT · CIK 0001134655 · 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: 91,081

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: On September 21, 2020, the Series A Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

F5 · price: On September 21, 2020, the Series B Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

F4 · ownership.nature: The shares are held directly by MPM Asset Management Investors BV2018 LLC ("MPM Asset Management"). The manager of MPM Asset Management is BV 2018 LLC. Edward Hurwitz, Luke Evnin, Ansbert Gadicke, and Todd Foley are the Managing Directors of BV2018 LLC. Each of BV 2018 LLC, Edward Hurwitz, Luke Evnin, Ansbert Gadicke, and Todd Foley disclaims Section 16 beneficial ownership of the securities held by MPM Asset Management, except to the extent of his pecuniary interest therein, if any.

SEC source: 0000899243-20-026194 · doc4.xml · nonDerivative · entry 2

MPM BIOVENTURES 2018, L.P. · CIK 0001729505 · 10% owner

MPM BIOVENTURES 2018 (B), L.P. · CIK 0001729504 · 10% owner

MPM ASSET MANAGEMENT INVESTORS BV2018 LLC · CIK 0001734817 · 10% owner

MPM BioVentures 2018 GP LLC · CIK 0001818701 · 10% owner

MPM BioVentures 2018 LLC · CIK 0001818702 · 10% owner

EVNIN LUKE · CIK 0001134657 · 10% owner

Foley Todd · CIK 0001473930 · 10% owner

GADICKE ANSBERT · CIK 0001134655 · 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: 245,279

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: On September 21, 2020, the Series A Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

F5 · price: On September 21, 2020, the Series B Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

F3 · ownership.nature: The shares are held directly by MPM BioVentures 2018 (B), L.P. ("BV 2018(B)"). The general partner of BV 2018(B) is BV 2018 GP. BV 2018 LLC is the managing member of BV 2018 GP. Edward Hurwitz, Luke Evnin, Ansbert Gadicke, and Todd Foley are the Managing Directors of BV 2018 LLC. Each of BV 2018 GP, BV 2018 LLC, Edward Hurwitz, Luke Evnin, Ansbert Gadicke, and Todd Foley disclaims Section 16 beneficial ownership of the securities held by BV 2018(B), except to the extent of its pecuniary interest therein, if any.

SEC source: 0000899243-20-026194 · doc4.xml · nonDerivative · entry 1

MPM BIOVENTURES 2018, L.P. · CIK 0001729505 · 10% owner

MPM BIOVENTURES 2018 (B), L.P. · CIK 0001729504 · 10% owner

MPM ASSET MANAGEMENT INVESTORS BV2018 LLC · CIK 0001734817 · 10% owner

MPM BioVentures 2018 GP LLC · CIK 0001818701 · 10% owner

MPM BioVentures 2018 LLC · CIK 0001818702 · 10% owner

EVNIN LUKE · CIK 0001134657 · 10% owner

Foley Todd · CIK 0001473930 · 10% owner

GADICKE ANSBERT · CIK 0001134655 · 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: 4,614,943

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: On September 21, 2020, the Series A Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

F5 · price: On September 21, 2020, the Series B Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

F2 · ownership.nature: The shares are held directly by MPM BioVentures 2018, L.P. ("BV 2018"). The general partner of BV 2018 is MPM BioVentures 2018 GP LLC ("BV 2018 GP"). MPM BioVentures 2018 LLC ("BV 2018 LLC") is the managing member of BV 2018 GP. Edward Hurwitz, Luke Evnin, Ansbert Gadicke, and Todd Foley are the Managing Directors of BV 2018 LLC. Each of BV 2018 GP, BV 2018 LLC, Edward Hurwitz, Luke Evnin, Ansbert Gadicke, and Todd Foley disclaims Section 16 beneficial ownership of the securities held by BV 2018, except to the extent of its pecuniary interest therein, if any.

SEC source: 0000899243-20-026193 · doc4.xml · derivative · entry 6

VV Manager II, LLC · CIK 0001824569 · 10% owner

Vida Ventures II, LLC · CIK 0001776851 · 10% owner

VIDA VENTURES II-A, LLC · CIK 0001781930 · 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 · 57,916 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: On September 21, 2020, the Series B Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

F1 · derivative.exercise_date: On September 21, 2020, the Series B Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

F1 · derivative.expiration_date: On September 21, 2020, the Series B Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

F4 · ownership.nature: The shares are held directly by Vida Ventures II-A, LLC ("Vida II-A"). VV Manager II is the manager of Vida II-A. Each of the Management Committee ,the Investment Committee and the respective members thereof may be deemed to share voting and dispositive power over the shares held by Vida II-A. VV Manager II, the Management Committee, the Investment Committee and each member of each of the Management Committee and Investment Committee disclaims beneficial ownership over the securities held of record by Vida II-A and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interest therein.

SEC source: 0000899243-20-026193 · doc4.xml · derivative · entry 5

VV Manager II, LLC · CIK 0001824569 · 10% owner

Vida Ventures II, LLC · CIK 0001776851 · 10% owner

VIDA VENTURES II-A, LLC · CIK 0001781930 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnotes

Disclosed balance after: 0

Underlying: Common Stock · 2,087,130 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: On September 21, 2020, the Series B Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

F1 · derivative.exercise_date: On September 21, 2020, the Series B Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

F1 · derivative.expiration_date: On September 21, 2020, the Series B Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

F2 · ownership.nature: The shares are held directly by Vida Ventures II, LLC ("Vida II"). VV Manager II, LLC ("VV Manager II") is the manager of Vida II. Arie Belldegrun, Fred Cohen, and Leonard Potter are the members of the management committee of VV Manager II (the "Management Committee") and Stefan Vitorovic, Arjun Goyal, Helen Kim, Rajul Jain, and Joshua Kazam are the members of the investment committee of VV Manager II (the "Investment Committee").

F3 · ownership.nature: (Continued from Footnote 2) Each of the Management Committee, the Investment Committee and the respective members thereof may be deemed to share voting and dispositive power over the shares held by Vida II. VV Manager II, the Management Committee, the Investment Committee and each member of each of the Management Committee and Investment Committee disclaims beneficial ownership over the securities held of record by Vida II and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interest therein.

SEC source: 0000899243-20-026193 · doc4.xml · nonDerivative · entry 4

VV Manager II, LLC · CIK 0001824569 · 10% owner

Vida Ventures II, LLC · CIK 0001776851 · 10% owner

VIDA VENTURES II-A, LLC · CIK 0001781930 · 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: 79,921

F4 · ownership.nature: The shares are held directly by Vida Ventures II-A, LLC ("Vida II-A"). VV Manager II is the manager of Vida II-A. Each of the Management Committee ,the Investment Committee and the respective members thereof may be deemed to share voting and dispositive power over the shares held by Vida II-A. VV Manager II, the Management Committee, the Investment Committee and each member of each of the Management Committee and Investment Committee disclaims beneficial ownership over the securities held of record by Vida II-A and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interest therein.

SEC source: 0000899243-20-026193 · doc4.xml · nonDerivative · entry 3

VV Manager II, LLC · CIK 0001824569 · 10% owner

Vida Ventures II, LLC · CIK 0001776851 · 10% owner

VIDA VENTURES II-A, LLC · CIK 0001781930 · 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: 57,916

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: On September 21, 2020, the Series B Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

F4 · ownership.nature: The shares are held directly by Vida Ventures II-A, LLC ("Vida II-A"). VV Manager II is the manager of Vida II-A. Each of the Management Committee ,the Investment Committee and the respective members thereof may be deemed to share voting and dispositive power over the shares held by Vida II-A. VV Manager II, the Management Committee, the Investment Committee and each member of each of the Management Committee and Investment Committee disclaims beneficial ownership over the securities held of record by Vida II-A and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interest therein.

SEC source: 0000899243-20-026193 · doc4.xml · nonDerivative · entry 2

VV Manager II, LLC · CIK 0001824569 · 10% owner

Vida Ventures II, LLC · CIK 0001776851 · 10% owner

VIDA VENTURES II-A, LLC · CIK 0001781930 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnotes

Disclosed balance after: 2,880,125

F2 · ownership.nature: The shares are held directly by Vida Ventures II, LLC ("Vida II"). VV Manager II, LLC ("VV Manager II") is the manager of Vida II. Arie Belldegrun, Fred Cohen, and Leonard Potter are the members of the management committee of VV Manager II (the "Management Committee") and Stefan Vitorovic, Arjun Goyal, Helen Kim, Rajul Jain, and Joshua Kazam are the members of the investment committee of VV Manager II (the "Investment Committee").

F3 · ownership.nature: (Continued from Footnote 2) Each of the Management Committee, the Investment Committee and the respective members thereof may be deemed to share voting and dispositive power over the shares held by Vida II. VV Manager II, the Management Committee, the Investment Committee and each member of each of the Management Committee and Investment Committee disclaims beneficial ownership over the securities held of record by Vida II and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interest therein.

SEC source: 0000899243-20-026193 · doc4.xml · nonDerivative · entry 1

VV Manager II, LLC · CIK 0001824569 · 10% owner

Vida Ventures II, LLC · CIK 0001776851 · 10% owner

VIDA VENTURES II-A, LLC · CIK 0001781930 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnotes

Disclosed balance after: 2,087,130

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: On September 21, 2020, the Series B Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

F2 · ownership.nature: The shares are held directly by Vida Ventures II, LLC ("Vida II"). VV Manager II, LLC ("VV Manager II") is the manager of Vida II. Arie Belldegrun, Fred Cohen, and Leonard Potter are the members of the management committee of VV Manager II (the "Management Committee") and Stefan Vitorovic, Arjun Goyal, Helen Kim, Rajul Jain, and Joshua Kazam are the members of the investment committee of VV Manager II (the "Investment Committee").

F3 · ownership.nature: (Continued from Footnote 2) Each of the Management Committee, the Investment Committee and the respective members thereof may be deemed to share voting and dispositive power over the shares held by Vida II. VV Manager II, the Management Committee, the Investment Committee and each member of each of the Management Committee and Investment Committee disclaims beneficial ownership over the securities held of record by Vida II and this report shall not be deemed an admission that any one of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interest therein.

SEC source: 0000899243-20-026192 · doc4.xml · derivative · entry 5

Lubner David Charles · CIK 0001572000 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 53,625 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: On September 21, 2020, the Series B Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

F1 · derivative.exercise_date: On September 21, 2020, the Series B Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

F1 · derivative.expiration_date: On September 21, 2020, the Series B Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

SEC source: 0000899243-20-026192 · doc4.xml · nonDerivative · entry 1

Lubner David Charles · CIK 0001572000 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 53,625

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: On September 21, 2020, the Series B Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

SEC source: 0000899243-20-026189 · doc4.xml · derivative · entry 3

Logos Global Management LP · CIK 0001792126 · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnotes

Disclosed balance after: 0

Underlying: Common Stock · 804,392 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: On September 21, 2020, the Series B Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

F1 · derivative.exercise_date: On September 21, 2020, the Series B Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

F1 · derivative.expiration_date: On September 21, 2020, the Series B Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

F2 · ownership.nature: The reporting persons are Logos Opportunities Fund II LP (the "Fund"), Logos Global Management LP ("LGM"), Logos Global Management GP LLC ("LGM GP"), Logos Opportunities GP LLC ("Fund GP"), Logos GP LLC ("Logos GP"), Dr. Arsani William and Dr. Graham Walmsley. LGM is the investment adviser of private funds, including the Fund. LGM GP is the general partner of LGM. Fund GP is the general partner of the Fund. Logos GP is the manager of Fund GP. Dr. William and Dr. Walmsley are controlling persons of LGM and Logos GP and managers of the Fund. LGM is filing this report for itself and the other reporting persons. The reporting persons are filing this Form 3 jointly, but not as a group, and each expressly disclaims membership in a group within the meaning of Rule 13d-5(b) under the Securities Exchange Act of 1934.

F3 · ownership.nature: The Fund holds the securities reported herein directly for the benefit of its investors. The securities may be deemed to be indirectly beneficially owned by LGM as investment adviser to the Fund, by LGM GP as general partner of LGM, by Fund GP as general partner of the Fund, by Logos GP as manager of Fund GP and by Dr. William and Dr. Walmsley as controlling persons of LGM and Logos GP. The reporting persons disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein.

SEC source: 0000899243-20-026189 · doc4.xml · nonDerivative · entry 2

Logos Global Management LP · CIK 0001792126 · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnotes

Disclosed balance after: 1,504,392

F2 · ownership.nature: The reporting persons are Logos Opportunities Fund II LP (the "Fund"), Logos Global Management LP ("LGM"), Logos Global Management GP LLC ("LGM GP"), Logos Opportunities GP LLC ("Fund GP"), Logos GP LLC ("Logos GP"), Dr. Arsani William and Dr. Graham Walmsley. LGM is the investment adviser of private funds, including the Fund. LGM GP is the general partner of LGM. Fund GP is the general partner of the Fund. Logos GP is the manager of Fund GP. Dr. William and Dr. Walmsley are controlling persons of LGM and Logos GP and managers of the Fund. LGM is filing this report for itself and the other reporting persons. The reporting persons are filing this Form 3 jointly, but not as a group, and each expressly disclaims membership in a group within the meaning of Rule 13d-5(b) under the Securities Exchange Act of 1934.

F3 · ownership.nature: The Fund holds the securities reported herein directly for the benefit of its investors. The securities may be deemed to be indirectly beneficially owned by LGM as investment adviser to the Fund, by LGM GP as general partner of LGM, by Fund GP as general partner of the Fund, by Logos GP as manager of Fund GP and by Dr. William and Dr. Walmsley as controlling persons of LGM and Logos GP. The reporting persons disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein.

SEC source: 0000899243-20-026189 · doc4.xml · nonDerivative · entry 1

Logos Global Management LP · CIK 0001792126 · 10% owner

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnotes

Disclosed balance after: 804,392

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: On September 21, 2020, the Series B Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

F2 · ownership.nature: The reporting persons are Logos Opportunities Fund II LP (the "Fund"), Logos Global Management LP ("LGM"), Logos Global Management GP LLC ("LGM GP"), Logos Opportunities GP LLC ("Fund GP"), Logos GP LLC ("Logos GP"), Dr. Arsani William and Dr. Graham Walmsley. LGM is the investment adviser of private funds, including the Fund. LGM GP is the general partner of LGM. Fund GP is the general partner of the Fund. Logos GP is the manager of Fund GP. Dr. William and Dr. Walmsley are controlling persons of LGM and Logos GP and managers of the Fund. LGM is filing this report for itself and the other reporting persons. The reporting persons are filing this Form 3 jointly, but not as a group, and each expressly disclaims membership in a group within the meaning of Rule 13d-5(b) under the Securities Exchange Act of 1934.

F3 · ownership.nature: The Fund holds the securities reported herein directly for the benefit of its investors. The securities may be deemed to be indirectly beneficially owned by LGM as investment adviser to the Fund, by LGM GP as general partner of LGM, by Fund GP as general partner of the Fund, by Logos GP as manager of Fund GP and by Dr. William and Dr. Walmsley as controlling persons of LGM and Logos GP. The reporting persons disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein.

SEC source: 0000899243-20-026186 · doc4.xml · derivative · entry 3

Forbion Capital Fund IV Cooperatief U.A. · CIK 0001823747 · 10% owner

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 1,608,786 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: On September 21, 2020, the Series B Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

F2 · derivative.exercise_date: On September 21, 2020, the Series B Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

F2 · derivative.expiration_date: On September 21, 2020, the Series B Preferred Stock automatically converted into Common Stock on a 3.3169-for-one basis without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.

F3 · ownership.direct: The shares are held directly by Forbion Capital Fund IV Cooperatief U.A ("FCF IV"). Forbion IV Management B.V. ("Forbion Management") the director of FCF IV, may be deemed to have voting and dispositive power over the shares held by FCF IV. Investment decisions with respect to the shares held by FCF IV can be made by FCPM III Services B.V., the director of Forbion Management, which may delegate such powers to its investment committee which may delegate such powers to the authorized representatives of Forbion Management. Messrs. Slootweg, van Osch, Mulder, van Houten, Reithinger and Boorsma (the "Partners") are partners of FCPM III Services B.V., which acts as the investment advisor to the directors of FCF IV. Each of the Partners disclaims beneficial ownership of such shares, except to the extent of his pecuniary interest therein.