SYBX

SEC source: 0000950170-23-063925 · ownership.xml · derivative · entry 5

Awad Antoine · CIK 0001820122 · Chief Operating Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 4,666 shares

Expires 2030-07-14

F1 · derivative.exercise_price: In accordance with the terms of the Synlogic, Inc. 2015 Equity Incentive Award Plan and the Company's 2017 Stock Incentive Plan (together the "Plans"), the Board of Directors of Synlogic, Inc. approved a stock option repricing pursuant to which option awards granted under the Plans were amended to reduce the exercise price to $1.85 per share, the closing stock price of the Company's Common Stock on November 10, 2023. Except for the modified exercise price, all other terms and conditions of each of the option awards will continue as set forth in the Plan and the applicable award agreements.

F1 · price: In accordance with the terms of the Synlogic, Inc. 2015 Equity Incentive Award Plan and the Company's 2017 Stock Incentive Plan (together the "Plans"), the Board of Directors of Synlogic, Inc. approved a stock option repricing pursuant to which option awards granted under the Plans were amended to reduce the exercise price to $1.85 per share, the closing stock price of the Company's Common Stock on November 10, 2023. Except for the modified exercise price, all other terms and conditions of each of the option awards will continue as set forth in the Plan and the applicable award agreements.

F5 · derivative.exercise_date: The shares subject to this option vest in approximately equal monthly installments beginning on July 1, 2020 through July 1, 2024.

SEC source: 0000950170-23-063925 · ownership.xml · derivative · entry 4

Awad Antoine · CIK 0001820122 · Chief Operating Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 4,666 shares

Expires 2030-03-10

F1 · derivative.exercise_price: In accordance with the terms of the Synlogic, Inc. 2015 Equity Incentive Award Plan and the Company's 2017 Stock Incentive Plan (together the "Plans"), the Board of Directors of Synlogic, Inc. approved a stock option repricing pursuant to which option awards granted under the Plans were amended to reduce the exercise price to $1.85 per share, the closing stock price of the Company's Common Stock on November 10, 2023. Except for the modified exercise price, all other terms and conditions of each of the option awards will continue as set forth in the Plan and the applicable award agreements.

F1 · price: In accordance with the terms of the Synlogic, Inc. 2015 Equity Incentive Award Plan and the Company's 2017 Stock Incentive Plan (together the "Plans"), the Board of Directors of Synlogic, Inc. approved a stock option repricing pursuant to which option awards granted under the Plans were amended to reduce the exercise price to $1.85 per share, the closing stock price of the Company's Common Stock on November 10, 2023. Except for the modified exercise price, all other terms and conditions of each of the option awards will continue as set forth in the Plan and the applicable award agreements.

F4 · derivative.exercise_date: The shares subject to this option vest in approximately equal monthly installments beginning on April 1, 2020 through April 1, 2024.

SEC source: 0000950170-23-063925 · ownership.xml · derivative · entry 3

Awad Antoine · CIK 0001820122 · Chief Operating Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 6,666 shares

Expires 2033-03-16

F1 · derivative.exercise_price: In accordance with the terms of the Synlogic, Inc. 2015 Equity Incentive Award Plan and the Company's 2017 Stock Incentive Plan (together the "Plans"), the Board of Directors of Synlogic, Inc. approved a stock option repricing pursuant to which option awards granted under the Plans were amended to reduce the exercise price to $1.85 per share, the closing stock price of the Company's Common Stock on November 10, 2023. Except for the modified exercise price, all other terms and conditions of each of the option awards will continue as set forth in the Plan and the applicable award agreements.

F1 · price: In accordance with the terms of the Synlogic, Inc. 2015 Equity Incentive Award Plan and the Company's 2017 Stock Incentive Plan (together the "Plans"), the Board of Directors of Synlogic, Inc. approved a stock option repricing pursuant to which option awards granted under the Plans were amended to reduce the exercise price to $1.85 per share, the closing stock price of the Company's Common Stock on November 10, 2023. Except for the modified exercise price, all other terms and conditions of each of the option awards will continue as set forth in the Plan and the applicable award agreements.

F3 · derivative.exercise_date: These performance-based stock options, granted on March 16, 2023, vest when the achievement of certain clinical and regulatory development milestones are met.

SEC source: 0000950170-23-063925 · ownership.xml · derivative · entry 2

Awad Antoine · CIK 0001820122 · Chief Operating Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 666 shares

Expires 2029-03-05

F1 · derivative.exercise_price: In accordance with the terms of the Synlogic, Inc. 2015 Equity Incentive Award Plan and the Company's 2017 Stock Incentive Plan (together the "Plans"), the Board of Directors of Synlogic, Inc. approved a stock option repricing pursuant to which option awards granted under the Plans were amended to reduce the exercise price to $1.85 per share, the closing stock price of the Company's Common Stock on November 10, 2023. Except for the modified exercise price, all other terms and conditions of each of the option awards will continue as set forth in the Plan and the applicable award agreements.

F1 · price: In accordance with the terms of the Synlogic, Inc. 2015 Equity Incentive Award Plan and the Company's 2017 Stock Incentive Plan (together the "Plans"), the Board of Directors of Synlogic, Inc. approved a stock option repricing pursuant to which option awards granted under the Plans were amended to reduce the exercise price to $1.85 per share, the closing stock price of the Company's Common Stock on November 10, 2023. Except for the modified exercise price, all other terms and conditions of each of the option awards will continue as set forth in the Plan and the applicable award agreements.

F2 · derivative.exercise_date: The shares subject to this option are fully vested as of the date hereof.

SEC source: 0000950170-23-063925 · ownership.xml · derivative · entry 1

Awad Antoine · CIK 0001820122 · Chief Operating Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 3,666 shares

Expires 2029-02-28

F1 · derivative.exercise_price: In accordance with the terms of the Synlogic, Inc. 2015 Equity Incentive Award Plan and the Company's 2017 Stock Incentive Plan (together the "Plans"), the Board of Directors of Synlogic, Inc. approved a stock option repricing pursuant to which option awards granted under the Plans were amended to reduce the exercise price to $1.85 per share, the closing stock price of the Company's Common Stock on November 10, 2023. Except for the modified exercise price, all other terms and conditions of each of the option awards will continue as set forth in the Plan and the applicable award agreements.

F1 · price: In accordance with the terms of the Synlogic, Inc. 2015 Equity Incentive Award Plan and the Company's 2017 Stock Incentive Plan (together the "Plans"), the Board of Directors of Synlogic, Inc. approved a stock option repricing pursuant to which option awards granted under the Plans were amended to reduce the exercise price to $1.85 per share, the closing stock price of the Company's Common Stock on November 10, 2023. Except for the modified exercise price, all other terms and conditions of each of the option awards will continue as set forth in the Plan and the applicable award agreements.

F2 · derivative.exercise_date: The shares subject to this option are fully vested as of the date hereof.

SEC source: 0000950170-23-029805 · ownership.xml · derivative · entry 1

Burgess Michael F. · CIK 0001801745 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 30,000

Underlying: Common Stock · 30,000 shares

Expires 2033-06-22

F1 · derivative.exercise_date: The option vests and becomes exercisable in full on the earlier of (A) the first anniversary of the date of grant or (B) immediately prior to the next annual meeting of the Corporation's stockholders after the date of grant, subject to the non-employee director's continued service as a director of the Corporation.

SEC source: 0000950170-23-029802 · ownership.xml · derivative · entry 1

Heffernan Michael Thomas · CIK 0001448914 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 30,000

Underlying: Common Stock · 30,000 shares

Expires 2033-06-22

F1 · derivative.exercise_date: The option vests and becomes exercisable in full on the earlier of (A) the first anniversary of the date of grant or (B) immediately prior to the next annual meeting of the Corporation's stockholders after the date of grant, subject to the non-employee director's continued service as a director of the Corporation.

SEC source: 0000950170-23-029787 · ownership.xml · derivative · entry 1

Barrett Peter · CIK 0001291895 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 30,000

Underlying: Common Stock · 30,000 shares

Expires 2033-06-22

F1 · derivative.exercise_date: The option vests and becomes exercisable in full on the earlier of (A) the first anniversary of the date of grant or (B) immediately prior to the next annual meeting of the Corporation's stockholders after the date of grant, subject to the non-employee director's continued service as a director of the Corporation.

F2 · ownership.direct: The reporting person is a member of Atlas Venture Associates IX, LLC ("AVA IX LLC") and is obligated to transfer the economic benefit, if any, received upon the sale of the shares issuable upon exercise of the equity grants to Atlas Venture Advisors, L.P. 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: 0000950170-23-029809 · ownership.xml · derivative · entry 1

Shea Richard P · CIK 0001294354 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 30,000

Underlying: Common Stock · 30,000 shares

Expires 2033-06-22

F1 · derivative.exercise_date: The option vests and becomes exercisable in full on the earlier of (A) the first anniversary of the date of grant or (B) immediately prior to the next annual meeting of the Corporation's stockholders after the date of grant, subject to the non-employee director's continued service as a director of the Corporation.

SEC source: 0001209191-23-039666 · doc4.xml · derivative · entry 1

Mathers Edward T · CIK 0001328625 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 30,000

Underlying: Common Stock · 30,000 shares

Expires 2033-06-22

F1 · derivative.exercise_date: The option vests and becomes exercisable in full on the earlier of (A) the first anniversary of the date of grant or (B) immediately prior to the next annual meeting of the Corporation's stockholders after the date of grant, subject to the non-employee director's continued service as a director of the Corporation.

SEC source: 0000950170-23-029808 · ownership.xml · derivative · entry 1

Leschly Nick · CIK 0001578408 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 30,000

Underlying: Common Stock · 30,000 shares

Expires 2033-06-22

F1 · derivative.exercise_date: The option vests and becomes exercisable in full on the earlier of (A) the first anniversary of the date of grant or (B) immediately prior to the next annual meeting of the Corporation's stockholders after the date of grant, subject to the non-employee director's continued service as a director of the Corporation.

SEC source: 0000950170-23-029804 · ownership.xml · derivative · entry 1

Kelly-Croswell Lisa · CIK 0001845596 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 30,000

Underlying: Common Stock · 30,000 shares

Expires 2033-06-22

F1 · derivative.exercise_date: The option vests and becomes exercisable in full on the earlier of (A) the first anniversary of the date of grant or (B) immediately prior to the next annual meeting of the Corporation's stockholders after the date of grant, subject to the non-employee director's continued service as a director of the Corporation.

SEC source: 0000950170-23-029797 · ownership.xml · derivative · entry 1

Hurter Patricia N. · CIK 0001767191 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 30,000

Underlying: Common Stock · 30,000 shares

Expires 2033-06-22

F1 · derivative.exercise_date: The option vests and becomes exercisable in full on the earlier of (A) the first anniversary of the date of grant or (B) immediately prior to the next annual meeting of the Corporation's stockholders after the date of grant, subject to the non-employee director's continued service as a director of the Corporation.

SEC source: 0000899243-23-010715 · doc4.xml · nonDerivative · entry 1

Brennan Aoife · CIK 0001714563 · Director · See Remarks

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 256,301

F1 · shares: Represents the number of shares sold by the reporting person on April 3, 2023 to cover the tax liability in connection with the vesting of three restricted stock awards, vesting on April 1, 2023, that were granted in 2020, 2021, and 2022. The transaction reported on this Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on May 16, 2022.

F2 · price: The price reported is a weighted average price. These shares were sold in multiple transactions at prices ranging from $0.5750 to $0.5798, inclusive. The reporting person will provide to the staff of the Securities and Exchange Commission, the issuer, or any security holder of the issuer, upon request, full information regarding the number of shares sold at each separate price.

SEC source: 0000899243-23-010716 · doc4.xml · nonDerivative · entry 1

Awad Antoine · CIK 0001820122 · Chief Operating Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 74,732

F1 · shares: Represents the number of shares sold by the reporting person on April 3, 2023 to cover the tax liability in connection with the vesting of three restricted stock awards, vesting on April 1, 2023, that were granted in 2020, 2021, and 2022.

F2 · price: The price reported is a weighted average price. These shares were sold in multiple transactions at prices ranging from $0.5750 to $0.5798, inclusive. The reporting person will provide to the staff of the Securities and Exchange Commission, the issuer, or any security holder of the issuer, upon request, full information regarding the number of shares sold at each separate price.

SEC source: 0000899243-23-010714 · doc4.xml · nonDerivative · entry 1

JENSEN MICHAEL VANGSTED · CIK 0001914184 · Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 46,947

F1 · shares: Represents the number of shares sold by the reporting person on April 3, 2023 to cover the tax liability in connection with the vesting of a restricted stock award, vesting on April 1, 2023, that was granted in 2022.

F2 · price: The price reported is a weighted average price. These shares were sold in multiple transactions at prices ranging from $0.5750 to $0.5798, inclusive. The reporting person will provide to the staff of the Securities and Exchange Commission, the issuer, or any security holder of the issuer, upon request, full information regarding the number of shares sold at each separate price.

F3 · balance_after: Includes 5,000 shares acquired on September 30, 2022 and 5,000 shares acquired on March 31, 2023 under the Synlogic, Inc. 2015 Employee Stock Purchase Plan.

SEC source: 0000899243-23-000663 · doc4.xml · derivative · entry 1

Barrett Peter · CIK 0001291895 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 156,130

Underlying: Common Stock · 156,130 shares

Expires 2033-01-03

F1 · derivative.exercise_date: The options were issued to the Reporting Person pursuant to the Issuer's Amended and Restated Non-Employee Director Compensation Program and 2015 Equity Incentive Award Plan in lieu of the non-employee director board and committee cash retainers of $81,500 in the aggregate. Such options vest in four equal quarterly installments on the last day of each calendar quarter during 2023 provided the Reporting Person continues to provide services to the Issuer.

F2 · ownership.direct: The reporting person is a member of Atlas Venture Associates IX, LLC and is obligated to transfer the economic benefit, if any, received upon the sale of the shares issuable upon exercise of the equity grants to Atlas Venture Advisors, L.P. 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: 0000899243-23-000662 · doc4.xml · derivative · entry 1

Hurter Patricia N. · CIK 0001767191 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 91,954

Underlying: Common Stock · 91,954 shares

Expires 2033-01-03

F1 · derivative.exercise_date: The options were issued to the Reporting Person pursuant to the Issuer's Amended and Restated Non-Employee Director Compensation Program and 2015 Equity Incentive Award Plan in lieu of the non-employee director board and committee cash retainers of $48,000 in the aggregate. Such options vest in four equal quarterly installments on the last day of each calendar quarter during 2023 provided the Reporting Person continues to provide services to the Issuer.

SEC source: 0000899243-22-022176 · doc4.xml · derivative · entry 1

Burgess Michael F. · CIK 0001801745 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 27,000

Underlying: Common Stock · 27,000 shares

Expires 2032-06-09

F1 · derivative.exercise_date: The option vests and becomes exercisable in full on the earlier of (A) the first anniversary of the date of grant or (B) immediately prior to the next annual meeting of the Corporation's stockholders after the date of grant, subject to the non-employee director's continued service as a director of the Corporation.

SEC source: 0000899243-22-022178 · doc4.xml · derivative · entry 1

Heffernan Michael Thomas · CIK 0001448914 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 27,000

Underlying: Common Stock · 27,000 shares

Expires 2032-06-09

F1 · derivative.exercise_date: The option vests and becomes exercisable in full on the earlier of (A) the first anniversary of the date of grant or (B) immediately prior to the next annual meeting of the Corporation's stockholders after the date of grant, subject to the non-employee director's continued service as a director of the Corporation.

SEC source: 0000899243-22-022177 · doc4.xml · derivative · entry 1

Shea Richard P · CIK 0001294354 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 27,000

Underlying: Common Stock · 27,000 shares

Expires 2032-06-09

F1 · derivative.exercise_date: The option vests and becomes exercisable in full on the earlier of (A) the first anniversary of the date of grant or (B) immediately prior to the next annual meeting of the Corporation's stockholders after the date of grant, subject to the non-employee director's continued service as a director of the Corporation.

SEC source: 0000899243-22-022180 · doc4.xml · derivative · entry 1

Barrett Peter · CIK 0001291895 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 27,000

Underlying: Common Stock · 27,000 shares

Expires 2032-06-09

F1 · derivative.exercise_date: The option vests and becomes exercisable in full on the earlier of (A) the first anniversary of the date of grant or (B) immediately prior to the next annual meeting of the Corporation's stockholders after the date of grant, subject to the non-employee director's continued service as a director of the Corporation.

F2 · ownership.direct: The reporting person is a member of Atlas Venture Associates IX, LLC ("AVA IX LLC") and is obligated to transfer the economic benefit, if any, received upon the sale of the shares issuable upon exercise of the equity grants to Atlas Venture Advisors, L.P. 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: 0001209191-22-036358 · doc4.xml · derivative · entry 1

Mathers Edward T · CIK 0001328625 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 27,000

Underlying: Common Stock · 27,000 shares

Expires 2032-06-09

F1 · derivative.exercise_date: The option vests and becomes exercisable in full on the earlier of (A) the first anniversary of the date of grant or (B) immediately prior to the next annual meeting of the Corporation's stockholders after the date of grant, subject to the non-employee-director's continued service as a director of the Corporation.

SEC source: 0000899243-22-022181 · doc4.xml · derivative · entry 1

Leschly Nick · CIK 0001578408 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 27,000

Underlying: Common Stock · 27,000 shares

Expires 2032-06-09

F1 · derivative.exercise_date: The option vests and becomes exercisable in full on the earlier of (A) the first anniversary of the date of grant or (B) immediately prior to the next annual meeting of the Corporation's stockholders after the date of grant, subject to the non-employee director's continued service as a director of the Corporation.

SEC source: 0000899243-22-022175 · doc4.xml · derivative · entry 1

Kelly-Croswell Lisa · CIK 0001845596 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 27,000

Underlying: Common Stock · 27,000 shares

Expires 2032-06-09

F1 · derivative.exercise_date: The option vests and becomes exercisable in full on the earlier of (A) the first anniversary of the date of grant or (B) immediately prior to the next annual meeting of the Corporation's stockholders after the date of grant, subject to the non-employee director's continued service as a director of the Corporation.

SEC source: 0000899243-22-022179 · doc4.xml · derivative · entry 1

Hurter Patricia N. · CIK 0001767191 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 27,000

Underlying: Common Stock · 27,000 shares

Expires 2032-06-09

F1 · derivative.exercise_date: The option vests and becomes exercisable in full on the earlier of (A) the first anniversary of the date of grant or (B) immediately prior to the next annual meeting of the Corporation's stockholders after the date of grant, subject to the non-employee director's continued service as a director of the Corporation.

SEC source: 0000899243-22-019461 · doc4.xml · nonDerivative · entry 1

JENSEN MICHAEL VANGSTED · CIK 0001914184 · Chief Financial Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 39,500

SEC source: 0000899243-22-014110 · doc4.xml · nonDerivative · entry 1

Brennan Aoife · CIK 0001714563 · Director · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 275,343

F1 · shares: Represents the number of shares sold by the reporting person on April 4, 2022 to cover the tax liability in connection with the vesting of two restricted stock awards, vesting on April 1, 2022, that were granted in 2020 and 2021. The transaction reported on this Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 26, 2021.

F2 · price: The price reported is a weighted average price. These shares were sold in multiple transactions at prices ranging from $2.40 to $2.45, inclusive. The reporting person will provide to the staff of the Securities and Exchange Commission, the issuer, or any security holder of the issuer, upon request, full information regarding the number of shares sold at each separate price.

SEC source: 0000899243-22-014109 · doc4.xml · nonDerivative · entry 1

Awad Antoine · CIK 0001820122 · Chief Operating Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 81,170

F1 · shares: Represents the number of shares sold by the reporting person on April 4, 2022 to cover the tax liability in connection with the vesting of two restricted stock awards, vesting on April 1, 2022, that were granted in 2020 and 2021. The transaction reported on this Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 23, 2021.

F2 · price: The price reported is a weighted average price. These shares were sold in multiple transactions at prices ranging from $2.40 to $2.45, inclusive. The reporting person will provide to the staff of the Securities and Exchange Commission, the issuer, or any security holder of the issuer, upon request, full information regarding the number of shares sold at each separate price.

SEC source: 0000899243-22-009122 · doc4.xml · derivative · entry 2

JENSEN MICHAEL VANGSTED · CIK 0001914184 · Chief Financial Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 230,000

Underlying: Common Stock · 230,000 shares

Expires 2032-03-03

F2 · derivative.exercise_date: The options were granted on March 3, 2022, and will vest 25% on the first anniversary of the date of grant and the remaining options will vest in thirty-six equal monthly installments thereafter, subject to the Reporting Person continuing to provide services to the Issuer as Chief Financial Officer through each such vesting date.

SEC source: 0000899243-22-009122 · doc4.xml · nonDerivative · entry 1

JENSEN MICHAEL VANGSTED · CIK 0001914184 · Chief Financial Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 30,000

F1 · shares: The shares of restricted stock were granted on March 3, 2022, and will vest in four equal annual installments on each of the first four anniversaries of April 1, 2022, subject to the Reporting Person continuing to provide services to the Issuer as Chief Financial Officer through each such vesting date.

SEC source: 0000899243-22-005213 · doc4.xml · derivative · entry 2

Brennan Aoife · CIK 0001714563 · Director · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 434,160

Underlying: Common Stock · 434,160 shares

Expires 2032-02-04

F2 · derivative.exercise_date: The option will vest and become exercisable in equal monthly installments for forty-eight months beginning on the grant date, which is February 4, 2022, subject to the Reporting Person continuing to provide services to the Issuer as Chief Executive Officer through each such vesting date.

SEC source: 0000899243-22-005213 · doc4.xml · nonDerivative · entry 1

Brennan Aoife · CIK 0001714563 · Director · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 284,237

F1 · shares: The shares of restricted stock were granted on February 4, 2022, and will vest beginning on April 1, 2022 (the "Vesting Start Date") in four equal annual installments on each anniversary of the Vesting Start Date, subject to the Reporting Person continuing to provide services to the Issuer as Chief Executive Officer through each such vesting date.

SEC source: 0000899243-22-005207 · doc4.xml · derivative · entry 2

Awad Antoine · CIK 0001820122 · Chief Operating Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 165,490

Underlying: Common Stock · 165,490 shares

Expires 2032-02-04

F2 · derivative.exercise_date: The option will vest and become exercisable in equal monthly installments for forty-eight months beginning on the date of the grant, which is February 4, 2022, subject to the Reporting Person continuing to provide services to the Issuer as Chief Operating Officer through each such vesting date.

SEC source: 0000899243-22-005207 · doc4.xml · nonDerivative · entry 1

Awad Antoine · CIK 0001820122 · Chief Operating Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 83,820

F1 · shares: The shares of restricted stock were granted on February 4, 2022, and will vest beginning on April 1, 2022 (the "Vesting Start Date") in four equal annual installments on each anniversary of the Vesting Start Date, subject to the Reporting Person continuing to provide services to the Issuer as Chief Operating Officer through each such vesting date.

SEC source: 0000899243-22-000897 · doc4.xml · derivative · entry 1

Barrett Peter · CIK 0001291895 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 49,334

Underlying: Common Stock · 49,334 shares

Expires 2032-01-03

F1 · derivative.exercise_date: The options were issued to the Reporting Person pursuant to the Issuer's Amended and Restated Non-Employee Director Compensation Program and 2015 Equity Incentive Award Plan in lieu of the non-employee director board and committee cash retainers of $81,500 in the aggregate. Such options vest in four equal quarterly installments on the last day of each calendar quarter during 2022 provided the Reporting Person continues to provide services to the Issuer.

F2 · ownership.direct: The reporting person is a member of Atlas Venture Associates IX, LLC ("AVA IX LLC") and is obligated to transfer the economic benefit, if any, received upon the sale of the shares issuable upon exercise of the equity grants to Atlas Venture Advisors, L.P. 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: 0000899243-22-003838 · doc4.xml · derivative · entry 1

BELOFF GREGG · CIK 0001171002 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 50,000

Underlying: Common Stock · 50,000 shares

Expires 2031-12-06

F1 · derivative.exercise_date: The options were issued to the Reporting Person pursuant to the Issuer's 2015 Equity Incentive Award Plan. Such options vest in 12 equal monthly installments starting November 1, 2021, provided the Reporting Person continues to provide services to the Issuer. An aggregate of 50% of the options shall vest immediately if the Issuer terminates the Reporting Person's services before May 1, 2022.

SEC source: 0000899243-21-023616 · doc4.xml · derivative · entry 1

Burgess Michael F. · CIK 0001801745 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 15,000

Underlying: Common Stock · 15,000 shares

Expires 2031-06-10

F1 · derivative.exercise_date: The option vests and becomes exercisable in full on the earlier of (A) the first anniversary of the date of grant or (B) immediately prior to the next annual meeting of the Corporation's stockholders after the date of grant, subject to the non-employee director's continued service as a director of the Corporation.

SEC source: 0000899243-21-023605 · doc4.xml · derivative · entry 1

Heffernan Michael Thomas · CIK 0001448914 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 15,000

Underlying: Common Stock · 15,000 shares

Expires 2031-06-10

F1 · derivative.exercise_date: The option vests and becomes exercisable in full on the earlier of (A) the first anniversary of the date of grant or (B) immediately prior to the next annual meeting of the Corporation's stockholders after the date of grant, subject to the non-employee director's continued service as a director of the Corporation.

SEC source: 0000899243-21-023617 · doc4.xml · derivative · entry 1

Shea Richard P · CIK 0001294354 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 15,000

Underlying: Common Stock · 15,000 shares

Expires 2031-06-10

F1 · derivative.exercise_date: The option vests and becomes exercisable in full on the earlier of (A) the first anniversary of the date of grant or (B) immediately prior to the next annual meeting of the Corporation's stockholders after the date of grant, subject to the non-employee director's continued service as a director of the Corporation.

SEC source: 0000899243-21-023604 · doc4.xml · derivative · entry 1

Barrett Peter · CIK 0001291895 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 12,818

Underlying: Common Stock · 12,818 shares

Expires 2031-06-10

F1 · derivative.exercise_date: The option vests and becomes exercisable in full on the earlier of (A) the first anniversary of the date of grant or (B) immediately prior to the next annual meeting of the Corporation's stockholders after the date of grant, subject to the non-employee director's continued service as a director of the Corporation.

F2 · ownership.direct: The reporting person is a member of Atlas Venture Associates IX, LLC ("AVA IX LLC") and is obligated to transfer the economic benefit, if any, received upon the sale of the shares issuable upon exercise of the equity grants to Atlas Venture Advisors, L.P. 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: 0001209191-21-040335 · doc4.xml · derivative · entry 1

Mathers Edward T · CIK 0001328625 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 15,000

Underlying: Common Stock · 15,000 shares

Expires 2031-06-10

F1 · derivative.exercise_date: The option vests and becomes exercisable in full on the earlier of (A) the first anniversary of the date of grant or (B) immediately prior to the next annual meeting of the Corporation's stockholders after the date of grant, subject to the non-employee director's continued service as a director of the Corporation.

SEC source: 0000899243-21-023614 · doc4.xml · derivative · entry 1

Leschly Nick · CIK 0001578408 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 15,000

Underlying: Common Stock · 15,000 shares

Expires 2031-06-10

F1 · derivative.exercise_date: The option vests and becomes exercisable in full on the earlier of (A) the first anniversary of the date of grant or (B) immediately prior to the next annual meeting of the Corporation's stockholders after the date of grant, subject to the non-employee director's continued service as a director of the Corporation.

SEC source: 0000899243-21-023606 · doc4.xml · derivative · entry 1

Hurter Patricia N. · CIK 0001767191 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 15,000

Underlying: Common Stock · 15,000 shares

Expires 2031-06-10

F1 · derivative.exercise_date: The option vests and becomes exercisable in full on the earlier of (A) the first anniversary of the date of grant or (B) immediately prior to the next annual meeting of the Corporation's stockholders after the date of grant, subject to the non-employee director's continued service as a director of the Corporation.

SEC source: 0000899243-21-023609 · doc4.xml · derivative · entry 1

Kelly-Croswell Lisa · CIK 0001845596 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 15,000

Underlying: Common Stock · 15,000 shares

Expires 2031-06-10

F1 · derivative.exercise_date: The option vests and becomes exercisable in full on the earlier of (A) the first anniversary of the date of grant or (B) immediately prior to the next annual meeting of the Corporation's stockholders after the date of grant, subject to the non-employee director's continued service as a director of the Corporation.

SEC source: 0000947871-21-000455 · ownership.xml · nonDerivative · entry 1

ORBIMED ADVISORS LLC · CIK 0001055951 · Director

OrbiMed Capital GP VI LLC · CIK 0001682115 · Director

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 3,696,662

F1 · price: These shares of the Issuer's common stock were sold in an underwritten public offering at a price of $3.00 per share.

F2 · ownership.nature: These shares of the Issuer's common stock are held of record by OrbiMed Private Investments VI, LP ("OPI VI"). OrbiMed Capital GP VI LLC ("GP VI") is the general partner of OPI VI, and OrbiMed Advisors LLC ("OrbiMed Advisors"), a registered investment adviser under the Investment Advisors Act of 1940, as amended, is the managing member of GP VI. By virtue of such relationships, GP VI and OrbiMed Advisors may be deemed to have voting and investment power with respect to the securities held by OPI VI noted above and as a result may be deemed to beneficially own such securities for purposes of Rule 13d-3 under the Securities Exchange Act of 1934, as amended (the "Exchange Act"). OrbiMed Advisors exercises this investment and voting power through a management committee comprised of Carl L. Gordon, Sven H. Borho, and Jonathan T. Silverstein, each of whom disclaims beneficial ownership of the Shares held by OPI VI.

F3 · ownership.nature: This report on Form 4 is jointly filed by GP VI and OrbiMed Advisors. Each of the Reporting Persons disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Exchange Act, except to the extent of its pecuniary interest therein, if any. The Reporting Persons have designated a representative, currently Chau Khuong ("Khuong"), an employee of OrbiMed Advisors, to serve on the Issuer's board of directors. This report shall not be deemed an admission that any of the Reporting Persons or Khuong is a beneficial owner of such securities for the purposes of Section 16 of the Exchange Act, or for any other purposes.

SEC source: 0000947871-21-000454 · ownership.xml · nonDerivative · entry 1

Khuong Chau Quang · CIK 0001609405 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 3,696,662

F1 · price: These shares of the Issuer's common stock were sold in an underwritten public offering at a price of $3.00 per share.

F2 · ownership.nature: These shares of the Issuer's common stock are held of record by OrbiMed Private Investments VI, LP ("OPI VI"). OrbiMed Capital GP VI LLC ("GP V") is the general partner of OPI VI, and OrbiMed Advisors LLC ("OrbiMed Advisors"), a registered investment adviser under the Investment Advisors Act of 1940, as amended, is the managing member of GP VI. The Reporting Person is an employee of OrbiMed Advisors. By virtue of such relationships, GP VI and OrbiMed Advisors may be deemed to have voting and investment power with respect to the securities held by OPI VI noted above and as a result may be deemed to beneficially own such securities for purposes of Rule 13d-3 under the Securities Exchange Act of 1934, as amended (the "Exchange Act"). OrbiMed Advisors exercises this investment and voting power through a management committee comprised of Carl L. Gordon, Sven H. Borho, and Jonathan T. Silverstein, each of whom disclaims beneficial ownership of the Shares held by OPI VI.

F3 · ownership.nature: Each of the Reporting Person, GP VI, and OrbiMed Advisors disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Exchange Act, except to the extent of his or its pecuniary interest therein, if any. This report shall not be deemed an admission that any of the Reporting Person, GP VI or OrbiMed Advisors is a beneficial owner of such securities for the purposes of Section 16 of the Exchange Act, or for any other purposes.

SEC source: 0000899243-21-011336 · doc4.xml · derivative · entry 2

Riese Richard J. · CIK 0001786692 · Chief Medical Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 70,000

Underlying: Common Stock · 70,000 shares

Expires 2031-03-10

F2 · derivative.exercise_date: The option will vest and become exercisable in equal monthly installments for forty-eight months beginning on April 1, 2021, with the first installment vesting on May 1, 2021 subject to the Reporting Person continuing to provide services to the Issuer as Chief Medical Officer through each such vesting date.

SEC source: 0000899243-21-011336 · doc4.xml · nonDerivative · entry 1

Riese Richard J. · CIK 0001786692 · Chief Medical Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 39,000

F1 · shares: The shares of restricted stock were granted on March 10, 2021, and will vest beginning on April 1, 2021 (the "Vesting Start Date") in four equal annual installments on each anniversary of the Vesting Start Date, subject to the Reporting Person continuing to provide services to the Issuer as Chief Medical Officer through each such vesting date.

SEC source: 0000899243-21-011334 · doc4.xml · derivative · entry 2

Brennan Aoife · CIK 0001714563 · Director · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 285,000

Underlying: Common Stock · 285,000 shares

Expires 2031-03-10

F2 · derivative.exercise_date: The option will vest and become exercisable in equal monthly installments for forty-eight months beginning on April 1, 2021, with the first installment vesting on May 1, 2021, subject to the Reporting Person continuing to provide services to the Issuer as Chief Executive Officer through each such vesting date.