Booth Bruce

SEC source: 0001451612-25-000008 · form4-10152025_101022.xml · nonDerivative · entry 12

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Atlas Venture Opportunity Fund II, L.P.

Disclosed balance after: 751,664

F4 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Opportunity Fund II, L.P. on February 25, 2025.

F8 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $30.95 to $31.30 inclusive.

F5 · ownership.nature: These shares are held directly by Atlas Venture Opportunity Fund II, L.P. ("AVOF II"). The general partner of AVOF II is Atlas Venture Associates Opportunity II, L.P. ("AVAO II LP"). Atlas Venture Associates Opportunity II, LLC ("AVAO II LLC") is the general partner of AVAO II LP. The Reporting Person is a member of AVAO II LLC and disclaims beneficial ownership of such securities held by AVOF II, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001451612-25-000008 · form4-10152025_101022.xml · nonDerivative · entry 11

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Atlas Venture Fund XI, L.P.

Disclosed balance after: 2,619,185

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund XI, L.P. on February 25, 2025.

F8 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $30.95 to $31.30 inclusive.

F3 · ownership.nature: These shares are held directly by Atlas Venture Fund XI, L.P. ("AVF XI "). The general partner of AVF XI is Atlas Venture Associates XI, L.P. ("AVA XI LP"). Atlas Venture Associates XI, LLC ("AVA XI LLC") is the general partner of AVA XI LP. The Reporting Person is a member of AVA XI LLC and disclaims beneficial ownership of such securities held by AVF XI, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001451612-25-000008 · form4-10152025_101022.xml · nonDerivative · entry 10

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Atlas Venture Opportunity Fund II, L.P.

Disclosed balance after: 757,967

F4 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Opportunity Fund II, L.P. on February 25, 2025.

F7 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $29.95 to $30.94 inclusive.

F5 · ownership.nature: These shares are held directly by Atlas Venture Opportunity Fund II, L.P. ("AVOF II"). The general partner of AVOF II is Atlas Venture Associates Opportunity II, L.P. ("AVAO II LP"). Atlas Venture Associates Opportunity II, LLC ("AVAO II LLC") is the general partner of AVAO II LP. The Reporting Person is a member of AVAO II LLC and disclaims beneficial ownership of such securities held by AVOF II, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001451612-25-000008 · form4-10152025_101022.xml · nonDerivative · entry 9

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Atlas Venture Fund XI, L.P.

Disclosed balance after: 2,649,217

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund XI, L.P. on February 25, 2025.

F7 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $29.95 to $30.94 inclusive.

F3 · ownership.nature: These shares are held directly by Atlas Venture Fund XI, L.P. ("AVF XI "). The general partner of AVF XI is Atlas Venture Associates XI, L.P. ("AVA XI LP"). Atlas Venture Associates XI, LLC ("AVA XI LLC") is the general partner of AVA XI LP. The Reporting Person is a member of AVA XI LLC and disclaims beneficial ownership of such securities held by AVF XI, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001451612-25-000008 · form4-10152025_101022.xml · nonDerivative · entry 8

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Atlas Venture Opportunity Fund II, L.P.

Disclosed balance after: 771,762

F4 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Opportunity Fund II, L.P. on February 25, 2025.

F5 · ownership.nature: These shares are held directly by Atlas Venture Opportunity Fund II, L.P. ("AVOF II"). The general partner of AVOF II is Atlas Venture Associates Opportunity II, L.P. ("AVAO II LP"). Atlas Venture Associates Opportunity II, LLC ("AVAO II LLC") is the general partner of AVAO II LP. The Reporting Person is a member of AVAO II LLC and disclaims beneficial ownership of such securities held by AVOF II, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001451612-25-000008 · form4-10152025_101022.xml · nonDerivative · entry 7

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Atlas Venture Fund XI, L.P.

Disclosed balance after: 2,714,943

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund XI, L.P. on February 25, 2025.

F3 · ownership.nature: These shares are held directly by Atlas Venture Fund XI, L.P. ("AVF XI "). The general partner of AVF XI is Atlas Venture Associates XI, L.P. ("AVA XI LP"). Atlas Venture Associates XI, LLC ("AVA XI LLC") is the general partner of AVA XI LP. The Reporting Person is a member of AVA XI LLC and disclaims beneficial ownership of such securities held by AVF XI, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001451612-25-000008 · form4-10152025_101022.xml · nonDerivative · entry 6

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Atlas Venture Opportunity Fund II, L.P.

Disclosed balance after: 771,867

F4 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Opportunity Fund II, L.P. on February 25, 2025.

F5 · ownership.nature: These shares are held directly by Atlas Venture Opportunity Fund II, L.P. ("AVOF II"). The general partner of AVOF II is Atlas Venture Associates Opportunity II, L.P. ("AVAO II LP"). Atlas Venture Associates Opportunity II, LLC ("AVAO II LLC") is the general partner of AVAO II LP. The Reporting Person is a member of AVAO II LLC and disclaims beneficial ownership of such securities held by AVOF II, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001451612-25-000008 · form4-10152025_101022.xml · nonDerivative · entry 5

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Atlas Venture Fund XI, L.P.

Disclosed balance after: 2,715,444

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund XI, L.P. on February 25, 2025.

F3 · ownership.nature: These shares are held directly by Atlas Venture Fund XI, L.P. ("AVF XI "). The general partner of AVF XI is Atlas Venture Associates XI, L.P. ("AVA XI LP"). Atlas Venture Associates XI, LLC ("AVA XI LLC") is the general partner of AVA XI LP. The Reporting Person is a member of AVA XI LLC and disclaims beneficial ownership of such securities held by AVF XI, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001451612-25-000008 · form4-10152025_101022.xml · nonDerivative · entry 4

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Atlas Venture Opportunity Fund II, L.P.

Disclosed balance after: 772,724

F4 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Opportunity Fund II, L.P. on February 25, 2025.

F6 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $29.95 to $30.93 inclusive.

F5 · ownership.nature: These shares are held directly by Atlas Venture Opportunity Fund II, L.P. ("AVOF II"). The general partner of AVOF II is Atlas Venture Associates Opportunity II, L.P. ("AVAO II LP"). Atlas Venture Associates Opportunity II, LLC ("AVAO II LLC") is the general partner of AVAO II LP. The Reporting Person is a member of AVAO II LLC and disclaims beneficial ownership of such securities held by AVOF II, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001451612-25-000008 · form4-10152025_101022.xml · nonDerivative · entry 3

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Atlas Venture Fund XI, L.P.

Disclosed balance after: 2,719,526

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund XI, L.P. on February 25, 2025.

F6 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $29.95 to $30.93 inclusive.

F3 · ownership.nature: These shares are held directly by Atlas Venture Fund XI, L.P. ("AVF XI "). The general partner of AVF XI is Atlas Venture Associates XI, L.P. ("AVA XI LP"). Atlas Venture Associates XI, LLC ("AVA XI LLC") is the general partner of AVA XI LP. The Reporting Person is a member of AVA XI LLC and disclaims beneficial ownership of such securities held by AVF XI, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001451612-25-000008 · form4-10152025_101022.xml · nonDerivative · entry 2

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Atlas Venture Opportunity Fund II, L.P.

Disclosed balance after: 781,969

F4 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Opportunity Fund II, L.P. on February 25, 2025.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $29.95 to $30.11 inclusive. The Reporting Persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnotes (2), (6), (7) and (8).

F5 · ownership.nature: These shares are held directly by Atlas Venture Opportunity Fund II, L.P. ("AVOF II"). The general partner of AVOF II is Atlas Venture Associates Opportunity II, L.P. ("AVAO II LP"). Atlas Venture Associates Opportunity II, LLC ("AVAO II LLC") is the general partner of AVAO II LP. The Reporting Person is a member of AVAO II LLC and disclaims beneficial ownership of such securities held by AVOF II, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001451612-25-000008 · form4-10152025_101022.xml · nonDerivative · entry 1

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Atlas Venture Fund XI, L.P.

Disclosed balance after: 2,763,574

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund XI, L.P. on February 25, 2025.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $29.95 to $30.11 inclusive. The Reporting Persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnotes (2), (6), (7) and (8).

F3 · ownership.nature: These shares are held directly by Atlas Venture Fund XI, L.P. ("AVF XI "). The general partner of AVF XI is Atlas Venture Associates XI, L.P. ("AVA XI LP"). Atlas Venture Associates XI, LLC ("AVA XI LLC") is the general partner of AVA XI LP. The Reporting Person is a member of AVA XI LLC and disclaims beneficial ownership of such securities held by AVF XI, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001451612-25-000006 · form4-10072025_091026.xml · nonDerivative · entry 4

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Atlas Venture Opportunity Fund II, L.P.

Disclosed balance after: 785,480

F4 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Opportunity Fund II, L.P. on February 25, 2025.

F6 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $29.95 to $30.00 inclusive.

F5 · ownership.nature: These shares are held directly by Atlas Venture Opportunity Fund II, L.P. ("AVOF II"). The general partner of AVOF II is Atlas Venture Associates Opportunity II, L.P. ("AVAO II LP"). Atlas Venture Associates Opportunity II, LLC ("AVAO II LLC") is the general partner of AVAO II LP. The Reporting Person is a member of AVAO II LLC and disclaims beneficial ownership of such securities held by AVOF II, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001451612-25-000006 · form4-10072025_091026.xml · nonDerivative · entry 3

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Atlas Venture Fund XI, L.P.

Disclosed balance after: 2,780,301

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund XI, L.P. on February 25, 2025.

F6 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $29.95 to $30.00 inclusive.

F3 · ownership.nature: These shares are held directly by Atlas Venture Fund XI, L.P. ("AVF XI "). The general partner of AVF XI is Atlas Venture Associates XI, L.P. ("AVA XI LP"). Atlas Venture Associates XI, LLC ("AVA XI LLC") is the general partner of AVA XI LP. The Reporting Person is a member of AVA XI LLC and disclaims beneficial ownership of such securities held by AVF XI, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001451612-25-000006 · form4-10072025_091026.xml · nonDerivative · entry 2

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Atlas Venture Opportunity Fund II, L.P.

Disclosed balance after: 787,527

F4 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Opportunity Fund II, L.P. on February 25, 2025.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $29.95 to $30.11 inclusive. The Reporting Persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnotes (2) and (6).

F5 · ownership.nature: These shares are held directly by Atlas Venture Opportunity Fund II, L.P. ("AVOF II"). The general partner of AVOF II is Atlas Venture Associates Opportunity II, L.P. ("AVAO II LP"). Atlas Venture Associates Opportunity II, LLC ("AVAO II LLC") is the general partner of AVAO II LP. The Reporting Person is a member of AVAO II LLC and disclaims beneficial ownership of such securities held by AVOF II, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001451612-25-000006 · form4-10072025_091026.xml · nonDerivative · entry 1

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Atlas Venture Fund XI, L.P.

Disclosed balance after: 2,790,054

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund XI, L.P. on February 25, 2025.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $29.95 to $30.11 inclusive. The Reporting Persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnotes (2) and (6).

F3 · ownership.nature: These shares are held directly by Atlas Venture Fund XI, L.P. ("AVF XI "). The general partner of AVF XI is Atlas Venture Associates XI, L.P. ("AVA XI LP"). Atlas Venture Associates XI, LLC ("AVA XI LLC") is the general partner of AVA XI LP. The Reporting Person is a member of AVA XI LLC and disclaims beneficial ownership of such securities held by AVF XI, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001451612-25-000004 · form4-10012025_101039.xml · nonDerivative · entry 6

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Atlas Venture Opportunity Fund II, L.P.

Disclosed balance after: 794,075

F4 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Opportunity Fund II, L.P. on February 25, 2025.

F5 · ownership.nature: These shares are held directly by Atlas Venture Opportunity Fund II, L.P. ("AVOF II"). The general partner of AVOF II is Atlas Venture Associates Opportunity II, L.P. ("AVAO II LP"). Atlas Venture Associates Opportunity II, LLC ("AVAO II LLC") is the general partner of AVAO II LP. The Reporting Person is a member of AVAO II LLC and disclaims beneficial ownership of such securities held by AVOF II, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001451612-25-000004 · form4-10012025_101039.xml · nonDerivative · entry 5

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Atlas Venture Fund XI, L.P.

Disclosed balance after: 2,821,252

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund XI, L.P. on February 25, 2025.

F3 · ownership.nature: These shares are held directly by Atlas Venture Fund XI, L.P. ("AVF XI "). The general partner of AVF XI is Atlas Venture Associates XI, L.P. ("AVA XI LP"). Atlas Venture Associates XI, LLC ("AVA XI LLC") is the general partner of AVA XI LP. The Reporting Person is a member of AVA XI LLC and disclaims beneficial ownership of such securities held by AVF XI, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001451612-25-000004 · form4-10012025_101039.xml · nonDerivative · entry 4

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Atlas Venture Opportunity Fund II, L.P.

Disclosed balance after: 794,110

F4 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Opportunity Fund II, L.P. on February 25, 2025.

F6 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $29.95 to $30.20 inclusive.

F5 · ownership.nature: These shares are held directly by Atlas Venture Opportunity Fund II, L.P. ("AVOF II"). The general partner of AVOF II is Atlas Venture Associates Opportunity II, L.P. ("AVAO II LP"). Atlas Venture Associates Opportunity II, LLC ("AVAO II LLC") is the general partner of AVAO II LP. The Reporting Person is a member of AVAO II LLC and disclaims beneficial ownership of such securities held by AVOF II, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001451612-25-000004 · form4-10012025_101039.xml · nonDerivative · entry 3

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Atlas Venture Fund XI, L.P.

Disclosed balance after: 2,821,417

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund XI, L.P. on February 25, 2025.

F6 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $29.95 to $30.20 inclusive.

F3 · ownership.nature: These shares are held directly by Atlas Venture Fund XI, L.P. ("AVF XI "). The general partner of AVF XI is Atlas Venture Associates XI, L.P. ("AVA XI LP"). Atlas Venture Associates XI, LLC ("AVA XI LLC") is the general partner of AVA XI LP. The Reporting Person is a member of AVA XI LLC and disclaims beneficial ownership of such securities held by AVF XI, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001451612-25-000004 · form4-10012025_101039.xml · nonDerivative · entry 2

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Atlas Venture Opportunity Fund II, L.P.

Disclosed balance after: 796,259

F4 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Opportunity Fund II, L.P. on February 25, 2025.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $29.95 to $30.41 inclusive. The Reporting Persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnotes (2) and (6).

F5 · ownership.nature: These shares are held directly by Atlas Venture Opportunity Fund II, L.P. ("AVOF II"). The general partner of AVOF II is Atlas Venture Associates Opportunity II, L.P. ("AVAO II LP"). Atlas Venture Associates Opportunity II, LLC ("AVAO II LLC") is the general partner of AVAO II LP. The Reporting Person is a member of AVAO II LLC and disclaims beneficial ownership of such securities held by AVOF II, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001451612-25-000004 · form4-10012025_101039.xml · nonDerivative · entry 1

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · By Atlas Venture Fund XI, L.P.

Disclosed balance after: 2,831,656

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund XI, L.P. on February 25, 2025.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $29.95 to $30.41 inclusive. The Reporting Persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnotes (2) and (6).

F3 · ownership.nature: These shares are held directly by Atlas Venture Fund XI, L.P. ("AVF XI "). The general partner of AVF XI is Atlas Venture Associates XI, L.P. ("AVA XI LP"). Atlas Venture Associates XI, LLC ("AVA XI LLC") is the general partner of AVA XI LP. The Reporting Person is a member of AVA XI LLC and disclaims beneficial ownership of such securities held by AVF XI, except to the extent of his pecuniary interest therein, if any.

SEC source: 0000950170-25-102492 · ownership.xml · derivative · entry 10

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 48,393 shares

Expires not disclosed

F1 · kind: This Form 4 reports securities disposed pursuant to the Agreement and Plan of Merger (the "Merger Agreement") by and among the Issuer, Sanofi ("Parent"), and Vesper Acquisition Sub Inc., a wholly owned subsidiary of Parent ("Merger Sub"). Pursuant to the terms of the Merger Agreement, on August 5, 2025 (the "Effective Time"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer continuing as the surviving corporation in the Merger and as a wholly owned subsidiary of Parent. At the Effective Time, each share of Issuer Common Stock issued and outstanding immediately prior to the Effective Time was converted into the right to receive (i) $8.00 per share of Common Stock in cash, without interest (the "Closing Amount") plus (ii) one contingent value right ("CVR"), representing the right to receive $2.00 payable in cash, conditioned upon satisfaction of a certain clinical milestone (together with the Closing Amount, the "Merger Consideration").

F5 · price: The shares are held directly by Atlas Venture Opportunity Fund I, L.P. ("Atlas Venture Opportunity Fund I"). The general partner of Atlas Venture Opportunity Fund I is Atlas Venture Associates Opportunity I, L.P. ("AVAO I LP"). Atlas Venture Associates Opportunity I, LLC ("AVAO I LLC") is the general partner of AVAO I LP. The Reporting Person is a member of AVAO I LLC and disclaims beneficial ownership of such securities held by Atlas Venture Opportunity Fund I, except to the extent of his pecuniary interest therein, if any.

F6 · derivative.exercise_date: Pursuant to the terms of the Merger Agreement, at the Effective Time, each stock option that was outstanding as of immediately prior to the Effective Time, to the extent unvested, was accelerated and became fully vested. Each stock option having an exercise price per share that was less than the Closing Amount was cancelled and converted into the right to receive (i) an amount, without interest, equal to the product of (a) the total number of shares subject to such option immediately prior to the Effective Time, multiplied by (b) the excess of (1) the Closing Amount over (2) the exercise price per share under such option and (ii) one CVR for each share subject to such option.

F6 · derivative.expiration_date: Pursuant to the terms of the Merger Agreement, at the Effective Time, each stock option that was outstanding as of immediately prior to the Effective Time, to the extent unvested, was accelerated and became fully vested. Each stock option having an exercise price per share that was less than the Closing Amount was cancelled and converted into the right to receive (i) an amount, without interest, equal to the product of (a) the total number of shares subject to such option immediately prior to the Effective Time, multiplied by (b) the excess of (1) the Closing Amount over (2) the exercise price per share under such option and (ii) one CVR for each share subject to such option.

F3 · ownership.direct: The Reporting Person is a member of Atlas Venture Associates XII, LLC and is obligated to transfer the economic benefit, if any, received upon the sale of the shares issuable upon settlement of this award 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: 0000950170-25-102492 · ownership.xml · derivative · entry 9

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 18,068 shares

Expires not disclosed

F1 · kind: This Form 4 reports securities disposed pursuant to the Agreement and Plan of Merger (the "Merger Agreement") by and among the Issuer, Sanofi ("Parent"), and Vesper Acquisition Sub Inc., a wholly owned subsidiary of Parent ("Merger Sub"). Pursuant to the terms of the Merger Agreement, on August 5, 2025 (the "Effective Time"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer continuing as the surviving corporation in the Merger and as a wholly owned subsidiary of Parent. At the Effective Time, each share of Issuer Common Stock issued and outstanding immediately prior to the Effective Time was converted into the right to receive (i) $8.00 per share of Common Stock in cash, without interest (the "Closing Amount") plus (ii) one contingent value right ("CVR"), representing the right to receive $2.00 payable in cash, conditioned upon satisfaction of a certain clinical milestone (together with the Closing Amount, the "Merger Consideration").

F5 · price: The shares are held directly by Atlas Venture Opportunity Fund I, L.P. ("Atlas Venture Opportunity Fund I"). The general partner of Atlas Venture Opportunity Fund I is Atlas Venture Associates Opportunity I, L.P. ("AVAO I LP"). Atlas Venture Associates Opportunity I, LLC ("AVAO I LLC") is the general partner of AVAO I LP. The Reporting Person is a member of AVAO I LLC and disclaims beneficial ownership of such securities held by Atlas Venture Opportunity Fund I, except to the extent of his pecuniary interest therein, if any.

F6 · derivative.exercise_date: Pursuant to the terms of the Merger Agreement, at the Effective Time, each stock option that was outstanding as of immediately prior to the Effective Time, to the extent unvested, was accelerated and became fully vested. Each stock option having an exercise price per share that was less than the Closing Amount was cancelled and converted into the right to receive (i) an amount, without interest, equal to the product of (a) the total number of shares subject to such option immediately prior to the Effective Time, multiplied by (b) the excess of (1) the Closing Amount over (2) the exercise price per share under such option and (ii) one CVR for each share subject to such option.

F6 · derivative.expiration_date: Pursuant to the terms of the Merger Agreement, at the Effective Time, each stock option that was outstanding as of immediately prior to the Effective Time, to the extent unvested, was accelerated and became fully vested. Each stock option having an exercise price per share that was less than the Closing Amount was cancelled and converted into the right to receive (i) an amount, without interest, equal to the product of (a) the total number of shares subject to such option immediately prior to the Effective Time, multiplied by (b) the excess of (1) the Closing Amount over (2) the exercise price per share under such option and (ii) one CVR for each share subject to such option.

F3 · ownership.direct: The Reporting Person is a member of Atlas Venture Associates XII, LLC and is obligated to transfer the economic benefit, if any, received upon the sale of the shares issuable upon settlement of this award 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: 0000950170-25-102492 · ownership.xml · derivative · entry 8

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 34,612 shares

Expires not disclosed

F1 · kind: This Form 4 reports securities disposed pursuant to the Agreement and Plan of Merger (the "Merger Agreement") by and among the Issuer, Sanofi ("Parent"), and Vesper Acquisition Sub Inc., a wholly owned subsidiary of Parent ("Merger Sub"). Pursuant to the terms of the Merger Agreement, on August 5, 2025 (the "Effective Time"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer continuing as the surviving corporation in the Merger and as a wholly owned subsidiary of Parent. At the Effective Time, each share of Issuer Common Stock issued and outstanding immediately prior to the Effective Time was converted into the right to receive (i) $8.00 per share of Common Stock in cash, without interest (the "Closing Amount") plus (ii) one contingent value right ("CVR"), representing the right to receive $2.00 payable in cash, conditioned upon satisfaction of a certain clinical milestone (together with the Closing Amount, the "Merger Consideration").

F5 · price: The shares are held directly by Atlas Venture Opportunity Fund I, L.P. ("Atlas Venture Opportunity Fund I"). The general partner of Atlas Venture Opportunity Fund I is Atlas Venture Associates Opportunity I, L.P. ("AVAO I LP"). Atlas Venture Associates Opportunity I, LLC ("AVAO I LLC") is the general partner of AVAO I LP. The Reporting Person is a member of AVAO I LLC and disclaims beneficial ownership of such securities held by Atlas Venture Opportunity Fund I, except to the extent of his pecuniary interest therein, if any.

F6 · derivative.exercise_date: Pursuant to the terms of the Merger Agreement, at the Effective Time, each stock option that was outstanding as of immediately prior to the Effective Time, to the extent unvested, was accelerated and became fully vested. Each stock option having an exercise price per share that was less than the Closing Amount was cancelled and converted into the right to receive (i) an amount, without interest, equal to the product of (a) the total number of shares subject to such option immediately prior to the Effective Time, multiplied by (b) the excess of (1) the Closing Amount over (2) the exercise price per share under such option and (ii) one CVR for each share subject to such option.

F6 · derivative.expiration_date: Pursuant to the terms of the Merger Agreement, at the Effective Time, each stock option that was outstanding as of immediately prior to the Effective Time, to the extent unvested, was accelerated and became fully vested. Each stock option having an exercise price per share that was less than the Closing Amount was cancelled and converted into the right to receive (i) an amount, without interest, equal to the product of (a) the total number of shares subject to such option immediately prior to the Effective Time, multiplied by (b) the excess of (1) the Closing Amount over (2) the exercise price per share under such option and (ii) one CVR for each share subject to such option.

F3 · ownership.direct: The Reporting Person is a member of Atlas Venture Associates XII, LLC and is obligated to transfer the economic benefit, if any, received upon the sale of the shares issuable upon settlement of this award 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: 0000950170-25-102492 · ownership.xml · derivative · entry 7

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 13,928 shares

Expires not disclosed

F1 · kind: This Form 4 reports securities disposed pursuant to the Agreement and Plan of Merger (the "Merger Agreement") by and among the Issuer, Sanofi ("Parent"), and Vesper Acquisition Sub Inc., a wholly owned subsidiary of Parent ("Merger Sub"). Pursuant to the terms of the Merger Agreement, on August 5, 2025 (the "Effective Time"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer continuing as the surviving corporation in the Merger and as a wholly owned subsidiary of Parent. At the Effective Time, each share of Issuer Common Stock issued and outstanding immediately prior to the Effective Time was converted into the right to receive (i) $8.00 per share of Common Stock in cash, without interest (the "Closing Amount") plus (ii) one contingent value right ("CVR"), representing the right to receive $2.00 payable in cash, conditioned upon satisfaction of a certain clinical milestone (together with the Closing Amount, the "Merger Consideration").

F5 · price: The shares are held directly by Atlas Venture Opportunity Fund I, L.P. ("Atlas Venture Opportunity Fund I"). The general partner of Atlas Venture Opportunity Fund I is Atlas Venture Associates Opportunity I, L.P. ("AVAO I LP"). Atlas Venture Associates Opportunity I, LLC ("AVAO I LLC") is the general partner of AVAO I LP. The Reporting Person is a member of AVAO I LLC and disclaims beneficial ownership of such securities held by Atlas Venture Opportunity Fund I, except to the extent of his pecuniary interest therein, if any.

F6 · derivative.exercise_date: Pursuant to the terms of the Merger Agreement, at the Effective Time, each stock option that was outstanding as of immediately prior to the Effective Time, to the extent unvested, was accelerated and became fully vested. Each stock option having an exercise price per share that was less than the Closing Amount was cancelled and converted into the right to receive (i) an amount, without interest, equal to the product of (a) the total number of shares subject to such option immediately prior to the Effective Time, multiplied by (b) the excess of (1) the Closing Amount over (2) the exercise price per share under such option and (ii) one CVR for each share subject to such option.

F6 · derivative.expiration_date: Pursuant to the terms of the Merger Agreement, at the Effective Time, each stock option that was outstanding as of immediately prior to the Effective Time, to the extent unvested, was accelerated and became fully vested. Each stock option having an exercise price per share that was less than the Closing Amount was cancelled and converted into the right to receive (i) an amount, without interest, equal to the product of (a) the total number of shares subject to such option immediately prior to the Effective Time, multiplied by (b) the excess of (1) the Closing Amount over (2) the exercise price per share under such option and (ii) one CVR for each share subject to such option.

F3 · ownership.direct: The Reporting Person is a member of Atlas Venture Associates XII, LLC and is obligated to transfer the economic benefit, if any, received upon the sale of the shares issuable upon settlement of this award 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: 0000950170-25-102492 · ownership.xml · derivative · entry 6

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 9,713 shares

Expires not disclosed

F1 · kind: This Form 4 reports securities disposed pursuant to the Agreement and Plan of Merger (the "Merger Agreement") by and among the Issuer, Sanofi ("Parent"), and Vesper Acquisition Sub Inc., a wholly owned subsidiary of Parent ("Merger Sub"). Pursuant to the terms of the Merger Agreement, on August 5, 2025 (the "Effective Time"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer continuing as the surviving corporation in the Merger and as a wholly owned subsidiary of Parent. At the Effective Time, each share of Issuer Common Stock issued and outstanding immediately prior to the Effective Time was converted into the right to receive (i) $8.00 per share of Common Stock in cash, without interest (the "Closing Amount") plus (ii) one contingent value right ("CVR"), representing the right to receive $2.00 payable in cash, conditioned upon satisfaction of a certain clinical milestone (together with the Closing Amount, the "Merger Consideration").

F5 · price: The shares are held directly by Atlas Venture Opportunity Fund I, L.P. ("Atlas Venture Opportunity Fund I"). The general partner of Atlas Venture Opportunity Fund I is Atlas Venture Associates Opportunity I, L.P. ("AVAO I LP"). Atlas Venture Associates Opportunity I, LLC ("AVAO I LLC") is the general partner of AVAO I LP. The Reporting Person is a member of AVAO I LLC and disclaims beneficial ownership of such securities held by Atlas Venture Opportunity Fund I, except to the extent of his pecuniary interest therein, if any.

F6 · derivative.exercise_date: Pursuant to the terms of the Merger Agreement, at the Effective Time, each stock option that was outstanding as of immediately prior to the Effective Time, to the extent unvested, was accelerated and became fully vested. Each stock option having an exercise price per share that was less than the Closing Amount was cancelled and converted into the right to receive (i) an amount, without interest, equal to the product of (a) the total number of shares subject to such option immediately prior to the Effective Time, multiplied by (b) the excess of (1) the Closing Amount over (2) the exercise price per share under such option and (ii) one CVR for each share subject to such option.

F6 · derivative.expiration_date: Pursuant to the terms of the Merger Agreement, at the Effective Time, each stock option that was outstanding as of immediately prior to the Effective Time, to the extent unvested, was accelerated and became fully vested. Each stock option having an exercise price per share that was less than the Closing Amount was cancelled and converted into the right to receive (i) an amount, without interest, equal to the product of (a) the total number of shares subject to such option immediately prior to the Effective Time, multiplied by (b) the excess of (1) the Closing Amount over (2) the exercise price per share under such option and (ii) one CVR for each share subject to such option.

F3 · ownership.direct: The Reporting Person is a member of Atlas Venture Associates XII, LLC and is obligated to transfer the economic benefit, if any, received upon the sale of the shares issuable upon settlement of this award 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: 0000950170-25-102492 · ownership.xml · derivative · entry 5

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 12,155 shares

Expires not disclosed

F1 · kind: This Form 4 reports securities disposed pursuant to the Agreement and Plan of Merger (the "Merger Agreement") by and among the Issuer, Sanofi ("Parent"), and Vesper Acquisition Sub Inc., a wholly owned subsidiary of Parent ("Merger Sub"). Pursuant to the terms of the Merger Agreement, on August 5, 2025 (the "Effective Time"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer continuing as the surviving corporation in the Merger and as a wholly owned subsidiary of Parent. At the Effective Time, each share of Issuer Common Stock issued and outstanding immediately prior to the Effective Time was converted into the right to receive (i) $8.00 per share of Common Stock in cash, without interest (the "Closing Amount") plus (ii) one contingent value right ("CVR"), representing the right to receive $2.00 payable in cash, conditioned upon satisfaction of a certain clinical milestone (together with the Closing Amount, the "Merger Consideration").

F5 · price: The shares are held directly by Atlas Venture Opportunity Fund I, L.P. ("Atlas Venture Opportunity Fund I"). The general partner of Atlas Venture Opportunity Fund I is Atlas Venture Associates Opportunity I, L.P. ("AVAO I LP"). Atlas Venture Associates Opportunity I, LLC ("AVAO I LLC") is the general partner of AVAO I LP. The Reporting Person is a member of AVAO I LLC and disclaims beneficial ownership of such securities held by Atlas Venture Opportunity Fund I, except to the extent of his pecuniary interest therein, if any.

F6 · derivative.exercise_date: Pursuant to the terms of the Merger Agreement, at the Effective Time, each stock option that was outstanding as of immediately prior to the Effective Time, to the extent unvested, was accelerated and became fully vested. Each stock option having an exercise price per share that was less than the Closing Amount was cancelled and converted into the right to receive (i) an amount, without interest, equal to the product of (a) the total number of shares subject to such option immediately prior to the Effective Time, multiplied by (b) the excess of (1) the Closing Amount over (2) the exercise price per share under such option and (ii) one CVR for each share subject to such option.

F6 · derivative.expiration_date: Pursuant to the terms of the Merger Agreement, at the Effective Time, each stock option that was outstanding as of immediately prior to the Effective Time, to the extent unvested, was accelerated and became fully vested. Each stock option having an exercise price per share that was less than the Closing Amount was cancelled and converted into the right to receive (i) an amount, without interest, equal to the product of (a) the total number of shares subject to such option immediately prior to the Effective Time, multiplied by (b) the excess of (1) the Closing Amount over (2) the exercise price per share under such option and (ii) one CVR for each share subject to such option.

F3 · ownership.direct: The Reporting Person is a member of Atlas Venture Associates XII, LLC and is obligated to transfer the economic benefit, if any, received upon the sale of the shares issuable upon settlement of this award 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: 0000950170-25-102492 · ownership.xml · derivative · entry 4

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 7,577 shares

Expires not disclosed

F1 · kind: This Form 4 reports securities disposed pursuant to the Agreement and Plan of Merger (the "Merger Agreement") by and among the Issuer, Sanofi ("Parent"), and Vesper Acquisition Sub Inc., a wholly owned subsidiary of Parent ("Merger Sub"). Pursuant to the terms of the Merger Agreement, on August 5, 2025 (the "Effective Time"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer continuing as the surviving corporation in the Merger and as a wholly owned subsidiary of Parent. At the Effective Time, each share of Issuer Common Stock issued and outstanding immediately prior to the Effective Time was converted into the right to receive (i) $8.00 per share of Common Stock in cash, without interest (the "Closing Amount") plus (ii) one contingent value right ("CVR"), representing the right to receive $2.00 payable in cash, conditioned upon satisfaction of a certain clinical milestone (together with the Closing Amount, the "Merger Consideration").

F5 · price: The shares are held directly by Atlas Venture Opportunity Fund I, L.P. ("Atlas Venture Opportunity Fund I"). The general partner of Atlas Venture Opportunity Fund I is Atlas Venture Associates Opportunity I, L.P. ("AVAO I LP"). Atlas Venture Associates Opportunity I, LLC ("AVAO I LLC") is the general partner of AVAO I LP. The Reporting Person is a member of AVAO I LLC and disclaims beneficial ownership of such securities held by Atlas Venture Opportunity Fund I, except to the extent of his pecuniary interest therein, if any.

F6 · derivative.exercise_date: Pursuant to the terms of the Merger Agreement, at the Effective Time, each stock option that was outstanding as of immediately prior to the Effective Time, to the extent unvested, was accelerated and became fully vested. Each stock option having an exercise price per share that was less than the Closing Amount was cancelled and converted into the right to receive (i) an amount, without interest, equal to the product of (a) the total number of shares subject to such option immediately prior to the Effective Time, multiplied by (b) the excess of (1) the Closing Amount over (2) the exercise price per share under such option and (ii) one CVR for each share subject to such option.

F6 · derivative.expiration_date: Pursuant to the terms of the Merger Agreement, at the Effective Time, each stock option that was outstanding as of immediately prior to the Effective Time, to the extent unvested, was accelerated and became fully vested. Each stock option having an exercise price per share that was less than the Closing Amount was cancelled and converted into the right to receive (i) an amount, without interest, equal to the product of (a) the total number of shares subject to such option immediately prior to the Effective Time, multiplied by (b) the excess of (1) the Closing Amount over (2) the exercise price per share under such option and (ii) one CVR for each share subject to such option.

F3 · ownership.direct: The Reporting Person is a member of Atlas Venture Associates XII, LLC and is obligated to transfer the economic benefit, if any, received upon the sale of the shares issuable upon settlement of this award 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: 0000950170-25-102492 · ownership.xml · nonDerivative · entry 3

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · By Atlas Venture Opportunity Fund I, L.P.

Disclosed balance after: 0

F1 · kind: This Form 4 reports securities disposed pursuant to the Agreement and Plan of Merger (the "Merger Agreement") by and among the Issuer, Sanofi ("Parent"), and Vesper Acquisition Sub Inc., a wholly owned subsidiary of Parent ("Merger Sub"). Pursuant to the terms of the Merger Agreement, on August 5, 2025 (the "Effective Time"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer continuing as the surviving corporation in the Merger and as a wholly owned subsidiary of Parent. At the Effective Time, each share of Issuer Common Stock issued and outstanding immediately prior to the Effective Time was converted into the right to receive (i) $8.00 per share of Common Stock in cash, without interest (the "Closing Amount") plus (ii) one contingent value right ("CVR"), representing the right to receive $2.00 payable in cash, conditioned upon satisfaction of a certain clinical milestone (together with the Closing Amount, the "Merger Consideration").

F1 · price: This Form 4 reports securities disposed pursuant to the Agreement and Plan of Merger (the "Merger Agreement") by and among the Issuer, Sanofi ("Parent"), and Vesper Acquisition Sub Inc., a wholly owned subsidiary of Parent ("Merger Sub"). Pursuant to the terms of the Merger Agreement, on August 5, 2025 (the "Effective Time"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer continuing as the surviving corporation in the Merger and as a wholly owned subsidiary of Parent. At the Effective Time, each share of Issuer Common Stock issued and outstanding immediately prior to the Effective Time was converted into the right to receive (i) $8.00 per share of Common Stock in cash, without interest (the "Closing Amount") plus (ii) one contingent value right ("CVR"), representing the right to receive $2.00 payable in cash, conditioned upon satisfaction of a certain clinical milestone (together with the Closing Amount, the "Merger Consideration").

F5 · ownership.nature: The shares are held directly by Atlas Venture Opportunity Fund I, L.P. ("Atlas Venture Opportunity Fund I"). The general partner of Atlas Venture Opportunity Fund I is Atlas Venture Associates Opportunity I, L.P. ("AVAO I LP"). Atlas Venture Associates Opportunity I, LLC ("AVAO I LLC") is the general partner of AVAO I LP. The Reporting Person is a member of AVAO I LLC and disclaims beneficial ownership of such securities held by Atlas Venture Opportunity Fund I, except to the extent of his pecuniary interest therein, if any.

SEC source: 0000950170-25-102492 · ownership.xml · nonDerivative · entry 2

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · By Atlas Venture Fund XII, L.P.

Disclosed balance after: 0

F1 · kind: This Form 4 reports securities disposed pursuant to the Agreement and Plan of Merger (the "Merger Agreement") by and among the Issuer, Sanofi ("Parent"), and Vesper Acquisition Sub Inc., a wholly owned subsidiary of Parent ("Merger Sub"). Pursuant to the terms of the Merger Agreement, on August 5, 2025 (the "Effective Time"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer continuing as the surviving corporation in the Merger and as a wholly owned subsidiary of Parent. At the Effective Time, each share of Issuer Common Stock issued and outstanding immediately prior to the Effective Time was converted into the right to receive (i) $8.00 per share of Common Stock in cash, without interest (the "Closing Amount") plus (ii) one contingent value right ("CVR"), representing the right to receive $2.00 payable in cash, conditioned upon satisfaction of a certain clinical milestone (together with the Closing Amount, the "Merger Consideration").

F1 · price: This Form 4 reports securities disposed pursuant to the Agreement and Plan of Merger (the "Merger Agreement") by and among the Issuer, Sanofi ("Parent"), and Vesper Acquisition Sub Inc., a wholly owned subsidiary of Parent ("Merger Sub"). Pursuant to the terms of the Merger Agreement, on August 5, 2025 (the "Effective Time"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer continuing as the surviving corporation in the Merger and as a wholly owned subsidiary of Parent. At the Effective Time, each share of Issuer Common Stock issued and outstanding immediately prior to the Effective Time was converted into the right to receive (i) $8.00 per share of Common Stock in cash, without interest (the "Closing Amount") plus (ii) one contingent value right ("CVR"), representing the right to receive $2.00 payable in cash, conditioned upon satisfaction of a certain clinical milestone (together with the Closing Amount, the "Merger Consideration").

F4 · ownership.nature: These shares are held directly by Atlas Venture Fund XII, L.P. ("Atlas Venture Fund XII"). The general partner of Atlas Venture Fund XII is Atlas Venture Associates XII, L.P. ("AVA XII LP"). Atlas Venture Associates XII, LLC ("AVA XII LLC") is the general partner of AVA XII LP. The Reporting Person is a member of AVA XII LLC and disclaims beneficial ownership of such securities held by Atlas Venture Fund XII, except to the extent of his pecuniary interest therein, if any.

SEC source: 0000950170-25-102492 · ownership.xml · nonDerivative · entry 1

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

F1 · kind: This Form 4 reports securities disposed pursuant to the Agreement and Plan of Merger (the "Merger Agreement") by and among the Issuer, Sanofi ("Parent"), and Vesper Acquisition Sub Inc., a wholly owned subsidiary of Parent ("Merger Sub"). Pursuant to the terms of the Merger Agreement, on August 5, 2025 (the "Effective Time"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer continuing as the surviving corporation in the Merger and as a wholly owned subsidiary of Parent. At the Effective Time, each share of Issuer Common Stock issued and outstanding immediately prior to the Effective Time was converted into the right to receive (i) $8.00 per share of Common Stock in cash, without interest (the "Closing Amount") plus (ii) one contingent value right ("CVR"), representing the right to receive $2.00 payable in cash, conditioned upon satisfaction of a certain clinical milestone (together with the Closing Amount, the "Merger Consideration").

F2 · shares: Represents Restricted Stock Units ("RSUs"), each of which represented the contingent right to receive one share of the Common Stock. Pursuant to the terms of the Merger Agreement, at the Effective Time, each RSU that is outstanding as of immediately prior to the Effective Time, to the extent unvested, was accelerated and became fully vested, and was cancelled and converted into the right to receive (i) an amount, without interest, equal to the product of (a) the total number of shares subject to such RSU immediately prior to the Effective Time, multiplied by (b) the Closing Amount and (ii) one CVR for each share subject to such RSU.

F1 · price: This Form 4 reports securities disposed pursuant to the Agreement and Plan of Merger (the "Merger Agreement") by and among the Issuer, Sanofi ("Parent"), and Vesper Acquisition Sub Inc., a wholly owned subsidiary of Parent ("Merger Sub"). Pursuant to the terms of the Merger Agreement, on August 5, 2025 (the "Effective Time"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer continuing as the surviving corporation in the Merger and as a wholly owned subsidiary of Parent. At the Effective Time, each share of Issuer Common Stock issued and outstanding immediately prior to the Effective Time was converted into the right to receive (i) $8.00 per share of Common Stock in cash, without interest (the "Closing Amount") plus (ii) one contingent value right ("CVR"), representing the right to receive $2.00 payable in cash, conditioned upon satisfaction of a certain clinical milestone (together with the Closing Amount, the "Merger Consideration").

F2 · price: Represents Restricted Stock Units ("RSUs"), each of which represented the contingent right to receive one share of the Common Stock. Pursuant to the terms of the Merger Agreement, at the Effective Time, each RSU that is outstanding as of immediately prior to the Effective Time, to the extent unvested, was accelerated and became fully vested, and was cancelled and converted into the right to receive (i) an amount, without interest, equal to the product of (a) the total number of shares subject to such RSU immediately prior to the Effective Time, multiplied by (b) the Closing Amount and (ii) one CVR for each share subject to such RSU.

F3 · ownership.direct: The Reporting Person is a member of Atlas Venture Associates XII, LLC and is obligated to transfer the economic benefit, if any, received upon the sale of the shares issuable upon settlement of this award 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: 0000950170-25-090581 · ownership.xml · derivative · entry 1

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 16,000

Underlying: Common Stock · 16,000 shares

Expires 2035-06-24

F1 · derivative.exercise_date: The shares underlying this stock option shall vest in full upon the earlier to occur of (i) June 25, 2026 and (ii) the date of the next annual meeting of the Issuer's stockholders.

F2 · ownership.direct: This option was granted to the Reporting Person, a director of the Issuer. The proceeds of any sale of shares of common stock issued to the Reporting Person upon exercise of this option will be transferred to Atlas Venture Life Science Advisors, LLC and as such, the Reporting Person disclaims ownership of such 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: 0002036042-25-000027 · edgardoc.xml · derivative · entry 1

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 19,959

Underlying: Common Stock · 19,959 shares

Expires 2035-06-11

F1 · security: This option was granted to the Reporting Person, a director of the Issuer. The proceeds of any sale of shares of common stock issued to the Reporting Person upon exercise of this option will be transferred to Atlas Venture Life Science Advisors, LLC and as such, the Reporting Person disclaims ownership of such 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.

F2 · derivative.exercise_date: This option vests in full upon the earlier of June 12, 2026 or the date of the next annual meeting of Sionna Therapeutics, Inc., subject to the Reporting Person's continued service on such vesting date.

SEC source: 0000950170-25-077278 · ownership.xml · nonDerivative · entry 1

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 5,000

F1 · shares: The shares reported in this transaction represent Restricted Stock Units ("RSUs") issued under the Issuer's 2021 Stock Option and Incentive Plan. Each RSU represents the contingent right to receive one share of the Issuer's Common Stock. The shares shall vest upon the earlier to occur of (i) May 22, 2026 and (ii) the next annual meeting of the Issuer's stockholders.

F2 · ownership.direct: The Reporting Person is a member of Atlas Venture Associates XII, LLC and is obligated to transfer the economic benefit, if any, received upon the sale of the shares issuable upon settlement of this RSU award 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: 0000950170-25-032390 · ownership.xml · derivative · entry 1

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 48,393

Underlying: Common Stock · 48,393 shares

Expires 2035-03-03

F1 · derivative.exercise_date: This stock option award was issued pursuant to the Issuer's Non-Employee Director Compensation Policy in lieu of cash compensation, and the shares subject to this award vest and become exercisable in four equal quarterly installments on the last day of each calendar quarter occurring hereafter, with the first installment vesting on March 31, 2025.

F2 · ownership.direct: The Reporting Person is a member of Atlas Venture Associates XII, LLC and is obligated to transfer the economic benefit, if any, received upon the sale of the shares issuable upon exercise of this stock option award 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: 0000950170-25-017029 · ownership.xml · derivative · entry 8

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · By Atlas Venture Opportunity Fund II, L.P.

Disclosed balance after: 0

Underlying: Common Stock · 747,727 shares

Expires not disclosed

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

F1 · derivative.exercise_price: Each share of Series Seed convertible preferred stock, Series A convertible preferred stock, Series B convertible preferred stock and Series C convertible preferred stock (collectively, the "Preferred Stock") automatically converted into shares of the Issuer's Common Stock on a one-for-1.4611 basis upon the closing of the Issuer's initial public offering on February 10, 2025. The Preferred Stock had no expiration date.

F1 · derivative.exercise_date: Each share of Series Seed convertible preferred stock, Series A convertible preferred stock, Series B convertible preferred stock and Series C convertible preferred stock (collectively, the "Preferred Stock") automatically converted into shares of the Issuer's Common Stock on a one-for-1.4611 basis upon the closing of the Issuer's initial public offering on February 10, 2025. The Preferred Stock had no expiration date.

F1 · derivative.expiration_date: Each share of Series Seed convertible preferred stock, Series A convertible preferred stock, Series B convertible preferred stock and Series C convertible preferred stock (collectively, the "Preferred Stock") automatically converted into shares of the Issuer's Common Stock on a one-for-1.4611 basis upon the closing of the Issuer's initial public offering on February 10, 2025. The Preferred Stock had no expiration date.

F3 · ownership.nature: These shares are held directly by Atlas Venture Opportunity Fund II, L.P. ("AVOF II"). The general partner of AVOF II is Atlas Venture Associates Opportunity II, L.P. ("AVAO II LP"). Atlas Venture Associates Opportunity II, LLC ("AVAO II LLC") is the general partner of AVAO II LP. The Reporting Person is a member of AVAO II LLC and disclaims beneficial ownership of such securities held by AVOF II, except to the extent of his pecuniary interest therein, if any.

SEC source: 0000950170-25-017029 · ownership.xml · derivative · entry 7

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · By Atlas Venture Fund XI, L.P.

Disclosed balance after: 0

Underlying: Common Stock · 42,068 shares

Expires not disclosed

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

F1 · derivative.exercise_price: Each share of Series Seed convertible preferred stock, Series A convertible preferred stock, Series B convertible preferred stock and Series C convertible preferred stock (collectively, the "Preferred Stock") automatically converted into shares of the Issuer's Common Stock on a one-for-1.4611 basis upon the closing of the Issuer's initial public offering on February 10, 2025. The Preferred Stock had no expiration date.

F1 · derivative.exercise_date: Each share of Series Seed convertible preferred stock, Series A convertible preferred stock, Series B convertible preferred stock and Series C convertible preferred stock (collectively, the "Preferred Stock") automatically converted into shares of the Issuer's Common Stock on a one-for-1.4611 basis upon the closing of the Issuer's initial public offering on February 10, 2025. The Preferred Stock had no expiration date.

F1 · derivative.expiration_date: Each share of Series Seed convertible preferred stock, Series A convertible preferred stock, Series B convertible preferred stock and Series C convertible preferred stock (collectively, the "Preferred Stock") automatically converted into shares of the Issuer's Common Stock on a one-for-1.4611 basis upon the closing of the Issuer's initial public offering on February 10, 2025. The Preferred Stock had no expiration date.

F2 · ownership.nature: These shares are held directly by Atlas Venture Fund XI, L.P. ("AVF XI "). The general partner of AVF XI is Atlas Venture Associates XI, L.P. ("AVA XI LP"). Atlas Venture Associates XI, LLC ("AVA XI LLC") is the general partner of AVA XI LP. The Reporting Person is a member of AVA XI LLC and disclaims beneficial ownership of such securities held by AVF XI, except to the extent of his pecuniary interest therein, if any.

SEC source: 0000950170-25-017029 · ownership.xml · derivative · entry 6

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · By Atlas Venture Fund XI, L.P.

Disclosed balance after: 0

Underlying: Common Stock · 888,599 shares

Expires not disclosed

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

F1 · derivative.exercise_price: Each share of Series Seed convertible preferred stock, Series A convertible preferred stock, Series B convertible preferred stock and Series C convertible preferred stock (collectively, the "Preferred Stock") automatically converted into shares of the Issuer's Common Stock on a one-for-1.4611 basis upon the closing of the Issuer's initial public offering on February 10, 2025. The Preferred Stock had no expiration date.

F1 · derivative.exercise_date: Each share of Series Seed convertible preferred stock, Series A convertible preferred stock, Series B convertible preferred stock and Series C convertible preferred stock (collectively, the "Preferred Stock") automatically converted into shares of the Issuer's Common Stock on a one-for-1.4611 basis upon the closing of the Issuer's initial public offering on February 10, 2025. The Preferred Stock had no expiration date.

F1 · derivative.expiration_date: Each share of Series Seed convertible preferred stock, Series A convertible preferred stock, Series B convertible preferred stock and Series C convertible preferred stock (collectively, the "Preferred Stock") automatically converted into shares of the Issuer's Common Stock on a one-for-1.4611 basis upon the closing of the Issuer's initial public offering on February 10, 2025. The Preferred Stock had no expiration date.

F2 · ownership.nature: These shares are held directly by Atlas Venture Fund XI, L.P. ("AVF XI "). The general partner of AVF XI is Atlas Venture Associates XI, L.P. ("AVA XI LP"). Atlas Venture Associates XI, LLC ("AVA XI LLC") is the general partner of AVA XI LP. The Reporting Person is a member of AVA XI LLC and disclaims beneficial ownership of such securities held by AVF XI, except to the extent of his pecuniary interest therein, if any.

SEC source: 0000950170-25-017029 · ownership.xml · derivative · entry 5

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · By Atlas Venture Fund XI, L.P.

Disclosed balance after: 0

Underlying: Common Stock · 1,236,271 shares

Expires not disclosed

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

F1 · derivative.exercise_price: Each share of Series Seed convertible preferred stock, Series A convertible preferred stock, Series B convertible preferred stock and Series C convertible preferred stock (collectively, the "Preferred Stock") automatically converted into shares of the Issuer's Common Stock on a one-for-1.4611 basis upon the closing of the Issuer's initial public offering on February 10, 2025. The Preferred Stock had no expiration date.

F1 · derivative.exercise_date: Each share of Series Seed convertible preferred stock, Series A convertible preferred stock, Series B convertible preferred stock and Series C convertible preferred stock (collectively, the "Preferred Stock") automatically converted into shares of the Issuer's Common Stock on a one-for-1.4611 basis upon the closing of the Issuer's initial public offering on February 10, 2025. The Preferred Stock had no expiration date.

F1 · derivative.expiration_date: Each share of Series Seed convertible preferred stock, Series A convertible preferred stock, Series B convertible preferred stock and Series C convertible preferred stock (collectively, the "Preferred Stock") automatically converted into shares of the Issuer's Common Stock on a one-for-1.4611 basis upon the closing of the Issuer's initial public offering on February 10, 2025. The Preferred Stock had no expiration date.

F2 · ownership.nature: These shares are held directly by Atlas Venture Fund XI, L.P. ("AVF XI "). The general partner of AVF XI is Atlas Venture Associates XI, L.P. ("AVA XI LP"). Atlas Venture Associates XI, LLC ("AVA XI LLC") is the general partner of AVA XI LP. The Reporting Person is a member of AVA XI LLC and disclaims beneficial ownership of such securities held by AVF XI, except to the extent of his pecuniary interest therein, if any.

SEC source: 0000950170-25-017029 · ownership.xml · derivative · entry 4

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · By Atlas Venture Fund XI, L.P.

Disclosed balance after: 0

Underlying: Common Stock · 719,355 shares

Expires not disclosed

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

F1 · derivative.exercise_price: Each share of Series Seed convertible preferred stock, Series A convertible preferred stock, Series B convertible preferred stock and Series C convertible preferred stock (collectively, the "Preferred Stock") automatically converted into shares of the Issuer's Common Stock on a one-for-1.4611 basis upon the closing of the Issuer's initial public offering on February 10, 2025. The Preferred Stock had no expiration date.

F1 · derivative.exercise_date: Each share of Series Seed convertible preferred stock, Series A convertible preferred stock, Series B convertible preferred stock and Series C convertible preferred stock (collectively, the "Preferred Stock") automatically converted into shares of the Issuer's Common Stock on a one-for-1.4611 basis upon the closing of the Issuer's initial public offering on February 10, 2025. The Preferred Stock had no expiration date.

F1 · derivative.expiration_date: Each share of Series Seed convertible preferred stock, Series A convertible preferred stock, Series B convertible preferred stock and Series C convertible preferred stock (collectively, the "Preferred Stock") automatically converted into shares of the Issuer's Common Stock on a one-for-1.4611 basis upon the closing of the Issuer's initial public offering on February 10, 2025. The Preferred Stock had no expiration date.

F2 · ownership.nature: These shares are held directly by Atlas Venture Fund XI, L.P. ("AVF XI "). The general partner of AVF XI is Atlas Venture Associates XI, L.P. ("AVA XI LP"). Atlas Venture Associates XI, LLC ("AVA XI LLC") is the general partner of AVA XI LP. The Reporting Person is a member of AVA XI LLC and disclaims beneficial ownership of such securities held by AVF XI, except to the extent of his pecuniary interest therein, if any.

SEC source: 0000950170-25-017029 · ownership.xml · nonDerivative · entry 3

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · By Atlas Venture Opportunity Fund II, L.P.

Disclosed balance after: 807,727

F3 · ownership.nature: These shares are held directly by Atlas Venture Opportunity Fund II, L.P. ("AVOF II"). The general partner of AVOF II is Atlas Venture Associates Opportunity II, L.P. ("AVAO II LP"). Atlas Venture Associates Opportunity II, LLC ("AVAO II LLC") is the general partner of AVAO II LP. The Reporting Person is a member of AVAO II LLC and disclaims beneficial ownership of such securities held by AVOF II, except to the extent of his pecuniary interest therein, if any.

SEC source: 0000950170-25-017029 · ownership.xml · nonDerivative · entry 2

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · By Atlas Venture Opportunity Fund II, L.P.

Disclosed balance after: 747,727

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

F1 · price: Each share of Series Seed convertible preferred stock, Series A convertible preferred stock, Series B convertible preferred stock and Series C convertible preferred stock (collectively, the "Preferred Stock") automatically converted into shares of the Issuer's Common Stock on a one-for-1.4611 basis upon the closing of the Issuer's initial public offering on February 10, 2025. The Preferred Stock had no expiration date.

F3 · ownership.nature: These shares are held directly by Atlas Venture Opportunity Fund II, L.P. ("AVOF II"). The general partner of AVOF II is Atlas Venture Associates Opportunity II, L.P. ("AVAO II LP"). Atlas Venture Associates Opportunity II, LLC ("AVAO II LLC") is the general partner of AVAO II LP. The Reporting Person is a member of AVAO II LLC and disclaims beneficial ownership of such securities held by AVOF II, except to the extent of his pecuniary interest therein, if any.

SEC source: 0000950170-25-017029 · ownership.xml · nonDerivative · entry 1

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · By Atlas Venture Fund XI, L.P.

Disclosed balance after: 2,886,293

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

F1 · price: Each share of Series Seed convertible preferred stock, Series A convertible preferred stock, Series B convertible preferred stock and Series C convertible preferred stock (collectively, the "Preferred Stock") automatically converted into shares of the Issuer's Common Stock on a one-for-1.4611 basis upon the closing of the Issuer's initial public offering on February 10, 2025. The Preferred Stock had no expiration date.

F2 · ownership.nature: These shares are held directly by Atlas Venture Fund XI, L.P. ("AVF XI "). The general partner of AVF XI is Atlas Venture Associates XI, L.P. ("AVA XI LP"). Atlas Venture Associates XI, LLC ("AVA XI LLC") is the general partner of AVA XI LP. The Reporting Person is a member of AVA XI LLC and disclaims beneficial ownership of such securities held by AVF XI, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001415889-24-019440 · form4-07092024_090724.xml · nonDerivative · entry 10

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 723,246

F8 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Opportunity Fund I, L.P. on January 22, 2024.

F7 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $38.97 to $39.85 inclusive.

F9 · ownership.nature: The shares are owned directly by Atlas Venture Opportunity Fund I, L.P. ("AVOF I"). Atlas Venture Associates Opportunity I, L.P. ("AVAO LP") is the general partner of AVOF I. Atlas Venture Associates Opportunity I, LLC ("AVAO LLC") is the general partner of AVAO LP. The Reporting Person is a member of AVAO LLC and disclaims Section 16 beneficial ownership of such securities held by AVOF I, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001415889-24-019440 · form4-07092024_090724.xml · nonDerivative · entry 9

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 743,484

F8 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Opportunity Fund I, L.P. on January 22, 2024.

F6 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $37.97 to $38.96 inclusive.

F9 · ownership.nature: The shares are owned directly by Atlas Venture Opportunity Fund I, L.P. ("AVOF I"). Atlas Venture Associates Opportunity I, L.P. ("AVAO LP") is the general partner of AVOF I. Atlas Venture Associates Opportunity I, LLC ("AVAO LLC") is the general partner of AVAO LP. The Reporting Person is a member of AVAO LLC and disclaims Section 16 beneficial ownership of such securities held by AVOF I, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001415889-24-019440 · form4-07092024_090724.xml · nonDerivative · entry 8

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 782,090

F8 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Opportunity Fund I, L.P. on January 22, 2024.

F5 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $36.97 to $37.96 inclusive.

F9 · ownership.nature: The shares are owned directly by Atlas Venture Opportunity Fund I, L.P. ("AVOF I"). Atlas Venture Associates Opportunity I, L.P. ("AVAO LP") is the general partner of AVOF I. Atlas Venture Associates Opportunity I, LLC ("AVAO LLC") is the general partner of AVAO LP. The Reporting Person is a member of AVAO LLC and disclaims Section 16 beneficial ownership of such securities held by AVOF I, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001415889-24-019440 · form4-07092024_090724.xml · nonDerivative · entry 7

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 790,859

F8 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Opportunity Fund I, L.P. on January 22, 2024.

F4 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $35.96 to $36.91 inclusive.

F9 · ownership.nature: The shares are owned directly by Atlas Venture Opportunity Fund I, L.P. ("AVOF I"). Atlas Venture Associates Opportunity I, L.P. ("AVAO LP") is the general partner of AVOF I. Atlas Venture Associates Opportunity I, LLC ("AVAO LLC") is the general partner of AVAO LP. The Reporting Person is a member of AVAO LLC and disclaims Section 16 beneficial ownership of such securities held by AVOF I, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001415889-24-019440 · form4-07092024_090724.xml · nonDerivative · entry 6

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 796,889

F8 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Opportunity Fund I, L.P. on January 22, 2024.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $34.96 to $35.94 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 each separate price within the ranges set forth in footnotes (2), (4), (5), (6) and (7).

F9 · ownership.nature: The shares are owned directly by Atlas Venture Opportunity Fund I, L.P. ("AVOF I"). Atlas Venture Associates Opportunity I, L.P. ("AVAO LP") is the general partner of AVOF I. Atlas Venture Associates Opportunity I, LLC ("AVAO LLC") is the general partner of AVAO LP. The Reporting Person is a member of AVAO LLC and disclaims Section 16 beneficial ownership of such securities held by AVOF I, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001415889-24-019440 · form4-07092024_090724.xml · nonDerivative · entry 5

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 4,173,216

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. on January 22, 2024.

F7 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $38.97 to $39.85 inclusive.

F3 · ownership.nature: These shares are held directly by Atlas Venture Fund X, L.P. ("Atlas Venture Fund X"). The general partner of Atlas Venture Fund X is Atlas Venture Associates X, L.P. ("AVA X LP"). Atlas Venture Associates X, LLC ("AVA X LLC") is the general partner of AVA X LP. The Reporting Person is a member of AVA X LLC and disclaims Section 16 beneficial ownership of the securities held by Atlas Venture Fund X, except to the extend of his pecuniary interest therein, if any.