KYMR

SEC source: 0001451612-26-000016 · form4-06262026_010658.xml · nonDerivative · entry 13

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 543,864

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. on December 11, 2025.

F4 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $120.08 to $121.0794 inclusive.

F14 · ownership.nature: The shares are owned directly by Atlas Venture Opportunity Fund I, L.P. ("AVOF"). Atlas Venture Associates Opportunity I, L.P. ("AVAO LP") is the general partner of AVOF. 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, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001451612-26-000016 · form4-06262026_010658.xml · nonDerivative · entry 12

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 559,524

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. on December 11, 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 $119.08 to $120.0798 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) and (4) through (13).

F14 · ownership.nature: The shares are owned directly by Atlas Venture Opportunity Fund I, L.P. ("AVOF"). Atlas Venture Associates Opportunity I, L.P. ("AVAO LP") is the general partner of AVOF. 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, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001451612-26-000016 · form4-06262026_010658.xml · nonDerivative · entry 11

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 2,862,351

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. on December 11, 2025.

F13 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $129.3041 to $130.05 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 extent of his pecuniary interest therein, if any.

SEC source: 0001451612-26-000016 · form4-06262026_010658.xml · nonDerivative · entry 10

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 2,862,688

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. on December 11, 2025.

F12 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $128.3008 to $129.2819 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 extent of his pecuniary interest therein, if any.

SEC source: 0001451612-26-000016 · form4-06262026_010658.xml · nonDerivative · entry 9

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 2,864,885

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. on December 11, 2025.

F11 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $127.30 to $128.2975 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 extent of his pecuniary interest therein, if any.

SEC source: 0001451612-26-000016 · form4-06262026_010658.xml · nonDerivative · entry 8

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 2,889,960

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. on December 11, 2025.

F10 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $126.13 to $127.0511 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 extent of his pecuniary interest therein, if any.

SEC source: 0001451612-26-000016 · form4-06262026_010658.xml · nonDerivative · entry 7

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 2,891,569

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. on December 11, 2025.

F9 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $125.1194 to $126.115 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 extent of his pecuniary interest therein, if any.

SEC source: 0001451612-26-000016 · form4-06262026_010658.xml · nonDerivative · entry 6

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 2,895,285

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. on December 11, 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 $124.09 to $125.0292 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 extent of his pecuniary interest therein, if any.

SEC source: 0001451612-26-000016 · form4-06262026_010658.xml · nonDerivative · entry 5

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 2,906,996

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. on December 11, 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 $123.09 to $124.08 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 extent of his pecuniary interest therein, if any.

SEC source: 0001451612-26-000016 · form4-06262026_010658.xml · nonDerivative · entry 4

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 2,917,856

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. on December 11, 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 $122.0858 to $123.08 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 extent of his pecuniary interest therein, if any.

SEC source: 0001451612-26-000016 · form4-06262026_010658.xml · nonDerivative · entry 3

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 2,922,833

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. on December 11, 2025.

F5 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $121.08 to $122.0731 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 extent of his pecuniary interest therein, if any.

SEC source: 0001451612-26-000016 · form4-06262026_010658.xml · nonDerivative · entry 2

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 2,963,607

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. on December 11, 2025.

F4 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $120.08 to $121.0794 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 extent of his pecuniary interest therein, if any.

SEC source: 0001451612-26-000016 · form4-06262026_010658.xml · nonDerivative · entry 1

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 3,075,906

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. on December 11, 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 $119.08 to $120.0798 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) and (4) through (13).

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 extent of his pecuniary interest therein, if any.

SEC source: 0001451612-26-000015 · form4-06262026_010604.xml · nonDerivative · entry 30

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 564,668

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. on December 11, 2025.

F18 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $118.0793 to 119.0789 inclusive.

F4 · ownership.nature: The shares are owned directly by Atlas Venture Opportunity Fund I, L.P. ("AVOF"). Atlas Venture Associates Opportunity I, L.P. ("AVAO LP") is the general partner of AVOF. 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, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001451612-26-000015 · form4-06262026_010604.xml · nonDerivative · entry 29

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 567,314

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. on December 11, 2025.

F17 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $117.0787 to $118.0736 inclusive.

F4 · ownership.nature: The shares are owned directly by Atlas Venture Opportunity Fund I, L.P. ("AVOF"). Atlas Venture Associates Opportunity I, L.P. ("AVAO LP") is the general partner of AVOF. 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, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001451612-26-000015 · form4-06262026_010604.xml · nonDerivative · entry 28

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 570,673

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. on December 11, 2025.

F16 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $116.0783 to $117.0773 inclusive.

F4 · ownership.nature: The shares are owned directly by Atlas Venture Opportunity Fund I, L.P. ("AVOF"). Atlas Venture Associates Opportunity I, L.P. ("AVAO LP") is the general partner of AVOF. 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, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001451612-26-000015 · form4-06262026_010604.xml · nonDerivative · entry 27

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 582,048

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. on December 11, 2025.

F15 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $115.0739 to $116.0726 inclusive.

F4 · ownership.nature: The shares are owned directly by Atlas Venture Opportunity Fund I, L.P. ("AVOF"). Atlas Venture Associates Opportunity I, L.P. ("AVAO LP") is the general partner of AVOF. 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, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001451612-26-000015 · form4-06262026_010604.xml · nonDerivative · entry 26

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 590,437

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. on December 11, 2025.

F14 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $114.0602 to $115.0549 inclusive.

F4 · ownership.nature: The shares are owned directly by Atlas Venture Opportunity Fund I, L.P. ("AVOF"). Atlas Venture Associates Opportunity I, L.P. ("AVAO LP") is the general partner of AVOF. 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, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001451612-26-000015 · form4-06262026_010604.xml · nonDerivative · entry 25

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 591,726

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. on December 11, 2025.

F13 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $113.0556 to $114.0429 inclusive.

F4 · ownership.nature: The shares are owned directly by Atlas Venture Opportunity Fund I, L.P. ("AVOF"). Atlas Venture Associates Opportunity I, L.P. ("AVAO LP") is the general partner of AVOF. 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, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001451612-26-000015 · form4-06262026_010604.xml · nonDerivative · entry 24

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 593,163

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. on December 11, 2025.

F12 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $111.82 to $111.96 inclusive.

F4 · ownership.nature: The shares are owned directly by Atlas Venture Opportunity Fund I, L.P. ("AVOF"). Atlas Venture Associates Opportunity I, L.P. ("AVAO LP") is the general partner of AVOF. 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, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001451612-26-000015 · form4-06262026_010604.xml · nonDerivative · entry 23

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 593,263

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. on December 11, 2025.

F11 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $110.72 to $110.96 inclusive.

F4 · ownership.nature: The shares are owned directly by Atlas Venture Opportunity Fund I, L.P. ("AVOF"). Atlas Venture Associates Opportunity I, L.P. ("AVAO LP") is the general partner of AVOF. 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, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001451612-26-000015 · form4-06262026_010604.xml · nonDerivative · entry 22

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 593,349

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. on December 11, 2025.

F10 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $109.66 to $110.57 inclusive.

F4 · ownership.nature: The shares are owned directly by Atlas Venture Opportunity Fund I, L.P. ("AVOF"). Atlas Venture Associates Opportunity I, L.P. ("AVAO LP") is the general partner of AVOF. 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, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001451612-26-000015 · form4-06262026_010604.xml · nonDerivative · entry 21

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 593,614

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. on December 11, 2025.

F9 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $108.5492 to $109.4604 inclusive.

F4 · ownership.nature: The shares are owned directly by Atlas Venture Opportunity Fund I, L.P. ("AVOF"). Atlas Venture Associates Opportunity I, L.P. ("AVAO LP") is the general partner of AVOF. 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, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001451612-26-000015 · form4-06262026_010604.xml · nonDerivative · entry 20

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 595,625

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. on December 11, 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 $107.4762 to $108.3781 inclusive.

F4 · ownership.nature: The shares are owned directly by Atlas Venture Opportunity Fund I, L.P. ("AVOF"). Atlas Venture Associates Opportunity I, L.P. ("AVAO LP") is the general partner of AVOF. 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, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001451612-26-000015 · form4-06262026_010604.xml · nonDerivative · entry 19

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 595,648

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. on December 11, 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 $106.40 to $107.3612 inclusive.

F4 · ownership.nature: The shares are owned directly by Atlas Venture Opportunity Fund I, L.P. ("AVOF"). Atlas Venture Associates Opportunity I, L.P. ("AVAO LP") is the general partner of AVOF. 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, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001451612-26-000015 · form4-06262026_010604.xml · nonDerivative · entry 18

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 3,113,085

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. on December 11, 2025.

F18 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $118.0793 to 119.0789 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 extent of his pecuniary interest therein, if any.

SEC source: 0001451612-26-000015 · form4-06262026_010604.xml · nonDerivative · entry 17

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 3,132,174

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. on December 11, 2025.

F17 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $117.0787 to $118.0736 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 extent of his pecuniary interest therein, if any.

SEC source: 0001451612-26-000015 · form4-06262026_010604.xml · nonDerivative · entry 16

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 3,156,442

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. on December 11, 2025.

F16 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $116.0783 to $117.0773 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 extent of his pecuniary interest therein, if any.

SEC source: 0001451612-26-000015 · form4-06262026_010604.xml · nonDerivative · entry 15

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 3,237,942

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. on December 11, 2025.

F15 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $115.0739 to $116.0726 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 extent of his pecuniary interest therein, if any.

SEC source: 0001451612-26-000015 · form4-06262026_010604.xml · nonDerivative · entry 14

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 3,296,147

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. on December 11, 2025.

F14 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $114.0602 to $115.0549 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 extent of his pecuniary interest therein, if any.

SEC source: 0001451612-26-000015 · form4-06262026_010604.xml · nonDerivative · entry 13

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 3,305,376

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. on December 11, 2025.

F13 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $113.0556 to $114.0429 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 extent of his pecuniary interest therein, if any.

SEC source: 0001451612-26-000015 · form4-06262026_010604.xml · nonDerivative · entry 12

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 3,315,591

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. on December 11, 2025.

F12 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $111.82 to $111.96 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 extent of his pecuniary interest therein, if any.

SEC source: 0001451612-26-000015 · form4-06262026_010604.xml · nonDerivative · entry 11

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 3,316,310

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. on December 11, 2025.

F11 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $110.72 to $110.96 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 extent of his pecuniary interest therein, if any.

SEC source: 0001451612-26-000015 · form4-06262026_010604.xml · nonDerivative · entry 10

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 3,316,924

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. on December 11, 2025.

F10 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $109.66 to $110.57 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 extent of his pecuniary interest therein, if any.

SEC source: 0001451612-26-000015 · form4-06262026_010604.xml · nonDerivative · entry 9

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 3,318,839

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. on December 11, 2025.

F9 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $108.5492 to $109.4604 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 extent of his pecuniary interest therein, if any.

SEC source: 0001451612-26-000015 · form4-06262026_010604.xml · nonDerivative · entry 8

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 3,333,190

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. on December 11, 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 $107.4762 to $108.3781 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 extent of his pecuniary interest therein, if any.

SEC source: 0001451612-26-000015 · form4-06262026_010604.xml · nonDerivative · entry 7

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 3,333,349

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. on December 11, 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 $106.40 to $107.3612 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 extent of his pecuniary interest therein, if any.

SEC source: 0001193125-26-283139 · ownership.xml · derivative · entry 4

Goodman Noah · CIK 0002060075 · Chief Business Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 90,000

Underlying: Common Stock · 5,000 shares

Expires 2035-04-07

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 · kind: These transactions were effected pursuant to a Rule 10b5-1 trading plan dated December 10, 2025 adopted by the reporting person.

F2 · derivative.exercise_date: Twenty-five percent (25%) of the shares underlying this stock option vested on April 8, 2026, with the remainder vesting in thirty-six (36) equal monthly installments thereafter, subject to the reporting person's continued employment through each vesting date.

SEC source: 0001193125-26-283139 · ownership.xml · nonDerivative · entry 3

Goodman Noah · CIK 0002060075 · Chief Business Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 50,195.438

F1 · kind: These transactions were effected pursuant to a Rule 10b5-1 trading plan dated December 10, 2025 adopted by the reporting person.

SEC source: 0001193125-26-283139 · ownership.xml · nonDerivative · entry 2

Goodman Noah · CIK 0002060075 · Chief Business Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 52,695.438

F1 · kind: These transactions were effected pursuant to a Rule 10b5-1 trading plan dated December 10, 2025 adopted by the reporting person.

SEC source: 0001193125-26-283139 · ownership.xml · nonDerivative · entry 1

Goodman Noah · CIK 0002060075 · Chief Business Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 55,195.438

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 · kind: These transactions were effected pursuant to a Rule 10b5-1 trading plan dated December 10, 2025 adopted by the reporting person.

SEC source: 0000921895-26-001680 · form407422010_06252026.xml · derivative · entry 5

BVF PARTNERS L P/IL · CIK 0001055947 · Director · See Remarks and Footnotes

BIOTECHNOLOGY VALUE FUND L P · CIK 0000918923 · Director · See Remarks and Footnotes

BVF I GP LLC · CIK 0001803805 · Director · See Remarks and Footnotes

BIOTECHNOLOGY VALUE FUND II LP · CIK 0001102444 · Director · See Remarks and Footnotes

BVF II GP LLC · CIK 0001803806 · Director · See Remarks and Footnotes

Biotechnology Value Trading Fund OS LP · CIK 0001660683 · Director · See Remarks and Footnotes

BVF Partners OS Ltd. · CIK 0001660684 · Director · See Remarks and Footnotes

BVF GP HOLDINGS LLC · CIK 0001803809 · Director · See Remarks and Footnotes

BVF INC/IL · CIK 0001056807 · Director · See Remarks and Footnotes

LAMPERT MARK N · CIK 0001233840 · Director · See Remarks and Footnotes

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

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnote

Disclosed balance after: 6,068

Underlying: Common Stock, $0.0001 par value · 6,068 shares

Expires 2036-06-23

F6 · security: Partners, BVF Inc. and Mr. Lampert may be deemed to have a pecuniary interest in the securities reported owned herein due to a certain agreement between Partners and Gorjan Hrustanovic, who serves on the Issuer's board of directors and as a member of Partners, pursuant to which Mr. Hrustanovic is obligated to transfer the economic benefit, if any, received upon the sale of the shares issuable upon exercise of the securities reported owned herein to Partners. As such, Mr. Hrustanovic disclaims beneficial ownership of the securities reported herein except to the extent of his pecuniary interest therein.

F7 · derivative.exercise_date: The shares underlying this stock option shall vest in full upon the earlier to occur of (i) June 24, 2027 and (ii) the date of the next annual meeting of the Issuer's stockholders.

F6 · ownership.direct: Partners, BVF Inc. and Mr. Lampert may be deemed to have a pecuniary interest in the securities reported owned herein due to a certain agreement between Partners and Gorjan Hrustanovic, who serves on the Issuer's board of directors and as a member of Partners, pursuant to which Mr. Hrustanovic is obligated to transfer the economic benefit, if any, received upon the sale of the shares issuable upon exercise of the securities reported owned herein to Partners. As such, Mr. Hrustanovic disclaims beneficial ownership of the securities reported herein except to the extent of his pecuniary interest therein.

F6 · ownership.nature: Partners, BVF Inc. and Mr. Lampert may be deemed to have a pecuniary interest in the securities reported owned herein due to a certain agreement between Partners and Gorjan Hrustanovic, who serves on the Issuer's board of directors and as a member of Partners, pursuant to which Mr. Hrustanovic is obligated to transfer the economic benefit, if any, received upon the sale of the shares issuable upon exercise of the securities reported owned herein to Partners. As such, Mr. Hrustanovic disclaims beneficial ownership of the securities reported herein except to the extent of his pecuniary interest therein.

SEC source: 0001193125-26-283039 · ownership.xml · derivative · entry 2

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director · 10% owner

667, L.P. · CIK 0001551139 · Director · 10% owner

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director · 10% owner

Baker Brothers Life Sciences LP · CIK 0001363364 · Director · 10% owner

BAKER FELIX · CIK 0001087940 · Director · 10% owner

BAKER JULIAN · CIK 0001087939 · Director · 10% owner

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

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 6,068

Underlying: Common Stock · 6,068 shares

Expires 2036-06-23

F1 · shares: 6,068 non-qualified stock options ("Stock Options") exercisable solely into common stock ("Common Stock") of Kymera Therapeutics, Inc. (the "Issuer") were granted under the Issuer's 2020 Stock Option and Incentive Plan to Felix J. Baker, a managing member of Baker Bros. Advisors (GP) LLC (the "Adviser GP") in his capacity as a director of the Issuer. The Stock Options have a strike price of $99.87 per share, and vest on the earlier of the first anniversary of the grant date or the date of the next annual meeting of stockholders of the Issuer, subject to Felix J. Baker's continued service on the board of directors of the Issuer (the "Board") through such vesting date and expire on June 23, 2036. Felix J. Baker serves on the Board as a representative of Baker Brothers Life Sciences, L.P. ("Life Sciences") and 667, L.P. ("667", and together with Life Sciences, the "Funds").

F1 · derivative.exercise_date: 6,068 non-qualified stock options ("Stock Options") exercisable solely into common stock ("Common Stock") of Kymera Therapeutics, Inc. (the "Issuer") were granted under the Issuer's 2020 Stock Option and Incentive Plan to Felix J. Baker, a managing member of Baker Bros. Advisors (GP) LLC (the "Adviser GP") in his capacity as a director of the Issuer. The Stock Options have a strike price of $99.87 per share, and vest on the earlier of the first anniversary of the grant date or the date of the next annual meeting of stockholders of the Issuer, subject to Felix J. Baker's continued service on the board of directors of the Issuer (the "Board") through such vesting date and expire on June 23, 2036. Felix J. Baker serves on the Board as a representative of Baker Brothers Life Sciences, L.P. ("Life Sciences") and 667, L.P. ("667", and together with Life Sciences, the "Funds").

F2 · ownership.nature: Pursuant to the policies of Baker Bros. Advisors LP (the "Adviser"), Felix J. Baker does not have any right to any of the Issuer's securities issued as part of his service on the Board and the Funds are entitled to receive all the pecuniary interest in the securities issued. The Funds each own an indirect proportionate pecuniary interest in the Stock Options. Solely as a result of Felix J. Baker's and Julian C. Baker's ownership interests in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the Stock Options and any Common Stock acquired upon the exercise of Stock Options (i.e. no direct pecuniary interest) issued as compensation for such Board service. Pursuant to the policies of the Adviser, the Adviser has voting and dispositive power over the Stock Options and any Common Stock acquired as a result of the exercise of the Stock Options.

F3 · ownership.nature: The Adviser serves as the investment adviser to the Funds. In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held for the benefit of the Funds. The Adviser GP is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held for the benefit of the Funds.

F4 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F6 · ownership.nature: The acquisition of Stock Options reported on this form represents a single grant to Felix J. Baker of 6,068 Stock Options on Table II. This grant of 6,068 Stock Options to Felix J. Baker is reported for each of the Funds as each has an indirect pecuniary interest in such securities.

F7 · ownership.nature: After giving effect to the transaction reported herein and as a result of their ownership interest in (i) Baker Brothers Life Sciences Capital, L.P. and (ii) Life Sciences, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in the Stock Options reported in column 9 of Table II held for the benefit of Life Sciences, a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital, L.P., a limited partnership of which the sole general partner is Baker Brothers Life Sciences Capital (GP), LLC, due to their interest in Life Sciences and Baker Brothers Life Sciences Capital, L.P.'s right to receive an allocation of a portion of the profits from Life Sciences.

SEC source: 0001193125-26-283039 · ownership.xml · derivative · entry 1

BAKER BROS. ADVISORS LP · CIK 0001263508 · Director · 10% owner

667, L.P. · CIK 0001551139 · Director · 10% owner

Baker Bros. Advisors (GP) LLC · CIK 0001580575 · Director · 10% owner

Baker Brothers Life Sciences LP · CIK 0001363364 · Director · 10% owner

BAKER FELIX · CIK 0001087940 · Director · 10% owner

BAKER JULIAN · CIK 0001087939 · Director · 10% owner

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

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 6,068

Underlying: Common Stock · 6,068 shares

Expires 2036-06-23

F1 · shares: 6,068 non-qualified stock options ("Stock Options") exercisable solely into common stock ("Common Stock") of Kymera Therapeutics, Inc. (the "Issuer") were granted under the Issuer's 2020 Stock Option and Incentive Plan to Felix J. Baker, a managing member of Baker Bros. Advisors (GP) LLC (the "Adviser GP") in his capacity as a director of the Issuer. The Stock Options have a strike price of $99.87 per share, and vest on the earlier of the first anniversary of the grant date or the date of the next annual meeting of stockholders of the Issuer, subject to Felix J. Baker's continued service on the board of directors of the Issuer (the "Board") through such vesting date and expire on June 23, 2036. Felix J. Baker serves on the Board as a representative of Baker Brothers Life Sciences, L.P. ("Life Sciences") and 667, L.P. ("667", and together with Life Sciences, the "Funds").

F1 · derivative.exercise_date: 6,068 non-qualified stock options ("Stock Options") exercisable solely into common stock ("Common Stock") of Kymera Therapeutics, Inc. (the "Issuer") were granted under the Issuer's 2020 Stock Option and Incentive Plan to Felix J. Baker, a managing member of Baker Bros. Advisors (GP) LLC (the "Adviser GP") in his capacity as a director of the Issuer. The Stock Options have a strike price of $99.87 per share, and vest on the earlier of the first anniversary of the grant date or the date of the next annual meeting of stockholders of the Issuer, subject to Felix J. Baker's continued service on the board of directors of the Issuer (the "Board") through such vesting date and expire on June 23, 2036. Felix J. Baker serves on the Board as a representative of Baker Brothers Life Sciences, L.P. ("Life Sciences") and 667, L.P. ("667", and together with Life Sciences, the "Funds").

F2 · ownership.nature: Pursuant to the policies of Baker Bros. Advisors LP (the "Adviser"), Felix J. Baker does not have any right to any of the Issuer's securities issued as part of his service on the Board and the Funds are entitled to receive all the pecuniary interest in the securities issued. The Funds each own an indirect proportionate pecuniary interest in the Stock Options. Solely as a result of Felix J. Baker's and Julian C. Baker's ownership interests in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the Stock Options and any Common Stock acquired upon the exercise of Stock Options (i.e. no direct pecuniary interest) issued as compensation for such Board service. Pursuant to the policies of the Adviser, the Adviser has voting and dispositive power over the Stock Options and any Common Stock acquired as a result of the exercise of the Stock Options.

F3 · ownership.nature: The Adviser serves as the investment adviser to the Funds. In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held for the benefit of the Funds. The Adviser GP is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held for the benefit of the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held for the benefit of the Funds.

F4 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held for the benefit of the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

F5 · ownership.nature: After giving effect to the transaction reported herein and as a result of their ownership interest in (i) Baker Biotech Capital, L.P. and (ii) 667, Julian C. Baker and Felix J. Baker each may be deemed to have an indirect pecuniary interest in the Stock Options reported in column 9 of Table II held for the benefit of 667, a limited partnership of which the sole general partner is Baker Biotech Capital, L.P., a limited partnership of which the sole general partner is Baker Biotech Capital (GP), LLC, due to their interest in 667 and Baker Biotech Capital, L.P.'s right to receive an allocation of a portion of the profits from 667.

F6 · ownership.nature: The acquisition of Stock Options reported on this form represents a single grant to Felix J. Baker of 6,068 Stock Options on Table II. This grant of 6,068 Stock Options to Felix J. Baker is reported for each of the Funds as each has an indirect pecuniary interest in such securities.

SEC source: 0001193125-26-283137 · ownership.xml · derivative · entry 1

MARAGANORE JOHN · CIK 0001180432 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 6,068

Underlying: Common Stock · 6,068 shares

Expires 2036-06-23

F1 · derivative.exercise_date: The shares underlying this stock option shall vest in full upon the earlier to occur of (i) June 24, 2027 and (ii) the date of the next annual meeting of the Issuer's stockholders.

SEC source: 0001451612-26-000015 · form4-06262026_010604.xml · nonDerivative · entry 6

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 597,047

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. on December 11, 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 $100.95 to $101.5246 inclusive.

F4 · ownership.nature: The shares are owned directly by Atlas Venture Opportunity Fund I, L.P. ("AVOF"). Atlas Venture Associates Opportunity I, L.P. ("AVAO LP") is the general partner of AVOF. 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, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001451612-26-000015 · form4-06262026_010604.xml · nonDerivative · entry 5

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 3,343,343

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. on December 11, 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 $100.95 to $101.5246 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 extent of his pecuniary interest therein, if any.

SEC source: 0001451612-26-000015 · form4-06262026_010604.xml · nonDerivative · entry 4

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 599,076

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. on December 11, 2025.

F5 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $99.95 to $100.9487 inclusive.

F4 · ownership.nature: The shares are owned directly by Atlas Venture Opportunity Fund I, L.P. ("AVOF"). Atlas Venture Associates Opportunity I, L.P. ("AVAO LP") is the general partner of AVOF. 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, except to the extent of his pecuniary interest therein, if any.

SEC source: 0001451612-26-000015 · form4-06262026_010604.xml · nonDerivative · entry 3

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: Plan reported

Ownership: Indirect · See footnote

Disclosed balance after: 3,357,833

F1 · kind: This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. on December 11, 2025.

F5 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $99.95 to $100.9487 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 extent of his pecuniary interest therein, if any.

SEC source: 0001193125-26-283141 · ownership.xml · derivative · entry 1

Booth Bruce · CIK 0001451612 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 6,068

Underlying: Common Stock · 6,068 shares

Expires 2036-06-23

F1 · derivative.exercise_date: The shares underlying this stock option shall vest in full upon the earlier to occur of (i) June 24, 2027 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.