PRLD

SEC source: 0001562180-25-000955 · primarydocument.xml · derivative · entry 1

Vaddi Krishna · CIK 0001824633 · Director · CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 496,000

Underlying: Common Stock · 496,000 shares

Expires 2035-02-04

F1 · derivative.exercise_date: The stock option vests as to 25% of the total shares on Feb 4, 2026, and thereafter vests as to 1/48 of the total shares monthly until fully vested, subject to the Reporting Person's provision of service to the Issuer on each vesting date.

SEC source: 0001562180-25-000237 · primarydocument.xml · derivative · entry 3

Huang Jane · CIK 0001683913 · President, CMO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 46,875

Underlying: Common Stock · 9,375 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 Restricted Stock Unit ("RSU") represents a contingent right to receive one share of Issuer's Common Stock.

F3 · derivative.exercise_date: The RSUs were granted on May 2, 2022 and vest according to the reporting person's employment agreement. The RSUs vested as to 1/4 of the total shares on April 4, 2023, and 1/16 of the remaining shares shall vest quarterly thereafter until fully vested, subject to the continued service of the Reporting Person to the Issuer through each vesting date.

F3 · derivative.expiration_date: The RSUs were granted on May 2, 2022 and vest according to the reporting person's employment agreement. The RSUs vested as to 1/4 of the total shares on April 4, 2023, and 1/16 of the remaining shares shall vest quarterly thereafter until fully vested, subject to the continued service of the Reporting Person to the Issuer through each vesting date.

SEC source: 0001562180-25-000237 · primarydocument.xml · nonDerivative · entry 2

Huang Jane · CIK 0001683913 · President, CMO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 68,857

F2 · shares: Represents shares withheld by the Issuer to satisfy the tax withholding obligation in connection with the vesting of RSUs.

SEC source: 0001562180-25-000237 · primarydocument.xml · nonDerivative · entry 1

Huang Jane · CIK 0001683913 · President, CMO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 72,716

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 Restricted Stock Unit ("RSU") represents a contingent right to receive one share of Issuer's Common Stock.

SEC source: 0001562180-25-000031 · primarydocument.xml · nonDerivative · entry 1

Vaddi Krishna · CIK 0001824633 · Director · CEO

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnote

Disclosed balance after: 142,553

F1 · ownership.nature: The Reporting Person is the manager of Sidus Ventures LLC. The Reporting Person disclaims beneficial ownership of such securities except to the extent of his pecuniary interest therein, and the inclusion of these securities in this report shall not be deemed an admission of beneficial ownership of such securities for purposes of Section 16 or for any other purposes.

SEC source: 0001562180-25-000008 · primarydocument.xml · nonDerivative · entry 1

Vaddi Krishna · CIK 0001824633 · Director · CEO

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnote

Disclosed balance after: 137,553

F1 · ownership.nature: The Reporting Person is the manager of Sidus Ventures LLC. The Reporting Person disclaims beneficial ownership of such securities except to the extent of his pecuniary interest therein, and the inclusion of these securities in this report shall not be deemed an admission of beneficial ownership of such securities for purposes of Section 16 or for any other purposes.

SEC source: 0001562180-24-008565 · primarydocument.xml · nonDerivative · entry 2

Combs Andrew · CIK 0001825005 · Chief Chemistry Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 377,623

F2 · price: The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $1.20 to $1.55, 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 purchased at each separate price within the ranges set forth herein.

SEC source: 0001562180-24-008565 · primarydocument.xml · nonDerivative · entry 1

Combs Andrew · CIK 0001825005 · Chief Chemistry Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 317,623

F1 · balance_after: The reported total includes 10,106 shares of common stock the reporting person has acquired since the date of his last ownership report through the issuer's Employee Stock Purchase Plan in one or more transactions exempt pursuant to Rules 16b-3(c).

SEC source: 0001562180-24-008532 · primarydocument.xml · nonDerivative · entry 1

Lim Bryant David · CIK 0001752888 · CLO, Interim CFO, Corp Sec.

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 27,400

F1 · price: 1. The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $0.87 to $0.96, 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 purchased at each separate price within the ranges set forth herein.

SEC source: 0001562180-24-008531 · primarydocument.xml · nonDerivative · entry 2

Vaddi Krishna · CIK 0001824633 · Director · CEO

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnote

Disclosed balance after: 127,553

F2 · ownership.nature: The Reporting Person is the manager of Sidus Ventures LLC. The Reporting Person disclaims beneficial ownership of such securities except to the extent of his pecuniary interest therein, and the inclusion of these securities in this report shall not be deemed an admission of beneficial ownership of such securities for purposes of Section 16 or for any other purposes.

SEC source: 0001562180-24-008531 · primarydocument.xml · nonDerivative · entry 1

Vaddi Krishna · CIK 0001824633 · Director · CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,167,275

F1 · price: 1. The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $0.89 to $1.00, 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 purchased at each separate price within the ranges set forth herein.

SEC source: 0001562180-24-007253 · primarydocument.xml · derivative · entry 3

Huang Jane · CIK 0001683913 · President, CMO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 56,250

Underlying: Common Stock · 9,375 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 Restricted Stock Unit ("RSU") represents a contingent right to receive one share of Issuer's Common Stock.

F3 · derivative.exercise_date: The RSUs were granted on May 2, 2022 and vest according to the reporting person's employment agreement. The RSUs vested as to 1/4 of the total shares on April 4, 2023, and 1/16 of the remaining shares shall vest quarterly thereafter until fully vested, subject to the continued service of the Reporting Person to the Issuer through each vesting date.

F3 · derivative.expiration_date: The RSUs were granted on May 2, 2022 and vest according to the reporting person's employment agreement. The RSUs vested as to 1/4 of the total shares on April 4, 2023, and 1/16 of the remaining shares shall vest quarterly thereafter until fully vested, subject to the continued service of the Reporting Person to the Issuer through each vesting date.

SEC source: 0001562180-24-007253 · primarydocument.xml · nonDerivative · entry 2

Huang Jane · CIK 0001683913 · President, CMO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 63,341

F2 · shares: Represents shares withheld by the Issuer to satisfy the tax withholding obligation in connection with the vesting of RSUs.

SEC source: 0001562180-24-007253 · primarydocument.xml · nonDerivative · entry 1

Huang Jane · CIK 0001683913 · President, CMO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 66,690

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 Restricted Stock Unit ("RSU") represents a contingent right to receive one share of Issuer's Common Stock.

SEC source: 0001562180-24-005641 · primarydocument.xml · derivative · entry 3

Huang Jane · CIK 0001683913 · President, CMO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 65,625

Underlying: Common Stock · 9,375 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 Restricted Stock Unit ("RSU") represents a contingent right to receive one share of Issuer's Common Stock.

F3 · derivative.exercise_date: The RSUs were granted on May 2, 2022 and vest according to the reporting person's employment agreement. The RSUs vested as to 1/4 of the total shares on April 4, 2023, and 1/16 of the remaining shares shall vest quarterly thereafter until fully vested, subject to the continued service of the Reporting Person to the Issuer through each vesting date

F3 · derivative.expiration_date: The RSUs were granted on May 2, 2022 and vest according to the reporting person's employment agreement. The RSUs vested as to 1/4 of the total shares on April 4, 2023, and 1/16 of the remaining shares shall vest quarterly thereafter until fully vested, subject to the continued service of the Reporting Person to the Issuer through each vesting date

SEC source: 0001562180-24-005641 · primarydocument.xml · nonDerivative · entry 2

Huang Jane · CIK 0001683913 · President, CMO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 57,315

F2 · shares: Represents shares withheld by the Issuer to satisfy the tax withholding obligation in connection with the vesting of RSUs.

SEC source: 0001562180-24-005641 · primarydocument.xml · nonDerivative · entry 1

Huang Jane · CIK 0001683913 · President, CMO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 60,662

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 Restricted Stock Unit ("RSU") represents a contingent right to receive one share of Issuer's Common Stock.

SEC source: 0000950170-24-074907 · 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: 23,500

Underlying: Common Stock · 23,500 shares

Expires 2034-06-13

F1 · shares: Includes 23,500 non-qualified stock options ("Stock Options") exercisable solely into common stock ("Common Stock") of Prelude Therapeutics Incorporated (the "Issuer") granted by the Issuer to Julian C. Baker, a managing member of Baker Bros. Advisors (GP) LLC (the "Adviser GP"), on June 14, 2024, in his capacity as a director of the Issuer, pursuant to the Issuer's 2020 Stock Incentive Plan, as Amended and Restated (the "Incentive Plan"). The Stock Options have a strike price of $3.90 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 Julian C. Baker's continued service on the board of directors of the Issuer (the "Board") through the vesting date or an earlier change in control of the Issuer. The Stock Options expire on June 13, 2034.

F1 · derivative.exercise_date: Includes 23,500 non-qualified stock options ("Stock Options") exercisable solely into common stock ("Common Stock") of Prelude Therapeutics Incorporated (the "Issuer") granted by the Issuer to Julian C. Baker, a managing member of Baker Bros. Advisors (GP) LLC (the "Adviser GP"), on June 14, 2024, in his capacity as a director of the Issuer, pursuant to the Issuer's 2020 Stock Incentive Plan, as Amended and Restated (the "Incentive Plan"). The Stock Options have a strike price of $3.90 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 Julian C. Baker's continued service on the board of directors of the Issuer (the "Board") through the vesting date or an earlier change in control of the Issuer. The Stock Options expire on June 13, 2034.

F2 · ownership.nature: Julian C. Baker serves on the Board as a representative of 667, L.P. ("667") and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds") and their affiliates and control persons.

F4 · ownership.nature: Baker Bros. Advisors LP (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.

F5 · 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: Pursuant to the policies of the Adviser, Julian C. Baker does not have a right to any of the Issuer's securities issued as compensation for his service on the Board and the Funds are entitled to an indirect proportionate pecuniary interest in such securities. The Funds each own an indirect proportionate pecuniary interest in such securities. Solely as a result of their ownership interest 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 shares of Common Stock, Stock Options and Common Stock issued upon exercise of Stock Options (i.e. no direct pecuniary interest) issued as compensation for such Board service.

F7 · ownership.nature: Pursuant to the policies of the Adviser, the Adviser has voting and dispositive power over the Stock Options and any Common Stock received as a result of the exercise of Stock Options.

F8 · ownership.nature: The acquisition of Stock Options reported on this form represents a single grant to Julian C. Baker of 23,500 Stock Options on Table II. This grant of 23,500 Stock Options for Julian C. Baker is reported for each of the Funds as each has an indirect pecuniary interest in such securities.

F9 · 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: 0000950170-24-074907 · 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: 23,500

Underlying: Common Stock · 23,500 shares

Expires 2034-06-13

F1 · shares: Includes 23,500 non-qualified stock options ("Stock Options") exercisable solely into common stock ("Common Stock") of Prelude Therapeutics Incorporated (the "Issuer") granted by the Issuer to Julian C. Baker, a managing member of Baker Bros. Advisors (GP) LLC (the "Adviser GP"), on June 14, 2024, in his capacity as a director of the Issuer, pursuant to the Issuer's 2020 Stock Incentive Plan, as Amended and Restated (the "Incentive Plan"). The Stock Options have a strike price of $3.90 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 Julian C. Baker's continued service on the board of directors of the Issuer (the "Board") through the vesting date or an earlier change in control of the Issuer. The Stock Options expire on June 13, 2034.

F1 · derivative.exercise_date: Includes 23,500 non-qualified stock options ("Stock Options") exercisable solely into common stock ("Common Stock") of Prelude Therapeutics Incorporated (the "Issuer") granted by the Issuer to Julian C. Baker, a managing member of Baker Bros. Advisors (GP) LLC (the "Adviser GP"), on June 14, 2024, in his capacity as a director of the Issuer, pursuant to the Issuer's 2020 Stock Incentive Plan, as Amended and Restated (the "Incentive Plan"). The Stock Options have a strike price of $3.90 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 Julian C. Baker's continued service on the board of directors of the Issuer (the "Board") through the vesting date or an earlier change in control of the Issuer. The Stock Options expire on June 13, 2034.

F2 · ownership.nature: Julian C. Baker serves on the Board as a representative of 667, L.P. ("667") and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds") and their affiliates and control persons.

F3 · 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.

F4 · ownership.nature: Baker Bros. Advisors LP (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.

F5 · 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: Pursuant to the policies of the Adviser, Julian C. Baker does not have a right to any of the Issuer's securities issued as compensation for his service on the Board and the Funds are entitled to an indirect proportionate pecuniary interest in such securities. The Funds each own an indirect proportionate pecuniary interest in such securities. Solely as a result of their ownership interest 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 shares of Common Stock, Stock Options and Common Stock issued upon exercise of Stock Options (i.e. no direct pecuniary interest) issued as compensation for such Board service.

F7 · ownership.nature: Pursuant to the policies of the Adviser, the Adviser has voting and dispositive power over the Stock Options and any Common Stock received as a result of the exercise of Stock Options.

F8 · ownership.nature: The acquisition of Stock Options reported on this form represents a single grant to Julian C. Baker of 23,500 Stock Options on Table II. This grant of 23,500 Stock Options for Julian C. Baker is reported for each of the Funds as each has an indirect pecuniary interest in such securities.

SEC source: 0001562180-24-005160 · primarydocument.xml · derivative · entry 1

Bonita David P · CIK 0001572451 · Director · 10% owner

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 23,500

Underlying: Common Stock · 23,500 shares

Expires 2034-06-13

F1 · derivative.exercise_date: The option award will fully vest upon the earlier of (a) the Issuer's next annual stockholder meeting, or (b) the one-year anniversary of the grant date, subject to the Reporting Person's provision of service to the Issuer on each vesting date.

F2 · ownership.direct: Pursuant to an agreement with OrbiMed Advisors LLC and OrbiMed Capital GP VI LLC, the Reporting Person is obligated to transfer any securities issued under any such stock options or other awards, or the economic benefit thereof, to OrbiMed Advisors LLC and OrbiMed Capital GP VI LLC, which will in turn ensure that such securities or economic benefits are provided to OrbiMed Private Investments VI, LP.

SEC source: 0001562180-24-005159 · primarydocument.xml · derivative · entry 1

Babler Martin · CIK 0001435618 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 23,500

Underlying: Common Stock · 23,500 shares

Expires 2034-06-13

F1 · derivative.exercise_date: The option award will fully vest upon the earlier of (a) the Issuer's next annual stockholder meeting, or (b) the one-year anniversary of the grant date, subject to the Reporting Person's provision of service to the Issuer on each vesting date.

SEC source: 0001562180-24-005162 · primarydocument.xml · derivative · entry 1

FRIEDMAN PAUL A · CIK 0001236927 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 23,500

Underlying: Common Stock · 23,500 shares

Expires 2034-06-13

F1 · derivative.exercise_date: The option award will fully vest upon the earlier of (a) the Issuer's next annual stockholder meeting, or (b) the one-year anniversary of the grant date, subject to the Reporting Person's provision of service to the Issuer on each vesting date.

SEC source: 0001562180-24-005161 · primarydocument.xml · derivative · entry 1

Dier Mardi · CIK 0001574591 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 23,500

Underlying: Common Stock · 23,500 shares

Expires 2034-06-13

F1 · derivative.exercise_date: The option award will fully vest upon the earlier of (a) the Issuer's next annual stockholder meeting, or (b) the one-year anniversary of the grant date, subject to the Reporting Person's provision of service to the Issuer on each vesting date.

SEC source: 0001562180-24-005163 · primarydocument.xml · derivative · entry 1

Sandor Victor · CIK 0001620368 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 23,500

Underlying: Common Stock · 23,500 shares

Expires 2034-06-13

F1 · derivative.exercise_date: The option award will fully vest upon the earlier of (a) the Issuer's next annual stockholder meeting, or (b) the one-year anniversary of the grant date, subject to the Reporting Person's provision of service to the Issuer on each vesting date.

SEC source: 0001562180-24-004084 · primarydocument.xml · derivative · entry 1

Lim Bryant David · CIK 0001752888 · CLO, Interim CFO, Corp Sec.

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 25,000

Underlying: Common Stock · 25,000 shares

Expires 2034-05-13

F1 · derivative.exercise_date: The stock option vests as to 25% of the total shares on May 14, 2025, and thereafter vests as to 1/48 of the total shares monthly until fully vested, subject to the Reporting Person's provision of service to the Issuer on each vesting date.

SEC source: 0001562180-24-003347 · primarydocument.xml · derivative · entry 3

Huang Jane · CIK 0001683913 · President, CMO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 75,000

Underlying: Common Stock · 9,375 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 Restricted Stock Unit ("RSU") represents a contingent right to receive one share of Issuer's Common Stock.

F3 · derivative.exercise_date: The RSUs were granted on May 2, 2022 and vest according to the reporting person's employment agreement. The RSUs vested as to 1/4 of the total shares on April 4, 2023, and 1/16 of the remaining shares shall vest quarterly thereafter until fully vested, subject to the continued service of the Reporting Person to the Issuer through each vesting date

F3 · derivative.expiration_date: The RSUs were granted on May 2, 2022 and vest according to the reporting person's employment agreement. The RSUs vested as to 1/4 of the total shares on April 4, 2023, and 1/16 of the remaining shares shall vest quarterly thereafter until fully vested, subject to the continued service of the Reporting Person to the Issuer through each vesting date

SEC source: 0001562180-24-003347 · primarydocument.xml · nonDerivative · entry 2

Huang Jane · CIK 0001683913 · President, CMO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 51,287

F2 · shares: Represents shares withheld by the Issuer to satisfy the tax withholding obligation in connection with the vesting of RSUs.

SEC source: 0001562180-24-003347 · primarydocument.xml · nonDerivative · entry 1

Huang Jane · CIK 0001683913 · President, CMO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 54,634

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 Restricted Stock Unit ("RSU") represents a contingent right to receive one share of Issuer's Common Stock.

SEC source: 0001562180-24-002130 · primarydocument.xml · derivative · entry 1

Huang Jane · CIK 0001683913 · President, CMO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 175,000

Underlying: Common Stock · 175,000 shares

Expires 2034-02-28

F1 · derivative.exercise_date: The stock option vests as to 25% of the total shares on March 1, 2025, and thereafter vests as to 1/48 of the total shares monthly until fully vested, subject to the Reporting Person's provision of service to the Issuer on each vesting date.

SEC source: 0001562180-24-002135 · primarydocument.xml · derivative · entry 1

Chardonnet Laurent · CIK 0001329010 · Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 150,000

Underlying: Common Stock · 150,000 shares

Expires 2034-02-28

F1 · derivative.exercise_date: The stock option vests as to 25% of the total shares on March 1, 2025, and thereafter vests as to 1/48 of the total shares monthly until fully vested, subject to the Reporting Person's provision of service to the Issuer on each vesting date.

SEC source: 0001562180-24-002139 · primarydocument.xml · derivative · entry 1

Lim Bryant David · CIK 0001752888 · Chief Legal Officer, Corp Sec.

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 150,000

Underlying: Common Stock · 150,000 shares

Expires 2034-02-28

F1 · derivative.exercise_date: The stock option vests as to 25% of the total shares on March 1, 2025, and thereafter vests as to 1/48 of the total shares monthly until fully vested, subject to the Reporting Person's provision of service to the Issuer on each vesting date.

SEC source: 0001562180-24-002137 · primarydocument.xml · derivative · entry 1

Scherle Peggy · CIK 0001824632 · Chief Scientific Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 150,000

Underlying: Common Stock · 150,000 shares

Expires 2034-02-28

F1 · derivative.exercise_date: The stock option vests as to 25% of the total shares on March 1, 2025, and thereafter vests as to 1/48 of the total shares monthly until fully vested, subject to the Reporting Person's provision of service to the Issuer on each vesting date.

SEC source: 0001562180-24-002136 · primarydocument.xml · derivative · entry 1

Combs Andrew · CIK 0001825005 · Chief Chemistry Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 150,000

Underlying: Common Stock · 150,000 shares

Expires 2034-02-28

F1 · derivative.exercise_date: The stock option vests as to 25% of the total shares on March 1, 2025, and thereafter vests as to 1/48 of the total shares monthly until fully vested, subject to the Reporting Person's provision of service to the Issuer on each vesting date.

SEC source: 0001562180-24-002127 · primarydocument.xml · derivative · entry 1

Vaddi Krishna · CIK 0001824633 · Director · CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 425,000

Underlying: Common Stock · 425,000 shares

Expires 2034-02-28

F1 · derivative.exercise_date: The stock option vests as to 25% of the total shares on March 1, 2025, and thereafter vests as to 1/48 of the total shares monthly until fully vested, subject to the Reporting Person's provision of service to the Issuer on each vesting date.

SEC source: 0001562180-24-000338 · primarydocument.xml · derivative · entry 3

Huang Jane · CIK 0001683913 · President, CMO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 84,375

Underlying: Common Stock · 9,375 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 Restricted Stock Unit ("RSU") represents a contingent right to receive one share of Issuer's Common Stock.

F3 · derivative.exercise_date: The RSUs were granted on May 2, 2022 and vest according to the reporting person's employment agreement. The RSUs vested as to 1/4 of the total shares on April 4, 2023, and 1/16 of the remaining shares shall vest quarterly thereafter until fully vested, subject to the continued service of the Reporting Person to the Issuer through each vesting date.

F3 · derivative.expiration_date: The RSUs were granted on May 2, 2022 and vest according to the reporting person's employment agreement. The RSUs vested as to 1/4 of the total shares on April 4, 2023, and 1/16 of the remaining shares shall vest quarterly thereafter until fully vested, subject to the continued service of the Reporting Person to the Issuer through each vesting date.

SEC source: 0001562180-24-000338 · primarydocument.xml · nonDerivative · entry 2

Huang Jane · CIK 0001683913 · President, CMO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 45,259

F2 · shares: Represents shares withheld by the Issuer to satisfy the tax withholding obligation in connection with the vesting of RSUs.

SEC source: 0001562180-24-000338 · primarydocument.xml · nonDerivative · entry 1

Huang Jane · CIK 0001683913 · President, CMO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 49,103

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 Restricted Stock Unit ("RSU") represents a contingent right to receive one share of Issuer's Common Stock.

SEC source: 0001209191-23-058488 · doc4.xml · derivative · entry 2

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

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

BAKER JULIAN · CIK 0001087939 · Director · 10% owner

BAKER FELIX · CIK 0001087940 · Director · 10% owner

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

Baker Brothers Life Sciences LP · CIK 0001363364 · 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: 17,968,343

Underlying: Common Stock · 7,343,307 shares

Expires not disclosed

F1 · derivative.exercise_price: 667, L.P. ("667") and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds") purchased 593,452 and 7,343,307 warrants to purchase voting common stock ("Common Stock") of Prelude Therapeutics Incorporated (the "Issuer") ("Prefunded Warrants"), respectively, for $3.1499 per share pursuant to a private placement with the Issuer that closed on December 13, 2023. The Prefunded Warrants have no expiration date and are exercisable at an exercise price of $0.0001 per share immediately at any time at the option of the holder on a 1-for-1 basis into Common Stock to the extent that after giving effect to such exercise the holders thereof, together with their affiliates and any members of a Section 13(d) group with such holders, would beneficially own, for purposes of Rule 13d-3 under the Securities Act of 1934, as amended, no more than 4.99% of the outstanding shares of Common Stock (the "Maximum Percentage") immediately prior to and following such exercise.

F1 · derivative.exercise_date: 667, L.P. ("667") and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds") purchased 593,452 and 7,343,307 warrants to purchase voting common stock ("Common Stock") of Prelude Therapeutics Incorporated (the "Issuer") ("Prefunded Warrants"), respectively, for $3.1499 per share pursuant to a private placement with the Issuer that closed on December 13, 2023. The Prefunded Warrants have no expiration date and are exercisable at an exercise price of $0.0001 per share immediately at any time at the option of the holder on a 1-for-1 basis into Common Stock to the extent that after giving effect to such exercise the holders thereof, together with their affiliates and any members of a Section 13(d) group with such holders, would beneficially own, for purposes of Rule 13d-3 under the Securities Act of 1934, as amended, no more than 4.99% of the outstanding shares of Common Stock (the "Maximum Percentage") immediately prior to and following such exercise.

F2 · derivative.exercise_date: By written notice to the Issuer, the Funds may from time to time increase or decrease the Maximum Percentage applicable to that Fund to any other percentage not in excess of 19.99%. Any such increase will not be effective until the 61st day after such notice is delivered to the Issuer.

F1 · derivative.expiration_date: 667, L.P. ("667") and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds") purchased 593,452 and 7,343,307 warrants to purchase voting common stock ("Common Stock") of Prelude Therapeutics Incorporated (the "Issuer") ("Prefunded Warrants"), respectively, for $3.1499 per share pursuant to a private placement with the Issuer that closed on December 13, 2023. The Prefunded Warrants have no expiration date and are exercisable at an exercise price of $0.0001 per share immediately at any time at the option of the holder on a 1-for-1 basis into Common Stock to the extent that after giving effect to such exercise the holders thereof, together with their affiliates and any members of a Section 13(d) group with such holders, would beneficially own, for purposes of Rule 13d-3 under the Securities Act of 1934, as amended, no more than 4.99% of the outstanding shares of Common Stock (the "Maximum Percentage") immediately prior to and following such exercise.

F2 · derivative.expiration_date: By written notice to the Issuer, the Funds may from time to time increase or decrease the Maximum Percentage applicable to that Fund to any other percentage not in excess of 19.99%. Any such increase will not be effective until the 61st day after such notice is delivered to the Issuer.

F3 · ownership.nature: Baker Bros. Advisors LP (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 by the Funds. Baker Bros. Advisors (GP) LLC (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 by 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 by the Funds.

F4 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by 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: 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, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the securities reported in column 7 of Table II beneficially owned by 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: 0001209191-23-058488 · doc4.xml · derivative · entry 1

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

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

BAKER JULIAN · CIK 0001087939 · Director · 10% owner

BAKER FELIX · CIK 0001087940 · Director · 10% owner

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

Baker Brothers Life Sciences LP · CIK 0001363364 · 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: 1,563,672

Underlying: Common Stock · 593,452 shares

Expires not disclosed

F1 · derivative.exercise_price: 667, L.P. ("667") and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds") purchased 593,452 and 7,343,307 warrants to purchase voting common stock ("Common Stock") of Prelude Therapeutics Incorporated (the "Issuer") ("Prefunded Warrants"), respectively, for $3.1499 per share pursuant to a private placement with the Issuer that closed on December 13, 2023. The Prefunded Warrants have no expiration date and are exercisable at an exercise price of $0.0001 per share immediately at any time at the option of the holder on a 1-for-1 basis into Common Stock to the extent that after giving effect to such exercise the holders thereof, together with their affiliates and any members of a Section 13(d) group with such holders, would beneficially own, for purposes of Rule 13d-3 under the Securities Act of 1934, as amended, no more than 4.99% of the outstanding shares of Common Stock (the "Maximum Percentage") immediately prior to and following such exercise.

F1 · derivative.exercise_date: 667, L.P. ("667") and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds") purchased 593,452 and 7,343,307 warrants to purchase voting common stock ("Common Stock") of Prelude Therapeutics Incorporated (the "Issuer") ("Prefunded Warrants"), respectively, for $3.1499 per share pursuant to a private placement with the Issuer that closed on December 13, 2023. The Prefunded Warrants have no expiration date and are exercisable at an exercise price of $0.0001 per share immediately at any time at the option of the holder on a 1-for-1 basis into Common Stock to the extent that after giving effect to such exercise the holders thereof, together with their affiliates and any members of a Section 13(d) group with such holders, would beneficially own, for purposes of Rule 13d-3 under the Securities Act of 1934, as amended, no more than 4.99% of the outstanding shares of Common Stock (the "Maximum Percentage") immediately prior to and following such exercise.

F2 · derivative.exercise_date: By written notice to the Issuer, the Funds may from time to time increase or decrease the Maximum Percentage applicable to that Fund to any other percentage not in excess of 19.99%. Any such increase will not be effective until the 61st day after such notice is delivered to the Issuer.

F1 · derivative.expiration_date: 667, L.P. ("667") and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds") purchased 593,452 and 7,343,307 warrants to purchase voting common stock ("Common Stock") of Prelude Therapeutics Incorporated (the "Issuer") ("Prefunded Warrants"), respectively, for $3.1499 per share pursuant to a private placement with the Issuer that closed on December 13, 2023. The Prefunded Warrants have no expiration date and are exercisable at an exercise price of $0.0001 per share immediately at any time at the option of the holder on a 1-for-1 basis into Common Stock to the extent that after giving effect to such exercise the holders thereof, together with their affiliates and any members of a Section 13(d) group with such holders, would beneficially own, for purposes of Rule 13d-3 under the Securities Act of 1934, as amended, no more than 4.99% of the outstanding shares of Common Stock (the "Maximum Percentage") immediately prior to and following such exercise.

F2 · derivative.expiration_date: By written notice to the Issuer, the Funds may from time to time increase or decrease the Maximum Percentage applicable to that Fund to any other percentage not in excess of 19.99%. Any such increase will not be effective until the 61st day after such notice is delivered to the Issuer.

F3 · ownership.nature: Baker Bros. Advisors LP (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 by the Funds. Baker Bros. Advisors (GP) LLC (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 by 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 by the Funds.

F4 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by 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 securities reported in column 7 of Table II directly held by 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.

SEC source: 0001562180-23-007230 · primarydocument.xml · derivative · entry 2

Huang Jane · CIK 0001683913 · President, CMO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 93,750

Underlying: Common Stock · 9,375 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 Restricted Stock Unit ("RSU") represents a contingent right to receive one share of Issuer's Common Stock.

F2 · derivative.exercise_date: The RSUs were granted on May 2, 2022 and vest according to the reporting person's employment agreement. The RSUs vested as to 1/4 of the total shares on April 4, 2023, and 1/16 of the remaining shares shall vest quarterly thereafter until fully vested, subject to the continued service of the Reporting Person to the Issuer through each vesting date.

F2 · derivative.expiration_date: The RSUs were granted on May 2, 2022 and vest according to the reporting person's employment agreement. The RSUs vested as to 1/4 of the total shares on April 4, 2023, and 1/16 of the remaining shares shall vest quarterly thereafter until fully vested, subject to the continued service of the Reporting Person to the Issuer through each vesting date.

SEC source: 0001562180-23-007230 · primarydocument.xml · nonDerivative · entry 1

Huang Jane · CIK 0001683913 · President, CMO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 39,728

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 Restricted Stock Unit ("RSU") represents a contingent right to receive one share of Issuer's Common Stock.

SEC source: 0001209191-23-041553 · doc4.xml · derivative · entry 3

Huang Jane · CIK 0001683913 · President, CMO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 103,125

Underlying: Common Stock · 9,375 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 restricted stock unit ("RSU") represents a contingent right to receive one share of Issuer's Common Stock.

F3 · derivative.exercise_date: The RSUs were granted on May 2, 2022 and vest according to the reporting person's employment agreement. The RSUs vested as to 1/4 of the total shares on April 4, 2023, and 1/16 of the remaining shares shall vest quarterly thereafter until fully vested, subject to the continued service of the Reporting Person to the Issuer through each vesting date.

F3 · derivative.expiration_date: The RSUs were granted on May 2, 2022 and vest according to the reporting person's employment agreement. The RSUs vested as to 1/4 of the total shares on April 4, 2023, and 1/16 of the remaining shares shall vest quarterly thereafter until fully vested, subject to the continued service of the Reporting Person to the Issuer through each vesting date.

SEC source: 0001209191-23-041553 · doc4.xml · nonDerivative · entry 2

Huang Jane · CIK 0001683913 · President, CMO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 30,353

F2 · shares: Represents shares withheld by the Issuer to satisfy the tax withholding obligation in connection with the vesting of RSUs.

SEC source: 0001209191-23-041553 · doc4.xml · nonDerivative · entry 1

Huang Jane · CIK 0001683913 · President, CMO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 33,595

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 restricted stock unit ("RSU") represents a contingent right to receive one share of Issuer's Common Stock.

SEC source: 0001209191-23-038808 · doc4.xml · derivative · entry 2

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

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

BAKER JULIAN · CIK 0001087939 · Director · 10% owner

BAKER FELIX · CIK 0001087940 · Director · 10% owner

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

Baker Brothers Life Sciences LP · CIK 0001363364 · 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: 23,500

Underlying: Common Stock · 23,500 shares

Expires 2033-06-15

F1 · shares: Includes 23,500 non-qualified stock options ("Stock Options") exercisable solely into common stock ("Common Stock") of Prelude Therapeutics Incorporated (the "Issuer") granted by the Issuer to Julian C. Baker, a managing member of Baker Bros. Advisors (GP) LLC (the "Adviser GP"), on June 16, 2023, in his capacity as a director of the Issuer, pursuant to the Issuer's 2020 Stock Incentive Plan, as Amended and Restated ("Incentive Plan") The Stock Options have a strike price of $5.56 per share, and vest on the earlier of the first anniversary of the grant date or the date of the next annual general shareholders' meeting of the Issuer, subject to Julian C. Baker's continued service on the board of directors of the Issuer (the "Board") or an earlier change in control of the Issuer. The Stock Options expire on June 15, 2033. Julian C. Baker serves on the Board as a representative of the Funds (as defined below) and their affiliates.

F1 · derivative.exercise_date: Includes 23,500 non-qualified stock options ("Stock Options") exercisable solely into common stock ("Common Stock") of Prelude Therapeutics Incorporated (the "Issuer") granted by the Issuer to Julian C. Baker, a managing member of Baker Bros. Advisors (GP) LLC (the "Adviser GP"), on June 16, 2023, in his capacity as a director of the Issuer, pursuant to the Issuer's 2020 Stock Incentive Plan, as Amended and Restated ("Incentive Plan") The Stock Options have a strike price of $5.56 per share, and vest on the earlier of the first anniversary of the grant date or the date of the next annual general shareholders' meeting of the Issuer, subject to Julian C. Baker's continued service on the board of directors of the Issuer (the "Board") or an earlier change in control of the Issuer. The Stock Options expire on June 15, 2033. Julian C. Baker serves on the Board as a representative of the Funds (as defined below) and their affiliates.

F1 · ownership.nature: Includes 23,500 non-qualified stock options ("Stock Options") exercisable solely into common stock ("Common Stock") of Prelude Therapeutics Incorporated (the "Issuer") granted by the Issuer to Julian C. Baker, a managing member of Baker Bros. Advisors (GP) LLC (the "Adviser GP"), on June 16, 2023, in his capacity as a director of the Issuer, pursuant to the Issuer's 2020 Stock Incentive Plan, as Amended and Restated ("Incentive Plan") The Stock Options have a strike price of $5.56 per share, and vest on the earlier of the first anniversary of the grant date or the date of the next annual general shareholders' meeting of the Issuer, subject to Julian C. Baker's continued service on the board of directors of the Issuer (the "Board") or an earlier change in control of the Issuer. The Stock Options expire on June 15, 2033. Julian C. Baker serves on the Board as a representative of the Funds (as defined below) and their affiliates.

F3 · ownership.nature: Pursuant to the policies of Baker Bros. Advisors LP (the "Adviser"), Julian C. Baker does not have a right to any of the Issuer's securities issued as compensation for his service on the Board and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the Stock Options. Solely as a result of their ownership interest 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).

F4 · ownership.nature: Pursuant to agreements between Julian C. Baker and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the Stock Options and any Common Stock received as a result of the exercise of Stock Options.

F5 · ownership.nature: The acquisition of Stock Options reported on this form represents a single grant to Julian C. Baker of 23,500 Stock Options on Table II. This grant of 23,500 Stock Options for Julian C. Baker is reported for each of the Funds as each has an indirect pecuniary interest in such securities.

F6 · 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 directly by the Funds or 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 directly by the Funds or for the benefit of the Funds. The general partners of the Funds have relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds of for the benefit of the Funds.

F7 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or 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.

F8 · 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: 0001209191-23-038808 · doc4.xml · derivative · entry 1

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

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

BAKER JULIAN · CIK 0001087939 · Director · 10% owner

BAKER FELIX · CIK 0001087940 · Director · 10% owner

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

Baker Brothers Life Sciences LP · CIK 0001363364 · 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: 23,500

Underlying: Common Stock · 23,500 shares

Expires 2033-06-15

F1 · shares: Includes 23,500 non-qualified stock options ("Stock Options") exercisable solely into common stock ("Common Stock") of Prelude Therapeutics Incorporated (the "Issuer") granted by the Issuer to Julian C. Baker, a managing member of Baker Bros. Advisors (GP) LLC (the "Adviser GP"), on June 16, 2023, in his capacity as a director of the Issuer, pursuant to the Issuer's 2020 Stock Incentive Plan, as Amended and Restated ("Incentive Plan") The Stock Options have a strike price of $5.56 per share, and vest on the earlier of the first anniversary of the grant date or the date of the next annual general shareholders' meeting of the Issuer, subject to Julian C. Baker's continued service on the board of directors of the Issuer (the "Board") or an earlier change in control of the Issuer. The Stock Options expire on June 15, 2033. Julian C. Baker serves on the Board as a representative of the Funds (as defined below) and their affiliates.

F1 · derivative.exercise_date: Includes 23,500 non-qualified stock options ("Stock Options") exercisable solely into common stock ("Common Stock") of Prelude Therapeutics Incorporated (the "Issuer") granted by the Issuer to Julian C. Baker, a managing member of Baker Bros. Advisors (GP) LLC (the "Adviser GP"), on June 16, 2023, in his capacity as a director of the Issuer, pursuant to the Issuer's 2020 Stock Incentive Plan, as Amended and Restated ("Incentive Plan") The Stock Options have a strike price of $5.56 per share, and vest on the earlier of the first anniversary of the grant date or the date of the next annual general shareholders' meeting of the Issuer, subject to Julian C. Baker's continued service on the board of directors of the Issuer (the "Board") or an earlier change in control of the Issuer. The Stock Options expire on June 15, 2033. Julian C. Baker serves on the Board as a representative of the Funds (as defined below) and their affiliates.

F1 · ownership.nature: Includes 23,500 non-qualified stock options ("Stock Options") exercisable solely into common stock ("Common Stock") of Prelude Therapeutics Incorporated (the "Issuer") granted by the Issuer to Julian C. Baker, a managing member of Baker Bros. Advisors (GP) LLC (the "Adviser GP"), on June 16, 2023, in his capacity as a director of the Issuer, pursuant to the Issuer's 2020 Stock Incentive Plan, as Amended and Restated ("Incentive Plan") The Stock Options have a strike price of $5.56 per share, and vest on the earlier of the first anniversary of the grant date or the date of the next annual general shareholders' meeting of the Issuer, subject to Julian C. Baker's continued service on the board of directors of the Issuer (the "Board") or an earlier change in control of the Issuer. The Stock Options expire on June 15, 2033. Julian C. Baker serves on the Board as a representative of the Funds (as defined below) and their affiliates.

F2 · 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, L.P. ("667" and together with Baker Brothers Life Sciences, L.P. ("Life Sciences"), the "Funds"), 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.

F3 · ownership.nature: Pursuant to the policies of Baker Bros. Advisors LP (the "Adviser"), Julian C. Baker does not have a right to any of the Issuer's securities issued as compensation for his service on the Board and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the Stock Options. Solely as a result of their ownership interest 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).

F4 · ownership.nature: Pursuant to agreements between Julian C. Baker and the Adviser and the policies of the Adviser, the Adviser has voting and dispositive power over the Stock Options and any Common Stock received as a result of the exercise of Stock Options.

F5 · ownership.nature: The acquisition of Stock Options reported on this form represents a single grant to Julian C. Baker of 23,500 Stock Options on Table II. This grant of 23,500 Stock Options for Julian C. Baker is reported for each of the Funds as each has an indirect pecuniary interest in such securities.

F6 · 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 directly by the Funds or 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 directly by the Funds or for the benefit of the Funds. The general partners of the Funds have relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held directly by the Funds of for the benefit of the Funds.

F7 · ownership.nature: Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds or 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.

SEC source: 0001209191-23-038771 · doc4.xml · derivative · entry 1

Bonita David P · CIK 0001572451 · Director · 10% owner

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 23,500

Underlying: Common Stock · 23,500 shares

Expires 2033-06-15

F1 · derivative.exercise_date: The option award will fully vest upon the earlier of (a) the Issuer's next annual stockholder meeting, or (b) the one-year anniversary of the grant date, subject to the Reporting Person's provision of service to the Issuer on each vesting date.

F2 · ownership.direct: Pursuant to an agreement with OrbiMed Advisors LLC and OrbiMed Capital GP VI LLC, the Reporting Person is obligated to transfer any securities issued under any such stock options or other awards, or the economic benefit thereof, to OrbiMed Advisors LLC and OrbiMed Capital GP VI LLC, which will in turn ensure that such securities or economic benefits are provided to OrbiMed Private Investments VI, LP.

SEC source: 0001209191-23-038770 · doc4.xml · derivative · entry 1

Babler Martin · CIK 0001435618 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 23,500

Underlying: Common Stock · 23,500 shares

Expires 2033-06-15

F1 · derivative.exercise_date: The option award will fully vest upon the earlier of (a) the Issuer's next annual stockholder meeting, or (b) the one-year anniversary of the grant date, subject to the Reporting Person's provision of service to the Issuer on each vesting date.

SEC source: 0001209191-23-038774 · doc4.xml · derivative · entry 1

FRIEDMAN PAUL A · CIK 0001236927 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 23,500

Underlying: Common Stock · 23,500 shares

Expires 2033-06-15

F1 · derivative.exercise_date: The option award will fully vest upon the earlier of (a) the Issuer's next annual stockholder meeting, or (b) the one-year anniversary of the grant date, subject to the Reporting Person's provision of service to the Issuer on each vesting date.

SEC source: 0001209191-23-038773 · doc4.xml · derivative · entry 1

Dier Mardi · CIK 0001574591 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 23,500

Underlying: Common Stock · 23,500 shares

Expires 2033-06-15

F1 · derivative.exercise_date: The option award will fully vest upon the earlier of (a) the Issuer's next annual stockholder meeting, or (b) the one-year anniversary of the grant date, subject to the Reporting Person's provision of service to the Issuer on each vesting date.