X0306 4 2022-06-17 0 0001678660 Prelude Therapeutics Inc PRLD 0001263508 BAKER BROS. ADVISORS LP 860 WASHINGTON STREET, 3RD FLOOR NEW YORK NY 10014 1 0 1 0 0001551139 667, L.P. 860 WASHINGTON STREET, 3RD FLOOR NEW YORK NY 10014 1 0 1 0 0001087939 BAKER JULIAN 860 WASHINGTON STREET, 3RD FLOOR NEW YORK NY 10014 1 0 1 0 0001087940 BAKER FELIX 860 WASHINGTON STREET, 3RD FLOOR NEW YORK NY 10014 1 0 1 0 0001580575 Baker Bros. Advisors (GP) LLC 860 WASHINGTON STREET, 3RD FLOOR NEW YORK NY 10014 1 0 1 0 0001363364 Baker Brothers Life Sciences LP 860 WASHINGTON STREET, 3RD FLOOR NEW YORK NY 10014 1 0 1 0 Non-Qualified Stock Options (right to buy) 4.74 2022-06-17 4 A 0 34300 0.00 A 2032-06-16 Common Stock 34300 34300 I See Footnotes 34,300 non-qualified stock options ("Stock Options") exercisable solely into common stock ("Common Stock") of Prelude Therapeutics Incorporated (the "Issuer") were granted under the Issuer's 2020 Stock Incentive Plan, as Amended and Restated, to Julian C. 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 $4.74 per share, and vest upon the earlier to occur 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. Julian C. 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"). Pursuant to the policies of Baker Bros. Advisors LP (the "Adviser"), Julian C. 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 of 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 (i.e. no direct pecuniary interest). 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. 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. 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. 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. Julian C. Baker, a managing member of Baker Bros. Advisors (GP) LLC, the sole general partner of Baker Bros. Advisors LP, is a director of Prelude Therapeutics Incorporated (the "Issuer"). By virtue of their representation on the Board of Directors of the Issuer, for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, the reporting persons are deemed directors by deputization of the Issuer. By: Baker Bros. Advisors LP, Name: Scott L. Lessing, Title: President /s/ Scott L. Lessing 2022-06-22 Baker Bros. Advisors LP, Mgmt. Co. and Inv. Adviser to 667, L.P., pursuant to authority granted by Baker Biotech Capital, L.P., GP to 667, L.P. Name: Scott L. Lessing, Title: President /s/ Scott L. Lessing 2022-06-22 /s/ Julian C. Baker 2022-06-22 /s/ Felix J. Baker 2022-06-22 By: Baker Bros. Advisors (GP) LLC, Name: Scott L. Lessing, Title: President /s/ Scott L. Lessing 2022-06-22 Baker Bros. Advisors LP, Mgmt. Co. and Inv. Adviser to BAKER BROTHERS LIFE SCIENCES, L.P., pursuant to authority granted by Baker Brothers Life Sciences Capital, L.P., GP to Baker Brothers Life Sciences, L.P., Name: Scott L. Lessing, Title: President /s/ 2022-06-22