X0306 4 2020-03-27 0 0001678660 Prelude Therapeutics Inc PRLD 0001572451 Bonita David P C/O PRELUDE THERAPEUTICS INCORPORATED 200 POWDER MILL ROAD WILMINGTON DE 19801 1 0 1 0 Common Stock 2020-09-25 4 P 0 526300 19.00 A 526300 I See footnote Common Stock 2020-09-25 4 P 0 710500 19.00 A 917412 I See footnote Common Stock 2020-09-29 4 C 0 8332779 A 9250191 I See footnote Director Stock Option (right to buy) 12.85 2020-09-24 4 A 0 46688 0.00 A 2030-09-01 Common Stock 46688 46688 D Series B Preferred Stock 2020-03-27 4 P 0 3681822 A Common Stock 3681822 7363644 I See footnote Series C Preferred Stock 2020-08-21 4 P 0 1033084 A Common Stock 1033084 1033084 I See footnote Series A Preferred Stock 2020-09-29 4 C 0 3294743 D Common Stock 3294743 0 I See footnote Series A Preferred Stock 2020-09-29 4 C 0 2196494 D Non-Voting Common Stock 2196494 0 I See footnote Series B Preferred Stock 2020-09-29 4 C 0 4418186 D Common Stock 4418186 0 I See footnote Series B Preferred Stock 2020-09-29 4 C 0 2945458 D Non-Voting Common Stock 2945458 0 I See footnote Series C Preferred Stock 2020-09-29 4 C 0 619850 D Common Stock 619850 0 I See footnote Series C Preferred Stock 2020-09-29 4 C 0 413234 D Non-Voting Common Stock 413234 0 I See footnote Non-Voting Common Stock 2020-09-29 4 C 0 5555186 A Common Stock 5555186 5555186 I See footnote These securities are held of record by OrbiMed Partners Master Fund Limited ("OPM"). OrbiMed Capital LLC ("OrbiMed Capital") is the investment advisor to OPM. OrbiMed Capital is a relying advisor of OrbiMed Advisors LLC ("OrbiMed Advisors"). OrbiMed Advisors and OrbiMed Capital exercise voting and investment power through a management committee comprised of the Carl L. Gordon, Sven H. Borho, and Jonathan T. Silverstein, each of whom disclaims beneficial ownership of the shares held by OPM. The Reporting Person is a member of OrbiMed Advisors. This report shall not be deemed an admission that any of the Reporting Person, OrbiMed Advisors, OrbiMed Capital or GP VI is a beneficial owner of such securities for the purpose of Section 16 of the Exchange Act, or for any other purpose. These securities are held of record by OrbiMed Private Investments VI, L.P. ("OPI VI"). OrbiMed Capital GP VI LLC ("GP VI") is the general partner of OPI VI and OrbiMed Advisors is the managing member of GP VI. The Reporting Person is a member of OrbiMed Advisors. By virtue of such relationships, GP VI and OrbiMed Advisors may be deemed to have voting power and investment power over the securities held by OPI VI and as a result, may be deemed to have beneficial ownership over such securities. OrbiMed Advisors exercises voting and investment power through a management committee comprised of Carl L. Gordon, Sven H. Borho, and Jonathan T. Silverstein, each of whom disclaims beneficial ownership of the shares held by OPI VI. Each share of the Issuer's Series A Preferred Stock, Series B Preferred Stock, and Series C Preferred Stock automatically converted into one share of the Issuer's Common Stock immediately prior to the closing of the Issuer's initial public offering and has no expiration date. The stock option vested as to 1/36 of the total shares monthly beginning on September 24, 2020 until fully vested, subject to the Reporting Person's provision of service to the Issuer on each vesting date. The Reporting Person is reporting the purchases of these securities, pursuant to Rule 16a-2(a) of the Exchange Act. Each share of the Issuer's Series B Preferred Stock and Series C Preferred Stock may be automatically converted into one share of the Issuer's Common Stock or, at the election of the holder and subject to certain conditions, Non-Voting Common Stock immediately prior to the closing of the Issuer's initial public offering and has no expiration date. Notwithstanding the foregoing, the option to convert into Non-Voting Common Stock shall be limited to no more than 40% of the aggregate shares of Common Stock issuable to such holder upon conversion of such holder's convertible preferred stock. As reported below, each share of the Issuer's Series B Preferred Stock and Series C Preferred Stock was automatically converted into one share of the Issuer's Common Stock or Non-Voting Common Stock immediately prior to the closing of the Issuer's initial public offering. The number of securities reported reflects the one-for-1.1566 reverse stock split of the Issuer's Common Stock and convertible preferred stock that was effected on September 18, 2020. Each share of the Issuer's Series A Preferred Stock, Series B Preferred Stock, and Series C Preferred Stock automatically converted into one share of the Issuer's Non-Voting Common Stock immediately prior to the closing of the Issuer's initial public offering and has no expiration date. Each share of the Issuer's Non-Voting Common Stock is convertible into one share of the Issuer's Common Stock at any time at the option of the holder without consideration subject to a 9.99% beneficial ownership limitation which may be increased or decreased by the holder upon 61 days' notice to the Issuer. /s/ Brian Piper, as Attorney-in-Fact for David P. Bonita 2020-09-30