X0206 3 2020-09-15 0 0001720580 Adicet Bio, Inc. ACET 0001615374 OrbiMed Capital GP V LLC 601 LEXINGTON AVENUE 54TH FLOOR NEW YORK NY 10022-4629 1 0 0 0 0001682093 OrbiMed Advisors Israel II Ltd 89 MEDINAT HAYEHUDIM ST., BUILDING E HERZLIYA L3 4614001 ISRAEL 1 0 0 0 0001682090 OrbiMed Israel GP II, L.P. 89 MEDINAT HAYEHUDIM ST., BUILDING E HERZLIYA L3 4614001 ISRAEL 1 0 0 0 0001569590 OrbiMed Israel GP Ltd. 89 MEDINAT HAYEHUDIM ST., BUILDING E HERZLIYA L3 4614001 ISRAEL 1 0 0 0 0001569821 OrbiMed Israel BioFund GP Limited Partnership 89 MEDINAT HAYEHUDIM ST., BUILDING E HERZLIYA L3 4614001 ISRAEL 1 0 0 0 No securities are beneficially owned 0 I See Footnote This report is being jointly filed by OrbiMed Capital GP V LLC, OrbiMed Israel BioFund GP Limited, OrbiMed Israel GP Ltd., OrbiMed Israel Partners II, L.P., and OrbiMed Israel GP II, L.P. The Reporting Persons have designated Carl L. Gordon ("Gordon") and Erez Chimovits ("Chimovits") to serve on the Issuer's board of directors. This report shall not be deemed an admission that any of the Reporting Persons, Gordon, or Chimovits is a beneficial owner of the Issuer's securities for the purpose of Section 16 of the Exchange Act, or for any other purpose. OrbiMed Capital GP V LLC, /s/ Douglas Coon, Chief Compliance Officer 2020-09-17 OrbiMed Israel BioFund GP Limited, /s/ Douglas Coon, Chief Compliance Officer 2020-09-17 OrbiMed Israel GP Ltd., /s/ Douglas Coon, Chief Compliance Officer 2020-09-17 OrbiMed Israel Partners II, L.P., /s/ Douglas Coon, Chief Compliance Officer 2020-09-17 OrbiMed Israel GP II, L.P., /s/ Douglas Coon, Chief Compliance Officer 2020-09-17