X0508 4 2023-08-14 0 0001720580 Adicet Bio, Inc. ACET 0001364719 Kauffman Michael C/O ADICET BIO, INC. 200 BERKELEY STREET, 19TH FLOOR BOSTON MA 02116 1 0 0 0 0 Stock Option (Right to Buy) 9.39 2023-08-14 4 D 0 37000 0.00 D 2031-11-16 Common Stock 37000 0 D Stock Option (Right to Buy) 2.14 2023-08-14 4 A 0 37000 0.00 A 2031-11-16 Common Stock 37000 37000 D Stock Option (Right to Buy) 11.49 2023-08-14 4 D 0 18500 0.00 D 2032-06-01 Common Stock 18500 0 D Stock Option (Right to Buy) 2.14 2023-08-14 4 A 0 18500 0.00 A 2032-06-01 Common Stock 18500 18500 D Stock Option (Right to Buy) 5.195 2023-08-14 4 D 0 26400 0.00 D 2033-05-31 Common Stock 26400 0 D Stock Option (Right to Buy) 2.14 2023-08-14 4 A 0 26400 0.00 A 2033-05-31 Common Stock 26400 26400 D On August 8, 2023, the Issuer's Board of Directors approved an option repricing (the "Repricing"), effective as of August 14, 2023 (the "Effective Date"). All of the other terms of the options remain unchanged. Such transactions were exempt pursuant to Rule 16b-6(d) and Rule 16b-3 of the Exchange Act, as applicable. The shares subject to this option shall vest in thirty-six (36) equal monthly installments commencing on November 17, 2021, subject to the Reporting Person's continued service on the Issuer's Board of Directors as of the applicable vesting date. The exercise price of the option is $2.14 per share, representing the fair market value per share of the Issuer's Common Stock on the Effective Date; provided that the repriced option will revert to its original exercise price if, prior to the first anniversary of the Effective Date, (a) the Reporting Person's service on the Issuer's Board of Directors is terminated by the Issuer with cause or by the Reporting Person or (b) the option is exercised. The shares subject to this option are fully vested and exercisable as of the date hereof. The shares subject to this option shall vest in full on the earlier to occur of (a) June 1, 2024 or (b) the date of the Issuer's 2024 annual meeting of stockholders, subject to the Reporting Person's continued service on the Issuer's Board of Directors as of the applicable vesting date. /s/ Nick Harvey, Attorney-in-Fact 2023-08-16