X0508 4 2023-08-14 0 0001720580 Adicet Bio, Inc. ACET 0001340875 Schor Chen C/O ADICET BIO, INC. 200 BERKELEY STREET, 19TH FLOOR BOSTON MA 02116 1 1 0 0 President & CEO 0 Stock Option (Right to Buy) 8.89 2023-08-14 4 D 0 36857 0.00 D 2029-12-05 Common Stock 36857 0 D Stock Option (Right to Buy) 2.14 2023-08-14 4 A 0 36857 0.00 A 2029-12-05 Common Stock 36857 36857 D Stock Option (Right to Buy) 16.11 2023-08-14 4 D 0 872111 0.00 D 2030-09-16 Common Stock 872111 0 D Stock Option (Right to Buy) 2.14 2023-08-14 4 A 0 872111 0.00 A 2030-09-16 Common Stock 872111 872111 D Stock Option (Right to Buy) 13.27 2023-08-14 4 D 0 240000 0.00 D 2031-01-12 Common Stock 240000 0 D Stock Option (Right to Buy) 2.14 2023-08-14 4 A 0 240000 0.00 A 2031-01-12 Common Stock 240000 240000 D Stock Option (Right to Buy) 16.82 2023-08-14 4 D 0 421600 0.00 D 2031-02-11 Common Stock 421600 0 D Stock Option (Right to Buy) 2.14 2023-08-14 4 A 0 421600 0.00 A 2031-02-11 Common Stock 421600 421600 D Stock Option (Right to Buy) 15.52 2023-08-14 4 D 0 295000 0.00 D 2032-01-06 Common Stock 295000 0 D Stock Option (Right to Buy) 2.14 2023-08-14 4 A 0 295000 0.00 A 2032-01-06 Common Stock 295000 295000 D Stock Option (Right to Buy) 9.05 2023-08-14 4 D 0 384900 0.00 D 2033-01-23 Common Stock 384900 0 D Stock Option (Right to Buy) 2.14 2023-08-14 4 A 0 384900 0.00 A 2033-01-23 Common Stock 384900 384900 D Reflects 1-for-7 reverse stock split effected by the Issuer on September 15, 2020. 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 are fully vested and exercisable as of the date hereof. 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 employment is terminated by the Issuer with cause or by the Reporting Person or (b) the option is exercised. The shares subject to this option shall vest in forty-eight (48) equal installments on each monthly anniversary following September 17, 2020, subject to the Reporting Person's continued service with the Issuer as of the applicable vesting date. The shares subject to this option shall vest in forty-eight (48) equal installments on each monthly anniversary following January 13, 2021, subject to the Reporting Person's continued service with the Issuer as of the applicable vesting date. The shares subject to this option shall vest in forty-eight (48) equal installments on each monthly anniversary following February 12, 2021, subject to the Reporting Person's continued service with the Issuer as of the applicable vesting date. The shares subject to this option shall vest in forty-eight (48) equal installments on each monthly anniversary following January 7, 2022, subject to the Reporting Person's continued service with the Issuer as of the applicable vesting date. The shares subject to this option shall vest in forty-eight (48) equal installments on each monthly anniversary following January 24, 2023, subject to the Reporting Person's continued service with the Issuer as of the applicable vesting date. /s/ Nick Harvey, Attorney-in-Fact 2023-08-16