X0306 4/A 2022-02-15 2022-02-17 0 0001829802 Sensei Biotherapeutics, Inc. SNSE 0001594129 Pierce Robert Hamilton C/O SENSEI BIOTHERAPEUTICS, INC. 451 D STREET, SUITE 710 BOSTON MA 02210 0 1 0 0 Chief R&D Officer Common Stock 94463 D On February 17, 2022, the reporting person filed a Form 4 which inadvertently reported an incorrect number of shares owned. This amendment is filed solely to correct the number of shares owned. /s/ Mark Ballantyne, Attorney-in-Fact 2022-09-01