X0206 3 2021-02-03 0 0001829802 Sensei Biotherapeutics, Inc. SNSE 0001843544 Fjaellskog Marie-Louise C/O SENSEI BIOTHERAPEUTICS, INC. 1405 RESEARCH BLVD, SUITE 125 ROCKVILLE MD 20850 0 1 0 0 Chief Medical Officer Stock Option (Right to Buy) 3.22 2030-08-04 Common Stock 208333 D Twenty-five percent (25%) of the shares subject to the option vest on the first anniversary of the vesting commencement date June 15,2020, and 1/48th of the shares subject to the option vest monthly thereafter over thirty-six (36) months, subject to Reporting Person's continuous service as of each such date. Exhibit 24- Power of Attorney /s/ Mark Ballantyne, Attorney-in-Fact 2021-02-03