144 0001797409 XXXXXXXX LIVE 0001829802 Sensei Biotherapeutics, Inc. 001-39980 1405 RESEARCH BLVD, SUITE 125 ROCKVILLE MD 20850 (240) 243-8000 Cambrian BioPharma Inc 10% Stockholder Common Fidelity Brokerage Services LLC

245 Summer Street Boston MA 02110

155142 4956786.00 1340281 04/29/2026 NASDAQ Common 01/10/2020 Private Placement Issuer N 155142 01/10/2020 Cash/Check Y 04/29/2026 /s/ Daniel Gardea as a duly authorized representative of Fidelity Brokerage Services LLC, as attorney-in-fact for Cambrian BioPharma Inc.