X0306 4 2021-02-18 0 0001829802 Sensei Biotherapeutics, Inc. SNSE 0001797409 Cambrian BioPharma Inc 19 MORRIS AVE BROOKLYN NAVY YARD BUILDING, 128 BROOKLYN NY 11025 0 0 1 0 Common Stock 2021-02-18 4 P 0 753 19.75 A 4690906 D These shares are held by Cambrian Biopharma, Inc., a Delaware corporation ("Cambrian"). The Chief Executive Officer of Cambrian, James Peyer, may direct the voting and disposition of the shares held by Cambrian, subject in certain instances to the approval of Cambrian's Board of Directors. Mr. Peyer disclaims beneficial ownership of such shares. Cambrian Biopharma, Inc. By: /s/ James Peyer 2021-02-19