X0306 4 2021-02-03 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 Stock Option (Right to Buy) 19.00 2021-02-03 4 A 0 16666 0.00 A 2031-02-02 Common Stock 16666 16666 D One thirty-sixth (1/36th) of the options granted shall vest and become exercisable each month following February 3, 2021, the Vesting Commencement Date, over three years such that the options shall be 100% vested on the third anniversary of the Vesting Commencement Date, subject to Continuous Service (as defined in the 2021 Equity Incentive Plan) of James Peyer on the Issuer's Board of Directors, through each such vesting date. Cambrian Biopharma, Inc. By: /s/ James Peyer, CEO 2021-02-05