SECURED PROMISSORY NOTE (Term A Loan)

FOR VALUE RECEIVED, the undersigned, MABVAX THERAPEUTICS HOLDINGS, INC., a Delaware corporation with offices located at 11588 Sorrento Valley Road, Suite 20, San Diego, CA 92121 (“Holdings”), and MABVAX THERAPEUTICS, INC., a Delaware corporation with offices located at 11588 Sorrento Valley Road, Suite 20, San Diego, CA 92121 (“MabVax” and together with Holdings, individually and collectively, jointly and severally, “Borrower”), HEREBY PROMISES TO PAY to the order of OXFORD FINANCE LLC (“Lender”) the principal amount of _______ (_______) or such lesser amount as shall equal the outstanding principal balance of the Term A Loan made to Borrower by Lender, plus interest on the aggregate unpaid principal amount of such Term A Loan, at the rates and in accordance with the terms of the Loan and Security Agreement dated January 15, 2016, by and among Borrower, Lender, Oxford Finance LLC, as Collateral Agent, and the other Lenders from time to time party thereto (as amended, restated, supplemented or otherwise modified from time to time, the “Loan Agreement”).  If not sooner paid, the entire principal amount and all accrued and unpaid interest hereunder shall be due and payable on the Maturity Date as set forth in the Loan Agreement.  Any capitalized term not otherwise defined herein shall have the meaning attributed to such term in the Loan Agreement.

Principal, interest and all other amounts due with respect to the Term A Loan, are payable in lawful money of the United States of America to Lender as set forth in the Loan Agreement and this Secured Promissory Note (this “Note”).  The principal amount of this Note and the interest rate applicable thereto, and all payments made with respect thereto, shall be recorded by Lender and, prior to any transfer hereof, endorsed on the grid attached hereto which is part of this Note.