First Amendment to Loan and Security Agreement, effective July 31, 2017, by and among Cerus Corporation and Oxford Finance LLC, as collateral agent and a lender. 31.1 Certification of the Principal Executive Officer of Cerus Corporation pursuant to Section 302 of the Sarbanes-Oxley Act of 2002

Exhibit 10.3

FIRST AMENDMENT TO LOAN AND SECURITY AGREEMENT

THIS FIRST AMENDMENT to Loan and Security Agreement (this “Amendment”) is made effective as of July 31, 2017 (the “First Amendment Date”) and made, by and among OXFORD FINANCE LLC, a Delaware limited liability company with an office located at 133 North Fairfax Street, Alexandria, Virginia 22314 (in its individual capacity, “Oxford”; and in its capacity as Collateral Agent, “Collateral Agent”), the Lenders listed on Schedule 1.1 thereof from time to time including Oxford in its capacity as a Lender (each a “Lender” and collectively, the “Lenders”) and CERUS CORPORATION, a Delaware corporation with offices located at 2550 Stanwell Drive, Concord, CA  94520 (“Borrower”).

WHEREAS, Collateral Agent, Borrower and Lenders party thereto from time to time have entered into that certain Loan and Security Agreement, dated as of date hereof (as amended, supplemented or otherwise modified from time to time, the “Loan Agreement”) pursuant to which Lenders have provided to Borrower certain loans in accordance with the terms and conditions thereof; and

WHEREAS, Borrower, Lenders and Collateral Agent desire to amend certain provisions of the Loan Agreement as provided herein and subject to the terms and conditions set forth herein;

NOW, THEREFORE, in consideration of the promises, covenants and agreements contained herein, and other good and valuable consideration, the receipt and adequacy of which are hereby acknowledged, Borrower, Lenders and Collateral Agent hereby agree as follows:

(a)Availability.  (i) Subject to the terms and conditions of this Agreement, the Lenders agree, severally and not jointly, to make term loans to Borrower on the Effective Date in an aggregate amount of Thirty Million Dollars ($30,000,000.00) according to each Lender’s Term A Loan Commitment as set forth on Schedule 1.1 hereto (such term loans are hereinafter referred to singly as a “Term A Loan”, and collectively as the “Term A Loans”).  After repayment, no Term A Loan may be re‑borrowed.  Subject to the terms and conditions of the Original Agreement, the Lenders, severally and not jointly, loaned to Borrower advances according to each Lender’s Term Loan Commitment (as defined in the Original Agreement) as set forth on Schedule 1.1 of the Original Agreement (such term loans referred to singly as “Original Term Loan”, and collectively as “Original Term Loans”), of which an aggregate principal amount of Seventeen Million Six Hundred Thirty Thousand Five Hundred Nine Dollars and Forty Four cents ($17,630,509.44) remains outstanding on the date hereof and shall, as of the Effective Date, be governed by the terms and provisions of  this Agreement.  The Original Term Loans are evidenced by, among other things, : (1) that certain Term A Loan – Note No. 1, issued on June 30, 2014 (“Original Note 1”) in the original principal amount of Five Million Dollars ($5,000,000.00), of which Four Million Four Hundred Seven Thousand Four Hundred Forty Eight Dollars Thirty cents ($4,407,448.30) of principal amount remain outstanding; (2) that certain Term A Loan – Note No. 2, issued on June 30, 2014 (“Original Note 2”) in the original principal amount of Five Million Dollars ($5,000,000.00), of which Four Million Four Hundred Seven Thousand Four Hundred Forty Eight Dollars Thirty cents ($4,407,448.30) of principal amount remain outstanding; (3) that certain Term B Loan – Note 1, issued on June 15, 2015 (“Original Note 3”) in the original principal amount of Five Million Dollars ($5,000,000.00), of which Four Million Four Hundred Seven Thousand Eight Hundred  Six Dollars Forty Two cents ($4,407,806.42) of principal amount remain outstanding; and (4) that certain Term B Loan – Note 2, issued on June 15, 2015 (“Original Note 4,” and together with Original Note 1, Original Note 2 and Original Note 3, the “Original Notes”) in the original principal amount of Five Million Dollars ($5,000,000.00), of which Four Million Four Hundred Seven Thousand Eight Hundred  Six Dollars Forty Two cents ($4,407,806.42) of principal amount remain outstanding.  Each Original Note shall be amended and restated on the Effective Date and as amended and restated shall represent, effective as of the Effective Date, the respective principal amount of the Original Term Loans outstanding that is evidenced by such Original Note and set forth above as equivalent principal amount of the Term A Loans being issued hereunder and shall be governed in all respects by the terms of

this Agreement.  The balance of the aggregate principal amount of the Term A Loans shall be evidenced by Secured Promissory Notes issued hereunder.

Oxford provided terms loans earlier to Borrower, an aggregated principal amount of $17,630,509.44 of which is outstanding immediately prior to the Effective Date.  Such aggregate principal amount shall convert to Term A Loans hereunder and will be evidenced by Amended and Restated Promissory Notes showing applicable principal balances as of July 31, 2017.  New Secured Promissory Notes evidencing the Term A Loans hereunder shall be issued on the Effective Date in the respective amounts of $7,000,000.00 and $5,369,490.56.

2

[Balance of Page Intentionally Left Blank]

3

IN WITNESS WHEREOF, the parties hereto have caused this First Amendment to Loan and Security Agreement to be executed effective as of the date first set forth above.

[Signature page to First Amendment to Loan and Security Agreement]