Exhibit 10.38

FIRST AMENDMENT

TO

LOAN AND SECURITY AGREEMENT

THIS FIRST AMENDMENT to Loan and Security Agreement (this Amendment) is entered into as of March 3, 2011, by and between OXFORD FINANCE CORPORATIONa Delaware corporation
(Lender) whose address is 133 North Fairfax Street, Alexandria, Virginia 22314 and CERUS CORPORATION, a Delaware corporation (Borrower) whose address is 2550 Stanwell Drive, Concord, California 94520.

RECITALS

A.Lender and Borrower have entered into that certain Loan and Security Agreement dated as of March 31, 2010 (as the same may from time to time be further amended, modified, supplemented or
restated, the Loan Agreement).

B.Lender has extended credit to Borrower for the purposes permitted
in the Loan Agreement.

C.Borrower has requested that Lender amend the Loan Agreement to (i) modify the financial
covenants and (ii) make certain revisions to the Loan Agreement as more fully set forth herein.

D.Lender has
agreed to so amend certain provisions of the Loan Agreement, but only to the extent, in accordance with the terms, subject to the conditions and in reliance upon the representations and warranties set forth below.

AGREEMENT

NOW, THEREFORE, in consideration of the foregoing recitals and other good and valuable consideration, the receipt and adequacy of which is hereby acknowledged, and
intending to be legally bound, the parties hereto agree as follows:

1. Definitions. Capitalized terms used but
not defined in this Amendment shall have the meanings given to them in the Loan Agreement.

2. Amendments to Loan
Agreement.

2.1 Section 6.7 (Performance to Plan; Revenues). Section 6.7 of the Loan Agreement hereby is
amended and restated in its entirety to read as follows:

(a) Borrowers actual revenues, on a
trailing 6-month basis during calendar year 2010, shall be at least eighty percent (80%) of projected revenues, as set forth in Annex I hereto; (b) Borrowers actual revenues, on a trailing 6-month basis during calendar year 2011,
shall be at least eighty percent (80%) of projected revenues, as set forth in Annex I hereto; and (c) Borrowers actual revenues, determined in accordance with GAAP, shall be at least 5,700,000 quarterly, commencing January 2012
and for the duration of the term of this Agreement.



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CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS
BEEN OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION
PURSUANT TO RULE 24b-2 OF THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.



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2.2 Section 13.1 (Definitions). The following term and its respective definition
hereby is amended and restated in Section 13.1 of the Loan Agreement as follows:

Tranche
B Availability Period is the period from September 30, 2010 to September 30, 2011.

2.3Annex I to
the Loan Agreement hereby is amended and restated in the form of Annex I attached hereto.

3. Limitation of Amendments.

3.1The amendments set forth in Section 2, above, are effective for the purposes set forth herein and
shall be limited precisely as written and shall not be deemed to (a) be a consent to any amendment, waiver or modification of any other term or condition of any Loan Document, or (b) otherwise prejudice any right or remedy which Lender may
now have or may have in the future under or in connection with any Loan Document.

3.2This Amendment shall be
construed in connection with and as part of the Loan Documents and all terms, conditions, representations, warranties, covenants and agreements set forth in the Loan Documents, except as herein amended, are hereby ratified and confirmed and shall
remain in full force and effect.

4. Representations and Warranties. To induce Lender to enter into this
Amendment, Borrower hereby represents and warrants to Lenders as follows:

4.1Immediately after giving effect to this
Amendment (a) the representations and warranties contained in the Loan Documents are true, accurate and complete in all material respects as of the date hereof (except to the extent such representations and warranties relate to an earlier date,
in which case they are true and correct as of such date), and (b) no Event of Default has occurred and is continuing;

4.2Borrower has the power and authority to execute and deliver this Amendment and to perform its obligations under the Loan
Agreement, as amended by this Amendment;

4.3The organizational documents of Borrower delivered to Lender on the
Effective Date remain true, accurate and complete and have not been amended, supplemented or restated and are and continue to be in full force and effect;



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CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS
BEEN OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION
PURSUANT TO RULE 24b-2 OF THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.



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4.4The execution and delivery by Borrower of this Amendment and the performance by
Borrower of its obligations under the Loan Agreement, as amended by this Amendment, have been duly authorized;

4.5The
execution and delivery by Borrower of this Amendment and the performance by Borrower of its obligations under the Loan Agreement, as amended by this Amendment, do not and will not contravene (a) any material law or regulation binding on or
affecting Borrower, (b) any material contractual restriction with a Person binding on Borrower, (c) any order, judgment or decree of any court or other governmental or public body or authority, or subdivision thereof, binding on Borrower,
or (d) the organizational documents of Borrower;

4.6The execution and delivery by Borrower of this Amendment and
the performance by Borrower of its obligations under the Loan Agreement, as amended by this Amendment, do not require any order, consent, approval, license, authorization or validation of, or filing, recording or registration with, or exemption by
any governmental or public body or authority, or subdivision thereof, binding on either Borrower, except as already has been obtained or made; and

4.7This Amendment has been duly executed and delivered by Borrower and is the binding obligation of Borrower, enforceable against Borrower in accordance with its terms, except as such
enforceability may be limited by bankruptcy, insolvency, reorganization, liquidation, moratorium or other similar laws of general application and equitable principles relating to or affecting creditors rights.

5. Counterparts. This Amendment may be executed in any number of counterparts and all of such counterparts taken together
shall be deemed to constitute one and the same instrument.

6. Effectiveness. This Amendment shall be deemed
effective upon the due execution and delivery to Lender of this Amendment by each party hereto, and Borrowers payment of all Lender Expenses incurred through the date of this Amendment.

[Balance of Page Intentionally Left Blank]



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CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS
BEEN OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION
PURSUANT TO RULE 24b-2 OF THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.



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IN WITNESS WHEREOF, the parties hereto
have caused this Amendment to be duly executed and delivered as of the date first written above.



|                           |  |                                    |  |                   |  |        |  |                   
|-------------------------- |  | ---------------------------------- |  | ----------------- |  | ------ |  | ------------------
|LENDER:                    |  |                                    |  | BORROWER:        
|                           |  |                                   
|OXFORD FINANCE CORPORATION |  |                                    |  | CERUS CORPORATION
|                           |  |                                    |  |                  
|By:                        |  | /s/ John G. Henderson              |  |                   |  | By:    |  | /s/ Kevin D. Green
|Name:                      |  | John G. Henderson                  |  |                   |  | Name:  |  | Kevin D. Green    
|Title:                     |  | Vice President and General Counsel |  |                   |  | Title: |  | V.P. Finance & CAO

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



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CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS
BEEN OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION
PURSUANT TO RULE 24b-2 OF THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.



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ANNEX I

(Revised Projected Revenues)

[Please see attached.]

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[ * ] =
CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS
BEEN OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION
PURSUANT TO RULE 24b-2 OF THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.