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                                                                EXHIBIT 10.5


LOGO
                          SILICON VALLEY BANK
                          AMENDMENT TO LOAN AND SECURITY AGREEMENT

BORROWER:                 IMMUSOL, INC.
ADDRESS:                  3050 SCIENCE PARK DRIVE
                          SAN DIEGO, CALIFORNIA  92121

DATE:            MAY 15, 1996

         THIS AMENDMENT TO LOAN AND SECURITY AGREEMENT is entered into between
SILICON VALLEY BANK ("Silicon") and the borrower named above (the "Borrower").

         The Parties agree to amend the Loan and Security Agreement between
them, dated April 3, 1996 (the "Loan Agreement"), as follows.  (Capitalized
terms used but not defined in this Amendment, shall have the meanings set forth
in the Loan Agreement.)

         1.      EXTENDED APPLICABLE PERIOD FOR ADVANCE RATE SCHEDULE.  The
second paragraph of the "Credit Limit (Section 1.1)" as set forth in the
Schedule to Loan and Security Agreement is amended effective on the date hereof
to read as follows:

                 Each requested Loan for purchases of equipment shall be in an
                 amount not less than $50,000 and shall not exceed either (a)
                 100% of the invoice amount of new items of equipment that the
                 Borrower purchases on or after March 1, 1996 or (b) 50% of the
                 original invoice amount of items of equipment that the
                 Borrower has purchased not more than one year prior to the
                 date of the requested Loan.  In connection with the foregoing,
                 and prior to the making of any Loan, Borrower shall supply to
                 Silicon lists of invoices (including serial numbers) relating
                 to the equipment subject of the requested Loan and shall
                 supply such other information relating thereto as Silicon
                 requests.

         2.      REPRESENTATIONS TRUE.  Borrower represents and warrants to
Silicon that all representations and warranties set forth in the Loan
Agreement, as amended hereby, are true and correct.

         3.      GENERAL PROVISIONS.  This Amendment, the Loan Agreement, any
prior written amendments to the Loan Agreement signed by Silicon and the
Borrower, and the other written documents and agreements between Silicon and
the Borrower set forth in full all of the representations and agreements of the
parties with respect to the subject matter hereof and supersede all prior
discussions, representations, agreements and understandings between the parties
with respect to the subject hereof.  Except as herein expressly amended, all of
the terms  and provisions of the Loan Agreement, and all other documents and
agreements between Silicon and the Borrower shall continue in full force and
effect and the same are hereby ratified and confirmed.

BORROWER:                                  SILICON:

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IMMUSOL, INC.                              SILICON VALLEY BANK


By /s/ S. Goldenberg                       By /s/ R (illegible)              
   -------------------------------            -------------------------------
   Chairman and CEO
                                           Title SVP
                                                 ----------------------------

By _______________________________
   Secretary or Ass't Secretary