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                                                                   Exhibit 10.72

                               FIRST AMENDMENT TO
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                  AMENDED AND RESTATED SECURED PROMISSORY NOTE
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         Corvas International, Inc., a Delaware corporation having a principal
place of business at 3030 Science Park Rd., San Diego, CA 92121 ("Lender") and
Randall E. Woods and Nancy Saint Woods, a married couple residing in the State
of California (collectively and separately "Borrower"), enter into this First
Amendment effective as of September 17, 1998.

                                  I. BACKGROUND
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      1.1     Randall E. Woods and Lender are parties to an Amended and Restated
Secured Promissory Note, having a date of August 28, 1997 ("Amended Note"),
which is appended hereto as Appendix I, and which relates, in part, to the grant
of a security interest in all of Mr. Woods' right, title and interest in the
Lawsuit (Case No. N075230).

      1.2     As approved by resolution of the Board of Directors of Lender
("Board") at its Board Meeting held October 6, 1998, Lender and Mr. Woods each
desires to amend and restate the Amended Note pursuant to the terms expressly
stated herein. More specifically, the parties wish to amend the Amended Note to
a) recognize that right, title and interest in the Lawsuit may be jointly owned
by Randall E. Woods and Nancy Saint Woods, pursuant to community property laws
of the State of California, b) recognize a change in identification of the
lawsuit, and c) recognize the Board's instruction that one aspect of the final
maturity date of the Note be extended.

      1.3     All capitalized terms not defined, or redefined via amendment, in
this First Amendment, are as defined in the Amended Note.

                     II. AMENDMENT TO DEFINITION OF BORROWER
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      2.1     Section A of the Amended Note defines "Borrower" to be Randall E.
Woods, an individual residing in the State of California.

      2.2     The definition of Borrower in the Amended Note is hereby amended
to be Randall E. Woods and Nancy Saint Woods, a married couple residing in the
State of California.

                    III. AMENDMENT TO LAWSUIT IDENTIFICATION
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      3.1     Section D of the Amended Note is hereby amended to delete "Case
No. N075230", and to state in its place "Case No. N0724356".

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                         IV. AMENDMENT TO MATURITY DATE
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      4.1     A new Section F is added to the Amended Note, immediately
following Section E:

              F.     As approved by resolution of the Board of Directors of
Lender at its Board meeting held October 6, 1998, Borrower and Lender each
desires to amend and restate in its entirety the Amended Note to provide that
the final maturity date of the Note, as defined therein, is extended to the
earliest of (i) August 28, 1999, (ii) the settlement or other final
determination of the Lawsuit and (iii) the date which is ninety days after any
termination of employment of Mr. Woods with Lender for any reason or no reason
(with or without cause) and (b) to provide for the grant of a security interest
in all of Borrower's right, title and interest in the Lawsuit and the proceeds
thereof to secure the repayment of principal under this Note and the payment of
all costs incurred by Lender pursuant to the enforcement of Lender's rights
under this Note and the performance of all other obligations under this Note by
Borrower.

      4.2     Section 1 of the Amended Note is hereby amended to a) delete
"September 18, 1998", and to state in its place "August 28, 1999", and b) to
delete "Borrower", and to state in its place "Mr. Woods".

                            V. ADDITIONAL AMENDMENTS
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      5.1     Section 3 of the Amended Note is hereby amended to delete the
first sentence of Section 3 in its entirety, and to state in its place:

              "In order to secure the prompt and complete payment and
              performance of all obligations of borrower under this Note,
              including, without limitation, the repayment of principal and the
              reimbursement of all costs of enforcing any of Lender's rights
              under this Note (including, without limitation, reasonable
              attorneys' fees, disbursements, costs and other expenses),
              Borrower hereby grants to Lender a security interest in all of
              Borrower's right, title and interest in the lawsuit filed by
              Borrower in the Superior Court of the State of California for the
              County of San Diego, North County Judicial District, known as Case
              No. N0724356 and the proceeds thereof (the "Collateral").

      5.2     Pursuant to Section 3, a UCC-1 Financing Statement has been
executed by Borrower, and is attached hereto as Appendix II.

      5.3     Section 4 of the Amended Note, item (3), is hereby amended to
delete "Borrower" and to state in its place "both Borrowers".


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      Other than expressly amended and stated herein, no other aspect of the
Amended Note is altered by this First Amendment. Agreement to the foregoing is
acknowledged by the signatures below:


/s/ RANDALL E. WOODS                NOVEMBER 10, 1998
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Randall E. Woods                    Date


/s/ NANCY SAINT WOODS               NOVEMBER 10, 1998
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Nancy Saint Woods                   Date