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                 AMENDED AND RESTATED SECURED PROMISSORY NOTE


$152,500                                                     August 28, 1997


    A.   Randall E. Woods, an individual residing in the State of California 
("Borrower"), has executed that certain Promissory Note dated June 25, 1996 
(the "Original  Note") in an original principal amount of $200,000 in favor 
of Corvas International, Inc., a Delaware corporation ("Lender"), evidencing 
a loan made by Lender to Borrower in connection with the relocation of 
Borrower to San Diego, California. Payment and performance in respect of the 
Original Note was to be secured by that certain unrecorded Deed of Trust 
dated June 25, 1996 (the "Deed of Trust") to encumber certain real property 
located in Potomac, Maryland (the "Property") formerly owned by Borrower.

    B.   On January 30, 1997, Lender executed that certain Extension of 
Promissory Note pursuant to which the final maturity date of the Original 
Note was extended from December 7, 1996 to the earlier of the sale of the 
Property or December 7, 1997.

    C.   On May 1, 1997, Lender agreed to pay to Borrower the difference 
between the purchase price originally paid by Borrower for the Property and 
the sales price when the Property actually sold, not to exceed $47,500.  On 
August 28, 1997, Borrower sold the Property and applied the $47,500 against 
the outstanding principal amount owing under the Original Note.  The current 
principal balance outstanding under the Original Note is $152,500.

    D.   Borrower has filed various claims against various defendants in the 
Superior Court of the State of California for the County of San Diego, North 
County Judicial District, (Case No. N075230) in connection with certain 
alleged defects and other matters related to certain real property owned by 
Borrower in the County of San Diego, State of California (the "Lawsuit").

    E.   As  approved by resolution of the Board of Directors of Lender at 
its Board meeting held September 18, 1997, Borrower and Lender each desires 
to amend and restate in its entirety the Original Note pursuant to this 
Amended and Restated Secured Promissory Note (the "Note") to (a) extend the 
final maturity date to the earliest of (i) September 18, 1998, (ii) the 
settlement or other final determination of the Lawsuit and (iii) the date 
which is ninety days after any termination of employment of Borrower 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.

For Value Received, Borrower, under the terms of this Note, hereby 
unconditionally promises to pay to Lender in lawful money of the United 
States of America and in immediately available funds, the principal sum of 
One Hundred Fifty-Two Thousand Five Hundred and 00/100 Dollars ($152,500) 
(the "Loan"), payable on the dates, in the amounts and in the manner set 
forth below.

    1.   REPAYMENT; PREPAYMENT.  The outstanding principal amount of the Loan 
shall be due and payable on the earliest of (i) September 18, 1998 (ii) the 
settlement or other final determination of the Lawsuit and (iii) the date 
which is ninety days after any

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termination of employment of Borrower with Lender for any reason or no reason 
(with or  without cause).  The Loan may be prepaid at any time without 
penalty. Amounts so prepaid shall not be re-borrowed.

    2.   APPLICATION OF PAYMENTS/PLACE OF PAYMENT.  All payments received by 
Lender shall be applied first to any charges due with respect to this Note or 
any other document executed by Borrower in connection herewith and second to 
the unpaid principal balance.  All amounts payable hereunder  shall be 
payable at the office of Lender, 3030 Science Park Road, San Diego, 
California 92121, unless another place of payment shall be specified in 
writing by Lender to Borrower.  Any  amounts payable hereunder  will be due 
and payable without set-off, deduction, or counterclaim, except as otherwise 
provided herein.

    3.   SECURED NOTE.  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 and 
Nancy Saint Woods, an individual, in the Superior Court of the State of 
California for the County of San Diego, North County Judicial District, known 
as Case No. N075230 and the proceeds thereof (the "Collateral").  Borrower 
hereby agrees to execute a UCC-1 Financing Statement in the form attached 
hereto as Exhibit "A", and from time to time to execute any and all other 
documents reasonably requested by Lender to perfect Lender's security 
interest in the Collateral.  Upon the repayment in full of all obligations 
under this Note, Lender hereby agrees to execute all documents and exercise 
such further actions as necessary to release the security interest in the 
Collateral  and to terminate any and all UCC financing statements or similar 
filings then effective with respect to the Collateral.  If an Event of 
Default has occurred and is continuing, Lender shall have all of the rights 
and remedies with respect to the Collateral of a secured creditor under the 
Uniform Commercial Code as  in effect in the State of California.

    4.   DEFAULT.  An Event of Default under this Note shall  have occurred 
upon the occurrence  of any one or more the following events: (1) the 
Borrower's failure to pay any of the principal due under this Note when the 
same becomes due and payable or the Borrower's failure to pay any other 
amounts payable under this Note on the date the same become due and payable 
or within five (5) calendar days thereafter, (2) the filing by Borrower of a 
petition under the United States Bankruptcy Code or (3) the death of Borrower 
or any other maker, endorser, guarantor of this Note.  Upon the occurrence of 
an Event of Default, all unpaid principal and any other amounts owing 
hereunder shall, at the option of Lender, be immediately  collectible  by 
Lender pursuant  to applicable law, and Lender may exercise any and all 
remedies of a secured creditor under the UCC.

    5.   WAIVER.  Borrower, and any endorsers or guarantors hereof, each 
severally waives diligence, presentment, protest and demand  and also notice 
of protest, demand, dishonor, acceleration, intent to accelerate and 
nonpayment of this Note, and expressly agrees that this Note, or any payment 
hereunder, may be extended from time to time without notice, and consent to 
the acceptance of further security or the release of any security for this 
Note, all without in any way affecting the liability of Borrower or any 
endorsers or guarantors hereof.  No extension of time for the payment  of 
this Note, or any installment hereof, agreed to by Lender with any person now 
or hereafter liable for the payment of this Note, shall affect the original 
liability of Borrower under this Note, even if Borrower is not party to such 
an agreement or indulgence. Borrower shall pay all costs of

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collection when incurred, including, without limitation, reasonable 
attorneys' fees, disbursements, costs and other expenses.

         The right to plead any and all statutes of limitations as a defense 
to any demands  hereunder is hereby  waived to the full extent permitted by 
law.

    6.   GOVERNING LAW.  This Note shall be governed by, and construed and 
enforced in accordance with, the laws of the State of California, excluding 
conflict of laws principles that would cause the application of laws of any 
other jurisdiction.

    7.   SUCCESSORS.  The  provisions of this Note shall inure to the benefit 
of and be binding on any successor or assign to Borrower or Lender.  This 
Note shall not be assigned by Borrower without the prior written consent of 
Lender.

    8.   MISCELLANEOUS.

         a.   Borrower shall pay all costs, including, without limitation, 
reasonable  attorneys' fees incurred by  Lender in collecting the  sums due 
hereunder or  in connection  with the release of the security for this Note.

         b.   This Note may be modified only by a written agreement executed 
by Borrower and Lender.

         c.   Time is of the essence with respect to all matters set forth in 
this Note.

         d.   If this Note is destroyed, lost or stolen, Borrower shall 
deliver a new note to Lender on the same terms and conditions as this Note 
with a notation of the unpaid principal in substitution of the prior Note.  
Lender shall furnish to Borrower reasonable evidence that the Note was 
destroyed, lost or stolen and any security or indemnity that may be 
reasonably required by Borrower in connection with the replacement of this 
Note.

         e.   If any provision of this Note shall be held to be invalid and 
unenforceable, such determination shall not affect the remaining provisions 
of this Note.

         f.   In the event an action is commenced  to interpret or enforce 
this Note or to collect any sums due hereunder, the prevailing party shall be 
entitled to receive from the other party attorneys' fees, disbursements,  
costs and other expenses determined by the court in which such action is 
brought.

         g.   This Amended and Restated Secured Promissory Note is not 
intended to be, and shall not be construed to create, a novation or accord 
and satisfaction, and, except as otherwise provided herein, the terms of the 
Original  Note, as extended prior to the execution hereof, shall remain in 
full force and effect.

                                       /s/ RANDALL E. WOODS
                                       ----------------------------
                                       Randall E. Woods, Borrower