<PAGE>
EXHIBIT 3.6

                      RESTATED CERTIFICATE OF INCORPORATION
                                       OF
                           CORVAS INTERNATIONAL, INC.


         Randall E. Woods and Kevin S. Helmbacher hereby certify that:

         ONE: The original name of this corporation is Corvas International,
Inc. and the date of filing the original Certificate of Incorporation of this
corporation with the Secretary of State of the State of Delaware is May 11,
1993.

         TWO: They are the duly elected and acting President and Secretary,
respectively, of Corvas International, Inc., a Delaware corporation.

         THREE: The Certificate of Incorporation of this corporation is hereby
amended and restated to read as follows:

                                       I.

         The name of this corporation is Corvas International, Inc.

                                      II.

         The address of the registered office of the corporation in the State of
Delaware is 32 Loockerman Square, Suite L-100, City of Dover, County of Kent,
and the name of the registered agent of the corporation in the State of Delaware
at such address is The Prentice-Hall Corporation System, Inc.

                                      III.

         The purpose of this corporation is to engage in any lawful act or
activity for which a corporation may be organized under the General Corporation
Law of the State of Delaware.

                                      IV.

         A. This corporation is authorized to issue two classes of stock
designated respectively, "Common Stock" and "Preferred Stock." The total number
of shares which the corporation is authorized to issue is eighty-five million
(85,000,000) shares, consisting of seventy-five million (75,000,000) shares of
Common Stock, each having a par value of one-tenth of one cent ($.001), and ten
million (10,000,000) shares of Preferred Stock, each having a par value of one
tenth of one cent ($.001).

         B. The Preferred Stock may be issued from time to time in one or more
series. The Board of Directors is hereby authorized, by filing a certificate (a
"Preferred Stock Designation") pursuant to the Delaware General Corporation Law,
to fix or alter from time to time the designation, powers, preferences and
rights of the shares of each such series and the qualifications, limitations or
restrictions of any wholly unissued series of Preferred Stock, and to establish
from time to time the number of shares constituting any such series or any of

                                       1.
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them; and to increase or decrease the number of shares of any series subsequent
to the issuance of shares of that series, but not below the number of shares of
such series then outstanding. In case the number of shares of any series shall
be decreased in accordance with the foregoing sentence, the shares constituting
such decrease shall resume the status that they had prior to the adoption of the
resolution originally fixing the number of shares of such series.

         C. DESIGNATION AND AMOUNT. Seven Hundred Fifty Thousand (750,000)
shares of Preferred Stock, $.001 par value, are designated "Series C Junior
Participating Preferred Stock" with the designations and the powers, preferences
and rights, and the qualifications, limitations and restrictions specified
herein (the "Series C Preferred"). Such number of shares may be increased or
decreased by resolution of the Board of Directors; provided, that no decrease
shall reduce the number of shares of Series C Preferred to a number less than
the number of shares then outstanding plus the number of shares reserved for
issuance upon the exercise of outstanding options, rights or warrants or upon
the conversion of any outstanding securities issued by the Company convertible
into Series C Preferred.

            (1) DIVIDENDS AND DISTRIBUTIONS.

                  (i) Subject to the payment in full of all accrued dividends to
the holders of any shares of any other series of Preferred Stock (or any similar
stock) ranking prior and superior to the Series C Preferred with respect to
dividends, the holders of shares of Series C Preferred, in preference to the
holders of Common Stock, par value $.001 per share (the "Common Stock"), of the
Company (preferential to the Common Stock), and of any other junior stock, shall
be entitled to receive, when, as and if declared by the Board of Directors out
of funds legally available for the purpose, quarterly dividends payable in cash
on the first day of April, July, October and January in each year (each such
date being referred to herein as a "Quarterly Dividend Payment Date"),
commencing on the first Quarterly Dividend Payment Date after the first issuance
of a share or fraction of a share of Series C Preferred, in an amount per share
(rounded to the nearest cent) equal to the greater of (a) $l.00 or (b) subject
to the provision for adjustment hereinafter set forth, 100 times the aggregate
per share amount of all cash dividends, and 100 times the aggregate per share
amount (payable in kind) of all non-cash dividends or other distributions, other
than a dividend payable in shares of Common Stock or a subdivision of the
outstanding shares of Common Stock (by reclassification or otherwise), declared
on the Common Stock since the immediately preceding Quarterly Dividend Payment
Date or, with respect to the first Quarterly Dividend Payment Date, since the
first issuance of any share or fraction of a share of Series C Preferred. In the
event the Company shall at any time declare or pay any dividend on the Common
Stock payable in shares of Common Stock, or effect a subdivision or combination
or consolidation of the outstanding shares of Common Stock (by reclassification
or otherwise than by payment of a dividend in shares of Common Stock) into a
greater or lesser number of shares of Common Stock, then in each such case the
amount to which holders of shares of Series C Preferred were entitled
immediately prior to such event under clause (b) of the preceding sentence shall
be adjusted by multiplying such amount by a fraction, the numerator of which is
the number of shares of Common Stock outstanding immediately after such event
and the denominator of which is the number of shares of Common Stock that were
outstanding immediately prior to such event.

                                       2.
<PAGE>

                  (ii) The Company shall declare a dividend or distribution on
the Series C Preferred as provided in paragraph (A) of this Section immediately
after it declares a dividend or distribution on the Common Stock (other than a
dividend payable in shares of Common Stock); provided that, in the event no
dividend or distribution shall have been declared on the Common Stock during the
period between any Quarterly Dividend Payment Date and the next subsequent
Quarterly Dividend Payment Date, a dividend of $1.00 per share on the Series C
Preferred shall nevertheless be payable on such subsequent Quarterly Dividend
Payment Date.

                  (iii) Dividends shall begin to accrue and be cumulative on
outstanding shares of Series C Preferred from the Quarterly Dividend Payment
Date next preceding the date of issue of such shares, unless the date of issue
of such shares is prior to the record date for the first Quarterly Dividend
Payment Date, in which case dividends on such shares shall begin to accrue from
the date of issue of such shares, or unless the date of issue is a Quarterly
Dividend Payment Date or is a date after the record date for the determination
of holders of shares of Series C Preferred entitled to receive a quarterly
dividend and before such Quarterly Dividend Payment Date, in either of which
events such dividends shall begin to accrue and be cumulative from such
Quarterly Dividend Payment Date. Accrued but unpaid dividends shall not bear
interest. Dividends paid on the shares of Series C Preferred in an amount less
than the total amount of such dividends at the time accrued and payable on such
shares shall be allocated pro rata on a share-by-share basis among all such
shares at the time outstanding. The Board of Directors may fix a record date for
the determination of holders of shares of Series C Preferred entitled to receive
payment of a dividend or distribution declared thereon, which record date shall
be not more than 60 days prior to the date fixed for the payment thereof.

            (2) VOTING RIGHTS. The holders of shares of Series C Preferred
shall have the following voting rights:

                  (i) Subject to the provision for adjustment hereinafter set
forth, each share of Series C Preferred shall entitle the holder thereof to 100
votes on all matters submitted to a vote of the stockholders of the Company. In
the event the Company shall at any time declare or pay any dividend on the
Common Stock payable in shares of Common Stock, or effect a subdivision or
combination or consolidation of the outstanding shares of Common Stock (by
reclassification or otherwise than by payment of a dividend in shares of Common
Stock) into a greater or lesser number of shares of Common Stock, then in each
such case the number of votes per share to which holders of shares of Series C
Preferred were entitled immediately prior to such event shall be adjusted by
multiplying such number by a fraction, the numerator of which is the number of
shares of Common Stock outstanding immediately after such event and the
denominator of which is the number of shares of Common Stock that were
outstanding immediately prior to such event.

                  (ii) Except as otherwise provided herein, in any other
Certificate of Designations creating a series of Preferred Stock or any similar
stock, or by law, the Series C Preferred shall be voted equally with the shares
of the Common Stock and any other capital stock of the Company having general
voting rights as one class on all matters submitted to a vote of stockholders of
the Company.

                                       3.
<PAGE>

                  (iii) Except as set forth herein, or as otherwise provided by
law, holders of Series C Preferred shall have no special voting rights and their
consent shall not be required (except to the extent they are entitled to vote
with holders of the Common Stock as set forth herein) for taking any corporate
action.

            (3) CERTAIN RESTRICTIONS.

                  (i) Whenever quarterly dividends or other dividends or
distributions payable on the Series C Preferred as provided in Section 2 are in
arrears, thereafter and until all accrued and unpaid dividends and
distributions, whether or not declared, on shares of Series C Preferred
outstanding shall have been paid in full, the Company shall not:

                         (a) declare or pay dividends, or make any other
distributions, on any shares of stock ranking junior (either as to dividends or
upon liquidation, dissolution or winding up) to the Series C Preferred;

                         (b) declare or pay dividends, or make any other
distributions, on any shares of stock ranking on a parity (either as to
dividends or upon liquidation, dissolution or winding up) with the Series C
Preferred, except dividends paid ratably on the Series C Preferred and all such
parity stock on which dividends are payable or in arrears in proportion to the
total amounts to which the holders of all such shares are then entitled;

                         (c) redeem or purchase or otherwise acquire for
consideration shares of any stock ranking junior (either as to dividends or upon
liquidation, dissolution or winding up) to the Series C Preferred, provided that
the Company may at any time redeem, purchase or otherwise acquire shares of any
such junior stock in exchange for shares of any stock of the Company ranking
junior (either as to dividends or upon dissolution, liquidation or winding up)
to the Series C Preferred; or

                         (d) redeem or purchase or otherwise acquire for
consideration any shares of Series C Preferred, or any shares of stock ranking
on a parity (either as to dividends or upon liquidation, dissolution or winding
up) with the Series C Preferred, except in accordance with a purchase offer made
in writing or by publication (as determined by the Board of Directors) to all
holders of such shares upon such terms as the Board of Directors, after
consideration of the respective annual dividend rates and other relative rights
and preferences of the respective series and classes, shall determine in good
faith will result in fair and equitable treatment among the respective series or
classes.

                  (ii) The Company shall not permit any subsidiary of the
Company to purchase or otherwise acquire for consideration any shares of stock
of the Company unless the Company could, under paragraph (A) of this Section 4,
purchase or otherwise acquire such shares at such time and in such manner.

            (4) REACQUIRED SHARES. Any shares of Series C Preferred purchased or
otherwise acquired by the Company in any manner whatsoever shall be retired and
canceled promptly after the acquisition thereof. All such shares shall upon
their cancellation become authorized but unissued shares of Preferred Stock and
may be reissued as part of a new series of Preferred Stock subject to the
conditions and restrictions on issuance set forth herein, in the Restated

                                       4.
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Certificate of Incorporation or in any other Certificate of Designations
creating a series of Preferred Stock or any similar stock or as otherwise
required by law.

            (5) LIQUIDATION, DISSOLUTION OR WINDING UP. Subject to the payment
in full of the liquidation preferences of any shares of any series of Preferred
Stock (or any similar stock) ranking prior and superior to the Series C
Preferred with respect to the distribution of assets, upon any liquidation,
dissolution or winding up of the Company, no distribution shall be made (1) to
the holders of shares of stock ranking junior (either as to dividends or upon
liquidation, dissolution or winding up) to the Series C Preferred unless, prior
thereto, the holders of shares of Series C Preferred shall have received $100
per share, plus an amount equal to accrued and unpaid dividends and
distributions thereon, whether or not declared, to the date of such payment,
provided that the holders of shares of Series C Preferred shall be entitled to
receive an aggregate amount per share, subject to the provision for adjustment
hereinafter set forth, equal to 100 times the aggregate amount to be distributed
per share to holders of shares of Common Stock, or (2) to the holders of shares
of stock ranking on a parity (either as to dividends or upon liquidation,
dissolution or winding up) with the Series C Preferred, except distributions
made ratably on the Series C Preferred and all such parity stock in proportion
to the total amounts to which the holders of all such shares are entitled upon
such liquidation, dissolution or winding up. In the event the Company shall at
any time declare or pay any dividend on the Common Stock payable in shares of
Common Stock, or effect a subdivision or combination or consolidation of the
outstanding shares of Common Stock (by reclassification or otherwise than by
payment of a dividend in shares of Common Stock) into a greater or lesser number
of shares of Common Stock, then in each such case the aggregate amount to which
holders of shares of Series C Preferred were entitled immediately prior to such
event under the proviso in clause (1) of the preceding sentence shall be
adjusted by multiplying such amount by a fraction the numerator of which is the
number of shares of Common Stock outstanding immediately after such event and
the denominator of which is the number of shares of Common Stock that were
outstanding immediately prior to such event.

            (6) CONSOLIDATION, MERGER, ETC. In case the Company shall enter into
any consolidation, merger, combination or other transaction in which the shares
of Common Stock are exchanged for or changed into other stock or securities,
cash and/or any other property, then in any such case each share of Series C
Preferred shall at the same time be similarly exchanged or changed into an
amount per share, subject to the provision for adjustment hereinafter set forth,
equal to 100 times the aggregate amount of stock, securities, cash and/or any
other property (payable in kind), as the case may be, into which or for which
each share of Common Stock is changed or exchanged. In the event the Company
shall at any time declare or pay any dividend on the Common Stock payable in
shares of Common Stock, or effect a subdivision or combination or consolidation
of the outstanding shares of Common Stock (by reclassification or otherwise than
by payment of a dividend in shares of Common Stock) into a greater or lesser
number of shares of Common Stock, then in each such case the amount set forth in
the preceding sentence with respect to the exchange or change of shares of
Series C Preferred shall be adjusted by multiplying such amount by a fraction,
the numerator of which is the number of shares of Common Stock outstanding
immediately after such event and the denominator of which is the number of
shares of Common Stock that were outstanding immediately prior to such event.


                                       5.
<PAGE>

            (7) NO REDEMPTION. The shares of Series C Preferred shall not be
redeemable.

            (8) RANK. The Series C Preferred shall rank, with respect to the
payment of dividends and the distribution of assets, junior to any class of the
Company's Preferred Stock.

            (9) AMENDMENT. The Restated Certificate of Incorporation of the
Company shall not be amended in any manner which would materially alter or
change the powers, preferences or special rights of the Series C Preferred so as
to affect them adversely without the affirmative vote of the holders of at least
two-thirds of the outstanding shares of Series C Preferred, voting together as a
single class.

                                       V.

         For the management of the business and for the conduct of the affairs
of the corporation, and in further definition, limitation and regulation of the
powers of the corporation, of its directors and of its stockholders or any class
thereof, as the case may be, it is further provided that:

         A. (1) The management of the business and the conduct of the affairs of
the corporation shall be vested in its Board of Directors. The number of
directors which shall constitute the whole Board of Directors shall be fixed (a)
by one or more resolutions adopted by the Board of Directors, or (b) by the
affirmative vote of the holders of at least sixty-six and two-thirds percent (66
2/3%) of the voting power of the then-outstanding shares of voting stock of the
corporation entitled to vote at an election of directors (the "Voting Stock").

            (2) Subject to the rights of the holders of any series of Preferred
Stock to elect additional directors under specified circumstances, the directors
shall be divided into three classes designated as Class I, Class II and Class
III, respectively. Directors shall be assigned to each class in accordance with
a resolution or resolutions adopted by the Board of Directors. At each annual
meeting of stockholders, directors shall be elected for a full term of three
years to succeed the directors of the class whose terms expire at such annual
meeting.

            Notwithstanding the foregoing provisions of this Article, each
director shall serve until his successor is duly elected and qualified or until
his death, resignation or removal. No decrease in the number of directors
constituting the Board of Directors shall shorten the term of any incumbent
director.

            (3) Subject to any limitations imposed by law, the Board of
Directors or any individual director may be removed from office at any time (i)
with cause by the affirmative vote of the holders of at least a majority of the
voting power of all of the then-outstanding shares of the Voting Stock; or (ii)
without cause by an affirmative vote of the holders of at least sixty-six and
two-thirds percent (66 2/3%) of the then-outstanding shares of the Voting Stock.

            (4) Subject to the rights of the holders of any series of Preferred
Stock, any vacancies on the Board of Directors resulting from death,
resignation, disqualification, removal or other causes, and any newly created
directorships resulting from any increase in the number of directors, shall,
unless the Board of Directors determines by resolution that any such vacancies

                                       6.
<PAGE>

or newly created directorships shall be filled by the stockholders, except as
otherwise provided by law, be filled only by the affirmative vote of a majority
of the directors then in office, even though less than a quorum of the Board of
Directors, and not by the stockholders. Any director elected in accordance with
the preceding sentence shall hold office for the remainder of the full term of
the director for which the vacancy was created or occurred and until such
director's successor shall have been elected and qualified.

         B. (1) Subject to paragraph (h) of Section 43 of the By-laws, the
By-laws may be altered or amended or new By-laws adopted by the affirmative vote
of sixty-six and two-thirds percent (66 2/3%) of the voting power of all of the
then-outstanding shares of the Voting Stock. The Board of Directors shall also
have the power to adopt, amend or repeal By-laws.

            (2) The directors of the corporation need not be elected by written
ballot unless the By-laws so provide.

            (3) No action shall be taken by the stockholders of the corporation
except at an annual or special meeting of stockholders called in accordance with
the By-laws and no action shall be taken by the stockholders by written consent.

            (4) Special meetings of the stockholders of the corporation may be
called, for any purpose or purposes, by (i) the Chairman of the Board of
Directors, (ii) the Chief Executive Officer, (iii) the Board of Directors
pursuant to a resolution adopted by a majority of the total number of authorized
directors (whether or not there exist any vacancies in previously authorized
directorships at the time any such resolution is presented to the Board of
Directors for adoption), or (iv) the holders of shares entitled to cast not less
than ten percent (10%) of the votes at the meeting, and shall be held at such
place, on such date and at such time as the Board of Directors shall fix.

            (5) Advance notice of stockholder nominations for the election of
directors and of business to be brought by stockholders before any meeting of
the stockholders of the corporation shall be given in the manner provided in the
By-laws of the corporation.

                                      VI.

         A. A director of the corporation shall not be personally liable to the
corporation or its stockholders for monetary damages for any breach of fiduciary
duty as a director, except for liability (i) for any breach of the director's
duty of loyalty to the corporation or its stockholders, (ii) for acts or
omissions not in good faith or which involve intentional misconduct or a knowing
violation of law (iii) under Section 174 of the Delaware General Corporation
Law, or (iv) for any transaction from which the director derived an improper
personal benefit. If the Delaware General Corporation Law is amended after
approval by the stockholders of this Article to authorize corporate action
further eliminating or limiting the personal liability of directors, then the
liability of a director shall be eliminated or limited to the fullest extent
permitted by the Delaware General Corporation Law, as so amended.

         B. Any repeal or modification of this Article VI shall be prospective
and shall not affect the rights under this Article VI in effect at the time of
the alleged occurrence of any act or omission to act giving rise to liability or
indemnification.


                                       7.
<PAGE>

                                      VII.

         A. (1) In addition to any affirmative vote required by law, by this
Restated Certificate of Incorporation or by any Preferred Stock Designation, and
except as otherwise expressly provided in Section B of this Article VII:

                  (i) any merger or consolidation of the corporation or any
Subsidiary (as hereinafter defined) with (a) any Interested Stockholder (as
hereinafter defined) or (b) any other corporation (whether or not itself an
Interested Stockholder) which is, or after such merger or consolidation would
be, an Affiliate (as hereinafter defined) of an Interested Stockholder, or

                  (ii) any sale, lease, exchange, mortgage, pledge, transfer or
other disposition (in one transaction or a series of transactions) to or with
any Interested Stockholder or any Affiliate of any Interested Stockholder of any
assets of the corporation or any Subsidiary having an aggregate Fair Market
Value (as hereinafter defined) equal to or greater than 15% of the corporation's
assets as set forth on the corporation's most recent audited consolidated
financial statements or

                  (iii) the issuance or transfer by the corporation or any
Subsidiary (in one transaction or a series of transactions) of any securities of
the corporation or any Subsidiary to any Interested Stockholder or any Affiliate
of any Interested Stockholder in exchange for cash, securities or other property
(or a combination thereof) having an aggregate Fair Market Value equal to or
greater than 15% of the corporation's assets as set forth on the corporation's
most recent audited consolidated financial statements; or

                  (iv) the adoption of any plan or proposal for the liquidation
or dissolution of the corporation proposed by or on behalf of any Interested
Stockholder or any Affiliate of any Interested Stockholder; or

                  (v) any reclassification of securities (including any reverse
stock split), or recapitalization of the corporation, or any merger or
consolidation of the corporation with any of its Subsidiaries or any other
transaction (whether or not with or into or otherwise involving any Interested
Stockholder) which has the effect, directly or indirectly, of increasing the
proportionate share of the outstanding shares of any class of equity or
convertible securities of the corporation or any Subsidiary which is
Beneficially Owned (as hereinafter defined) by any Interested Stockholder or any
Affiliate of any Interested Stockholder;

shall require the affirmative vote of the holders of at least sixty-six and
two-thirds percent (66 2/3%) of voting power of all the then-outstanding shares
of the Voting Stock, voting together as a single class. Such affirmative vote
shall be required notwithstanding any other provisions of this Restated
Certificate of Incorporation or any provision of law or of any agreement with
any national securities exchange or otherwise which might otherwise permit a
lesser vote or no vote.

            (2) The term "Business Combination" as used in this Article VII
shall mean any transaction which is referred to in any one or more of
subparagraphs (i) through (v) of paragraph (1) of this Section A.


                                       8.
<PAGE>

         B. The provisions of Section A of this Article VII shall not be
applicable to any particular Business Combination and such Business Combination
shall require only such affirmative vote as is required by law, any other
provision of this Restated Certificate of Incorporation and any Preferred Stock
Designation, if, in the case of a Business Combination that does not involve any
cash or other consideration being received by the stockholders of the
corporation, solely in their respective capacities as stockholders of the
corporation, the condition specified in the following paragraph (1) is met, or,
in the case of any other Business Combination, the conditions specified in
either of the following paragraph (1) or paragraph (2) are met:

            (1) The Business Combination shall have been approved by:

                  (i) a majority of the Continuing Directors (as hereinafter
defined); provided however, that this condition shall not be capable of
satisfaction unless there are at least two Continuing Directors; or

                  (ii) a majority of the shares not held by the Interested
Stockholder.

            (2) All of the following conditions shall have been met:

                  (i) The consideration to be received by holders of shares of a
particular class (or series) of outstanding Voting Stock (including Common Stock
and other than Excluded Preferred Stock (as hereinafter defined)) shall be in
cash or in the same form as the Interested Stockholder or any of its Affiliates
has previously paid for shares of such class (or series) of Voting Stock. If the
Interested Stockholder or any of its Affiliates have paid for shares of any
class (or series) of Voting Stock with varying forms of consideration, the form
of consideration to be received per share by holders of shares of such class (or
series) of Voting Stock shall be either cash or the form used to acquire the
largest number of shares of such class (or series) of Voting Stock previously
acquired by the Interested Stockholder.

                  (ii) The aggregate amount of (x) the cash and (y) the Fair
Market Value, as of the date (the "Consummation Date") of the consummation of
the Business Combination, of the consideration other than cash to be received
per share by holders of Common Stock in such Business Combination shall be at
least equal to the higher of the following (in each case appropriately adjusted
in the event of any stock dividend, stock split, combination of shares or
similar event):

                        (a) (if applicable) the highest per share price paid by
the Interested Stockholder or any of its Affiliates for any shares of Common
Stock acquired by them within the two-year period immediately prior to the date
of the first public announcement of the proposal of the Business Combination
(the "Announcement Date") or in any transaction in which the Interested
Stockholder became an Interested Stockholder, whichever is higher, and

                        (b) the Fair Market Value per share of Common Stock on
the Announcement Date or the first date on which the Interested Stockholder
became an Interested Stockholder (the "Determination Date") (which, if more than
two years prior to the Announcement Date shall be deemed to be the date two
years prior to the Announcement Date), whichever is higher.


                                       9.
<PAGE>

                  (iii) The aggregate amount of (x) the cash and (y) the Fair
Market Value, as of the Consummation Date, of the consideration other than cash
to be received per share by holders of shares of any class (or series), other
than Common Stock or Excluded Preferred Stock, of outstanding Voting Stock shall
be at least equal to the higher of the following (in each case appropriately
adjusted in the event of any stock dividend, stock split, combination of shares
or similar event), it being intended that the requirements of this paragraph
2(iii) shall be required to be met with respect to every such class (or series)
of outstanding Voting Stock whether or not the Interested Stockholder or any of
its Affiliates has previously acquired any shares of a particular class (or
series) of Voting Stock):

                        (a) (if applicable) the highest per share price paid by
the Interested Stockholder or any of its Affiliates for any shares of such class
(or series) of Voting Stock acquired by them within the two-year period
immediately prior to the Announcement Date or in any transaction in which it
became an Interested Stockholder, whichever is higher; and

                        (b) the Fair Market Value per share of such class (or
series) of Voting Stock on the Announcement Date or on the Determination Date,
whichever is higher.

                  (iv) After such Interested Stockholder has become an
Interested Stockholder and prior to the consummation of such Business
Combination: (a) except as approved by a majority of the Continuing Directors,
there shall have been no failure to declare and pay at the regular date therefor
any full quarterly dividends (whether or not cumulative) on any outstanding
Preferred Stock; (b) there shall have been (I) no reduction in the annual rate
of dividends paid on the Common Stock (except as necessary to reflect any
subdivision of the Common Stock), except as approved by a majority of the
Continuing Directors, and (II) an increase in such annual rate of dividends as
necessary to reflect any reclassification (including any reverse stock split),
recapitalization, reorganization or any similar transaction which has the effect
of reducing the number of outstanding shares of the Common Stock, unless the
failure so to increase such annual rate is approved by a majority of the
Continuing Directors; and (c) neither such Interested Stockholder nor any of its
Affiliates shall have become the beneficial owner of any additional shares of
Voting Stock except as part of the transaction which results in such Interested
Stockholder becoming an Interested Stockholder.

                  (v) After such Interested Stockholder has become an Interested
Stockholder, such Interested Stockholder and any of its Affiliates shall not
have received the benefit, directly or indirectly (except proportionately,
solely in such Interested Stockholder's or Affiliate's capacity as a stockholder
of the corporation), of any loans, advances, guarantees, pledges or other
financial assistance or any tax credits or other tax advantages provided by the
corporation, whether in anticipation of or in connection with such Business
Combination or otherwise.

                  (vi) A proxy or information statement describing the proposed
Business Combination and complying with the requirements of the Securities
Exchange Act of 1934, as amended, and the rules and regulations thereunder (or
any subsequent provisions replacing such Act, rules or regulations) shall be
mailed to all stockholders of the corporation at least 30 days prior to the
consummation of such Business Combination (whether or not such proxy or

                                      10.
<PAGE>

information statement is required to be mailed pursuant to such Act or
subsequent provisions).

                  (vii) Such Interested Stockholder shall have supplied the
corporation with such information as shall have been requested pursuant to
Section E of this Article VII within the time period set forth therein.

         C. For the purposes of this Article VII:

            (1) A "person" means any individual, limited partnership, general
partnership, corporation or other firm or entity.

            (2) "Interested Stockholder" means any person (other than the
corporation or any Subsidiary) who or which:

                  (i) is the Beneficial Owner (as hereinafter defined), directly
or indirectly, of fifteen percent (15%) or more of the voting power of all of
the then-outstanding shares of the Voting Stock, or

                  (ii) is an Affiliate of the corporation and at any time within
the two-year period immediately prior to the date in question was the Beneficial
Owner, directly or indirectly, of fifteen percent (15%) or more of the voting
power of all of the then-outstanding shares of the Voting Stock, or

                  (iii) is an assignee or has otherwise succeeded to any shares
of Voting Stock which were at any time within the two-year period immediately
prior to the date in question beneficially owned by an Interested Stockholder,
if such assignment or succession shall have occurred in the course of a
transaction or series of transactions not involving a public offering within the
meaning of the 1933 Act.

            (3) A person shall be a "Beneficial Owner" of, or shall
"Beneficially Own," any Voting Stock:

                  (i) which such person or any of its Affiliates or Associates
(as hereinafter defined) beneficially owns, directly or indirectly within the
meaning of Rule l3d-3 under the Securities Exchange Act of 1934, as in effect on
May 11, 1993; or

                  (ii) which such person or any of its Affiliates or Associates
has (a) the right to acquire (whether such right is exercisable immediately or
only after the passage of time), pursuant to any agreement, arrangement or
understanding or upon the exercise of conversion rights, exchange rights,
warrants or options, or otherwise, or (b) the right to vote pursuant to any
agreement, arrangement or understanding (but shall not be deemed to be the
Beneficial Owner of any shares of Voting Stock solely by reason of a revocable
proxy granted for a particular meeting of stockholders, pursuant to a public
solicitation of proxies for such meeting, and with respect to which shares
neither such person nor any such Affiliate or Associate is otherwise deemed the
Beneficial Owner); or


                                      11.
<PAGE>

                  (iii) which is beneficially owned, directly or indirectly,
within the meaning of Rule 13d-3 under the Securities Exchange Act of 1934, as
in effect on May 11, 1993, by any other person with which such person or any of
its Affiliates or Associates has any agreement, arrangement or understanding for
the purpose of acquiring, holding, voting (other than solely by reason of a
revocable proxy as described in subparagraph (ii) of this paragraph (3)) or
disposing of any shares of Voting Stock;

provided, however, that in case of any employee stock ownership or similar plan
of the corporation or of any Subsidiary in which the beneficiaries thereof
possess the right to vote any shares of Voting Stock held by such plan, no such
plan nor any trustee with respect thereto (nor any Affiliate of such trustee),
solely by reason of such capacity of such trustee, shall be deemed, for any
purposes hereof, to beneficially own any shares of Voting Stock held under any
such plan.

            (4) For the purposes of determining whether a person is an
Interested Stockholder pursuant to paragraph (2) of this Section C, the number
of shares of Voting Stock deemed to be outstanding shall include shares deemed
owned through application of paragraph (3) of this Section C but shall not
include any other unissued shares of Voting Stock which may be issuable pursuant
to any agreement, arrangement or understanding, or upon exercise of conversion
rights, warrants or options, or otherwise.

            (5) "Affiliate" or "Associate" shall have the respective meanings
ascribed to such terms in Rule l2b-2 of the General Rules and Regulations under
the Securities Exchange Act of 1934, as in effect on May 11, 1993.

            (6) "Subsidiary" means any corporation of which a majority of any
class of equity security is owned, directly or indirectly, by the corporation;
provided, however, that for the purposes of the definition of Interested
Stockholder set forth in paragraph (2) of this Section C, the term "Subsidiary"
shall mean only a corporation of which a majority of each class of equity
security is owned directly or indirectly, by the corporation.

            (7) "Continuing Director" means any member of the Board of Directors
of the corporation who is a director originally elected or appointed upon
incorporation of the corporation or who is not an Interested Stockholder or
affiliated with the Interested Stockholder and was a member of the Board of
Directors prior to the time that the Interested Stockholder became an Interested
Stockholder and any director who is thereafter chosen to fill any vacancy on the
Board of Directors or who is elected and who, in either event, is not an
Interested Stockholder or unaffiliated with the Interested Stockholder and in
connection with his or her initial assumption of office is recommended for an
appointment or election by a majority of Continuing Directors then on the Board.

            (8) "Fair Market Value" means: (i) in the case of stock, the highest
closing sale price on the last trading day immediately preceding the date in
question of a share of such stock on the Composite Tape for New York Stock
Exchange-Listed Stocks, or, if such stock is not quoted on the Composite Tape,
on the New York Stock Exchange, or, if such stock is not listed on such

                                      12.
<PAGE>

Exchange, on the principal United States securities exchange registered under
the Securities Exchange Act of 1934 on which such stock is listed, or, if such
stock is not listed on any such exchange, the highest closing sale price
quotation with respect to a share of such stock on the last trading day
preceding the date in question on the National Association of Securities
Dealers, Inc. Automated Quotations System or any system then in use, or if no
such quotations are available, the fair market value on the date in question of
a share of such stock as determined by the Board in accordance with Section D of
this Article VII; and (ii) in the case of property other than cash or stock, the
fair market value of such property on the date in question as determined by the
Board in accordance with Section D of this Article VII.

            (9) In the event of any Business Combination in which the
corporation survives, the phrase "consideration other than cash to be received"
as used in paragraphs (2)(ii) and (2)(iii) of Section B of this Article VII
shall include the shares of Common Stock and/or the shares of any other class
(or series) of outstanding Voting Stock retained by the holders of such shares.

            (10) "Whole Board" means the total number of directors which this
corporation would have if there were no vacancies.

            (11) "Excluded Preferred Stock" means any series of Preferred Stock
with respect to which the Preferred Stock Designation creating such series
expressly provides that the provisions of this Article VII shall not apply.

         D. A majority of the Whole Board but only if a majority of the Whole
Board shall then consist of Continuing Directors or, if a majority of the Whole
Board shall not then consist of Continuing Directors, a majority of the then
Continuing Directors, shall have the power and duty to determine, on the basis
of information known to them after reasonable inquiry, all facts necessary to
determine compliance with this Article, including, without limitation, (i)
whether a person is an Interested Stockholder, (ii) the number of shares of
Voting Stock beneficially owned by any person (iii) whether a person is an
Affiliate or Associate of another, (iv) whether the applicable conditions set
forth in paragraph (2) of Section B have been met with respect to any Business
Combination, (v) the Fair Market Value of stock or other property in accordance
with paragraph (8) of Section C of this Article VII, and (vi) whether the assets
which are the subject of any Business Combination referred to in paragraph
(1)(ii) of Section A have or the consideration to be received for the issuance
or transfer of securities by the corporation or any Subsidiary in any Business
Combination referred to in paragraph (1)(iii) of Section A has, an aggregate
Fair Market Value equal to or greater than 15% of the corporation's assets as
set forth on the corporation's most recent audited consolidated financial
statements.

         E. A majority of the Whole Board shall have the right to demand, but
only if a majority of the Whole Board shall then consist of Continuing
Directors, or, if a majority of the Whole Board shall not then consist of
Continuing Directors, a majority of the then Continuing Directors shall have the
right to demand, that any person who it is reasonably believed is an Interested
Stockholder (or holds of record shares of Voting Stock Beneficially Owned by any
Interested Stockholder) supply this corporation with complete information as to
(i) the record owner(s) of all shares Beneficially Owned by such person who it
is reasonably believed is an Interested Stockholder, (ii) the number of, and
class or series of, shares Beneficially Owned by such person who it is
reasonably believed is an Interested Stockholder and held of record by each such
record owner and the number(s) of the stock certificate(s) evidencing such
shares, and (iii) any other factual matter relating to the applicability of


                                      13.
<PAGE>

effect of this Article VII, as may be reasonably requested of such person, and
such person shall furnish such information within 10 days after receipt of such
demand.

         F. Nothing contained in this Article VII shall be construed to relieve
any Interested Stockholder from any fiduciary obligation imposed by law.

                                     VIII.

         A. The corporation reserves the right to amend, alter, change or repeal
any provision contained in this Restated Certificate of Incorporation, in the
manner now or hereafter prescribed by statute, except as provided in paragraph B
of this Article VIII, and all right conferred upon the stockholders herein are
granted subject to this reservation.

         B. Notwithstanding any other provisions of this Restated Certificate of
Incorporation or any provision of law which might otherwise permit a lesser vote
or no vote, but in addition to any affirmative vote of the holders of any
particular class or series of the Voting Stock required by law, this Restated
Certificate of Incorporation or any Preferred Stock Designation, the affirmative
vote of the holders of at least sixty-six and two-thirds percent (66 2/3%) of
the voting power of all of the then-outstanding shares of the Voting Stock,
voting together as a single class, shall be required to alter, amend or repeal
Article V, VI, VII or VIII.

                                     * * * *

         FOUR: This Restated Certificate of Incorporation has been duly approved
by the Board of Directors of this Corporation.

         FIVE: This Restated Certificate of Incorporation has been duly adopted
in accordance with the provisions of Sections 228 and 245 of the General
Corporation Law of the State of Delaware by the Board of Directors and the
stockholders of the Corporation. The total number of outstanding shares entitled
to vote or act by written consent was 27,364,171 shares of Common Stock. A
majority of the outstanding shares of Common Stock, voting together as a single
class, voted in favor of this Restated Certificate of Incorporation. The vote
required was a majority of the outstanding shares of Common Stock, voting
together as a single class.





                                      14.
<PAGE>


         IN WITNESS WHEREOF, Corvas International, Inc. has caused this Restated
Certificate of Incorporation to be signed by the President and the Secretary in
San Diego, California this 6th day of June 2001.



                                               CORVAS INTERNATIONAL, INC.

                                               By:  /s/ RANDALL E. WOODS
                                                    --------------------
                                                    Randall E. Woods
                                                    President and CEO



ATTEST:

By:  /s/ KEVIN S. HELMBACHER
     -----------------------
     Kevin S. Helmbacher
     Secretary










                                      15.