AS RIGHTS AGENT RIGHTS AGREEMENT

CORVAS INTERNATIONAL, INC.

AND

AMERICAN STOCK TRANSFER AND TRUST COMPANY

AS RIGHTS AGENT

RIGHTS AGREEMENT

DATED AS OF SEPTEMBER 18, 1997

TABLE OF CONTENTS

PAGE

SECTION 1. CERTAIN DEFINITIONS. . . . . . . . . . . . . . . . . . . . . . 1

SECTION 2. APPOINTMENT OF RIGHTS AGENT. . . . . . . . . . . . . . . . . . 4

SECTION 3. ISSUE OF RIGHT CERTIFICATES. . . . . . . . . . . . . . . . . . 5

SECTION 4. FORM OF RIGHT CERTIFICATES . . . . . . . . . . . . . . . . . . 7

SECTION 5. COUNTERSIGNATURE AND REGISTRATION. . . . . . . . . . . . . . . 7

SECTION 6. TRANSFER, SPLIT UP, COMBINATION AND EXCHANGE OF
RIGHT CERTIFICATES; MUTILATED, DESTROYED, LOST OR
STOLEN RIGHT CERTIFICATES. . . . . . . . . . . . . . . . . . . 8

SECTION 7. EXERCISE OF RIGHTS; PURCHASE PRICE; EXPIRATION
DATE OF RIGHTS . . . . . . . . . . . . . . . . . . . . . . . . 9

SECTION 8. CANCELLATION AND DESTRUCTION OF RIGHT CERTIFICATES . . . . . . 11

SECTION 9. AVAILABILITY OF PREFERRED SHARES . . . . . . . . . . . . . . . 11

SECTION 10. PREFERRED SHARES RECORD DATE . . . . . . . . . . . . . . . . . 12

SECTION 11. ADJUSTMENT OF PURCHASE PRICE, NUMBER OF SHARES
OR NUMBER OF RIGHTS. . . . . . . . . . . . . . . . . . . . . . 12

SECTION 12. CERTIFICATE OF ADJUSTED PURCHASE PRICE OR NUMBER OF SHARES . . 20

SECTION 13. CONSOLIDATION, MERGER OR SALE OR TRANSFER OF ASSETS
OR EARNING POWER . . . . . . . . . . . . . . . . . . . . . . . 21

SECTION 14. FRACTIONAL RIGHTS AND FRACTIONAL SHARES. . . . . . . . . . . . 24

SECTION 15. RIGHTS OF ACTION . . . . . . . . . . . . . . . . . . . . . . . 25

SECTION 16. AGREEMENT OF RIGHT HOLDERS . . . . . . . . . . . . . . . . . . 26

SECTION 17. RIGHT CERTIFICATE HOLDER NOT DEEMED A STOCKHOLDER. . . . . . . 26

SECTION 18. CONCERNING THE RIGHTS AGENT. . . . . . . . . . . . . . . . . . 27

TABLE OF CONTENTS
(CONTINUED)

PAGE

SECTION 19. MERGER OR CONSOLIDATION OR CHANGE OF NAME OF RIGHTS AGENT. . . 27

SECTION 20. DUTIES OF RIGHTS AGENT . . . . . . . . . . . . . . . . . . . . 28

SECTION 21. CHANGE OF RIGHTS AGENT . . . . . . . . . . . . . . . . . . . . 30

SECTION 22. ISSUANCE OF NEW RIGHT CERTIFICATES . . . . . . . . . . . . . . 31

SECTION 23. REDEMPTION . . . . . . . . . . . . . . . . . . . . . . . . . . 31

SECTION 24. EXCHANGE . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

SECTION 25. NOTICE OF CERTAIN EVENTS . . . . . . . . . . . . . . . . . . . 35

SECTION 26. NOTICES. . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

SECTION 27. SUPPLEMENTS AND AMENDMENTS . . . . . . . . . . . . . . . . . . 36

SECTION 28. DETERMINATION AND ACTIONS BY THE BOARD OF DIRECTORS, ETC . . . 37

SECTION 29. SUCCESSORS . . . . . . . . . . . . . . . . . . . . . . . . . . 37

SECTION 30. BENEFITS OF THIS AGREEMENT . . . . . . . . . . . . . . . . . . 38

SECTION 31. SEVERABILITY . . . . . . . . . . . . . . . . . . . . . . . . . 38

SECTION 32. GOVERNING LAW. . . . . . . . . . . . . . . . . . . . . . . . . 38

SECTION 33. COUNTERPARTS . . . . . . . . . . . . . . . . . . . . . . . . . 38

SECTION 34. DESCRIPTIVE HEADINGS . . . . . . . . . . . . . . . . . . . . . 38

Exhibit A - Certificate of Designation

Exhibit B - Form of Right Certificate

Exhibit C - Summary of Rights to Purchase Preferred Shares

ii.

RIGHTS AGREEMENT

THIS RIGHTS AGREEMENT ("AGREEMENT"), dated as of September 18, 1997,
between CORVAS INTERNATIONAL, INC., a Delaware corporation (the "Company"), and
AMERICAN STOCK TRANSFER AND TRUST COMPANY ("Rights Agent").

The Board of Directors of the Company has authorized and declared a
dividend of one preferred share purchase right (a "Right") for each Common Share
(as such term is hereinafter defined) outstanding at the close of business on
September 18, 1997 (the "Record Date"), each Right representing the right to
purchase one one-hundredth of a Preferred Share (as such term is hereinafter
defined), upon the terms and subject to the conditions herein set forth, and has
further authorized and directed the issuance of one Right with respect to each
Common Share that shall become outstanding between the Record Date and the
earliest to occur of the Distribution Date, the Redemption Date and the Final
Expiration Date (as such terms are hereinafter defined); PROVIDED, HOWEVER, that
Rights may be issued with respect to Common Shares that shall become outstanding
after the Distribution Date and prior to the earlier of the Redemption Date and
the Final Expiration Date in accordance with the provisions of Section 22
hereof.

Accordingly, in consideration of the premises and the mutual agreements
herein set forth, the parties hereby agree as follows:

SECTION 1. CERTAIN DEFINITIONS. For purposes of this Agreement, the
following terms have the meanings indicated:

(a) "ACQUIRING PERSON" shall mean any Person (as such term is hereinafter
defined) who or which, together with all Affiliates and Associates (as such
terms are hereinafter defined) of such Person, shall be the Beneficial Owner (as
such term is hereinafter defined) of 20% or more of the Common Shares then
outstanding. Notwithstanding the foregoing, (A) the term Acquiring Person shall
not include (i) the Company, (ii) any Subsidiary (as such term is hereinafter
defined) of the Company, (iii) any employee benefit or compensation plan of the
Company or any Subsidiary of the Company, or (iv) any entity holding Common
Shares for or pursuant to the terms of any such employee benefit or compensation
plan, and (B) no Person shall become an "Acquiring Person" either (x) as the
result of an acquisition of Common Shares by the Company which, by reducing the
number of shares outstanding, increases the proportionate number of shares
beneficially owned by such Person to 20% or more of the Common Shares then
outstanding; PROVIDED, HOWEVER, that if a Person shall become the Beneficial
Owner of 20% or more of the Common Shares then outstanding by reason of share
purchases by the Company and shall, following written notice from, or public

disclosure by the Company of such share purchases by the Company, become the
Beneficial Owner of any additional Common Shares without the prior written
consent of the Company and shall then Beneficially Own more than 20% of the
Common Shares then outstanding, then such Person shall be deemed to be an
"Acquiring Person," (y) as the result of the acquisition of Common Shares
directly from the Company, PROVIDED HOWEVER that if a Person shall become the
Beneficial Owner of 20% or more of the Common Shares then outstanding by reason
of share purchases directly from the Company and shall, after that date, become
Beneficial Owner of any additional Common Shares without the prior written
consent of the Company and shall then Beneficially Own more than 20% of the
Common Shares then outstanding, then such Person shall be deemed to be an
"Acquiring Person," or (z) if the Board of Directors determines in good faith
that a Person who would otherwise be an "Acquiring Person," as defined pursuant
to the foregoing provisions of this paragraph (a), has become such
inadvertently, and such Person divests, as promptly as practicable (as
determined in good faith by the Board of Directors), but in any event within
five Business Days, following receipt of written notice from the Company of such
event, of a sufficient number of Common Shares so that such Person would no
longer be an Acquiring Person, as defined pursuant to the foregoing provisions
of this paragraph (a), then such Person shall not be deemed to be an "Acquiring
Person" for any purposes of this Agreement.

(b) "AFFILIATE" and "ASSOCIATE" shall have the respective meanings
ascribed to such terms in Rule 12b-2 of the General Rules and Regulations under
the Securities Exchange Act of 1934, as amended (the "Exchange Act"), as in
effect on the date of this Agreement; PROVIDED, HOWEVER, that the limited
partners of a limited partnership shall not be deemed to be Associates of such
limited partnership solely by virtue of their limited partnership interest.

(i) which such Person or any of such Person's Affiliates or
Associates is deemed to beneficially own, within the meaning of Rule 13d-3 of
the General Rules and Regulations under the Exchange Act as in effect on the
date of this Rights Agreement;

(ii) which such Person or any of such Person's 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 (other than customary agreements with and between
underwriters and selling group members with respect to a bona fide public
offering of securities, or upon the exercise of conversion rights, exchange
rights, rights (other than these Rights), warrants or options, or otherwise;
PROVIDED, HOWEVER, that a Person shall not be deemed the Beneficial Owner of, or
to beneficially own, securities tendered pursuant to a tender or exchange offer
made by or

on behalf of such Person or any of such Person's Affiliates or Associates until
such tendered securities are accepted for purchase or exchange; or (B) the right
to vote pursuant to any agreement, arrangement or understanding; PROVIDED,
HOWEVER, that a Person shall not be deemed the Beneficial Owner of, or to
beneficially own, any security if the agreement, arrangement or understanding to
vote such security (1) arises solely from a revocable proxy or consent given to
such Person in response to a public proxy or consent solicitation made pursuant
to, and in accordance with, the applicable rules and regulations promulgated
under the Exchange Act and (2) is not also then reportable on Schedule 13D under
the Exchange Act (or any comparable or successor report); or

(iii) which are beneficially owned, directly or indirectly, by any
other Person with which such Person or any of such Person's Affiliates or
Associates has any agreement, arrangement or understanding (other than customary
agreements with and between underwriters and selling group members with respect
to a bona fide public offering of securities) for the purpose of acquiring,
holding, voting (except to the extent contemplated by the proviso to
Section 1(c)(ii)(B) hereof) or disposing of any securities of the Company.

Notwithstanding anything in this definition of Beneficial Ownership to the
contrary, the phrase, "then outstanding," when used with reference to a Person's
Beneficial Ownership of securities of the Company, shall mean the number of such
securities then issued and outstanding together with the number of such
securities not then actually issued and outstanding which such Person would be
deemed to own beneficially hereunder.

(d) "BUSINESS DAY" shall mean any day other than a Saturday, a Sunday, or
a day on which banking institutions in the State of New York are authorized or
obligated by law or executive order to close.

(e) "CLOSE OF BUSINESS" on any given date shall mean 5:00 p.m., Eastern
Time, on such date; PROVIDED, HOWEVER, that if such date is not a Business Day
it shall mean 5:00 p.m., Eastern Time, on the next succeeding Business Day.

(f) "COMMON SHARES" shall mean the shares of common stock, par value $.001
per share, of the Company; PROVIDED, HOWEVER, that, "Common Shares," when used
in this Agreement in connection with a specific reference to any Person other
than the Company, shall mean the capital stock (or equity interest) with the
greatest voting power of such other Person or, if such other Person is a
Subsidiary of another Person, the Person or Persons which ultimately control
such first-mentioned Person.

(g) "DISTRIBUTION DATE" shall have the meaning set forth in Section 3
hereof.

(h) "FINAL EXPIRATION DATE" shall have the meaning set forth in Section 7
hereof.

(i) "INTERESTED STOCKHOLDER" shall mean any Acquiring Person or any
Affiliate or Associate of an Acquiring Person or any other Person in which any
such Acquiring Person, Affiliate or Associate has an interest, or any other
Person acting directly or indirectly on behalf of or in concert with any such
Acquiring Person, Affiliate or Associate.

(j) "PERSON" shall mean any individual, firm, corporation or other entity,
and shall include any successor (by merger or otherwise) of such entity.

(k) "PREFERRED SHARES" shall mean shares of Series C Junior Participating
Preferred Stock, par value $.001 per share, of the Company having the
designations and the powers, preferences and rights, and the qualifications,
limitations and restrictions set forth in the Form of Certificate of Designation
attached to this Agreement as Exhibit A.

(l) "PURCHASE PRICE" shall have the meaning set forth in Section 7(b)
hereof.

(m) "REDEMPTION DATE" shall have the meaning set forth in Section 7
hereof.

(n) "SHARES ACQUISITION DATE" shall mean the first date of public
announcement by the Company or an Acquiring Person that an Acquiring Person has
become such PROVIDED, HOWEVER, that, if such Person is determined not to have
become an Acquiring Person pursuant to clause (z) of Subsection 1(a)(B) hereof,
then no Shares Acquisition Date shall be deemed to have occurred.

(o) "SUBSIDIARY" of any Person shall mean any corporation or other entity
of which a majority of the voting power of the voting equity securities or
equity interest is owned, directly or indirectly, by such Person.

(p) "TRANSACTION" shall mean any merger, consolidation or sale of assets
described in Section 13(a) hereof or any acquisition of Common Shares which
would result in a Person becoming an Acquiring Person or a Principal Party (as
such term is hereinafter defined).

(q) "TRANSACTION PERSON" with respect to a Transaction shall mean (i) any
Person who (x) is or will become an Acquiring Person or a Principal Party (as
such term is hereinafter defined) if the Transaction were to be consummated and
(y) directly or indirectly proposed or nominated a director of the Company which
director is in office at the time of consideration of the Transaction, or
(ii) an Affiliate or Associate of such a Person.

SECTION 2. APPOINTMENT OF RIGHTS AGENT. The Company hereby appoints the
Rights Agent to act as agent for the Company and the holders of the Rights (who,
in accordance with Section 3 hereof, shall prior to the Distribution Date also
be the holders

of the Common Shares) in accordance with the terms and conditions hereof, and
the Rights Agent hereby accepts such appointment. The Company may from time to
time appoint such co-Rights Agents as it may deem necessary or desirable.

SECTION 3. ISSUE OF RIGHT CERTIFICATES.

(a) Until the earlier of (i) the Shares Acquisition Date or (ii) the tenth
Business Day (or such later date as may be determined by action of the Board of
Directors prior to such time as any Person becomes an Acquiring Person) after
the date of the commencement (determined in accordance with Rule 14d-2 under the
Exchange Act) by any Person (other than the Company, any Subsidiary of the
Company, any employee benefit plan of the Company or of any Subsidiary of the
Company or any entity holding Common Shares for or pursuant to the terms of any
such plan) of, or of the first public announcement of the intention of any
Person (other than the Company, any Subsidiary of the Company, any employee
benefit plan of the Company or of any Subsidiary of the Company or any entity
holding Common Shares for or pursuant to the terms of any such plan) to
commence, a tender or exchange offer (which intention to commence remains in
effect for five Business Days after such announcement), the consummation of
which would result in any Person becoming an Acquiring Person (including any
such date which is after the date of this Agreement and prior to the issuance of
the Rights, the earlier of such dates being herein referred to as the
"Distribution Date"), (x) the Rights will be evidenced by the certificates for
Common Shares registered in the names of the holders thereof (which certificates
shall also be deemed to be Right Certificates) and not by separate Right
Certificates, and (y) the Rights (and the right to receive Right Certificates
therefor) will be transferable only in connection with the transfer of Common
Shares. As soon as practicable after the Distribution Date, the Company will
prepare and execute, the Rights Agent will countersign, and the Company will
send or cause to be sent (and the Rights Agent will, if requested, send) by
first-class, insured, postage-prepaid mail, to each record holder of Common
Shares as of the Close of Business on the Distribution Date, at the address of
such holder shown on the records of the Company, a Right Certificate, in
substantially the form of Exhibit B hereto (a "Right Certificate"), evidencing
one Right for each Common Share so held, subject to the adjustment provisions of
Section 11 of this Rights Agreement. As of the Distribution Date, the Rights
will be evidenced solely by such Right Certificates.

(b) On the Record Date, or as soon as practicable thereafter, the Company
will send (directly or through the Rights Agent or its transfer agent) a copy of
a Summary of Rights to Purchase Preferred Shares, in substantially the form of
Exhibit C hereto (the "Summary of Rights"), by first-class, postage-prepaid
mail, to each record holder of Common Shares as of the Close of Business on the
Record Date, at the address of such holder shown on the records of the Company.
With respect to certificates for Common Shares outstanding as of the Record
Date, until the Distribution Date, the Rights will be

evidenced by such certificates registered in the names of the holders thereof.
Until the Distribution Date (or the earlier of the Redemption Date and the Final
Expiration Date), the surrender for transfer of any certificate for Common
Shares outstanding on the Record Date shall also constitute the transfer of the
Rights associated with the Common Shares represented thereby.

(c) Certificates for Common Shares which become outstanding (including,
without limitation, reacquired Common Shares referred to in the last sentence of
this paragraph (c)) after the Record Date but prior to the earliest of the
Distribution Date, the Redemption Date or the Final Expiration Date shall have
impressed on, printed on, written on or otherwise affixed to them the following
legend:

This certificate also evidences and entitles the holder hereof to
certain rights as set forth in a Rights Agreement between CORVAS
INTERNATIONAL, INC. (the "Company") and AMERICAN STOCK TRANSFER AND
TRUST COMPANY as Rights Agent (the "Rights Agent"), dated as of
September 18, 1997, as amended from time to time (the "Rights
Agreement"), the terms of which are hereby incorporated herein by
reference and a copy of which is on file at the principal executive
offices of the Company. Under certain circumstances, as set forth in
the Rights Agreement, such Rights will be evidenced by separate
certificates and will no longer be evidenced by this certificate. The
Company will mail to the holder of this certificate a copy of the
Rights Agreement without charge after receipt of a written request
therefor. As described in the Rights Agreement, Rights issued to any
Person who becomes an Acquiring Person or an Affiliate or Associate
thereof (as defined in the Rights Agreement) and certain related
persons, whether currently held by or on behalf of such Person or by
any subsequent holder, shall become null and void.

With respect to such certificates containing the foregoing legend, until the
Distribution Date, the Rights associated with the Common Shares represented by
such certificates shall be evidenced by such certificates alone, and the
surrender for transfer of any such certificate shall also constitute the
transfer of the Rights associated with the Common Shares represented thereby.
In the event that the Company purchases or acquires any Common Shares after the
Record Date but prior to the Distribution Date, any Rights associated with such
Common Shares shall be deemed canceled and retired so that the Company shall not
be entitled to exercise any Rights associated with the Common Shares which are
no longer outstanding. Notwithstanding this Section 3(c), the omission of a

legend shall not affect the enforceability of any part of this Rights Agreement
or the rights of any holder of the Rights.

SECTION 4. FORM OF RIGHT CERTIFICATES.

(a) The Right Certificates (and the form of election to purchase Preferred
Shares, the form of assignment and the form of certification to be printed on
the reverse thereof) shall be substantially the same as Exhibit B hereto and may
have such marks of identification or designation and such legends, summaries or
endorsements printed thereon as the Company may deem appropriate and as are not
inconsistent with the provisions of this Agreement, or as may be required to
comply with any applicable law or with any rule or regulation made pursuant
thereto or with any rule or regulation of any stock exchange on which the Rights
may from time to time be listed, or to conform to usage. Subject to the
provisions of Sections 7,11 and 22 hereof, the Right Certificates shall entitle
the holders thereof to purchase such number of one one-hundredths of a Preferred
Share as shall be set forth therein at the price per one one-hundredth of a
Preferred Share set forth therein (the "Purchase Price"), but the number of such
one one-hundredths of a Preferred Share and the Purchase Price shall be subject
to adjustment as provided herein.

(b) Any Right Certificate issued pursuant to Section 3(a) or Section 22
hereof that represents Rights which are null and void pursuant to Section
11(a)(ii) hereof and any Right Certificate issued pursuant to Section 6 or
Section 11 hereof upon transfer, exchange, replacement or adjustment of any
other Right Certificate referred to in this sentence, shall contain (to the
extent feasible) the following legend:

The Rights represented by this Right Certificate are or were
beneficially owned by a Person who was or became an Acquiring Person
or an Affiliate or Associate of an Acquiring Person (as such terms are
defined in the Rights Agreement). Accordingly, this Right Certificate
and the Rights represented hereby are null and void.

The provisions of Section 11(a)(ii) hereof shall be operative whether or not the
foregoing legend is contained on any such Right Certificate.

SECTION 5. COUNTERSIGNATURE AND REGISTRATION. The Right Certificates shall
be executed on behalf of the Company by its Chairman of the Board, its Chief
Executive Officer, its President, its Vice Chairman of the Board, its Chief
Financial Officer, or any of its Vice Presidents, either manually or by
facsimile signature, shall have affixed thereto the Company's seal or a
facsimile thereof, and shall be attested by the Secretary or an Assistant
Secretary of the Company, either manually or by facsimile signature. The Right

Certificates shall be manually countersigned by the Rights Agent and shall not
be valid for any purpose unless countersigned. In case any officer of the
Company who shall have signed any of the Right Certificates shall cease to be
such officer of the Company before countersignature by the Rights Agent and
issuance and delivery by the Company, such Right Certificates, nevertheless, may
be countersigned by the Rights Agent and issued and delivered by the Company
with the same force and effect as though the person who signed such Right
Certificates had not ceased to be such officer of the Company; and any Right
Certificate may be signed on behalf of the Company by any person who, at the
actual date of the execution of such Right Certificate, shall be a proper
officer of the Company to sign such Right Certificate, although at the date of
the execution of this Agreement any such person was not such an officer.

Following the Distribution Date, the Rights Agent will keep or cause to be
kept, at its office designated for such purpose, books for registration and
transfer of the Right Certificates issued hereunder. Such books shall show the
names and addresses of the respective holders of the Right Certificates, the
number of Rights evidenced on its face by each of the Right Certificates and the
date of each of the Right Certificates.

SECTION 6. TRANSFER, SPLIT UP, COMBINATION AND EXCHANGE OF RIGHT
CERTIFICATES; MUTILATED, DESTROYED, LOST OR STOLEN RIGHT CERTIFICATES. Subject
to the provisions of Section 11(a)(ii), Section 14 and Section 24 hereof, at any
time after the Close of Business on the Distribution Date, and at or prior to
the Close of Business on the earlier of the Redemption Date or the Final
Expiration Date, any Right Certificate or right certificates may be transferred,
split up, combined or exchanged for another Right Certificate or right
certificates, entitling the registered holder to purchase a like number of one
one-hundredths of a Preferred Share as the Right Certificate or Right
Certificates surrendered then entitled such holder to purchase. Any registered
holder desiring to transfer, split up, combine or exchange any Right Certificate
or Right Certificates shall make such request in writing delivered to the Rights
Agent, and shall surrender the Right Certificate or Right Certificates to be
transferred, split up, combined or exchanged at the office of the Rights Agent
designated for such purpose. Neither the Rights Agent nor the Company shall be
obligated to take any action whatsoever with respect to the transfer of any such
surrendered Right Certificate until the registered holder shall have completed
and signed the certificate contained in the form of assignment on the reverse
side of such Right Certificate and shall have provided such additional evidence
of the identity of the Beneficial Owner (or former Beneficial Owner) or
Affiliates or Associates thereof as the Company shall reasonably request.
Thereupon the Rights Agent shall, subject to Section 11(a)(ii), Section 14 and
Section 24 hereof, countersign and deliver to the person entitled thereto a
Right Certificate or Right Certificates, as the case may be, as so requested.
The Company may require payment of a sum sufficient to cover any tax or
governmental charge that may be imposed in connection with any transfer, split
up, combination or exchange of Right Certificates.

Upon receipt by the Company and the Rights Agent of evidence reasonably
satisfactory to them of the loss, theft, destruction or mutilation of a Right
Certificate, and, in case of loss, theft or destruction, of indemnity or
security reasonably satisfactory to them, and, at the Company's request,
reimbursement to the Company and the Rights Agent of all reasonable expenses
incidental thereto, and upon surrender to the Rights Agent and cancellation of
the Right Certificate if mutilated, the Company will issue, execute and deliver
a new Right Certificate of like tenor to the Rights Agent for countersignature
and delivery to the registered holder in lieu of the Right Certificate so lost,
stolen, destroyed or mutilated.

Notwithstanding any other provisions hereof, the Company and the Rights
Agent may amend this Rights Agreement to provide for uncertificated Rights in
addition to or in place of Rights evidenced by Rights Certificates.

SECTION 7. EXERCISE OF RIGHTS; PURCHASE PRICE; EXPIRATION DATE OF RIGHTS.

(a) The registered holder of any Right Certificate may exercise the Rights
evidenced thereby (except as otherwise provided herein) in whole or in part at
any time after the Distribution Date upon surrender of the Right Certificate,
with the form of election to purchase on the reverse side thereof duly executed,
to the Rights Agent at the office of the Rights Agent designated for such
purpose, together with payment of the Purchase Price for each one one-hundredth
of a Preferred Share (or such other number of shares or other securities) as to
which the Rights are exercised, at or prior to the earliest of (i) the Close of
Business on September 18, 2007 (the "Final Expiration Date"), (ii) the time at
which the Rights are redeemed as provided in Section 23 hereof (the "Redemption
Date"), or (iii) the time at which such Rights are exchanged as provided in
Section 24 hereof.

(b) The purchase price (the "Purchase Price") for each one one-hundredth
of a Preferred Share pursuant to the exercise of a Right shall initially be $50,
shall be subject to adjustment from time to time as provided in Sections 11 and
13 hereof and shall be payable in lawful money of the United States of America
in accordance with paragraph (c) below.

(c) Upon receipt of a Right Certificate representing exercisable Rights,
with the form of election to purchase duly executed, accompanied by payment of
the Purchase Price for the shares to be purchased and an amount equal to any
applicable transfer tax required to be paid by the holder of such Right
Certificate in accordance with Section 9 hereof by certified check, cashier's
check, bank draft or money order payable to the order of the Company, the Rights
Agent shall thereupon promptly (i) (A) requisition from any transfer agent for
the Preferred Shares certificates for the number of Preferred Shares to be
purchased and the Company hereby irrevocably authorizes its transfer agent to
comply

with all such requests, or (B) if the Company, in its sole discretion, shall
have elected to deposit the Preferred Shares issuable upon exercise of the
Rights hereunder into a depository, requisition from the depositary agent
depositary receipts representing such number of one one-hundredths of a
Preferred Share as are to be purchased (in which case certificates for the
Preferred Shares represented by such receipts shall be deposited by the transfer
agent with the depositary agent) and the Company hereby directs the depositary
agent to comply with such request, (ii) when appropriate, requisition from the
Company the amount of cash to be paid in lieu of issuance of fractional shares
in accordance with Section 14 hereof, (iii) after receipt of such certificates
or depositary receipts, cause the same to be delivered to or upon the order of
the registered holder of such Right Certificate, registered in such name or
names as may be designated by such holder and (iv) when appropriate, after
receipt, deliver such cash to or upon the order of the registered holder of such
Right Certificate. In the event that the Company is obligated to issue
securities of the Company other than Preferred Shares (including Common Shares)
of the Company pursuant to Section 11(a) hereof, the Company will make all
arrangements necessary so that such other securities are available for
distribution by the Rights Agent, if and when appropriate.

In addition, in the case of an exercise of the Rights by a holder pursuant
to Section 11(a)(ii) hereof, the Rights Agent shall return such Right
Certificate to the registered holder thereof after imprinting, stamping or
otherwise indicating thereon that the rights represented by such Right
Certificate no longer include the rights provided by Section 11(a)(ii) hereof,
and, if fewer than all the Rights represented by such Right Certificate were so
exercised, the Rights Agent shall indicate on the Right Certificate the number
of Rights represented thereby which continue to include the rights provided by
Section 11(a)(ii) hereof.

(d) In case the registered holder of any Right Certificate shall exercise
fewer than all the Rights evidenced thereby, a new Right Certificate evidencing
Rights equivalent to the Rights remaining unexercised shall be issued by the
Rights Agent to the registered holder of such Right Certificate or to his duly
authorized assigns, subject to the provisions of Section 14 hereof.

(e) The Company covenants and agrees that it will cause to be reserved and
kept available out of its authorized and unissued Preferred Shares or any
Preferred Shares held in its treasury, the number of Preferred Shares that will
be sufficient to permit the exercise in full of all outstanding Rights in
accordance with this Section 7.

(f) Notwithstanding anything in this Agreement to the contrary, neither
the Rights Agent nor the Company shall be obligated to undertake any action with
respect to a registered holder upon the occurrence of any purported exercise as
set forth in this Section 7 unless such registered holder shall have
(i) completed and signed the

10.

certification following the form of election to purchase set forth on the
reverse side of the Rights Certificate surrendered for such exercise and
(ii) provided such additional evidence of the identity of the Beneficial Owner
(or former Beneficial Owner) or Affiliates or Associates thereof as the Company
shall reasonably request.

SECTION 8. CANCELLATION AND DESTRUCTION OF RIGHT CERTIFICATES. All Right
Certificates surrendered for the purpose of exercise, transfer, split up,
combination or exchange shall, if surrendered to the Company or to any of its
agents, be delivered to the Rights Agent for cancellation or in canceled form,
or, if delivered or surrendered to the Rights Agent, shall be canceled by it,
and no Right Certificates shall be issued in lieu thereof except as expressly
permitted by any of the provisions of this Agreement. The Company shall deliver
to the Rights Agent for cancellation and retirement, and the Rights Agent shall
so cancel and retire, any other Right Certificate purchased or acquired by the
Company otherwise than upon the exercise thereof. The Rights Agent shall
deliver all canceled Right Certificates to the Company, or shall, at the written
request of the Company, destroy such canceled Right Certificates, and in such
case shall deliver a certificate of destruction thereof to the Company.

SECTION 9. AVAILABILITY OF PREFERRED SHARES. The Company covenants and
agrees that so long as the Preferred Shares (and, after the time a person
becomes an Acquiring Person, Common Shares or any other securities) issuable
upon the exercise of the Rights may be listed on any national securities
exchange or quotation system, the Company shall use its best efforts to cause,
from and after such time as the Rights become exercisable, all shares reserved
for such issuance to be listed on such exchange or quotation system upon
official notice of issuance upon such exercise.

The Company covenants and agrees that it will take all such action as may
be necessary to ensure that all Preferred Shares (or Common Shares and other
securities, as the case may be) delivered upon exercise of Rights shall, at the
time of delivery of the certificates for such Preferred Shares (subject to
payment of the Purchase Price), be duly and validly authorized and issued and
fully paid and nonassessable shares or other securities.

The Company further covenants and agrees that it will pay when due and
payable any and all federal and state transfer taxes and charges which may be
payable in respect of the issuance or delivery of the Right Certificates or of
any Preferred Shares upon the exercise of Rights. The Company shall not,
however, be required to pay any transfer tax which may be payable in respect of
any transfer or delivery of Right Certificates to a person other than, or the
issuance or delivery of certificates or depositary receipts for the Preferred
Shares in a name other than that of, the registered holder of the Right
Certificate evidencing Rights surrendered for exercise or to issue or to deliver
any certificates or depositary receipts for Preferred Shares upon the exercise
of any Rights until any such tax

11.

shall have been paid (any such tax being payable by the holder of such Right
Certificate at the time of surrender) or until it has been established to the
Company's reasonable satisfaction that no such tax is due.

As soon as practicable after the Shares Acquisition Date, the Company shall
use its best efforts to:

(i) prepare and file a registration statement under the Securities
Act of 1933, as amended (the "Act"), with respect to the Rights and the
securities purchasable upon exercise of the Rights on an appropriate form, will
use its best efforts to cause such registration statement to become effective as
soon as practicable after such filing and will use its best efforts to cause
such registration statement to remain effective (with a prospectus at all times
meeting the requirements of the Act) until the Final Expiration Date; and

(ii) use its best efforts to qualify or register the Rights and the
securities purchasable upon exercise of the Rights under the blue sky laws of
such jurisdictions as may be necessary or appropriate.

SECTION 10. PREFERRED SHARES RECORD DATE. Each person in whose name any
certificate for Preferred Shares or other securities is issued upon the exercise
of Rights shall for all purposes be deemed to have become the holder of record
of the Preferred Shares or other securities represented thereby on, and such
certificate shall be dated, the date upon which the Right Certificate evidencing
such Rights was duly surrendered with the forms of election and certification
duly executed and payment of the Purchase Price (and any applicable transfer
taxes) was made; PROVIDED, HOWEVER, that if the date of such surrender and
payment is a date upon which the Preferred Shares or other securities transfer
books of the Company are closed, such person shall be deemed to have become the
record holder of such shares on, and such certificate shall be dated, the next
succeeding Business Day on which the Preferred Shares or other securities
transfer books of the Company are open. Prior to the exercise of the Rights
evidenced thereby, the holder of a Right Certificate, as such, shall not be
entitled to any rights of a holder of Preferred Shares for which the Rights
shall be exercisable, including, without limitation, the right to vote, to
receive dividends or other distributions or to exercise any preemptive rights,
and shall not be entitled to receive any notice of any proceedings of the
Company, except as provided herein.

SECTION 11. ADJUSTMENT OF PURCHASE PRICE, NUMBER OF SHARES OR NUMBER OF
RIGHTS. The Purchase Price, the number of Preferred Shares covered by each
Right and the number of Rights outstanding are subject to adjustment from time
to time as provided in this Section 11.

12.

(a) (i) In the event the Company shall at any time after the date of
this Agreement (A) declare a dividend on the Preferred Shares payable in
Preferred Shares, (B) subdivide the outstanding Preferred Shares, (C) combine
the outstanding Preferred Shares into a smaller number of Preferred Shares or
(D) issue any shares of its capital stock in a reclassification of the Preferred
Shares (including any such reclassification in connection with a consolidation
or merger in which the Company is the continuing or surviving corporation),
except as otherwise provided in this Section 11(a), the Purchase Price in effect
at the time of the record date for such dividend or of the effective date of
such subdivision, combination or reclassification, and the number and kind of
shares of capital stock issuable on such date, shall be proportionately adjusted
so that the holder of any Right exercised after such time shall be entitled to
receive the aggregate number and kind of shares of capital stock which, if such
Right had been exercised immediately prior to such date and at a time when the
Preferred Shares transfer books of the Company were open, such holder would have
owned upon such exercise and been entitled to receive by virtue of such
dividend, subdivision, combination or reclassification; PROVIDED, HOWEVER, that
in no event shall the consideration to be paid upon the exercise of one Right be
less than the aggregate par value of the shares of capital stock of the Company
issuable upon exercise of one Right. If an event occurs which would require an
adjustment under both Section 11(a)(i) and Section 11(a)(ii) hereof, the
adjustment provided for in this Section 11(a)(i) shall be in addition to, and
shall be made prior to any adjustment required pursuant to Section 11(a)(ii)
hereof.

(ii) Subject to Section 24 hereof and the provisions of the next
paragraph of this Section 11(a)(ii), in the event any Person shall become an
Acquiring Person, each holder of a Right shall, for a period of 60 days after
the later of such time any Person becomes an Acquiring Person or the effective
date of an appropriate registration statement under the Act pursuant to Section
9 hereof (PROVIDED, HOWEVER, that, if at any time prior to the expiration or
termination of the Rights there shall be a temporary restraining order, a
preliminary injunction, an injunction, or temporary suspension by the Board of
Directors, or similar obstacle to exercise of the Rights (the "Injunction")
which prevents exercise of the Rights, a new 60-day period shall commence on the
date the Injunction is removed), have a right to receive, upon exercise thereof
at a price equal to the then current Purchase Price multiplied by the number of
one one-hundredths of a Preferred Share for which a Right is then exercisable,
in accordance with the terms of this Agreement and in lieu of Preferred Shares,
such number of Common Shares as shall equal the result obtained by
(A) multiplying the then current Purchase Price by the number of one
one-hundredths of a Preferred Share for which a Right is then exercisable and
dividing that product by (B) 50% of the then current per share market price of
the Common Shares (determined pursuant to Section 11(d) hereof) on the date such
Person became an Acquiring Person; PROVIDED, HOWEVER, that if the transaction
that would otherwise give rise to the foregoing adjustment is also subject to
the provisions of

13.

Section 13 hereof, then only the provisions of Section 13 hereof shall apply and
no adjustment shall be made pursuant to this Section 11(a)(ii). In the event
that any Person shall become an Acquiring Person and the Rights shall then be
outstanding, the Company shall not take any action which would eliminate or
diminish the benefits intended to be afforded by the Rights.

Notwithstanding anything in this Agreement to the contrary, from and after
the time any Person becomes an Acquiring Person, any Rights beneficially owned
by (i) such Acquiring Person or an Associate or Affiliate of such Acquiring
Person, (ii) a transferee of such Acquiring Person (or of any such Associate or
Affiliate) who becomes a transferee after the Acquiring Person became such, or
(iii) a transferee of such Acquiring Person (or of any such Associate or
Affiliate) who becomes a transferee prior to or concurrently with the Acquiring
Person's becoming such and receives such Rights pursuant to either (A) a
transfer (whether or not for consideration) from the Acquiring Person to holders
of equity interests in such Acquiring Person or to any Person with whom the
Acquiring Person has any continuing agreement, arrangement or understanding
regarding the transferred Rights or (B) a transfer which the Board of Directors
of the Company has determined is part of a plan, arrangement or understanding
which has as a primary purpose or effect the avoidance of this
Section 11(a)(ii), shall become null and void without any further action and no
holder of such Rights shall have any rights whatsoever with respect to such
Rights, whether under any provision of this Agreement or otherwise. The Company
shall use all reasonable efforts to insure that the provisions of this
Section 11(a)(ii) and Section 4(b) hereof are complied with, but shall have no
liability to any holder of Right Certificates or other Person as a result of its
failure to make any determinations with respect to an Acquiring Person or its
Affiliates, Associates or transferees hereunder. No Right Certificate shall be
issued at any time upon the transfer of any Rights to an Acquiring Person whose
Rights would be void pursuant to the preceding sentence or any Associate or
Affiliate thereof or to any nominee of such Acquiring Person, Associate or
Affiliate; and any Right Certificate delivered to the Rights Agent for transfer
to an Acquiring Person whose Rights would be void pursuant to the preceding
sentence shall be canceled.

(iii) In lieu of issuing Common Shares in accordance with Section
11(a)(ii) hereof, the Company may, if a majority of the Board of Directors then
in office determines that such action is necessary or appropriate and not
contrary to the interests of holders of Rights, elect to (and, in the event that
the Board of Directors has not exercised the exchange right contained in Section
24(c) hereof and there are not sufficient treasury shares and authorized but
unissued Common Shares to permit the exercise in full of the Rights in
accordance with the foregoing subparagraph (ii), the Company shall) take all
such action as may be necessary to authorize, issue or pay, upon the exercise of
the Rights, cash (including by way of a reduction of the Purchase Price),
property, Common Shares, other securities or any combination thereof having an
aggregate value equal to the

14.

value of the Common Shares which otherwise would have been issuable pursuant to
Section 11(a)(ii) hereof, which aggregate value shall be determined by a
nationally recognized investment banking firm selected by a majority of the
Board of Directors then in office. For purposes of the preceding sentence, the
value of the Common Shares shall be determined pursuant to Section 11(d) hereof.
Any such election by the Board of Directors must be made within 60 days
following the date on which the event described in Section 11(a)(ii) hereof
shall have occurred. Following the occurrence of the event described in Section
11(a)(ii) hereof, a majority of the Board of Directors then in office may
suspend the exercisability of the Rights for a period of up to 60 days following
the date on which the event described in Section 11(a)(ii) hereof shall have
occurred to the extent that such directors have not determined whether to
exercise their rights of election under this Section 11(a)(iii). In the event
of any such suspension, the Company shall issue a public announcement stating
that the exercisability of the Rights has been temporarily suspended.

(b) In case the Company shall fix a record date for the issuance of
rights, options or warrants to all holders of Preferred Shares entitling them
(for a period expiring within 45 calendar days after such record date) to
subscribe for or purchase Preferred Shares (or shares having the same
designations and the powers, preferences and rights, and the qualifications,
limitations and restrictions as the Preferred Shares ("equivalent preferred
shares")) or securities convertible into Preferred Shares or equivalent
preferred shares at a price per Preferred Share or equivalent preferred share
(or having a conversion price per share, if a security convertible into
Preferred Shares or equivalent preferred shares) less than the then current per
share market price of the Preferred Shares (as such term is hereinafter defined)
on such record date, the Purchase Price to be in effect after such record date
shall be determined by multiplying the Purchase Price in effect immediately
prior to such record date by a fraction, the numerator of which shall be the
number of Preferred Shares outstanding on such record date plus the number of
Preferred Shares which the aggregate offering price of the total number of
Preferred Shares and/or equivalent preferred shares so to be offered (and/or the
aggregate initial conversion price of the convertible securities so to be
offered) would purchase at such current market price and the denominator of
which shall be the number of Preferred Shares outstanding on such record date
plus the number of additional Preferred Shares and/or equivalent preferred
shares to be offered for subscription or purchase (or into which the convertible
securities so to be offered are initially convertible); PROVIDED, HOWEVER, that
in no event shall the consideration to be paid upon the exercise of one Right be
less than the aggregate par value of the shares of capital stock of the Company
issuable upon exercise of one Right. In case such subscription price may be
paid in a consideration part or all of which shall be in a form other than cash,
the value of such consideration shall be as determined in good faith by the
Board of Directors of the Company, whose determination shall be described in a
statement filed with the Rights Agent. Preferred Shares owned by

15.

or held for the account of the Company shall not be deemed outstanding for the
purpose of any such computation. Such adjustment shall be made successively
whenever such a record date is fixed; and in the event that such rights, options
or warrants are not so issued, the Purchase Price shall be adjusted to be the
Purchase Price which would then be in effect if such record date had not been
fixed.

(c) In case the Company shall fix a record date for the making of a
distribution to all holders of the Preferred Shares (including any such
distribution made in connection with a consolidation or merger in which the
Company is the continuing or surviving corporation) of evidences of indebtedness
or assets (other than a regular quarterly cash dividend or a dividend payable in
Preferred Shares) or subscription rights or warrants (excluding those referred
to in Section 11(b) hereof), the Purchase Price to be in effect after such
record date shall be determined by multiplying the Purchase Price in effect
immediately prior to such record date by a fraction, the numerator of which
shall be the then current per share market price of the Preferred Shares (as
such term is hereinafter defined) on such record date, less the fair market
value (as determined in good faith by the Board of Directors of the Company,
whose determination shall be described in a statement filed with the Rights
Agent) of the portion of the assets or evidences of indebtedness so to be
distributed or of such subscription rights or warrants applicable to one
Preferred Share and the denominator of which shall be such current per share
market price of the Preferred Shares; PROVIDED, HOWEVER, that in no event shall
the consideration to be paid upon the exercise of one Right be less than the
aggregate par value of the shares of capital stock of the Company to be issued
upon exercise of one Right. Such adjustments shall be made successively
whenever such a record date is fixed; and in the event that such distribution is
not so made, the Purchase Price shall again be adjusted to be the Purchase Price
which would then be in effect if such record date had not been fixed.

(d) (i) For the purpose of any computation hereunder, the "current per
share market price" of any security (a "Security" for the purpose of this
Section 11(d)(i)) on any date shall be deemed to be the average of the daily
closing prices per share of such Security for the 30 consecutive Trading Days
(as such term is hereinafter defined) immediately prior to such date; PROVIDED,
HOWEVER, that in the event that the current per share market price of the
Security is determined during a period following the announcement by the issuer
of such Security of (A) a dividend or distribution on such Security payable in
shares of such Security or securities convertible into such shares, or (B) any
subdivision, combination or reclassification of such Security or securities
convertible into such shares, or (C) any subdivision, combination or
reclassification of such Security and prior to the expiration of 30 Trading Days
after the ex-dividend date for such dividend or distribution, or the record date
for such subdivision, combination or reclassification, then, and in each such
case, the current per share market price shall be appropriately adjusted to
reflect the current market price per share equivalent of such

16.

Security. The closing price for each day shall be the last sale price, regular
way, or, in case no such sale takes place on such day, the average of the
closing bid and asked prices, regular way, in either case as reported in the
principal consolidated transaction reporting system with respect to securities
listed or admitted to trading on the New York Stock Exchange or, if the Security
is not listed or admitted to trading on the New York Stock Exchange, as reported
in the principal consolidated transaction reporting system with respect to
securities listed on the principal national securities exchange on which the
Security is listed or admitted to trading or as reported on the Nasdaq National
Market or, if the Security is not listed or admitted to trading on any national
securities exchange or reported on the Nasdaq National Market, the last quoted
price or, if not so quoted, the average of the high bid and low asked prices in
the over-the-counter market, as reported by the National Association of
Securities Dealers, Inc. Automated Quotations System ("Nasdaq") or such other
system then in use, or, if on any such date the Security is not quoted by any
such organization, the average of the closing bid and asked prices as furnished
by a professional market maker making a market in the Security selected by the
Board of Directors of the Company or, if on any such date no professional market
maker is making a market in the Security, the price as determined in good faith
by the Board of Directors. The term "Trading Day" shall mean a day on which the
principal national securities exchange on which the Security is listed or
admitted to trading is open for the transaction of business or, if the Security
is not listed or admitted to trading on any national securities exchange, a
Business Day.

(ii) For the purpose of any computation hereunder, the "current per
share market price" of the Preferred Shares shall be determined in accordance
with the method set forth in Section 11(d)(i) hereof. If the Preferred Shares
are not publicly traded, the "current per share market price" of the Preferred
Shares shall be conclusively deemed to be the current per share market price of
the Common Shares as determined pursuant to Section 11(d)(i) hereof
(appropriately adjusted to reflect any stock split, stock dividend or similar
transaction occurring after the date hereof) multiplied by one hundred. If
neither the Common Shares nor the Preferred Shares are publicly held or so
listed or traded, "current per share market price" shall mean the fair value per
share as determined in good faith by the Board of Directors of the Company,
whose determination shall be described in a statement filed with the Rights
Agent.

(e) No adjustment in the Purchase Price shall be required unless such
adjustment would require an increase or decrease of at least 1% in the Purchase
Price; PROVIDED, HOWEVER, that any adjustments which by reason of this
Section 11(e) are not required to be made shall be carried forward and taken
into account in any subsequent adjustment. All calculations under this
Section 11 shall be made to the nearest cent or to the nearest one one-hundredth
of a Preferred Share or one ten-thousandth of any other share or security as the
case may be. Notwithstanding the first sentence of this Section 11(e), any
adjustment required by this Section 11 shall be made no later than the

17.

earlier of (i) three years from the date of the transaction which requires such
adjustment or (ii) the date of the expiration of the right to exercise any
Rights.

(f) If as a result of an adjustment made pursuant to Section 11(a) hereof,
the holder of any Right thereafter exercised shall become entitled to receive
any shares of capital stock of the Company other than Preferred Shares,
thereafter the number of such other shares so receivable upon exercise of any
Right shall be subject to adjustment from time to time in a manner and on terms
as nearly equivalent as practicable to the provisions with respect to the
Preferred Shares contained in Sections 11(a) through 11(c) hereof, inclusive,
and the provisions of Sections 7, 9, 10, 13 and 14 hereof with respect to the
Preferred Shares shall apply on like terms to any such other shares.

(g) All Rights originally issued by the Company subsequent to any
adjustment made to the Purchase Price hereunder shall evidence the right to
purchase, at the adjusted Purchase Price, the number of one one-hundredths of a
Preferred Share purchasable from time to time hereunder upon exercise of the
Rights, all subject to further adjustment as provided herein.

(h) Unless the Company shall have exercised its election as provided in
Section 11(i) hereof, upon each adjustment of the Purchase Price as a result of
the calculations made in Section 11(b) and Section 11(c) hereof, each Right
outstanding immediately prior to the making of such adjustment shall thereafter
evidence the right to purchase, at the adjusted Purchase Price, that number of
one one-hundredths of a Preferred Share (calculated to the nearest one
one-millionth of a Preferred Share) obtained by (i) multiplying (x) the number
of one one-hundredths of a Preferred Share covered by a Right immediately prior
to this adjustment by (y) the Purchase Price in effect immediately prior to such
adjustment of the Purchase Price and (ii) dividing the product so obtained by
the Purchase Price in effect immediately after such adjustment of the Purchase
Price.

(i) The Company may elect on or after the date of any adjustment of the
Purchase Price to adjust the number of Rights, in substitution for any
adjustment in the number of one one-hundredths of a Preferred Share purchasable
upon the exercise of a Right. Each of the Rights outstanding after such
adjustment of the number of Rights shall be exercisable for the number of one
one-hundredths of a Preferred Share for which a Right was exercisable
immediately prior to such adjustment. Each Right held of record prior to such
adjustment of the number of Rights shall become that number of Rights
(calculated to the nearest one ten-thousandth) obtained by dividing the Purchase
Price in effect immediately prior to adjustment of the Purchase Price by the
Purchase Price in effect immediately after adjustment of the Purchase Price.
The Company shall make a public announcement of its election to adjust the
number of Rights, indicating the record date for the adjustment, and, if known
at the time, the amount of the adjustment to be

18.

made. This record date may be the date on which the Purchase Price is adjusted
or any day thereafter, but, if the Right Certificates have been issued, shall be
at least 10 days later than the date of the public announcement. If Right
Certificates have been issued, upon each adjustment of the number of Rights
pursuant to this Section 11(i), the Company shall, as promptly as practicable,
cause to be distributed to holders of record of Right Certificates on such
record date Right Certificates evidencing, subject to Section 14 hereof, the
additional Rights to which such holders shall be entitled as a result of such
adjustment, or, at the option of the Company, shall cause to be distributed to
such holders of record in substitution and replacement for the Right
Certificates held by such holders prior to the date of adjustment, and upon
surrender thereof, if required by the Company, new Right Certificates evidencing
all the Rights to which such holders shall be entitled after such adjustment.
Right Certificates so to be distributed shall be issued, executed and
countersigned in the manner provided for herein and shall be registered in the
names of the holders of record of Right Certificates on the record date
specified in the public announcement.

(j) Irrespective of any adjustment or change in the Purchase Price or the
number of one one-hundredths of a Preferred Share issuable upon the exercise of
the Rights, the Right Certificates theretofore and thereafter issued may
continue to express the Purchase Price and the number of one one-hundredths of a
Preferred Share which were expressed in the initial Right Certificates issued
hereunder.

(k) Before taking any action that would cause an adjustment reducing the
Purchase Price below one one-hundredth of the then par value, if any, of the
Preferred Shares issuable upon exercise of the Rights, the Company shall take
any corporate action which may, in the opinion of its counsel, be necessary in
order that the Company may validly and legally issue fully paid and
nonassessable Preferred Shares at such adjusted Purchase Price.

(l) In any case in which this Section 11 shall require that an adjustment
in the Purchase Price be made effective as of a record date for a specified
event, the Company may elect to defer until the occurrence of such event the
issuing to the holder of any Right exercised after such record date of the
Preferred Shares and other capital stock or securities of the Company, if any,
issuable upon such exercise on the basis of the Purchase Price in effect prior
to such adjustment; PROVIDED, HOWEVER, that the Company shall deliver to such
holder a due ▇▇▇▇ or other appropriate instrument evidencing such holder's right
to receive such additional shares upon the occurrence of the event requiring
such adjustment.

(m) The Company covenants and agrees that, after the Distribution Date, it
will not, except as permitted by Section 23 or Section 27 hereof, take (or
permit any Subsidiary to take) any action the purpose of which is to, or if at
the time such action is

19.

taken it is reasonably foreseeable that the effect of such action is to,
materially diminish or eliminate the benefits intended to be afforded by the
Rights. Any action taken by the Company during any period after any Person
becomes an Acquiring Person but prior to the Distribution Date shall be null and
void unless such action could be taken under this Section 11(m) from and after
the Distribution Date.

(n) Anything in this Section 11 to the contrary notwithstanding, the
Company shall be entitled to make such reductions in the Purchase Price, in
addition to those adjustments expressly required by this Section 11, as and to
the extent that it in its sole discretion shall determine to be advisable in
order that any consolidation or subdivision of the Preferred Shares, issuance
wholly for cash of any Preferred Shares at less than the current market price,
issuance wholly for cash of Preferred Shares or securities which by their terms
are convertible into or exchangeable for Preferred Shares, dividends on
Preferred Shares payable in Preferred Shares or issuance of rights, options or
warrants referred to hereinabove in Section 11(b), hereafter made by the Company
to holders of its Preferred Shares shall not be taxable to such stockholders.

(o) In the event that at any time after the date of this Agreement and
prior to the Distribution Date, the Company shall (i) declare or pay any
dividend on the Common Shares payable in Common Shares or (ii) effect a
subdivision, combination or consolidation of the Common Shares (by
reclassification or otherwise than by payment of dividends in Common Shares)
into a greater or lesser number of Common Shares, then in any such case (A) the
number of one one-hundredths of a Preferred Share purchasable after such event
upon proper exercise of each Right shall be determined by multiplying the number
of one one-hundredths of a Preferred Share so purchasable immediately prior to
such event by a fraction, the numerator of which is the number of Common Shares
outstanding immediately before such event and the denominator of which is the
number of Common Shares outstanding immediately after such event, and (B) each
Common Share outstanding immediately after such event shall have issued with
respect to it that number of Rights which each Common Share outstanding
immediately prior to such event had issued with respect to it. The adjustments
provided for in this Section 11(o) shall be made successively whenever such a
dividend is declared or paid or such a subdivision, combination or consolidation
is effected.

(p) The exercise of Rights under Section 11(a)(ii) hereof shall only
result in the loss of rights under Section 11(a)(ii) hereof to the extent so
exercised and shall not otherwise affect the rights represented by the Rights
under this Agreement, including the rights represented by Section 13 hereof.

SECTION 12. CERTIFICATE OF ADJUSTED PURCHASE PRICE OR NUMBER OF SHARES.
Whenever an adjustment is made as provided in Sections 11 and 13 hereof, the
Company shall promptly (a) prepare a certificate setting forth such adjustment,
and a brief statement

20.

of the facts accounting for such adjustment, (b) file with the Rights Agent and
with each transfer agent for the Common Shares or the Preferred Shares a copy of
such certificate and (c) mail a brief summary thereof to each holder of a Right
Certificate in accordance with Section 25 hereof. The Rights Agent shall be
fully protected in relying on any such certificate and on any adjustment therein
contained and shall not be deemed to have knowledge of any adjustment unless and
until it shall have received such certificate.

SECTION 13. CONSOLIDATION, MERGER OR SALE OR TRANSFER OF ASSETS OR EARNING
POWER.

(a) In the event that, following the Shares Acquisition Date or, if a
Transaction is proposed, the Distribution Date, directly or indirectly (x) the
Company shall consolidate with, or merge with and into, any Interested
Stockholder, or if in such merger or consolidation all holders of Common Stock
are not treated alike, any other Person, (y) any Person shall consolidate with
the Company, or merge with and into the Company, and the Company shall be the
continuing or surviving corporation of such merger (other than, in the case of
either transaction described in (x) or (y), a merger or consolidation which
would result in all of the voting power represented by the securities of the
Company outstanding immediately prior thereto continuing to represent (either by
remaining outstanding or by being converted into securities of the surviving
entity) all of the voting power represented by the securities of the Company or
such surviving entity outstanding immediately after such merger or consolidation
and the holders of such securities not having changed as a result of such merger
or consolidation), or (z) the Company shall sell, mortgage or otherwise transfer
(or one or more of its subsidiaries shall sell, mortgage or otherwise transfer),
in one or more transactions, assets or earning power aggregating more than 50%
of the assets or earning power of the Company and its subsidiaries (taken as a
whole) to any Interested Stockholder or Stockholders, or if in such transaction
all holders of Common Stock are not treated alike, any other Person, (other than
the Company or any Subsidiary of the Company in one or more transactions each of
which individually and the aggregate does not violate Section 13(d) hereof)
then, and in each such case, proper provision shall be made so that (i) each
holder of a Right, subject to Section 11(a)(ii) hereof, shall have the right to
receive, upon the exercise thereof at a price equal to the then current Purchase
Price multiplied by the number of one one-hundredths of a Preferred Share for
which a Right is then exercisable in accordance with the terms of this Agreement
and in lieu of Preferred Shares, such number of freely tradeable Common Shares
of the Principal Party (as such term is hereinafter defined), free and clear of
liens, rights of call or first refusal, encumbrances or other adverse claims, as
shall be equal to the result obtained by (A) multiplying the then current
Purchase Price by the number of one one-hundredths of a Preferred Share for
which a Right is then exercisable (without taking into account any adjustment
previously made pursuant to Section 11(a)(ii) hereof) and dividing that product
by (B) 50% of the then current per share market price of the Common Shares of
such Principal Party (determined pursuant to

21.

Section 11(d) hereof) on the date of consummation of such consolidation, merger,
sale or transfer; (ii) such Principal Party shall thereafter be liable for, and
shall assume, by virtue of such consolidation, merger, sale or transfer, all the
obligations and duties of the Company pursuant to this Agreement; (iii) the term
"Company" shall thereafter be deemed to refer to such Principal Party, it being
specifically intended that the provisions of Section 11 hereof shall apply to
such Principal Party; and (iv) such Principal Party shall take such steps
(including, but not limited to, the reservation of a sufficient number of shares
of its Common Shares in accordance with Section 9 hereof) in connection with
such consummation as may be necessary to assure that the provisions hereof shall
thereafter be applicable, as nearly as reasonably may be, in relation to its
Common Shares thereafter deliverable upon the exercise of the Rights.

(b) "Principal Party" shall mean:

(i) in the case of any transaction described in clause (x) or
(y) of the first sentence of Section 13(a) hereof, the Person that is the issuer
of any securities into which Common Shares are converted in such merger or
consolidation, and if no securities are so issued, the Person that is the other
party to the merger or consolidation (or, if applicable, the Company, if it is
the surviving corporation); and

(ii) in the case of any transaction described in (z) of the first
sentence of Section 13(a) hereof, the Person that is the party receiving the
greatest portion of the assets or earning power transferred pursuant to such
transaction or transactions;

(1) if the Common Shares of such Person are not at such
time and have not been continuously over the preceding 12-month period
registered under Section 12 of the Exchange Act, and such Person is a direct or
indirect subsidiary or Affiliate of another Person the Common Shares of which
are and have been so registered, "Principal Party" shall refer to such other
Person; (2) if such Person is a subsidiary, directly or indirectly, or Affiliate
of more than one Person, the Common Shares of two or more of which are and have
been so registered, "Principal Party" shall refer to whichever of such Persons
is the issuer of the Common Shares having the greatest aggregate market value;
and (3) if such Person is owned, directly or indirectly, by a joint venture
formed by two or more Persons that are not owned, directly or indirectly, by the
same Person, the rules set forth in (1) and (2) above shall apply to each of the
chains of ownership having an interest in such joint venture as if such party
were a "subsidiary" of both or all of such joint venturers and the Principal
Parties in each such chain shall bear the obligations set forth in this
Section 13 in the same ratio as their direct or indirect interests in such
Person bear to the total of such interests.

(c) The Company shall not consummate any such consolidation, merger, sale
or transfer unless the Principal Party shall have a sufficient number of
authorized Common

22.

Shares that have not been issued or reserved for issuance to permit the exercise
in full of the Rights in accordance with this Section 13 and unless prior
thereto the Company and each Principal Party and each other Person who may
become a Principal Party as a result of such consolidation, merger, sale or
transfer shall have (i) executed and delivered to the Rights Agent a
supplemental agreement providing for the terms set forth in paragraphs (a) and
(b) of this Section 13 and (ii) prepared, filed and had declared and remain
effective a registration statement under the Act on the appropriate form with
respect to the Rights and the securities exercisable upon exercise of the Rights
and further providing that, as soon as practicable after the date of any
consolidation, merger, sale or transfer of assets mentioned in paragraph (a) of
this Section 13, the Principal Party at its own expense will:

(i) cause the registration statement under the Act with respect to
the Rights and the securities purchasable upon exercise of the Rights on an
appropriate form to remain effective (with a prospectus at all times meeting the
requirements of the Act) until the Final Expiration Date;

(iii) list the Rights and the securities purchasable upon exercise of
the Rights on each national securities exchange on which the Common Shares were
listed prior to the consummation of the Business Combination or on the Nasdaq
National Market if the Common Shares were listed on the Nasdaq National Market
or, if the Common Shares were not listed on a national securities exchange or
the Nasdaq National Market prior to the consummation of the Business
Combination, on a national securities exchange or the Nasdaq National Market;
and

(iv) deliver to holders of the Rights historical financial
statements for the Principal Party and each of its Affiliates which comply in
all material respects with the requirements for registration on Form 10 under
the Exchange Act.

The provisions of this Section 13 shall similarly apply to successive mergers or
consolidations or sales or other transfers.

(d) After the Distribution Date, the Company covenants and agrees that it
shall not (i) consolidate with, (ii) merge with or into, or (iii) sell or
transfer to, in one or more transactions, assets or earning power aggregating
more than 50% of the assets or earning power of the Company and its subsidiaries
taken as a whole, any other Person (other than a Subsidiary of the Company in a
transaction which does not violate Section 11(m) hereof), if (x) at the time of
or after such consolidation, merger or sale there are any charter or bylaw
provisions or any rights, warrants or other instruments or securities

23.

outstanding, agreements in effect or any other action taken which would diminish
or otherwise eliminate the benefits intended to be afforded by the Rights or (y)
prior to, simultaneously with or immediately after such consolidation, merger or
sale, the stockholders of the Person who constitutes, or would constitute, the
APrincipal Party@ for purposes of Section 13(a) hereof shall have received a
distribution of Rights previously owned by such Person or any of its Affiliates
and Associates. The Company shall not consummate any such consolidation,
merger, sale or transfer unless prior thereto the Company and such other Person
shall have executed and delivered to the Rights Agent a supplemental agreement
evidencing compliance with this Section 13(d).

SECTION 14. FRACTIONAL RIGHTS AND FRACTIONAL SHARES.

(a) The Company shall not be required to issue fractions of Rights or to
distribute Right Certificates which evidence fractional Rights. In lieu of such
fractional Rights, there shall be paid to the registered holders of the Right
Certificates with regard to which such fractional Rights would otherwise be
issuable, an amount in cash equal to the same fraction of the current market
value of a whole Right. For the purposes of this Section 14(a), the current
market value of a whole Right shall be the closing price of the Rights for the
Trading Day immediately prior to the date on which such fractional Rights would
have been otherwise issuable. The closing price for any day shall be the last
sale price, regular way, or, in case no such sale takes place on such day, the
average of the closing bid and asked prices, regular way, in either case as
reported in the principal consolidated transaction reporting system with respect
to securities listed or admitted to trading on the New York Stock Exchange or,
if the Rights are not listed or admitted to trading on the New York Stock
Exchange, as reported in the principal consolidated transaction reporting system
with respect to securities listed on the principal national securities exchange
on which the Rights are listed or admitted to trading or as reported on the
Nasdaq National Market or, if the Rights are not listed or admitted to trading
on any national securities exchange or reported on the Nasdaq National Market,
the last quoted price or, if not so quoted, the average of the high bid and low
asked prices in the over-the-counter market, as reported by Nasdaq or such other
system then in use or, if on any such date the Rights are not quoted by any such
organization, the average of the closing bid and asked prices as furnished by a
professional market maker making a market in the Rights selected by the Board of
Directors of the Company. If on any such date no such market maker is making a
market in the Rights, the fair value of the Rights on such date as determined in
good faith by the Board of Directors of the Company shall be used.

(b) The Company shall not be required to issue fractions of Preferred
Shares (other than fractions which are integral multiples of one one-hundredth
of a Preferred Share) upon exercise of the Rights or to distribute certificates
which evidence fractional Preferred Shares (other than fractions which are
integral multiples of one one-

24.

hundredth of a Preferred Share). Fractions of Preferred Shares in integral
multiples of one one-hundredth of a Preferred Share may, at the election of the
Company, be evidenced by depositary receipts; PROVIDED, HOWEVER, that holders of
such depositary receipts shall have all of the designations and the powers,
preferences and rights, and the qualifications, limitations and restrictions to
which they are entitled as beneficial owners of the Preferred Shares represented
by such depositary receipts. In lieu of fractional Preferred Shares that are
not integral multiples of one one-hundredth of a Preferred Share, the Company
shall pay to the registered holders of Right Certificates at the time such
Rights are exercised as herein provided an amount in cash equal to the same
fraction of the current market value of one Preferred Share. For the purposes
of this Section 14(b), the current market value of a Preferred Share shall be
the current per share market price of the Preferred Shares (as determined
pursuant to the second sentence of Section 11(d)(i) hereof) for the Trading Day
immediately prior to the date of such exercise (or, if not publicly traded, in
accordance with Section 11(d)(ii) hereof).

(c) Following the occurrence of one of the transactions or events
specified in Section 11 hereof giving rise to the right to receive Common
Shares, capital stock equivalents (other than Preferred Shares) or other
securities upon the exercise of a Right, the Company shall not be required to
issue fractions of Common Shares or units of such Common Shares, capital stock
equivalents or other securities upon exercise of the Rights or to distribute
certificates which evidence fractional Common Shares, capital stock equivalents
or other securities. In lieu of fractional Common Shares, capital stock
equivalents or other securities, the Company shall pay to the registered holders
of Right Certificates at the time such Rights are exercised as herein provided
an amount in cash equal to the same fraction of the current market value of one
Common Share or unit of such Common Shares, capital stock equivalents or other
securities. For purposes of this Section 14(c), the current market value shall
be the current per share market price (as determined pursuant to Section
11(d)(i) hereof) for the Trading Day immediately prior to the date of such
exercise and, if such capital stock equivalent is not traded, each such capital
stock equivalent shall have the value of one one-hundredth of a Preferred Share.

(d) The holder of a Right by the acceptance of the Right expressly waives
his right to receive any fractional Rights or any fractional shares upon
exercise of a Right (except as provided above).

SECTION 15. RIGHTS OF ACTION. All rights of action in respect of this
Agreement, excepting the rights of action given to the Rights Agent under
Sections 18 and 20 hereof, are vested in the respective registered holders of
the Right Certificates (and, prior to the Distribution Date, the registered
holders of the Common Shares) and any registered holder of any Right Certificate
(or, prior to the Distribution Date, of the Common Shares), without the consent
of the Rights Agent or of the holder of any other Right Certificate (or, prior
to the Distribution Date, of the Common Shares), may, in his own behalf and for
his own benefit, enforce, and may institute and maintain any suit, action or

25.

proceeding against the Company to enforce, or otherwise act in respect of, his
right to exercise the Rights evidenced by such Right Certificate in the manner
provided in such Right Certificate and in this Agreement. Without limiting the
foregoing or any remedies available to the holders of Rights, it is specifically
acknowledged that the holders of Rights would not have an adequate remedy at law
for any breach of this Agreement and will be entitled to specific performance of
the obligations under, and injunctive relief against actual or threatened
violations of the obligations of any Person subject to, this Agreement. Holders
of Rights shall be entitled to recover the reasonable costs and expenses,
including attorneys fees, incurred by them in any action to enforce the
provisions of this Agreement.

SECTION 16. AGREEMENT OF RIGHT HOLDERS. Every holder of a Right, by
accepting the same, consents and agrees with the Company and the Rights Agent
and with every other holder of a Right that:

(a) prior to the Distribution Date, the Rights will be transferable only
in connection with the transfer of the Common Shares;

(b) after the Distribution Date, the Right Certificates are transferable
(subject to the provisions of this Rights Agreement) only on the registry books
of the Rights Agent if surrendered at the principal office of the Rights Agent,
duly endorsed or accompanied by a proper instrument of transfer; and

(c) the Company and the Rights Agent may deem and treat the person in
whose name the Right Certificate (or, prior to the Distribution Date, the
associated Common Shares certificate) is registered as the absolute owner
thereof and of the Rights evidenced thereby (notwithstanding any notations of
ownership or writing on the Right Certificates or the associated Common Shares
certificate made by anyone other than the Company or the Rights Agent) for all
purposes whatsoever, and neither the Company nor the Rights Agent shall be
affected by any notice to the contrary.

SECTION 17. RIGHT CERTIFICATE HOLDER NOT DEEMED A STOCKHOLDER. No holder, as
such, of any Right Certificate shall be entitled to vote, receive dividends or
be deemed for any purpose the holder of the Preferred Shares or any other
securities of the Company which may at any time be issuable on the exercise of
the Rights represented thereby, nor shall anything contained herein or in any
Right Certificate be construed to confer upon the holder of any Right
Certificate, as such, any of the rights of a stockholder of the Company or any
right to vote for the election of directors or upon any matter submitted to
stockholders at any meeting thereof, or to give or withhold consent to any
corporate action, or to receive notice of meetings or other actions affecting
stockholders (except as provided in Section 25 hereof), or to receive dividends
or subscription rights,

26.

or otherwise, until the Right or Rights evidenced by such Right Certificate
shall have been exercised in accordance with the provisions hereof.

SECTION 18. CONCERNING THE RIGHTS AGENT. The Company agrees to pay to the
Rights Agent reasonable compensation for all services rendered by it hereunder
and, from time to time, on demand of the Rights Agent, its reasonable expenses
and counsel fees and other disbursements incurred in the administration and
execution of this Agreement and the exercise and performance of its duties
hereunder. The Company also agrees to indemnify the Rights Agent for, and to
hold it harmless against, any loss, liability, or expense, incurred without
negligence, bad faith or willful misconduct on the part of the Rights Agent, for
anything done or omitted by the Rights Agent in connection with the acceptance
and administration of this Agreement, including the costs and expenses of
defending against any claim of liability in the premises. The indemnity
provided herein shall survive the expiration of the Rights and the termination
of this Agreement.

The Rights Agent shall be protected and shall incur no liability for, or in
respect of any action taken, suffered or omitted by it in connection with, its
administration of this Agreement in reliance upon any Right Certificate or
certificate for the Preferred Shares or Common Shares or for other securities of
the Company, instrument of assignment or transfer, power of attorney,
endorsement, affidavit, letter, notice, direction, consent, certificate,
statement, or other paper or document believed by it to be genuine and to be
signed, executed and, where necessary, verified or acknowledged, by the proper
person or persons, or otherwise upon the advice of counsel as set forth in
Section 20 hereof.

SECTION 19. MERGER OR CONSOLIDATION OR CHANGE OF NAME OF RIGHTS AGENT. Any
corporation into which the Rights Agent or any successor Rights Agent may be
merged or with which it may be consolidated, or any corporation resulting from
any merger or consolidation to which the Rights Agent or any successor Rights
Agent shall be a party, or any corporation succeeding to the shareholder
services or corporate trust business of the Rights Agent or any successor Rights
Agent, shall be the successor to the Rights Agent under this Agreement without
the execution or filing of any paper or any further act on the part of any of
the parties hereto, provided that such corporation would be eligible for
appointment as a successor Rights Agent under the provisions of Section 21
hereof. In case at the time such successor Rights Agent shall succeed to the
agency created by this Agreement any of the Right Certificates shall have been
countersigned but not delivered, any such successor Rights Agent may adopt the
countersignature of the predecessor Rights Agent and deliver such Right
Certificates so countersigned; and in case at that time any of the Right
Certificates shall not have been countersigned, any successor Rights Agent may
countersign such Right Certificates either in the name of the predecessor Rights
Agent or in the name of the successor Rights Agent; and in all such cases such
Right Certificates shall have the full force provided in the Right Certificates
and in this Agreement.

27.

In case at any time the name of the Rights Agent shall be changed and at
such time any of the Right Certificates shall have been countersigned but not
delivered, the Rights Agent may adopt the countersignature under its prior name
and deliver Right Certificates so countersigned; and in case at that time any of
the Right Certificates shall not have been countersigned, the Rights Agent may
countersign such Right Certificates either in its prior name or in its changed
name; and in all such cases such Right Certificates shall have the full force
provided in the Right Certificates and in this Agreement.

SECTION 20. DUTIES OF RIGHTS AGENT. The Rights Agent undertakes the duties
and obligations imposed by this Agreement upon the following terms and
conditions, by all of which the Company and the holders of Right Certificates,
by their acceptance thereof, shall be bound:

(a) The Rights Agent may consult with legal counsel of its choice (who may
be legal counsel for the Company), and the opinion of such counsel shall be full
and complete authorization and protection to the Rights Agent as to any action
taken or omitted by it in good faith and in accordance with such opinion.

(b) Whenever in the performance of its duties under this Agreement the
Rights Agent shall deem it necessary or desirable that any fact or matter be
proved or established by the Company prior to taking or suffering any action
hereunder, such fact or matter (unless other evidence in respect thereof be
herein specifically prescribed) may be deemed to be conclusively proved and
established by a certificate signed by any one of the Chairman of the Board, the
Chief Executive Officer, the President, the Chief Financial Officer, any Vice
President, the Treasurer or the Secretary of the Company and delivered to the
Rights Agent; and such certificate shall be full authorization to the Rights
Agent for any action taken or suffered in good faith by it under the provisions
of this Agreement in reliance upon such certificate.

(c) The Rights Agent shall be liable hereunder to the Company and any
other Person only for its own negligence, bad faith or willful misconduct.

(d) The Rights Agent shall not be liable for or by reason of any of the
statements of fact or recitals contained in this Agreement or in the Right
Certificates (except its countersignature thereof) or be required to verify the
same, but all such statements and recitals are and shall be deemed to have been
made by the Company only.

(e) The Rights Agent shall not be under any responsibility in respect of
the validity of this Agreement or the execution and delivery hereof (except the
due execution hereof by the Rights Agent) or in respect of the validity or
execution of any Right Certificate (except its countersignature thereof); nor
shall it be responsible for any breach by the Company of any covenant or
condition contained in this Agreement or in any

28.

Right Certificate; nor shall it be responsible for any change in the
exercisability of the Rights (including the Rights becoming void pursuant to
Section 11(a)(ii) hereof) or any adjustment in the terms of the Rights
(including the manner, method or amount thereof) provided for in Sections 3, 11,
13, 23 or 24 hereof, or the ascertaining of the existence of facts that would
require any such change or adjustment (except with respect to the exercise of
Rights evidenced by Right Certificates after receipt of a certificate pursuant
to Section 12 hereof describing such change or adjustment); nor shall it by any
act hereunder be deemed to make any representation or warranty as to the
authorization or reservation of any Preferred Shares to be issued pursuant to
this Agreement or any Right Certificate or as to whether any Preferred Shares
will, when issued, be validly authorized and issued, fully paid and
nonassessable.

(f) The Company agrees that it will perform, execute, acknowledge and
deliver or cause to be performed, executed, acknowledged and delivered all such
further and other acts, instruments and assurances as may reasonably be required
by the Rights Agent for the carrying out or performing by the Rights Agent of
the provisions of this Agreement.

(g) The Rights Agent is hereby authorized and directed to accept
instructions with respect to the performance of its duties hereunder from any
one of the Chairman of the Board, the Chief Executive Officer, the President,
the Chief Financial Officer, any Vice President, the Secretary or the Treasurer
of the Company, and to apply to such officers for advice or instructions in
connection with its duties, and it shall not be liable for any action taken or
suffered by it in good faith in accordance with instructions of any such officer
or for any delay in acting while waiting for those instructions. Any
application by the Rights Agent for written instructions from the Company may,
at the option of the Rights Agent, set forth in writing any action proposed to
be taken or omitted by the Rights Agent with respect to its duties or
obligations under this Agreement and the date on and/or after which such action
shall be taken or omitted and the Rights Agent shall not be liable for any
action taken or omitted in accordance with a proposal included in any such
application on or after the date specified therein (which date shall not be less
than three business days after the date indicated in such application unless any
such officer shall have consented in writing to an earlier date) unless, prior
to taking or omitting any such action, the Rights Agent has received written
instructions in response to such application specifying the action to be taken
or omitted.

(h) The Rights Agent and any stockholder, director, officer or employee of
the Rights Agent may buy, sell or deal in any of the Rights or other securities
of the Company or become pecuniarily interested in any transaction in which the
Company may be interested, or contract with or lend money to the Company or
otherwise act as fully and freely as though it were not Rights Agent under this
Agreement. Nothing herein shall

29.

preclude the Rights Agent from acting in any other capacity for the Company or
for any other legal entity.

(i) The Rights Agent may execute and exercise any of the rights or powers
hereby vested in it or perform any duty hereunder either itself or by or through
its attorneys or agents, and the Rights Agent shall not be answerable or
accountable for any act, default, neglect or misconduct of any such attorneys or
agents or for any loss to the Company resulting from any such act, default,
neglect or misconduct, provided reasonable care was exercised in the selection
and continued employment thereof.

(j) No provision of this Agreement shall require the Rights Agent to
expend or risk its own funds or otherwise incur any financial liability in the
performance of any of its duties hereunder or in the exercise of its rights if
there shall be reasonable grounds for believing that repayment of such funds or
adequate indemnification against such risk or liability is not reasonably
assured to it.

(k) If, with respect to any Right Certificate surrendered to the Rights
Agent for exercise or transfer, the certificate attached to the form of
assignment or form of election to purchase, as the case may be, has not been
executed, the Rights Agent shall not take any further action with respect to
such requested exercise of transfer without first consulting with the Company.

SECTION 21. CHANGE OF RIGHTS AGENT. The Rights Agent or any successor Rights
Agent may resign and be discharged from its duties under this Agreement upon 30
days' notice in writing mailed to the Company and to each transfer agent for the
Common Shares or Preferred Shares by registered or certified mail, and to the
holders of the Right Certificates by first-class mail. The Company may remove
the Rights Agent or any successor Rights Agent upon 30 days' notice in writing,
mailed to the Rights Agent or successor Rights Agent, as the case may be, and to
each transfer agent for the Common Shares or Preferred Shares by registered or
certified mail, and to the holders of the Right Certificates by first-class
mail. If the Rights Agent shall resign or be removed or shall otherwise become
incapable of acting, the Company shall appoint a successor to the Rights Agent.
If the Company shall fail to make such appointment within a period of 30 days
after giving notice of such removal or after it has been notified in writing of
such resignation or incapacity by the resigning or incapacitated Rights Agent or
by the holder of a Right Certificate (who shall, with such notice, submit his
Right Certificate for inspection by the Company), then the registered holder of
any Right Certificate may apply to any court of competent jurisdiction for the
appointment of a new Rights Agent. Any successor Rights Agent, whether
appointed by the Company or by such a court, shall be a corporation organized
and doing business under the laws of the United States or of any other state of
the United States which is authorized under such laws to exercise corporate
trust or stock transfer powers and is subject to supervision or examination by

30.

federal or state authority and which has at the time of its appointment as
Rights Agent a combined capital and surplus of at least $50 million. After
appointment, the successor Rights Agent shall be vested with the same powers,
rights, duties and responsibilities as if it had been originally named as Rights
Agent without further act or deed; but the predecessor Rights Agent shall
deliver and transfer to the successor Rights Agent any property at the time held
by it hereunder, and execute and deliver any further assurance, conveyance, act
or deed necessary for the purpose. Not later than the effective date of any
such appointment the Company shall file notice thereof in writing with the
predecessor Rights Agent and each transfer agent for the Common Shares or
Preferred Shares, and mail a notice thereof in writing to the registered holders
of the Right Certificates. Failure to give any notice provided for in this
Section 21, however, or any defect therein, shall not affect the legality or
validity of the resignation or removal of the Rights Agent or the appointment of
the successor Rights Agent, as the case may be.

SECTION 22. ISSUANCE OF NEW RIGHT CERTIFICATES. Notwithstanding any of the
provisions of this Agreement or of the Rights to the contrary, the Company may,
at its option, issue new Right Certificates evidencing Rights in such form as
may be approved by its Board of Directors to reflect any adjustment or change in
the Purchase Price and the number or kind or class of shares or other securities
or property purchasable under the Right Certificates made in accordance with the
provisions of this Agreement. In addition, in connection with the issuance or
sale of Common Shares following the Distribution Date and prior to the earlier
of the Redemption Date and the Final Expiration Date, the Company (a) shall with
respect to Common Shares so issued or sold pursuant to the exercise of stock
options or under any employee plan or arrangement in existence prior to the
Distribution Date, or upon the exercise, conversion or exchange of securities,
notes or debentures issued by the Company and in existence prior to the
Distribution Date, and (b) may, in any other case, if deemed necessary or
appropriate by the Board of Directors of the Company, issue Right Certificates
representing the appropriate number of Rights in connection with such issuance
or sale; PROVIDED, HOWEVER, that (i) the Company shall not be obligated to issue
any such Right Certificates if, and to the extent that, the Company shall be
advised by counsel that such issuance would create a significant risk of
material adverse tax consequences to the Company or the Person to whom such
Right Certificate would be issued, and (ii) no Right Certificate shall be issued
if, and to the extent that, appropriate adjustment shall otherwise have been
made in lieu of the issuance thereof.

SECTION 23. REDEMPTION.

(a) The Rights may be redeemed by action of the Board of Directors
pursuant to Section 23(b) hereof and shall not be redeemed in any other manner.

(b) (i) The Board of Directors of the Company may, at its option, at
any time prior to the earlier of such time as any Person becoming an Acquiring
Person or the

31.

Final Expiration Date, redeem all but not less than all of the then outstanding
Rights at a redemption price of $.001 per Right, appropriately adjusted to
reflect any stock split, stock dividend or similar transaction occurring after
the date hereof (such redemption price being hereinafter referred to as the
"Redemption Price"), and the Company may, at its option, pay the Redemption
Price in Common Shares (based on the "current per share market price," as such
term is defined in Section 11(d) hereof, of the Common Shares at the time of
redemption), cash or any other form of consideration deemed appropriate by the
Board of Directors. The redemption of the Rights by the Board of Directors may
be made effective at such time, on such basis and subject to such conditions as
the Board of Directors in its sole discretion may establish. Notwithstanding
anything contained in this Agreement to the contrary, the Rights shall not be
exercisable pursuant to Section 11(a)(ii) hereof prior to the expiration or
termination of the Company's right of redemption under this Section 23(b)(i).

(ii) In addition, the Board of Directors of the Company may, at its
option, at any time after the time a Person becomes an Acquiring Person and the
expiration of any period during which the holder of Rights may exercise the
rights under Section 11(a)(ii) hereof but prior to any event described in clause
(x), (y) or (z) of the first sentence of Section 13 hereof, redeem all but not
less than all of the then outstanding Rights at the Redemption Price (x) in
connection with any merger, consolidation or sale or other transfer (in one
transaction or in a series of related transactions) of assets or earning power
aggregating 50% or more of the assets or earning power of the Company and its
subsidiaries (taken as a whole) in which all holders of Common Shares are
treated alike and not involving (other than as a holder of Common Shares being
treated like all other such holders) an Interested Stockholder or a Transaction
Person or (y)(A) if and for so long as the Acquiring Person is not thereafter
the Beneficial Owner of 20% or more of the then outstanding Common Shares, and
(B) at the time of redemption no other Persons are Acquiring Persons.

(c) Immediately upon the action of the Board of Directors of the Company
ordering the redemption of the Rights pursuant to Section 23(b) hereof, and
without any further action and without any notice, the right to exercise the
Rights will terminate and the only right thereafter of the holders of Rights
shall be to receive the Redemption Price. The Company shall promptly give
public notice of any such redemption; PROVIDED, HOWEVER, that the failure to
give, or any defect in, any such notice shall not affect the validity of such
redemption. Within 10 days after such action of the Board of Directors ordering
the redemption of the Rights pursuant to Section 23(b) hereof, the Company shall
mail a notice of redemption to all the holders of the then outstanding Rights at
their last addresses as they appear upon the registry books of the Rights Agent
or, prior to the Distribution Date, on the registry books of the transfer agent
for the Common Shares, PROVIDED, HOWEVER, that failure to give, or any defect
in, any such notice shall not affect the validity of such redemption. Any
notice which is mailed in the manner herein

32.

provided shall be deemed given, whether or not the holder receives the notice.
Each such notice of redemption will state the method by which the payment of the
Redemption Price will be made. Neither the Company nor any of its Affiliates or
Associates may redeem, acquire or purchase for value any Rights at any time in
any manner other than that specifically set forth in this Section 23 or in
Section 24 hereof, and other than in connection with the purchase of Common
Shares prior to the Distribution Date.

(d) The Company may, at its option, discharge all of its obligations with
respect to any redemption of the Rights by (i) issuing a press release
announcing the manner of redemption of the Rights and (ii) mailing payment of
the Redemption Price to the registered holders of the Rights at their last
addresses as they appear on the registry books of the Rights Agent or, prior to
the Distribution Date, on the registry books of the transfer agent for the
Common Shares, and upon such action, all outstanding Right Certificates shall be
null and void without any further action by the Company.

SECTION 24. EXCHANGE.

(a) The Board of Directors of the Company may, at its option, at any time
after any Person becomes an Acquiring Person, exchange all or part of the then
outstanding and exercisable Rights (which shall not include Rights that have
become void pursuant to the provisions of Section 11(a)(ii) hereof) for Common
Shares at an exchange ratio of one Common Share per Right, appropriately
adjusted to reflect any stock split, stock dividend or similar transaction
occurring after the date hereof (such exchange ratio being hereinafter referred
to as the "Exchange Ratio"). Notwithstanding the foregoing, the Board of
Directors shall not be empowered to effect such exchange at any time after any
Person (other than the Company, any Subsidiary of the Company, any employee
benefit plan of the Company or any such Subsidiary, or any entity holding Common
Shares for or pursuant to the terms of any such plan), together with all
Affiliates and Associates of such Person, becomes the Beneficial Owner of 50% or
more of the Common Shares then outstanding.

(b) Immediately upon the action of the Board of Directors of the Company
ordering the exchange of any Rights pursuant to Section 24(a) hereof and without
any further action and without any notice, the right to exercise such Rights
shall terminate and the only right thereafter of a holder of such Rights shall
be to receive that number of Common Shares equal to the number of such Rights
held by such holder multiplied by the Exchange Ratio. The Company shall
promptly give public notice of any such exchange; PROVIDED, HOWEVER, that the
failure to give, or any defect in, such notice shall not affect the validity of
such exchange. The Company promptly shall mail a notice of any such exchange to
all of the holders of such Rights at their last addresses as they appear upon
the registry books of the Rights Agent; PROVIDED, HOWEVER, that the failure to
give, or any defect in, such notice shall not affect the validity of such
exchange. Any notice which is

33.

mailed in the manner herein provided shall be deemed given, whether or not the
holder receives the notice. Each such notice of exchange will state the method
by which the exchange of the Common Shares for Rights will be effected and, in
the event of any partial exchange, the number of Rights which will be exchanged.
Any partial exchange shall be effected pro rata based on the number of Rights
(other than Rights which have become void pursuant to the provisions of
Section 11(a)(ii) hereof) held by each holder of Rights.

(c) In lieu of issuing Common Shares in accordance with Section 24(a)
hereof, the Company may, if a majority of the Board of Directors then in office
determines that such action is necessary or appropriate and not contrary to the
interests of the holders of Rights, elect to (and, in the event that there are
not sufficient treasury shares and authorized but unissued Common Shares to
permit any exchange of the Rights in accordance with Section 24(a) hereof, the
Company shall) take all such action as may be necessary to authorize, issue or
pay, upon the exchange of the Rights, cash (including by way of a reduction of
the Purchase Price), property, Common Shares, other securities or any
combination thereof having an aggregate value equal to the value of the Common
Shares which otherwise would have been issuable pursuant to Section 24(a)
hereof, which aggregate value shall be determined by a nationally recognized
investment banking firm selected by a majority of the Board of Directors then in
office. For purposes of the preceding sentence, the value of the Common Shares
shall be determined pursuant to Section 11(d) hereof. Any election pursuant to
this Section 24(c) by the Board of Directors must be made within 60 days
following the date on which the event described in Section 11(a)(ii) hereof
shall have occurred. Following the occurrence on the event described in Section
11(a)(ii) hereof, a majority of the Board of Directors then in office may
suspend the exercisability of the Rights for a period of up to 60 days following
the date on which the event described in Section 11(a)(ii) hereof shall have
occurred to the extent that such directors have not determined whether to
exercise their rights of election under this Section 24(c). In the event of any
such suspension, the Company shall issue a public announcement stating that the
exercisability of the Rights has been temporarily suspended.

(d) The Company shall not be required to issue fractions of Common Shares
or to distribute certificates which evidence fractional Common Shares. In lieu
of such fractional Common Shares, the Company shall pay to the registered
holders of the Right Certificates with regard to which such fractional Common
Shares would otherwise be issuable an amount in cash equal to the same fraction
of the current market value of a whole Common Share. For the purposes of this
Section 24(d), the current market value of a whole Common Share shall be the
closing price of a Common Share (as determined pursuant to the second sentence
of Section 11(d)(i) hereof) for the Trading Day immediately after the date of
the first public announcement by the Company that an exchange is to be effected
pursuant to this Section 24.

34.

(e) The Company shall not be required to issue fractions of Preferred
Shares (other than fractions which are integral multiples of one one-hundredth
of a Preferred Share) upon exchange of the Rights or to distribute certificates
which evidence fractional Preferred Shares (other than fractions which are
integral multiples of one one-hundredth of a Preferred Share). Fractions of
Preferred Shares in integral multiples of one one-hundredth of a Preferred Share
may, at the election of the Company, be evidenced by depositary receipts;
PROVIDED, HOWEVER, that holders of such depositary receipts shall have all of
the designations and the powers, preferences and rights, and the qualifications,
limitations and restrictions to which they are entitled as beneficial owners of
the Preferred Shares represented by such depositary receipts. In lieu of
fractional Preferred Shares that are not integral multiples of one one-hundredth
of a Preferred Share, the Company shall pay to the registered holders of Right
Certificates at the time such Rights are exercised as herein provided an amount
in cash equal to the same fraction of the current market value of one Preferred
Share. For the purposes of this Section 24(e), the current market value of a
Preferred Share shall be 100 times the closing price of a Common Share (as
determined pursuant to the second sentence of Section 11(d)(i) hereof) for the
Trading Day immediately after the date of the first public announcement by the
Company that an exchange is to be effected pursuant to this Section 24.

SECTION 25. NOTICE OF CERTAIN EVENTS.

(a) In case the Company shall propose (i) to pay any dividend payable in
stock of any class to the holders of its Preferred Shares or to make any other
distribution to the holders of its Preferred Shares (other than a regular
quarterly cash dividend), (ii) to offer to the holders of its Preferred Shares
rights or warrants to subscribe for or to purchase any additional Preferred
Shares or shares of stock of any class or any other securities, rights or
options, (iii) to effect any reclassification of its Preferred Shares (other
than a reclassification involving only the subdivision of outstanding Preferred
Shares), (iv) to effect any consolidation or merger into or with, or to effect
any sale or other transfer (or to permit one or more of its Subsidiaries to
effect any sale or other transfer), in one or more transactions, of 50% or more
of the assets or earning power of the Company and its Subsidiaries (taken as a
whole), to any other Person, (v) to effect the liquidation, dissolution or
winding up of the Company, or (vi) to declare or pay any dividend on the Common
Shares payable in Common Shares or to effect a subdivision, combination or
consolidation of the Common Shares (by reclassification or otherwise than by
payment of dividends in Common Shares), then, in each such case, the Company
shall give to each holder of a Right Certificate, in accordance with Section 26
hereof, a notice of such proposed action, which shall specify the record date
for the purpose of such stock dividend, or distribution of rights or warrants,
or the date on which such reclassification, consolidation, merger, sale,
transfer, liquidation, dissolution, or winding up is to take place and the date
of participation therein by the holders of the Common Shares and/or the
Preferred Shares, if any such date is to be fixed, and such notice shall be so
given in

35.

the case of any action covered by clause (i) or (ii) above at least 10 days
prior to the record date for determining holders of the Preferred Shares for
purposes of such action, and in the case of any such other action, at least 10
days prior to the date of the taking of such proposed action or the date of
participation therein by the holders of the Common Shares and/or the Preferred
Shares, whichever shall be the earlier.

(b) In case the event set forth in Section 11(a)(ii) hereof shall occur,
then the Company shall as soon as practicable thereafter give to each holder of
a Right Certificate, in accordance with Section 26 hereof, a notice of the
occurrence of such event, which notice shall describe the event and the
consequences of the event to holders of Rights under Section 11(a)(ii) hereof.

SECTION 26. NOTICES. Notices or demands authorized by this Agreement to be
given or made by the Rights Agent or by the holder of any Right Certificate to
or on the Company shall be sufficiently given or made if sent by first-class
mail, postage prepaid, addressed (until another address is filed in writing with
the Rights Agent) as follows:

CORVAS INTERNATIONAL, INC.
▇▇▇▇ ▇▇▇▇▇▇▇ ▇▇▇▇ ▇▇▇▇
▇▇▇ ▇▇▇▇▇, ▇▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇
ATTENTION: INVESTOR RELATIONS

Subject to the provisions of Section 21 hereof, any notice or demand authorized
by this Agreement to be given or made by the Company or by the holder of any
Right Certificate to or on the Rights Agent shall be sufficiently given or made
if sent by first-class mail, postage prepaid, addressed (until another address
is filed in writing with the Company) as follows:

AMERICAN STOCK TRANSFER AND TRUST COMPANY
▇▇ ▇▇▇▇ ▇▇▇▇▇▇
▇▇▇ ▇▇▇▇, ▇▇▇ ▇▇▇▇ ▇▇▇▇▇
ATTENTION: ▇▇▇▇▇ ▇▇▇▇▇▇

Notices or demands authorized by this Agreement to be given or made by the
Company or the Rights Agent to the holder of any Right Certificate shall be
sufficiently given or made if sent by first-class mail, postage prepaid,
addressed to such holder at the address of such holder as shown on the registry
books of the Company.

SECTION 27. SUPPLEMENTS AND AMENDMENTS. Prior to the Distribution Date, the
Company and the Rights Agent shall, if the Company so directs, supplement or
amend any provision of this Agreement without the approval of any holders of the
Rights. From and after the Distribution Date, the Company and the Rights Agent
shall, if the Company so directs, from time to time supplement or amend any
provision of this Agreement

36.

without the approval of any holders of Right Certificates in order to (i) cure
any ambiguity, (ii) correct or supplement any provision contained herein which
may be defective or inconsistent with any other provisions herein, or (iii)
change any other provisions with respect to the Rights which the Company may
deem necessary or desirable; PROVIDED, HOWEVER, that no such supplement or
amendment shall be made which would adversely affect the interests of the
holders of Rights (other than the interests of an Acquiring Person or its
Affiliates or Associates). Any supplement or amendment adopted during any
period after any Person has become an Acquiring Person but prior to the
Distribution Date shall become null and void unless such supplement or amendment
could have been adopted by the Company from and after the Distribution Date.
Any such supplement or amendment shall be evidenced by a writing signed by the
Company and the Rights Agent. Upon delivery of a certificate from an
appropriate officer of the Company which states that the proposed supplement or
amendment is in compliance with the terms of this Section 27, the Rights Agent
shall execute such supplement or amendment unless the Rights Agent shall have
determined in good faith that such supplement or amendment would adversely
affect its interest under this Agreement. Prior to the Distribution Date, the
interests of the holders of Rights shall be deemed coincident with the interests
of the holders of Common Shares.

SECTION 28. DETERMINATION AND ACTIONS BY THE BOARD OF DIRECTORS, ETC. For
all purposes of this Agreement, any calculation of the number of Common Shares
outstanding at any particular time, including for purposes of determining the
particular percentage of such outstanding Common Shares or any other securities
of which any Person is the Beneficial Owner, shall be made in accordance with
the last sentence of Rule 13d-3(d)(1)(i) of the General Rules and Regulations
under the Exchange Act as in effect on the date of this Agreement. The Board of
Directors of the Company shall have the exclusive power and authority to
administer this Agreement and to exercise all rights and powers specifically
granted to the Board, or the Company, or as may be necessary or advisable in the
administration of this Agreement, including without limitation, the right and
power to (i) interpret the provisions of this Agreement, and (ii) make all
determinations deemed necessary or advisable for the administration of this
Agreement (including a determination to redeem or not redeem the Rights or to
amend the Agreement). All such actions, calculations, interpretations and
determinations (including, for purposes of clause (y) below, all omissions with
respect to the foregoing) which are done or made by the Board in good faith,
shall (x) be final, conclusive and binding on the Rights Agent and the holders
of the Rights, and (y) not subject the Board to any liability to the holders of
the Rights.

SECTION 29. SUCCESSORS. All the covenants and provisions of this Agreement
by or for the benefit of the Company or the Rights Agent shall bind and inure to
the benefit of their respective successors and assigns hereunder.

37.

SECTION 30. BENEFITS OF THIS AGREEMENT. Nothing in this Agreement shall be
construed to give to any person or corporation other than the Company, the
Rights Agent and the registered holders of the Right Certificates (and, prior to
the Distribution Date, the Common Shares) any legal or equitable right, remedy
or claim under this Agreement; but this Agreement shall be for the sole and
exclusive benefit of the Company, the Rights Agent and the registered holders of
the Right Certificates (and, prior to the Distribution Date, the Common Shares).

SECTION 31. SEVERABILITY. If any term, provision, covenant or restriction of
this Agreement is held by a court of competent jurisdiction or other authority
to be invalid, void or unenforceable, the remainder of the terms, provisions,
covenants and restrictions of this Agreement shall remain in full force and
effect and shall in no way be affected, impaired or invalidated.

SECTION 32. GOVERNING LAW. This Agreement and each Right Certificate issued
hereunder shall be deemed to be a contract made under the laws of the State of
Delaware and for all purposes shall be governed by and construed in accordance
with the laws of such State applicable to contracts to be made and performed
entirely within such State.

SECTION 33. COUNTERPARTS. This Agreement may be executed in any number of
counterparts and each of such counterparts shall for all purposes be deemed to
be an original, and all such counterparts shall together constitute but one and
the same instrument.

SECTION 34. DESCRIPTIVE HEADINGS. Descriptive headings of the several
Sections of this Agreement are inserted for convenience only and shall not
control or affect the meaning or construction of any of the provisions hereof.

38.

IN WITNESS WHEREOF, parties whereto have caused this Agreement to be duly
executed, all as of the day and year first above written.

ATTEST: CORVAS INTERNATIONAL, INC.

/s/ /s/
----------------------------------- ----------------------------------------
▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇
Secretary President and Chief Executive Officer

ATTEST: AMERICAN STOCK TRANSFER AND
TRUST COMPANY

By: /s/ ▇▇▇▇▇ ▇▇▇▇▇▇ By: /s/ ▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇
-------------------------------- -------------------------------------
Title: Assistant Secretary Title: Vice President
----------------------------- ----------------------------------

EXHIBIT A

FORM OF

CERTIFICATE OF DESIGNATION

SERIES C JUNIOR PARTICIPATING PREFERRED STOCK

CORVAS INTERNATIONAL, INC.

(Pursuant to Section 151 of the
Delaware General Corporation Law)

CORVAS INTERNATIONAL, INC., a corporation organized and existing under the
General Corporation Law of the State of Delaware (hereinafter called the
"Company"), hereby certifies that the following resolution was adopted by the
Board of Directors of the Company as required by Section 151 of the General
Corporation Law at a meeting duly called and held on September 18, 1997:

RESOLVED, that pursuant to the authority granted to and vested in the
Board of Directors of the Company in accordance with the provisions of its
Certificate of Incorporation, the Board of Directors hereby creates a
series of Preferred Stock, par value $.001 per share, of the Company and
hereby states the designation and number of shares, and fixes the relative
designations and the powers, preferences and rights, and the
qualifications, limitations and restrictions thereof (in addition to the
provisions set forth in the Certificate of Incorporation of the Company,
which are applicable to the Preferred Stock of all classes and series), as
follows:

A-1.

Series C Junior Participating Preferred Stock:

SECTION 1. DESIGNATION AND AMOUNT. Five Hundred Thousand
(500,000) 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 conversion of
Series A Convertible Preferred Stock, par value $.001 per share (the
"Series A Preferred"), and Series B Convertible Preferred Stock, par value
$.001 per share (the "Series B Preferred"), or upon the conversion of any
outstanding securities issued by the Company convertible into Series C
Preferred.

SECTION 2. DIVIDENDS AND DISTRIBUTIONS.

(A) Subject to the payment in full of all accrued dividends to the
holders of Series A Preferred and Series B Preferred and subject to the
rights of such holders and of 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, not the Series A Preferred or the Series B Preferred), 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

A-2.

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.

(B) 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.

(C) 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.

A-3.

SECTION 3. VOTING RIGHTS. The holders of shares of Series C
Preferred shall have the following voting rights:

(A) 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.

(B) Except as otherwise provided herein, in the Certificate of
Designation creating the Series A Preferred, the Certificate of Designation
creating the Series B Preferred or 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 Series A
Preferred, the Series B Preferred and 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.

(C) 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 Series A Preferred, the Series B Preferred and the
Common Stock as set forth herein) for taking any corporate action.

SECTION 4. CERTAIN RESTRICTIONS.

(A) 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-4.

(i) 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;

(ii) 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;

(iii) 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

(iv) 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.

(B) 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.

SECTION 5. 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 Certificate of Incorporation, the Certificate of
Designation creating the Series A Preferred, the Certificate of Designation
creating the Series B Preferred or in any other

A-5.

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

SECTION 6. LIQUIDATION, DISSOLUTION OR WINDING UP. Subject to the
payment in full of the liquidation preferences of any outstanding Series A
Preferred and Series B Preferred and the rights of the holders of Series A
Preferred and Series B Preferred or 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.

SECTION 7. CONSOLIDATION, MERGER, ETC. Subject to the rights of
the holders of Series A Preferred and Series B Preferred, 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,

A-6.

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.

SECTION 8. NO REDEMPTION. The shares of Series C Preferred shall
not be redeemable.

SECTION 9. RANK. The Series C Preferred shall rank, with respect
to the payment of dividends and the distribution of assets, junior to the
Series A Preferred, the Series B Preferred and all series of any other
class of the Company's Preferred Stock.

SECTION 10. AMENDMENT. The 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.

A-7.

IN WITNESS WHEREOF, the undersigned have executed this certificate as of
September 18, 1997.

CORVAS INTERNATIONAL, INC.

----------------------------------------
▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇
President and Chief Executive Officer

----------------------------------------
▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇
Secretary

A-8.

EXHIBIT B

FORM OF RIGHT CERTIFICATE

CERTIFICATE NO. R- _____ RIGHTS

NOT EXERCISABLE AFTER SEPTEMBER 18, 2007 OR EARLIER IF REDEMPTION OR
EXCHANGE OCCURS. THE RIGHTS ARE SUBJECT TO REDEMPTION AT $.001 PER
RIGHT AND TO EXCHANGE ON THE TERMS SET FORTH IN THE RIGHTS AGREEMENT.

RIGHT CERTIFICATE

CORVAS INTERNATIONAL, INC.

This certifies that ___________________ or registered assigns, is the
registered owner of the number of Rights set forth above, each of which entitles
the owner thereof, subject to the terms, provisions and conditions of the Rights
Agreement, dated as of September 18, 1997 (the "Rights Agreement"), between
CORVAS INTERNATIONAL, INC., a Delaware corporation (the "Company"), and AMERICAN
STOCK TRANSFER AND TRUST COMPANY (the "Rights Agent"), to purchase from the
Company at any time after the Distribution Date (as such term is defined in the
Rights Agreement) and prior to 5:00 P.M., Pacific Time, on September 18, 2007 at
the office of the Rights Agent designated for such purpose, or at the office of
its successor as Rights Agent, one one-hundredth of a fully paid non-assessable
share of Series C Junior Participating Preferred Stock, par value $.001 per
share (the "Preferred Shares"), of the Company, at a purchase price of $50.00
per one one-hundredth of a Preferred Share (the "Purchase Price"), upon
presentation and surrender of this Right Certificate with the Form of Election
to Purchase duly executed. The number of Rights evidenced by this Right
Certificate (and the number of one one-hundredths of a Preferred Share which may
be purchased upon exercise hereof) set forth above, and the Purchase Price set
forth above, are the number and Purchase Price as of September 18, 1997, based
on the Preferred Shares as constituted at such date.

From and after the time any Person becomes an Acquiring Person (as such
terms are defined in the Rights Agreement), if the Rights evidenced by this
Right Certificate are beneficially owned by (i) an Acquiring Person or an
Affiliate or Associate of any such Acquiring Person (as such terms are defined
in the Rights Agreement), (ii) a transferee of any such Acquiring Person,
Associate or Affiliate who becomes a transferee after the Acquiring Person
becomes such, or (iii) under certain circumstances specified in the

B-1

Rights Agreement, a transferee of any such Acquiring Person, Associate or
Affiliate who becomes a transferee prior to or concurrently with the Acquiring
Person becoming such, such Rights shall become null and void without any further
action and no holder hereof shall have any right with respect to such Rights
from and after the time any Person becomes an Acquiring Person.

As provided in the Rights Agreement, the Purchase Price and the number of
one one-hundredths of a Preferred Share which may be purchased upon the exercise
of the Rights evidenced by this Right Certificate are subject to modification
and adjustment upon the happening of certain events.

This Right Certificate is subject to all of the terms, provisions and
conditions of the Rights Agreement, as amended from time to time, which terms,
provisions and conditions are hereby incorporated herein by reference and made a
part hereof and to which Rights Agreement reference is hereby made for a full
description of the rights, limitations of rights, obligations, duties and
immunities hereunder of the Rights Agent, the Company and the holders of the
Right Certificates. Copies of the Rights Agreement are on file at the principal
executive offices of the Company and the above-mentioned offices of the Rights
Agent.

This Right Certificate, with or without other Right Certificates, upon
surrender at the office of the Rights Agent designated for such purpose, may be
exchanged for another Right Certificate or Right Certificates of like tenor and
date evidencing Rights entitling the holder to purchase a like aggregate number
of Preferred Shares as the Rights evidenced by the Right Certificate or Right
Certificates surrendered shall have entitled such holder to purchase. If this
Right Certificate shall be exercised in part, the holder shall be entitled to
receive upon surrender hereof another Right Certificate or Right Certificates
for the number of whole Rights not exercised.

Subject to the provisions of the Rights Agreement, the Rights evidenced by
this Certificate (i) may be redeemed by the Company at a redemption price of
$.001 per Right or (ii) may be exchanged in whole or in part for shares of the
Company's Common Stock, par value $.001 per share, or Preferred Stock or other
property as set forth in the Rights Agreement.

No fractional Preferred Shares will be issued upon the exercise of any
Right or Rights evidenced hereby (other than fractions which are integral
multiples of one one-hundredth of a Preferred Share, which may, at the election
of the Company, be evidenced by depositary receipts) but in lieu thereof a cash
payment will be made, as provided in the Rights Agreement.

B-2

No holder of this Right Certificate shall be entitled to vote or receive
dividends or be deemed for any purpose the holder of the Preferred Shares or of
any other securities of the Company which may at any time be issuable on the
exercise hereof, nor shall anything contained in the Rights Agreement or herein
be construed to confer upon the holder hereof, as such, any of the rights of a
stockholder of the Company or any right to vote for the election of directors or
upon any matter submitted to stockholders at any meeting thereof, or to give or
withhold consent to any corporate action, or to receive notice of meetings or
other actions affecting stockholders (except as provided in the Rights
Agreement), or to receive dividends or subscription rights, or otherwise, until
the Right or Rights evidenced by this Right Certificate shall have been
exercised as provided in the Rights Agreement.

This Right Certificate shall not be valid or obligatory for any purpose
until it shall have been countersigned by the Rights Agent.

WITNESS the facsimile signature of the proper officers of the Company and
its corporate seal. Dated as of __________.

ATTEST: CORVAS INTERNATIONAL, INC.

----------------------------------- ----------------------------------------
▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇
Secretary President and Chief Executive Officer

COUNTERSIGNED:

AMERICAN STOCK TRANSFER AND TRUST COMPANY
as Rights Agent

By:
--------------------------------
Authorized Signature

B-3

Form of Reverse Side of Right Certificate

FORM OF ASSIGNMENT

(To be executed by the registered holder if such
holder desires to transfer the Right Certificate.)

FOR VALUE RECEIVED ______________________________________ hereby sells,
assigns and transfers unto

--------------------------------------------------------------------
(Please print name and address of transferee)

______________________________________________________________ this Right
Certificate, together with all right, title and interest therein, and does
hereby irrevocably constitute and appoint ________________________ Attorney, to
transfer the within Right Certificate on the books of the within-named Company,
with full power of substitution.

Dated:
--------------------

------------------------------
Signature

Form of Reverse Side of Right Certificate -- continued

B-4

Signature Guaranteed:

Signatures must be guaranteed by an "eligible guarantor institution" as
defined in Rule 17Ad-15 promulgated under the Securities Exchange Act of 1934,
as amended.

---------------------------------------------------------------

The undersigned hereby certifies that (1) the Rights evidenced by this
Right Certificate are not being sold, assigned or transferred by or on behalf of
a Person who is or was an Acquiring Person, an Interested Stockholder or an
Affiliate or Associate thereof (as such terms are defined in the Rights
Agreement); and (2) after due inquiry and to the best of the knowledge of the
undersigned, the undersigned did not acquire the Rights evidenced by this Right
Certificate from any Person who is or was an Acquiring Person, an Interested
Stockholder, or an Affiliate or Associate thereof.

------------------------------
Signature

B-5

FORM OF ELECTION TO PURCHASE

(To be executed if holder desires to exercise
Rights represented by the Right Certificate.)

TO AMERICAN STOCK TRANSFER AND TRUST COMPANY:

The undersigned hereby irrevocably elects to exercise
___________________________ Rights represented by this Right Certificate to
purchase the Preferred Shares issuable upon the exercise of such Rights and
requests that certificates for such Preferred Shares be issued in the name of:

Please insert social security
or other identifying number: ______________

--------------------------------------------------------------
(Please print name and address)

--------------------------------------------------------------

If such number of Rights shall not be all the Rights evidenced by this Right
Certificate, a new Right Certificate for the balance remaining of such Rights
shall be registered in the name of and delivered to:

Please insert social security
or other identifying number: ______________

--------------------------------------------------------------
(Please print name and address)

--------------------------------------------------------------

Dated: _________________

------------------------------
Signature

Form of Reverse Side of Right Certificate -- continued

B-6

Signature Guaranteed:

Signatures must be guaranteed by an "eligible guarantor institution" as
defined in Rule 17Ad-15 promulgated under the Securities Exchange Act of 1934,
as amended.

---------------------------------------------------------------

The undersigned hereby certifies that (1) the Rights evidenced by this
Right Certificate are not beneficially owned by nor are they being exercised on
behalf of an Acquiring Person, an Interested Stockholder or an Affiliate or
Associate thereof (as such terms are defined in the Rights Agreement); and
(2) after due inquiry and to the best of the knowledge of the undersigned, the
undersigned did not acquire the Rights evidenced by this Right Certificate from
any Person who is or was an Acquiring Person, an Interested Stockholder, or an
Affiliate or Associate thereof.

------------------------------
Signature

---------------------------------------------------------------

NOTICE

The signature in the Form of Assignment or Form of Election to Purchase, as
the case may be, must conform to the name as written upon the face of this Right
Certificate in every particular, without alteration or enlargement or any change
whatsoever.

In the event the certification set forth above in the Form of Assignment or
the Form of Election to Purchase, as the case may be, is not completed, the
Company and the Rights Agent will deem the beneficial owner of the Rights
evidenced by this Right Certificate to be an Acquiring Person or an Affiliate or
Associate thereof (as defined in the Rights Agreement) and such Assignment or
Election to Purchase will not be honored.

B-7

EXHIBIT C

SUMMARY OF RIGHTS TO PURCHASE
PREFERRED SHARES

On September 18, 1997, the Board of Directors of CORVAS INTERNATIONAL, INC.
(the "Company") declared a dividend of one preferred share purchase right (a
"Right") for each outstanding share of common stock, par value $.001 per share
(the "Common Shares"), of the Company. The dividend is effective as of
October 15, 1997 (the "Record Date") with respect to the stockholders of record
on that date. The Rights will also attach to new Common Shares issued after
the Record Date. Each Right entitles the registered holder to purchase from the
Company one 1/100 of a share of Series C Junior Participating Preferred Stock,
par value $.001 per share (the "Preferred Shares"), of the Company at a price of
$50.00 per one 1/100 of a Preferred Share (the "Purchase Price"), subject to
certain anti-dilution adjustments. Each Preferred Share is designed to be the
economic equivalent of 100 Common Shares. The description and terms of the
Rights are set forth in a Rights Agreement dated as of September 18, 1997 (the
"Rights Agreement"), between the Company and American Stock Transfer and Trust
Company (the "Rights Agent").

DETACHMENT AND TRANSFER OF RIGHTS

Initially, the Rights will be evidenced by the stock certificates
representing Common Shares then outstanding, and no separate Right Certificates
will be distributed. Until the earlier to occur of (i) a public announcement
that a person or group of affiliated or associated persons has acquired
beneficial ownership of 20% or more of the outstanding Common Shares (an
"Acquiring Person" as such term is defined in the Rights Agreement) or (ii) 10
business days (or such later date as the Board may determine) following the
commencement of, or announcement of an intention to make, a tender offer or
exchange offer which would result in the beneficial ownership by such person or
group of 20% or more of the outstanding Common Shares (the "Distribution Date"),
the Rights will be evidenced, with respect to any Common Share certificate
outstanding as of the Record Date, by such Common Share certificate.

The Rights Agreement provides that, until the Distribution Date (or earlier
redemption or expiration of the Rights), the Rights will be transferable with
and only with the Common Shares. Until the Distribution Date (or earlier
redemption or expiration of the Rights), new Common Share certificates issued
after the Record Date upon transfer or new issuance of Common Shares will
contain a notation incorporating the Rights Agreement by reference. Until the
Distribution Date (or earlier redemption or expiration of the Rights) the
surrender or transfer of any certificates for Common Shares outstanding

C-1.

as of the Record Date, even without such notation or a copy of this Summary of
Rights being attached thereto, will also constitute the transfer of the Rights
associated with the Common Shares represented by such certificate. As soon as
practicable following the Distribution Date, separate certificates evidencing
the Rights (the "Right Certificates") will be mailed to holders of record of the
Common Shares as of the close of business on the Distribution Date and such
separate Right Certificates alone will evidence the Rights.

EXERCISABILITY OF RIGHTS

The Rights are not exercisable until the Distribution Date. The Rights
will expire on September 18, 2007 (the "Final Expiration Date"), unless the
Final Expiration Date is extended or unless the Rights are earlier redeemed or
exchanged by the Company, in each case as described below. Until a Right is
exercised, the holder thereof, as such, will have no rights as a stockholder of
the Company, including, without limitation, the right to vote or to receive
dividends.

The Purchase Price payable, and the number of Preferred Shares or other
securities or property issuable or payable, upon exercise of the Rights are
subject to adjustment from time to time to prevent dilution. The number of
outstanding Rights and the number of one 1/100s of a Preferred Share issuable
upon exercise of each Right are also subject to adjustment in the event of a
stock split of the Common Shares, a stock dividend on the Common Shares payable
in Common Shares, or any subdivision, consolidation or combination of the Common
Shares occurring, in any such case, prior to the Distribution Date. With
certain exceptions, no adjustment in the Purchase Price will be required until
cumulative adjustments require an adjustment of at least 1% in such Purchase
Price. No fractional Preferred Shares will be issued (other than fractions
which are integral multiples of one 1/100 of a Preferred Share, which may, at
the election of the Company, be evidenced by depositary receipts) and in lieu
thereof, a payment in cash will be made based on the market price of the
Preferred Shares on the last trading day prior to the date of exercise.

TERMS OF PREFERRED SHARES

Preferred Shares purchasable upon exercise of the Rights will not be
redeemable. Each Preferred Share will be entitled to receive a quarterly
preferential dividend of $l per share, but will be entitled to receive, in the
aggregate, a dividend of 100 times the dividend declared on each Common Share.
In the event of liquidation, the holders of the Preferred Shares will be
entitled to receive a minimum preferential liquidation payment of $100 per
share, but will be entitled to receive, in the aggregate, a liquidation payment
equal to 100 times the payment made per Common Share. In the event of any
merger, consolidation or other transaction in which Common Shares are exchanged
for or changed into other stock or securities, cash and/or other property, each
Preferred Share will be

C-2.

entitled to receive 100 times the amount received per Common Share. These
rights are protected by customary anti-dilution provisions. Finally, each
Preferred Share will have 100 votes, voting together with the Common Shares.
Because of the nature of the Preferred Shares' dividend, liquidation and voting
rights, the value of the one 1/100 interest in a Preferred Share purchasable
upon exercise of each Right will approximate the value of one Common Share. The
Preferred Shares would rank junior to any other series of the Company's
preferred stock, including, without limitation, the Company's Series A and
Series B Preferred Stock.

TRIGGER OF FLIP-IN AND FLIP-OVER RIGHTS

In the event that any person or group of affiliated or associated persons
becomes an Acquiring Person, proper provision shall be made so that each holder
of a Right, other than Rights beneficially owned by the Acquiring Person or any
affiliate or associate thereof (which will thereafter be void), will thereafter
have the right to receive upon exercise that number of Common Shares having a
market value of two times the exercise price of the Right. This right will
commence on the date of public announcement that a person has become an
Acquiring Person (or the effective date of a registration statement relating to
distribution of the rights, if later) and terminate 60 days later (subject to
adjustment in the event exercise of the rights is enjoined).

Generally, under the Plan, an "Acquiring Person" shall not be deemed to
include (i) the Company, (ii) a subsidiary of the Company, (iii) any employee
benefit or compensation plan of the Company, or (iv) any entity holding Common
Shares for or pursuant to the terms of any such employee benefit or compensation
plan. In addition, except under limited circumstances, no person or entity
shall become an Acquiring Person either as the result of the acquisition of
(i) Common Shares by the Company which, by reducing the number of shares
outstanding, increases the proportionate number of shares beneficially owned by
such person or entity to 20% or more of the Common Shares then outstanding, or
(ii) Common Shares directly from the Company.

In the event that the Company is acquired in a merger or other business
combination transaction or 50% or more of its consolidated assets or earning
power are sold to an Acquiring Person, its affiliates or associates or certain
other persons in which such persons have an interest, proper provision will be
made so that each such holder of a Right will thereafter have the right to
receive, upon the exercise thereof at the then current exercise price of the
Right, that number of shares of common stock of the acquiring company which at
the time of such transaction will have a market value of two times the exercise
price of the Right.

C-3.

REDEMPTION AND EXCHANGE OF RIGHTS

At any time prior to the earlier of (i) the close of business on the day of
the first public announcement that a person has become an Acquiring Person, or
(ii) the Final Expiration Date, the Board of Directors of the Company may redeem
the Rights in whole, but not in part, at a price of $.001 per Right (the
"Redemption Price"). Under certain circumstances, the Board of Director's right
to redeem may be suspended for 180 days. In general, the redemption of the
Rights may be made effective at such time on such basis with such conditions as
the Board of Directors in its sole discretion may establish. Immediately upon
any redemption of the Rights, the right to exercise the Rights will terminate
and the only right of the holders of Rights will be to receive the Redemption
Price.

At any time after any person becomes an Acquiring Person and prior to the
acquisition by such person or group of 50% or more of the outstanding Common
Shares, the Board of Directors of the Company may exchange the Rights (other
than Rights owned by such person or group which will have become void), in whole
or in part, at an exchange ratio of one Common Share for each Right (or, if the
number of shares is not and cannot be authorized, the Company may issue
Preferred Shares, preferred stock, cash, debt or equity securities, property or
a combination thereof in exchange for the rights), subject to adjustment.

AMENDMENT OF RIGHTS

The terms of the Rights generally may be amended by the Board of Directors
of the Company without the consent of the holders of the Rights, except that
from and after such time as the Rights are distributed no such amendment may
adversely affect the interests of the holders of the Rights (excluding the
interest of any Acquiring Person).

ADDITIONAL INFORMATION

A copy of the Rights Agreement has been filed with the Securities and Exchange
Commission as an exhibit to a Current Report on Form 8-K dated October 8, 1997.
A copy of the Rights Agreement is available from the Company by writing to:
Investor Relations, Corvas International, Inc., ▇▇▇▇ ▇▇▇▇▇▇▇ ▇▇▇▇ ▇▇▇▇, ▇▇▇
▇▇▇▇▇, ▇▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇. This summary description of the Rights is not intended
to be complete and is qualified in its entirety by reference to the Rights
Agreement, which is hereby incorporated herein by reference.

C-4.

AS RIGHTS AGENT RIGHTS AGREEMENT

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