[GRAPHIC OMITTED]

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549


FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): October 13, 2006

LIGAND PHARMACEUTICALS INCORPORATED
(Exact name of registrant as specified in its charter)

DELAWARE
(State or other jurisdiction of incorporation)

000-20720
(Commission File Number)

10275 Science Center Drive,
San Diego, California
(Address of principal executive offices)

(858) 550-7500
(Registrant's telephone number, including area code)

77-0160744
(I.R.S. Employer Identification No.)

92121-1117
(Zip Code)

[GRAPHIC OMITTED]

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

|_| Written communications pursuant to Rule 425 under the Securities Act


(17 CFR 230.425)

|_| Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

|_| Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

|_| Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

[GRAPHIC OMITTED]


Item 1.01. Entry into a Material Definitive Agreement.

In connection with the expiration of the Amended and Restated Preferred Shares Rights Agreement dated September 13, 1996, as amended, between Ligand Pharmaceuticals Incorporated (the "Company") and Mellon Investor Services LLC ("Mellon"), as Rights Agent, which associated rights (as defined therein) expired on September 13, 2006, the Board of Directors of the Company approved a new 2006 Preferred Shares Rights Agreement (the "2006 Rights Agreement") with Mellon as Rights Agent. As of October 13, 2006, the Board of Directors of the Company declared a dividend of one right (a "Right" or "Rights") to purchase one one-thousandth share of the Company's Series A Participating Preferred Stock ("Series A Preferred") for each outstanding share of Common Stock, par value $0.001 per share ("Common Shares"), of the Company. The dividend is payable on October 31, 2006 (the "Record Date") to stockholders of record as of the close of business on that date. Each Right entitles the registered holder to purchase from the Company one one-thousandth of a share of Series A Preferred at an exercise price of $100 (the "Purchase Price"), subject to adjustment as described below. The description and terms of the Rights are set forth in the 2006 Rights Agreement.

Initially, the Rights will be attached to all certificates representing shares of Common Shares then outstanding, and no separate certificates evidencing the Rights ("Rights Certificates") will be distributed. Common Share certificates issued after the Record Date but prior to the Distribution Date (as defined below) will contain a notation incorporating the 2006 Rights Agreement by reference. The Rights will separate from the Common Shares, Rights Certificates will be issued and the Rights will become exercisable upon the earlier of: (i) 10 days (or such later date as may be determined by the Company's Board of Directors) following a public announcement that a person or group of affiliated or associated persons (an "Acquiring Person") has acquired, or obtained the right to acquire, beneficial ownership of 20% or more of the outstanding Common Shares, or (ii) 10 days (or such later date as may be determined by the Company's Board of Directors) following the commencement of, or announcement of an intention to make, a tender offer or exchange offer the consummation of which would result in the beneficial ownership by a person or group of 20% or more of the outstanding Common Shares. The earlier of such dates is referred to as the "Distribution Date."

Until the Distribution Date (or earlier redemption, exchange or expiration of the Rights), the surrender or transfer of any certificates for Common Shares, even without notation or a copy of the Summary of Rights being attached thereto (but as to certificates representing Common Shares issued after the Record Date, only if they bear the legend required by the 2006 Rights Agreement), 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 Rights 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 Rights Certificates alone will evidence the Rights from and after the Distribution Date.

The holders of the Rights are not required to take any action until the Rights become exercisable. As described above, the Rights are not exercisable until the Distribution Date. Holders of the Rights will be notified that the Rights have become exercisable when the Rights Agent mails the Rights Certificates. The Rights will expire on October 13, 2016 (the "Final Expiration Date"), unless earlier redeemed, exchanged or terminated under the terms of the 2006 Rights Agreement.

The Purchase Price payable, the number of Rights and the number of Series A Preferred or Common Shares or other securities or property issuable upon exercise of the Rights are subject to adjustment from time to time in the event the Company declares a dividend payable in Common Shares, subdivides the number of outstanding Common Shares into a larger number of such shares or combines the number of outstanding Common Shares into a smaller number of such shares, among other circumstances, as set forth in the 2006 Rights Agreement. With certain exceptions, no adjustment in the Purchase Price will be required unless such adjustment would require an increase or decrease of at least 1% in the Purchase Price.

Because of the nature of the dividend, liquidation and voting rights, the value of the one one-thousandth interest in a share of Series A Preferred purchasable upon exercise of each Right should approximate the value of one Common Share. Series A Preferred purchasable upon exercise of the Rights will not be redeemable. Each share of Series A Preferred will be entitled to an aggregate dividend of 1,000 times the dividend declared per Common Share. In the event of liquidation, the holders of the Series A Preferred will be entitled to a minimum preferential


liquidation payment equal to $1,000 per share. Each share of Series A Preferred will have 1,000 votes, voting together with the Common Shares. In the event of any merger, consolidation or other transaction in which the Common Shares are changed or exchanged, each share of Series A Preferred will be entitled to receive 1,000 times the amount received per Common Share. These rights are protected by customary anti-dilution provisions.

In the event that, at any time following the date on which there has been public disclosure that a person or group has become an Acquiring Person (the "Shares Acquisition Date"), (i) the Company is acquired in a merger or other business combination transaction, or (ii) 50% or more of the Company's consolidated assets or earning power are sold (other than in transactions in the ordinary course of business) (either of which event is referred to herein as an "Acquisition"), proper provision shall be made so that each holder of a Right which has not theretofore been exercised (other than Rights beneficially owned by the Acquiring Person, which will thereafter be void) will thereafter have the right to receive, upon exercise, shares of Common Stock of the acquiring company having a value equal to two times the Purchase Price.

At any time after the acquisition by an Acquiring Person of 20% or more of the Company's outstanding Common Shares and prior to the acquisition by such Acquiring Person of 50% or more of the Company's outstanding Common Shares, the Board of Directors of the Company may exchange the Rights (other than Rights owned by the Acquiring Person), in whole or in part, at an exchange ratio of one Common Share per Right, subject to adjustment.

At any time on or prior to the close of business on the earlier of
(i) the 10th day following the Shares Acquisition Date or such later date as may be determined by the Company's Board of Directors and publicly announced by the Company, or (ii) the Final Expiration Date of the Rights, the Company may redeem the Rights in whole, but not in part, at a price of $0.01 per Right (the "Redemption Price"). The redemption of the Rights may be made effective at such time, on such basis and 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.

Until a Right is exercised, the holder thereof, as such, will have no rights as a stockholder of the Company (other than any rights resulting from such holder's ownership of Common Shares), including, without limitation, the right to vote or to receive dividends.

The provisions of the 2006 Rights Agreement may be supplemented or amended by the Board of Directors in any manner prior to the close of business on the Distribution Date without the approval of the Rights holders. After the Distribution Date, the provisions of the 2006 Rights Agreement may be amended by the Board in order to cure any ambiguity, defect or inconsistency, to make changes which do not adversely affect the interests of holders of Rights (excluding the interests of any Acquiring Person), or to shorten or lengthen any time period under the 2006 Rights Agreement; provided, however, that no amendment to adjust the time period governing redemption shall be made at such time as the Rights are not redeemable.

A copy of the 2006 Rights Agreement, which includes as Exhibit A the form of Rights Certificate, is attached as Exhibit 4.1 to this Current Report on Form 8-K and incorporated herein by reference. This summary description of the Rights does not purport to be complete and is qualified in its entirety by reference to the 2006 Rights Agreement.

Item 2.03. Creation of a Direct Financial Obligation

On October 12, 2006, in connection with the pending sale of its Avinza(R)-related assets (the "Asset Sale"), Ligand obtained a loan from and became obligated to King Pharmaceuticals, Inc. in the amount of $37.75 million plus interest (the "Loan"). Additional details regarding the Asset Sale may be found in Ligand's Current Report on Form 8-K, filed on September 11, 2006.

The terms of the Loan include a 9.5 % interest rate and a security interest in the Avinza(R) assets plus a portion of the proceeds from Ligand's pending sale of its oncology assets, up to the amount of the Loan, including interest. The principal amount of the Loan was used to make a payment in that amount due from Ligand to Organon USA Inc. under the Termination and Return of Rights Agreement between Ligand and Organon dated January 1, 2006. King


agreed as part of the Asset Sale to assume this liability to Organon. Thus upon closing of the Asset Sale, the amount of the closing payment due from King to Ligand will be increased by the amount of the Loan, including interest, and an equal amount will be credited against that payment for repayment of the Loan. In the event the Asset Sale does not close before January 8, 2007, the Loan, including accrued interest, would become due and payable.

Item 3.03. Material Modification to Rights of Security Holders.

The information required by this item is included in Item 1.01.

Item 9.01. Financial Statements and Exhibits.

(d)      Exhibits

EXHIBIT NUMBER     DESCRIPTION
---------------    ------------
4.1                2006 Preferred Shares Rights Agreement, by and between
                   Ligand Pharmaceuticals Incorporated and Mellon Investor
                   Services LLC, dated as of October 13, 2006.

99.1               Press release dated October 16, 2006 announcing the
                   adoption of the 2006 Preferred Shares Rights Agreement.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

LIGAND PHARMACEUTICALS INCORPORATED

Date : October 17, 2006         By:     /s/ Warner R. Broaddus
                                Name:   Warner R. Broaddus
                                Title:  Vice President, General Counsel &
                                        Secretary


EXHIBIT INDEX

EXHIBIT NUMBER     DESCRIPTION
---------------    ------------

4.1                2006 Preferred Shares Rights Agreement, by and between
                   Ligand Pharmaceuticals Incorporated and Mellon Investor
                   Services LLC, dated as of October 13, 2006.

99.1               Press release dated October 16, 2006 announcing the
                   adoption of the 2006 Preferred Shares Rights Agreement.


Exhibit 4.1

LIGAND PHARMACEUTICALS INCORPORATED

AND

MELLON INVESTOR SERVICES LLC

RIGHTS AGENT

2006 PREFERRED SHARES RIGHTS AGREEMENT

DATED AS OF OCTOBER 13, 2006


                                TABLE OF CONTENTS

                                                                            PAGE

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


SECTION 2. APPOINTMENT OF RIGHTS AGENT.........................................5


SECTION 3. ISSUANCE OF RIGHTS CERTIFICATES.....................................5


SECTION 4. FORM OF RIGHTS CERTIFICATES.........................................7


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


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

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


SECTION 8. CANCELLATION AND DESTRUCTION OF RIGHTS CERTIFICATES................10


SECTION 9. RESERVATION AND 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..................................................20


SECTION 14. FRACTIONAL RIGHTS AND FRACTIONAL SHARES...........................22

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SECTION 15. RIGHTS OF ACTION..................................................23


SECTION 16. AGREEMENT OF RIGHTS HOLDERS.......................................23


SECTION 17. RIGHTS CERTIFICATE HOLDER NOT DEEMED A STOCKHOLDER................24


SECTION 18. CONCERNING THE RIGHTS AGENT.......................................24

SECTION 19. MERGER OR CONSOLIDATION OR CHANGE OF NAME OF RIGHTS AGENT.........24


SECTION 20. DUTIES OF RIGHTS AGENT............................................25


SECTION 21. CHANGE OF RIGHTS AGENT............................................27


SECTION 22. ISSUANCE OF NEW RIGHTS CERTIFICATES...............................28


SECTION 23. REDEMPTION........................................................28


SECTION 24. EXCHANGE..........................................................29


SECTION 25. NOTICE OF CERTAIN EVENTS..........................................31


SECTION 26. NOTICES...........................................................31


SECTION 27. SUPPLEMENTS AND AMENDMENTS........................................31


SECTION 28. SUCCESSORS........................................................32


SECTION 29. DETERMINATIONS AND ACTIONS BY THE BOARD OF DIRECTORS, ETC.........32


SECTION 30. BENEFITS OF THIS AGREEMENT........................................32


SECTION 31. SEVERABILITY......................................................32

                                       ii

SECTION 32. GOVERNING LAW.....................................................33


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


SECTION 34. DESCRIPTIVE HEADINGS..............................................33




EXHIBITS

Exhibit A.........Form of Rights Certificate

Exhibit B.........Summary of Rights

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2006 PREFERRED SHARES RIGHTS AGREEMENT

This 2006 Preferred Shares Rights Agreement (this "Agreement"), is dated as of October 13, 2006, between Ligand Pharmaceuticals Incorporated, a Delaware corporation (the "Company"), and MELLON INVESTOR SERVICES LLC (the "Rights Agent").

WHEREAS, on October 13, 2006 (the "Rights Dividend Declaration Date"), the Board of Directors of the Company authorized and declared a dividend of one Preferred Share purchase right (a "Right") for each Common Share (as hereinafter defined) of the Company outstanding as of the Close of Business (as hereinafter defined) on October 31, 2006 (the "Record Date"), each Right representing the right to purchase one one-thousandth of a share of Series A Participating Preferred Stock (as such number may be adjusted pursuant to the provisions of this Agreement), having the rights, preferences and privileges set forth in the Certificate of Designation of Rights, Preferences and Privileges of Series A Participating Preferred Stock by the Company with the Secretary of State of the State of Delaware, upon the terms and subject to the conditions herein set forth, and further authorized and directed the issuance of one Right (as such number may be adjusted pursuant to the provisions of this Agreement) with respect to each Common Share that shall become outstanding between the Record Date and the earlier of the Distribution Date and the Expiration Date (as such terms are hereinafter defined), and in certain circumstances after the Distribution Date.

NOW, THEREFORE, in consideration of the promises 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 who or which, together with all Affiliates and Associates of such Person, shall be the Beneficial Owner of 20% or more of the Common Shares then outstanding, but shall not include 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. Notwithstanding the foregoing, no Person shall be deemed to be an Acquiring Person either (i) 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 of the Company then outstanding; PROVIDED, HOWEVER, that if a Person shall become the Beneficial Owner of 20% or more of the Common Shares of the Company then outstanding by reason of share purchases by the Company and shall, after such share purchases by the Company, become the Beneficial Owner of any additional Common Shares of the Company, then such Person shall be deemed to be an Acquiring Person. Notwithstanding the foregoing, if the Board of Directors of the Company determines in good faith that a Person who would otherwise be an "Acquiring Person", as defined pursuant to this paragraph (a), has become such inadvertently, and such Person divests as promptly as practicable a sufficient number of Common Shares so that such Person would no longer be an "Acquiring Person", as defined pursuant to this paragraph (a), then such Person shall not be deemed to be an "Acquiring Person" for any purposes of this Agreement. Notwithstanding anything in this Agreement to the contrary, neither the Third Point Entities nor any Affiliates or Associates of

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Third Point Entities,including, without limitation, the Third Point Designees, shall be deemed to be an Acquiring Person by virtue of the beneficial ownership by Third Point Entities or such Affiliates or Associates on or after December 8, 2005 of outstanding Common Shares acquired solely as a result of the Third Point Designees' service as members of the Company's Board of Directors, including without limitation the Initial Option Grants.

(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.

(c) A Person shall be deemed the "Beneficial Owner" of and shall be deemed to "beneficially own" any securities:

(i) which such Person or any of such Person's Affiliates or Associates beneficially owns, directly or indirectly, for purposes of Section 13(d) of the Exchange Act and Rule 13d-3 thereunder (or any comparable or successor law or regulation);

(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 the Rights), warrants or options, or otherwise; PROVIDED, HOWEVER, that a Person shall not be deemed pursuant to this Section 1(c)(ii)(A) the Beneficial Owner of, or to beneficially own, (1) 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 (2) securities which a Person or any of such Person's Affiliates or Associates may be deemed to have the right to acquire pursuant to any merger or other acquisition agreement between the Company and such Person (or one or more of its Affiliates or Associates) if such agreement has been approved by the Board of Directors of the Company prior to there being an Acquiring Person; 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 under this
Section 1(c)(ii)(B) 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 of 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 (or any Affiliate or Associate thereof) with which such Person or any of such Person's Affiliates or Associates has any agreement, arrangement or understanding, whether or not in writing (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)) or disposing of any securities of the Company; PROVIDED, HOWEVER, that in no case shall an officer or director of the Company be deemed (x) the Beneficial Owner of any securities

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beneficially owned by another officer or director of the Company solely by reason of actions undertaken by such persons in their capacity as officers or directors of the Company or (y) the Beneficial Owner of securities held of record by the trustee of any employee benefit plan of the Company or any Subsidiary of the Company for the benefit of any employee of the Company or any Subsidiary of the Company, other than the officer or director, by reason of any influence that such officer or director may have over the voting of the securities held in the plan.

(d) "Business Day" shall mean any day other than a Saturday, Sunday or a day on which banking institutions in California, New York or New Jersey 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., New York time, on such date; PROVIDED, however, that if such date is not a Business Day it shall mean 5:00 P.M., New York time, on the next succeeding Business Day.

(f) "Common Shares" when used with reference to the Company shall mean the shares of Common Stock of the Company, par value $0.001 per share. "Common Shares" when used with 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 mean the earlier of (i) the Close of Business on the tenth day (or such later date as may be determined by action of the Company's Board of Directors after the Shares Acquisition Date (or, if the tenth day after the Shares Acquisition Date occurs before the Record Date, the Close of Business on the Record Date) or (ii) the Close of Business on the tenth day (or such later date as may be determined by action of the Company's Board of Directors after the date that a tender or exchange offer 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 Person or entity organized, appointed or established by the Company for or pursuant to the terms of any such plan) is first published or sent or given within the meaning of Rule 14d-2(a) of the General Rules and Regulations under the Exchange Act, if, assuming the successful consummation thereof, such Person would be the Beneficial Owner of 20% or more of the shares of Common Stock then outstanding. Notwithstanding anything in this Agreement to the contrary, a Distribution Date shall not be deemed to have occurred by virtue of the beneficial ownership by Third Point Entities on or after December 8, 2005 of outstanding Common Shares acquired solely as a result of the Third Point Designees' service as members of the Company's Board of Directors, including without limitation the Initial Option Grants.

(h) "Equivalent Shares" shall mean Preferred Shares and any other class or series of capital stock of the Company which is entitled to participate in dividends and other distributions, including distributions upon the liquidation, dissolution or winding up of the Company, on a proportional basis with the Common Shares. In calculating the number of any class or series of Equivalent Shares for purposes of Section 11 of this Agreement, the number of shares, or fractions of a share, of such class or series of capital stock that is entitled to the same dividend or distribution as a whole Common Share shall be deemed to be one share.

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(i) "Expiration Date" shall mean the earliest of (i) the Close of Business on the Final Expiration Date, (ii) the Redemption Date, (iii) the time at which the Board of Directors orders the exchange of the Rights as provided in Section 24 hereof, or (iv) the consummation of a transaction contemplated by Section 13(d) hereof.

(j) "Final Expiration Date" shall mean October 13, 2016.

(k) "Initial Option Grant" shall mean that certain option to purchase 20,000 Common Shares pursuant to the Company's 2002 Stock Incentive Plan, granted to each Third Point Designee upon his or her election as a non-employee member of the Board of Directors of the Company.

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

(m) "Preferred Shares" shall mean shares of Series A Participating Preferred Stock of the Company.

(n) "Purchase Price" shall have the meaning set forth in Section 4(a)

(o) "Record Date" shall have the meaning set forth in the recitals at the beginning of this Agreement.

(p) "Redemption Date" shall mean the time at which the Board of Directors of the Company orders redemption of the Rights as provided in Section 23 hereof.

(q) "Redemption Price" shall have the meaning set forth in Section 23(a) hereof.

(r) "Rights Dividend Declaration Date" shall have the meaning set forth in the recitals at the beginning of this Agreement.

(s) "Section 13 Event" shall mean any event described in clause (i), (ii) or (iii) of Section 13(a) hereof.

(t) "Shares Acquisition Date" shall mean the first date of public announcement (which, for purposes of this definition, shall include, without limitation, a report filed pursuant to Section 13(d) under the Exchange Act) by the Company or an Acquiring Person that an Acquiring Person has become such; PROVIDED that, if such person is determined not to have become an Acquiring Person pursuant to
Section 1(a)(ii) hereof, then no Shares Acquisition Date shall be deemed to have occurred.

(u) "Subsidiary" of any Person shall mean any corporation or other entity of which an amount of voting securities sufficient to elect a majority of the directors or Persons having similar authority of such corporation or other entity is beneficially owned, directly or indirectly, by such Person, or any corporation or other entity otherwise controlled by such Person.

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(v) "Third Point Designee" shall mean each of Daniel S. Loeb, Jeffrey R. Perry, and Brigette Roberts, M.D.

(w) "Third Point Entities" shall mean Third Point LLC, a Delaware limited liability company, Third Point Offshore Fund, Ltd., a Cayman Islands limited liability exempted company, Third Point Partners LP, a Delaware limited partnership, Third Point Ultra Ltd., a British Virgin Islands limited liability company, Lyxor/Third Point Fund Ltd., a Jersey public company with limited liability, and Third Point Partners Qualified LP, a Delaware limited partnership.

(x) "Total Exercise Price" shall have the meaning set forth in Section 4(a) hereof.

(y) "Trading Day" shall have the meaning set forth in Section 11(d) hereof.

(z) A "Triggering Event" shall be deemed to have occurred upon any Person (other than the Company, any Subsidiary of the Company, any employee benefit plan of the Company or any Subsidiary of the Company, 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, becoming an Acquiring Person.

SECTION 2. .......APPOINTMENT OF RIGHTS AGENT. The Company hereby appoints the Rights Agent to act as agent for the Company 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. The Rights Agent shall have no duty to supervise, and in no event shall be liable for, the acts of omissions of any such co-Rights Agent.

SECTION 3. .......ISSUANCE OF RIGHTS CERTIFICATES.

(a) Until the Distribution Date, (i) the Rights will be evidenced (subject to the provisions of Sections 3(b) and 3(c) hereof) by the certificates for Common Shares registered in the names of the holders thereof (which certificates shall also be deemed to be Rights Certificates) and not by separate Rights Certificates and (ii) the right to receive Rights Certificates will be transferable only in connection with the transfer of Common Shares. Until the earlier of the Distribution Date or the Expiration Date, the surrender for transfer of such certificates for Common Shares shall also constitute the surrender for transfer of the Rights associated with the Common Shares represented thereby. 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 and provided with the necessary information, send) by first-class, 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 Rights Certificate, in substantially the form of EXHIBIT A hereto (a "Rights Certificate"), evidencing one Right for each Common Share so held, subject to adjustment as provided herein. In the event that an adjustment in the number of Rights per Common Share has been made pursuant to
Section 11(a)(i), Section 11(i) or Section 11(p) hereof, then at the time of distribution of the Rights Certificates, the Company shall make

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the necessary and appropriate rounding adjustments (in accordance with
Section 14(a) hereof) so that Rights Certificates representing only whole numbers of Rights are distributed and cash is paid in lieu of any fractional Rights. As of the Distribution Date, the Rights will be evidenced solely by such Rights Certificates and may be transferred by the transfer of the Rights Certificates as permitted hereby, separately and apart from any transfer of one or more Common Shares, and the holders of such Rights Certificates as listed in the records of the Company or any transfer agent or registrar for the Rights shall be the record holders thereof. The Company shall promptly notify the Rights Agent in writing upon the occurrence of the Distribution Date. Until such notice is received by the Rights Agent, the Rights Agent may presume conclusively for all purposes that the Distribution Date has not occurred.

(b) On the Record Date or as soon as practicable thereafter, the Company will send a copy of a Summary of Rights in substantially the form of EXHIBIT B 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.

(c) Unless the Board of Directors by resolution adopted at or before the time of the issuance (including pursuant to the exercise of rights under the Company's benefit plans) of any Common Shares specifies to the contrary, Rights shall be issued in respect of all Common Shares that are issued after the Record Date but prior to the earlier of the Distribution Date or the Expiration Date or, in certain circumstances provided in Section 22 hereof, after the Distribution Date. Certificates representing such Common Shares shall also be deemed to be certificates for Rights, and shall bear the following legend:

This certificate also evidences and entitles the holder hereof to certain rights as set forth in the 2006 Preferred Shares Rights Agreement between LIGAND PHARMACEUTICALS INCORPORATED and MELLON INVESTOR SERVICES LLC as the Rights Agent, dated as of October 13, 2006, 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 Ligand Pharmaceuticals Incorporated. 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. Ligand Pharmaceuticals Incorporated will mail to the holder of this certificate a copy of the Rights Agreement without charge after receipt of a written request therefor. Under certain circumstances set forth in the Rights Agreement, Rights issued to, or held by, any Person who is, was or becomes an Acquiring Person or any Affiliate or Associate thereof (as such terms are defined in the Rights Agreement), whether currently held by or on behalf of such Person or by any subsequent holder, may become null and void.

With respect to such certificates containing the foregoing legend, until the earlier of (i) the Distribution Date or (ii) the Expiration Date, the Rights associated with the Common Shares

6

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.

SECTION 4. .......FORM OF RIGHTS CERTIFICATES.

(a) The Rights Certificates (and the forms of election to purchase Common Shares and of assignment to be printed on the reverse thereof) shall be substantially in the form of EXHIBIT A hereto and may have such marks of identification or designation and such legends, summaries or endorsements printed thereon as the Company may deem appropriate (but which do not affect the rights, duties and responsibilities of the Rights Agent) 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 Section 11 and Section 22 hereof, the Rights Certificates, whenever distributed, shall be dated as of the Record Date (or in the case of Rights issued with respect to Common Shares issued by the Company after the Record Date, as of the date of issuance of such Common Shares) and on their face shall entitle the holders thereof to purchase such number of one-thousandths of a Preferred Share as shall be set forth therein at the price set forth therein (such exercise price per one one-thousandth of a Preferred Share being hereinafter referred to as the "Purchase Price" and the aggregate exercise price of all Preferred Shares issuable upon exercise of one Right being hereinafter referred to as the "Total Exercise Price"), but the number and type of securities purchasable upon the exercise of each Right and the Purchase Price shall be subject to adjustment as provided herein.

(b) Any Rights Certificate issued pursuant to Section 3(a) or Section 22 hereof that represents Rights beneficially owned by: (i) an Acquiring Person or any Associate or Affiliate of an Acquiring Person, (ii) a transferee of an Acquiring Person (or of any such Associate or Affiliate) who becomes a transferee after the Acquiring Person becomes such or (iii) a transferee of an Acquiring Person (or of any such Associate or Affiliate) who becomes a transferee prior to or concurrently with the Acquiring Person 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 such 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 avoidance of Section 7(e) hereof, and any Rights Certificate issued pursuant to Section 6 or Section 11 hereof upon transfer, exchange, replacement or adjustment of any other Rights Certificate referred to in this sentence, shall contain (to the extent feasible) the following legend:

The Rights represented by this Rights 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

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terms are defined in the Rights Agreement). Accordingly, this Rights Certificate and the Rights represented hereby may become null and void in the circumstances specified in Section 7(e) of the Rights Agreement.

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

(a) The Rights Certificates shall be executed on behalf of the Company by its Chairman of the Board, its Chief Executive Officer, its President or any Vice President, either manually or by facsimile signature, and by the Secretary or an Assistant Secretary of the Company, either manually or by facsimile signature, and shall have affixed thereto the Company's seal (if any) or a facsimile thereof. The Rights 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 Rights Certificates shall cease to be such officer of the Company before countersignature by the Rights Agent and issuance and delivery by the Company, such Rights 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 Rights Certificates had not ceased to be such officer of the Company; and any Rights Certificate may be signed on behalf of the Company by any person who, at the actual date of the execution of such Rights Certificate, shall be a proper officer of the Company to sign such Rights Certificate, although at the date of the execution of this Agreement any such person was not such an officer.

(b) Following the Distribution Date and the receipt by Rights Agent of a written notice to that effect, in the Rights Agent will keep or cause to be kept, at its office designated for such purposes, books for registration and transfer of the Rights Certificates issued hereunder. Such books shall show the names and addresses of the respective holders of the Rights Certificates, the number of Rights evidenced on its face by each of the Rights Certificates and the date of each of the Rights Certificates.

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

(a) Subject to the provisions of Sections 7(e), 14 and 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 Expiration Date, any Rights Certificate or Rights Certificates may be transferred, split up, combined or exchanged for another Rights Certificate or Rights Certificates, entitling the registered holder to purchase a like number of one-thousandths of a Preferred Share (or, following a Triggering Event, other securities, cash or other assets, as the case may be) as the Rights Certificate or Rights Certificates surrendered then entitled such holder to purchase. Any registered holder desiring to transfer, split up, combine or exchange any Rights Certificate or Rights Certificates shall make such request in writing delivered to the Rights Agent, and shall surrender the Rights Certificate or Rights 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 Rights Certificate until the registered holder shall have

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completed and signed the certificate contained in the form of assignment on the reverse side of such Rights 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 or the Rights Agent shall reasonably request. Thereupon the Rights Agent shall, subject to Sections 7(e), 14 and 24 hereof, countersign and deliver to the person entitled thereto a Rights Certificate or Rights 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 Rights Certificates. The Rights Agent shall have no responsibility under this section unless and until it is satisfied that all such taxes and/or governmental charges have been paid.

(b) Upon receipt by the Company and the Rights Agent of evidence reasonably satisfactory to them of the loss, theft, destruction or mutilation of a Rights 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 Rights Certificate if mutilated, the Company will make and deliver a new Rights Certificate of like tenor to the Rights Agent for delivery to the registered holder in lieu of the Rights Certificate so lost, stolen, destroyed or mutilated.

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

(a) Subject to Sections 7(e), 23(b) and 24(b) hereof, the registered holder of any Rights 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 Rights 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-thousandth of a Preferred Share as to which the Rights are exercised, at or prior to the Expiration Date.

(b) The Purchase Price for each one-thousandth of a Preferred Share issuable pursuant to the exercise of a Right shall initially be One Hundred Dollars ($100.00), 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 Rights Certificate representing exercisable Rights, with the form of election to purchase duly executed, accompanied by payment of the Purchase Price for the number of one-thousandths of a Preferred Share (or other securities or property, as the case may be) to be purchased and an amount equal to any applicable transfer tax or charge required to be paid by the holder of such Rights Certificate in accordance with Section 9 hereof in cash, or by certified check or cashier's check payable to the order of the Company, the Rights Agent shall, subject to Section 20(k) hereof, thereupon promptly (i) (A) requisition from any transfer agent of the Preferred Shares (or make available, if the Rights Agent is the transfer agent for the Preferred Shares) a certificate or certificates for the number of one-thousandths of a Preferred Share to be purchased and the Company hereby irrevocably authorizes its transfer agent to comply with all such requests or (B) if the Company shall have elected to deposit the

9

total number of one-thousandths of a Preferred Share issuable upon exercise of the Rights hereunder with a depositary agent, requisition from the depositary agent of depositary receipts representing such number of one-thousandths 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 Rights Certificate, registered in such name or names as may be designated by such holder and (iv) when appropriate, after receipt thereof, deliver such cash to or upon the order of the registered holder of such Rights Certificate. The payment of the Purchase Price (as such amount may be reduced (including to zero) pursuant to Section 11(a)(iii) hereof) may be made in cash or by certified bank check or bank draft payable to the order of the Company. In the event that the Company is obligated to issue other securities of the Company, pay cash and/or distribute other property pursuant to
Section 11(a) hereof, the Company will make all arrangements necessary so that such other securities, cash and/or other property are available for distribution by the Rights Agent, if and when appropriate.

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

(e) Notwithstanding anything in this Agreement to the contrary, from and after the first occurrence of a Triggering Event or a Section 13 Event, any Rights beneficially owned by (i) an Acquiring Person or an Associate or Affiliate of an Acquiring Person, (ii) a transferee of an Acquiring Person (or of any such Associate or Affiliate) who becomes a transferee after the Acquiring Person becomes such (a "Post Transferee"), (iii) a transferee of an Acquiring Person (or of any such Associate or Affiliate) who becomes a transferee prior to or concurrently with the Acquiring Person 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 7(e) (a "Prior Transferee") or (iv) any subsequent transferee receiving transferred Rights from a Post Transferee or a Prior Transferee, either directly or through one or more intermediate transferees, 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 7(e) and
Section 4(b) hereof are complied with, but shall have no liability to any holder of Rights Certificates or to any other Person as a result of its failure to make any determinations with respect to an Acquiring Person or any of such Acquiring Person's Affiliates, Associates or transferees hereunder.

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(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 certificate contained in 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 RIGHTS CERTIFICATES. All Rights 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 surrendered to the Rights Agent, shall be canceled by it, and no Rights 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 Rights Certificate purchased or acquired by the Company otherwise than upon the exercise thereof. The Rights Agent shall deliver all canceled Rights Certificates to the Company, or shall, at the written request of the Company, destroy such canceled Rights Certificates, and in such case shall deliver a certificate of destruction thereof to the Company.

SECTION 9. .......RESERVATION AND AVAILABILITY OF PREFERRED SHARES.

(a) The Company covenants and agrees that it will use its best efforts to cause to be reserved and kept available out of and to the extent of its authorized and unissued shares of Preferred Stock not reserved for another purpose (and, following the occurrence of a Triggering Event, out of its authorized and unissued shares of Common Stock and/or other securities), the number of Preferred Shares (and, following the occurrence of the Triggering Event, Common Stock and/or other securities) that will be sufficient to permit the exercise in full of all outstanding Rights.

(b) If the Company shall hereafter list any of its Preferred Shares on a national securities exchange, then so long as the Preferred Shares (and, following the occurrence of a Triggering Event, Common Shares and/or other securities) issuable and deliverable upon exercise of the Rights may be listed on such exchange, the Company shall use its best efforts to cause, from and after such time as the Rights become exercisable (but only to the extent that it is reasonably likely that the Rights will be exercised), all shares reserved for such issuance to be listed on such exchange upon official notice of issuance upon such exercise.

(c) The Company shall use its best efforts to (i) file, as soon as practicable following the earliest date after the first occurrence of a Triggering Event in which the consideration to be delivered by the Company upon exercise of the Rights has been determined in accordance with Section 11(a)(iii) hereof, or as soon as is required by law following the Distribution Date, as the case may be, a registration statement under the Securities Act of 1933, as amended (the "Securities Act"), with respect to the securities purchasable upon exercise of the Rights on an appropriate form, (ii) cause such registration statement to become effective as soon as practicable after such filing and (iii) cause such registration statement to remain effective

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(with a prospectus at all times meeting the requirements of the Securities Act) until the earlier of (A) the date as of which the Rights are no longer exercisable for such securities and (B) the date of expiration of the Rights. The Company may temporarily suspend, for a period not to exceed ninety (90) days after the date set forth in clause (i) of the first sentence of this Section
9(c), the exercisability of the Rights in order to prepare and file such registration statement and permit it to become effective. Upon any such suspension, the Company shall issue a public announcement stating, and notify the Rights Agent, that the exercisability of the Rights has been temporarily suspended, as well as a public announcement and notification to the Rights Agent at such time as the suspension is no longer in effect. The Company will also take such action as may be appropriate under, or to ensure compliance with, the securities or "blue sky" laws of the various states in connection with the exercisability of the Rights. Notwithstanding any provision of this Agreement to the contrary, the Rights shall not be exercisable in any jurisdiction, unless the requisite qualification in such jurisdiction shall have been obtained, or an exemption therefrom shall be available, and until a registration statement has been declared effective.

(d) The Company covenants and agrees that it will take all such action as may be necessary to ensure that all Preferred Shares 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.

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

SECTION 10. ......PREFERRED SHARES RECORD DATE. Each person in whose name any certificate for a number of one-thousandths of a Preferred Share is issued upon the exercise of Rights shall for all purposes be deemed to have become the holder of record of Preferred Shares represented thereby on, and such certificate shall be dated, the date upon which the Rights Certificate evidencing such Rights was duly surrendered and payment of the Purchase Price multiplied by the number of one-thousandths of a Preferred Share with respect to which the Rights have been exercised (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 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 transfer books of the Company are open. Prior to the exercise of the Rights evidenced thereby, the holder of a Rights Certificate 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

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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 and kind of shares or other property covered by each Right and the number of Rights outstanding are subject to adjustment from time to time as provided in this Section 11.

(a) (i) In the event the Company shall at any time after the date of this Agreement (A) declare a dividend on the Common Shares payable in Common Shares, (B) subdivide the outstanding Common Shares, (C) combine the outstanding Common Shares (by reverse stock split or otherwise) into a smaller number of Common Shares, or (D) issue any shares of its capital stock in a reclassification of the Common Shares (including any such reclassification in connection with a consolidation or merger in which the Company is the continuing or surviving corporation), then, in each such event, except as otherwise provided in this
Section 11(a) and Section 7(e) hereof: (1) each of the Rights outstanding at the time of the record date for such dividend or the effective date of such subdivision, combination or reclassification shall be proportionately adjusted to that number of Rights (calculated to the nearest one ten-thousandth (1/10,000) of a Right) equal to a fraction (the "Exchange Ratio"), the numerator of which shall be the total number of Common Shares or shares of capital stock issued in such reclassification of the Common Shares outstanding immediately following such time and the denominator of which shall be the total number of Common Shares outstanding immediately prior to such time, and the number of Rights that shall thereafter be issued with respect to each Common Share or share of such other capital stock that shall become outstanding thereafter prior to the Distribution Date shall be equal to the total number of outstanding Rights immediately after such event (as adjusted pursuant to this clause (1)) divided by the total number of outstanding Common Shares or shares of such other capital stock immediately after such event (subject to further adjustment pursuant to the provisions of this Agreement); (2) 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 shall be adjusted so that the Purchase Price thereafter shall equal the result obtained by dividing the Purchase Price in effect immediately prior to such time by the Exchange Ratio; 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 such Right; and (3) the number of Preferred Shares or shares of such other capital stock issuable upon the exercise of each Right shall remain unchanged immediately after such event, but, in the event of a reclassification, the kind of shares issuable upon the exercise of each Right immediately after such reclassification shall be appropriately adjusted. If an event occurs which would require an adjustment under both this 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 of this Agreement, in the event a Triggering Event shall have occurred, then promptly following such Triggering Event, proper provision shall be made so that each holder of a Right, except as provided in
Section 7(e) hereof, shall thereafter have the right to receive for each Right, upon exercise thereof in accordance with the terms of this Agreement and payment of the then-current Total Exercise Price, in lieu of a

13

number of one-thousandths of a Preferred Share, such number of Common Shares of the Company as shall equal the result obtained by multiplying the then-current Purchase Price by the then number of one-thousandths of a Preferred Share for which a Right was exercisable (or would have been exercisable if the Distribution Date had occurred) immediately prior to the first occurrence of a Triggering Event, and dividing that product by 50% of the current per share market price (determined pursuant to Section 11(d) hereof) for Common Shares on the date of occurrence of the Triggering Event (such number of shares being hereinafter referred to as the "Adjustment Shares").

(iii) In lieu of issuing Common Shares in accordance with Section 11(a)(ii) hereof, the Company may, if the Board of Directors determines that such action is necessary or appropriate and not contrary to the interest of holders of Rights (and, in the event that the number of Common Shares which are authorized by the Company's Certificate of Incorporation but not outstanding or reserved for issuance for purposes other than upon exercise of the Rights are not sufficient to permit the exercise in full of the Rights, or if any necessary regulatory approval for such issuance has not been obtained by the Company, the Company shall): (A) determine the excess of (1) the value of the Common Shares issuable upon the exercise of a Right (the "Current Value") over (2) the Purchase Price (such excess, the "Spread") and (B) with respect to each Right, make adequate provision to substitute for such Common Shares, upon exercise of the Rights, (1) cash, (2) a reduction in the Purchase Price, (3) other equity securities of the Company (including, without limitation, shares or units of shares of any series of preferred stock which the Board of Directors of the Company has deemed to have the same value as Common Shares (such shares or units of shares of preferred stock are herein called "common stock equivalents")), except to the extent that the Company has not obtained any necessary stockholder or regulatory approval for such issuance, (4) debt securities of the Company, except to the extent that the Company has not obtained any necessary stockholder or regulatory approval for such issuance, (5) other assets or (6) any combination of the foregoing, having an aggregate value equal to the Current Value, where such aggregate value has been determined by the Board of Directors of the Company based upon the advice of a nationally recognized investment banking firm selected by the Board of Directors of the Company; PROVIDED, HOWEVER, if the Company shall not have made adequate provision to deliver value pursuant to clause (B) above within thirty (30) days following the later of (x) the first occurrence of a Triggering Event and (y) the date on which the Company's right of redemption pursuant to Section 23(a) expires (the later of
(x) and (y) being referred to herein as the "Section 11(a)(ii) Trigger Date"), then the Company shall be obligated to deliver, upon the surrender for exercise of a Right and without requiring payment of the Purchase Price, Common Shares (to the extent available), except to the extent that the Company has not obtained any necessary stockholder or regulatory approval for such issuance, and then, if necessary, cash, which shares and/or cash have an aggregate value equal to the Spread. If the Board of Directors of the Company shall determine in good faith that it is likely that sufficient additional Common Shares could be authorized for issuance upon exercise in full of the Rights or that any necessary regulatory approval for such issuance will be obtained, the thirty
(30) day period set forth above may be extended to the extent necessary, but not more than ninety (90) days after the Section 11(a)(ii) Trigger Date, in order that the Company may seek stockholder approval for the authorization of such additional shares or take action to obtain such regulatory approval (such period, as it may be extended, the "Substitution Period"). To the extent that the Company determines that some action need be taken pursuant to the first and/or second sentences of this

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Section 11(a)(iii), the Company (x) shall provide, subject to Section 7(e) hereof, that such action shall apply uniformly to all outstanding Rights and (y) may suspend the exercisability of the Rights until the expiration of the Substitution Period in order to seek any authorization of additional shares, to take any action to obtain any required regulatory approval and/or to decide the appropriate form of distribution to be made pursuant to such first sentence and to determine the value thereof. 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, as well as a public announcement at such time as the suspension is no longer in effect. For purposes of this Section 11(a)(iii), the value of the Common Shares shall be the current per share market price (as determined pursuant to Section 11(d) hereof) of the Common Shares on the Section
11(a)(ii) Trigger Date and the value of any "common stock equivalent" shall be deemed to have the same value as the Common Shares on such date.

(b) In case the Company shall, at any time after the date of this Agreement, fix a record date for the issuance of rights, options or warrants to all holders of Common Shares or of any class or series of Equivalent Shares entitling such holders (for a period expiring within forty-five (45) calendar days after such record date) to subscribe for or purchase Common Shares or Equivalent Shares or securities convertible into Common Shares or Equivalent Shares at a price per share (or having a conversion price per share, if a security convertible into Common Shares or Equivalent Shares) less than the then current per share market price of the Common Shares or Equivalent Shares (as defined in Section 11(d)) on such record date, then, in each such case, 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 Common Shares and Equivalent Shares (if any) outstanding on such record date, plus the number of Common Shares or Equivalent Shares, as the case may be, which the aggregate offering price of the total number of Common Shares or Equivalent Shares, as the case may be, 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 Common Shares and Equivalent Shares (if any) outstanding on such record date, plus the number of additional Common Shares or Equivalent Shares, as the case may be, to be offered for subscription or purchase (or into which the convertible securities so to be offered are initially convertible). 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 and shall be binding on the Rights Agent and the holders of the Rights. Common Shares and Equivalent Shares owned by 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, at any time after the date of this Agreement, fix a record date for the making of a distribution to all holders of the Common Shares or of any class or series of Equivalent 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, if any, or a

15

dividend payable in Common Shares) or subscription rights, options or warrants (excluding those referred to in Section 11(b)), then, in each such case, 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 current market price (as determined pursuant to Section 11(d) hereof) of a Common Share or an Equivalent Share 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 cash, assets or evidences of indebtedness so to be distributed or of such subscription rights or warrants applicable to a Common Share or Equivalent Share, as the case may be, and the denominator of which shall be such current market price (as determined pursuant to Section 11(d) hereof) of a Common Share or Equivalent Share on such record date. 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 be adjusted to be the Purchase Price which would have been in effect if such record date had not been fixed.

(d) For the purpose of any computation hereunder, other than computations made pursuant to Section 11(a)(iii) hereof, the "current per share market price" of any security (a "Security" for the purpose of this Section 11(d)) on any date shall be deemed to be the average of the daily closing prices per share of such Security for the thirty (30) consecutive Trading Days (as such term is hereinafter defined) immediately prior to such date, and for purposes of computations made pursuant to Section 11(a)(iii) hereof, the "current per share market price" of any Security on any date shall be deemed to be the average of the daily closing prices per share of such Security for the ten (10) consecutive Trading Days 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 (i) a dividend or distribution on such Security payable in shares of such Security or securities convertible into such shares or (ii) any subdivision, combination or reclassification of such Security, and prior to the expiration of the requisite thirty (30) Trading Day or ten (10) Trading Day period, 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 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, if the Security is not listed or admitted to trading on any national securities exchange, the last sale price or, if such last sale price is not reported, 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. If on any such date no market maker is making a market in the Common Shares, the fair value of such shares on such date as determined in good faith by the Board of Directors of the Company shall be used. The term

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"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. If the Common Shares are not 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 and shall be conclusive for all purposes.

(e) Anything herein to the contrary notwithstanding, 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 ten-thousandth of a Common Share or other share or one hundred-thousandth of a Preferred Share, 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 earlier of (i) three (3) years from the date of the transaction which requires such adjustment or (ii) the Expiration Date.

(f) If as a result of an adjustment made pursuant to Section 11(a) or 13(a) hereof, the holder of any Right thereafter exercised shall become entitled to receive any shares of capital stock other than Preferred Shares, thereafter the number of such other shares so receivable upon exercise of any Right and if required, the Purchase Price thereof, 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 Common Shares contained in Sections 11(a), (b),
(c), (e), (h), (i), (j), (k), (l) and (m), and the provisions of Sections 7, 9, 10, 13 and 14 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-thousandths 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), upon each adjustment of the Purchase Price as a result of the calculations made in Section 11(b), 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 Preferred Shares (calculated to the nearest one hundred-thousandth of a share) obtained by (i) multiplying (x) the number of Preferred Shares 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 as a result of the calculations made in Section 11(b) to adjust the number of Rights, in substitution for any adjustment in the number of Preferred Shares purchasable upon the exercise of a Right. Each of the Rights outstanding after such adjustment of the number of

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Rights shall be exercisable for the number of one-thousandths 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 hundred-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 made. This record date may be the date on which the Purchase Price is adjusted or any day thereafter, but, if the Rights Certificates have been issued, shall be at least ten (10) days later than the date of the public announcement. If Rights 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 Rights Certificates on such record date Rights 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 Rights Certificates held by such holders prior to the date of adjustment, and upon surrender thereof, if required by the Company, new Rights Certificates evidencing all the Rights to which such holders shall be entitled after such adjustment. Rights Certificates so to be distributed shall be issued, executed and countersigned in the manner provided for herein (and may bear, at the option of the Company, the adjusted Purchase Price) and shall be registered in the names of the holders of record of Rights 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 Preferred Shares issuable upon the exercise of the Rights, the Rights Certificates theretofore and thereafter issued may continue to express the Purchase Price per one one-thousandth of a Preferred Share and the number of one-thousandths of a Preferred Share which were expressed in the initial Rights Certificates issued hereunder.

(k) Before taking any action that would cause an adjustment reducing the Purchase Price below the par or stated value, if any, of the number of one-thousandths of a Preferred Share 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 as fully paid and nonassessable shares such number of one-thousandths of a Preferred Share 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 number of one-thousandths of a Preferred Share and other capital stock or securities of the Company, if any, issuable upon such exercise over and above the number of one-thousandths of a Preferred Share 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 bill or other appropriate instrument evidencing such holder's right to receive such additional shares (fractional or otherwise) upon the occurrence of the event requiring such adjustment.

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(m) Anything in this Section 11 to the contrary notwithstanding, prior to the Distribution Date, 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 (i) consolidation or subdivision of the Preferred or Common Shares, (ii) issuance wholly for cash of any Preferred or Common Shares at less than the current market price, (iii) issuance wholly for cash of Preferred or Common Shares or securities which by their terms are convertible into or exchangeable for Preferred or Common Shares, (iv) stock dividends or (v) issuance of rights, options or warrants referred to in this
Section 11, hereafter made by the Company to holders of its Preferred or Common Shares shall not be taxable to such stockholders.

(n) The Company covenants and agrees that it shall not, at any time after the Distribution Date, effect or permit to occur any Triggering Event or Section 13 Event, if (i) at the time or immediately after such Triggering Event or Section 13 Event there are any rights, warrants or other instruments or securities outstanding or agreements in effect which would substantially diminish or otherwise eliminate the benefits intended to be afforded by the Rights or (ii) prior to, simultaneously with or immediately after such Section 13 Event, the stockholders of the Person who constitutes, or would constitute, the "Principal Party" for purposes of Section 13(b) hereof shall have received a distribution of Rights previously owned by such Person or any of its Affiliates and Associates.

(o) The Company covenants and agrees that, after the Distribution Date, it will not, except as permitted by Sections 23, 24 or 27 hereof, take (or permit to be taken) any action if at the time such action is taken it is reasonably foreseeable that such action will diminish substantially or otherwise eliminate the benefits intended to be afforded by the Rights.

(p) Anything in this Agreement to the contrary notwithstanding, 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 (by reverse stock split or otherwise) 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), then, in each such event, except as otherwise provided in this Section 11 and
Section 7(e) hereof: (1) each of the Rights outstanding at the time of the record date for such dividend or the effective date of such subdivision, combination or reclassification shall be proportionately adjusted to that number of Rights (calculated to the nearest one ten-thousandth (1/10,000) of a Right) equal to a fraction (the "Exchange Fraction"), the numerator of which shall be the total number of Preferred Shares or shares of capital stock issued in such reclassification of the Preferred Shares outstanding immediately following such time and the denominator of which shall be the total number of Preferred Shares outstanding immediately prior to such time, and the number of Rights that shall thereafter be issued with respect to each Common Share or share of other capital stock that shall be issued in a reclassification of the Common Shares prior to the Distribution Date shall be equal to the total number of outstanding Rights immediately after such event (as adjusted pursuant to this clause (1)) divided by the total number of outstanding Common Shares or shares of such other capital stock immediately after such event (subject to further adjustment pursuant to the provisions of this Agreement); (2) the Purchase Price in effect at the time of the record date for

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such dividend or of the effective date of such subdivision, combination or reclassification shall be adjusted so that the Purchase Price thereafter shall equal the result obtained by dividing the Purchase Price in effect immediately prior to such time by the Exchange Fraction; 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 such Right; and (3) the number of one-thousandths of a Preferred Share or share of such other capital stock issuable upon the exercise of each Right shall remain unchanged immediately after such event, but, in the event of a reclassification, the kind of shares issuable upon the exercise of each Right immediately after such reclassification shall be adjusted to be the kind of shares of such other capital stock issued in such reclassification, rather than Preferred Shares.

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 of the facts accounting for such adjustment, (b) file with the Rights Agent and with each transfer agent for the Preferred Shares a copy of such certificate and (c) mail a brief summary thereof to each holder of a Rights Certificate in accordance with Section 26 hereof. Notwithstanding the foregoing sentence, the failure of the Company to make such certification or give such notice shall not affect the validity of such adjustment or the force or effect of the requirement for such adjustment. The Rights Agent shall be fully protected in relying on any such certificate and on any adjustment contained therein and shall not be deemed to have knowledge of such 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, directly or indirectly:

(i) the Company shall consolidate with, or merge with and into, any other Person (other than a Subsidiary of the Company in a transaction the principal purpose of which is to change the state of incorporation of the Company or which complies with Section 11(o) hereof);

(ii) any Person (other than a Subsidiary of the Company in a transaction that complies with Section 11(o) hereof) shall consolidate with the Company, or merge with and into the Company and the Company shall be the continuing or surviving corporation of such consolidation or merger; or

(iii) the Company shall sell or otherwise transfer (or one or more of its Subsidiaries shall sell or otherwise transfer), in one or more transactions, assets or earning power aggregating 50% or more of the assets or earning power of the Company and its Subsidiaries (taken as a whole) to any other Person or Persons (other than the Company or one or more of its wholly owned Subsidiaries in one or more transactions, each of which complies with Section 11(o) hereof), then, and in each such case, proper provision shall be made so that

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(A) each holder of a Right (except as otherwise provided herein) shall thereafter have the right to receive, upon the exercise thereof in accordance with the terms of this Agreement, such number of validly authorized and issued, fully paid and nonassessable Common Shares of the Principal Party (as hereinafter defined), free of any liens, encumbrances, rights of first refusal or other adverse claims, as shall be equal to the result obtained by (1) multiplying the then current Purchase Price by the number of one-thousandths of a Preferred Share for which a Right was exercisable immediately prior to the first occurrence of a Section 13 Event (or, if a Triggering Event has occurred prior to the first occurrence of a Section 13 Event, multiplying the number of such one-thousandths of a Preferred Share for which a Right was exercisable immediately prior to the first occurrence of a Triggering Event by the Purchase Price in effect immediately prior to such first occurrence) and (2) dividing that product (which, following the first occurrence of a Section 13 Event, shall be referred to as the "Total Exercise Price" for each Right and for all purposes of this Agreement) by 50% of the current per share market price (determined pursuant to Section 11(d) hereof) of the Common Shares of such Principal Party on the date of consummation of such Section 13 Event;

(B) such Principal Party shall thereafter be liable for, and shall assume, by virtue of such Section 13 Event, all the obligations and duties of the Company pursuant to this Agreement;

(C) 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 only to such Principal Party following the first occurrence of a
Section 13 Event;

(D) such Principal Party shall take such steps (including, but not limited to, the reservation of a sufficient number of its Common Shares) in connection with the consummation of any such transaction 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, in the case of any transaction described in clause (i), (ii) or (iii) of Section 13(a), the Person or Acquiring Person referred to therein (or such Person's or Acquiring Person's successor, including, if applicable, the Company, if it is the surviving corporation), PROVIDED, HOWEVER, that in any such case, (i) if such Person is a direct or indirect Subsidiary of another Person, "Principal Party" shall refer to such other Person and (ii) in case such Person is a Subsidiary, directly or indirectly, of more than one Person, "Principal Party" shall refer to whichever of such Persons is the issuer of the Common Shares having the greatest aggregate value, and PROVIDED, FURTHER, that for purposes of transactions described in clause (iii) hereof, "Principal Party" shall refer to that Person receiving the greatest portion of the assets or earning power transferred pursuant to such transaction or transactions.

(c) If, for any reason, the Rights cannot be exercised for Common Shares of such Principal Party as provided in Section 13(a), then each holder of Rights shall have the right to exchange its Rights for cash from such Principal Party in an amount equal to the number of Common Shares that it would otherwise be entitled to purchase times 50% of the current per share market price, as determined pursuant to Section 11(d) hereof, of such Common Shares of

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such Principal Party. If, for any reason, the foregoing formulation cannot be applied to determine the cash amount into which the Rights are exchangeable, then the Board of Directors, based upon the advice of one or more nationally recognized investment banking firms, and based upon the total value of the Company, shall determine such amount reasonably and with good faith to the holders of Rights. Any such determination shall be final and binding on the Rights Agent.

(d) The Company shall not consummate any Section 13 Event unless the Principal Party shall have a sufficient number of authorized Common 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 such issuer shall have executed and delivered to the Rights Agent a supplemental agreement confirming that such Principal Party shall, upon consummation of such Section 13 Event, assume this Agreement in accordance with Sections 13(a) and (b) hereof, that all rights of first refusal or preemptive rights in respect of the issuance of Common Shares of such Principal Party upon exercise of outstanding Rights have been waived, that there are no rights, warrants, instruments or securities outstanding or any agreements or arrangements which, as a result of the consummation of such transaction, would eliminate or substantially diminish the benefits intended to be afforded by the Rights and that such transaction shall not result in a default by such Principal Party under this Agreement, and further providing that, as soon as practicable after the date of such Section 13 Event, such Principal Party will:

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

(ii) use its best efforts to list (or continue the listing of) the Rights and the securities purchasable upon exercise of the Rights on a national securities exchange or to meet the eligibility requirements for quotation on Nasdaq; and

(iii) deliver to holders of the Rights historical financial statements for such Principal Party which comply in all respects with the requirements for registration on Form 10 (or any successor form) under the Exchange Act.

In the event that at any time after the occurrence of a Triggering Event some or all of the Rights shall not have been exercised at the time of a transaction described in this Section 13, the Rights which have not theretofore been exercised shall thereafter be exercisable in the manner described in
Section 13(a) (without taking into account any prior adjustment required by
Section 11(a)(ii)).

(e) The provisions of this Section 13 shall similarly apply to successive mergers or consolidations or sales or other transfers.
SECTION 14. ......FRACTIONAL RIGHTS AND FRACTIONAL SHARES.

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(a) The Company shall not be required to issue fractions of Rights or to distribute Rights Certificates which evidence fractional Rights. In lieu of such fractional Rights, there shall be paid to the registered holders of the Rights 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, as determined pursuant to the second sentence of
Section 11(d) hereof.

(b) The Company shall not be required to issue fractions of Preferred Shares (other than fractions that are integral multiples of one one-thousandth of a Preferred Share) upon exercise of the Rights or to distribute certificates which evidence fractional Preferred Shares (other than fractions that are integral multiples of one one-thousandth of a Preferred Share). In lieu of fractional Preferred Shares that are not integral multiples of one one-thousandth of a Preferred Share, the Company shall pay to the registered holders of Rights 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 a Common Share. For purposes of this Section 14(b), the current market value of a Common Share shall be the closing price of a Common Share (as determined pursuant to the second sentence of Section 11(d) hereof) for the Trading Day immediately prior to the date of such exercise.

(c) The holder of a Right by the acceptance of the Right expressly waives his or her right to receive any fractional Rights or any fractional shares upon exercise of a Right.

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
Section 18 hereof, are vested in the respective registered holders of the Rights Certificates (and, prior to the Distribution Date, the registered holders of the Common Shares); and any registered holder of any Rights 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 Rights Certificate (or, prior to the Distribution Date, of the Common Shares), may, in his or her own behalf and for his or her own benefit, enforce, and may institute and maintain any suit, action or proceeding against the Company to enforce, or otherwise act in respect of, his or her right to exercise the Rights evidenced by such Rights Certificate in the manner provided in such Rights 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.

SECTION 16. ......AGREEMENT OF RIGHTS 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;

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(b) after the Distribution Date, the Rights Certificates are transferable only on the registry books of the Rights Agent if surrendered at the principal office or offices of the Rights Agent designated for such purposes, duly endorsed or accompanied by a proper instrument of transfer and with the appropriate forms and certificates fully executed; and

(c) subject to Sections 6(a) and 7(f) hereof, the Company and the Rights Agent may deem and treat the person in whose name the Rights 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 Rights 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. RIGHTS CERTIFICATE HOLDER NOT DEEMED A STOCKHOLDER. No holder, as such, of any Rights 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 Rights Certificate be construed to confer upon the holder of any Rights 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, or otherwise, until the Right or Rights evidenced by such Rights Certificate shall have been exercised in accordance with the provisions hereof.

SECTION 18. CONCERNING THE RIGHTS AGENT.

(a) 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 gross negligence, bad faith or willful misconduct (each as determined by the final non-appealable order of a court of competent jurisdiction) 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. Anything in this Agreement to the contrary notwithstanding, in no event shall the Rights Agent be liable for special, punitive, indirect or consequential loss or damage of any kind whatsoever (including but not limited to lost profits), even if the Rights Agent has been advised of the likelihood of such loss or damage and regardless of the form of the action. Anything to the contrary herein notwithstanding, the Rights Agent's liability under this Agreement shall be limited to the amount of annual fees received by the Rights Agent hereunder.

(b) 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

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Agreement in reliance upon any Rights 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.

(a) Any Person into which the Rights Agent or any successor Rights Agent may be merged or with which it may be consolidated, or any Person resulting from any merger or consolidation to which the Rights Agent or any successor Rights Agent shall be a party, or any Person succeeding to the 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, HOWEVER, that such Person 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 Rights 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 Rights Certificates so countersigned; and in case at that time any of the Rights Certificates shall not have been countersigned, any successor Rights Agent may countersign such Rights 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 Rights Certificates shall have the full force provided in the Rights Certificates and in this Agreement.

(b) In case at any time the name of the Rights Agent shall be changed and at such time any of the Rights Certificates shall have been countersigned but not delivered, the Rights Agent may adopt the countersignature under its prior name and deliver Rights Certificates so countersigned; and in case at that time any of the Rights Certificates shall not have been countersigned, the Rights Agent may countersign such Rights Certificates either in its prior name or in its changed name; and in all such cases such Rights Certificates shall have the full force provided in the Rights 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 Rights Certificates, by their acceptance thereof, shall be bound:

(a) The Rights Agent may consult with legal counsel (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 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 (including, without

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limitation, the identity of any Acquiring Person and the determination of "current per share market price") 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, any Vice President, the Chief Financial Officer, the Secretary or any Assistant 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 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 gross negligence, bad faith or willful misconduct (each as determined by the final non-appealable order of a court of competent jurisdiction).

(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 Rights 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 Rights 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 Rights Certificate; nor shall it be responsible for any change in the exercisability of the Rights 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, 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 Rights Certificates after receipt by the Rights Agent of a certificate furnished pursuant to Section 12 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 Rights 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, any Vice President, the Chief Financial Officer, the Secretary or any Assistant Secretary 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 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

26

action proposed to be taken or omitted by the Rights Agent under this Agreement and the date on and/or after which such action shall be taken or such omission shall be effective. The Rights Agent shall not be liable for any action taken by, or omission of, the Rights Agent in accordance with a proposal included in any such application on or after the date specified in such application (which date shall not be less than five (5) Business Days after the date any officer of the Company actually receives such application, unless any such officer shall have consented in writing to an earlier date) unless, prior to taking any such action (or the effective date in the case of an omission), the Rights Agent shall have 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 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 no gross negligence, willful misconduct or bad faith (each as determined by the final non-appealable order of a court of competent jurisdiction) 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 Rights 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 either not been completed or indicates an affirmative response to clause 1 and/or 2 thereof, the Rights Agent shall not take any further action with respect to such requested exercise or 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 thirty (30) days' notice in writing mailed to the Company and to each transfer agent of the Preferred Shares and the Common Shares by registered or certified mail, and to the holders of the Rights Certificates by first-class mail. The Company may remove the Rights Agent or any successor Rights Agent upon thirty (30) days' notice in writing, mailed to the Rights Agent or successor Rights Agent, as the case may be, and to each transfer agent of the Preferred Shares and the Common Shares by registered or certified mail, and to the holders of the Rights 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

27

shall fail to make such appointment within a period of thirty (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 Rights Certificate (who shall, with such notice, submit his or her Rights Certificate for inspection by the Company), then the registered holder of any Rights 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 Person organized and doing business under the laws of the United States or of any state of the United States, in good standing, which is authorized under such laws to exercise corporate trust or stockholder services powers and is subject to supervision or examination by 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 of the Preferred Shares and the Common Shares, and mail a notice thereof in writing to the registered holders of the Rights 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 RIGHTS CERTIFICATES. Notwithstanding any of the provisions of this Agreement or of the Rights to the contrary, the Company may, at its option, issue new Rights 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 Rights 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 redemption or expiration of the Rights, 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 or upon the exercise, conversion or exchange of securities hereinafter issued by the Company and (b) may, in any other case, if deemed necessary or appropriate by the Board of Directors of the Company, issue Rights Certificates representing the appropriate number of Rights in connection with such issuance or sale; PROVIDED, HOWEVER, that (i) no such Rights Certificate shall be issued and this sentence shall be null and void ab initio if, and to the extent that, such issuance or this sentence would create a significant risk of or result in material adverse tax consequences to the Company or the Person to whom such Rights Certificate would be issued or would create a significant risk of or result in such options' or employee plans' or arrangements' failing to qualify for otherwise available special tax treatment and (ii) no such Rights 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.

28

(a) The Company may, at its option and with the approval of the Board of Directors, at any time prior to the Close of Business on the earlier of (i) the tenth day following the Shares Acquisition Date or such later date as may be determined by action of the Company's Board of Directors and publicly announced by the Company or (ii) the Final Expiration Date, redeem all but not less than all the then outstanding Rights at a redemption price of $0.01 per Right, appropriately adjusted to reflect any stock split, stock dividend or similar transaction occurring after the date hereof (such redemption price being herein referred to as the "Redemption Price") and the Company may, at its option, pay the Redemption Price either in Common Shares (based on the current per share market price thereof (as determined pursuant to Section 11(d) hereof) at the time of redemption) or cash. Such redemption of the Rights by the Company may be made effective at such time, on such basis and with such conditions as the Board of Directors in its sole discretion may establish.

(b) Immediately upon the action of the Board of Directors of the Company ordering the redemption of the Rights, evidence of which shall have been filed with the Rights Agent, 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 effect the validity of such redemption. Within ten (10) days after the action of the Board of Directors ordering the redemption of the Rights, the Company shall give notice of such redemption to the Rights Agent and the holders of the then outstanding Rights by mailing such notice to all such holders 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. Any notice which is mailed in the manner herein 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.

SECTION 24. EXCHANGE.

(a) Subject to applicable laws, rules and regulations, and subject to subsection
(c) below, the Company may, at its option, by the Board of Directors, at any time after the occurrence of a Triggering Event, 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 7(e) 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 "Ratio of Exchange"). 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.

29

(b) Immediately upon the action of the Board of Directors ordering the exchange of any Rights pursuant to subsection (a) of this Section 24 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 Ratio of Exchange. The Company shall 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 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. Any notice which is 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 7(e) hereof) held by each holder of Rights.

(c) In the event that there shall not be sufficient Common Shares issued but not outstanding or authorized but unissued to permit any exchange of Rights as contemplated in accordance with Section 24(a), the Company shall either take such action as may be necessary to authorize additional Common Shares for issuance upon exchange of the Rights or alternatively, at the option of a majority of the Board of Directors, with respect to each Right (i) pay cash in an amount equal to the Current Value (as hereinafter defined), in lieu of issuing Common Shares in exchange therefor, or (ii) issue debt or equity securities or a combination thereof, having a value equal to the Current Value, in lieu of issuing Common Shares in exchange for each such Right, where the value of such securities shall be determined by a nationally recognized investment banking firm selected by the Board of Directors by majority vote of the Board of Directors, or (iii) deliver any combination of cash, property, Common Shares and/or other securities having a value equal to the Current Value in exchange for each Right. For purposes of this Section 24(c) only, the Current Value shall mean the product of the current per share market price of Common Shares (determined pursuant to Section 11(d) on the date of the occurrence of the event described above in subparagraph (a)) multiplied by the number of Common Shares for which the Right otherwise would be exchangeable if there were sufficient shares available. To the extent that the Company determines that some action need be taken pursuant to clauses (i), (ii) or (iii) of this Section
24(c), the Board of Directors may temporarily suspend the exercisability of the Rights for a period of up to sixty (60) days following the date on which the event described in Section 24(a) shall have occurred, in order to seek any authorization of additional Common Shares and/or to decide the appropriate form of distribution to be made pursuant to the above provision and to determine the value thereof. 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, there shall be paid to the registered holders of the Rights 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 per share market value of a whole Common Share (as determined pursuant to the second sentence of Section 11(d) hereof).

30

(e) The Company may, at its option, by majority vote of the Board of Directors, at any time before any Person has become an Acquiring Person, exchange all or part of the then outstanding Rights for rights of substantially equivalent value, as determined reasonably and with good faith by the Board of Directors, based upon the advice of one or more nationally recognized investment banking firms.

(f) Immediately upon the action of the Board of Directors ordering the exchange of any Rights pursuant to subsection (e) of this Section 24 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 rights in exchange therefor as has been determined by the Board of Directors in accordance with subsection (e) above. The Company shall 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 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 transfer agent for the Common Shares of the Company. Any notice which is 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 Rights will be effected.

SECTION 25. NOTICE OF CERTAIN EVENTS.

(a) In case the Company shall propose to effect or permit to occur any Triggering Event described in Section 11(a)(ii)(A) or 11(a)(ii)(B) or a Section 13 Event, the Company shall give notice thereof to each holder of Rights in accordance with Section 26 hereof at least twenty (20) days prior to occurrence of such Triggering Event or such Section 13 Event.

(b) In case any Triggering Event or Section 13 Event shall occur, then, in any such case, the Company shall as soon as practicable thereafter give to each holder of a Rights Certificate, in accordance with Section 26 hereof, a notice of the occurrence of such event, which shall specify the event and the consequences of the event to holders of Rights under Sections 11(a)(ii) and 13 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 Rights 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:

LIGAND PHARMACEUTICALS INCORPORATED
10275 Science Center Drive
San Diego, CA 92121
Attn: President

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 Rights 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:

31

MELLON INVESTOR SERVICES LLC
Overpeck Centre
85 Challenger Road
Ridgefield, NJ 07606
Attention: Stock Transfer Department

Notices or demands authorized by this Agreement to be given or made by the Company or the Rights Agent to the holder of any Rights 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 may supplement or amend this Agreement in any respect without the approval of any holders of Rights and the Rights Agent shall, if the Company so directs, execute such supplement or amendment. From and after the Distribution Date, the Company and the Rights Agent may from time to time supplement or amend this Agreement without the approval of any holders of Rights 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, (iii) shorten or lengthen any time period hereunder or (iv) to change or supplement the provisions hereunder in any manner that the Company may deem necessary or desirable and that shall not adversely affect the interests of the holders of Rights (other than an Acquiring Person or an Affiliate or Associate of an Acquiring Person); PROVIDED, this Agreement may not be supplemented or amended to lengthen, pursuant to clause (iii) of this sentence, (A) a time period relating to when the Rights may be redeemed at such time as the Rights are not then redeemable or (B) any other time period unless such lengthening is for the purpose of protecting, enhancing or clarifying the rights of, and/or the benefits to, the holders of Rights. Upon the delivery of a certificate from an appropriate officer of the Company that 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. 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. 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.

SECTION 29. DETERMINATIONS 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 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. 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,

32

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 Company, the Rights Agent, the holders of the Rights Certificates and all other parties and
(y) not subject the Board of Directors to any liability to the holders of the Rights.

SECTION 30. BENEFITS OF THIS AGREEMENT. Nothing in this Agreement shall be construed to give to any Person other than the Company, the Rights Agent and the registered holders of the Rights 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 Rights 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; PROVIDED, HOWEVER, that notwithstanding anything in this Agreement to the contrary, if any such term, provision, covenant or restriction is held by such court or authority to be invalid, void or unenforceable and the Board of Directors of the Company determines in its good faith judgment that severing the invalid language from this Agreement would adversely affect the purpose or effect of this Agreement, the right of redemption set forth in Section 23 hereof shall be reinstated and shall not expire until the close of business on the tenth day following the date of such determination by the Board of Directors.

SECTION 32. GOVERNING LAW. This Agreement and each Right and each Rights 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.

[Remainder of This Page Intentionally Left Blank]

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

"COMPANY"                              LIGAND PHARMACEUTICALS INCORPORATED

                                       By:  /s/ Paul V. Maier
                                          -------------------------------------
                                       Name: Paul V. Maier
                                       Title: Senior Vice President and CFO


"RIGHTS AGENT"                         MELLON INVESTOR SERVICES LLC


                                       By:  /s/ Thomas L. Cooper
                                          -------------------------------------
                                       Name:  Thomas L. Cooper
                                       Title: Client Relationship Executive

34

EXHIBIT A

FORM OF RIGHTS CERTIFICATE

Certificate No. R- _____ Rights

NOT EXERCISABLE AFTER OCTOBER 13, 2016 OR EARLIER IF TERMINATED BY THE COMPANY OR IF THE COMPANY EXCHANGES THE RIGHTS PURSUANT TO THE RIGHTS AGREEMENT. THE RIGHTS ARE SUBJECT TO REDEMPTION, AT THE OPTION OF THE COMPANY, AT $0.01 PER RIGHT ON THE TERMS SET FORTH IN THE RIGHTS AGREEMENT. UNDER CERTAIN CIRCUMSTANCES, RIGHTS BENEFICIALLY OWNED BY AN ACQUIRING PERSON OR AN AFFILIATE OR ASSOCIATE OF AN ACQUIRING PERSON (AS SUCH TERMS ARE DEFINED IN THE RIGHTS AGREEMENT) AND ANY SUBSEQUENT HOLDER OF SUCH RIGHTS MAY BECOME NULL AND VOID.
[THE RIGHTS REPRESENTED BY THIS RIGHTS 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 RIGHTS CERTIFICATE AND THE RIGHTS REPRESENTED HEREBY MAY BECOME NULL AND VOID IN THE CIRCUMSTANCES SPECIFIED IN SECTION 7(E) OF SUCH RIGHTS AGREEMENT.](1)

RIGHTS CERTIFICATE

LIGAND PHARMACEUTICALS INCORPORATED

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 2006 Preferred Shares Rights Agreement dated as of October 13, 2006, as amended from time to time (the "Rights Agreement"), between Ligand Pharmaceuticals Incorporated, a Delaware corporation (the "Company"), and Mellon Investor Services LLC ( 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., New York time, on October 13, 2016 at the office of the Rights Agent designated for such purpose, or at the office of its successor as Rights Agent, one one-thousandth of a fully paid non-assessable share of Series A Participating Preferred Stock, par value $.001 per share, (the "Preferred Shares"), of the Company, at a purchase price of $0.01 per one-thousandth of a Preferred Share (the "Purchase Price"), upon presentation and surrender of this Rights Certificate with the Form of Election to Purchase and related Certificate duly executed. The number of Rights evidenced by this Rights Certificate (and the number of one-thousandths of a Preferred Share which may be purchased upon exercise hereof) set forth above are the number and Purchase Price as of October 31, 2006, based on the Preferred Shares as constituted at such date. As provided in the Rights Agreement, the Purchase Price and the number and kind of Common Shares or other securities

(1) * THE PORTION OF THE LEGEND IN BRACKET SHALL BE INSERTED ONLY IF APPLICABLE AND SHALL REPLACE THE PRECEDING SENTENCE.

A-1

which may be purchased upon the exercise of the Rights evidenced by this Rights Certificate are subject to modification and adjustment upon the happening of certain events.

This Rights Certificate is subject to all of the terms, provisions and conditions of the Rights Agreement, 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 Rights Certificates, which limitations of rights include the temporary suspension of the exercisability of such Rights under the specific circumstances set forth in the Rights Agreement. Copies of the Rights Agreement are on file at the principal executive offices of the Company and the above-mentioned office of the Rights Agent.

Subject to the provisions of the Rights Agreement, the Rights evidenced by this Rights Certificate (i) may be redeemed by the Company, at its option, at a redemption price of $0.01 per Right or (ii) may be exchanged by the Company in whole or in part for Common Shares, substantially equivalent rights or other consideration as determined by the Company.

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

No fractional portion of less than one one-thousandth of a Preferred Share will be issued upon the exercise of any Right or Rights evidenced hereby but in lieu thereof a cash payment will be made, as provided in the Rights Agreement.

No holder of this Rights Certificate, as such, 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 Rights Certificate shall have been exercised as provided in the Rights Agreement.

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

A-2

WITNESS the facsimile signature of the proper officers of the Company and its corporate seal. Dated as of ______________, 20__.

ATTEST:                              LIGAND PHARMACEUTICALS INCORPORATED


                                     By:
                                        ----------------------------------------
                                     Warner R. Broaddus, Vice President, General
                                     Counsel & Secretary


                                     -------------------------------------------
                                     Paul V. Maier, Senior Vice President & CFO
Countersigned:
as Rights Agent


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

A-3

FORM OF REVERSE SIDE OF RIGHTS CERTIFICATE

FORM OF ASSIGNMENT

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

FOR VALUE RECEIVED____________________hereby sells, assigns and transfers unto_________________________________________________________________ (Please print name and address of transferee) this Rights Certificate, together with all right, title and interest therein, and does hereby irrevocably constitute and appoint __________________________ Attorney, to transfer the within Rights Certificate on the books of the within-named Company, with full power of substitution.

Dated: _______________, 20__

Signature

Signature Guaranteed:

Signatures must be guaranteed by a member firm of a registered national securities exchange, a member of the National Association of Securities Dealers, Inc., or a commercial bank or trust company having an office or correspondent in the United States.

CERTIFICATE

The undersigned hereby certifies by checking the appropriate boxes that:

(i) this Rights Certificate [ ] is [ ] is not being sold, assigned and transferred by or on behalf of a Person who is or was an Acquiring Person, or an Affiliate or Associate of any such Person (as such terms are defined in the Rights Agreement);

(ii) after due inquiry and to the best knowledge of the undersigned, it [ ] did [ ] did not acquire the Rights evidenced by this Rights Certificate from any Person who is, was or subsequently became an Acquiring Person or an Affiliate or Associate of any such Person.

Dated: _______________, 20__

Signature

Signature Guaranteed:

Signatures must be guaranteed by a member firm of a registered national securities exchange, a member of the National Association of Securities Dealers, Inc., or a commercial bank or trust company having an office or correspondent in the United States.

A-4

FORM OF REVERSE SIDE OF RIGHTS CERTIFICATE -- CONTINUED

FORM OF ELECTION TO PURCHASE

(To be executed if holder desires to
exercise the Rights Certificate)

The undersigned hereby irrevocably elects to exercise__________________ Rights represented by this Rights Certificate to purchase the number of one-thousandths of a Preferred Share issuable upon the exercise of such Rights and requests that certificates for such number of one-thousandths of a Preferred Share 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 Rights Certificate, a new Rights 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: _______________, 20__

Signature

Signature Guaranteed:

Signatures must be guaranteed by a member firm of a registered national securities exchange, a member of the National Association of Securities Dealers, Inc., or a commercial bank or trust company having an office or correspondent in the United States.

A-5

CERTIFICATE

The undersigned hereby certifies by checking the appropriate boxes

(1) the Rights evidenced by this Rights Certificate [ ] are [ ] are not being exercised by or on behalf of a Person who is or was an Acquiring Person or an Affiliate or Associate of any such Person (as such terms are defined in the Rights Agreement);

(2) after due inquiry and to the best knowledge of the undersigned, it
[ ] did [ ] did not acquire the Rights evidenced by this Rights Certificate from any Person who is, was or subsequently became an Acquiring Person or an Affiliate or Associate of any such Person.

Dated: _________, 20__

Signature

Signature Guaranteed:

Signatures must be guaranteed by a member firm of a registered national securities exchange, a member of the National Association of Securities Dealers, Inc., or a commercial bank or trust company having an office or correspondent in the United States.

A-6

FORM OF REVERSE SIDE OF RIGHTS CERTIFICATE -- CONTINUED

The signature in the foregoing Forms of Assignment and Election must conform to the name as written upon the face of this Rights Certificate in every particular, without alteration or enlargement or any change whatsoever.

A-7

EXHIBIT B

LIGAND PHARMACEUTICALS INCORPORATED

SHAREHOLDER RIGHTS PLAN

Summary of Rights

DISTRIBUTION TRANSFER OF RIGHTS; RIGHTS CERTIFICATE:

The Board of Directors has declared a dividend of one Right for each share of Ligand Pharmaceuticals Incorporated Common Stock outstanding. Prior to the Distribution Date referred to below, the Rights will be evidenced by, and trade with, the certificates for the Common Stock. After the Distribution Date, Ligand Pharmaceuticals Incorporated (the "Company") will mail Rights certificates to the Company's stockholders and the Rights will become transferable apart from the Common Stock.

DISTRIBUTION DATE:

Rights will separate from the Common Stock and become exercisable on the tenth day (or such later date as may be determined by the Company's Board of Directors) after a person or group (a) acquires beneficial ownership of 20% or more of the Company's Common Stock or (b) announces a tender or exchange offer, the consummation of which would result in ownership by a person or group of 20% or more of the Company's Common Stock.

PREFERRED STOCK PURCHASABLE UPON EXERCISE OF RIGHTS:

After the Distribution Date, each Right will entitle the holder to purchase, for $100.00 a fraction of a share of the Company's Preferred Stock with economic terms similar to that of one share of the Company's Common Stock.

FLIP-IN:

If an acquiror (an "Acquiring Person") obtains 20% or more of the Company's Common Stock, then each Right (other than Rights owned by an Acquiring Person or its affiliates) will entitle the holder thereof to purchase, for the exercise price, a number of shares of the Company's Common Stock having a then current market value of twice the exercise price.

FLIP-OVER:

If, after the Shares Acquisition Date (defined below), (a) the Company merges into another entity, (b) an acquiring entity merges into the Company or (c) the Company sells more than 50% of the Company's assets or earning power, then each Right (other than Rights owned by an Acquiring Person or its affiliates) will entitle the holder thereof to purchase, for the exercise price, a number of shares of Common Stock of the person engaging in the transaction having a then current market value of twice the exercise price.

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EXCHANGE PROVISION:

At any time after an event triggering the flip-in or flip-over rights and prior to the acquisition by the Acquiring Person of 50% or more of the outstanding Common Stock, the Board of Directors of the Company may exchange the Rights (other than Rights owned by the Acquiring Person or its affiliates), in whole or in part, at an exchange ratio of one Common Share per Right (subject to adjustment).

REDEMPTION OF THE RIGHTS:

Rights will be redeemable at the Company's option for $0.01 per Right at any time on or prior to the tenth day (or such later date as may be determined by the Company's Board of Directors) after public announcement that a person has acquired beneficial ownership of 20% or more of the Company's Common Stock (the "Shares Acquisition Date").

EXPIRATION OF THE RIGHTS:

The Rights expire on the earliest of (a) October 13, 2016, (b) exchange or redemption of the Rights as described above, or (c) consummation of a merger or consolidation resulting in expiration of the Rights as described above.

AMENDMENT OF TERMS OF RIGHTS:

The terms of the Rights and the Rights Agreement may be amended in any respect without the consent of the Rights holders on or prior to the Distribution Date; thereafter, the terms of the Rights and the Rights Agreement may be amended without the consent of the Rights holders in order to cure any ambiguities or to make changes which do not adversely affect the interests of Rights holders (other than the Acquiring Person).

VOTING RIGHTS:

Rights will not have any voting rights.

ANTI-DILUTION PROVISIONS:

Rights will have the benefit of certain customary anti-dilution provisions.

The Rights distribution should not be taxable for federal income tax purposes. However, following an event which renders the Rights exercisable or upon redemption of the Rights, stockholders may recognize taxable income.

The foregoing is a summary of certain principal terms of the Stockholder Rights Plan only and is qualified in its entirety by reference to the detailed terms of the 2006 Preferred Shares Rights Agreement dated as of October 13, 2006, as amended from time to time, between the Company and the Rights Agent. Further details of the Rights are contained in a letter that will be mailed to all the Company's stockholders.


EXHIBIT 99.1

Contact: Paul V. Maier
Senior Vice President
and Chief Financial Officer
858-550-7573

LIGAND RENEWS STOCKHOLDER RIGHTS PLAN
TRIGGER SET AT 20%

SAN DIEGO, CA -- OCTOBER 16, 2006 -- Ligand Pharmaceuticals Incorporated (NASDAQ: LGND) ("Ligand") today announced that the Board of Directors of Ligand has renewed the stockholder rights plan, which was originally adopted and has been in place since September 1996, and which expired on September 13, 2006, through the adoption of a new 2006 Stockholder Rights Plan (the "2006 Rights Plan"). The 2006 Rights Plan is intended to enable all Ligand stockholders to realize the long-term value of their investment in Ligand. The 2006 Rights Plan will not prevent a takeover, but should encourage anyone seeking to acquire Ligand to negotiate with the Board of Directors prior to attempting a takeover. The 2006 Rights Plan has substantially the same terms as the expired rights plan other than an increase in the threshold percentage of beneficial ownership that will trigger a distribution of the rights under the 2006 Rights Plan to 20% of outstanding shares, from the 10% level previously in effect. The 2006 Rights Plan will expire in 2016. Pursuant to the 2006 Rights Plan, Ligand's Board of Directors declared a dividend distribution of one Preferred Share Purchase Right (a "Right") on each outstanding share of Ligand's common stock. Subject to limited exceptions, the Rights will be exercisable if a person or group acquires 20% or more of Ligand's outstanding common stock or announces a tender offer for 20% or more of the common stock. Ligand's Board of Directors may approve redemption of the Rights in whole, but not in part, at a price of $0.01 per Right.
The Rights will become exercisable to purchase 1/1000th of a share of Ligand's Series A Participating Preferred Stock, at an exercise price of $100.00 per Right, when any person or group announces the intent to acquire or acquires 20% or more of Ligand's Common Stock. In that event, the Rights permit Ligand stockholders, other than the acquiring person, to purchase Ligand Common Stock having a market value of twice the exercise price of the Rights, in lieu of the Preferred Stock. In addition, in the event of certain business combinations, the Rights permit the purchase of the Common Stock of an acquiring person at a 50% discount. Rights held by the acquiring person will become null and void in each case.
The Rights are not being distributed in response to any specific effort to acquire control of Ligand. The Rights are designed to assure that all Ligand stockholders receive fair and equal treatment in the event of any proposed takeover of Ligand and to guard against partial tender offers, open market accumulations and other potentially abusive tactics to gain control of Ligand, while not foreclosing a fair acquisition bid for Ligand.
The dividend distribution to establish the 2006 Rights Plan will be payable on October 31, 2006 to stockholders of record on that date. The Rights distribution is not taxable to stockholders.

ABOUT LIGAND

Ligand discovers, develops and markets new drugs that address critical unmet medical needs of patients in the areas of cancer, pain, skin diseases, men's and women's hormone-related diseases, osteoporosis, metabolic

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disorders, and cardiovascular and inflammatory diseases. Ligand's proprietary drug discovery and development programs are based on its leadership position in gene transcription technology, primarily related to intracellular receptors. For more information, go to www.ligand.com.

CAUTION REGARDING FORWARD-LOOKING STATEMENTS

This news release contains certain forward-looking statements by Ligand that involve risks and uncertainties and reflect Ligand's judgment as of the date of this release. These statements include those related to the benefits of the 2006 Rights Plan and the ability of the 2006 Rights Plan to maximize stockholder value in the event of a takeover of Ligand. Actual events or results may differ materially from those set forth in this release due to the risks and uncertainties inherent in Ligand's business, including, without limitation, discouragement or prevention of a change in control of Ligand. Additional information concerning these and other risk factors affecting Ligand's business can be found in prior press releases as well as in Ligand's public periodic filings with the Securities and Exchange Commission, available via the company's internet site at www.ligand.com. Ligand disclaims any intent or obligation to update these forward-looking statements beyond the date of this release. This caution is made under the safe harbor provisions of the Private Securities Litigation Reform Act of 1995.

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