THRESHOLD PHARMACEUTICALS, INC. and MELLON INVESTOR SERVICES LLC Rights Agent PREFERRED SHARES RIGHTS AGREEMENT Dated as of August 8, 2006

EXHIBIT 4.5

THRESHOLD PHARMACEUTICALS, INC.

and

MELLON INVESTOR SERVICES LLC

Rights Agent

Dated as of August 8, 2006

TABLE OF CONTENTS


		Page
1.	Certain Definitions	1
2.	Appointment of Rights Agent	3
3.	Issuance of Rights Certificates	3
4.	Form of Rights Certificates	7
5.	Countersignature and Registration	8
6.	Transfer, Split Up, Combination and Exchange of Rights Certificates; Mutilated, Destroyed, Lost or Stolen Rights Certificates	9
7.	Exercise of Rights; Purchase Price; Expiration Date of Rights	9
8.	Cancellation and Destruction of Rights Certificates	11
9.	Reservation and Availability of Preferred Shares	11
10.	Preferred Shares Record Date	13
11.	Adjustment of Purchase Price, Number of Shares or Number of Rights	13
12.	Certificate of Adjusted Purchase Price or Number of Shares	21
13.	Consolidation, Merger or Sale or Transfer of Assets or Earning Power	21
14.	Fractional Rights and Fractional Shares	24
15.	Rights of Action	24
16.	Agreement of Rights Holders	25
17.	Rights Certificate Holder Not Deemed a ▇▇▇▇▇▇▇▇▇▇▇	▇▇
▇▇.	Concerning the Rights Agent	26
19.	Merger or Consolidation or Change of Name of Rights Agent	26
20.	Duties of Rights Agent	27
21.	Change of Rights Agent	29
22.	Issuance of New Rights Certificates	30
23.	Redemption	30
24.	Exchange	31
25.	Notice of Certain Events	33
26.	Notices	33
27.	Supplements and Amendments	34
28.	Successors	34
29.	Determinations and Actions by the Board of Directors, etc	34
30.	Benefits of this Agreement	35
31.	Severability	35
32.	Governing Law	35
33.	Counterparts	35
34.	Descriptive Headings	35

EXHIBITS

Exhibit A Form of Certificate of Designations
Exhibit B Form of Rights Certificate
Exhibit C Summary of Rights

THRESHOLD PHARMACEUTICALS, INC.

PREFERRED SHARES RIGHTS AGREEMENT

This Preferred Shared Rights Agreement, dated as of August 8, 2006, is made between Threshold Pharmaceuticals, Inc., a Delaware corporation (the “Company”), and Mellon Investor Services LLC, a New Jersey limited liability company (the “Rights Agent”).

RECITALS

On August 8, 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 August 23, 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 form of Certificate of Designations attached to this Agreement as Exhibit A, 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.

AGREEMENT

The parties agree as follows:

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 15% or more of the Common Shares then outstanding, but shall not include the Company, any Subsidiary of the Company or 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 15% or more of the Common Shares of the Company then outstanding; provided, however, that if a Person shall become the Beneficial Owner of 15% 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, (other than pursuant to a dividend or distribution paid or made by the Company on the outstanding Common Shares in Common Shares or pursuant to a split or subdivision of the outstanding Common Shares), then such Person shall be deemed to be an

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Acquiring Person unless upon becoming the Beneficial Owner of such additional Common Shares of the Company such Person does not beneficially own 15% or more of the Common Shares of the Company then outstanding. Notwithstanding the foregoing, (i) 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 the foregoing provisions of this Section 1(a) has become such inadvertently (including, without limitation, because (A) such Person was unaware that it beneficially owned a percentage of the Common Shares that would otherwise cause such Person to be an “Acquiring Person,” as defined pursuant to the foregoing provisions of this Section 1(a) or (B) such Person was aware of the extent of the Common Shares it beneficially owned but had no actual knowledge of the consequences of such beneficial ownership under this Agreement) and without any intention of changing of influencing control of the Company, and if such Person divested or divests as promptly as practicable a sufficient number of Common Shares to that such Person would no longer be an “Acquiring Person,” as defined pursuant to the foregoing provisions of this paragraph (a), then such Person shall not be deemed to be or to have become an “Acquiring Person” for any purposes of this Agreement; and (ii) if, as of the date hereof, any Person is the Beneficial Owner of 15% or more of the Common Shares outstanding, such Person shall not be or become an “Acquiring Person,” as defined pursuant to the foregoing provisions of this Section 1(a), unless and until such time as such Person shall become the Beneficial Owner of additional Common Shares (other than pursuant to a dividend or distribution paid or made by the Company on the outstanding Common Shares in Common Shares or pursuant to a split or subdivision of the outstanding Common Shares), unless, upon becoming the Beneficial Owner of such additional Common Shares, such Person is not then the Beneficial Owner of 15% or more of the Common Shares then outstanding.

(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.

(i) which such Person or any of such Person’s Affiliates or Associates, including a group of which such Person or any of such Person’s Affiliates or Associates is a member (within the meaning of Section 13(d)(3) of the Exchange Act of 1934), 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, including a group of which such Person or any of such Person’s Affiliates or Associates is a member (within the meaning of Section 13(d)(3) of the Exchange Act of 1934), 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, 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), 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 l(c)(ii)(A) to be the Beneficial Owner of, or

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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 prior to a Triggering Event; 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 l(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 l(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 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) “Board of Directors” shall mean the Board of Directors of the Company then in office.

(e) “Business Day” shall mean any day other than a Saturday, Sunday or a day on which banking institutions in New York or New Jersey are authorized or obligated by law or executive order to close.

(f) “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.

(g) “Common Shares” when used with reference to the Company shall mean the shares of Common Stock of the Company, $0.001 par value. “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.

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(h) “Distribution Date” shall mean the earlier of (i) the Close of Business on the tenth day 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 a majority of the 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 15% or more of the shares of Common Stock then outstanding.

(i) “Equivalent Shares” shall mean Preferred Shares and any other class or series of capital stock of the Company that 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.

(j) “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 of this Agreement or (iv) the consummation of a transaction contemplated by Section 13(d) of this Agreement.

(k) “Final Expiration Date” shall mean August 8, 2016.

(l) “Person” shall mean any individual, firm, corporation, limited liability company 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) of this Agreement.

(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 of this Agreement.

(q) “Redemption Price” shall have the meaning set forth in Section 23(a) of this Agreement.

(r) “Right” shall have the meaning set forth in the recitals at the beginning of this Agreement.

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

(t) “Section 13 Event” shall mean any event described in clause (i), (ii) or (iii) of Section 13(a) of this Agreement.

(u) “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) of 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 l(a)(ii) of this Agreement, then no Shares Acquisition Date shall be deemed to have occurred.

(v) “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.

(w) “Total Exercise Price” shall have the meaning set forth in Section 4(a) of this Agreement.

(x) “Trading Day” shall have the meaning set forth in Section 11(d) of this Agreement.

(y) 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.

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 or omissions of any such co-Rights Agent.

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) of this Agreement) 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

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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 if provided with all 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 B to this Agreement (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) of this Agreement, then at the time of distribution of the Rights Certificates, the Company shall make the necessary and appropriate rounding adjustments (in accordance with Section 14(a) of this Agreement) 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 and, if such notification is given orally, the Company shall confirm the same in writing on or prior to the Close of Business on the Business Day next following. 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 (or cause to be sent) a copy of a Summary of Rights in substantially the form of Exhibit C to this Agreement (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 of this Agreement, after the Distribution Date. Certificates representing such Common Shares shall also be deemed to be certificates for Rights, and shall bear a legend in substantially the following form:

This certificate also evidences and entitles the holder hereof to certain rights as set forth in a Preferred Shares Rights Agreement between Threshold Pharmaceuticals, Inc. and Mellon Investor Services LLC as the Rights Agent, dated as of August 8, 2006 (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 Threshold Pharmaceuticals, Inc. 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. Threshold Pharmaceuticals, Inc. will mail to the holder of this certificate a copy of the Rights Agreement without

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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 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.

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 B to this Agreement 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 or 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 of this Agreement, 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), shall show the date of countersignature by the Rights Agent, 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 of this Agreement 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 (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

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Person with whom such Acquiring Person has any continuing agreement, arrangement or understanding regarding the transferred Rights or (B) a transfer that the Board of Directors of the Company has determined is part of a plan, arrangement or understanding that has as a primary purpose or effect avoidance of Section 7(e) of this Agreement (a “Prior Transferee” or (iv) any subsequent transferee received transferred Rights from a Post Transferee or a Prior Transferee, shall become null and void , and any Rights Certificate issued pursuant to Section 6 or Section 11 of this Agreement upon transfer, exchange, replacement or adjustment of any other Rights Certificate referred to in this sentence, shall contain (to the extent the Rights Agent has written notice thereof and to the extent feasible) a legend in substantially the following form:

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 are null and void in the circumstances specified in Section 7(e) of the Rights Agreement.

In the event that the Rights become exercisable, the Rights Agent and the Company will agree upon a procedure for determining which Rights will be so legended.

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 an authorized signatory of 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 Rights Agreement any such person was not such an officer.

(b) Following the Distribution Date and receipt by the Rights Agent of (i) written notice of the Distribution Date pursuant to Section 3(a) hereof and (ii) a stockholder list and all relevant information requested by the Rights Agent pursuant to Section 3(a) hereof, 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.

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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 of this Agreement, 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. The Rights Certificates are transferable only on the registry books of the Rights Agent. 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 properly 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 of this Agreement, 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 duty or obligation under this Section 6 unless and until it is satisfied that provision for the payment of all such taxes and/or governmental charges has been made.

(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 satisfactory to them, and, at the Company’s or the Rights Agent’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.

7. Exercise of Rights; Purchase Price; Expiration Date of Rights.

(a) Subject to Sections 7(e), 23(b) or 24 of this Agreement, 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.

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(b) The Purchase Price for each one-thousandth of a Preferred Share issuable pursuant to the exercise of a Right shall initially be $25.00, shall be subject to adjustment from time to time as provided in Sections 11 and 13 of this Agreement 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 tax or charge required to be paid by the holder of such Rights Certificate in accordance with Section 9 of this Agreement 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) of this Agreement, 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 total number of one-thousandths of a Preferred Share issuable upon exercise of the Rights hereunder with a depository agent, requisition from the depository agent of depository 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 depository agent) and the Company hereby directs the depository 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 of this Agreement, (iii) after receipt of such certificates or depository 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) of this Agreement) may be made in cash or by certified check or cashier’s check 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) of this Agreement, 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 necessary to comply with this agreement.

(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 of this Agreement.

(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

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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 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 promptly notify the Rights Agent in writing when this Section 7(e) applies and shall use all reasonable efforts to ensure that the provisions of this Section 7(e) and Section 4(b) of this Agreement are complied with, but neither the Company nor the Rights Agent shall have any 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.

(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) duly and properly 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 or the Rights Agent shall reasonably request.

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.

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

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preferred stock not reserved for another purpose (and, following the occurrence of a Triggering Event, out of its authorized and unissued shares of Common Shares and/or other securities), the number of Preferred Shares (and, following the occurrence of the Triggering Event, Common Shares 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 a national securities 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 the Board of Directors of the Company determines 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 Sections 11(a)(ii) or 11(a)(iii) of this Agreement, 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 (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 promptly notify the Rights Agent thereof in writing, that the exercisability of the Rights has been temporarily suspended, as well as a public announcement and prompt written 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

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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 tax or charge 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 depository 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 depository receipts for Preferred Shares upon the exercise of any Rights until any such tax or charge shall have been paid (any such tax or charge 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 or charge is due.

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 taxes or charges) 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 exercise any preemptive rights, and shall not be entitled to receive any notice of any proceedings of the Company, except as provided herein.

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) of this Agreement: (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 dividend, subdivision, combination or reclassification of the Common Shares outstanding immediately following such dividend, subdivision, combination or reclassification and the denominator of which shall be the total number of Common Shares outstanding immediately

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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 adjusted to be the kind of shares of such other capital stock issued in such reclassification, rather than Preferred Shares. If an event occurs which would require an adjustment under both this Section 11(a)(i) and Section 11(a)(ii) of this Agreement, 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) of this Agreement.

(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) of this Agreement, 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 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) of this Agreement) 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) of this Agreement, 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 Amended and Restated 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

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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 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 based upon the advice of a nationally recognized investment banking firm selected by the Board of Directors; 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 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 Section 11(a)(iii), the Company (x) shall provide, subject to Section 7(e) of this Agreement, 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 (with prompt written notice thereof to the Rights Agent), as well as a public announcement at such time as the suspension is no longer in effect (with prompt written notice thereof to the Rights Agent). 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) of this Agreement) 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

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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, whose determination shall be described in a written 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 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) of this Agreement) 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, whose determination shall be described in a written 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) of this Agreement) 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.

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(d) For the purpose of any computation hereunder, other than computations made pursuant to Section 11(a)(iii) of this Agreement, 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 but not including such date, and for purposes of computations made pursuant to Section 11(a)(iii) of this Agreement, 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 but not including 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 NASDAQ Stock Market LLC (“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. 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 shall be used. The term “Trading Day” shall mean a day on which the principal national securities exchange on which the Security is listed or admitted to trading is open for the transaction of business or, if the Security is not listed or admitted to trading on any national securities exchange, a Business Day. 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, 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

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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 Sections 11(a) or 13(a) of this Agreement, 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), (1) 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 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 ten-thousandth) obtained by dividing the Purchase Price in effect immediately prior to adjustment of the Purchase Price by the Purchase Price in effect immediately after adjustment of the Purchase Price. The Company shall promptly notify the Rights Agent in writing and 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,

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cause to be distributed to holders of record of Rights Certificates on such record date Rights Certificates evidencing, subject to Section 14 of this Agreement, 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.

(1) 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 promptly notify the Rights Agent in writing of such election and deliver to such holder a due ▇▇▇▇ 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.

(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.

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(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) of this Agreement 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 of this Agreement, 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) of this Agreement: (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 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.

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12. Certificate of Adjusted Purchase Price or Number of Shares. Whenever an adjustment is made or any event affecting the Rights or their exercisability (including without limitation an event which causes Rights to become null and void) occurs as provided in Sections 11 and 13 hereof, the Company shall promptly (a) prepare a certificate setting forth such adjustment or describing such event, and a brief, reasonably detailed statement of the facts, computations and methodology 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) if such adjustment occurs following the Distribution Date, mail a brief summary thereof to each holder of a Rights Certificate in accordance with Section 26 of this Agreement. 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 or statement contained therein and shall have no duty or liability with respect to and shall not be deemed to have knowledge of any such adjustment or any such event unless and until it shall have received such certificate.

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 that complies with Section 11(o) of this Agreement);

(ii) any Person (other than a Subsidiary of the Company in a transaction that complies with Section 11(o) of this Agreement) 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) of this Agreement),

then, and in each such case, proper provision shall be made so that

(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

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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) of this Agreement) 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 of this Agreement 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 to permit the exercise of Rights in full for such Common Shares) in connection with the consummation of any such transaction as may be necessary to assure that the provisions of this Agreement 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 referred to therein or such 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 Section 13(a)(iii), “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) of this Agreement, of such Common Shares of such Principal Party. If, for any reason, the foregoing formulation cannot be applied to

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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) of this Agreement, 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.

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14. Fractional Rights and Fractional Shares.

(a) The Company shall not be required to issue fractions of Rights or to distribute Rights Certificates that 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) of this Agreement.

(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) of this Agreement) 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.

(d) Whenever a payment for fractional Rights or fractional shares is to be made by the Rights Agent, the Company shall (i) promptly prepare and deliver to the Rights Agent a certificate setting forth in reasonable detail the facts related to such payment and the prices and/or formulas utilized in calculating such payments, and (ii) provide sufficient monies to the Rights Agent in the form of fully collected funds to make such payments. The Rights Agent shall be fully protected in relying upon such a certificate and shall have no duty with respect to, and shall not be deemed to have knowledge of any payment for fractional Rights or fractional shares under any Section of this Agreement relating to the payment of fractional Rights or fractional shares unless and until the Rights Agent shall have received such a certificate and sufficient monies.

15. Rights of Action. (a) All rights of action in respect of this Agreement, excepting the rights of action given to the Rights Agent herein, 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

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the holders of Rights would not have an adequate remedy at law for any breach of this Agreement by the Company and will be entitled to specific performance of the obligations under, and injunctive relief against actual or threatened violations by the company of, the obligations of any Person subject to this Agreement.

(b) Notwithstanding anything in this Agreement to the contrary, neither the Company nor the Rights Agent shall have any liability to any holder of a Right or other Person as a result of its inability to perform any of its obligations under this Agreement by reason of any preliminary or permanent injunction or other order, decree, judgment or ruling (whether interlocutory or final) issued by a court of competent jurisdiction or by a governmental, regulatory or administrative agency or commission, or any statute, rule, regulation or executive order promulgated or enacted by any governmental authority, prohibiting or otherwise restraining performance of such obligation; provided, however, that the Company shall use its best efforts to have any such order, decree, judgment or ruling lifted or otherwise overturned as soon as reasonably practicable.

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;

(b) after the Distribution Date, the Rights Certificates are transferable only on the registry books of the Rights Agent if surrendered at the 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) of this Agreement, 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.

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 of this Agreement), 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 of this Agreement.

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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 preparation, administration, delivery, execution and amendment 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, damage, judgment, fine, penalty, claim, demand, settlement, cost or expense (including, without limitation, the reasonable fees and expenses of legal counsel), incurred without gross negligence, bad faith or willful misconduct on the part of the Rights Agent (which gross negligence, bad faith or willful misconduct on the part of the Rights Agent, if in dispute, shall have been determined by a final non-appealable order, judgment, decree or ruling of a court of competent jurisdiction), for any action taken, suffered or omitted by the Rights Agent in connection with the acceptance and administration of this Agreement or in the exercise or performance of its duties hereunder. The costs and expenses incurred in enforcing this right of indemnification shall be paid by the Company. The indemnity provided herein shall survive the termination of this Agreement and the termination and the expiration of the Rights.

(b) The Rights Agent shall be authorized and protected and shall incur no liability for, or in respect of any action taken, suffered or omitted by it in connection with, the acceptance and administration of this Agreement or in the exercise or performance of its duties hereunder in reliance upon any Rights Certificate or certificate for the 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. The Rights Agent shall not be deemed to have knowledge of any event of which it was supposed to receive notice thereof hereunder, and the Rights Agent shall be fully protected and shall incur no liability for failing to take any action in connection therewith unless and until it has received such notice.

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 shareholder services 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 to this Agreement; provided, however, that such Person would be eligible for appointment as a successor Rights Agent under the provisions of Section 21 of this Agreement. In case at the time such successor Rights Agent shall succeed to the agency created by this Agreement, any of the

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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.

20. Duties of Rights Agent. The Rights Agent undertakes to perform only the duties and obligations, and only the duties and obligations, expressly imposed by this Agreement (and no implied duties or obligations) 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 or an employee of the Rights Agent), and the opinion or advice of such counsel shall be full and complete authorization and protection to the Rights Agent and the Rights Agent shall incur no liability for or in respect of any action taken, suffered or omitted by it in accordance with such opinion or advice.

(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 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, suffering or omitting 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 of Directors of the Company, the Chief Executive Officer, the President, any Vice President, the Chief Operating Officer, 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 and complete authorization and protection to the Rights Agent, and the Rights Agent shall incur no liability for or in respect of any action taken, suffered or omitted 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 (which gross negligence, bad faith or willful misconduct on the part of the Rights Agent, if in dispute, shall have been determined by a final non-appealable order, judgment, decree or ruling of a court of competent jurisdiction). Anything in this Agreement to the contrary notwithstanding, in no event shall the Rights Agent be liable for special, punitive, indirect, incidental or consequential loss or

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damage of any kind whatsoever (including, but not limited, lost profits), even if the Rights Agent has been advised of the possibility of such loss or damage. Any liability of the Rights Agent under this Agreement shall be limited to the amount of annual fees paid by the Company to the Rights Agent.

(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 have any liability for, nor shall it be under any responsibility in respect of the validity hereof 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 (including the Rights becoming null and void hereunder) or any adjustment in the terms of the Rights (including the manner, method or amount thereof) provided for in Section 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 actual notice that such change or adjustment is required); 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 of Directors of the Company, the Chief Executive Officer, the Chief Operating 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 such advice or instructions shall be full authorization and protection to the Rights Agent and the Rights Agent shall incur no liability for or in respect of any action taken, suffered or omitted by it in accordance with instructions of any such officer or for any delay in acting while waiting for such instructions. Any application by the Rights Agent for written instructions from the Company may, at the option of the Rights Agent, set forth in writing any action proposed to be taken, suffered or omitted by the Rights Agent under this Agreement and the date on and/or after which such action shall be taken or suffered or such omission shall be effective. The Rights Agent shall not be liable for any action taken or suffered 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

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officer shall have consented in writing to an earlier date) unless, prior to taking suffering or omitting 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, suffered or omitted.

(h) The Rights Agent and any stockholder, director, member, Affiliate, 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 the Rights Agent were not Rights Agent under this Agreement. Nothing herein shall preclude the Rights Agent or any such stockholder, director, member, Affiliate, officer or employee from acting in any other capacity for the Company or for any other Person.

(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 (through its directors, officers and employees) 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 or any other Person resulting from any such act, default, neglect or misconduct, absent gross negligence or willful misconduct (which gross negligence, bad faith or willful misconduct on the part of the Rights Agent, if in dispute, shall have been determined by a final non-appealable order, judgment, decree or ruling of a court of competent jurisdiction) 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 the Rights Agent believes that repayment of such funds or adequate indemnification against such risk or liability is not assured 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.

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 known to the Rights Agent, 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 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

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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 either (a) 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 shareholder 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 or (b) an Affiliate of such Person. 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.

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 of the Company 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, issued by the Company and (b) may, in any other case, if deemed necessary or appropriate by the Board of Directors, 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.

23. Redemption.

(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 Final Expiration Date, redeem all but not less than all the then outstanding Rights at a redemption price of $0.01 per Right,

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appropriately adjusted to reflect any stock split, stock dividend or similar transaction occurring after the date of this Agreement (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) of this Agreement) at the time of redemption) or cash. Such redemption 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 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, such notice shall not affect 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 prompt written 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 of this Agreement, and other than in connection with the purchase of Common Shares prior to the Distribution Date.

24. Exchange.

(a) Subject to applicable laws, rules and regulations, and subject to subsection (c) below, the Company may, at its option, by majority vote of 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 null and void pursuant to the provisions of Section 7(e) of this Agreement) 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 of this Agreement (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.

(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

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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 (with prompt written notice thereof to the Rights Agent); 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 null and void pursuant to the provisions of Section 7(e) of this Agreement) 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 (with prompt written notice thereof to the Rights Agent).

(d) The Company shall not be required to issue fractions of Common Shares or to distribute certificates that 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) of this Agreement).

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(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 (with prompt written notice thereof to the Rights Agent); 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 the Rights Agent and 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.

25. Notice of Certain Events.

(a) In case the Company shall propose to effect or permit to occur any Section 13 Event, the Company shall give written notice thereof to the Rights Agent and to each holder of Rights in accordance with Section 26 of this Agreement at least twenty (20) days prior to occurrence of 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 the Rights Agent and each holder of a Rights Certificate, in accordance with Section 26 of this Agreement, a written 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 of this Agreement.

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) or by facsimile transmission as follows:

Threshold Pharmaceuticals, Inc.

▇▇▇▇ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇

▇▇▇▇▇▇▇ ▇▇▇▇, ▇▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇

Attention: Chief Executive Officer

Facsimile No:

Subject to the provisions of Section 21 of this Agreement, 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

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prepaid, addressed (until another address is filed in writing with the Company) or by facsimile transmission as follows:

Mellon Investor Services LLC

▇▇▇ ▇▇▇▇▇▇▇▇▇▇ ▇▇▇▇.

▇▇▇▇▇▇ ▇▇▇▇, ▇▇ ▇▇▇▇▇

Attention: General Counsel

Facsimile No: (▇▇▇) ▇▇▇-▇▇▇▇

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.

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, subject to the other terms and conditions of this agreement, 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) 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, and provided that such supplement or amendment does not change or increase the Rights Agent’s rights, duties, liabilities or obligations, 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.

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.

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 shall have the exclusive power and authority to

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administer this Agreement and to exercise all rights and powers specifically granted to the Board of Directors, 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 and calculations deemed necessary or advisable for the administration of this Agreement (including a determination to redeem or not redeem the Rights or to amend the Agreement). All such actions, calculations, interpretations and determinations (including, for purposes of clause (y) below, all omissions with respect to the foregoing) which are done or made by the Board of Directors 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. The Rights Agent shall always be entitled to assume that the Board of Directors of the Company acted in good faith and the Rights Agent shall be fully protected and shall incur no liability in reliance thereon.

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).

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 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 of this Agreement 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.

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; provided, however, that all provisions regarding the rights duties, liabilities and obligations of the Rights Agent shall be governed by and construed in accordance with the laws of the State of New York applicable to contracts made and to be performed entirely within such state.

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.

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 of this Agreement.

* * *

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The parties have caused this Agreement to be duly executed as of the date first written above.


THRESHOLD PHARMACEUTICALS, INC.

By:		/s/ ▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇
Name:		▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇
Title:		Chief Executive Officer

MELLON INVESTORS SERVICES LLC

By:		/s/ ▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇
Name:		▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇
Title:		Director, Business Development

[Signature Page to Preferred Shares Rights Agreement]

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EXHIBIT A

FORM OF CERTIFICATE OF DESIGNATIONS

EXHIBIT A

CERTIFICATE OF DESIGNATIONS

OF RIGHTS, POWERS AND PREFERENCES OF

SERIES A PARTICIPATING PREFERRED STOCK

THRESHOLD PHARMACEUTICALS, INC.

Pursuant to Section 151(g) and Section 103 of the General Corporation Law of the State of Delaware, I, ▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇, the Chief Executive Officer, of Threshold Pharmaceuticals, Inc. (the “Corporation”), a corporation organized and existing under the General Corporation Law of the State of Delaware hereby certify:

That pursuant to the authority conferred upon the Board of Directors by the Amended and Restated Certificate of Incorporation of the Corporation, the Board of Directors, on August 8, 2006 adopted the following resolution creating a series of shares of Preferred Stock designated as Series A Participating Preferred Stock:

“RESOLVED: that pursuant to the authority vested in the Board of Directors of the Corporation by the Amended and Restated Certificate of Incorporation (the “Restated Certificate”), the Board of Directors does hereby provide for the issue of a series of Preferred Shares, $0.001 par value, of the Corporation, to be designated “Series A Participating Preferred Stock”, initially consisting of Two Hundred Thousand (200,000) shares and to the extent that the designations, powers, preferences and relative and other special rights and the qualifications, limitations and restrictions of the Series A Participating Preferred Stock are not stated and expressed in the Restated Certificate, does hereby fix and herein state and express such designations, powers, preferences and relative and other special rights and the qualifications, limitations and restrictions thereof, as follows (all terms used herein which are defined in the Restated Certificate shall be deemed to have the meanings provided therein):

1. Designation and Amount. The shares of such series shall be designated as “Series A Participating Preferred Stock”, par value $0.001 per share, and the number of shares constituting such series shall be Two Hundred Thousand (200,000). Such number of shares may be increased or decreased by resolution of the Board of Directors; provided, however, that no decrease shall reduce the number of shares of Series A Participating Preferred Stock to a number of shares less than the number of shares then outstanding plus the number of shares reserved for issuance upon the exercise of outstanding options, rights or warrants or upon the conversion of any outstanding securities issued by the Corporation convertible into Series A Participating Preferred Stock.

2. Dividends and Distributions.

(A) Subject to the prior and superior right of the holders of any shares of any series of Preferred Stock ranking prior and superior to the shares of Series A Participating

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Preferred Stock with respect to dividends, the holders of shares of Series A Participating Preferred Stock shall be entitled to receive when, as and if declared by the Board of Directors out of funds legally available for the purpose, quarterly dividends payable in cash on the last day of March, June , September and December in each year (each such date being referred to herein as a “Quarterly Dividend Payment Date”), commencing on the first Quarterly Dividend Payment Date after the first issuance of a share or fraction of a share of Series A Participating Preferred Stock, in an amount per share (rounded to the nearest cent) equal to, subject to the provision for adjustment hereinafter set forth, 1,000 times the aggregate per share amount of all cash dividends, and 1,000 times the aggregate per share amount (payable in kind) of all non-cash dividends or other distributions other than a dividend payable in shares of Common Stock or a subdivision of the outstanding shares of Common Stock (by reclassification or otherwise), declared on the Common Stock of the Corporation (the “Common Stock”) since the immediately preceding Quarterly Dividend Payment Date, or, with respect to the first Quarterly Dividend Payment Date, since the first issuance of any share or fraction of a share of Series A Participating Preferred Stock. In the event the Corporation shall at any time after August 8, 2006 (the “Rights Declaration Date”) (i) declare any dividend on Common Stock payable in shares of Common Stock, (ii) subdivide the outstanding Common Stock, or (iii) combine or consolidate the outstanding Common Stock into a smaller number of shares, then in each such case the amount to which holders of shares of Series A Participating Preferred Stock were entitled immediately prior to such event under the preceding sentence shall be adjusted by multiplying such amount by a fraction, the numerator of which is the number of shares of Common Stock outstanding immediately after such event and the denominator of which is the number of shares of Common Stock that were outstanding immediately prior to such event.

(B) The Corporation shall declare a dividend or distribution on the Series A Participating Preferred Stock as provided in paragraph (A) above immediately after it declares a dividend or distribution on the Common Stock (other than a dividend payable in shares of Common Stock).

(C) Dividends shall begin to accrue and be cumulative on outstanding shares of Series A Participating Preferred Stock from the Quarterly Dividend Payment Date next preceding the date of issue of such shares of Series A Participating Preferred Stock, unless the date of issue of such shares is prior to the record date for the first Quarterly Dividend Payment Date, in which case dividends on such shares shall begin to accrue from the date of issue of such shares, or unless the date of issue is a Quarterly Dividend Payment Date or is a date after the record date for the determination of holders of shares of Series A Participating Preferred Stock entitled to receive a quarterly dividend and before such Quarterly Dividend Payment Date, in either of which events such dividends shall begin to accrue and be cumulative from such Quarterly Dividend Payment Date. Accrued but unpaid dividends shall not bear interest. Dividends paid on the shares of Series A Participating Preferred Stock in an amount less than the total amount of such dividends at the time accrued and payable on such shares shall be allocated pro rata on a share-by-share basis among all such shares at the time outstanding. The Board of Directors may fix a record date for the determination of holders of shares of Series A Participating Preferred Stock entitled to receive payment of a dividend or distribution declared thereon, which record date shall be no more than 60 days prior to the date fixed for the payment thereof.

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3. Voting Rights. The holders of shares of Series A Participating Preferred Stock shall have the following voting rights:

(A) Subject to the provision for adjustment hereinafter set forth, each share of Series A Participating Preferred Stock shall entitle the holder thereof to 1,000 votes on all matters submitted to a vote of the stockholders of the Corporation. In the event the Corporation shall at any time after the Rights Declaration Date (i) declare or pay any dividend on Common Stock payable in shares of Common Stock, (ii) subdivide the outstanding Common Stock, or (iii) combine the outstanding Common Stock into a smaller number of shares, then in each such case the number of votes per share to which holders of shares of Series A Participating Preferred Stock were entitled immediately prior to such event shall be adjusted by multiplying such number by a fraction, the numerator of which is the number of shares of Common Stock outstanding immediately after such event and the denominator of which is the number of shares of Common Stock that were outstanding immediately prior to such event.

(B) Except as otherwise provided herein, in the Restated Certificate, or by law, the holders of shares of Series A Participating Preferred Stock and the holders of shares of Common Stock, and any other capital stock of the Corporation having general voting rights, shall vote together as one class on all matters submitted to a vote of stockholders of the Corporation.

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

4. Certain Restrictions.

(A) The Corporation shall not declare any dividend on, make any distribution on, or redeem or purchase or otherwise acquire for consideration any shares of Common Stock after the first issuance of a share or fraction of a share of Series A Participating Preferred Stock unless concurrently therewith it shall declare a dividend on the Series A Participating Preferred Stock as required by Section 2 hereof.

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

(i) declare or pay dividends on, make any other distributions on, or redeem or purchase or otherwise acquire for consideration any shares of stock ranking junior (either as to dividends or upon liquidation, dissolution or winding up) to the Series A Participating Preferred Stock;

(ii) declare or pay dividends on, make any other distributions on any shares of stock ranking on a parity (either as to dividends or upon liquidation, dissolution or

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winding up) with Series A Participating Preferred Stock, except dividends paid ratably on the Series A Participating Preferred Stock and all such parity stock on which dividends are payable or in arrears in proportion to the total amounts to which the holders of all such shares are then entitled;

(iii) redeem or purchase or otherwise acquire for consideration shares of any stock ranking on a parity (either as to dividends or upon liquidation, dissolution or winding up) with the Series A Participating Preferred Stock, provided that the Corporation may at any time redeem, purchase or otherwise acquire shares of any such parity stock in exchange for shares of any stock of the Corporation ranking junior (either as to dividends or upon dissolution, liquidation or winding up) to the Series A Participating Preferred Stock;

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

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

5. Reacquired Shares. Any shares of Series A Participating Preferred Stock purchased or otherwise acquired by the Corporation in any manner whatsoever shall be retired and canceled promptly after the acquisition thereof. All such shares shall upon their cancellation become authorized but unissued shares of Preferred Stock and may be reissued as part of a new series of Preferred Stock to be created by resolution or resolutions of the Board of Directors, subject to the conditions and restrictions on issuance set forth herein or in the Restated Certificate, or as otherwise required by law.

6. Liquidation, Dissolution or Winding Up.

(A) Upon any liquidation (voluntary or otherwise), dissolution or winding up of the Corporation, no distribution shall be made to the holders of shares of stock ranking junior (either as to dividends or upon liquidation, dissolution or winding up) to the Series A Participating Preferred Stock unless, prior thereto, the holders of shares of Series A Participating Preferred Stock shall have received an amount equal to accrued and unpaid dividends and distributions thereon, whether or not declared, to the date of such payment, plus an amount equal to the greater of (1) $1,000 per share, provided that in the event the Corporation does not have sufficient assets, after payment of its liabilities and distribution to holders of Preferred Stock ranking prior to the Series A Participating Preferred Stock, available to permit payment in full of the $1,000 per share amount, the amount required to be paid under this Section 6(A)(1) shall, subject to Section 6(B) hereof, equal the value of the amount of available assets divided by the

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number of outstanding shares of Series A Participating Preferred Stock or (2) subject to the provisions for adjustment hereinafter set forth, 1,000 times the aggregate per share amount to be distributed to the holders of Common Stock (the greater of (1) or (2), the “Series A Liquidation Preference”). In the event the Corporation shall at any time after the Rights Declaration Date (i) declare any dividend on Common Stock payable in shares of Common Stock, (ii) subdivide the outstanding Common Stock, or (iii) combine or consolidate the outstanding Common Stock into a smaller number of shares, then in each such case the amount to which holders of shares of Series A Participating Preferred Stock were entitled immediately prior to such event under clause (2) of the preceding sentence shall be adjusted by multiplying such amount by a fraction the numerator of which is the number of shares of Common Stock that were outstanding immediately after such event and the denominator of which is the number of shares of Common Stock that were outstanding immediately prior to such event.

(B) In the event, however, that there are not sufficient assets available to permit payment in full of the Series A Liquidation Preference and the liquidation preferences of all other series of Preferred Stock, if any, which rank on a parity with the Series A Participating Preferred Stock, then such remaining assets shall be distributed ratably to the holders of such parity shares in proportion to their respective liquidation preferences.

7. Consolidation, Merger, etc. In case the Corporation shall enter into any consolidation, merger, combination or other transaction in which the shares of Common Stock are exchanged for or changed into other stock or securities, cash and/or any other property, then in any such case the shares of Series A Participating Preferred Stock shall at the same time be similarly exchanged or changed in an amount per share (subject to the provision for adjustment hereinafter set forth) equal to 1,000 times the aggregate amount of stock, securities, cash and/or any other property (payable in kind), as the case may be, into which or for which each share of Common Stock is changed or exchanged. In the event the Corporation shall at any time after the Rights Declaration Date (i) declare any dividend on Common Stock payable in shares of Common Stock, (ii) subdivide the outstanding Common Stock, or (iii) combine or consolidate the outstanding Common Stock into a smaller number of shares, then in each such case the amount set forth in the preceding sentence with respect to the exchange or change of shares of Series A Participating Preferred Stock shall be adjusted by multiplying such amount by a fraction the numerator of which is the number of shares of Common Stock outstanding immediately after such event and the denominator of which is the number of shares of common Stock that were outstanding immediately prior to such event.

8. No Redemption. The shares of Series A Participating Preferred Stock shall not be redeemable.

9. Ranking. The Series A Participating Preferred Stock shall rank junior to all other series of the Corporation’s Preferred Stock as to the payment of dividends and the distribution of assets, unless the terms of any such series shall provide otherwise.

10. Amendment. The Certificate of Incorporation of the Corporation shall not be further amended in any manner, including by merger or consolidation, which would materially alter or change the powers, preference or special rights of the Series A Participating Preferred

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Stock so as to affect them adversely without the affirmative vote of the holders of a majority or more of the outstanding shares of Series A Participating Preferred Stock, voting together as a single class.

11. Fractional Shares. Series A Participating Preferred Stock may be issued in fractions of a share which shall entitle the holder, in proportion to such holder’s fractional shares, to exercise voting rights, receive dividends, participate in distributions and to have the benefit of all other rights of holders of Series A Participating Preferred Stock.”

Executed this 9th day of August, 2006.

▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇

Chief Executive Officer

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EXHIBIT B

FORM OF RIGHTS CERTIFICATE

EXHIBIT B

FORM OF RIGHTS CERTIFICATE


Certificate No. R-		Rights

NOT EXERCISABLE AFTER AUGUST 8, 2016, OR EARLIER IF TERMINATED BY THE COMPANY. 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.]*

RIGHTS CERTIFICATE

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 Preferred Shares Rights Agreement, dated as of August 8, 2006 (the “Rights Agreement”), between Threshold Pharmaceuticals, Inc., Delaware corporation (the “Company”), and the 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 August 8, 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 (1/1,000) of a fully paid non-assessable share of Series A Participating Preferred Stock (the “Preferred Shares”), of the Company, at a purchase price of $25.00 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 , , 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 Preferred Shares or other securities 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.

*	The portion of the legend in bracket shall be inserted only if applicable and shall replace the preceding sentence.

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 less than integral multiples of 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 an authorized signatory of the Rights Agent.

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


ATTEST:		Threshold Pharmaceuticals, Inc.

		By:
Secretary			Chief Executive Officer

Countersigned:

Mellon Investor Services LLC


as Rights Agent

By:
	Authorized Signatory

Date of countersignature: _________________________________

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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 Rights Certificate on the books of the within-named Company, with full power of substitution.

Dated: ,

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., a commercial bank or trust company having an office or correspondent in the United States or any other member of a medallion signature guarantee program approved by the Securities Transfer Association.

CERTIFICATE

The undersigned hereby certifies by checking the appropriate boxes that:

(1) 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);

(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: ,

Signature

Signature Guaranteed:

Form of Reverse Side of Rights Certificate — continued

FORM OF ELECTION TO PURCHASE

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

To:

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 be issued in the name of:

Please insert social security or other identifying number

______________________________________________________________________________________________________________________________

(Please print name and address)

______________________________________________________________________________________________________________________________

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

Please insert social security or other identifying number

______________________________________________________________________________________________________________________________

(Please print name and address)

______________________________________________________________________________________________________________________________

Dated:

Signature

Signature Guaranteed:

CERTIFICATE

The undersigned hereby certifies by checking the appropriate boxes that:

(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);

Dated:

Signature

Signature Guaranteed:

Form of Reverse Side of Rights Certificate — continued

NOTICE

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.

EXHIBIT C

SUMMARY OF RIGHTS

EXHIBIT C

THRESHOLD PHARMACEUTICALS, INC.

PREFERRED SHARES RIGHTS PLAN

Summary of Rights


Distribution and Transfer of Rights; Rights Certificate:		The Board of Directors has declared a dividend of one Right for each share of Common Stock of Threshold Pharmaceuticals, Inc. (the “Company”) 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, 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 following the tenth day (or such later date as may be determined by a majority of the Company’s Board of Directors) after a person or group (a) acquires beneficial ownership of 15% 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 15% or more of the Company’s Common Stock (the “Distribution Date”).

Preferred Stock Purchasable Upon Exercise of Rights:		After the Distribution Date, each Right will entitle the holder to purchase, for $25.00, 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 15% or more of the Company’s Common Stock (other than pursuant to a tender offer deemed fair by the Board of Directors (a “Permitted Offer”)), 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 (unless the transaction satisfies certain conditions and is consummated with a person who acquired shares pursuant to a Permitted Offer, in which case the Rights will expire).

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Exchange Provision:		At any time after an Acquiring Person obtains 15% or more of the Company’s Common Stock (other than pursuant to a Permitted Offer) 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.

Expiration of the Rights:		The Rights expire on the earliest of (a) ▇▇▇▇▇▇ ▇, ▇▇▇▇, (▇) exchange or redemption of the Rights as described above, or (c) consummation of a merger or consolidation or sale of assets 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.

Taxes:		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 Preferred Shares Rights Plan only and is qualified in its entirety by reference to the detailed terms of the Rights Agreement dated as of August 8, 2006, between the Company and the Rights Agent.

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THRESHOLD PHARMACEUTICALS, INC. and MELLON INVESTOR SERVICES LLC Rights Agent PREFERRED SHARES RIGHTS AGREEMENT Dated as of August 8, 2006

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