AMENDMENT NO. 1 TO RIGHTS AGREEMENT

Exhibit 4.1

AMENDMENT NO. 1 TO

RIGHTS AGREEMENT

This AMENDMENT NO. 1 to RIGHTS AGREEMENT, dated as of May 4, 2012 (this “Amendment”), amends that certain Rights Agreement, dated as of September 18, 2002, between Dendreon Corporation, a Delaware corporation (the “Company”), and Computershare Shareowner Services LLC (f/k/a Mellon Investor Services LLC), a New Jersey limited liability company, as Rights Agent (the “Rights Agent”).

RECITALS

WHEREAS, the Board of Directors of the Company authorized and declared a dividend of one preferred share purchase right (each, a “Right”) for each share of common stock, par value $.001 per share, of the Company, outstanding on October 2, 2002, and authorized the issuance of one Right with respect to each such share that has become outstanding since October 2, 2002, each Right representing the right to purchase one one-hundredth of a share of Series A Junior Participating Preferred Stock, par value $.001 per share, of the Company;

WHEREAS, the Company has generated substantial net operating loss carryforwards for United States federal income tax purposes, and such net operating loss carryforwards may potentially provide significant tax benefits to the Company;

WHEREAS, the Company desires to avoid an “ownership change” as contemplated by Section 382 of the Internal Revenue Code, as amended, and the Treasury Regulations promulgated thereunder, which could detrimentally impact the ability of the Company to realize tax benefits associated with the net operating loss carryforwards;

WHEREAS, pursuant to Section 27 of the Rights Agreement, the Company may from time to time supplement or amend the Rights Agreement without the approval of any holders of the Rights, any such supplement or amendment to be evidenced by a writing signed by the Company and the Rights Agent; and

WHEREAS, the Company has determined, and has so directed the Rights Agent, to amend the Rights Agreement as set forth herein pursuant to Section 27 of the Rights Agreement.

NOW, THEREFORE, in consideration of premises and the mutual agreements herein set forth, the parties hereto agree as follows:

1. Section 1 of the Rights Agreement is deleted in its entirety and restated to read as follows:

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

(a) “Acquiring Person” shall mean any Person who or which, together with all Affiliates and Associates of such Person, is at any time from and after the Effective

Time the Beneficial Owner of 4.95% or more of the Common Shares then outstanding; provided, however, that (x) in determining whether a Person is an “Acquiring Person”, any Common Shares acquired in an Exempt Transaction shall not be included as beneficially owned by such Person and (y) the term “Acquiring Person” shall not include any Grandfathered Person, unless such Grandfathered Person becomes the Beneficial Owner of a percentage of Common Shares then outstanding equal to or exceeding such Grandfathered Person’s Grandfathered Percentage. Notwithstanding the foregoing, (i) the term Acquiring Person shall not include (A) the Company, (B) any Subsidiary (as such term is hereinafter defined) of the Company, (C) any employee benefit or compensation plan of the Company or any Subsidiary of the Company, or (D) any entity holding Common Shares for or pursuant to the terms of any employee benefit or compensation plan of the Company or any Subsidiary of the Company, and (ii) no Person shall become an “Acquiring Person” either:

(A) 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 4.95% (or in the case of a Grandfathered Person, the Grandfathered Percentage applicable to such Grandfathered Person) or more of the Common Shares then outstanding; provided, however, that if a Person shall become the Beneficial Owner of 4.95% (or in the case of a Grandfathered Person, the Grandfathered Percentage applicable to such Grandfathered Person) or more of the Common Shares then outstanding by reason of share purchases by the Company and shall, following written notice from, or public disclosure by the Company of such share purchases by the Company, then become the Beneficial Owner of any additional Common Shares without the prior consent of the Company and shall then Beneficially Own more than 4.95% (or in the case of a Grandfathered Person, the Grandfathered Percentage applicable to such Grandfathered Person) of the Common Shares then outstanding, then such Person shall be deemed to be an “Acquiring Person,” or

(B) as the result of the acquisition of Common Shares directly from the Company, provided however that if a Person shall become the Beneficial Owner of 4.95% (or in the case of a Grandfathered Person, the Grandfathered Percentage applicable to such Grandfathered Person) or more of the Common Shares then outstanding by reason of share purchases directly from the Company and shall, after that date, become Beneficial Owner of any additional Common Shares without the prior written consent of the Company and shall then Beneficially Own more than 4.95% (or in the case of a Grandfathered Person, the Grandfathered Percentage applicable to such Grandfathered Person) of the Common Shares then outstanding, then such Person shall be deemed to be an “Acquiring Person”, or

(C) if the Board of Directors determines in good faith that a Person who would otherwise be an “Acquiring Person,” as defined

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pursuant to the foregoing provisions of this paragraph (a), has become such inadvertently (including, without limitation, because (1) such Person was unaware that it beneficially owned a percentage of Common Shares that would otherwise cause such Person to be an “Acquiring Person” or (2) such Person was aware that it was the Beneficial Owner of 4.95% (or in the case of a Grandfathered Person, the Grandfathered Percentage applicable to such Grandfathered Person) or more of the Common Shares outstanding but had no actual knowledge of the consequences of being such a Beneficial Owner under this Agreement) and without any plan or intention of obtaining, changing or influencing control of the Company, such inadvertent acquisition did not result in the loss or impairment of Tax Attributes, and such Person promptly enters into an irrevocable written commitment in favor of the Company to divest, and thereafter divests (without retaining any power, including voting with respect to such Common Shares), as promptly as practicable (as determined in good faith by the Board of Directors), following receipt of written notice from the Company of such event, of Beneficial Ownership of a sufficient number of Common Shares so that such Person would no longer be an Acquiring Person, as defined pursuant to the foregoing provisions of this paragraph (a), then such Person shall not be deemed to be an “Acquiring Person” for any purposes of this Agreement; provided, however, that if such Person shall again become the Beneficial Owner of 4.95% (or in the case of a Grandfathered Person, the Grandfathered Percentage applicable to such Grandfathered Person) or more of the Common Shares then outstanding, such Person shall be deemed an “Acquiring Person,” subject to the exceptions set forth in this Section 1(a).

(b) “Affiliate” and “Associate” shall have the respective meanings ascribed to such terms in Rule 12b-2 of the General Rules and Regulations (the “Rules”) under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), as in effect on the date of this Agreement, and, to the extent not included within the foregoing, shall also include with respect to any Person, any other Persons whose Common Shares would be deemed constructively owned by such first Person or whose Common Shares otherwise would be aggregated with Common Shares owned by such first Person pursuant to the provisions of Section 382; provided that no Person who is a director or officer of the Company shall be deemed an Affiliate or an Associate of any other director or officer of the Company solely as a result of his her or position as director or officer of the Company.

(c) A Person shall be deemed the “Beneficial Owner” or to have “Beneficial Ownership” of and shall be deemed to “beneficially own” any securities:

(i) which such Person or any of such Person’s Affiliates or Associates, directly or indirectly, beneficially owns (as determined pursuant to Rule 13d-3 of the Rules under the Exchange Act, as in effect on the date of this Agreement); provided that a Person shall not be deemed the “Beneficial Owner” of, or to “beneficially own” securities (including rights, options or warrants)

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which are convertible or exchangeable into or exercisable for Common Shares except to the extent that upon the acquisition or transfer of such rights, options or warrants, such rights, options or warrants would be treated as exercised under Section 1.382-4(d) or other applicable sections of the Treasury Regulations;

(ii) which such Person or any of such Person’s Affiliates or Associates, directly or indirectly, has:

(A) the legal, equitable or contractual right or obligation to acquire (whether directly or indirectly, whether such right is exercisable or is required to be exercised immediately or only after the passage of time, compliance with regulatory requirements, fulfillment of a condition or otherwise, or whether within the control of such Person) 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), including, without limitation, for the avoidance of doubt, through any agreement to enter into an agreement that would permit a Person to purchase or otherwise acquire such securities, or upon the exercise of conversion rights, exchange rights, rights (other than the Rights), warrants or options, or otherwise and including any securities represented by “when-issued” trading thereof; provided that a Person shall not be deemed the “Beneficial Owner” of, or to “beneficially own” securities (including rights, options or warrants) which are convertible or exchangeable into or exercisable for Common Shares except to the extent that upon the acquisition or transfer of such rights, options or warrants, such rights, options or warrants would be treated as exercised under Section 1.382-4(d) or other applicable sections of the Treasury Regulations; provided, further, that a Person shall not be deemed the “Beneficial Owner” of, or to “beneficially own” or have “Beneficial Ownership” of, (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; (2) securities issuable upon exercise of Rights at any time prior to the occurrence of an event described in Section 11(a)(ii) or any event described in clause (x), (y) or (z) of the first sentence of Section 13; or (3) securities issuable upon exercise of Rights from and after the occurrence of an event described in Section 11(a)(ii) or any event described in clause (x), (y) or (z) of the first sentence of Section 13, which Rights were acquired by such Person or any of such Person’s Affiliates or Associates prior to the Distribution Date or pursuant to Sections 3(a), 11(i) or 22; or

(B) the right to vote pursuant to any agreement, arrangement or understanding (whether or not in writing), but only if the effect of such agreement, arrangement or understanding is to treat such Person as an “entity” under Section 1.382-3(a)(1) or other applicable sections of the

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Treasury Regulations; provided that a Person shall not be deemed the “Beneficial Owner” of, or to “beneficially own” or have “Beneficial Ownership” of, any security under this clause (B) if (1) the agreement, arrangement or understanding to vote such security (i) arises solely from a revocable proxy or consent given in response to a public proxy or consent solicitation made pursuant to a written proxy or consent solicitation statement filed with the Securities and Exchange Commission, in accordance with the Rules under the Exchange Act and (ii) is not also reportable by such Person on Schedule 13D or Schedule 13G under the Exchange Act (or any comparable or successor report), or (2) if such “Beneficial Ownership” arises solely as a result of such Person’s status as a “clearing agency” as defined in the Exchange Act; or

(C) the right to dispose of, pursuant to any agreement, arrangement or understanding, whether or not in writing (other than customary arrangements with and between underwriters and selling group members with respect to a bona fide public offering of securities), but only if the effect of such agreement, arrangement or understanding is to treat such Person as an “entity” under Section 1.382-3(a)(1) or other applicable sections of the Treasury Regulations;

(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 pursuant to a revocable proxy or consent as provided in clause (B) of Section 1(c)(ii)) or disposing of any securities of the Company, but only if the effect of such agreement, arrangement or understanding is to treat such Person as an “entity” under Section 1.382-3(a)(1) or other applicable sections of the Treasury Regulations; or

(iv) which such Person would be deemed to constructively own or which otherwise would be aggregated with shares owned by such Person pursuant to Section 382;

provided that (1) no Person engaged in business as an underwriter of securities shall be deemed the Beneficial Owner of any securities acquired through such Person’s participation as an underwriter in good faith in a firm commitment underwriting until the expiration of forty (40) days after the date of such acquisition, and (2) no Person who is a director or an officer of the Company shall be deemed, as a result of his or her position as director or officer of the Company, the Beneficial Owner of any securities of the Company that are Beneficially Owned by any other director or officer of the Company.

For all purposes of this Agreement, any calculation of the number of Common Shares, which, for purposes of this paragraph, shall include any other interest that would be

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treated as “stock” of the Company for purposes of Section 382, including but not limited to pursuant to Treasury Regulation Section 1.382-2T(f)(18), outstanding at any particular time, for purposes of determining the particular percentage of such outstanding Common Shares of which any Person is the Beneficial Owner, shall be made pursuant to and in accordance with Section 382.

(d) “Business Day” shall mean any day other than a Saturday, a Sunday, or a day on which banking institutions in the State of Washington or the State of New Jersey (or such other state in which the principal office of the Rights Agent is located), are authorized or obligated by law or executive order to close.

(e) “Close of Business” on any given date shall mean 5:00 p.m., Pacific Time, on such date; provided, however, that if such date is not a Business Day it shall mean 5:00 p.m., Pacific Time, on the next succeeding Business Day.

(f) “Code” shall mean Internal Revenue Code of 1986, as amended.

(g) “Common Shares” shall mean the shares of common stock, par value $.001 per share, of the Company or any other shares of capital stock of the Company in to which such stock shall be reclassified or changes, and any other interest that would be treated as “stock” of the Company for purposes of Section 382 (including but not limited to pursuant to Treasury Regulation Section 1.382-2T(f)(18)) in this Section 1 and all other provisions of this Agreement in which such meaning is necessary in order to ensure that this Agreement is effective in carrying out its stated purpose and intent of preserving the Company’s Tax Attributes; provided, however, that, “Common Shares,” when used in this Agreement in connection with a specific reference to any Person other than the Company, shall mean the capital stock (or equity interest) with the greatest voting power of such other Person or, if such other Person is a Subsidiary of another Person, the Person or Persons which ultimately control such first-mentioned Person.

(h) “Distribution Date” shall have the meaning set forth in Section 3 hereof.

(i) “Effective Time” shall mean the initial public announcement of this Amendment.

(j) “Exempt Transaction” shall mean any transaction that the Board of Directors determines, in its sole discretion, is exempt from this Agreement, which determination shall be made in the sole and absolute discretion of the Board of Directors prior to the date of such transaction or within ten Business Days after such transaction, including, without limitation, if the Board of Directors determines that (i) neither the beneficial ownership of Common Shares by any Person, directly or indirectly, as a result of such transaction nor any other aspect of such transaction would jeopardize or endanger the availability to the Company of the Tax Attributes or (ii) such transaction is otherwise in the best interests of the Company. In granting an exemption under this definition, the Board of Directors may require any Person who would otherwise be an Acquiring Person to make certain representations or undertakings or to agree that any violation or attempted violation of such representations or undertakings will result in such

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consequences and subject to such conditions as the Board of Directors may determine in its sole discretion, including that any such violation shall result in such Person becoming an Acquiring Person.

(k) “Final Expiration Date” shall have the meaning set forth in Section 7(a) hereof.

(l) “Grandfathered Percentage” shall mean, with respect to any Grandfathered Person, the percentage of the outstanding Common Shares of the Company that such Grandfathered Person, together with all Affiliates and Associates of such Grandfathered Person, Beneficially Owns as of the Effective Time; provided that, in the event any Grandfathered Person shall sell, transfer, or otherwise dispose of any outstanding Common Shares of the Company after the Effective Time, the Grandfathered Percentage shall, subsequent to such sale, transfer or disposition, mean, with respect to such Grandfathered Person, the lesser of (i) the Grandfathered Percentage as in effect immediately prior to such sale, transfer or disposition or (ii) the percentage of outstanding Common Shares of the Company that such Grandfathered Person Beneficially Owns immediately following such sale, transfer or disposition.

(m) “Grandfathered Person” shall mean any Person who or which, together with all Affiliates and Associates of such Person, is, as of the Effective Time, the Beneficial Owner of 4.95% or more of the Common Shares of the Company then outstanding. Notwithstanding anything to the contrary provided in this Agreement, any Grandfathered Person who after the Effective Time becomes the Beneficial Owner of less than 4.95% of the Common Shares of the Company then outstanding shall cease to be a Grandfathered Person and shall be subject to all of the provisions of this Agreement in the same manner as any Person who is not and was not a Grandfathered Person.

(n) “Interested Stockholder” shall mean any Acquiring Person or any Affiliate or Associate of an Acquiring Person or any other Person in which any such Acquiring Person, Affiliate or Associate has an interest, or any other Person acting directly or indirectly on behalf of or in concert with any such Acquiring Person, Affiliate or Associate.

(o) “Person” shall mean (i) any individual, firm, corporation, limited liability company, partnership, association, trust or any other entity, and shall include any successor (by merger or otherwise) of such entity or (b) group of Persons making a “coordinated purchase” of Common Shares or otherwise treated as an entity within the meaning of Section 1.382-3(a)(1) of the Treasury Regulations, and shall include any successor by merger or otherwise of such individual entity, as well as any group under Rule 13d-5(b)(1) under the Exchange Act but shall not include a Public Group (as defined in Section 1.382-2T(f)(13) of the Treasury Regulations).

(p) “Preferred Shares” shall mean shares of Series A Junior Participating Preferred Stock, par value $.001 per share, of the Company having the designations and the powers, preferences and rights, and the qualifications, limitations and restrictions set forth in the Certificate of Designation filed with the Delaware Secretary of State on September 23, 2002, as amended from time to time.

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(q) “Purchase Price” shall have the meaning set forth in Section 7(b) hereof.

(r) “Redemption Date” shall have the meaning set forth in Section 7(a) hereof.

(s) “Section 382” shall mean Section 382 of the Code, or any successor provision or replacement provision.

(t) “Shares Acquisition Date” shall mean the first date of public announcement by the Company that an Acquiring Person exists, or by an Acquiring Person that such Person has become an Acquiring Person; provided, however that, if such Person is determined not to have become an Acquiring Person pursuant to clause (C) of Subsection 1(a)(ii) hereof, then no Shares Acquisition Date shall be deemed to have occurred.

(u) “Subsidiary” of any Person shall mean any Person or other entity of which a majority of the voting power of the voting equity securities or equity interest is owned, directly or indirectly, by such Person.

(v) “Tax Attributes” shall mean the net operating loss carryovers, capital loss carryovers, general business carryovers, alternative minimum tax credit carryovers, foreign tax credit carryovers, and any other tax credit carryovers, as well as any loss or deduction attributable to a “net unrealized built-in loss” within the meaning of Section 382, of the Company and its Subsidiaries.

(w) “Treasury Regulations” shall mean final, temporary and proposed tax regulations promulgated under the Code, including any amendments thereto.

(x) “Trust” and “Trust Agreement” shall have the meanings set forth in Section 24(c) hereof.

2. Section 3(a) of the Rights Agreement is deleted in its entirety and restated to read as follows:

“(a) Until the earlier of the Close of Business on (i) the tenth Business Day (or such later date as may be determined by action of the Board of Directors) after the Shares Acquisition Date or (ii) the tenth Business Day (or such later date as may be determined by action of the Board of Directors) after the date of the commencement (determined in accordance with Rule 14d-2 under the Exchange Act) by any Person (other than the Company, any Subsidiary of the Company, any employee benefit plan of the Company or of any Subsidiary of the Company or any entity holding Common Shares for or pursuant to the terms of any such plan) of, or of the first public announcement of the intention of any Person (other than the Company, any Subsidiary of the Company, any employee benefit plan of the Company or of any Subsidiary of the Company or any entity holding Common Shares for or pursuant to the terms of any such plan) to commence, a tender or

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exchange offer (which intention to commence remains in effect for five Business Days after such announcement), the consummation of which would result in any Person becoming an Acquiring Person (including any such date which is after the date of this Agreement and prior to the issuance of the Rights, the earlier of such dates being herein referred to as the “Distribution Date”), (x) the Rights will be evidenced by the certificates for Common Shares registered in the names of the holders thereof (which certificates shall also be deemed to be Right Certificates) and not by separate Right Certificates, and (y) the Rights (and the right to receive Right Certificates therefor) will be transferable only in connection with the transfer of Common Shares. As soon as practicable after the Distribution Date, the Company will prepare and execute, the Rights Agent will countersign, and the Company will send or cause to be sent (and the Rights Agent will, if requested and provided with a list of all the record holders and of Common Shares and all other necessary information and documents, send at the expense of the Company) by first-class, insured, postage-prepaid mail, to each record holder of Common Shares as of the Close of Business on the Distribution Date, at the address of such holder shown on the records of the Company, a Right Certificate, in substantially the form of Exhibit B hereto (a “Right Certificate”), evidencing one Right for each Common Share so held, subject to the adjustment provisions of Section 11 of this Agreement. As of the Distribution Date, the Rights will be evidenced solely by such Right Certificates. The Company shall as promptly as practicable 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 Business Day next following. Until such notice has been received by the Rights Agent, the Rights Agent may presume conclusively for all purposes that the Distribution Date has not occurred.”

3. Section 6 of the Rights Agreement is deleted in its entirety and restated to read as follows:

“SECTION 6. TRANSFER, SPLIT UP, COMBINATION AND EXCHANGE OF RIGHTS CERTIFICATES; MUTILATED, DESTROYED, LOST OR STOLEN RIGHTS CERTIFICATES. Subject to the provisions of Section 11(a)(ii), Section 14 and Section 24 hereof, at any time after the Close of Business on the Distribution Date, and at or prior to the Close of Business on the earlier of the Redemption Date or the Final Expiration Date, any Right Certificate or Right Certificates may be transferred, split up, combined or exchanged for another Right Certificate or Right Certificates, entitling the registered holder to purchase a like number of one one-hundredths of a Preferred Share as the Right Certificate or Right Certificates surrendered then entitled such holder to purchase. Any registered holder desiring to transfer, split up, combine or exchange any Right Certificate or Right Certificates shall make such request in writing delivered to the Rights Agent, and shall surrender the Right Certificate or Right Certificates to be transferred, split up, combined or exchanged at an office or agency designated for such purpose by 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 Right Certificate until the registered holder shall have properly completed and duly executed, with signature guaranteed, the certificate contained in the form of assignment on the reverse side of such Right Certificate and shall have provided such additional evidence of the identity of the Beneficial Owner (or former Beneficial Owner) or Affiliates or Associates thereof as the

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Company or the Rights Agent shall reasonably request. Thereupon the Rights Agent shall, subject to Section 11(a)(ii), Section 14 and Section 24 hereof, countersign (by manual or facsimile signature) and deliver to the Person entitled thereto a Right Certificate or Right Certificates, as the case may be, as so requested. The Company may require payment of a sum sufficient to cover any tax or charge that may be imposed in connection with any transfer, split up, combination or exchange of Right Certificates. If and to the extent the Company does require payment of any such taxes or charges, the Company shall give the Rights Agent prompt written notice thereof and the Rights Agent shall not deliver any Right Certificate unless and until it is satisfied that all such payments have been made, and the Rights Agent shall forward any such sum collected by it to the Company or to such Persons as the Company may specify by written notice. The Rights Agent shall have no duty or obligation under any section of this Agreement which requires the payment by a Rights holder of applicable taxes and charges unless and until the Rights Agent is satisfied that all such taxes and/or charges have been paid.

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

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

4. Section 7(a) of the Rights Agreement is deleted in its entirety and restated to read as follows:

“(a) The registered holder of any Right Certificate may exercise the Rights evidenced thereby (except as otherwise provided herein) in whole or in part at any time after the Distribution Date upon surrender of the Right Certificate, with the form of election to purchase on the reverse side thereof properly completed and duly executed, with signature guaranteed, to the Rights Agent at the office of the Rights Agent designated for such purpose, together with payment of the Purchase Price for each one one-hundredth of a Preferred Share (or such other number of shares or other securities) as to which the Rights are exercised, at or prior to the earliest of (i) the Close of Business on May 3, 2015 (the “Final Expiration Date”), (ii) the time at which the Rights are redeemed as provided in Section 23 hereof (the “Redemption Date”), (iii) the time at which such Rights are exchanged as provided in Section 24 hereof, (iv) the repeal of Section 382 if the Board of Directors determines that this Agreement is no longer necessary for the preservation of Tax Attributes or (v) the beginning of the taxable year of the Company to which the Board of Directors determines that no Tax Attributes may be carried forward.”

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5. Section 7(c) of the Rights Agreement is deleted in its entirety and restated to read as follows:

“(c) Upon receipt of a Right Certificate representing exercisable Rights, with the form of election to purchase properly completed and duly executed, with signature guaranteed, accompanied by payment of the Purchase Price for the shares to be purchased and an amount equal to any applicable tax or charge required to be paid by the holder of such Right Certificate in accordance with Section 9 hereof by cash or certified check, cashier’s check, bank draft or money order payable to the order of the Company, the Rights Agent shall thereupon promptly (i) (A) requisition from any transfer agent for the Preferred Shares certificates (or make available, if the Rights Agent is the transfer agent) for the number of Preferred Shares to be purchased and the Company hereby irrevocably authorizes its transfer agent to comply with all such requests, or (B) if the Company, in its sole discretion, shall have elected to deposit the Preferred Shares issuable upon exercise of the Rights hereunder into a depository, requisition from the depositary agent depositary receipts representing such number of one one-hundredths of a Preferred Share as are to be purchased (in which case certificates for the Preferred Shares represented by such receipts shall be deposited by the transfer agent with the depositary agent) and the Company hereby directs the depositary agent to comply with such request, (ii) when necessary to comply with this Agreement, requisition from the Company the amount of cash to be paid in lieu of issuance of fractional shares in accordance with Section 14 hereof, (iii) after receipt of such certificates or depositary receipts (or confirmation or written notice that an entry has been made in the bookentry account system of the transfer agent), cause the same to be delivered to or upon the order of the registered holder of such Right Certificate, registered in such name or names as may be designated by such holder and (iv) when necessary to comply with this Agreement, after receipt, deliver such cash to or upon the order of the registered holder of such Right Certificate. In the event that the Company is obligated to issue securities of the Company other than Preferred Shares (including Common Shares) of the Company pursuant to Section 11(a) hereof, the Company will make all arrangements necessary so that such other securities are available for distribution by the Rights Agent, if and when necessary to comply with this Agreement.”

6. Section 11(a)(ii) of the Rights Agreement is deleted in its entirety and restated to read as follows:

“(ii) Subject to Section 24 hereof and the provisions of the next paragraph of this Section 11(a)(ii), in the event any Person shall become an Acquiring Person, each holder of a Right shall have a right to receive, upon exercise thereof at a price equal to the then current Purchase Price multiplied by the number of one one-hundredths of a Preferred Share for which a Right is then exercisable, in accordance with the terms of this Agreement and in lieu of Preferred Shares, such number of Common Shares as shall equal the result obtained by (A) multiplying the then current Purchase Price by the number of one one-hundredths of a Preferred Share for which a Right is then exercisable and dividing that product by (B) 50% of the then current per share market price of the Common Shares (determined pursuant to Section 11(d) hereof) on the date such

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Person became an Acquiring Person; provided, however, that upon the consummation of any transaction subject to the provisions of Section 13(a) hereof, then only the provisions of Section 13 hereof shall apply and the provisions of this Section 11(a)(ii) shall be of no further force or effect.

Notwithstanding anything in this Agreement to the contrary, from and after the time any Person becomes an Acquiring Person, any Rights beneficially owned by (i) such Acquiring Person or an Associate or Affiliate of such Acquiring Person, (ii) a transferee of such Acquiring Person (or of any such Associate or Affiliate) who becomes a transferee after the Acquiring Person became such, or (iii) a transferee of such Acquiring Person (or of any such Associate or Affiliate) who becomes a transferee prior to or concurrently with the Acquiring Person’s becoming such and receives such Rights pursuant to either (A) a transfer (whether or not for consideration) from the Acquiring Person to holders of equity interests in such Acquiring Person or to any Person with whom the Acquiring Person has any continuing agreement, arrangement or understanding regarding the transferred Rights or (B) a transfer which the Board of Directors has determined is part of a plan, agreement, arrangement or understanding which has as a primary purpose or effect the avoidance of this Section 11(a)(ii), shall become null and void without any further action and no holder of such Rights shall have any rights whatsoever with respect to such Rights, whether under any provision of this Agreement or otherwise. The Company shall notify the Rights Agent when this Section 11(a)(ii) applies and shall use all reasonable efforts to insure that the provisions of this Section 11(a)(ii) and Section 4(b) hereof are complied with, but neither the Company nor the Rights Agent shall have any liability to any holder of Right Certificates or other Person as a result of the Company’s failure to make any determinations with respect to an Acquiring Person or its Affiliates, Associates or transferees hereunder. No Right Certificate shall be issued at any time upon the transfer of any Rights to an Acquiring Person whose Rights would be null and void pursuant to the second preceding sentence or any Associate or Affiliate thereof or to any nominee of such Acquiring Person, Associate or Affiliate; and any Right Certificate delivered to the Rights Agent for transfer to an Acquiring Person whose Rights would be null and void pursuant to the second preceding sentence shall be canceled.

In the event that any Person shall become an Acquiring Person and the Rights shall then be outstanding, the Company shall not take any action which would eliminate or diminish the benefits intended to be afforded by the Rights.”

7. Section 13(a) of the Rights Agreement is deleted in its entirety and restated to read as follows:

“(a) In the event that, following the Shares Acquisition Date, directly or indirectly (x) the Company shall consolidate with, or merge with and into, any other Person (other than a Subsidiary of the Company in a transaction which does not violate Section 11(n) hereof), (y) any other Person (other than a Subsidiary of the Company in a

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transaction which does not violate Section 11(n) hereof) shall consolidate with the Company, or merge with and into the Company, and the Company shall be the continuing or surviving corporation of such merger (other than, in the case of either transaction described in (x) or (y), a merger or consolidation which would result in all of the voting power represented by the securities of the Company outstanding immediately prior thereto continuing to represent (either by remaining outstanding or by being converted into securities of the surviving entity) all of the voting power represented by the securities of the Company or such surviving entity outstanding immediately after such merger or consolidation and the holders of such securities not having changed as a result of such merger or consolidation), or (z) the Company shall sell 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 more than 50% of the assets or earning power of the Company and its Subsidiaries (taken as a whole) to any other Person, (other than the Company or any Subsidiary of the Company in one or more transactions each of which individually and the aggregate does not violate Section 11(n) hereof) then, and in each such case, proper provision shall be made so that (i) each holder of a Right, subject to Section 11(a)(ii) hereof, shall have the right to receive, upon the exercise thereof at a price equal to the then current Purchase Price multiplied by the number of one one-hundredths of a Preferred Share for which a Right is then exercisable in accordance with the terms of this Agreement and in lieu of Preferred Shares, such number of freely tradeable Common Shares of the Principal Party (as such term is hereinafter defined), free and clear of liens, rights of call or first refusal, encumbrances or other adverse claims, as shall be equal to the result obtained by (A) multiplying the then current Purchase Price by the number of one one-hundredths of a Preferred Share for which a Right is then exercisable (without taking into account any adjustment previously made pursuant to Section 11(a)(ii) hereof) and dividing that product by (B) 50% of the then current per share market price of the Common Shares of such Principal Party (determined pursuant to Section 11(d) hereof) on the date of consummation of such consolidation, merger, sale or transfer; (ii) such Principal Party shall thereafter be liable for, and shall assume, by virtue of such consolidation, merger, sale or transfer, all the obligations and duties of the Company pursuant to this Agreement; (iii) the term “Company” shall thereafter be deemed to refer to such Principal Party, it being specifically intended that the provisions of Section 11 hereof shall apply to such Principal Party; and (iv) such Principal Party shall take such steps (including, but not limited to, the reservation of a sufficient number of shares of its Common Shares in accordance with Section 9 hereof) in connection with such consummation as may be necessary to assure that the provisions hereof shall thereafter be applicable, as nearly as reasonably may be, in relation to its Common Shares thereafter deliverable upon the exercise of the Rights.”

8. A new Section 14(e) shall be added to the Rights Agreement as follows:

“(e) Whenever a payment for fractional Rights or fractional shares is to be made by the Rights Agent under any section of this Agreement, 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

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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.”

9. Section 16 of the Rights Agreement is deleted in its entirety and restated to read as follows:

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

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

(b) after the Distribution Date, the Right Certificates are transferable (subject to the provisions of this Agreement) only on the registry books of the Rights Agent if surrendered at an office or agency designated for such purpose by the Rights Agent, duly endorsed or accompanied by a proper instrument of transfer and with the appropriate forms and certificates properly completed and duly executed;

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

(d) 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, judgment, decree or ruling (whether interlocutory or final) issued by a court of competent jurisdiction or by a governmental, regulatory, self-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, the Company must use its best efforts to have any such injunction, order, judgment, decree or ruling lifted or otherwise overturned as soon as possible.”

10. Section 18 of the Rights Agreement is deleted in its entirety and restated to read as follows:

“SECTION 18. CONCERNING THE RIGHTS AGENT. The Company agrees to pay to the Rights Agent reasonable compensation for all services rendered by it hereunder

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and, from time to time, on demand of the Rights Agent, its reasonable expenses and counsel fees and other disbursements incurred in the preparation, delivery, amendment, administration and execution of this Agreement and the exercise and performance of its rights and 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 (provided, however, that the Company shall not be responsible for any settlement entered into without its prior written consent, which shall not be unreasonably withheld), 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 must be determined by a final, nonappealable order, judgment, decree or ruling of a court of competent jurisdiction), for any action taken, suffered or omitted to be taken by the Rights Agent in connection with the acceptance, administration, exercise and performance of its duties under this Agreement, including without limitation the costs and expenses of defending against any claim of liability in the premises. The costs and expenses incurred in enforcing this right of indemnification shall be paid by the Company. The provisions of this Section 18 and Section 20 below shall survive the termination of this Agreement, the exercise or expiration of the Rights and the resignation or removal of the Rights Agent.

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

11. Section 19 of the Rights Agreement is deleted in its entirety and restated to read as follows:

“SECTION 19. MERGER OR CONSOLIDATION OR CHANGE OF NAME OF RIGHTS AGENT. 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 or corporate trust business of the Rights Agent or any successor Rights Agent, shall be the successor to the Rights Agent under this Agreement without the execution or filing of any paper or any further act on the part of any of the parties hereto, provided that such Person would be eligible for appointment as a successor Rights Agent under the provisions of Section 21 hereof. The purchase of all or substantially all of the Rights Agent’s assets employed in the performance of transfer agent activities shall be deemed a merger or consolidation for purposes of this Section 19. In case at the time such successor Rights Agent shall succeed to the agency created by this Agreement any of the Right Certificates shall have been

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

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

12. The introductory paragraph of Section 20 of the Rights Agreement is deleted in its entirety and restated to read as follows:

“SECTION 20. DUTIES OF THE RIGHTS AGENT. The Rights Agent undertakes to perform only the duties and obligations expressly set forth in this Agreement (and no implied duties or obligations), upon the following terms and conditions, by all of which the Company and the holders of Right Certificates, by their acceptance thereof, shall be bound:”

13. Section 20(g) of the Rights Agreement is deleted in its entirety and restated to read as follows:

“(g) The Rights Agent is hereby authorized and directed to accept instructions with respect to the performance of its duties hereunder from any one of the Chairman of the Board, the Chief Executive Officer, the President, the Chief Financial Officer, any Vice President, the Secretary or the Treasurer of the Company, and to apply to such officers for advice or instructions in connection with its duties, and such advice or instructions shall be full authorization and protection to the Rights Agent and the Rights Agent shall not be liable for or in respect of any action taken, suffered or omitted to be taken by it in the absence of bad faith on the part of the Rights Agent (which must be determined by a final, nonappealable order, judgment, decree or ruling of a court of competent jurisdiction) in accordance with the advice or instructions of any such officer or for any delay in acting while waiting for those instructions. The Rights Agent shall be fully authorized and protected in relying upon the most recent instructions received by any such officer. 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 to be taken by the Rights Agent pursuant to 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

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in any such application on or after the date specified in such application (which date shall not be less than three Business Days after the date any officer of the Company actually receives such application unless any such officer shall have consented in writing to an earlier date) unless, prior to taking or omitting any such action, the Rights Agent shall have received written instructions in response to such application specifying the action to be taken, suffered or omitted to be taken.”

14. A new Section 20(l) shall be added to the Rights Agreement as follows:

“(l) The Rights Agent shall not be required to take notice or be deemed to have notice of any fact, event or determination (including, without limitation, any dates or events defined in this Agreement or the designation of any Person as an Acquiring Person, Affiliate or Associate) under this Agreement unless and until the Rights Agent shall be specifically notified in writing by the Company of such fact, event or determination.”

15. Section 23(b) of the Rights Agreement is deleted in its entirety and restated to read as follows:

“(b) The Board of Directors may, at its option, at any time prior to the earlier of (A) the tenth Business Day (or such later date as may be determined by action of the Board of Directors) after such time as any Person becomes an Acquiring Person, or (B) the Final Expiration Date, redeem all but not less than all of the then outstanding Rights at a redemption price of $0.001 per Right, appropriately adjusted to reflect any stock split, stock dividend or similar transaction occurring after the date hereof (such redemption price being hereinafter referred to as the “Redemption Price”), and the Company may, at its option, pay the Redemption Price in Common Shares (based on the “current per share market price,” as such term is defined in Section 11(d) hereof, of the Common Shares at the time of redemption), cash or any other form of consideration deemed appropriate by the Board of Directors. The redemption of the Rights by the Board of Directors may be made effective at such time, on such basis and subject to such conditions as the Board of Directors in its sole discretion may establish. Notwithstanding anything contained in this Agreement to the contrary, the Rights shall not be exercisable pursuant to Section 11(a)(ii) hereof prior to the expiration or termination of the Company’s right of redemption under this Section 23(b).”

16. Section 24 of the Rights Agreement is deleted in its entirety and restated to read as follows:

“SECTION 24. EXCHANGE.

(a) The Board of Directors may, at its option, at any time after any Person becomes an Acquiring Person, exchange all or part of the then outstanding and exercisable Rights (which (i) shall not include Rights that have become void pursuant to the provisions of Section 11(a)(ii) hereof, and (ii) shall include, without limitation, any Rights issued after the Distribution Date) for Common Shares at an exchange ratio of one Common Share per Right, appropriately adjusted to reflect any stock split, stock dividend

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or similar transaction occurring after the date hereof (such exchange ratio being hereinafter referred to as the “Exchange Ratio”). Notwithstanding the foregoing, the Board of Directors shall not be empowered to effect such exchange at any time after any Person (other than the Company, any Subsidiary of the Company, any employee benefit plan of the Company or any such Subsidiary, or any entity holding Common Shares for or pursuant to the terms of any such plan), together with all Affiliates and Associates of such Person, becomes the Beneficial Owner of 50% or more of the Common Shares then outstanding.

(b) Immediately upon the action of the Board of Directors ordering the exchange of any Rights pursuant to Section 24(a) hereof, evidence of which shall have been filed with the Rights Agent, and without any further action and without any notice, the right to exercise such Rights shall terminate and the only right thereafter of a holder of such Rights shall be to receive that number of Common Shares equal to the number of such Rights held by such holder multiplied by the Exchange Ratio; provided, that the holder of a Right exchanged pursuant to this Section 24 shall continue to have the right to purchase securities or other property of the Principal Party following the occurrence of an event described in the first sentence of Section 13(a) hereof that has occurred or may thereafter occur. The Company shall promptly give public notice (with prompt written notice thereof to the Rights Agent) of any such exchange; provided, that the failure to give, or any defect in, such notice shall not affect the validity of such exchange. The Company promptly shall mail a notice of any such exchange to all of the holders of such Rights at their last addresses as they appear upon the registry books of the Rights Agent. 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 shall state the method by which the exchange of 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 11(a)(ii) hereof) held by each holder of Rights.

(c) In any exchange pursuant to this Section 24, the Company, at its option, may substitute Preferred Shares (or equivalent preferred shares) for Common Shares exchangeable for Rights, at the initial rate of one one-hundredth of a Preferred Share (or equivalent preferred shares) for each Common Share, as appropriately adjusted to reflect adjustments in the voting rights of the Preferred Shares pursuant to the terms thereof, so that the fraction of a Preferred Share delivered in lieu of each Common Share shall have the same voting rights as one Common Share.

(d) Following the action of the Board of Directors ordering the exchange of any Rights pursuant to this Section 24, the Company may implement such procedures as it deems appropriate, in its sole discretion, for the purpose of ensuring that Common Shares (or such other consideration) issuable upon an exchange pursuant to this Section 24 is not received by holders of Rights that have become null and void pursuant to Section 11(a)(ii) hereof. Before effecting an exchange pursuant to this Section 24, the Board of Directors may direct the Company to enter into a Trust Agreement in such form and with such terms as the Board of Directors shall then approve (the “Trust

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Agreement”). If the Board of Directors so directs, the Company shall enter into the Trust Agreement and shall issue to the trust created by such agreement (the “Trust”) all or a portion (as designated by the Board of Directors) of Common Shares (or other securities) issuable pursuant to the exchange, and all holders of Rights entitled to receive such shares or securities pursuant to the exchange shall be entitled to receive such shares or securities (and any dividends paid or distributions made thereon after the date on which such shares are deposited in the Trust) only from the Trust and solely upon compliance with the relevant terms and provisions of the Trust Agreement. Prior to effecting an exchange and registering Common Shares (or other such securities) in any Person’s name, including any nominee or transferee of a Person, the Company may require (or cause the trustee of the Trust to require), as a condition thereof, that any holder of Rights provide evidence, including, without limitation, the identity of the Beneficial Owners thereof and their Affiliates and Associates (or former Beneficial Owners thereof and their Affiliates and Associates) as the Company shall reasonably request in order to determine if such Rights are null and void. If any Person shall fail to comply with such request, the Company shall be entitled conclusively to deem the Rights formerly held by such Person to be null and void pursuant to Section 11(a)(ii) hereof and not transferable or exercisable or exchangeable in connection herewith. Any Common Shares or other securities issued at the direction of the Board of Directors in connection herewith shall be validly issued, fully paid and nonassessable Common Shares or of such other securities (as the case may be), and the Company shall be deemed to have received as consideration for such issuance a benefit having a value that is at least equal to the aggregate par value of the shares so issued.

(e) In the event that there shall not be sufficient Common Shares or Preferred Shares (or equivalent preferred shares) issued but not outstanding or authorized but unissued to permit any exchange of Rights as contemplated in accordance with this Section 24, the Company shall take all such action as may be necessary to authorize additional Common Shares or Preferred Shares (or equivalent preferred shares) for issuance upon exchange of the Rights.

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

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17. Section 26 of the Rights Agreement is deleted in its entirety and restated to read as follows:

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

Dendreon Corporation

0000 0xx Xxxxxx, Xxxxx 0000

Xxxxxxx, Xxxxxxxxxx 00000

Attn: Corporate Secretary

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

Computershare Shareowner Services LLC

000 Xxxx Xxxxxx, Xxxxx 0000

Xxxxxxx, XX 00000

Attn: Relationship Manager

with a copy to:

Computershare Shareowner Services LLC

000 Xxxxxxxxxx Xxxxxxxxx

Xxxxxx Xxxx, Xxx Xxxxxx 00000

Attention: Legal Department

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

18. Section 31 of the Rights Agreement is deleted in its entirety and restated to read as follows:

“SECTION 31. SEVERABILITY. If any term, provision, covenant or restriction of this Agreement is held by a court of competent jurisdiction or other authority to be invalid, void or unenforceable, the remainder of the terms, provisions, covenants and restrictions of this Agreement shall remain in full force and effect and shall in no way be affected, impaired or invalidated, provided, that if any such invalid, void or unenforceable term, provision, covenant or restriction shall adversely affect the rights, immunities, duties or obligations of the Rights Agent, the Rights Agent shall be entitled to resign immediately.”

19. A new Section 35 shall be added to the Rights Agreement as follows:

“SECTION 35. FORCE MAJEURE. Notwithstanding anything to the contrary contained herein, the Rights Agent shall not be liable for any delays or failures in

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performance resulting from acts beyond its reasonable control including, without limitation, acts of God, terrorist acts, shortage of supply, breakdowns or malfunctions, interruptions or malfunction of computer facilities, or loss of data due to power failures or mechanical difficulties with information storage or retrieval systems, labor difficulties, war, or civil unrest.”

20. A new Section 36 shall be added to the Rights Agreement as follows:

“SECTION 36. USA PATRIOT ACT. Each Person that is a party hereto acknowledges that the Rights Agent is subject to the customer identification program (“Customer Identification Program”) requirements under the USA PATRIOT Act and its implementing regulations, and that the Rights Agent must obtain, verify and record information that allows the Rights Agent to identify each such person or entity. Accordingly, prior to accepting an appointment hereunder, the Rights Agent may request information from any such person or entity that will help the Rights Agent to identify such person or entity, including, without limitation, as applicable, such person or entity’s physical address, tax identification number, organizational documents, certificate of good standing, license to do business, or any other information that the Rights Agent deems necessary. Each Person that is a party hereto acknowledges that the Rights Agent cannot accept an appointment hereunder unless and until the Rights Agent verifies each such person or entity’s identity in accordance with the Customer Identification Program requirements.”

21. Exhibit B of the Rights Agreement is hereby deleted in its entirety and amended and restated as set forth in Annex A hereto.

22. Any legends required under the Rights Agreement need only be in substantially similar form to that set forth in the Rights Agreement and only to the extent the Rights Agent has knowledge thereof and sufficient information with respect thereto.

23. Any reference in the Rights Agreement to countersignature by the Rights Agent may be done by manual or facsimile signature.

24. This Amendment 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 the State of Delaware applicable to contracts to be made and performed entirely within the State of Delaware.

25. This Amendment 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.

26. If any term, provision, covenant or restriction of the Rights Agreement as amended by this Amendment 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 Amendment shall remain in full force and effect and shall in no way be affected, impaired or invalidated; provided, however, that if any such excluded term, provision, covenant or restriction shall adversely affect the rights, immunities, duties or obligations of the Rights Agent, the Rights Agent shall be entitled to resign immediately.

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27. Capitalized terms used herein and not otherwise defined shall have the meanings given to such terms in the Rights Agreement.

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IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be duly executed as of the date first set forth above.

DENDREON CORPORATION
By:		/s/ Xxxxxxxxx Xxxxxx Xxxxxx
		Name:		Xxxxxxxxx Xxxxxx Xxxxxx
		Title:		Executive Vice President, Corporate Development, General Counsel and Secretary
COMPUTERSHARE SHAREOWNER SERVICES LLC
By:		/s/ Xxxxxx Xxxxxx
		Name:		Xxxxxx Xxxxxx
		Title:		Vice President, Relationship Manager

[Signature Page to Amendment No. 1 to Rights Agreement]

ANNEX A

FORM OF RIGHT CERTIFICATE

(EXHIBIT B TO RIGHTS AGREEMENT)

Certificate No. R-             Rights

NOT EXERCISABLE AFTER MAY 3, 2015, OR SUCH EARLIER DATE AS PROVIDED BY THE RIGHTS AGREEMENT OR IF REDEMPTION OR EXCHANGE OCCURS. THE RIGHTS ARE SUBJECT TO REDEMPTION AT $.001 PER RIGHT AND TO EXCHANGE ON THE TERMS SET FORTH IN THE RIGHTS AGREEMENT.

RIGHT CERTIFICATE

DENDREON CORPORATION

This certifies that                      or registered assigns, is the registered owner of the number of Rights set forth above, each of which entitles the owner thereof, subject to the terms, provisions and conditions of the Rights Agreement, dated as of September 18, 2002, between Dendreon Corporation, a Delaware corporation (the “Company”), and Computershare Shareowner Services LLC (the “Rights Agent”), as amended by Amendment No. 1 to Rights Agreement, dated as of May 4, 2012 (the “Rights Agreement”) 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 p.m., Pacific Time, on May 3, 2015, or such earlier date as provided by the Rights Agreement, at the office of the Rights Agent designated for such purpose, or at the office of its successor as Rights Agent, one one-hundredth of a fully paid non-assessable share of Series A Junior Participating Preferred Stock, par value $.001 per share (the “Preferred Shares”), of the Company, at a purchase price of $45.00 per one one-hundredth of a Preferred Share (the “Purchase Price”), upon presentation and surrender of this Right Certificate with the Form of Election to Purchase duly executed and payment of any applicable transfer taxes in accordance with the provisions of the Rights Agreement. The number of Rights evidenced by this Right Certificate (and the number of one one-hundredths of a Preferred Share which may be purchased upon exercise hereof) set forth above, and the Purchase Price set forth above, are the number and Purchase Price as of October 2, 2002, based on the Preferred Shares as constituted at such date.

From and after the time any Person becomes an Acquiring Person (as such terms are defined in the Rights Agreement), if the Rights evidenced by this Right Certificate are beneficially owned by (i) an Acquiring Person or an Affiliate or Associate of any such Acquiring Person (as such terms are defined in the Rights Agreement), (ii) a transferee of any such Acquiring Person, Associate or Affiliate who becomes a transferee after the Acquiring Person becomes such, or (iii) under certain circumstances specified in the Rights Agreement, a transferee of any such Acquiring Person, Associate or Affiliate who becomes a transferee prior to or concurrently with the Acquiring Person becoming such, such Rights shall become null and void without any further action and no holder hereof shall have any right with respect to such Rights from and after the time any Person becomes an Acquiring Person.

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

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

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

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

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

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

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

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

ATTEST:						DENDREON CORPORATION
By:						By:
Print Name:						Print Name:
Title:						Title:
COUNTERSIGNED:
By:
Print Name:
Title:

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For of Reverse Side of Right Certificate

FORM OF ASSIGNMENT

(To be executed by the registered holder if such

holder desires to transfer the Right Certificate.)

FOR VALUE RECEIVED                     hereby sells, assigns and transfers unto                                                                                  

(Please print name and address of transferee)

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

Dated:                    

Signature

SIGNATURE GUARANTEED:

Signatures must be guaranteed by a participant in the Medallion Signature Guarantee Program at a guarantee level acceptable to the Company’s Rights Agent.

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CERTIFICATE

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

Signature

NOTICE

In the event the certification set forth above in the Form of Assignment is not completed, the Company will deem the Beneficial Owner of the Rights evidenced by the enclosed Rights Certificate to be an Acquiring Person, an Interested Stockholder or an Affiliate or Associate thereof (as each such term is defined in the Rights Agreement) or a transferee of any of the foregoing and accordingly will deem the Rights evidenced by such Rights Certificate to be null and void and not transferable or exercisable. The signature to the foregoing Assignment and Certificate must correspond to the name as written upon the face of this Rights Certificate in every particular, without alteration or enlargement or any change whatsoever.

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FORM OF ELECTION TO PURCHASE

(To be executed if holder desires to exercise

Rights represented by the Right Certificate.)

To Computershare Shareowner Services LLC:

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

Please insert social security

or other identifying number:                     

(Please print name and address)

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

Please insert social security

or other identifying number:                     

(Please print name and address)

Dated:                    

Signature

SIGNATURE GUARANTEED:

Signatures must be guaranteed by a participant in the Medallion Signature Guarantee Program at a guarantee level acceptable to the Company’s Rights Agent.

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CERTIFICATE

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

Signature

NOTICE

In the event the certification set forth above in the Form of Election to Purchase is not completed, the Company will deem the Beneficial Owner of the Rights evidenced by the enclosed Rights Certificate to be an Acquiring Person, an Interested Stockholder or an Affiliate or Associate thereof (as each such term is defined in the Rights Agreement) or a transferee of any of the foregoing and accordingly will deem the Rights evidenced by such Rights Certificate to be null and void and not transferable or exercisable. The signature to the foregoing Assignment and Certificate must correspond to the name as written upon the face of this Rights Certificate in every particular, without alteration or enlargement or any change whatsoever.

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