discretion: (i) delivering to the Purchaser or the Purchaser’s executor a check in the amountof the aggregate Repurchase Price, (ii) canceling an amount of the Purchaser’s indebtedness to theCompany equal to the aggregate Repurchase Price, or (iii) any combination of (i) and (ii) such thatthe combined payment and cancellation of indebtedness equals the aggregate Repurchase Price.          C. ***Rights upon Exercise.***In the event that the Repurchase Option is exercised or deemedexercised, the sole right and remedy of the Purchaser thereafter shall be to receive the RepurchasePrice, and in no case shall the Purchaser have any claim of ownership as to any of the UnreleasedShares.          D. ***Assignability.***The Company in its sole discretion may assign all or part of the RepurchaseOption to one or more employees, officers, directors or stockholders of the Company or otherpersons or organizations.     4. **Release of Shares from Repurchase Option; Vesting.**          A. ***Vesting.***So long as the Purchaser’s continuous status as a Service Provider has not yetterminated in *each*such instance, 25% of the total number of Shares shall be released from theRepurchase Option on the date hereof, and an additional 1/48th of the remaining Shares shall bereleased from the Repurchase Option on the corresponding day of each month thereafter (or if thereis no corresponding day in any such month, on the last day of such month), until all Shares havebeen released on the fourth anniversary of this Agreement.          B. ***Double Trigger Acceleration****.*In the event that the Purchaser’s continuous status as aService Provider is terminated by the Company without Cause (as defined below) within 6 monthsafter a Change of Control (as defined below), 100% of the total number of Shares that have not beenreleased from the Repurchase Option shall be immediately released from the Repurchase Option.          C. ***“Change of Control” Definition.***For purposes of this Agreement, a “***Change of Control***” meanseither:               (1) the acquisition of the Company by another entity by means of any transaction or series ofrelated transactions (including, without limitation, any reorganization, merger or consolidation orstock transfer, but excluding any such transaction effected primarily for the purpose of changingthe domicile of the Company), unless the Company’s stockholders of record immediately prior to suchtransaction or series of related transactions hold, immediately after such transaction or series ofrelated transactions, at least 50% of the voting power of the surviving or acquiring entity; or               (2) a sale of all or substantially all of the assets of the Company.          D. ***“Cause” Definition***. For purposes of this Agreement, “***Cause***” means (i) the Purchaser’sfailure to perform his or her assigned duties or responsibilities as a Service Provider (other thana failure resulting from the Purchaser’s Disability) after notice thereof from the Companydescribing the Purchaser’s failure to perform such duties or responsibilities; (ii) the Purchaserengaging in any act of dishonesty, fraud or misrepresentation; (iii) the Purchaser’s violation ofany federal or state law or regulation applicable to the business of the Company or its affiliates;(iv) the Purchaser’s breach of any confidentiality agreement or invention assignment agreementbetween the Purchaser and the Company (or any affiliate of the Company); or (v) the Purchaser beingconvicted of, or entering a plea of nolo contendere to, any crime or committing any act of moralturpitude.
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          E. ***Delivery of Released Shares.***Subject to the provisions of Section 8, the Shares which havebeen released from the Company’s Repurchase Option shall be delivered to the Purchaser at thePurchaser’s request.     5. **Limitation on Payments.**          A. ***Payments Limitation.***In the event that the severance and other benefits provided for inthis Agreement or otherwise payable to the Purchaser (i) constitute “parachute payments” within themeaning of Section 280G of the Code, and (ii) would be subject to the excise tax imposed by Section4999 of the Code (the “***Excise Tax***”), then the Purchaser’s benefits under this Agreement shall beeither               (1) delivered in full, or               (2) delivered as to such lesser extent which would result in no portion of such benefits beingsubject to the Excise Tax,whichever of the foregoing amounts, taking into account the applicable federal, state and localincome taxes and the Excise Tax, results in the receipt by the Purchaser on an after-tax basis, ofthe greatest amount of benefits, notwithstanding that all or some portion of such benefits may betaxable under Section 4999 of the Code. Any reduction in payments and/or benefits required by thisSection 5 will occur in the following order: (1) reduction of cash payments; (2) reduction ofvesting acceleration of equity awards; and (3) reduction of other benefits paid or provided toPurchaser. In the event that acceleration of vesting of equity awards is to be reduced, suchacceleration of vesting will be cancelled in the reverse order of the date of grant for Purchaser’sequity awards. If two or more equity awards are granted on the same date, each award will bereduced on a *pro-rata*basis. In no event will Purchaser exercise any discretion with respect to theordering of any reductions of payments or benefits under this Section 5.          B. ***Determination.***Unless the Company and the Purchaser otherwise agree in writing, anydetermination required under this Section 5 shall be made in writing by the Company’s independentpublic accountants or a national “Big Four” accounting firm selected by the Company (the“***Accountants***”), whose determination shall be conclusive and binding upon the Purchaser and theCompany for all purposes. For purposes of making the calculations required by this Section 5, theAccountants may make reasonable assumptions and approximations concerning applicable taxes and mayrely on reasonable, good faith interpretations concerning the application of Section 280G and 4999of the Code. The Company and the Purchaser shall furnish to the Accountants such information anddocuments as the Accountants may reasonably request in order to make a determination under thisSection 5. The Company shall bear all costs the Accountants may reasonably incur in connection withany calculations contemplated by this Section 5.     6. **Restrictions on Transfer.**          A. ***Investment Representations and Legend Requirements.***The Purchaser hereby makes theinvestment representations listed on **Exhibit A**to the Company as of the date of this Agreement andas of the date of the Closing, and agrees that such representations are incorporated into thisAgreement by this reference, such that the Company may rely on them in issuing the Shares. ThePurchaser understands and agrees that the Company shall cause the legends set forth below, orsubstantially equivalent legends, to be placed upon any certificate(s) evidencing ownership of theShares,
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together with any other legends that may be required by the Company or by applicable state orfederal securities laws:THE SECURITIES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED UNDER THESECURITIES ACT OF 1933 (THE “***ACT***”) AND MAY NOT BE OFFERED, SOLD OROTHERWISE TRANSFERRED, PLEDGED OR HYPOTHECATED UNLESS AND UNTILREGISTERED UNDER THE ACT OR, IN THE OPINION OF COUNSEL SATISFACTORY TOTHE ISSUER OF THESE SECURITIES, SUCH OFFER, SALE OR TRANSFER, PLEDGE ORHYPOTHECATION OTHERWISE COMPLIES WITH THE ACT.THE SHARES REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO CERTAINRESTRICTIONS ON TRANSFER, A RIGHT OF FIRST REFUSAL, A LOCK-UP PERIOD INTHE EVENT OF A PUBLIC OFFERING AND A REPURCHASE OPTION HELD BYTHE ISSUER OR ITS ASSIGNEE(S) AS SET FORTH IN THE RESTRICTED STOCKPURCHASE AGREEMENT BETWEEN THE ISSUER AND THE ORIGINAL HOLDER OF THESESHARES, A COPY OF WHICH MAY BE OBTAINED AT THE PRINCIPAL OFFICE OF THEISSUER. SUCH TRANSFER RESTRICTIONS, RIGHT OF FIRST REFUSAL, LOCK-UPPERIOD AND REPURCHASE OPTION ARE BINDING ON TRANSFEREES OF THESE SHARES.          B. ***Stop-Transfer Notices*****.**The Purchaser agrees that to ensure compliance with the restrictionsreferred to herein, the Company may issue appropriate “stop transfer” instructions to its transferagent, if any, and that, if the Company transfers its own securities, it may make appropriatenotations to the same effect in its own records.          C. ***Refusal to Transfer*****.**The Company shall not be required (i) to transfer on its books anyShares that have been sold or otherwise transferred in violation of any of the provisions of thisAgreement or (ii) to treat as owner of such Shares or to accord the right to vote or pay dividendsto any purchaser or other transferee to whom such Shares shall have been so transferred.          D. ***Lock-Up Period*****.**The Purchaser hereby agrees that the Purchaser shall not sell, offer,pledge, contract to sell, grant any option or contract to purchase, purchase any option or contractto sell, grant any right or warrant to purchase, lend or otherwise transfer or encumber, directlyor indirectly, any Shares or other securities of the Company, nor shall the Purchaser enter intoany swap, hedging or other arrangement that transfers to another, in whole or in part, any of theeconomic consequences of ownership of any Shares or other securities of the Company, during theperiod from the filing of the first registration statement of the Company filed under theSecurities Act of 1933, as amended (the “***Securities Act***”), that includes securities to be sold onbehalf of the Company to the public in an underwritten public offering under the Securities Actthrough the end of the 180-day period following the effective date of such registration statement(or such other period as may be requested by the Company or the underwriters to accommodateregulatory restrictions on (i) the publication or other distribution of research reports and (ii)analyst recommendations and opinions, including, but not limited to, the restrictions contained inNASD Rule 2711(f)(4) or NYSE Rule 472(f)(4), or any successor provisions or amendments thereto).The Purchaser further agrees, if so requested by the Company or any representative of itsunderwriters, to enter into such underwriter’s standard form of “lockup” or “market standoff”agreement in a form
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satisfactory to the Company and such underwriter. The Company may impose stop-transferinstructions with respect to securities subject to the foregoing restrictions until the end of anysuch restriction period.          E. ***Unreleased Shares*****.**No Unreleased Shares subject to the Repurchase Option contained inSection 3 of this Agreement, nor any beneficial interest in such Shares, shall be sold, gifted,transferred, encumbered or otherwise disposed of in any way (whether by operation of law orotherwise) by the Purchaser, other than as expressly permitted or required by Section 3.          F. ***Released Shares*****.**No Shares purchased pursuant to this Agreement, nor any beneficialinterest in such Shares, shall be sold, transferred, encumbered or otherwise disposed of in any way(whether by operation of law or otherwise) by the Purchaser or any subsequent transferee, otherthan in compliance with the Company’s right of first refusal provisions contained in Section 7 ofthis Agreement.     7. **Company’s Right of First Refusal.**Before any Shares acquired by the Purchaser pursuant tothis Agreement (or any beneficial interest in such Shares) may be sold, transferred, encumbered orotherwise disposed of in any way (whether by operation of law or otherwise) by the Purchaser or anysubsequent transferee (each a “***Holder***”), such Holder must first offer such Shares or beneficialinterest to the Company and/or its assignee(s) as follows:          A. ***Notice of Proposed Transfer*****.**The Holder shall deliver to the Company a written noticestating: (i) the Holder’s bona fide intention to sell or otherwise transfer the Shares; (ii) thename of each proposed transferee; (iii) the number of Shares to be transferred to each proposedtransferee; (iv) the bona fide cash price or other consideration for which the Holder proposes totransfer the Shares; and (v) that by delivering the notice, the Holder offers all such Shares tothe Company and/or its assignee(s) pursuant to this section and on the same terms described in thenotice.          B. ***Exercise of Right of First Refusal*****.**At any time within 30 days after receipt of theHolder’s notice, the Company and/or its assignee(s) may, by giving written notice to the Holder,elect to purchase all, but not less than all, of the Shares proposed to be transferred to any oneor more of the proposed transferees, at the purchase price determined in accordance with Section7.C.          C. ***Purchase Price*****.**The purchase price for the Shares purchased by the Company and/or itsassignee(s) under this section shall be the price listed in the Holder’s notice. If the pricelisted in the Holder’s notice includes consideration other than cash, the cash equivalent value ofthe non-cash consideration shall be determined by the Board of Directors of the Company in its solediscretion.          D. ***Payment*****.**Payment of the purchase price shall be made, at the option of the Company and/orits assignee(s), in cash (by check), by cancellation of all or a portion of any outstandingindebtedness of the Holder to the Company and/or its assignee(s), or by any combination thereofwithin 30 days after receipt by the Company of the Holder’s notice (or at such later date as iscalled for by such notice).          E. ***Holder’s Right to Transfer*****.**If all of the Shares proposed in the notice to be transferredto a given proposed transferee are not purchased by the Company and/or its assignee(s) as providedin this section, then the Holder may sell or otherwise transfer such Shares to that proposedtransferee; *provided that*: (i) the transfer is made only on the terms provided for in the notice,with the exception of the purchase price, which may be either the price listed in the notice or anyhigher price; (ii) such transfer is consummated within 60 days after the date the notice isdelivered to the Company; (iii)
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the transfer is effected in accordance with any applicable securities laws, and if requestedby the Company, the Holder shall have delivered an opinion of counsel acceptable to the Company tothat effect; and (iv) the proposed transferee agrees in writing to receive and hold the Shares sotransferred subject to all of the provisions of this Agreement, including but not limited to thissection, and there shall be no further transfer of such Shares except in accordance with the termsof this section. If any Shares described in a notice are not transferred to the proposed transfereewithin the period provided above, then before any such Shares may be transferred, a new noticeshall be given to the Company, and the Company and/or its assignees shall again be offered theright of first refusal described in this section.          F. ***Exception for Certain Family Transfers*****.**Notwithstanding anything to the contrary containedelsewhere in this section, the transfer of any or all of the Shares during the Holder’s lifetime oron the Holder’s death by will or intestacy to (i) the Holder’s spouse or domestic partner; (ii) theHolder’s lineal descendants or antecedents, siblings, aunts, uncles, cousins, nieces and nephews(including adoptive relationships and step relationships), and their spouses or domestic partners;(iii) the lineal descendants or antecedents, siblings, cousins, aunts, uncles, nieces and nephewsof Holder’s spouse or domestic partner (including adoptive relationships and step relationships),and their spouses or domestic partners; and (iv) a trust or other similar estate planning vehiclefor the benefit of the Holder or any such person, shall be exempt from the provisions of thissection; *provided*that, in each such case, the transferee agrees in writing to receive and hold theShares so transferred subject to all of the provisions of this Agreement, including but not limitedto this section, and there shall be no further transfer of such Shares except in accordance withthe terms of this section; and *provided further*, that without the prior written consent of theCompany, which may be withheld in the sole discretion of the Company, no more than three transfersmay be made pursuant to this section, including all transfers by the Holder and all transfers byany transferee. For purposes of this Agreement, a person will be deemed to be a “***domestic partner***”of another person if the two persons (1) reside in the same residence and plan to do soindefinitely, (2) have resided together for at least one year, (3) are each at least 18 years ofage and mentally competent to consent to contract, (4) are not blood relatives any closer thanwould prohibit legal marriage in the state in which they reside, (5) are financiallyinterdependent, as demonstrated to the reasonable satisfaction of the Company and (6) have eachbeen the sole spouse equivalent of the other for the year prior to the transfer and plan to remainso indefinitely; *provided*that a person will not be considered a domestic partner if he or she ismarried to another person or has any other spouse equivalent.          G. ***Termination of Right of First Refusal*****.**The right of first refusal contained in this sectionshall terminate as to all Shares purchased hereunder upon the earlier of: (i) the closing date ofthe first sale of Common Stock of the Company to the general public pursuant to a registrationstatement filed with and declared effective by the Securities and Exchange Commission under theSecurities Act, and (ii) the closing date of a Change of Control pursuant to which the holders ofthe outstanding voting securities of the Company receive securities of a class registered pursuantto Section 12 of the Securities Exchange Act of 1934, as amended.     8. **Escrow.**          A. ***Deposit.***As security for the faithful performance of this Agreement, the Purchaser agrees,immediately upon receipt of the certificate(s) evidencing the Shares, to deliver suchcertificate(s), together with a stock power in the form of **Exhibit B**attached to this Agreement,executed by the Purchaser and by the Purchaser’s spouse, if any (with the date and number of Sharesleft blank), to the Secretary of the Company or to another designee of the Company (the “***EscrowAgent***”). These documents shall be held by the Escrow Agent pursuant to the Joint EscrowInstructions of the Company
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and the Purchaser set forth in **Exhibit C**attached to this Agreement, which instructions areincorporated into this Agreement by this reference, and which instructions shall also be deliveredto the Escrow Agent after the Closing.          B. ***Rights in Escrow Shares.***Subject to the terms hereof, the Purchaser shall have all therights of a stockholder with respect to such Shares while they are held in escrow, includingwithout limitation, the right to vote the Shares. If, from time to time during the term of theCompany’s Repurchase Option, there is (i) any stock dividend, stock split or other change in theShares, (ii) any dividend of cash or other property on the Shares, or (iii) any merger or sale ofall or substantially all of the assets or other acquisition of the Company, any and all new,substituted or additional securities or cash or other consideration to which the Purchaser isentitled by reason of the Purchaser’s ownership of the Shares shall immediately become subject tothis escrow, deposited with the Escrow Agent and included thereafter as “***Shares***” for purposes ofthis Agreement and the Company’s Repurchase Option.     9. **Tax Consequences.**The Purchaser has reviewed with the Purchaser’s own tax advisors thefederal, state, local and foreign tax consequences of this investment and the transactionscontemplated by this Agreement. The Purchaser is relying solely on such advisors and not on anystatements or representations of the Company or any of its agents. The Purchaser understands thatthe Purchaser (and not the Company) shall be responsible for any tax liability that may arise as aresult of the transactions contemplated by this Agreement. The Purchaser understands that Section83 of the Code, taxes as ordinary income the difference between the purchase price for the Sharesand the fair market value of the Shares as of the date any restrictions on the Shares lapse. Inthis context, “restriction” includes the right of the Company to buy back the Shares pursuant tothe Repurchase Option. The Purchaser understands that the Purchaser may elect to be taxed at thetime the Shares are purchased rather than when and as the Repurchase Option expires by filing anelection under Section 83(b) of the Code with the IRS within 30 days from the date of purchase. **THEFORM FOR MAKING THIS SECTION 83(B) ELECTION IS ATTACHED TO THIS AGREEMENT AS*****EXHIBIT D*****AND THEPURCHASER (AND NOT THE COMPANY OR ANY OF ITS AGENTS) SHALL BE SOLELY RESPONSIBLE FOR APPROPRIATELYFILING SUCH FORM, EVEN IF THE PURCHASER REQUESTS THE COMPANY OR ITS AGENTS TO MAKE THIS FILING ONTHE PURCHASER’S BEHALF.**     10. **General Provisions.**          A. ***Choice of Law*****.**This Agreement shall be governed by the internal substantive laws, but notthe choice of law rules, of Colorado          B. ***Integration*****.**This Agreement, including all exhibits hereto, represents the entire agreementbetween the parties with respect to the purchase of the Shares by the Purchaser and supersedes andreplaces any and all prior written or oral agreements regarding the subject matter of thisAgreement including, but not limited to, any representations made during any interviews, relocationdiscussions or negotiations whether written or oral.          C. ***Notices*****.**Any notice, demand, offer, request or other communication required or permitted tobe given by either the Company or the Purchaser pursuant to the terms of this Agreement shall be inwriting and shall be deemed effectively given the earlier of (i) when received, (ii) when deliveredpersonally, (iii) one business day after being delivered by facsimile (with receipt of appropriateconfirmation), (iv) one business day after being deposited with an overnight courier service or (v)four days after being deposited in the U.S. mail, First Class with postage prepaid and returnreceipt requested, and addressed to the parties at the addresses provided to the Company (which theCompany agrees to
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disclose to the other parties upon request) or such other address as a party may request bynotifying the other in writing.          D. ***Successors*****.**Any successor to the Company (whether direct or indirect and whether bypurchase, merger, consolidation, liquidation or otherwise) to all or substantially all of theCompany’s business and/or assets shall assume the obligations under this Agreement and agreeexpressly to perform the obligations under this Agreement in the same manner and to the same extentas the Company would be required to perform such obligations in the absence of a succession. Forall purposes under this Agreement, the term “Company” shall include any successor to the Company’sbusiness and/or assets which executes and delivers the assumption agreement described in thissection or which becomes bound by the terms of this Agreement by operation of law. Subject to therestrictions on transfer set forth in this Agreement, this Agreement shall be binding upon thePurchaser and his or her heirs, executors, administrators, successors and assigns.          E. ***Assignment; Transfers.***Except as set forth in this Agreement, this Agreement, and any andall rights, duties and obligations hereunder, shall not be assigned, transferred, delegated orsublicensed by the Purchaser without the prior written consent of the Company. Any attempt by thePurchaser without such consent to assign, transfer, delegate or sublicense any rights, duties orobligations that arise under this Agreement shall be void. Except as set forth in this Agreement,any transfers in violation of any restriction upon transfer contained in any section of thisAgreement shall be void, unless such restriction is waived in accordance with the terms of thisAgreement.          F. ***Waiver*****.**Either party’s failure to enforce any provision of this Agreement shall not in anyway be construed as a waiver of any such provision, nor prevent that party from thereafterenforcing any other provision of this Agreement. The rights granted both parties hereunder arecumulative and shall not constitute a waiver of either party’s right to assert any other legalremedy available to it.          G. ***Purchaser Investment Representations and Further Documents*****.**The Purchaser agrees uponrequest to execute any further documents or instruments necessary or reasonably desirable in theview of the Company to carry out the purposes or intent of this Agreement, including (but notlimited to) the applicable exhibits and attachments to this Agreement.          H. ***Severability*****.**Should any provision of this Agreement be found to be illegal orunenforceable, the other provisions shall nevertheless remain effective and shall remainenforceable to the greatest extent permitted by law.          I. ***Rights as Stockholder*****.**Subject to the terms and conditions of this Agreement, the Purchasershall have all of the rights of a stockholder of the Company with respect to the Shares from andafter the date that the Purchaser delivers a fully executed copy of this Agreement (including theapplicable exhibits and attachments to this Agreement) and full payment for the Shares to theCompany, and until such time as the Purchaser disposes of the Shares in accordance with thisAgreement. Upon such transfer, the Purchaser shall have no further rights as a holder of the Sharesso purchased except (in the case of a transfer to the Company) the right to receive payment for theShares so purchased in accordance with the provisions of this Agreement, and the Purchaser shallforthwith cause the certificate(s) evidencing the Shares so purchased to be surrendered to theCompany for transfer or cancellation.          J. ***Adjustment for Stock Split.***All references to the number of Shares and the purchase priceof the Shares in this Agreement shall be adjusted to reflect any stock split, stock dividend orother change in the Shares which may be made after the date of this Agreement.
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          K. ***Employment at Will*****.**THE PURCHASER ACKNOWLEDGES AND AGREES THAT THE VESTING OF SHARESPURSUANT TO THIS AGREEMENT IS EARNED ONLY BY CONTINUING SERVICE AS A SERVICE PROVIDER AT WILL (ANDNOT THROUGH THE ACT OF BEING HIRED OR PURCHASING SHARES HEREUNDER). THE PURCHASER FURTHERACKNOWLEDGES AND AGREES THAT THIS AGREEMENT, THE TRANSACTIONS CONTEMPLATED HEREUNDER AND THEVESTING SCHEDULE SET FORTH HEREIN DO NOT CONSTITUTE AN EXPRESS OR IMPLIED PROMISE OF CONTINUEDENGAGEMENT AS A SERVICE PROVIDER FOR THE VESTING PERIOD, OR FOR ANY PERIOD AT ALL, AND SHALL NOTINTERFERE WITH THE PURCHASER’S RIGHT OR THE COMPANY’S RIGHT TO TERMINATE THE PURCHASER’SRELATIONSHIP WITH THE COMPANY AT ANY TIME, WITH OR WITHOUT CAUSE OR NOTICE.          L. ***Arbitration and Equitable Relief.***               (1) *Arbitration.*IN CONSIDERATION OF THE PROMISES IN THIS AGREEMENT, THE PURCHASER AGREES THATANY AND ALL CONTROVERSIES, CLAIMS, OR DISPUTES WITH ANYONE (INCLUDING THE COMPANY AND ANY EMPLOYEE,OFFICER, DIRECTOR, SHAREHOLDER OR BENEFIT PLAN OF THE COMPANY IN THEIR CAPACITY AS SUCH OROTHERWISE) ARISING OUT OF, RELATING TO, OR RESULTING FROM THIS AGREEMENT, SHALL BE SUBJECT TOBINDING ARBITRATION UNDER COLORADO LAW. DISPUTES WHICH THE PURCHASER AGREES TO ARBITRATE, ANDTHEREBY AGREES TO WAIVE ANY RIGHT TO A TRIAL BY JURY, INCLUDE ANY STATUTORY CLAIMS UNDER STATE ORFEDERAL LAW, INCLUDING, BUT NOT LIMITED TO, CLAIMS UNDER TITLE VII OF THE CIVIL RIGHTS ACT OF 1964,THE AMERICANS WITH DISABILITIES ACT OF 1990, THE AGE DISCRIMINATION IN EMPLOYMENT ACT OF 1967, THEOLDER WORKERS BENEFIT PROTECTION ACT, THE WORKER ADJUSTMENT AND RETRAINING NOTIFICATION ACT, THELAWS OF COLORADO, CLAIMS OF HARASSMENT, DISCRIMINATION OR WRONGFUL TERMINATION AND ANY STATUTORYCLAIMS. THE PURCHASER FURTHER UNDERSTANDS THAT THIS AGREEMENT TO ARBITRATE ALSO APPLIES TO ANYDISPUTES THAT THE COMPANY MAY HAVE WITH THE PURCHASER.               (2) *Procedure.*THE PURCHASER AGREES THAT ANY ARBITRATION WILL BE ADMINISTERED BY THE AMERICANARBITRATION ASSOCIATION (“***AAA***”) AND THAT THE NEUTRAL ARBITRATOR WILL BE SELECTED IN A MANNERCONSISTENT WITH ITS NATIONAL RULES FOR THE RESOLUTION OF EMPLOYMENT DISPUTES. THE PURCHASER AGREESTHAT THE ARBITRATOR SHALL HAVE THE POWER TO DECIDE ANY MOTIONS BROUGHT BY ANY PARTY TO THEARBITRATION, INCLUDING MOTIONS FOR SUMMARY JUDGMENT AND/OR ADJUDICATION AND MOTIONS TO DISMISS ANDDEMURRERS, PRIOR TO ANY ARBITRATION HEARING. THE PURCHASER ALSO AGREES THAT THE ARBITRATOR SHALLHAVE THE POWER TO AWARD ANY REMEDIES, INCLUDING ATTORNEYS’ FEES AND COSTS, AVAILABLE UNDERAPPLICABLE LAW. PURCHASER UNDERSTANDS THAT THE COMPANY WILL PAY FOR ANY ADMINISTRATIVE OR HEARINGFEES CHARGED BY THE ARBITRATOR OR AAA EXCEPT THAT PURCHASER SHALL PAY THE FIRST $125.00 OF ANYFILING FEES ASSOCIATED WITH ANY ARBITRATION PURCHASER INITIATES. PURCHASER AGREES THAT THEARBITRATOR SHALL ADMINISTER AND CONDUCT ANY ARBITRATION IN A MANNER CONSISTENT WITH THE LAWS OFCOLORADO AND THAT TO THE EXTENT THAT THE AAA’S NATIONAL RULES FOR THE RESOLUTION OF EMPLOYMENTDISPUTES CONFLICT WITH THE LAWS OF
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COLORADO, THE RULES SHALL TAKE PRECEDENCE. THE PURCHASER AGREES THAT THE DECISION OF THEARBITRATOR SHALL BE IN WRITING.               (3) *Remedy.*EXCEPT AS PROVIDED BY THE LAWS OF COLORADO AND THIS AGREEMENT, ARBITRATION SHALLBE THE SOLE, EXCLUSIVE AND FINAL REMEDY FOR ANY DISPUTE BETWEEN THE PURCHASER AND THE COMPANY.ACCORDINGLY, EXCEPT AS PROVIDED FOR BY THE LAWS OF COLORADO AND THIS AGREEMENT, NEITHER THEPURCHASER NOR THE COMPANY WILL BE PERMITTED TO PURSUE COURT ACTION REGARDING CLAIMS THAT ARESUBJECT TO ARBITRATION. NOTWITHSTANDING, THE ARBITRATOR WILL NOT HAVE THE AUTHORITY TO DISREGARD ORREFUSE TO ENFORCE ANY LAWFUL COMPANY POLICY, AND THE ARBITRATOR SHALL NOT ORDER OR REQUIRE THECOMPANY TO ADOPT A POLICY NOT OTHERWISE REQUIRED BY LAW WHICH THE COMPANY HAS NOT ADOPTED.               (4) *Availability of Injunctive Relief.*BOTH PARTIES AGREE THAT ANY PARTY MAY PETITION A COURTFOR INJUNCTIVE RELIEF AS PERMITTED BY THE LAWS OF COLORADO INCLUDING, BUT NOT LIMITED TO, WHEREEITHER PARTY ALLEGES OR CLAIMS A VIOLATION OF ANY CONFIDENTIAL INFORMATION OR INVENTION ASSIGNMENTAGREEMENT BETWEEN THE PURCHASER AND THE COMPANY OR ANY OTHER AGREEMENT REGARDING TRADE SECRETS,CONFIDENTIAL INFORMATION, NONSOLICITATION OR LABOR CODE §2870. BOTH PARTIES UNDERSTAND THAT ANYBREACH OR THREATENED BREACH OF SUCH AN AGREEMENT WILL CAUSE IRREPARABLE INJURY AND THAT MONEYDAMAGES WILL NOT PROVIDE AN ADEQUATE REMEDY THEREFOR AND BOTH PARTIES HEREBY CONSENT TO THEISSUANCE OF AN INJUNCTION. IN THE EVENT EITHER PARTY SEEKS INJUNCTIVE RELIEF, THE PREVAILING PARTYSHALL BE ENTITLED TO RECOVER REASONABLE COSTS AND ATTORNEYS’ FEES.               (5) *Administrative Relief.*THE PURCHASER UNDERSTANDS THAT THIS AGREEMENT DOES NOT PROHIBIT THEPURCHASER FROM PURSUING AN ADMINISTRATIVE CLAIM WITH A LOCAL, STATE OR FEDERAL ADMINISTRATIVE BODYSUCH AS THE DEPARTMENT OF FAIR EMPLOYMENT AND HOUSING, THE EQUAL EMPLOYMENT OPPORTUNITY COMMISSIONOR THE WORKERS’ COMPENSATION BOARD. THIS AGREEMENT DOES, HOWEVER, PRECLUDE THE PURCHASER FROMPURSUING COURT ACTION REGARDING ANY SUCH CLAIM.               (6) *Voluntary Nature of Agreement.*THE PURCHASER ACKNOWLEDGES AND AGREES THAT THE PURCHASER ISEXECUTING THIS AGREEMENT VOLUNTARILY AND WITHOUT ANY DURESS OR UNDUE INFLUENCE BY THE COMPANY ORANYONE ELSE. THE PURCHASER FURTHER ACKNOWLEDGES AND AGREES THAT THE PURCHASER HAS CAREFULLY READTHIS AGREEMENT AND THAT THE PURCHASER HAS ASKED ANY QUESTIONS NEEDED FOR THE PURCHASER TOUNDERSTAND THE TERMS, CONSEQUENCES AND BINDING EFFECT OF THIS AGREEMENT AND FULLY UNDERSTANDS IT,INCLUDING THAT ***THE PURCHASER IS WAIVING THE PURCHASER’S RIGHT TO A JURY TRIAL***. FINALLY, THEPURCHASER AGREES THAT THE PURCHASER HAS BEEN PROVIDED AN OPPORTUNITY TO SEEK THE ADVICE OF ANATTORNEY OF THE PURCHASER’S CHOICE BEFORE SIGNING THIS AGREEMENT.          M. ***Reliance on Counsel and Advisors.***The Purchaser acknowledges that Willkie Farr & GallagherLLP is representing only the Company in this transaction. The Purchaser acknowledges
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that he or she has had the opportunity to review this Agreement, including all attachmentshereto, and the transactions contemplated by this Agreement with his or her own legal counsel, taxadvisors and other advisors. The Purchaser is relying solely on his or her own counsel and advisorsand not on any statements or representations of the Company or its agents for legal or other advicewith respect to this investment or the transactions contemplated by this Agreement.          N. ***Counterparts.***This Agreement may be executed in one or more counterparts, each of whichwill be deemed an original, but all of which together will constitute one and the same agreement.Facsimile copies of signed signature pages shall be binding originals.(*signature page follows*)
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     The parties represent that they have read this Agreement in its entirety, have had anopportunity to obtain the advice of counsel prior to executing this Agreement and fully understandthis Agreement. The Purchaser agrees to notify the Company of any change in his or her addressbelow.   **Erle T. Mast** **CLOVIS ONCOLOGY, INC.**   /s/ Erle T. Mast /s/ Patrick J. Mahaffy   *Signature* *Signature*   Erle T. Mast Patrick J. Mahaffy   *Print Name* *Print Name*     Chief Executive Officer and President     *Print Title*   *Address:*              
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***EXHIBIT A*****INVESTMENT REPRESENTATION STATEMENT**     PURCHASER : Erle T. Mast COMPANY : Clovis Oncology, Inc. SECURITY : Common Stock AMOUNT :  583,334 shares DATE : May __, 2009     In connection with the purchase of the above-listed shares, I, the undersigned purchaser,represent to the Company as follows:     1. ***The Company may rely on these representations*****.**I understand that the Company’s sale of theshares to me has not been registered under the Securities Act of 1933, as amended (the “***SecuritiesAct***”), because the Company believes, relying in part on my representations in this document, thatan exemption from such registration requirement is available for such sale. I understand that theavailability of this exemption depends upon the representations I am making to the Company in thisdocument being true and correct.     2. ***I am purchasing for investment*****.**I am purchasing the shares solely for investment purposes,and not for further distribution. My entire legal and beneficial ownership interest in the sharesis being purchased and shall be held solely for my account, except to the extent I intend to holdthe shares jointly with my spouse. I am not a party to, and do not presently intend to enter into,any contract or other arrangement with any other person or entity involving the resale, transfer,grant of participation with respect to or other distribution of any of the shares. My investmentintent is not limited to my present intention to hold the shares for the minimum capital gainsperiod specified under any applicable tax law, for a deferred sale, for a specified increase ordecrease in the market price of the shares, or for any other fixed period in the future.     3. ***I can protect my own interests*****.**I can properly evaluate the merits and risks of aninvestment in the shares and can protect my own interests in this regard, whether by reason of myown business and financial expertise, the business and financial expertise of certain professionaladvisors unaffiliated with the Company with whom I have consulted, or my preexisting business orpersonal relationship with the Company or any of its officers, directors or controlling persons.     4. ***I am informed about the Company*****.**I am sufficiently aware of the Company’s business affairsand financial condition to reach an informed and knowledgeable decision to acquire the shares. Ihave had opportunity to discuss the plans, operations and financial condition of the Company withits officers, directors or controlling persons, and have received all information I deemappropriate for assessing the risk of an investment in the shares.
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     5. ***I recognize my economic risk*****.**I realize that the purchase of the shares involves a highdegree of risk, and that the Company’s future prospects are uncertain. I am able to hold the sharesindefinitely if required, and am able to bear the loss of my entire investment in the shares.     6. ***I know that the shares are restricted securities*****.**I understand that the shares are“restricted securities” in that the Company’s sale of the shares to me has not been registeredunder the Securities Act in reliance upon an exemption for non-public offerings. In this regard, Ialso understand and agree that:          A. I must hold the shares indefinitely, unless any subsequent proposed resale by me isregistered under the Securities Act, or unless an exemption from registration is otherwiseavailable (such as Rule 144);          B. the Company is under no obligation to register any subsequent proposed resale of the sharesby me; *and*          C. the certificate evidencing the shares will be imprinted with a legend which prohibits thetransfer of the shares unless such transfer is registered or such registration is not required inthe opinion of counsel for the Company.     7. ***I am familiar with Rule 144*****.**I am familiar with Rule 144 adopted under the Securities Act,which in some circumstances permits limited public resales of “restricted securities” like theshares acquired from an issuer in a non-public offering. I understand that my ability to sell theshares under Rule 144 in the future is uncertain, and may depend upon, among other things: (i) theavailability of certain current public information about the Company; (ii) the resale occurringmore than a specified period after my purchase and full payment (within the meaning of Rule 144)for the shares; and (iii) if I am an affiliate of the Company (A) the sale being made in anunsolicited “broker’s transaction”, transactions directly with a market maker or riskless principaltransactions, as those terms are defined under the Securities Exchange Act of 1934, as amended, (B)the amount of shares being sold during any three-month period not exceeding the specifiedlimitations stated in Rule 144, *and*(C) timely filing of a notice of proposed sale on Form 144, ifapplicable.     8. ***I know that Rule 144 may never be available*****.**I understand that the requirements of Rule 144may never be met, and that the shares may never be saleable under the rule. I further understandthat at the time I wish to sell the shares, there may be no public market for the Company’s stockupon which to make such a sale, or the current public information requirements of Rule 144 may notbe satisfied, either of which may preclude me from selling the shares under Rule 144 even if therelevant holding period had been satisfied.     9. ***I know that I am subject to further restrictions on resale*****.**I understand that in the eventRule 144 is not available to me, any future proposed sale of any of the shares by me will not bepossible without prior registration under the Securities Act, compliance with some otherregistration exemption (which may or may not be available), or *each*of the following: (i) mywritten notice to the Company containing detailed information regarding the proposed sale, (ii) myproviding an opinion of my counsel to the effect that such sale will not require registration, and(iii) the Company notifying me in writing that its counsel concurs in such opinion. I understandthat neither the Company nor its counsel is obligated to provide me with any such opinion. Iunderstand that although Rule 144 is not exclusive, the Staff of the SEC has stated that personsproposing to sell private placement securities other than in a registered offering or pursuant toRule 144 will have a substantial burden of proof in establishing that an exemption
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from registration is available for such offers or sales, and that such persons and theirrespective brokers who participate in such transactions do so at their own risk.     10. ***I know that I may have tax liability due to the uncertain value of the shares*****.**Iunderstand that the Board of Directors believes its valuation of the shares represents a fairappraisal of their worth, but that it remains possible that, with the benefit of hindsight, theInternal Revenue Service may successfully assert that the value of the shares on the date of mypurchase is substantially greater than the Board’s appraisal. I understand that any additionalvalue ascribed to the shares by such an IRS determination will constitute ordinary income to me asof the purchase date, and that any additional taxes and interest due as a result will be my soleresponsibility payable only by me, and that the Company need not and will not reimburse me for thattax liability.     11. ***Residence*****.**The address of my principal residence is set forth on the signature page below.     By signing below, I acknowledge my agreement with each of the statements contained in thisInvestment Representation Statement as of the date first set forth above, and my intent for theCompany to rely on such statements in issuing the shares to me.        *Purchaser’s Signature*        *Print Name*   *Address of Purchaser’s principal residence:*              
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***EXHIBIT B*****STOCK POWER AND ASSIGNMENT**