Exhibit 10.51**Stock Option No:**          **EMPLOYEE STOCK OPTION AGREEMENT**     EMPLOYEE STOCK OPTION AGREEMENT, dated as of (this “Agreement”), by and betweenINHIBITEX, INC., a Delaware corporation (the “Company”), and ___(the “Optionee”).**R E C I T A L S :**     WHEREAS, the Company has adopted the Amended and Restated 2004 Stock Incentive Plan (the“Plan”) to provide long-term performance incentives to those employees, contractors and consultantsof the Company and its Subsidiaries who are largely responsible for the management, growth andprotection of the business of the Company and its Subsidiaries; and     WHEREAS, the Company desires to grant to the Optionee an option (the “Option”) to purchase anumber of shares of the common stock, $0.001 par value, of the Company (the “Stock”) pursuant tothe Plan and on the terms and conditions set forth herein.     NOW, THEREFORE, for good and valuable consideration, the receipt and adequacy of which ishereby acknowledged, the Company and the Optionee hereby agree as follows:     Section 1. Grant of Option. The Company hereby grants to the Optionee, pursuant tothe Plan and on the terms and conditions set forth herein, an Option to purchase that number ofshares of Stock and at the exercise price as set forth on Schedule A hereto.     (a) Except as otherwise may be provided in Section 2, the Option hereby granted shall vest ininstallments as provided on Schedule A. Notwithstanding the foregoing, in the event of a Change ofControl, if the Optionee has been employed by the Company:          (i) For less than six (6) months on the date of the Change of Control, the Option shall vestas to that number of whole shares of Stock (rounding down) as is equal to twenty-five percent (25%)of the number of unvested shares subject to the Option.          (ii) For six (6) months or more but less than twelve (12) months, the Option shall vest as tothat number of whole shares of Stock (rounding down) as is equal to fifty percent (50%) of thenumber of unvested shares subject to the Option.          (iii) For twelve (12) months or more but less than twenty-four (24) months, the Option shallvest as to that number of whole shares of Stock (rounding down) as is equal to seventy-five percent(75%) of the number of unvested shares subject to the Option.          (iv) For twenty-four (24) months or more, the Option shall vest as to that number of wholeshares of Stock (rounding down) as is equal to one-hundred percent (100%) of the number of unvestedshares subject to the Option.
 

 
     (b) Any shares of Stock subject to the Option that remain unvested after a Change of Controlshall vest in installments as provided on Schedule A, except that “the number of shares subject tothe Option” shall be the number of shares of Stock subject to the Option that remain unvested afterthe Change of Control, if any.     (c) If so designated on Schedule A hereto, this Option is intended to be an Incentive StockOption within the meaning of Section 422 of the Code.     Section 2. Term of Option. Unless earlier terminated pursuant to the other provisionsherein, the Option hereby granted shall terminate at the close of business on the date ten (10)years from the date of this Agreement (the “Expiration Date”).     (a) In addition, at the close of business on the date the Optionee’s employment with theCompany or any Subsidiary terminates for any reason whatsoever (other than by reason of death,Disability or Retirement), the Option shall terminate as to that number of shares of Stock as towhich the Option is not vested on that date.     (b) If the Optionee’s employment is terminated for Cause, the unexercised portion of theOption will terminate immediately upon the Optionee’s termination of employment.     (c) If the Optionee’s employment with the Company or any Subsidiary terminates for any reasonother than Cause, death, Disability or Retirement, then the Option may be exercised to the extentvested on the date of the Optionee’s termination of employment at any time prior to the earlier ofthe Expiration Date and three (3) months after the date of the Optionee’s termination ofemployment, and any part of the Option which is not so exercised within such period shall thereuponterminate.     (d) If the Optionee’s employment with the Company or any Subsidiary terminates by reason ofhis or her death or Disability, then the vesting of the Option shall accelerate such that theOption may be exercised, as to the entire number of whole shares of Stock that are covered by theOption on the date of the Optionee’s death or Disability, at any time prior to the earlier of theExpiration Date and twelve (12) months after the date of the Optionee’s death or Disability, andany part of the Option which is not so exercised within such period shall thereupon terminate.     (e) If the Optionee’s employment with the Company or any Subsidiary terminates by reason ofhis or her Retirement, then the vesting of the Option shall accelerate such that the Option may beexercised, as to the entire number of whole shares of Stock that are covered by the Option on thedate of the Optionee’s termination of employment, at any time prior to the earlier of theExpiration Date and twenty-four (24) months after the date of the Optionee’s Retirement, and anypart of the Option which is not so exercised within such period shall thereupon terminate.     (f) For all purposes of this Agreement, the Optionee’s employment with the Company or anySubsidiary shall terminate at the time when the employment relationship between the Optionee andthe Company or any Subsidiary is terminated for any reason, which
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time shall be conclusively determined from the records of the Company and its Subsidiaries.No termination of employment shall be deemed to occur (i) when there is a simultaneous reemploymentof an Optionee by the Company or any Subsidiary, (ii) at the discretion of the Committee, when theseverance of employment is temporary or pursuant to a leave of absence granted by the Company, and(iii) at the discretion of the Committee, when the termination is followed by the simultaneousestablishment of a consulting relationship by the Company or a Subsidiary with the Optionee. TheCommittee, in its absolute discretion, shall determine the effect of all matters and questionsrelating to termination of employment, including, but not by way of limitation, the question ofwhether a termination of employment resulted from a discharge for Cause.     (g) For purposes of this Agreement, “Retirement” shall mean the cessation of employment withthe Company after an Optionee has attained age sixty-four (64) and completed five (5) or moreconsecutive years of service with the Company or any Subsidiary.     (h) For purposes of this Agreement, “Disability” shall mean “disability” as defined in anyemployment agreement between the Optionee and the Company or any Subsidiary, or if not definedtherein or if there is no such agreement, as defined in the Company’s long-term disability plan.     Section 3. Manner of Exercise.     (a) To exercise the Option, the Optionee shall provide written notice of such exercise in theform provided in Annex 1 hereto to the Secretary of the Company at the Company’s then principaloffice. The notice shall specify the number of shares of Stock for which the Option is beingexercised and shall be accompanied by a payment to the Company in cash or Stock or any combinationthereof equal to the product of (i) the exercise price and (ii) the number of shares of Stock to bepurchased at that time, plus the amount of the withholding taxes estimated in accordance withSection 6 to be due upon the purchase of such number of shares of Stock, unless the Committee shallhave consented to the making of other arrangements with the Optionee.     (b) Delivery of the notice of exercise shall constitute an irrevocable election to purchasethe Stock specified in the notice, and the date on which the Company receives the noticeaccompanied by payment in full of the exercise price for the Stock covered by the notice and theapplicable withholding taxes shall be the date as of which the Stock so purchased shall be deemedto have been issued.     (c) An Optionee may use other Stock that the Optionee has owned for at least six (6) months aspayment of all or any part of the exercise price, which Stock will be valued at its Fair MarketValue as of the date of exercise.     (d) To exercise the Option upon the Optionee’s death, the persons who acquire the right toexercise the Option must prove to the Committee’s satisfaction that they have duly acquired theOption and that they have paid (or have provided for payment of) any taxes, such as estate,transfer, inheritance or death taxes, payable with respect to the Option or to the Stock to whichit relates.
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     Section 4. Transferability. If the Option hereby granted is designated on Schedule Aas an “Incentive Stock Option,” the Option may only be transferred by will or the laws of descentand distribution and may be exercised during the Optionee’s lifetime only by the Optionee. If thisOption is designated on Schedule A as a “Non-Qualified Stock Option,” the Option may betransferred, without consideration, to immediate family members (i.e., children, grandchildren orspouse) of the Optionee, to trusts for the benefit of immediate family members of the Optionee andto partnerships in which the only partners are immediate family members of the Optionee. Except aspermitted by the preceding sentence, this Option may only be transferred by will or the laws ofdescent and distribution and may be exercised during the Optionee’s lifetime only by the Optionee.     Section 5. [Reserved]     Section 6. Withholding Taxes.     (a) At the time of the exercise of all or any part of this Option, the Optionee shall pay tothe Company (or otherwise make arrangements satisfactory to the Committee for the payment of) theamount of the Federal, state and local and foreign income and employment taxes required, in theCompany’s sole judgment, to be collected or withheld with respect to the exercise of the Option.Such amount shall be paid to the Company in cash or by the surrender of that number of whole sharesof Stock with a Fair Market Value (valued on the date of exercise) as shall be equal to, but doesnot exceed, the minimum statutory amounts required to be collected or withheld by the Company withrespect to the exercise of the Option.     (b) If the Option herein granted is designated as an Incentive Stock Option, then the Optioneeagrees that at the time of any “disqualifying disposition” (as defined in Prop. Treas. Reg. Section1.422A-1(b)(1)) of the Stock acquired upon exercise of this Option on or after January 1, 2003, theOptionee shall pay to the Company (or otherwise make arrangements satisfactory to the Committee forthe payment of) the amount of the Federal, state and local and foreign income and employment taxesrequired, in the Company’s sole judgment, to be collected or withheld with respect to thedisqualifying disposition of the Stock acquired upon exercise of the Option. Such amount shall bepaid to the Company in cash or by the surrender of that number of whole shares of Stock with a FairMarket Value (valued on the date of exercise) as shall be equal to, but does not exceed, theminimum statutory amounts required to be collected or withheld by the Company with respect to theexercise of the Option.     Section 7. Lock-Up Period. The Optionee agrees that, if so requested by the Companyor any representative of the underwriters (the “Managing Underwriter”) in connection with any firmcommitment underwritten public offering of any securities of the Company under the Securities Actof 1933, as amended (the “Securities Act”), the Optionee shall not sell or otherwise transfer anyshares of Stock or other securities of the Company (other than any securities of the Company beingregistered in such offering) or enter into any swap or other arrangement that transfers to another,in whole or in part, any of the economic consequences of ownership of the Stock, without the priorwritten consent of the Company and the Managing Underwriter, commencing on the initial date thatsecurities are offered for sale under such offering and continuing for up to 180 days (the “MarketStandoff Period”) thereafter or such greater period, not to exceed an additional twenty (20) days,in order to permit the underwriters to issue research reports in compliance with NASD Rule2711(f)(4). The Optionee further
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agrees to execute promptly such agreements as may be reasonably requested by the ManagingUnderwriter in connection with such offering that are not inconsistent with this Section and thatare deemed reasonably necessary by such Managing Underwriter to further evidence or to give furthereffect hereto. The Company may impose stop-transfer instructions with respect to securitiessubject to the foregoing restrictions until the end of such Market Standoff Period.     Section 8. Rights in Stock Before Issuance and Delivery. No person shall be entitledto become a stockholder of the Company, unless and until such Stock has been issued (or deemed tohave been issued) to such person as fully paid Stock.     Section 9. No Right to Employment. Nothing contained herein shall be construed toconfer on the Optionee any right to continue as an employee of the Company or to derogate from anyright of the Company to retire, request the resignation of or discharge the Optionee, or to lay offor require a leave of absence of the Optionee, with or without pay, at any time, with or withoutCause.     Section 10. Qualifications to Exercise. Anything in this Agreement to the contrarynotwithstanding, in no event may the Option be exercisable if the Company shall, at any time and inits sole discretion, determine that (a) the listing, registration or qualification of any shares ofStock otherwise deliverable upon such exercise, upon any securities exchange or under any state orfederal law, or (b) the consent or approval of any regulatory body, is necessary or desirable inconnection with such exercise. In such event, such exercise shall be held in abeyance and shallnot be effective unless and until such listing, registration, qualification or approval shall havebeen effected or obtained free of any conditions not acceptable to the Company.     Section 11. Conditions to Transfer. Unless the issuance of the shares of Stock uponthe exercise of the Option has been registered under the Securities Act, the Committee may requireas a condition to the right to exercise the Option hereunder that the Company receive from theperson exercising the Option representations, warranties and agreements, at the time of any suchexercise, to the effect that the shares of Stock are being purchased for investment only andwithout any present intention to sell or otherwise distribute such shares of Stock and that suchshares of Stock will not be disposed of in transactions which, in the opinion of counsel to theCompany, would violate the registration provisions of the Securities Act and the rules andregulations thereunder. The certificate issued to evidence such shares of Stock shall bearappropriate legends summarizing these restrictions on the disposition thereof.     Section 12. Entire Agreement. This Agreement and the Plan contain the entireagreement between the parties hereto with respect to the matters contemplated herein and supersedeall prior agreements or understandings among the parties related to such matters.     Section 13. Binding Effect. Subject to the restrictions on transfer herein set forth,this Agreement shall be binding upon and inure to the benefit of the Company and its successors andassigns and upon the Optionee and his or her assigns, heirs, executors, administrators and legalrepresentatives.     Section 14. Amendment or Modification; Waiver. This Agreement may be amended,modified, superseded, canceled, renewed or extended, and the terms or covenants
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hereof may be waived, only by a written instrument executed on behalf of the Company (asauthorized by the Committee) and the Optionee.     Section 15. Governing Law. This Agreement shall be construed and enforced inaccordance with the laws of the State of Delaware, without giving effect to the principles ofconflicts of law thereof.     Section 16. Defined Terms. Capitalized terms used in this Agreement and not otherwisedefined herein have the meaning ascribed to them in the Plan.     Section 17. The Plan. The Optionee acknowledges having received a copy of the Plan.The Option herein granted is subject to all of the terms and provisions of the Plan, all of whichare hereby incorporated herein by reference. In the event of any inconsistency between theprovisions of this Agreement and the provisions of the Plan, the provisions of the Plan shallgovern.     IN WITNESS WHEREOF, the parties hereto have executed this Agreement as of the date first setforth above.      **INHIBITEX, INC.**