**Exhibit 10.1**

** **

**OPTIMER PHARMACEUTICALS, INC.**

 

**AMENDED AND RESTATED SEVERANCE BENEFIT PLAN**

 

**Section 1.****             ****INTRODUCTION.**

 

TheOptimer Pharmaceuticals, Inc. Amendedand Restated Severance Benefit Plan (the “***Plan***”)was established effective May 5, 2010 (the “***EffectiveDate***”) and amends and restates in its entirety the OptimerPharmaceuticals, Inc. Severance Benefit Plan established effectiveOctober 2, 2008 (the “***Prior Plan***”).  The purpose of the Plan is to provide for thepayment of severance benefits to certain eligible employees of OptimerPharmaceuticals, Inc. (the “***Company***”) whose employment with the Company is terminated in a coveredtermination and who meet the eligibility criteria set forth in Section 2(a)below.  This document constitutes thewritten instrument under which the Plan is maintained and supersedes any priorplan or practice of the Company or any written agreement between the Companyand any employee that provides for payments or benefits in the event oftermination of employment or a change in control of the Company, including butnot limited to the Prior Plan, except to the extent such written agreementexpressly contemplates that such persons are eligible to receive benefitsadditional to or in lieu of those provided under the Plan.  This Plan document also is the Summary PlanDescription for the Plan.

 

**Section 2.****             ****ELIGIBILITYFOR BENEFITS.**

 

**(a)****          ****GeneralRules.**  Subject to the requirements setforth in this Section, the Company will grant severance benefits under the Planto Eligible Employees.

 

**(1)****          ****Definitionof “Eligible Employee.”** Forpurposes of this Plan, an Eligible Employee is a full-time or a part-timeregular hire employee of the Company who is notified by the Company in writingthat he or she is eligible for participation in the Plan and (i) whoseemployment is terminated in a Covered Termination (as defined further inSection 2(c) below) provided that the employee has been continuously employedby the Company for at least one hundred eighty (180) days; or (ii) who isselected by the Plan Administrator in its sole discretion to receive thebenefits set forth herein.  Thedetermination of whether an employee is an Eligible Employee shall be made bythe Company, in its sole discretion, and such determination shall be bindingand conclusive on all persons.  Forpurposes of this Plan, part-time employees are those regular hire employees whoare regularly scheduled to work more than twenty (20) hours per week but lessthan a full-time work schedule.  Regularhire employees working twenty (20) hours per week or less and temporaryemployees are not eligible for severance benefits under the Plan.

 

**(2)****          **In order to beeligible to receive any benefits under the Plan, an Eligible Employee who isterminated in a Covered Termination must remain on the job until his or herdate of termination as scheduled by the Company, which may not exceed thirty(30) days from the date of any notification of termination.

 

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**(3)****          **In order to beeligible to receive any benefits under the Plan, an Eligible Employee also mustexecute a general waiver and release in substantially the form attached heretoas Exhibit A, Exhibit B or Exhibit C, as appropriate, and such release mustbecome effective in accordance with its terms. The Company, in its discretion, may modify the form of the requiredrelease to comply with applicable law and shall determine the form of therequired release, which may be incorporated into a termination agreement orother agreement with the Eligible Employee.

 

**(b)****          ****Exceptionsto Benefit Entitlement.**  Anemployee, including an employee who otherwise is an Eligible Employee, will notreceive benefits under the Plan (or will receive reduced benefits under thePlan) in the following circumstances, as determined by the Company in its solediscretion:

 

**(1)****          **The employeehas executed an individually negotiated employment contract or agreement withthe Company relating to severance benefits that is in effect on his or hertermination date, in which case such employee’s severance benefit, if any,shall be governed by the terms of such individually negotiated employmentcontract or agreement and shall be governed by this Plan only to the extentthat the reduction pursuant to Section 3(c) below does not entirely eliminatebenefits under this Plan.

 

**(2)****          **The employeevoluntarily terminates employment with the Company for any reason notconstituting a Constructive Termination. Voluntary terminations include, but are not limited to, resignation,retirement or failure to return from a leave of absence on the scheduled date.

 

**(3)****          **The employee isoffered an identical or substantially equivalent or comparable position withthe Company or an affiliate of the Company. For purposes of the foregoing, a “substantially equivalent or comparableposition” is one that offers the employee substantially the same level ofresponsibility and compensation and does not require a relocation of theemployee’s place of employment by more than thirty (30) miles from its previouslocation.

 

**(4)****          **The employee isoffered immediate reemployment by a successor to the Company or an affiliate of the Company or by apurchaser of its assets, as the case may be, following a change in ownership ofthe Company or a sale of substantially all of the assets of a division orbusiness unit of the Company.  Forpurposes of the foregoing, “immediate reemployment” means that the employee’semployment with the successor to the Company or an affiliate of the Company or the purchaser of its assets, asthe case may be, results in uninterrupted employment such that the employeedoes not incur a lapse in pay as a result of the change in ownership of theCompany or the sale of its assets.

 

**(5)****          **The employee isrehired by the Company or an affiliate of the Company prior to the datebenefits under the Plan are scheduled to commence.

 

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**(6)****          **The employeedoes not confirm in writing that he or she is and shall remain subject to theCompany’s Proprietary Information and Inventions Agreement, including thefailure to sign a termination statement under such Agreement.

 

**(7)****          **Followingnotification of involuntary termination by the Company, the employee does notsatisfactorily perform his or her assigned job duties until the date set by theCompany for the termination of employment.

 

**(8)****          **The employeeterminates employment due to the employee’s death or Disability.

 

**(c)****          ****Definitions:** For purposes of this Plan, thefollowing terms shall have the meanings set forth below:

 

**(1)****          **“***Base Salary***” means the EligibleEmployee’s base pay (excluding incentive pay, premium pay, commissions,overtime, bonuses and other forms of variable compensation), at the rate ineffect during the last regularly scheduled payroll period immediately precedingthe Eligible Employee’s termination date. For any Eligible Employees that are regular part-time employees, “BaseSalary” shall mean the pro-rata equivalent of the Eligible Employee’s base paywhich reflects the part-time status of the Eligible Employee.

 

**(2)****          **“***Cause***” for termination of employmentmeans a termination resulting from the occurrence of any of the followingevents that has a material negative impact on the business or reputation of theCompany:

 

**(i)****           **the employee’s attemptedcommission of, or participation in, a fraud or act of dishonesty against theCompany;

 

**(ii)****          **the employee’s intentional,material violation of any contract or agreement between the employee and theCompany or of any statutory duty owed to the Company;

 

**(iii)****        **the employee’s unauthorizeduse or disclosure of the Company’s confidential information or trade secrets;

 

**(iv)****         **an employee’s intentionalrefusal or intentional failure to act in accordance with any lawful and properdirection or order of his or her superiors;

 

**(v)****          **an employee’s habitual neglectof the duties of employment;

 

**(vi)****         **an employee’s indictment,charge, or conviction of a felony or any crime involving moral turpitude, orparticipation in any act of theft or dishonesty; or

 

**(vii)****       **the employee’s grossmisconduct.

 

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**(3)****          **“***Change of Control***” means any of thefollowing events:

 

**(i)****           **a sale, lease or dispositionof all or substantially all of the assets of the Company; or;

 

**(ii)****          **a merger or consolidation(in a single transaction or a series of related transactions) of the Companywith or into any other corporation or corporations or other entity, or anyother corporate reorganization, where the stockholders of the Corporationimmediately prior to such event do not retain more than fifty percent (50%) ofthe voting power of and interest in the successor entity (excluding anytransactions if the primary purpose of the transaction is to obtain financingfrom new or existing investors).

 

TheBoard shall have the right to determine whether a Change of Control hasoccurred in accordance with the foregoing definition, and its determinationshall be final, binding and conclusive on all persons.

 

**(4)****          **“***Constructive Termination***” means theoccurrence of one or more of the following events, provided that the EligibleEmployee has first provided written notice to the Company within 90 days of thefirst such occurrence of such condition specifying the event(s) constitutingConstructive Termination and specifying that the Eligible Employee intends toterminate employment not earlier than 30 days after providing such notice, andthe Company (or surviving corporation) has not cured such event(s) within 30days (or such longer period as may be specified by the Eligible Employee insuch notice) after such written notice is received by the Company (the “***Cure Period***”), and the EligibleEmployee resigns within 30 days following the end of the Cure Period:

 

**(i)****           **a material diminution in theEligible Employee’s authority, duties or responsibilities; or

 

**(ii)****          **the relocation by theCompany of the principle place for the rendering of the Eligible Employee’sservices hereunder to a location that requires a one-way increase in theEligible Employee’s driving distance of more than 45 miles; or

 

**(iii)****        **a material reduction by the Companyof annual base compensation, which reduction is not applicable to all of theCompany’s senior executive employees.

 

However,none of the foregoing will constitute a Constructive Termination to the extentmutually agreed upon in advance of the occurrence thereof by the EligibleEmployee.

 

**(5)****          **“***Covered Termination***” means (i) aninvoluntary termination of an employee’s employment by the Company other thanfor Cause or (ii) a Constructive Termination by an Eligible Employee who is theCEO or a Company Officer.  A CoveredTermination does not include a termination of employment resulting from suchEligible Employee’s resignation for any reason not constituting a ConstructiveTermination, or due to the Eligible Employee’s death or Disability.

 

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**(6)****          *****“Disability”***means the employee is prevented from performing his duties hereunder byreason of any physical or mental incapacity that results in the employee’ssatisfaction of all requirements necessary to receive benefits under theCompany’s long-term disability plan due to a total disability.  If the Company has no long-term disabilityplan in place, “Disability” shall mean a physical or mental disability orinfirmity of the employee, as determined by a physician of recognized standingselected by the Company, that prevents (or, in the opinion of such physician,is reasonably expected to prevent) the normal performance of his duties as anemployee of the Company for any continuous period of 180 days, or for 180 daysduring any one 12-month period.

 

**(7)****          **“***Equity Award***” means any stockoption, restricted stock, restricted stock unit, or other equity award toacquire shares of the Company’s stock. Notwithstanding the foregoing, for all purposes of the Plan “Equity Award”does not include any equity award issued under or held in any plan that isintended to be qualified under Section 401(a) of the Internal Revenue Code.

 

**(8)****          **“***Non-Performance Vesting Equity Award”***means at any given time an Equity Award that is not a Performance VestingEquity Award.

 

**(9)****          **“***Performance Vesting Equity Award***”means at any given time an Equity Award listed on Appendix C hereto (as may beamended from time to time by the Company) for which the vesting commencement issubject to the attainment of performance goals that have not been attained atsuch time so that the vesting commencement date for such Equity Award has notyet occurred.

 

**(10)****        ****“*Year of Service*”** means each complete year ofemployment in which an Eligible Employee has been employed by the Company.  For purposes of this definition, a year ofemployment shall be a 365 day period (or 366 day period in case of a leap year)that, for the first year of employment, commences on the Eligible Employee’sdate of hire and that, for any subsequent year, commences on an anniversary ofthat hire date.  A Year of Service shallinclude any leave of absence period that was approved by the Company.

 

**Section 3.****             ****AMOUNTOF BENEFIT.**

 

**(a)****          ****SeveranceBenefits.**  Subject tothe exceptions set forth in Section 2(b), Severance benefits under the Plan, ifany, shall be provided to Eligible Employees described in Section 2(a) asfollows:

 

**(i)****           **Eligible Employees that haveless than one Year of Service at the time of the Covered Termination shallreceive the severance benefits described on Appendix A attached hereto.

 

**(ii)****          **Eligible Employees that haveone or more Years of Service at the time of the Covered Termination shallreceive the severance benefits described on Appendix B attached hereto.

 

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**(iii)****        **Severance benefits shall beprovided to an Eligible Employee either under Appendix A or Appendix B, asapplicable, but not both.

 

**(b)****          ****AdditionalBenefits. **Notwithstandingthe foregoing, the Company may, in its sole discretion, provide benefits inaddition to those benefits set forth in Section 3(a) to Eligible Employees andthe provision of any such benefits to an Eligible Employee shall in no wayobligate the Company to provide such benefits to any other Eligible Employee orto any other employee, even if similarly situated.

 

**(c)****          ****CertainReductions. **The Company, inits sole discretion, shall have the authority to reduce an Eligible Employee’sseverance benefits, in whole or in part, by any other severance benefits, payin lieu of notice, or other similar benefits payable to the Eligible Employeeby the Company or an affiliate of the Company that become payable in connectionwith the Eligible Employee’s termination of employment pursuant to (i) anyapplicable legal requirement, including, without limitation, the WorkerAdjustment and Retraining Notification Act, the California Plant Closing Act,or any other similar state law, (ii) a written employment or severanceagreement with the Company, or (iii) any Company policy or practice providingfor the Eligible Employee to remain on the payroll for a limited period of timeafter being given notice of the termination of the Eligible Employee’semployment, and the Plan Administrator shall so construe and implement theterms of the Plan; provided, however, that notwithstanding the foregoing andany other provision in the Plan to the contrary, such reductions shall in noevent reduce the cash severance benefits provided under this Plan to less thantwo (2) weeks of Base Salary.  The Company’sdecision to apply such reductions to the severance benefits of one EligibleEmployee and the amount of such reductions shall in no way obligate the Companyto apply the same reductions in the same amounts to the severance benefits ofany other Eligible Employee, even if similarly situated.  In the Company’s sole discretion, suchreductions may be applied on a retroactive basis, with severance benefitspreviously paid being re-characterized as payments pursuant to the Company’sstatutory obligation.

 

**(d)****          ****Non-Duplicationof Benefits.**  No EligibleEmployee is eligible to receive benefits under this Plan more than one time.

 

**(e)****          ****Terminationof Benefits.**  With respectto each Eligible Employee, benefits under this Plan shall terminate immediatelyif such Eligible Employee, at any time, violates any material proprietaryinformation, non-disparagement, confidentiality or non-solicitation obligationto the Company.

 

**(f)****           ****VestingAcceleration of Equity Awards.**In order to give effect toany acceleration of vesting of Equity Awards to which an Eligible Employee maybe entitled under this Plan, notwithstanding anything to the contrary set forthin the Eligible Employee’s Equity Award agreements or the Company’s equityplans regarding immediate forfeiture of unvested shares upon termination orservice, following an Eligible Employee’s Covered Termination, the sharessubject to any unvested portion of such Eligible Employee’s Equity Awards shallnot be forfeited or returned to the applicable

 

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equityplan before any vesting acceleration of such Equity Awards provided by thisPlan is finally determined and given effect, if applicable; provided, however,that nothing in this Section 3(f) prohibits the Company or a successororganization (or its parent) from causing such Equity Awards to earlierterminate pursuant to the terms of the applicable equity plan or awardagreements in connection with a Change of Control, merger, acquisition or othersimilar corporate transaction where such Equity Awards will terminate and notbe assumed by the successor or acquiring entity.

 

**Section 4.****             ****SECTION409A COMPLIANCE.**

 

**(a)****          **Notwithstandinganything to the contrary set forth herein, any payments and benefits providedunder the Plan (the “***Severance Benefits***”)that constitute “deferred compensation” within the meaning of Section 409A ofthe Internal Revenue Code of 1986, as amended (the “***Code***”) and the regulations and other guidance thereunderand any state law of similar effect (collectively “***Section409A***”) shall not commence in connection with an EligibleEmployee’s termination of employment unless and until the Eligible Employee hasalso incurred a “separation from service” (as such term is defined in TreasuryRegulation Section 1.409A-1(h) (“***Separation From Service***”),unless the Company reasonably determines that such amounts may be provided tothe Eligible Employee without causing the Eligible Employee to incur theadditional 20% tax under Section 409A.

 

**(b)****          **It is intendedthat each installment of the Severance Benefits payments provided for in thisPlan is a separate “payment” for purposes of Treasury Regulation Section1.409A-2(b)(2)(i).  For the avoidance ofdoubt, it is intended that payments of the Severance Benefits set forth in thisPlan satisfy, to the greatest extent possible, the exemptions from theapplication of Section 409A provided under Treasury Regulation Sections1.409A-1(b)(4), 1.409A-1(b)(5) and 1.409A-1(b)(9).  However, if the Company (or, if applicable,the successor entity thereto) determines that the Severance Benefits constitute“deferred compensation” under Section 409A and the Eligible Employee is, on thetermination of service, a “specified employee” of the Company or any successorentity thereto, as such term is defined in Section 409A(a)(2)(B)(i) of theCode, then, solely to the extent necessary to avoid the incurrence of theadverse personal tax consequences under Section 409A, the timing of theSeverance Benefit payments shall be delayed until the earlier to occur of: (i)the date that is six months and one day after the Eligible Employee’sSeparation From Service, or (ii) the date of the Eligible Employee’s death(such applicable date, the “***Specified Employee InitialPayment Date***”), the Company (or the successor entity thereto, asapplicable) shall (A) pay to the Eligible Employee a lump sum amount equal tothe sum of the Severance Benefit payments that the Eligible Employee wouldotherwise have received through the Specified Employee Initial Payment Date ifthe commencement of the payment of the Severance Benefits had not been sodelayed pursuant to this Section and (B) commence paying the balance of theSeverance Benefits in accordance with the applicable payment schedules setforth in this Plan.

 

**(c)****          **Notwithstandinganything to the contrary set forth herein, the Eligible Employee shall receivethe Severance Benefits described above, if and only if the Eligible Employeeduly executes and returns to the Company within the applicable time period setforth therein, but in no event more

 

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thanforty-five days following Separation From Service, a separation agreementcontaining the Company’s standard form of release of claims in favor of theCompany (attached to this Agreement as Exhibits A, B and C) and otherstandard provisions, including without limitation, those relating tonon-disparagement and confidentiality (the “***SeparationAgreement***”), and permits the release of claims contained thereinto become effective in accordance with its terms.  Notwithstanding any other payment scheduleset forth in this Plan, none of the Severance Benefits will be paid orotherwise delivered prior to the effective date of the Separation Agreement.  Except to the extent that payments may bedelayed until the Specified Employee Initial Payment Date pursuant to thepreceding paragraph, on the first regular payroll pay day following theeffective date of the Separation Agreement, the Company will pay the EligibleEmployee the Severance Benefits the Eligible Employee would otherwise havereceived under the Plan on or prior to such date but for the delay in paymentrelated to the effectiveness of the Separation Agreement, with the balance ofthe Severance Benefits being paid as originally scheduled.

 

**Section 5.****             ****PARACHUTEPAYMENTS**

 

**(a)****          **In the eventthat the payments provided herein and benefits otherwise payable to an EligibleEmployee (i) constitute “parachute payments” within the meaning of Section 280Gof the Code, or any comparable successor provisions, and (ii) but for thisSection 5 would be subject to the excise tax imposed by Section 4999 of theCode, or any comparable successor provisions (the “***ExciseTax***”), then such Eligible Employee’s benefits hereunder shall beeither:

 

(i)            provided to such EligibleEmployee in full, or

 

(ii)           provided to such EligibleEmployee as to such lesser extent which would result in no portion of suchbenefits being subject to the Excise Tax,

 

whicheverof the foregoing amounts, when taking into account applicable federal, state,local and foreign income and employment taxes, the Excise Tax, and any otherapplicable taxes, results in the receipt by such Eligible Employee, on anafter-tax basis, of the greatest amount of benefits, notwithstanding that allor some portion of such benefits may be taxable under the Excise Tax (the “***Reduced Amount***”).  If a reduction in payments or benefitsconstituting “parachute payments” is necessary so that the Payment equals theReduced Amount, reduction shall occur in the following order:  reduction of cash payments; cancellation ofaccelerated vesting of stock awards; reduction of employee benefits.  If acceleration of vesting of stock awardcompensation is to be reduced, such acceleration of vesting shall be cancelledin the reverse order of the date of grant of the Eligible Employee’s stockawards.

 

**(b)****          **Unless theCompany and such Eligible Employee otherwise agree in writing, anydetermination required under this Section 5 shall be made in writing in goodfaith by the Company’s independent certified public accountants (the “***Accountants***”).  For purposes of making the calculationsrequired by this Section 5, the Accountants may make reasonable assumptions andapproximations concerning applicable taxes and may rely on reasonable, goodfaith interpretations concerning the application of the Code, and otherapplicable legal authority.  The Companyand such Eligible Employee

 

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shallfurnish to the Accountants such information and documents as the Accountantsmay reasonably request in order to make a determination under this Section5.  The Company shall bear all costs theAccountants may reasonably incur in connection with any calculations contemplatedby this Section 5.

 

**(c)****          **If, notwithstandingany reduction described in this Section 5, the IRS determines that suchEligible Employee is liable for the Excise Tax as a result of the receipt ofthe payment of benefits as described above, then such Eligible Employee shallbe obligated to pay back to the Company, within thirty (30) days after a finalIRS determination or in the event that such Eligible Employee challenges thefinal IRS determination, a final judicial determination, a portion of thepayment equal to the “Repayment Amount.” The Repayment Amount with respect to the payment of benefits shall bethe smallest such amount, if any, as shall be required to be paid to theCompany so that such Eligible Employee’s net after-tax proceeds with respect toany payment of benefits (after taking into account the payment of the ExciseTax and all other applicable taxes imposed on such payment) shall bemaximized.  The Repayment Amount withrespect to the payment of benefits shall be zero if a Repayment Amount of morethan zero would not result in such Eligible Employee’s net after-tax proceedswith respect to the payment of such benefits being maximized.  If the Excise Tax is not eliminated pursuantto this paragraph, such Eligible Employee shall pay the Excise Tax.

 

**(d)****          **                Notwithstanding any other provisionof this Section 5, if (i) there is a reduction in the payment of benefits asdescribed in this Section 5, (ii) the IRS later determines that such EligibleEmployee is liable for the Excise Tax, the payment of which would result in themaximization of such Eligible Employee’s net after-tax proceeds (calculated asif such Eligible Employee’s benefits had not previously been reduced), and(iii) such Eligible Employee pays the Excise Tax, then the Company shall pay tosuch Eligible Employee those benefits which were reduced pursuant to thisSection 5 contemporaneously or as soon as administratively possible after suchEligible Employee pays the Excise Tax so that such Eligible Employee’s netafter-tax proceeds with respect to the payment of benefits is maximized.

 

**(e)****          **If an EligibleEmployee either (i) brings any action to enforce such Eligible Employee’srights pursuant to this Section 5, or (ii) defends any legal challenge to suchEligible Employee’s rights hereunder, such Eligible Employee shall be entitledto recover attorneys’ fees and costs incurred in connection with such action,regardless of the outcome of such action; provided, however, that in the eventsuch action is commenced by such Eligible Employee, the court finds the claimwas brought in good faith.

 

**Section 6.****             ****IMPACTON OTHER EMPLOYEE BENEFITS**

 

**(a)****          ****Continued Group Health Plan Benefits. **If the Eligible Employee was enrolled in agroup health plan (*e.g*., medical,dental, or vision plan) sponsored by the Company or an affiliate immediately priorto termination, the Eligible Employee may be eligible to continue coverageunder such group health plan (or to convert to an individual policy), at thetime of the Eligible Employee’s termination of employment, under theConsolidated Omnibus Budget Reconciliation Act of 1985

 

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(“***COBRA***”).  The Company will notify the Eligible Employeeof any such right to continue such coverage at the time of termination pursuantto COBRA.  No provision of this Plan willaffect the continuation coverage rules under COBRA.

 

**(b)****          ****OtherEmployee Benefits.** All otherbenefits (such as life insurance, disability coverage, and 401(k) plancoverage) terminate as of the Eligible Employee’s termination date (except tothe extent that a conversion privilege may be available thereunder).

 

**Section 7.****             ****COMPANYPROPERTY.**

 

**(a)****          ****Returnof Company Property.**  Except asprovided in Section 7(b) below, an Eligible Employee will not be entitled toany severance benefit under the Plan unless and until the Eligible Employeereturns all Company Property.  For thispurpose, “***Company Property***” means allCompany documents (and all copies thereof) and other Company property which theEligible Employee had in his or her possession at any time, including, but notlimited to, Company files, notes, drawings records, plans, forecasts, reports,studies, analyses, proposals, agreements, financial information, research anddevelopment information, sales and marketing information, operational andpersonnel information, specifications, code, software, databases,computer-recorded information, tangible property and equipment (including, butnot limited to, leased vehicles, computers, facsimile machines, mobiletelephones, servers), credit cards, entry cards, identification badges andkeys; and any materials of any kind which contain or embody any proprietary orconfidential information of the Company (and all reproductions thereof in wholeor in part).  As a condition to receivingbenefits under the Plan, Eligible Employees must not make or retain copies,reproductions or summaries of any such Company property.

 

**(b)****          ****Retentionof Certain Company Equipment.**  Notwithstanding the provisions of Section7(a), the Company and an Eligible Employee may agree to allow the EligibleEmployee to retain certain Company equipment (*e.g*.,laptops, printers, facsimile machines, copiers, *etc.*)(“***Company Equipment***”) for his or herpersonal use following the Eligible Employee’s termination of employment.  As a condition to retaining any CompanyEquipment, the Eligible Employee must execute a general waiver and release insubstantially the form attached hereto as Exhibit A, Exhibit B or Exhibit C, asappropriate, and such release must become effective in accordance with itsterms. The Eligible Employee acknowledges that the Eligible Employee will haveimputed income related to the retention of any Company Equipment.  The Eligible Employee will follow all Companyinstructions as to the return and/or deletion of any Company informationcontained on the Company Equipment.

 

**Section 8.****             ****WITHHOLDINGTAXES AND OFFSETS FOR INDEBTEDNESS.**

 

Allpayments under the Plan will be subject to applicable withholding for federal,state and local taxes.  If an EligibleEmployee is indebted to the Company at his or her termination date, the Companyreserves the right to offset any severance payments under the Plan by theamount of such indebtedness to the extent permitted by applicable laws.  Additionally, if an Eligible Employee issubject

 

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towithholding for taxes related to any non-Plan benefits, the Company may offsetany severance payments under the Plan by the amount of such withholding taxes.

 

**Section 9.****             ****REEMPLOYMENT.**

 

In the event of an Eligible Employee’s reemploymentby the Company or an affiliate of the Company during the period of time inrespect of which severance benefits pursuant to Sections 3(a) and 3(b) havebeen paid, the Company, in its sole and absolute discretion, may require suchEligible Employee to repay to the Company all or a portion of such severancebenefits as a condition of reemployment.

 

**Section 10.****           ****RIGHTTO INTERPRET PLAN; AMENDMENT AND TERMINATION.**

 

**(a)****          ****ExclusiveDiscretion.**  The PlanAdministrator (as defined in Section 13(a) herein) shall have theexclusive discretion and authority to establish rules, forms, and proceduresfor the administration of the Plan and to construe and interpret the Plan andto decide any and all questions of fact, interpretation, definition,computation or administration arising in connection with the operation of thePlan, including, but not limited to, the eligibility to participate in the Planand amount of benefits paid under the Plan. The rules, interpretations, computations and other actions of the PlanAdministrator shall be binding and conclusive on all persons.

 

**(b)****          ****Amendmentor Termination.**  The Companyreserves the right to amend or terminate this Plan (including Appendix A andAppendix B) or the benefits provided hereunder at any time; *provided, however,*that no such amendment or terminationshall adversely affect the right to any unpaid benefit of any Eligible Employeewhose termination date has occurred prior to amendment or termination of thePlan.  In addition, following a Change ofControl, no such amendment or termination may adversely affect the benefits towhich an employee would become entitled under the Plan as an Eligible Employeeupon a Covered Termination if the Plan had not been so amended or terminated,without the consent of the affected employee. Furthermore, no such amendment or termination may adversely affect thebenefits to which a Company officer would become entitled under the Plan as anEligible Employee upon a Covered Termination if the Plan had not been soamended or terminated, without the consent of such affected officer.  Any action amending or terminating the Planshall be in writing and executed by the Chief Executive Officer or ChiefFinancial Officer of the Company.

 

**Section 11.****           ****NOIMPLIED EMPLOYMENT CONTRACT.**

 

ThePlan shall not be deemed (i) to give any employee or other person anyright to be retained in the employ of the Company or (ii) to interferewith the right of the Company to discharge any employee or other person at anytime, with or without cause, which right is hereby reserved.

 

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**Section 12.****           ****LEGALCONSTRUCTION.**

 

ThisPlan is intended to be governed by and shall be construed in accordance withthe Employee Retirement Income Security Act of 1974 (“***ERISA***”)and, to the extent not preempted by ERISA, the laws of the State of California(without regard to principles of conflict of laws).

 

**Section 13.****           ****CLAIMS, INQUIRIESAND APPEALS.**

 

**(a)****          ****Applicationsfor Benefits and Inquiries.**  Any application for benefits, inquiries aboutthe Plan or inquiries about present or future rights under the Plan must besubmitted to the Plan Administrator in writing by an applicant (or his or herauthorized representative).  The PlanAdministrator is:

 

Optimer Pharmaceuticals, Inc.

 

Attn:  Director of Human Resources

 

10110 Sorrento Valley Road, Suite C

 

San Diego, CA  92121

 

**(b)****          ****Denialof Claims.**  In the eventthat any application for benefits is denied in whole or in part, the PlanAdministrator must provide the applicant with written or electronic notice ofthe denial of the application, and of the applicant’s right to review thedenial.  Any electronic notice willcomply with the regulations of the U.S. Department of Labor.  The notice of denial will be set forth in a manner designed to be understood by theapplicant and will include the following:

 

**(1)****          **the specificreason or reasons for the denial;

 

**(2)****          **references tothe specific Plan provisions upon which the denial is based;

 

**(3)****          **a descriptionof any additional information or material that the Plan Administrator needs tocomplete the review and an explanation of why such information or material isnecessary; and

 

**(4)****          **an explanationof the Plan’s review procedures and the time limits applicable to suchprocedures, including a statement of the applicant’s right to bring a civilaction under Section 502(a) of ERISA following a denial on review ofthe claim, as described in Section 11(d) below.

 

Thisnotice of denial will be given to the applicant within ninety (90) days afterthe Plan Administrator receives the application, unless special circumstancesrequire an extension of time, in which case, the Plan Administrator has up toan additional ninety (90) days for processing the

 

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application.  If an extension of time for processing isrequired, written notice of the extension will be furnished to the applicantbefore the end of the initial ninety (90) day period.

 

Thisnotice of extension will describe the special circumstances necessitating theadditional time and the date by which the Plan Administrator is to render itsdecision on the application.

 

**(c)****          ****Requestfor a Review.**  Any person(or that person’s authorized representative) for whom an application forbenefits is denied, in whole or in part, may appeal the denial by submitting arequest for a review to the Plan Administrator within sixty (60) days after theapplication is denied.  A request for areview shall be in writing and shall be addressed to:

 

Optimer Pharmaceuticals, Inc.

 

Attn:  Director of Human Resources

 

10110 Sorrento Valley Road, Suite C

 

San Diego, CA  92121

 

Arequest for review must set forth all of the grounds on which it is based, allfacts in support of the request and any other matters that the applicant feelsare pertinent.  The applicant (or his orher representative) shall have the opportunity to submit (or the PlanAdministrator may require the applicant to submit) written comments, documents,records, and other information relating to his or her claim.  The applicant (or his or her representative)shall be provided, upon request and free of charge, reasonable access to, andcopies of, all documents, records and other information relevant to his or herclaim.  The review shall take intoaccount all comments, documents, records and other information submitted by theapplicant (or his or her representative) relating to the claim, without regardto whether such information was submitted or considered in the initial benefitdetermination.

 

**(d)****          ****Decisionon Review.**  The PlanAdministrator will act on each request for review within sixty (60) days afterreceipt of the request, unless special circumstances require an extension oftime (not to exceed an additional sixty (60) days), for processing the requestfor a review.  If an extension for reviewis required, written notice of the extension will be furnished to the applicantwithin the initial sixty (60) day period. This notice of extension will describe the special circumstancesnecessitating the additional time and the date by which the Plan Administratoris to render its decision on the review. The Plan Administrator will give prompt, written or electronic notice ofits decision to the applicant. Any electronic notice will comply with theregulations of the U.S. Department of Labor. In the event that the Plan Administrator confirms the denial of theapplication for benefits in whole or in part, the notice will set forth, in amanner calculated to be understood by the applicant, the following:

 

**(1)****          **the specificreason or reasons for the denial;

 

**(2)****          **references tothe specific Plan provisions upon which the denial is based;

 

13

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**(3)****          **a statementthat the applicant is entitled to receive, upon request and free of charge,reasonable access to, and copies of, all documents, records and otherinformation relevant to his or her claim; and

 

**(4)****          **a statement ofthe applicant’s right to bring a civil action under Section 502(a) ofERISA.

 

**(e)****          ****Rules andProcedures.**  The PlanAdministrator will establish rules and procedures, consistent with thePlan and with ERISA, as necessary and appropriate in carrying out itsresponsibilities in reviewing benefit claims. The Plan Administrator may require an applicant who wishes to submitadditional information in connection with an appeal from the denial of benefitsto do so at the applicant’s own expense.

 

**(f)****           ****Exhaustionof Remedies.**  No legalaction for benefits under the Plan may be brought until the applicant(i) has submitted a written application for benefits in accordance withthe procedures described by Section 13(a) above, (ii) has beennotified by the Plan Administrator that the application is denied,(iii) has filed a written request for a review of the application inaccordance with the appeal procedure described in Section 13(c) above,and (iv) has been notified that the Plan Administrator has denied theappeal.  Notwithstanding the foregoing,if the Plan Administrator does not respond to a applicant’s claim or appealwithin the relevant time limits specified in this Section 13, theapplicant may bring legal action for benefits under the Plan pursuant to Section 502(a) ofERISA.

 

**Section 14.****           ****BASISOF PAYMENTS TO AND FROM PLAN.**

 

ThePlan shall be unfunded, and all cash payments under the Plan shall be paid onlyfrom the general assets of the Company. An Eligible Employee’s right to receive payments under the Plan is nogreater than that of the Company’s unsecured general creditors.  Therefore, if the Company were to becomeinsolvent, the Eligible Employee might not receive benefits under the Plan.

 

**Section 15.****           ****OTHERPLAN INFORMATION.**

 

**(a)****          ****Employerand Plan Identification Numbers.** The Employer IdentificationNumber assigned to the Company (which is the “***PlanSponsor***” as that term is used in ERISA) by the Internal RevenueService is 33-0830300.  The Plan Numberassigned to the Plan by the Plan Sponsor pursuant to the instructions of theInternal Revenue Service is****511.

 

**(b)****          ****EndingDate for Plan’s Fiscal Year and Type of Plan.**  The date of the end of the fiscal year forthe purpose of maintaining the Plan’s records is December 31.  The Plan is a welfare benefit plan.

 

**(c)****          ****Agentfor the Service of Legal Process.**  The agent for the service of legal processwith respect to the Plan is:

 

14

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Optimer Pharmaceuticals, Inc.

 

Attn:  Director of HumanResources

 

10110 Sorrento Valley Road, Suite C

 

San Diego, CA  92121

 

**(d)****          ****PlanSponsor and Administrator.**  The Plan Sponsor and the “***Plan Administrator***” of the Plan is:

 

Optimer Pharmaceuticals, Inc.

 

Attn:  Director of HumanResources

 

10110 Sorrento Valley Road, Suite C

 

San Diego, CA  92121

 

The Plan Sponsor’s and Plan Administrator’stelephone number is (858) 909-0736.  ThePlan Administrator is the named fiduciary charged with the responsibility foradministering the Plan.

 

**Section 16.****           ****STATEMENTOF ERISA RIGHTS.**

 

Participantsin this Plan are entitled to certain rights and protections under ERISA.  If you are an Eligible Employee, you areconsidered a participant in the Plan and, under ERISA, you are entitled to:

 

**(a)****          ****ReceiveInformation About Your Plan and Benefits**

 

**(1)****          **Examine,without charge, at the Plan Administrator’s office and at other specifiedlocations, such as worksites, all documents governing the Plan and a copy ofthe latest annual report (Form 5500 Series), if applicable, filed by thePlan with the U.S. Department of Labor and available at the Public Disclosure Room ofthe Employee Benefits Security Administration;

 

**(2)****          **Obtain, uponwritten request to the Plan Administrator, copies of documents governing theoperation of the Plan and copies of the latest annual report (Form 5500Series), if applicable, and an updated (as necessary) Summary PlanDescription.  The Administrator may makea reasonable charge for the copies; and

 

**(3)****          **Receive asummary of the Plan’s annual financial report, if applicable.  The Plan Administrator is required by law tofurnish each participant with a copy of this summary annual report.

 

15

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**(b)****          ****Prudent Actions by Plan Fiduciaries.**  In addition to creating rights for Planparticipants, ERISA imposes duties upon the people who are responsible for theoperation of the employee benefit plan. The people who operate the Plan, called “fiduciaries” of the Plan, havea duty to do so prudently and in the interest of you and other Planparticipants and beneficiaries.  No one,including your employer, your union or any other person, may fire you orotherwise discriminate against you in any way to prevent you from obtaining aPlan benefit or exercising your rights under ERISA.

 

**(c)****          ****Enforce Your Rights. **If your claimfor a Plan benefit is denied or ignored, in whole or in part, you have a rightto know why this was done, to obtain copies of documents relating to thedecision without charge, and to appeal any denial, all within certain timeschedules as set forth in detail in Section 13 herein.

 

UnderERISA, there are steps you can take to enforce the above rights.  For instance, if you request a copy of Plandocuments or the latest annual report from the Plan, if applicable, and do notreceive them within 30 days, you may file suit in a Federal court and you arenot required to follow the claims procedure set forth in Section 13herein.  In such a case, the court mayrequire the Plan Administrator to provide the materials and pay you up to $110a day until you receive the materials, unless the materials were not sentbecause of reasons beyond the control of the Plan Administrator.

 

Ifyou have completed the claims and appeals procedure described in Section 11and have a claim for benefits which is denied or ignored, in whole or in part,you may file suit in a state or Federal court.

 

Ifyou are discriminated against for asserting your rights, you may seekassistance from the U.S. Department of Labor, or you may file suit in a Federalcourt.  The court will decide who shouldpay court costs and legal fees.  If youare successful, the court may order the person you have sued to pay these costsand fees.  If you lose, the court mayorder you to pay these costs and fees, for example, if it finds your claim isfrivolous.

 

**(d)****          ****Assistance with Your Questions. **If you have anyquestions about the Plan, you should contact the Plan Administrator.  If you have any questions about thisstatement or about your rights under ERISA, or if you need assistance inobtaining documents from the Plan Administrator, you should contact the nearestoffice of the Employee Benefits Security Administration, U.S. Department ofLabor, listed in your telephone directory or the Division of TechnicalAssistance and Inquiries, Employee Benefits Security Administration, U.S.Department of Labor, 200 Constitution Avenue N.W., Washington, D.C. 20210.  You may also obtain certain publicationsabout your rights and responsibilities under ERISA by calling the publicationshotline of the Employee Benefits Security Administration or accessing itswebsite at http://www.dol.gov/ebsa/.

 

16

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**Section 17.****           ****GENERALPROVISIONS.**

 

**(a)****          ****Notices. **Any notice, demand orrequest required or permitted to be given by either the Company or an EligibleEmployee pursuant to the terms of this Plan shall be in writing and shall bedeemed given when delivered personally or deposited in the U.S. mail, First Class withpostage prepaid, and addressed to the parties, in the case of the Company, atthe address set forth in Section 15(d) and, in the case of anEligible Employee, at the address as set forth in the Company’s employment filemaintained for the Eligible Employee as previously furnished by the EligibleEmployee or such other address as a party may request by notifying the other inwriting.

 

**(b)****          ****Transferand Assignment. **The rights andobligations of an Eligible Employee under this Plan may not be transferred,assigned or alienated.  This Plan shallbe binding upon any surviving entity resulting from a Change of Control andupon any other person who is a successor by merger, acquisition, consolidationor otherwise to the business formerly carried on by the Company without regardto whether or not such person or entity actively assumes the obligationshereunder.

 

**(c)****          ****Waiver.** Any party’s failure to enforceany provision or provisions of this Plan shall not in any way be construed as awaiver of any such provision or provisions, nor prevent any party fromthereafter enforcing each and every other provision of this Plan.  The rights granted the parties herein arecumulative and shall not constitute a waiver of any party’s right to assert allother legal remedies available to it under the circumstances.

 

**(d)****          ****Severability.** Should any provision of thisPlan be declared or determined to be invalid, illegal or unenforceable, thevalidity, legality and enforceability of the remaining provisions shall not inany way be affected or impaired.

 

**(e)****          ****Section Headings.**  Section headings in this Plan areincluded for convenience of reference only and shall not be considered part ofthis Plan for any other purpose.

 

**Section 18.****           ****EXECUTION.**

 

Torecord the adoption of the Plan as set forth herein, effective as of May 5, 2010, OptimerPharmaceuticals, Inc.****hascaused its duly authorized officer to execute the same this 5th day of May, 2010.

 

 
|   | **OPTIMER  PHARMACEUTICALS, INC.** |
|--------|-----------------------------------------|
|   |                                    |
|   |                                    |
|   | By:                                     | /s/  John D. Prunty |
|   |                                    |   |
|   | Title:                                  | Chief  Financial Officer and Vice President |

 

17

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**APPENDIX A**

 

**OPTIMER PHARMACEUTICALS, INC.SEVERANCE BENEFIT PLAN**

 

**BENEFITS FOR ELIGIBLE EMPLOYEESWITH LESS THAN ONE YEAR OF SERVICE**

 

Certaincapitalized terms not specifically defined in this Appendix A are defined inthe Plan.

 

Severancebenefits to be provided to Eligible Employees under the Optimer Pharmaceuticals, Inc.****Amended and Restated Severance Benefit Plan (the “***Plan***”) who are terminated pursuantto a Covered Termination and who have less than one Year of Service on the dateof such termination are as provided on this Appendix A.

 

**1.****            ****Conditionsto Receipt of Benefits:** Subject to the exceptions set forth in Section 2(b) ofthe Plan, the Eligible Employee must meet all the requirements set forth inSections 2(a) and 7(a) of the Plan, including, without limitation,executing a general waiver and release in substantially the form attached tothe Plan as **Exhibit A**, **Exhibit B** or **Exhibit C**,as appropriate (the “***Release***”),within the applicable time period set forth therein and permit such release tobecome effective in accordance with its terms. The Company, in its sole discretion, may modify the form of the requiredgeneral waiver and release to comply with applicable law, and may incorporatesuch waiver and release into a termination agreement or other agreement withthe Eligible Employee.

 

**2.****            ****RegularCovered Termination Severance Benefits. **Eligible Employees that are terminated in a Covered Termination thatoccurs either prior to, or more than 12 months following, a Change of Control,and who have less than one Year of Service on the date of such termination,shall receive the benefits set forth in this Section 2.

 

**(a)****          ****BaseSalary Continuation Benefit.** Eligible Employees shall be entitled toreceive continued Base Salarypayments for the time period following a Covered Termination as set forth belownext to the respective Eligible Employees’ position in effect at the time ofthe Covered Termination.

 
| **Position**                                                                                            | ** ** | **Base Salary Continuation Period**             |
|---------------------------------------------------------------------------------------------------------|------------|-------------------------------------------------|
| ** **                                                                                              | ** ** | ** **                                      |
| Chief  Executive Officer                                                                                |       | 6 months                                        |
|                                                                                                    |       |                                            |
| Company  Officers and Vice Presidents                                                                   |       | 3 months                                        |
|                                                                                                    |       |                                            |
| All  Director levels, Managers, and Non-Managerial Staff with annual Base Salary  in excess of $100,000 |       | 2 weeks, plus  2 weeks for each Year of Service |
|                                                                                                    |       |                                            |
| Non-Managerial  Staff with annual Base                                                                  |       | 2 weeks, plus                                   |

 

1

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| Salary  of $100,000 or less |   | 1 week for each Year of Service |
|-----------------------------|--------|---------------------------------|

 

**(b)****          ****VestingAcceleration for Non-Performance Vesting Equity Awards. **All Non-Performance VestingEquity Awards granted by the Company to the Eligible Employee (determined as ofthe date of the Eligible Employee’s Covered Termination) shall be subject toaccelerated vesting, if any, for the time period or to the extent set forthbelow next to the Eligible Employee’s respective position.  If such accelerated vesting is with respectto less than 100% of the Non-Performance Vesting Equity Award, if applicable,such acceleration shall be determined in accordance with the vesting scheduleapplicable to such Equity Award as if the Eligible Employee had been employedfor the additional period of time indicated next to the Eligible Employee’sposition as of the date of his or her Covered Termination.

 
| **Position**                                                                                              | ** ** | **Time Period or Extent of Vesting**

**Acceleration for  Non-Performance Vesting Equity  Awards** |
|-----------------------------------------------------------------------------------------------------------|------------|----------------------------------------------------------------------------------------------------|
| ** **                                                                                                | ** ** | ** **                                                                                         |
| Chief  Executive Officer                                                                                  |       | 6 months                                                                                           |
|                                                                                                      |       |                                                                                               |
| Company  Officers and Vice Presidents                                                                     |       | 6 months                                                                                           |
|                                                                                                      |       |                                                                                               |
| All  Director levels, Managers, , and Non-Managerial Staff with annual Base Salary  in excess of $100,000 |       | None                                                                                               |
|                                                                                                      |       |                                                                                               |
| Non-Managerial  Staff with annual Base Salary of $100,000 or less                                         |       | None                                                                                               |

 

**3.****            ****Changeof Control Covered Termination Severance Benefits. **Eligible Employees that areterminated in a Covered Termination that occurs upon or within twelve (12)months following a Change of Control, and who have less than one Year ofService on the date of such termination shall receive the benefits set forth inthis Section 3.

 

**(a)****          ****BaseSalary Continuation Benefit.** Eligible Employees shall be entitled toreceive continued Base Salarypayments for the time period following a Covered Termination as set forth belownext to the respective Eligible Employees’ position in effect at the time ofthe Covered Termination.

 

2

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| **Position**                                                                                            | ** ** | **Base Salary Continuation Period**             |
|---------------------------------------------------------------------------------------------------------|------------|-------------------------------------------------|
|                                                                                                    |       |                                            |
| Chief  Executive Officer                                                                                |       | 12 months                                       |
|                                                                                                    |       |                                            |
| Company  Officers and Vice Presidents                                                                   |       | 6 months                                        |
|                                                                                                    |       |                                            |
| All  Director levels, Managers, and Non-Managerial Staff with annual Base Salary  in excess of $100,000 |       | 2 weeks, plus  2 weeks for each Year of Service |

 

3

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| Non-Managerial  Staff with annual Base Salary of $100,000 or less |   | 2 weeks, plus  1 week for each Year of Service |
|-------------------------------------------------------------------|--------|------------------------------------------------|

 

**(b)****          ****VestingAcceleration of Equity Awards.**

 

**(1)****          **All Non-Performance VestingEquity Awards granted by the Company to the Eligible Employee (determined as ofthe date of the Eligible Employee’s Covered Termination) shall be subject toaccelerated vesting for the time period or to the extent set forth below nextto the Eligible Employee’s respective position. If such accelerated vesting is with respect to less than 100% of theEquity Award such acceleration shall be determined in accordance with thevesting schedule applicable to such Equity Award as if the Eligible Employeehad been employed for the additional period of time indicated next to theEligible Employee’s position as of the date of his or her Covered Termination.

 
| **Position**                                                                                            | ** ** | **Time Period or Extent of Vesting  Acceleration for  Non-Performance Vesting Equity Awards** |
|---------------------------------------------------------------------------------------------------------|------------|-----------------------------------------------------------------------------------------------|
|                                                                                                    |       |                                                                                          |
| Chief  Executive Officer                                                                                |       | All unvested Equity Awards immediately vest 100%                                              |
|                                                                                                    |       |                                                                                          |
| Company  Officers and Vice Presidents                                                                   |       | All unvested Equity Awards immediately vest 100%                                              |
|                                                                                                    |       |                                                                                          |
| All  Director levels, Managers, and Non-Managerial Staff with annual Base Salary  in excess of $100,000 |       | 12 months                                                                                     |
|                                                                                                    |       |                                                                                          |
| Non-Managerial  Staff with annual Base Salary of $100,000 or less                                       |       | 12 months                                                                                     |

 

**(2)****          **Any Performance VestingEquity Awards (determined as of the date of the Eligible Employee’s CoveredTermination) shall be subject to accelerated vesting with respect to 50% of thethen unvested shares.

 

**4.****            ****Timeand Form of Base Salary Continuation Payments. **Subject to the provisions ofSection 4 of the Plan, all Base Salary continuation payments shall be paidin accordance with the Company’s standard payroll practices, and shall commencewith the first payroll period following the effective date of the Release.  The Company will pay the Eligible Employeethe Base Salary continuation severance benefits the Eligible Employee wouldotherwise have received under the

 

4

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Plan on or prior to such date but for the delay in payment related tothe effectiveness of the Release, with the balance of the Base Salarycontinuation severance benefits being paid as originally scheduled.

 

**5.****            ****ReductionsPursuant to Section 3(c) of the Plan. **The severance benefits set forthin this Appendix A are subject to certain reductions under Section 3(c) ofthe Plan.

 

**6.****            ****Amendmentof Appendix A.** The foregoingseverance benefits are subject to such change as the Company, pursuant to Section 10(b) ofthe Plan, may determine in its sole and absolute discretion.  Any such change in severance benefits shallbe set forth in a revised version of this Appendix A.

 

5

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**APPENDIX B**

 

**OPTIMER PHARMACEUTICALS, INC.SEVERANCE BENEFIT PLAN**

 

**BENEFITS FOR ELIGIBLE EMPLOYEESWITH ONE OR MORE YEARS OF SERVICE**

 

Certaincapitalized terms not specifically defined in this Appendix B are defined inthe Plan.

 

Severancebenefits to be provided to Eligible Employees under the Optimer Pharmaceuticals, Inc.****Amended and Restated****SeveranceBenefit Plan (the “***Plan***”) who are terminatedpursuant to a Covered Termination and who have one or more Years of Service onthe date of such termination are as provided on this Appendix B.

 

**1.****            ****Conditionsto Receipt of Benefits:** Subject to the exceptions set forth in Section 2(b) ofthe Plan, the Eligible Employee must meet all the requirements set forth inSections 2(a) and 7(a) of the Plan, including, without limitation,executing a general waiver and release in substantially the form attached tothe Plan as **Exhibit A**, **Exhibit B** or **Exhibit C**,as appropriate (the “***Release***”),within the applicable time period set forth therein and permit such release tobecome effective in accordance with its terms. The Company, in its sole discretion, may modify the form of the requiredgeneral waiver and release to comply with applicable law, and may incorporatesuch waiver and release into a termination agreement or other agreement withthe Eligible Employee.

 

**2.****            ****RegularCovered Termination Severance Benefits. **Eligible Employees that are terminated in a Covered Termination thatoccurs either prior to, or more than 12 months following, a Change of Control,and who have one or more Years of Service on the date of such termination,shall receive the benefits set forth in this Section 2.

 

**(a)****          ****BaseSalary Continuation Benefit.** Eligible Employees shall be entitled toreceive continued Base Salarypayments for the time period following a Covered Termination as set forth belownext to the respective Eligible Employees’ position in effect at the time ofthe Covered Termination.

 

1

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| **Position**                                                                                            | ** ** | **Base Salary Continuation Period**                                                          |
|---------------------------------------------------------------------------------------------------------|------------|----------------------------------------------------------------------------------------------|
|                                                                                                    |       |                                                                                         |
| Chief  Executive Officer                                                                                |       | 12  months                                                                                   |
|                                                                                                    |       |                                                                                         |
| Company  Officers                                                                                       |       | 6  months, plus  1 month for each Year of Service above 1 year, up to a maximum of 12 months |
|                                                                                                    |       |                                                                                         |
| Vice  Presidents                                                                                        |       | 3  months, plus  1 month for each Year of Service above 3 years, up to a maximum of 9 months |
|                                                                                                    |       |                                                                                         |
| All  Director levels, Managers, and Non-Managerial Staff with annual Base Salary  in excess of $100,000 |       | 2  weeks, plus  2 weeks for each Year of Service, up to a maximum of 36 weeks                |
|                                                                                                    |       |                                                                                         |
| Non-Managerial  Staff with annual Base Salary of $100,000 or less                                       |       | 2  weeks, plus  1 week for each Year of Service, up to a maximum of 26 weeks                 |

 

2

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**(b)****          ****VestingAcceleration for Non-Performance Vesting Equity Awards. **All Non-Performance VestingEquity Awards granted by the Company to the Eligible Employee (determined as ofthe date of the Eligible Employee’s Covered Termination) shall be subject toaccelerated vesting, if any, for the time period or to the extent set forthbelow next to the Eligible Employee’s respective position.  If such accelerated vesting is with respectto less than 100% of the Equity Award such acceleration shall be determined inaccordance with the vesting schedule applicable to such Equity Award as if theEligible Employee had been employed for the additional period of time indicatednext to the Eligible Employee’s position as of the date of his or her CoveredTermination.

 
| **Position**                                                                                            | ** ** | **Time Period or Extent of Vesting  Acceleration for  Non-Performance Vesting Equity  Awards** |
|---------------------------------------------------------------------------------------------------------|------------|------------------------------------------------------------------------------------------------|
|                                                                                                    |       |                                                                                           |
| Chief  Executive Officer                                                                                |       | 24  months                                                                                     |
|                                                                                                    |       |                                                                                           |
| Company  Officers and Vice Presidents                                                                   |       | 12  months                                                                                     |
|                                                                                                    |       |                                                                                           |
| Managers,  Executive Directors, and Non-Managerial Staff with annual Base Salary in  excess of $100,000 |       | None                                                                                           |
|                                                                                                    |       |                                                                                           |
| Non-Managerial  Staff with annual Base Salary of $100,000 or less                                       |       | None                                                                                           |

 

**3.****            ****Change ofControl Covered Termination Severance Benefits. **Eligible Employees that are terminated in aCovered Termination that occurs upon or within twelve (12) months following aChange of Control, and who have one or more Years of Service on the dateof such termination shall receive the benefits set forth in this Section 3.

 

**(a)****          ****BaseSalary Continuation Benefit.** Eligible Employees shall be entitled toreceive continued Base Salarypayments for the time period following a Covered Termination as set forth belownext to the respective Eligible Employees’ position in effect at the time ofthe Covered Termination.

 

3

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| **Position**                                                                                            | ** ** | **Base Salary Continuation Period**                                          |
|---------------------------------------------------------------------------------------------------------|------------|------------------------------------------------------------------------------|
| ** **                                                                                              | ** ** | ** **                                                                   |
| Chief  Executive Officer                                                                                |       | 12 months                                                                    |
|                                                                                                    |       |                                                                         |
| Company  Officers                                                                                       |       | 12 months                                                                    |
|                                                                                                    |       |                                                                         |
| Vice  Presidents                                                                                        |       | 9 months                                                                     |
|                                                                                                    |       |                                                                         |
| Managers,  Executive Directors, and Non-Managerial Staff with annual Base Salary in  excess of $100,000 |       | 2 weeks, plus  2 weeks for each Year of Service, up to a maximum of 36 weeks |
|                                                                                                    |       |                                                                         |
| Non-Managerial  Staff with annual Base Salary of $100,000 or less                                       |       | 2 weeks, plus  1 week for each Year of Service, up to a maximum of 26 weeks  |

 

**(b)****          ****EquityVesting Acceleration.**

 

**(1)****          ****VestingAcceleration for Non-Performance Vesting Equity Awards. **All Non-Performance VestingEquity Awards granted by the Company to the Eligible Employee (determined as ofthe date of the Eligible Employee’s Covered Termination) shall be subject toaccelerated vesting for the time period or to the extent set forth below nextto the Eligible Employee’s respective position.

 
| **Position**                                                                                            | ** ** | **Time Period or Extent of Vesting  Acceleration for  Non-Performance Vesting Equity Awards** |
|---------------------------------------------------------------------------------------------------------|------------|-----------------------------------------------------------------------------------------------|
|                                                                                                    |       |                                                                                          |
| Chief  Executive Officer                                                                                |       | immediately vest 100%                                                                         |
|                                                                                                    |       |                                                                                          |
| Company  Officers and Vice Presidents                                                                   |       | immediately vest 100%                                                                         |
|                                                                                                    |       |                                                                                          |
| Managers,  Executive Directors, and Non-Managerial Staff with annual Base Salary in  excess of $100,000 |       | immediately vest 100%                                                                         |
|                                                                                                    |       |                                                                                          |
| Non-Managerial  Staff with annual Base Salary of $100,000 or less                                       |       | immediately vest 100%                                                                         |

 

4

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**(2)****          **Any Performance Vesting EquityAwards (determined as of the date of the Eligible Employee’s CoveredTermination) shall be subject to accelerated vesting, if any, to the extent setforth below.

 
| **Years  of Service at time of Covered  Termination** | ** ** | **Extent of Vesting Acceleration for  Performance Vesting Equity Award** |
|-------------------------------------------------------|------------|--------------------------------------------------------------------------|
|                                                  |       |                                                                     |
| At  least one, but less than 2                        |       | 60% of unvested shares at time of Covered Termination                    |
|                                                  |       |                                                                     |
| At  least 2, but less than 3                          |       | 75% of unvested shares at time of Covered Termination                    |
|                                                  |       |                                                                     |
| At  least 3, but less than 4                          |       | 85% of unvested shares at time of Covered Termination                    |
|                                                  |       |                                                                     |
| At  least 4                                           |       | 100% of unvested shares at time of Covered Termination                   |

 

**4.****            ****Timeand Form of Base Salary Continuation Payments. **Subject to the provisions ofSection 4 of the Plan, all Base Salary continuation payments shall be paidin accordance with the Company’s standard payroll practices, and shall commencewith the first payroll period following the effective date of the Release.  The Company will pay the Eligible Employeethe Base Salary continuation severance benefits the Eligible Employee wouldotherwise have received under the Plan on or prior to such date but for thedelay in payment related to the effectiveness of the Release, with the balanceof the Base Salary continuation severance benefits being paid as originallyscheduled.

 

**5.****            ****ReductionsPursuant to Section 3(c) of the Plan. **The severance benefits set forthin this Appendix B are subject to certain reductions under Section 3(c) ofthe Plan.

 

**6.****            ****Amendmentof Appendix B.** The foregoingseverance benefits are subject to such change as the Company, pursuant to Section 10(b) ofthe Plan, may determine in its sole and absolute discretion.  Any such change in severance benefits shallbe set forth in a revised version of this Appendix B.

 

5

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**APPENDIX C**

 

**CERTAIN EQUITY AWARDS**

** **

 
| **Award  Type**        | ** ** | **Grantee**       | ** ** | **Shares Covered by  Award** | ** ** | **Grant Date**   |
|------------------------|------------|-------------------|------------|------------------------------|------------|------------------|
| ** **             | ** ** | ** **        | ** ** | ** **                   | ** ** | ** **       |
| Restricted  Stock Unit |       | Pedro  Lichtinger |       | 20,000                       |       | May 5, 2010 |
|                   |       |              |       |                         |       |             |
| Restricted  Stock Unit |       | Pedro  Lichtinger |       | 20,000                       |       | May 5, 2010 |
|                   |       |              |       |                         |       |             |
| Restricted  Stock Unit |       | Pedro  Lichtinger |       | 20,000                       |       | May 5, 2010 |
|                   |       |              |       |                         |       |             |
| Restricted  Stock Unit |       | Pedro  Lichtinger |       | 60,000                       |       | May 5, 2010 |
|                   |       |              |       |                         |       |             |
| Stock  Option          |       | Pedro  Lichtinger |       | 80,000                       |       | May 5, 2010 |
|                   |       |              |       |                         |       |             |
| Stock  Option          |       | Pedro  Lichtinger |       | 80,000                       |       | May 5, 2010 |
|                   |       |              |       |                         |       |             |
| Stock  Option          |       | Pedro  Lichtinger |       | 80,000                       |       | May 5, 2010 |
|                   |       |              |       |                         |       |             |
| Stock  Option          |       | Pedro  Lichtinger |       | 240,000                      |       | May 5, 2010 |

 

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For Employees Age 40 orOlder

 

Individual Termination

 

**EXHIBIT A**

 

**RELEASE AGREEMENT**

 

**I understand and agree completely to the terms set forth in the OptimerPharmaceuticals, Inc. Severance Benefit Plan (the “Plan”).**

 

I understand that this Release, together with the Plan, constitutes thecomplete, final and exclusive embodiment of the entire agreement between theCompany, affiliates of the Company and me with regard to the subject matterhereof.  I am not relying on any promiseor representation by the Company that is not expressly stated therein.  Certain capitalized terms used in thisRelease are defined in the Plan.

 

I hereby confirm my obligations under my proprietary information andinventions agreement with the Company.

 

Except as otherwise set forth in this Release, I hereby generallyand completely release the Company and its parents, subsidiaries, successors,predecessors and affiliates, and their partners, members, directors, officers,employees, stockholders, shareholders, agents, attorneys, predecessors,insurers, affiliates and assigns, from any and all claims, liabilities andobligations, both known and unknown, that arise out of or are in any wayrelated to events, acts, conduct, or omissions occurring at any time prior toand including the date I sign this Release. This general release includes, but is not limited to: (a) allclaims arising out of or in any way related to my employment with the Company,or its affiliates, or the termination of that employment; (b) all claimsrelated to my compensation or benefits, including salary, bonuses, commissions,vacation pay, expense reimbursements, severance pay, fringe benefits, stock,stock options, or any other ownership interests in the Company, or itsaffiliates; (c) all claims for breach of contract, wrongful termination,and breach of the implied covenant of good faith and fair dealing; (d) alltort claims, including claims for fraud, defamation, emotional distress, anddischarge in violation of public policy; and (e) all federal, state, andlocal statutory claims, including claims for discrimination, harassment,retaliation, attorneys’ fees, or other claims arising under the federal CivilRights Act of 1964 (as amended), the federal Americans with Disabilities Act of1990 (as amended), the federal Age Discrimination in Employment Act (asamended) (“***ADEA***”), the federal EmployeeRetirement Income Security Act of 1974 (as amended), and the California FairEmployment and Housing Act (as amended); *p**rovided, however,* that nothing in this paragraph shall beconstrued in any way to release the Company or its affiliates from itsobligation to indemnify me pursuant to agreement or applicable law.

 

I acknowledge that I am knowingly and voluntarily waiving and releasingany rights I may have under the ADEA, and that the consideration given underthe Plan for the waiver and release in the preceding paragraph hereof is inaddition to anything of value to which I was already entitled.  I further acknowledge that I have been advisedby this writing, as required by the ADEA, that: (a) my waiver and

 

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releasedo not apply to any rights or claims that may arise after the date I sign thisRelease; (b) I should consult with an attorney prior to signing thisRelease (although I may choose voluntarily not do so); (c) I havetwenty-one (21) days to consider this Release (although I may choosevoluntarily to sign this Release earlier); (d) I have seven (7) daysfollowing the date I sign this Release to revoke the Release by providingwritten notice to an officer of the Company; and (e) this Release shallnot be effective until the date upon which the revocation period has expired,which shall be the eighth day after I sign this Release.

 

I acknowledge that I have read and understand Section 1542 of theCalifornia Civil Code which reads as follows: **“A generalrelease does not extend to claims which the creditor does not know or suspectto exist in his favor at the time of executing the release, which if known byhim must have materially affected his settlement with the debtor.”**  I hereby expressly waive and relinquish allrights and benefits under that section and any law of any jurisdiction ofsimilar effect with respect to my release of any claims hereunder.

 

I acknowledge that to become effective, I must sign and return thisRelease to the Company so that it is received not later than twenty-one (21)days following the date it is provided to me.

 
|   | **EMPLOYEE** |
|--------|--------------|
|   |         |
|   |         |
|   | Name:        |   |
|   |         |   |
|   | Date:        |   |

 

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For Employees Age 40 orOlder

 

Group Termination

 

**EXHIBIT B**

 

**RELEASE AGREEMENT**

 

**I understand and agree completely to the terms set forth in the OptimerPharmaceuticals, Inc. Severance Benefit Plan (the “Plan”).**

 

I understand that this Release, together with the Plan, constitutes thecomplete, final and exclusive embodiment of the entire agreement between theCompany, affiliates of the Company and me with regard to the subject matterhereof.  I am not relying on any promiseor representation by the Company that is not expressly stated therein.  Certain capitalized terms used in thisRelease are defined in the Plan.

 

I hereby confirm my obligations under my proprietary information andinventions agreement with the Company.

 

Except as otherwise set forth in this Release, I hereby generallyand completely release the Company and its parents, subsidiaries, successors,predecessors and affiliates, and their partners, members, directors, officers,employees, stockholders, shareholders, agents, attorneys, predecessors,insurers, affiliates and assigns, from any and all claims, liabilities andobligations, both known and unknown, that arise out of or are in any wayrelated to events, acts, conduct, or omissions occurring at any time prior toand including the date I sign this Release. This general release includes, but is not limited to: (a) allclaims arising out of or in any way related to my employment with the Company,or its affiliates, or the termination of that employment; (b) all claimsrelated to my compensation or benefits, including salary, bonuses, commissions,vacation pay, expense reimbursements, severance pay, fringe benefits, stock,stock options, or any other ownership interests in the Company, or itsaffiliates; (c) all claims for breach of contract, wrongful termination,and breach of the implied covenant of good faith and fair dealing; (d) alltort claims, including claims for fraud, defamation, emotional distress, anddischarge in violation of public policy; and (e) all federal, state, andlocal statutory claims, including claims for discrimination, harassment,retaliation, attorneys’ fees, or other claims arising under the federal CivilRights Act of 1964 (as amended), the federal Americans with Disabilities Act of1990 (as amended), the federal Age Discrimination in Employment Act (asamended) (“***ADEA***”), the federal EmployeeRetirement Income Security Act of 1974 (as amended), and the California FairEmployment and Housing Act (as amended); *p**rovided, however,* that nothing in this paragraph shall beconstrued in any way to release the Company or its affiliates from itsobligation to indemnify me pursuant to agreement or applicable law.

 

I acknowledge that I am knowingly and voluntarily waiving and releasingany rights I may have under the ADEA, and that the consideration given underthe Plan for the waiver and release in the preceding paragraph hereof is inaddition to anything of value to which I was already entitled.  I further acknowledge that I have beenadvised by this writing, as required by the ADEA, that:  (a) my waiver and

 

1

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releasedo not apply to any rights or claims that may arise after the date I sign thisRelease; (b) I should consult with an attorney prior to signing thisRelease (although I may choose voluntarily not to do so); (c) I haveforty-five (45) days to consider this Release (although I may choosevoluntarily to sign this Release earlier); (d) I have seven (7) daysfollowing the date I sign this Release to revoke the Release by providingwritten notice to an office of the Company; (e) this Release shall not beeffective until the date upon which the revocation period has expired, whichshall be the eighth day after I sign this Release; and (f) I have receivedwith this Release a detailed list of the job titles and ages of all employeeswho were terminated in this group termination and the ages of all employees ofthe Company in the same job classification or organizational unit who were notterminated.

 

I acknowledge that I have read and understand Section 1542 of theCalifornia Civil Code which reads as follows: **“A generalrelease does not extend to claims which the creditor does not know or suspectto exist in his favor at the time of executing the release, which if known byhim must have materially affected his settlement with the debtor.”**  I hereby expressly waive and relinquish allrights and benefits under that section and any law of any jurisdiction ofsimilar effect with respect to my release of any claims hereunder.

 

I acknowledge that to become effective, I must sign and returnthis Release to the Company so that it is received not later than forty-five(45) days following the date it is provided to me.

 
|   | **EMPLOYEE** |
|--------|--------------|
|   |         |
|   |         |
|   | Name:        |   |
|   |         |   |
|   | Date:        |   |

 

2

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For Employees Under Age 40

 

Individual and Group Termination

 

**EXHIBIT C**

 

**RELEASE AGREEMENT**

 

**I understand and agree completely to the terms set forth in the OptimerPharmaceuticals, Inc. Severance Benefit Plan (the “Plan”).**

 

I understand that this Release, together with the Plan, constitutes thecomplete, final and exclusive embodiment of the entire agreement between theCompany, affiliates of the Company and me with regard to the subject matterhereof.  I am not relying on any promiseor representation by the Company that is not expressly stated therein.  Certain capitalized terms used in thisRelease are defined in the Plan.

 

I hereby confirm my obligations under my proprietary information andinventions agreement with the Company.

 

Except as otherwise set forth in this Release, I hereby generallyand completely release the Company and its parents, subsidiaries, successors,predecessors and affiliates, and their partners, members, directors, officers,employees, stockholders, shareholders, agents, attorneys, predecessors,insurers, affiliates and assigns, from any and all claims, liabilities andobligations, both known and unknown, that arise out of or are in any wayrelated to events, acts, conduct, or omissions occurring at any time prior toand including the date I sign this Release. This general release includes, but is not limited to: (a) allclaims arising out of or in any way related to my employment with the Company,or its affiliates, or the termination of that employment; (b) all claimsrelated to my compensation or benefits, including salary, bonuses, commissions,vacation pay, expense reimbursements, severance pay, fringe benefits, stock,stock options, or any other ownership interests in the Company, or itsaffiliates; (c) all claims for breach of contract, wrongful termination,and breach of the implied covenant of good faith and fair dealing; (d) alltort claims, including claims for fraud, defamation, emotional distress, anddischarge in violation of public policy; and (e) all federal, state, andlocal statutory claims, including claims for discrimination, harassment,retaliation, attorneys’ fees, or other claims arising under the federal CivilRights Act of 1964 (as amended), the federal Americans with Disabilities Act of1990 (as amended), the federal Age Discrimination in Employment Act (asamended) (“***ADEA***”), the federal EmployeeRetirement Income Security Act of 1974 (as amended), and the California FairEmployment and Housing Act (as amended); *p**rovided, however,* that nothing in this paragraph shall beconstrued in any way to release the Company or its affiliates from itsobligation to indemnify me pursuant to agreement or applicable law.

 

I acknowledge that I have read and understand Section 1542 of theCalifornia Civil Code which reads as follows: **“A generalrelease does not extend to claims which the creditor does not know or suspectto exist in his favor at the time of executing the release, which if known byhim must have materially affected his settlement with the debtor.”**  I hereby expressly waive and relinquish allrights

 

1

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andbenefits under that section and any law of any jurisdiction of similar effectwith respect to my release of any claims hereunder.

 

I acknowledge that to become effective, I must sign and returnthis Release to the Company so that it is received not later than fourteen (14)days following the date it is provided to me.

 
|   | **EMPLOYEE** |
|--------|--------------|
|   |         |
|   | Name:        |   |
|   |         |   |
|   | Date:        |   |

 

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