As filed with the Securities and Exchange Commission on April 4, 2019

Registration No. 333-            

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-8

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

ALTIMMUNE, INC.

(Exact name of Registrant as specified in its charter)

ALTIMMUNE, INC. 2019 EMPLOYEE STOCK PURCHASE PLAN

(Full Title of the Plan)

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act.  ☐

CALCULATION OF REGISTRATION FEE

PART I

INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS

The information specified in Items 1 and 2 of Part I of the Form S-8 is omitted from this Registration Statement in accordance with the provisions of Rule 428 under the Securities Act and the introductory note to Part I of Form S-8. The documents containing the information specified in Part I will be delivered to the participants in the Plan covered by this Registration Statement as required by Rule 428(b)(1) under the Securities Act.

PART II

INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

The Company hereby incorporates by reference into this Registration Statement the following documents previously filed with the Securities and Exchange Commission (the “Commission”):

All documents filed by the Company pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Exchange Act, subsequent to the effective date of this Registration Statement and prior to the filing of a post-effective amendment to this Registration Statement indicating that all securities offered hereby have been sold or deregistering all securities then remaining unsold, shall be deemed to be incorporated by reference herein and to be part hereof from the date of filing of such documents. In no event, however, will any information that the Registrant discloses under Item 2.02 or Item 7.01 of any Current Report on Form 8-K that the Registrant may from time to time furnish to the Commission be incorporated by reference into, or otherwise become a part of, this Registration Statement, unless otherwise indicated therein. Any statement contained in any document incorporated or deemed to be incorporated by reference herein shall be deemed to be modified or superseded for purposes of this Registration Statement to the extent that a statement contained herein or in any other subsequently filed document which also is or is deemed to be incorporated by reference herein modifies or supersedes such statement. Any such statement so modified or superseded shall not be deemed to constitute a part of this Registration Statement, except as so modified or superseded.

Not applicable.

Not applicable.

Section 145 of the Delaware General Corporation Law authorizes a court to award, or a corporation’s board of directors to grant, indemnity to directors and officers in terms sufficiently broad to permit such indemnification under certain circumstances for liabilities, including reimbursement for expenses incurred, arising under the Securities Act.

The Company’s amended and restated certificate of incorporation and amended and restated bylaws provide that the Registrant will indemnify its directors and officers, and may indemnify its employees and other agents, to the fullest extent permitted by the Delaware General Corporation Law. However, Delaware law prohibits the Company’s certificate of incorporation from limiting the liability of the Company’s directors for the following:

The Company has entered into agreements to indemnify each of its directors and officers. These agreements provide for the indemnification of such persons for all reasonable expenses and liabilities incurred in connection with any action or proceeding brought against them by reason of the fact that they are or were serving in such capacity.

The Company may maintain insurance policies that indemnify its directors and officers against various liabilities arising under the Securities Act and the Exchange Act that might be incurred by any director or officer in his capacity as such. The Company has obtained director and officer liability insurance to cover liabilities directors and officers may incur in connection with their services to the Company.

Not applicable.

(a) The undersigned Registrant hereby undertakes:

(1) To file, during any period in which offers or sales are being made, a post-effective amendment to this Registration Statement:

(i) to include any prospectus required by Section 10(a)(3) of the Securities Act;

(ii) to reflect in the prospectus any facts or events arising after the effective date of the Registration Statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in the Registration Statement. Notwithstanding the foregoing, any increase or decrease in volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the Commission pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than a 20 percent change in the maximum aggregate offering price set forth in the “Calculation of Registration Fee” table in the effective Registration Statement;

(iii) to include any material information with respect to the plan of distribution not previously disclosed in the Registration Statement or any material change to such information in the Registration Statement;

Provided, however, that (A) paragraphs (a)(1)(i) and (a)(1)(ii) do not apply if the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed with or furnished to the Commission by the Registrant pursuant to Section 13 or Section 15(d) of the Exchange Act that are incorporated by reference in the Registration Statement.

(2) That, for the purpose of determining any liability under the Securities Act, each such post-effective amendment shall be deemed to be a new Registration Statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(3) To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering.

(b) The undersigned Registrant hereby undertakes that, for purposes of determining any liability under the Securities Act, each filing of the Registrant’s annual report pursuant to Section 13(a) or 15(d) of the Exchange Act that is incorporated by reference in the Registration Statement shall be deemed to be a new Registration Statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(h) Insofar as indemnification for liabilities arising under the Securities Act may be permitted to directors, officers and controlling persons of the Registrant pursuant to the foregoing provisions, or otherwise, the Registrant has been advised that in the opinion of the Commission such indemnification is against public policy as expressed in the Securities Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the Registrant of expenses incurred or paid by a director, officer or controlling person of the Registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the Registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Securities Act and will be governed by the final adjudication of such issue.

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, the Registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-8 and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Gaithersburg, State of Maryland, on April 4, 2019.

POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS that each person whose signature appears below hereby constitutes and appoints Vipin K. Garg, William Brown, and Ori Solomon, or any of them individually, such person’s true and lawful attorneys-in-fact and agents, with full power of substitution and resubstitution, for and in such person’s name, place and stead, in the capacities indicated below, to sign this Registration Statement on Form S-8 of Altimmune, Inc. and any and all amendments (including post-effective amendments) thereto, and to file or cause to be filed the same, with all exhibits thereto, and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorneys-in-fact and agents, and each of them, full power and authority to do and perform each and every act and thing requisite and necessary to be done in connection therewith, as fully to all intents and purposes as such person might, or could, do in person, hereby ratifying and confirming all that said attorneys-in-fact and agents, and each of them, or his or her substitute or substitutes, may lawfully do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Act of 1933, this Registration Statement has been signed by the following persons in the capacities and on the date indicated.

Exhibit 5.1

[Letterhead of Morrison & Foerster LLP]

April 4, 2019

Board of Directors

Altimmune, Inc.

910 Clopper Road, Suite 201S

Gaithersburg, Maryland 20878

Re: Registration Statement on Form S-8

Ladies and Gentlemen:

We have acted as counsel to Altimmune, Inc., a Delaware corporation (the “Company”), in connection with the preparation and filing of its registration statement on Form S-8 (the “Registration Statement”), filed with the Securities and Exchange Commission (the “Commission”) under the Securities Act of 1933, as amended (the “Securities Act”), relating to the proposed issuance and sale of up to 403,500 shares (the “Shares”) of the Company’s common stock, par value $0.001 per share, all of which may be issued pursuant to awards under the Company’s 2019 Employee Stock Purchase Plan (the “Plan”).

As counsel for the Company, we have examined the Registration Statement and originals or copies, certified or otherwise identified to our satisfaction, of such agreements, instruments, documents, certificates and records as we have deemed relevant and necessary for the basis of our opinions hereinafter expressed. In such examination, we have assumed: (i) the authenticity of original documents and the genuineness of all signatures; (ii) the conformity to the originals of all documents submitted to us as copies; (iii) the truth, accuracy and completeness of the information, representations and warranties contained in the agreements, instruments, documents, certificates and records that we have reviewed; and (iv) the legal capacity of all natural persons. As to all matters of fact, we have relied on the representations and statements of fact made in the documents so reviewed, and we have not independently established or verified the facts so relied on. This opinion letter is given, and all statements herein are made, in the context of the foregoing.

Based upon, subject to and limited by the foregoing, we are of the opinion that following (i) effectiveness of the Registration Statement, (ii) issuance of the Shares pursuant to the terms of the Plan and (iii) receipt by the Company of the consideration for the Shares specified in the applicable resolutions of the Board of Directors or a duly authorized committee thereof and the Plan, the Shares will be validly issued, fully paid and nonassessable.

This opinion letter is based as to matters of law solely on the Delaware General Corporation Law, as amended. We express no opinion herein as to any other laws, statutes, ordinances, rules, or regulations. As used herein, the term “Delaware General Corporation Law, as amended” includes the statutory provisions contained therein, all applicable provisions of the Delaware Constitution and reported judicial decisions interpreting these laws.

Board of Directors

Altimmune, Inc.

April 4, 2019

Page 2

This opinion letter has been prepared for your use in connection with the Registration Statement. We assume no obligation to advise you of any changes in the foregoing subsequent to the effective date of the Registration Statement.

We hereby consent to the filing of this opinion letter as Exhibit 5.1 to the Registration Statement with the Commission and to reference to us wherever appearing in the Registration Statement. In giving such consent, we do not hereby admit that we are acting within the category of persons whose consent is required under Section 7 of the Securities Act or the rules or regulations of the Commission thereunder.

EXHIBIT 23.2

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We consent to the incorporation by reference in the Registration Statement (Form S-8) pertaining to the 2019 Employee Stock Purchase Plan of Altimmune, Inc. of our report dated April 1, 2019, with respect to the consolidated financial statements of Altimmune, Inc. included in its Annual Report (Form 10-K) for the year ended December 31, 2018, filed with the Securities and Exchange Commission.

/s/ Ernst & Young LLP

Baltimore, MD

April 4, 2019

Exhibit 99.1

Final Version

Adopted March 29, 2019

ALTIMMUNE, INC.

2019 EMPLOYEE STOCK PURCHASE PLAN

The following constitute the provisions of the 2019 Employee Stock Purchase Plan of Altimmune, Inc.

1. Purpose. The purpose of the Plan is to provide Employees of the and its Designated Parents or Subsidiaries with an opportunity to purchase Common Stock (as defined below) of the Company through accumulated payroll deductions. It is the intention of the Company to have the Plan qualify as an “employee stock purchase plan” under Section 423 of the Code. The provisions of the Plan, accordingly, shall be construed so as to extend and limit participation in a manner consistent with the requirements of Section 423 of the Code.

2. Definitions. As used herein, the following definitions shall apply:

(a) “Acquisition Event” means (i) a merger or consolidation in which the Company is not the surviving entity, (ii) any transaction that results in the acquisition of all or substantially all of the Company’s outstanding Common Stock by a single person or entity or by a group of persons or entities acting in concert or (iii) the sale or transfer of all or substantially all of the Company’s assets.

(b) “Administrator” means either the Board or a committee of the Board that is responsible for the administration of the Plan as is designated from time to time by resolution of the Board.

(c) “Applicable Laws” means the legal requirements relating to the administration of employee stock purchase plans, if any, under applicable provisions of federal securities laws, state corporate and securities laws, the Code and the applicable regulations thereunder, the rules of any applicable stock exchange or national market system, and the rules of any foreign jurisdiction applicable to participation in the Plan by residents therein.

(d) “Board” means the Board of Directors of the Company.

(e) “Code” means the Internal Revenue Code of 1986, as amended, and the regulations thereunder.

(f) “Common Stock” means the common stock of the Company, par value $0.001 per share.

(g) “Company” means Altimmune, Inc., a Delaware corporation, and its successors by operation of law.

(h) “Compensation” means an Employee’s base salary from the Company or one or more Designated Parents or Subsidiaries, including such amounts of base salary as are deferred by the Employee (i) under a qualified cash or deferred arrangement described in Section 401(k) of the Code or (ii) to a plan qualified under Section 125 of the Code. Compensation does not include overtime, bonuses, annual awards, other incentive payments, reimbursements or other expense allowances, fringe benefits (cash or noncash), moving expenses, deferred

compensation, contributions (other than contributions described in the first sentence) made on the Employee’s behalf by the Company or one or more Designated Parents or Subsidiaries under any employee benefit or welfare plan now or hereafter established, and any other payments not specifically referenced in the first sentence.

(i) “Designated Parents or Subsidiaries” means the Parents or Subsidiaries which have been designated by the Administrator from time to time as eligible to participate in the Plan.

(j) “Effective Date” means March 29, 2019. However, if any Parent or Subsidiary becomes a Designated Parent or Subsidiary after such date, then the Administrator, in its discretion, shall designate a separate Effective Date with respect to the employee-participants of such Designated Parent or Subsidiary.

(k) “Employee” means any individual, including an officer or director, who is an employee of the Company or a Designated Parent or Subsidiary for purposes of Section 423 of the Code. For purposes of the Plan, the employment relationship shall be treated as continuing intact while the individual is on sick leave or other leave of absence approved by the individual’s employer. Where the period of leave exceeds three months and the individual’s right to reemployment is not guaranteed either by statute or by contract, the employment relationship will be deemed to have terminated on the day that is three months and one day following the start of such leave, for purposes of determining eligibility to participate in the Plan.

(l) “Exchange Act” means the Securities Exchange Act of 1934, as amended.

(m) “Exercise Date” means the last day of each Purchase Period.

(n) “Fair Market Value” means, as of any date, the value of Common Stock determined as follows:

(i) If the Common Stock is listed on one or more established stock exchanges, including without limitation The Nasdaq Global Select Market, The Nasdaq Global Market or The Nasdaq Capital Market of the Nasdaq Stock Market, LLC or The New York Stock Exchange, its Fair Market Value shall be the closing sales price for such stock (or the closing bid, if no sales were reported) as quoted on the principal exchange or system on which the Common Stock is listed (as determined by the Administrator) on the date of determination (or, if no closing sales price or closing bid was reported on that date, as applicable, on the last trading date such closing sales price or closing bid was reported), as reported in The Wall Street Journal or such other source as the Administrator deems reliable;

(ii) If the Common Stock is regularly quoted on an automated quotation system (including the OTC Bulletin Board) or by a recognized securities dealer, but selling prices are not reported, its Fair Market Value shall be the mean between the high bid and low asked prices for the Common Stock on the date of determination (or, if no such prices were reported on that date, on the last date such prices were reported), as reported in The Wall Street Journal or such other source as the Administrator deems reliable; or

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(iii) In the absence of an established market for the Common Stock of the type described in (i) and (ii), above, its Fair Market Value thereof shall be determined by the Administrator in good faith.

(o) “New Exercise Date” has the meaning set forth in Section 18(b).

(p) “Offering” means an offer under the Plan of an Option that may be exercised during an Offering Period. For purposes of the Plan, all Employees eligible to participate pursuant to Section 3 will be deemed to participate in the same Offering unless the Administrator otherwise determines that Employees of the Company or one or more Designated Parents or Subsidiaries will be deemed to participate in separate Offerings, in which case the Offerings will be considered separate even if the dates of each such Offering are identical and the provisions of the Plan will separately apply to each Offering. To the extent permitted by Section 1.423-2(a)(1) of the Treasury regulations issued under Section 423 of the Code, the terms of each Offering need not be identical provided that the terms of the Plan and the Offering together satisfy Sections 1.423-2(a)(2) and (a)(3) of such Treasury regulations.

(q) “Offering Date” means the first day of each Offering Period.

(r) “Offering Period” means an Offering Period established pursuant to Section 4.

(s) “Option” means, with respect to each Offering Period, a right to purchase shares of Common Stock on the Exercise Date for such Offering Period in accordance with the terms and conditions of the Plan.

(t) “Parent” means a “parent corporation” of the Company, whether now or hereafter existing, as defined in Section 424(e) of the Code.

(u) “Participant” means an Employee of the Company or Designated Parent or Subsidiary who has enrolled in the Plan as set forth in Section 5(a).

(v) “Plan” means this 2019 Employee Stock Purchase Plan.

(w) “Purchase Period” means a period of six months, commencing on February 1 and August 1 of each year and terminating on the next following July 31 or January 31, respectively.

(x) “Purchase Price” means an amount equal to the lower of (i) 85% (or such greater percentage as designated by the Administrator) of the Fair Market Value of a share of Common Stock on the Offering Date or (ii) 85% (or such greater percentage as designated by the Administrator) of the Fair Market Value of a share of Common Stock on the Exercise Date.

(y) “Reserves” means, as of any date, the sum of (i) the number of shares of Common Stock covered by each then outstanding Option under the Plan which has not yet been exercised and (ii) the number of shares of Common Stock which have been authorized for issuance under the Plan but not then subject to an outstanding Option.

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(z) “Subsidiary” means a “subsidiary corporation” of the Company, whether now or hereafter existing, as defined in Section 424(f) of the Code.

3. Eligibility.

(a) General. Subject to the further limitations in Sections 3(b) and 3(c), any individual who is an Employee on a given Offering Date shall be eligible to participate in the Plan for the Offering Period commencing with such Offering Date. No individual who is not an Employee shall be eligible to participate in the Plan.

(b) Limitations on Grant and Accrual. Any provisions of the Plan to the contrary notwithstanding, no Employee shall be granted an Option under the Plan (i) if, immediately after the grant, such Employee (taking into account stock owned by any other person whose stock would be attributed to such Employee pursuant to Section 424(d) of the Code) would own stock and/or hold outstanding options to purchase stock possessing 5% or more of the total combined voting power or value of all classes of stock of the Company or of any Parent or Subsidiary or (ii) which permits the Employee’s rights to purchase stock under all employee stock purchase plans of the Company and its Parents or Subsidiaries to accrue at a rate which exceeds $25,000 worth of stock (determined at the Fair Market Value of the shares at the time such Option is granted) for each calendar year in which such Option is outstanding at any time. The determination of the accrual of the right to purchase stock shall be made in accordance with Section 423(b)(8) of the Code.

(c) Other Limits on Eligibility. Notwithstanding Section 3(a), unless otherwise determined prior to the applicable Offer Date, the following Employees shall not be eligible to participate in the Plan for any relevant Offering Period: (i) Employees whose customary employment is 20 hours or less per week; (ii) Employees whose customary employment is for not more than five months in any calendar year; (iii) Employees who have not been employed for such continuous period preceding the Offering Date as the Administrator may require, but in no event shall the required period of continuous employment be equal to or greater than two years; and (iv) Employees who are citizens or residents of a non-U.S. jurisdiction (without regard to whether they are also citizens of the United States or resident aliens (within the meaning of Section 7701(b)(1)(A) of the Code)) if their participation is prohibited under the laws of the applicable non-U.S. jurisdiction or if complying with the laws of the applicable non-U.S. jurisdiction would cause the Plan or an Offering to violate Section 423 of the Code.

4. Offering Periods.

(a) The Plan shall be implemented through overlapping or consecutive Offering Periods until such time as (i) the maximum number of shares of Common Stock available for issuance under the Plan shall have been purchased or (ii) the Plan shall have been sooner terminated in accordance with Section 19. The maximum duration of an Offering Period shall be 27 months. Initially, unless otherwise determined by the Administrator, the Plan shall be implemented through consecutive Offering Periods of six months’ duration commencing each February 1 and August 1 following the Effective Date.

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(b) A Participant shall be granted a separate Option for each Offering Period in which he or she participates. The Option shall be granted on the Offering Date and shall be automatically exercised on the Exercise Date ending within the Offering Period.

(c) Except as specifically provided herein, the acquisition of Common Stock through participation in the Plan for any Offering Period shall neither limit nor require the acquisition of Common Stock by a Participant in any subsequent Offering Period.

5. Participation.

(a) An eligible Employee may become a Participant in the Plan by submitting an authorization of payroll deduction (using such form or method (including electronic forms) as the Administrator may designate from time to time) as of a date in advance of the Offering Date for the Offering Period in which such participation will commence, as required by the Administrator for all eligible Employees with respect to a given Offering Period.

(b) Payroll deductions for a Participant shall commence with the first partial or full payroll period beginning on the Offering Date and shall end on the last complete payroll period during the Offering Period, unless sooner terminated by the Participant as provided in Section 10.

6. Payroll Deductions.

(a) At the time a Participant enrolls in the Plan, the Participant shall elect to have payroll deductions made during the Offering Period in amounts between 1% and not exceeding 10% of the Compensation which the Participant receives during the Offering Period.

(b) All payroll deductions made for a Participant shall be credited to the Participant’s account under the Plan and will be withheld in whole percentages only. A Participant may not make any additional payments into such account.

(c) A Participant may discontinue participation in the Plan as provided in Section 10, or may increase or decrease the rate of payroll deductions during the Offering Period by submitting notice of a change of status (using such form or method (including electronic forms) as the Administrator may designate from time to time) authorizing an increase or decrease in the payroll deduction rate. Any increase or decrease in the rate of a Participant’s payroll deductions shall be effective as soon as administratively practicable following the date of the request. A Participant’s payroll deduction authorization (as modified by any change of status notice) shall remain in effect for successive Offering Periods unless terminated as provided in Section 10. The Administrator shall be authorized to limit the number of payroll deduction rate changes during any Offering Period.

(d) Notwithstanding the foregoing, to the extent necessary to comply with Section 423(b)(8) of the Code and Section 3(b), a Participant’s payroll deductions shall be decreased to 0%. Payroll deductions shall recommence at the rate provided in such Participant’s payroll deduction authorization, as amended, when permitted under Section 423(b)(8) of the Code and Section 3(b), unless such participation is sooner terminated by the Participant as provided in Section 10.

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7. Grant of Option. On the Offering Date, each Participant shall be granted an Option to purchase (at the applicable Purchase Price) shares of Common Stock; provided that such Option shall be subject to (i) the limitations set forth in Sections 3(b), 6 and 12 and (ii) such other terms and conditions (applied on a uniform and nondiscriminatory basis) as the Administrator shall determine from time to time. Exercise of the Option shall occur as provided in Section 8, unless the Participant has withdrawn pursuant to Section 10, and the Option, to the extent not exercised, shall expire on the last day of the Offering Period with respect to which the Option was granted.

8. Exercise of Option. Unless a Participant withdraws from the Plan as provided in Section 10, the Participant’s Option for the purchase of shares of Common Stock will be exercised automatically on the Exercise Date, by applying the accumulated payroll deductions in the Participant’s account to purchase the number of full shares subject to the Option by dividing the Participant’s payroll deductions accumulated prior to the Exercise Date and retained in the Participant’s account as of the Exercise Date by the applicable Purchase Price. No fractional shares will be purchased; any payroll deductions accumulated in a Participant’s account which are not sufficient to purchase a full share shall be carried over to the next Purchase Period or Offering Period, whichever applies, or returned to the Participant, if the Participant withdraws from the Plan. In addition, any amount remaining in a Participant’s account following the purchase of shares on the Exercise Date due to the application of Section 423(b)(8) of the Code or Section 7, shall be returned to the Participant and shall not be carried over to the next Offering Period or Purchase Period. During a Participant’s lifetime, a Participant’s Option to purchase shares hereunder is exercisable only by the Participant.

9. Delivery. Upon receipt of a request from a Participant after each Exercise Date on which a purchase of shares occurs, the Company shall arrange for the delivery to such Participant, as soon as administratively practicable, of the shares purchased upon exercise of the Participant’s Option.

10. Withdrawal; Termination of Employment.

(a) A Participant may, by giving notice to the Company (using such form or method (including electronic forms) as the Administrator may designate from time to time), either (i) withdraw all but not less than all the payroll deductions credited to the Participant’s account and not yet used to exercise the Participant’s Option under the Plan or (ii) terminate future payroll deductions, but allow accumulated payroll deductions to be used to exercise the Participant’s Option under the Plan at any time. If the Participant elects withdrawal alternative (i) described above, all of the Participant’s payroll deductions credited to the Participant’s account will be paid to the Participant as soon as administratively practicable after receipt of notice of withdrawal, the Participant’s Option for the Offering Period will be automatically terminated, and no further payroll deductions for the purchase of shares will be made during the Offering Period. If the Participant elects withdrawal alternative (ii) described above, no further payroll deductions for the purchase of shares will be made during the Offering Period, all of the Participant’s payroll deductions credited to the Participant’s account will be applied to the exercise of the Participant’s Option on the next Exercise Date (subject to Sections 3(b), 6, 7 and 12), and after such Exercise Date, the Participant’s Option for the Offering Period will be automatically terminated and all remaining accumulated payroll deduction amounts shall be

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returned to the Participant. If a Participant withdraws from an Offering Period, payroll deductions will not resume at the beginning of the succeeding Offering Period unless the Participant enrolls in such succeeding Offering Period. The Administrator may, in its discretion and on a uniform and nondiscriminatory basis, specify procedures for withdrawal.

(b) Upon termination of a Participant’s employment relationship (as described in Section 2(k)) prior to the next scheduled Exercise Date, the payroll deductions credited to such Participant’s account during the Offering Period but not yet used to exercise the Option will be returned to such Participant or, in the case of his or her death, to the person or persons entitled thereto under Section 14, and such Participant’s Option will be automatically terminated without exercise of any portion of such Option.

11. Interest. No interest shall accrue on the payroll deductions credited to a Participant’s account under the Plan.

12. Stock.

(a) The maximum number of shares of Common Stock which shall be made available for sale under the Plan shall be 403,500 shares, subject to adjustment upon changes in capitalization of the Company as provided in Section 18. If the Administrator determines that on a given Exercise Date the number of shares with respect to which Options are to be exercised may exceed (i) the number of shares then available for sale under the Plan or (ii) the number of shares available for sale under the Plan on the Offering Date(s) of one or more of the Offering Periods in which such Exercise Date is to occur, the Administrator may make an allocation of the shares remaining available for purchase on such Offering Dates or Exercise Date, as applicable, and shall either continue the Offering Period then in effect or terminate any one or more Offering Periods then in effect pursuant to Section 19. Such allocation method shall be “bottom up,” with the result that all Option exercises for one share shall be satisfied first, followed by all exercises for two shares, and so on, until all available shares have been exhausted. Any amount remaining in a Participant’s payroll account following such allocation shall be returned to the Participant and shall not be carried over to any future Purchase Period or Offering Period, as determined by the Administrator.

(b) A Participant will have no interest or voting right in shares covered by the Participant’s Option until such shares are actually purchased on the Participant’s behalf in accordance with the applicable provisions of the Plan. No adjustment shall be made for dividends, distributions or other rights for which the record date is prior to the date of such purchase.

(c) Shares to be delivered to a Participant under the Plan will be registered in the name of the Participant.

13. Administration. The Plan shall be administered by the Administrator, which shall have full and exclusive discretionary authority to construe, interpret and apply the terms of the Plan, to determine eligibility, to adjudicate all disputed claims filed under the Plan, and to designate separate Offerings for the eligible Employees of the Company and one or more Designated Parents or Subsidiaries, in which case the Offerings will be considered separate even

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if the dates of each such Offering are identical and the provisions of the Plan will separately apply to each Offering. Every finding, decision and determination made by the Administrator shall, to the full extent permitted by Applicable Law, be final and binding upon all persons. Subject to Applicable Laws, no member of the Board or committee of the Board (or its delegates) shall be liable for any good faith action or determination made in connection with the operation, administration or interpretation of the Plan. In the performance of its responsibilities with respect to the Plan, the Administrator may rely upon, and no member of the Board or committee of the Board (or its delegates) shall be liable for any action taken or not taken in reliance upon, information and/or advice furnished by the Company’s officers or employees, the Company’s accountants, the Company’s counsel and any other party that a committee of the Board deems necessary. To the extent not prohibited by Applicable Laws, the Administrator may, from time to time, delegate some or all of its authority under the Plan to a subcommittee or subcommittees or other persons or groups of persons as it deems necessary, appropriate or advisable under conditions or limitations that it may set at or after the time of the delegation. For purposes of the Plan, reference to the Administrator shall be deemed to refer to any subcommittee, subcommittees, or other persons or groups of persons to whom such committee delegates authority pursuant to this Section 13.

14. Designation of Beneficiary.

(a) Each Participant will file a designation (using such form or method (including electronic forms) as the Administrator may designate from time to time) of a beneficiary who is to receive any shares and cash, if any, from the Participant’s account under the Plan in the event of such Participant’s death. If a Participant is married and the designated beneficiary is not the spouse, spousal consent shall be required for such designation to be effective.

(b) Such designation of beneficiary may be changed by the Participant (and the Participant’s spouse, if any) at any time by written notice. In the event of the death of a Participant and in the absence of a beneficiary validly designated under the Plan who is living (or in existence) at the time of such Participant’s death, the Company shall deliver such shares and/or cash to the executor or administrator of the estate of the Participant, or if no such executor or administrator has been appointed (to the knowledge of the Administrator), the Administrator shall deliver such shares and/or cash to the spouse (or domestic partner, as determined by the Administrator) of the Participant, or if no spouse (or domestic partner) is known to the Administrator, then to the issue of the Participant, such distribution to be made per stirpes (by right of representation), or if no issue are known to the Administrator, then to the heirs at law of the Participant determined in accordance with Section 27.

15. Transferability. No payroll deductions credited to a Participant’s account, Options granted hereunder, or any rights with regard to the exercise of an Option or to receive shares under the Plan may be assigned, transferred, pledged or otherwise disposed of in any way (other than by will, the laws of descent and distribution, or as provided in Section 14) by the Participant. Any such attempt at assignment, transfer, pledge or other disposition shall be without effect, except that the Administrator may, in its sole discretion, treat such act as an election to withdraw funds from an Offering Period in accordance with Section 10.

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16. Use of Funds All payroll deductions received or held by the Company under the Plan may be used by the Company for any corporate purpose, and the Company shall not be obligated to segregate such payroll deductions or hold them exclusively for the benefit of Participants. All payroll deductions received or held by the Company may be subject to the claims of the Company’s general creditors. Participants shall have the status of general unsecured creditors of the Company. Any amounts payable to Participants pursuant to the Plan shall be unfunded and unsecured obligations for all purposes, including, without limitation, Title I of the Employee Retirement Income Security Act of 1974, as amended. The Company shall retain at all times beneficial ownership of any investments which the Company may make to fulfill its payment obligations hereunder. Any investments or the creation or maintenance of any trust or any Participant account shall not create or constitute a trust or fiduciary relationship between the Administrator, the Company or any Designated Parent or Subsidiary and a Participant, or otherwise create any vested or beneficial interest in any Participant or the Participant’s creditors in any assets of the Company or a Designated Parent or Subsidiary. The Participants shall have no claim against the Company or any Designated Parent or Subsidiary for any changes in the value of any assets that may be invested or reinvested by the Company with respect to the Plan.

17. Reports. Individual accounts will be maintained for each Participant in the Plan. Statements of account will be given to Participants at least annually, which statements will set forth the amounts of payroll deductions, the Purchase Price, the number of shares purchased and the remaining cash balance, if any.

18. Adjustments Upon Changes in Capitalization; Acquisition Events.

(a) Adjustments Upon Changes in Capitalization. Subject to any required action by the stockholders of the Company, the Administrator, in order to prevent dilution or enlargement of the benefits or potential benefits intended to be made available under the Plan, will, in such manner as it may deem equitable, adjust the Reserves, the Purchase Price, the maximum number of shares that may be purchased in any Offering Period or Purchase Period, as well as any other terms that the Administrator determines require adjustment, for: (i) any increase or decrease in the number of issued shares of Common Stock resulting from a stock split, reverse stock split, stock dividend, combination or reclassification of the Common Stock; (ii) any other increase or decrease in the number of issued shares of Common Stock effected without receipt of consideration by the Company; or (iii) as the Administrator may determine in its discretion, any other transaction with respect to Common Stock, including a corporate merger, consolidation, acquisition of property or stock, separation (including a spin-off or other distribution of stock or property), reorganization, liquidation (whether partial or complete) or any similar transaction; provided, however, that conversion of any convertible securities of the Company shall not be deemed to have been “effected without receipt of consideration”. Such adjustment, if any, shall be made by the Administrator, and its determination shall be final, binding and conclusive on all persons. Except as the Administrator determines, no issuance by the Company of shares of stock of any class, or securities convertible into shares of stock of any class, shall affect, and no adjustment by reason hereof shall be made with respect to, the Reserves and the Purchase Price.

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(b) Acquisition Events. In the event of a proposed Acquisition Event, each Option under the Plan shall be assumed by the successor corporation or a parent or subsidiary of the successor corporation, unless the Administrator, in the exercise of its sole discretion and in lieu of such assumption, determines to shorten the Offering Period then in progress by setting a new Exercise Date (the “New Exercise Date”). If the Administrator shortens the Offering Period then in progress in lieu of assumption in the event of an Acquisition Event, the Administrator shall notify each Participant in writing at least 10 business days prior to the New Exercise Date, that the Exercise Date for the Participant’s Option has been changed to the New Exercise Date and that either:

(i) the Participant’s Option will be exercised automatically on the New Exercise Date, unless prior to such date the Participant has withdrawn from the Offering Period as provided in Section 10; or

(ii) the Company shall pay to the Participant on the New Exercise Date an amount in cash, cash equivalents, or property as determined by the Administrator that is equal to the excess, if any, of (i) the Fair Market Value of the shares subject to the Option over (ii) the Purchase Price due had the Participant’s Option been exercised automatically under Subsection (b)(1) above. In addition, all remaining accumulated payroll deduction amounts shall be returned to the Participant.

(c) For purposes of Section 18(b), an Option granted under the Plan shall be deemed to be assumed if, in connection with the Acquisition Event, the Option is replaced with a comparable option with respect to shares of capital stock of the successor corporation or Parent thereof. The determination of option comparability shall be made by the Administrator prior to the Acquisition Event, and its determination shall be final, binding and conclusive on all persons.

19. Amendment or Termination.

(a) The Administrator may at any time and for any reason terminate or amend the Plan. Except as provided in Section 18, no such termination can adversely affect Options previously granted; provided that the Plan or any one or more Offering Periods then in effect may be terminated by the Administrator on any Exercise Date or by the Administrator establishing a new Exercise Date with respect to any Offering Period and/or Purchase Period then in progress if the Administrator determines that the termination of the Plan or one or more Offering Periods is in the best interests of the Company and its stockholders. Except as provided in Section 18 and this Section 19, no amendment may make any change in any Option theretofore granted which adversely affects the rights of any Participant without the consent of affected Participants. To the extent necessary to comply with Section 423 of the Code (or any successor rule or provision or any other Applicable Law), the Company shall obtain stockholder approval of any amendment in such a manner and to such a degree as required.

(b) Without stockholder consent and without regard to whether any Participant rights may be considered to have been “adversely affected,” the Administrator shall be entitled to limit the frequency and/or number of changes in the amount withheld during Offering Periods, change the length of Purchase Periods within any Offering Period, determine the length of any future Offering Period, determine whether future Offering Periods shall be

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consecutive or overlapping, establish the exchange ratio applicable to amounts withheld in a currency other than U.S. dollars, establish or change Plan or per Participant limits on share purchases, establish additional terms, conditions, rules or procedures to accommodate the rules or laws of applicable foreign jurisdictions, permit payroll withholding in excess of the amount designated by a Participant in order to adjust for delays or mistakes in the Company’s processing of properly completed withholding elections, establish reasonable waiting and adjustment periods and/or accounting and crediting procedures to ensure that amounts applied toward the purchase of Common Stock for each Participant properly correspond with amounts withheld from the Participant’s Compensation, and establish such other limitations or procedures as the Administrator determines in its sole discretion are advisable and which are consistent with the Plan, in each case to the extent consistent with the requirements of Section 423 of the Code and other Applicable Laws.

20. Notices. All notices or other communications by a Participant to the Company under or in connection with the Plan shall be deemed to have been duly given when received in the form specified by the Administrator at the location, or by the person, designated by the Administrator for the receipt thereof.

21. Conditions Upon Issuance of Shares. Shares shall not be issued with respect to an Option unless the exercise of such Option and the issuance and delivery of such shares pursuant thereto shall comply with all Applicable Laws and shall be further subject to the approval of counsel for the Company with respect to such compliance. As a condition to the exercise of an Option, the Company may require the Participant to represent and warrant at the time of any such exercise that the shares are being purchased only for investment and without any present intention to sell or distribute such shares if, in the opinion of counsel for the Company, such a representation is required by any Applicable Laws or is otherwise advisable. In addition, no Options shall be exercised or shares issued hereunder before the Plan has been approved by stockholders of the Company as provided in Section 23.

22. Term of Plan. The Plan shall become effective upon the earlier to occur of its adoption by the Board or its approval by the stockholders of the Company. It shall continue in effect for a term of 10 years unless sooner terminated under Section 19.

23. Stockholder Approval. Continuance of the Plan shall be subject to approval by the stockholders of the Company within 12 months before or after the date the Plan is adopted. Such stockholder approval shall be obtained in the degree and manner required under Applicable Laws.

24. No Employment Rights. The Plan does not, directly or indirectly, create any right for the benefit of any employee or class of employees to purchase any shares under the Plan, or create in any employee or class of employees any right with respect to continuation of employment by the Company or a Designated Parent or Subsidiary, and it shall not be deemed to interfere in any way with such employer’s right to terminate, or otherwise modify, an employee’s employment at any time.

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25. No Effect on Retirement and Other Benefit Plans. Except as specifically provided in a retirement or other benefit plan of the Company or a Designated Parent or Subsidiary, participation in the Plan shall not be deemed compensation for purposes of computing benefits or contributions under any retirement plan of the Company or a Designated Parent or Subsidiary, and shall not affect any benefits under any other benefit plan of any kind or any benefit plan subsequently instituted under which the availability or amount of benefits is related to level of compensation. The Plan is not a “pension plan” or “welfare plan” under the Employee Retirement Income Security Act of 1974, as amended.

26. Effect of Plan. The provisions of the Plan shall, in accordance with their terms, be binding upon, and inure to the benefit of, all successors of each Participant, including, without limitation, such Participant’s estate and the executors, administrators or trustees thereof, heirs and legatees, and any receiver, trustee in bankruptcy or representative of creditors of such Participant.

27. Governing Law. The Plan and matters arising under or related to it shall be governed by and construed in accordance with the internal laws of the State of Delaware without giving effect to its principles of conflicts of laws. If any provision of the Plan is determined by a court of law to be illegal or unenforceable, the other provisions shall nevertheless remain effective and shall remain enforceable.

* * * * *

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