Exhibit 10.1

ARENA PHARMACEUTICALS, INC.

2006 LONG-TERM INCENTIVE PLAN, AS AMENDED

Arena Pharmaceuticals, Inc. (the “Company”), a Delaware corporation, hereby establishes and adopts the following 2006 Long-Term Incentive Plan (the “Plan”).

1. PURPOSE OF THE PLAN

The purpose of the Plan is to assist the Company and its Subsidiaries in attracting and retaining selected individuals to serve as directors, employees, consultants and/or advisors of the Company and its Subsidiaries who are expected to contribute to the Company’s success and to achieve long-term objectives which will inure to the benefit of all stockholders of the Company through the additional incentives inherent in the Awards hereunder.

2. DEFINITIONS

2.1. “ Award ” shall mean any Option, Stock Appreciation Right, Restricted Stock Award, Restricted Stock Unit Award, Performance Award or any other right, interest or option relating to Shares or other property (including cash) granted pursuant to the provisions of the Plan.

2.2. “ Award Agreement ” shall mean any written agreement, contract or other instrument or document evidencing any Award granted hereunder, including through an electronic medium.

2.3. “ Board ” shall mean the board of directors of the Company.

2.4. “ Code ” shall mean the Internal Revenue Code of 1986, as amended from time to time.

2.5. “ Committee ” shall mean the Compensation Committee of the Board or a subcommittee thereof formed by the Compensation Committee to act as the Committee hereunder. The Committee shall consist of no fewer than two Directors, each of whom is (i) a “Non-Employee Director” within the meaning of Rule 16b-3 of the Exchange Act, (ii) an “outside director” within the meaning of Section 162(m) of the Code, and (iii) an “independent director” for purpose of the rules and regulations of the NASDAQ Stock Market (or such other principal securities market on which the Shares are traded).

2.6. “ Covered Employee ” shall mean a “covered employee” within the meaning of Section 162(m) of the Code.

2.7. “ Director ” shall mean a non-employee member of the Board.

2.8. “ Dividend Equivalents ” shall have the meaning set forth in Section 12.5.

2.9. “ Employee ” shall mean any employee of the Company or any Subsidiary and any prospective employee conditioned upon, and effective not earlier than, such person becoming an

employee of the Company or any Subsidiary. Solely for purposes of the Plan, an Employee shall also mean any consultant or advisor who is a natural person and who provides services to the Company or any Subsidiary, so long as such person (i) renders bona fide services that are not in connection with the offer and sale of the Company’s securities in a capital-raising transaction and (ii) does not directly or indirectly promote or maintain a market for the Company’s securities.

2.10. “ Exchange Act ” shall mean the Securities Exchange Act of 1934, as amended.

2.11. “ Fair Market Value ” shall mean, with respect to any property other than Shares, the market value of such property determined by such methods or procedures as shall be established from time to time by the Committee. The Fair Market Value of Shares as of any date shall be the per Share closing price of the Shares as reported on the NASDAQ Stock Market on that date (or if there was no reported closing price on such date, on the last preceding date on which the closing price was reported) or, if the Company is not then listed on the NASDAQ Stock Market, on such other principal securities exchange on which the Shares are traded, and if the Company is not listed on the NASDAQ Stock Market or any other securities exchange, the Fair Market Value of Shares shall be determined by the Committee in its sole discretion using appropriate criteria.

2.12. “ Limitations ” shall have the meaning set forth in Section 10.5.

2.13. “ Option ” shall mean any right granted to a Participant under the Plan allowing such Participant to purchase Shares at such price or prices and during such period or periods as the Committee shall determine.

2.14. “ Participant ” shall mean an Employee or Director who is selected by the Committee to receive an Award under the Plan.

2.15. “ Payee ” shall have the meaning set forth in Section 13.1.

2.16. “ Performance Award ” shall mean any Award of Performance Shares or Performance Units granted pursuant to Article 9.

2.17. “ Performance Period ” shall mean that period established by the Committee at the time any Performance Award is granted or at any time thereafter during which any performance goals specified by the Committee with respect to such Award are to be measured.

2.18. “ Performance Share ” shall mean any grant pursuant to Article 9 of a unit valued by reference to a designated number of Shares, which value may be paid to the Participant by delivery of such property as the Committee shall determine, including cash, Shares, other property, or any combination thereof, upon achievement of such performance goals during the Performance Period as the Committee shall establish.

2.19. “ Performance Unit ” shall mean any grant pursuant to Section 9 of a unit valued by reference to a designated amount of property other than Shares (or cash), which value may be paid to the Participant by delivery of such property as the Committee shall determine, including cash, Shares, other property, or any combination thereof, upon achievement of such performance goals during the Performance Period as the Committee shall establish.

2.20. “ Permitted Assignee ” shall have the meaning set forth in Section 12.3.

2.21. “ Prior Plans ” shall mean, collectively, the Company’s Amended and Restated 1998 Equity Compensation Plan, Amended and Restated 2000 Equity Compensation Plan and the 2002 Equity Compensation Plan.

2.22. “ Restricted Stock ” shall mean any Share issued with the restriction that the holder may not sell, transfer, pledge or assign such Share and with such other restrictions as the Committee, in its sole discretion, may impose (including any restriction on the right to vote such Share and the right to receive any dividends), which restrictions may lapse separately or in combination at such time or times, in installments or otherwise, as the Committee may deem appropriate.

2.23. “ Restricted Stock Award ” shall have the meaning set forth in Section 7.1.

2.24. “ Restricted Stock Unit Award ” shall have the meaning set forth in Section 8.1.

2.25. “ Shares ” shall mean the shares of common stock, $0.0001 par value, of the Company.

2.26. “ Stock Appreciation Right ” shall mean the right granted to a Participant pursuant to Section 6.

2.27. “ Subsidiary ” shall mean any corporation (other than the Company) in an unbroken chain of corporations beginning with the Company if, at the relevant time, each of the corporations other than the last corporation in the unbroken chain owns stock possessing 50% or more of the total combined voting power of all classes of stock in one of the other corporations in the chain.

2.28. “ Substitute Awards ” shall mean Awards granted or Shares issued by the Company in assumption of, or in substitution or exchange for, awards previously granted, or the right or obligation to make future awards, in each case by a company acquired by the Company or any Subsidiary or with which the Company or any Subsidiary combines.

2.29. “ Vesting Period ” shall have the meaning set forth in Section 7.1.

3. SHARES SUBJECT TO THE PLAN

3.1 Number of Shares .

(a) Subject to adjustment as provided in Section 12.2, a total of 6,000,000 Shares shall be authorized for issuance under the Plan, as increased if applicable under this Section.

(b) If any Shares subject to an Award or to an award under the Prior Plans are forfeited, expire or otherwise terminate without issuance of such Shares, or any Award or award under the Prior Plans is settled for cash or otherwise does not result in the issuance of all or a portion of the Shares subject to such Award or award under the Prior Plans (including on

payment in Shares on the exercise of a Stock Appreciation Right), such Shares shall, to the extent of such forfeiture, expiration, termination, cash settlement or non-issuance, be available for issuance under the Plan.

(c) In the event that (i) any Award granted hereunder is exercised through the tendering of Shares (either actually or by attestation) or by the withholding of Shares by the Company, or (ii) withholding tax liabilities arising from any Award are satisfied by the tendering of Shares (either actually or by attestation) or by the withholding of Shares by the Company, then the Shares so tendered or withheld shall be available for issuance under the Plan. In the event that (i) any award granted under the Prior Plans is exercised through the tendering of Shares (either actually or by attestation) or by the withholding of Shares by the Company, or (ii) withholding tax liabilities arising from such award are satisfied by the tendering of Shares (either actually or by attestation) or by the withholding of Shares by the Company, then the Shares so tendered or withheld shall be available for issuance under the Plan.

(d) Shares issued under Substitute Awards shall not reduce the Shares authorized for issuance under the Plan or authorized for grant to a Participant under Section 10.5.

3.2. Character of Shares . Any Shares issued hereunder may consist, in whole or in part, of authorized and unissued shares, treasury shares or shares purchased in the open market or otherwise.

4. ELIGIBILITY AND ADMINISTRATION

4.1. Eligibility . Any Employee or Director shall be eligible to be selected as a Participant.

4.2. Administration . (a) The Plan shall be administered by the Committee. The Committee shall have full power and authority, subject to the provisions of the Plan and subject to such orders or resolutions not inconsistent with the provisions of the Plan as may from time to time be adopted by the Board, to: (i) select the Employees and Directors to whom Awards may from time to time be granted hereunder; (ii) determine the type or types of Awards, not inconsistent with the provisions of the Plan, to be granted to each Participant hereunder; (iii) determine the number of Shares to be covered by each Award granted hereunder; (iv) determine the terms and conditions, not inconsistent with the provisions of the Plan, of any Award granted hereunder (including the power to amend outstanding Awards); (v) determine whether, to what extent and under what circumstances Awards may be settled in cash, Shares or other property; (vi) determine whether, to what extent, and under what circumstances cash, Shares, other property and other amounts payable with respect to an Award made under the Plan shall be deferred either automatically or at the election of the Participant; (vii) determine whether, to what extent and under what circumstances any Award shall be canceled or suspended; (viii) interpret and administer the Plan and any instrument or agreement entered into under or in connection with the Plan, including any Award Agreement; (ix) correct any defect, supply any omission or reconcile any inconsistency in the Plan or any Award in the manner and to the extent that the Committee shall deem desirable to carry it into effect; (x) establish such rules and regulations and appoint such agents as it shall deem appropriate for the proper administration of the Plan; (xi) determine whether any Award, other than an Option or Stock

Appreciation Right, will have Dividend Equivalents; and (xii) make any other determination and take any other action that the Committee deems necessary or desirable for administration of the Plan.

(b) Decisions of the Committee shall be final, conclusive and binding on all persons or entities, including the Company, any Participant, and any Subsidiary. A majority of the members of the Committee may determine its actions, including fixing the time and place of its meetings.

(c) To the extent not inconsistent with applicable law, including Section 162(m) of the Code, or the rules and regulations of the NASDAQ Stock Market (or such other principal securities market on which the Shares are traded), the Committee may delegate to: (i) a committee of one or more members of the Board the authority to take action on behalf of the Committee under the Plan including the right to grant, cancel, suspend or amend Awards and (ii) one or more “executive officers” within the meaning of Rule 16a-1(f) of the Exchange Act or a committee of executive officers the right to grant Awards to Employees who are not Directors or executive officers of the Company, to the extent permitted by law.

(d) The Board in its discretion may ratify and approve actions taken by the Committee. In addition, to the extent not inconsistent with applicable law or the rules and regulations of the NASDAQ Stock Market or such other principal securities market on which the Shares are traded, the Board may take any action under the Plan that the Committee is authorized to take. In the event the Board takes such action references to the Committee hereunder shall be understood to refer to the Board.

5. OPTIONS

5.1. Grant of Options . Options may be granted hereunder to Participants either alone or in addition to other Awards granted under the Plan. Any Option shall be subject to the terms and conditions of this Article and to such additional terms and conditions, not inconsistent with the provisions of the Plan, as the Committee shall deem desirable.

5.2. Award Agreements . All Options granted pursuant to this Article shall be evidenced by a written Award Agreement in such form and containing such terms and conditions as the Committee shall determine which are not inconsistent with the provisions of the Plan. The terms of Options need not be the same with respect to each Participant. Granting an Option pursuant to the Plan shall impose no obligation on the recipient to exercise such Option. Any individual who is granted an Option pursuant to this Article may hold more than one Option granted pursuant to the Plan at the same time.

5.3. Option Price . Other than in connection with Substitute Awards, the option price per each Share purchasable under any Option granted pursuant to this Article shall not be less than 100% of the Fair Market Value of one Share on the date of grant of such Option. Other than pursuant to Section 12.2, the Committee shall not without the approval of the Company’s stockholders (a) lower the option price per Share of an Option after it is granted, (b) cancel an Option when the option price per Share exceeds the Fair Market Value of the underlying Shares in exchange for cash or another Award (other than in connection with Substitute Awards), and

(c) take any other action with respect to an Option that may be treated as a repricing under the rules and regulations of the NASDAQ Stock Market (or such other principal securities market on which the Shares are traded).

5.4. Option Term . The term of each Option shall be fixed by the Committee in its sole discretion; provided that no Option shall be exercisable after the expiration of ten (10) years from the date the Option is granted, except in the event of death or disability.

5.5. Exercise of Options . (a) Vested Options granted under the Plan may be exercised by the Participant or by a Permitted Assignee thereof (or by the Participant’s executors, administrators, guardian or legal representative, as may be provided in an Award Agreement) as to all or part of the Shares covered thereby, by the giving of notice of exercise to the Company or its designated agent, specifying the number of Shares to be purchased. The notice of exercise shall be in such form, made in such manner, and shall comply with such other requirements consistent with the provisions of the Plan as the Committee may from time to time prescribe.

(b) Unless otherwise provided in an Award Agreement, full payment of such purchase price shall be made at the time of exercise and shall be made (i) in cash or cash equivalents (including certified check or bank check or wire transfer of immediately available funds), (ii) by tendering previously acquired Shares (either actually or by attestation, valued at their then Fair Market Value), (iii) with the consent of the Committee, by delivery of other consideration (including, where permitted by law and the Committee, other Awards) having a Fair Market Value on the exercise date equal to the total purchase price, (iv) with the consent of the Committee, by withholding Shares otherwise issuable in connection with the exercise of the Option, (v) through any other method specified in an Award Agreement, or (vi) any combination of any of the foregoing. In no event may any Option granted hereunder be exercised for a fraction of a Share. No adjustment shall be made for cash dividends or other rights for which the record date is prior to the date of such issuance. Except under circumstances contemplated by Article 11 or as may be set forth in an Award Agreement with respect to (x) retirement, death or disability of a Participant, or (y) special circumstances determined by the Committee (such as the achievement of performance objectives), Options granted to employees of the Company or any Subsidiary will not be exercisable before the expiration of one year from the date the Option is granted (but may become exercisable pro rata over such time).

5.6. Incentive Stock Options. The Committee may grant Options intended to qualify as “incentive stock options” as defined in Section 422 of the Code, to any employee of the Company or any Subsidiary, subject to the requirements of Section 422 of the Code. Notwithstanding anything in Section 3.1 to the contrary and solely for the purposes of determining whether Shares are available for the grant of “incentive stock options” under the Plan, the maximum aggregate number of Shares that may be issued pursuant to “incentive stock options” granted under the Plan shall be 6,000,000 Shares.

6. STOCK APPRECIATION RIGHTS

6.1. Grant and Exercise . The Committee may provide Stock Appreciation Rights (a) in conjunction with all or part of any Option granted under the Plan or at any subsequent time during the term of such Option, (b) in conjunction with all or part of any Award (other than an Option) granted under the Plan or at any subsequent time during the term of such Award, or (c) without regard to any Option or other Award, in each case upon such terms and conditions as the Committee may establish in its sole discretion.

6.2. Terms and Conditions . Stock Appreciation Rights shall be subject to such terms and conditions, not inconsistent with the provisions of the Plan, as shall be determined from time to time by the Committee, including the following:

(a) Upon the exercise of a Stock Appreciation Right, the holder shall have the right to receive the excess of (i) the Fair Market Value of one Share on the date of exercise over (ii) the grant price of the right on the date of grant.

(b) Upon the exercise of a Stock Appreciation Right, the Committee shall determine in its sole discretion whether payment shall be made in cash, in whole Shares or other property, or any combination thereof.

(c) The provisions of Stock Appreciation Rights need not be the same with respect to each recipient.

(d) The Committee may impose such other conditions or restrictions on the terms of exercise and the grant price of any Stock Appreciation Right, as it shall deem appropriate. A Stock Appreciation Right shall have (i) a grant price per Share of not less than Fair Market Value of one Share on the date of grant (subject to the requirements of Section 409A of the Code with respect to a Stock Appreciation Right granted in conjunction with, but subsequent to, an Option), and (ii) a term not greater than ten (10) years. In addition to the foregoing, but subject to Section 12.2, the Committee shall not without the approval of the Company’s stockholders (x) lower the grant price per Share of any Stock Appreciation Right after it is granted, (y) cancel any Stock Appreciation Right when the grant price per Share exceeds the Fair Market Value of the underlying Shares in exchange for cash or another Award (other than in connection with Substitute Awards), and (z) take any other action with respect to any Stock Appreciation Right that may be treated as a repricing under the rules and regulations of the NASDAQ Stock Market (or such other principal securities market on which the Shares are traded).

(e) In no event may any Stock Appreciation Right granted hereunder be exercised for a fraction of a Share. No adjustment shall be made for cash dividends or other rights for which the record date is prior to the date of such issuance. Except under circumstances contemplated by Article 11 or as may be set forth in an Award Agreement with respect to (x) retirement, death or disability of a Participant, or (y) special circumstances determined by the Committee (such as the achievement of performance objectives), Stock Appreciation Rights granted to employees of the Company or any Subsidiary will not be exercisable before the

expiration of one year from the date the Stock Appreciation Right is granted (but may become exercisable pro rata over such time).

(f) The Committee may impose such other terms and conditions on Stock Appreciation Rights, not inconsistent with the Plan, as the Committee shall determine in its sole discretion.

7. RESTRICTED STOCK AWARDS

7.1. Grants . Awards of Restricted Stock may be issued hereunder to Participants either alone or in addition to other Awards granted under the Plan (a “Restricted Stock Award”), and such Restricted Stock Awards may also be available as a form of payment of Performance Awards and other earned cash-based incentive compensation. A Restricted Stock Award shall be subject to vesting restrictions imposed by the Committee covering a period of time specified by the Committee (the “Vesting Period”) consistent with the provisions herein. The Committee has absolute discretion to determine whether any consideration (other than services) is to be received by the Company or any Subsidiary as a condition precedent to the issuance of Restricted Stock.

7.2. Award Agreements . The terms of any Restricted Stock Award granted under the Plan shall be set forth in a written Award Agreement which shall contain provisions determined by the Committee and not inconsistent with the Plan. The terms of Restricted Stock Awards need not be the same with respect to each Participant.

7.3. Rights of Holders of Restricted Stock. Beginning on the date of grant of the Restricted Stock Award and subject to execution of the Award Agreement, the Participant shall become a stockholder of the Company with respect to all Shares subject to the Award Agreement and shall have all of the rights of a stockholder, including the right to vote such Shares and the right to receive distributions made with respect to such Shares; provided, however , that except as otherwise provided in an Award Agreement any Shares or any other property (other than cash) distributed as a dividend or otherwise with respect to any Restricted Stock as to which the restrictions have not yet lapsed shall be subject to the same restrictions as such Restricted Stock.

7.4 . Minimum Vesting Period. Except in the case of a Participant’s death, disability or retirement, or a Change in Control (as defined in Article 11), Restricted Stock Awards subject solely to the continued employment of employees of the Company or a Subsidiary shall have a Vesting Period of not less than three (3) years from date of grant (but permitting pro rata vesting over such time); provided that such minimum Vesting Period shall not be applicable to (i) grants of Substitute Awards to new hires to replace forfeited awards from a prior employer, or (ii) grants of Restricted Stock in payment of Performance Awards and other earned cash-based incentive compensation. The Committee may, in its sole discretion and subject to the limitations imposed under Section 162(m) of the Code and the regulations thereunder in the case of a Restricted Stock Award intended to comply with the performance-based exception under Code Section 162(m), grant Awards that do not comply with the minimum vesting periods of this Section 7.4 or Sections 8.3 or 9.3, or waive the forfeiture period and any other conditions set forth in any Award Agreement subject to such terms and conditions as the Committee shall deem appropriate; provided that, except in the case of a Participant’s death, disability or retirement, or a Change in Control, such Awards and waivers shall be limited to less than 10% of the Shares

authorized for issuance under the Plan. The minimum Vesting Period requirements of this Section shall not apply to Restricted Stock Awards granted to Directors or to any consultants or advisors who provide services to the Company or any Subsidiary.

8. RESTRICTED STOCK UNIT AWARDS

8.1. Grants . Other Awards of units having a value equal to an identical number of Shares (“Restricted Stock Unit Awards”) may be granted hereunder to Participants either alone or in addition to other Awards granted under the Plan. Restricted Stock Unit Awards shall also be available as a form of payment of other Awards granted under the Plan and other earned cash-based incentive compensation.

8.2. Award Agreements . The terms of Restricted Stock Unit Award granted under the Plan shall be set forth in a written Award Agreement which shall contain provisions determined by the Committee and not inconsistent with the Plan. The terms of such Awards need not be the same with respect to each Participant.

8.3. Vesting . Except in the case of a Participant’s death, disability or retirement, or a Change in Control (as defined in Article 11), Restricted Stock Unit Awards subject solely to the continued employment of employees of the Company or any Subsidiary shall be subject to a vesting period determined by the Committee of not less than three (3) years from date of grant (but permitting pro rata vesting over such time); provided, that such minimum vesting period shall not be applicable to (i) grants of Substitute Awards to new hires to replace forfeited awards from a prior employer, or (ii) grants of Restricted Stock Unit Awards in payment of Performance Awards and other earned cash-based incentive compensation. The Committee may, in its sole discretion and subject to the limitations imposed under Section 162(m) of the Code and the regulations thereunder in the case of a Restricted Stock Unit Award intended to comply with the performance-based exception under Code Section 162(m), grant Awards that do not comply with the minimum vesting periods of this Section 8.3 or Sections 7.4 or 9.3, or waive the forfeiture period and any other conditions set forth in any Award Agreement subject to such terms and conditions as the Committee shall deem appropriate; provided that, except in the case of a Participant’s death, disability or retirement, or a Change in Control, such Awards or waivers shall be limited to less than 10% of the Shares authorized for issuance under the Plan. The minimum vesting period requirements of this Section shall not apply to Restricted Stock Unit Awards granted to Directors or to any consultants or advisors who provide services to the Company or any Subsidiary.

8.4. Payment. Except as provided in Article 10 or as may be provided in an Award Agreement, Restricted Stock Unit Awards may be paid in cash, Shares, other property, or any combination thereof, in the sole discretion of the Committee. Restricted Stock Unit Awards may be paid in a lump sum or in installments or, in accordance with procedures established by the Committee, on a deferred basis subject to the requirements of Section 409A of the Code.

9. PERFORMANCE AWARDS

9.1. Grants . Performance Awards in the form of Performance Shares or Performance Units, as determined by the Committee in its sole discretion, may be granted hereunder to Participants, for no consideration or for such minimum consideration as may be required by applicable law, either alone or in addition to other Awards granted under the Plan. The performance goals to be achieved for each Performance Period shall be conclusively determined by the Committee and may be based upon the criteria set forth in Section 10.2.

9.2. Award Agreements. The terms of any Performance Award granted under the Plan shall be set forth in a written Award Agreement which shall contain provisions determined by the Committee and not inconsistent with the Plan, including whether such Awards shall have Dividend Equivalents. The terms of Performance Awards need not be the same with respect to each Participant.

9.3. Terms and Conditions. The performance criteria to be achieved during any Performance Period and the length of the Performance Period shall be determined by the Committee upon the grant of each Performance Award; provided, however, that a Performance Period shall not be less than 12 months. The amount of the Award to be distributed shall be conclusively determined by the Committee.

9.4. Payment. Except as provided in Article 11 or as may be provided in an Award Agreement, Performance Awards will be distributed only after the end of the relevant Performance Period. Performance Awards may be paid in cash, Shares, other property, or any combination thereof, in the sole discretion of the Committee. Performance Awards may be paid in a lump sum or in installments following the close of the Performance Period or, in accordance with procedures established by the Committee, on a deferred basis subject to the requirements of Section 409A of the Code.

10. CODE SECTION 162(m) PROVISIONS

10.1. Covered Employees . Notwithstanding any other provision of the Plan, if the Committee determines at the time a Restricted Stock Award, a Performance Award or an Restricted Stock Unit Award is granted to a Participant who is, or is likely to be, as of the end of the tax year in which the Company would claim a tax deduction in connection with such Award, a Covered Employee, then the Committee may provide that this Article 10 is applicable to such Award.

10.2. Performance Criteria. If the Committee determines that a Restricted Stock Award, a Performance Award or an Restricted Stock Unit Award is intended to be subject to this Article 10, the lapsing of restrictions thereon and the distribution of cash, Shares or other property pursuant thereto, as applicable, shall be subject to the achievement of one or more objective performance goals established by the Committee, which shall be based on the attainment of specified levels of one or any combination of the following: net sales; revenue; revenue or product revenue growth; operating income or loss (before or after taxes); pre- or after-tax income or loss (before or after allocation of corporate overhead and bonus); net earnings or loss; earnings or loss per share; net income or loss (before or after taxes); return on

equity; total stockholder return; return on assets or net assets; attainment of strategic and operational initiatives; appreciation in and/or maintenance of the price of the Shares or any other publicly-traded securities of the Company; market share; gross profits; earnings or losses (including earnings or losses before taxes, earnings or losses before interest and taxes, earnings or losses before interest, taxes and depreciation or earnings or losses before interest, taxes, depreciation and amortization); economic value-added models (or equivalent metrics); comparisons with various stock market indices; reductions in costs; cash flow or cash flow per share (before or after dividends); return on capital (including return on total capital or return on invested capital); cash flow return on investment; improvement in or attainment of expense levels or working capital levels; operating margin; gross margin; year-end cash; cash margin; debt reduction; stockholder’s equity; market share; achievement of drug development milestones; regulatory achievements including approval of a compound; progress of internal research or clinical programs; progress of partnered programs; implementation or completion of projects and processes; partner satisfaction; budget management; clinical progress including timely completion of clinical trials; submission of INDs and NDAs and other regulatory achievements; partner or collaborator achievements; internal controls, including those related to the Sarbanes-Oxley Act of 2002; research progress, including the development of programs; financing; investor relation, analysts and communication; inlicensing; and recruiting and maintaining personnel. Such performance goals also may be based solely by reference to the Company’s performance or the performance of a Subsidiary, division, business segment or business unit of the Company, or based upon the relative performance of other companies or upon comparisons of any of the indicators of performance relative to other companies. The Committee may also exclude charges related to an event or occurrence which the Committee determines should appropriately be excluded, including (a) restructurings, discontinued operations, extraordinary items, and other unusual or non-recurring charges, (b) an event either not directly related to the operations of the Company or not within the reasonable control of the Company’s management, or (c) the cumulative effects of tax or accounting changes in accordance with U.S. generally accepted accounting principles. Such performance goals shall be set by the Committee within the time period prescribed by, and shall otherwise comply with the requirements of, Section 162(m) of the Code, and the regulations thereunder.

10.3. Adjustments . Notwithstanding any provision of the Plan (other than Article 11), with respect to any Restricted Stock, Performance Award or Restricted Stock Unit Award that is subject to this Section 10, the Committee may adjust downwards, but not upwards, the amount payable pursuant to such Award, and the Committee may not waive the achievement of the applicable performance goals, except in the case of the death or disability of the Participant or as otherwise determined by the Committee in special circumstances.

10.4. Restrictions . The Committee shall have the power to impose such other restrictions on Awards subject to this Article as it may deem necessary or appropriate to ensure that such Awards satisfy all requirements for “performance-based compensation” within the meaning of Section 162(m) of the Code.

10.5. Limitations on Grants to Individual Participants . Subject to adjustment as provided in Section 12.2, no Participant may be granted (i) Options or Stock Appreciation Rights during any 36-month period with respect to more than 1,000,000 Shares or (ii) Restricted Stock, Performance Awards and/or Restricted Stock Unit Awards that are denominated in Shares in any 36-month period with respect to more than 500,000 Shares (the “Limitations”). In addition to

the foregoing, the maximum dollar value that may be granted by any Participant in any 12-month period with respect to Performance Awards is $5,000,000. If an Award is cancelled, the cancelled Award shall continue to be counted toward the applicable Limitations.

11. CHANGE IN CONTROL PROVISIONS

11.1. Impact on Certain Awards. The Committee, in its discretion, may determine that in the event of a Change in Control of the Company (as defined in Section 11.3) Options and Stock Appreciation Rights outstanding as of the date of the Change in Control shall be cancelled and terminated without payment therefore if the Fair Market Value of one Share as of the date of the Change in Control is less than the Option per Share option price or Stock Appreciation Right per Share grant price.

11.2. Assumption or Substitution of Certain Awards. (a) To the extent provided in an Award Agreement, in the event of a Change in Control of the Company in which the successor company assumes or substitutes for an Option, Stock Appreciation Right, Restricted Stock Award or Restricted Stock Unit Award, if a Participant’s employment with such successor company (or a subsidiary thereof) terminates within the time period following such Change in Control set forth in the Award Agreement (or prior thereto if applicable) and under the circumstances specified in the Award Agreement: (i) Options and Stock Appreciation Rights outstanding as of the date of such termination of employment will immediately vest, become fully exercisable, and may thereafter be exercised for the period of time set forth in the Award Agreement, (ii) restrictions and deferral limitations on Restricted Stock shall lapse and the Restricted Stock shall become free of all restrictions and limitations and become fully vested, and (iii) the restrictions and deferral limitations and other conditions applicable to any Restricted Stock Unit Awards or any other Awards shall lapse, and such Restricted Stock Unit Awards or such other Awards shall become free of all restrictions, limitations or conditions and become fully vested and transferable to the full extent of the original grant. For the purposes of this Section, an Option, Stock Appreciation Right, Restricted Stock Award or Restricted Stock Unit Award shall be considered assumed or substituted for if following the Change in Control the Award confers the right to purchase or receive, for each Share subject to the Option, Stock Appreciation Right, Restricted Stock Award or Restricted Stock Unit Award immediately prior to the Change in Control, the consideration (whether stock, cash or other securities or property) received in the transaction constituting a Change in Control by holders of Shares for each Share held on the effective date of such transaction (and if holders were offered a choice of consideration, the type of consideration chosen by the holders of a majority of the outstanding shares); provided, however, that if such consideration received in the transaction constituting a Change in Control is not solely common stock of the successor company, the Committee may, with the consent of the successor company, provide that the consideration to be received upon the exercise or vesting of an Option, Stock Appreciation Right, Restricted Stock Award or Restricted Stock Unit Award, for each Share subject thereto, will be solely common stock of the successor company substantially equal in fair market value to the per share consideration received by holders of Shares in the transaction constituting a Change in Control. The determination of such substantial equality of value of consideration shall be made by the Committee in its sole discretion and its determination shall be conclusive and binding.

(b) In the event of a Change in Control of the Company, to the extent that the successor company does not assume or substitute for an Option, Stock Appreciation Right, Restricted Stock Award, Restricted Stock Unit Award or Performance Award (unless otherwise provided in an Award Agreement), then immediately prior to the Change in Control: (i) those outstanding Options and Stock Appreciation Rights that are not assumed or substituted for shall immediately vest and become fully exercisable, (ii) restrictions and deferral limitations on Restricted Stock not assumed or substituted for shall lapse and the Restricted Stock shall become free of all restrictions and limitations and become fully vested, (iii) the restrictions and deferral limitations and other conditions applicable to any Restricted Stock Unit Awards or any other Awards not assumed or substituted for shall lapse, and such Restricted Stock Unit Awards or such other Awards shall become free of all restrictions, limitations or conditions and become fully vested and transferable to the full extent of the original grant, (iv) all Performance Awards assumed or substituted for shall be considered to be earned and payable in full, and any deferral or other restriction shall lapse and such Performance Awards shall be immediately settled or distributed, and (v) all Awards not assumed or substituted for shall terminate immediately after the Change in Control.

(c) The Committee, in its discretion, may determine that, upon the occurrence of a Change in Control of the Company, each Option and Stock Appreciation Right outstanding shall terminate within a specified number of days after notice to the Participant, and/or that each Participant shall receive, with respect to each Share subject to such Option or Stock Appreciation Right, an amount equal to the excess (if any) of the Fair Market Value of such Share immediately prior to the occurrence of such Change in Control over the exercise price per share of such Option and/or Stock Appreciation Right; such amount to be payable in cash, in one or more kinds of stock or property (including the stock or property, if any, payable in the transaction) or in a combination thereof, as the Committee, in its discretion, shall determine.

11.3. Change in Control. For purposes of the Plan, unless otherwise provided in an Award Agreement, Change in Control means the occurrence of any one of the following events:

(i) During any twenty-four (24) month period, individuals who, as of the beginning of such period, constitute the Board (the “Incumbent Directors”) cease for any reason to constitute at least a majority of the Board, provided that any person becoming a director subsequent to the beginning of such period whose election or nomination for election was approved by a vote of at least a majority of the Incumbent Directors then on the Board (either by a specific vote or by approval of the proxy statement of the Company in which such person is named as a nominee for director, without written objection to such nomination) shall be an Incumbent Director; provided , however , that no individual initially elected or nominated as a director of the Company as a result of an actual or threatened election contest with respect to directors or as a result of any other actual or threatened solicitation of proxies by or on behalf of any person other than the Board shall be deemed to be an Incumbent Director;

(ii) Any “person” (as such term is defined in the Exchange Act and as used in Sections 13(d)(3) and 14(d)(2) of the Exchange Act) is or becomes a “beneficial owner” (as defined in Rule 13d-3 under the Exchange Act), directly or indirectly, of securities of the Company representing 50% or more of the combined voting power of the Company’s

then outstanding securities eligible to vote for the election of the Board (the “ Company Voting Securities”); provided , however , that the event described in this paragraph (ii) shall not be deemed to be a Change in Control by virtue of any of the following acquisitions: (A) by the Company or any subsidiary, (B) by any employee benefit plan (or related trust) sponsored or maintained by the Company or any subsidiary, (C) by any underwriter temporarily holding securities pursuant to an offering of such securities, (D) pursuant to a Non-Qualifying Transaction, as defined in paragraph (iii), or (E) by any person of Voting Securities from the Company, if a majority of the Incumbent Board approves in advance the acquisition of beneficial ownership of 50% or more of Company Voting Securities by such person;

(iii) The consummation of a merger, consolidation, statutory share exchange or similar form of corporate transaction involving the Company or any of its subsidiaries that requires the approval of the Company’s stockholders, whether for such transaction or the issuance of securities in the transaction (a “Business Combination”), unless immediately following such Business Combination: (A) more than 60% of the total voting power of (x) the corporation resulting from such Business Combination (the “Surviving Corporation”), or (y) if applicable, the ultimate parent corporation that directly or indirectly has beneficial ownership of 100% of the voting securities eligible to elect directors of the Surviving Corporation (the “Parent Corporation”), is represented by Company Voting Securities that were outstanding immediately prior to such Business Combination (or, if applicable, is represented by shares into which such Company Voting Securities were converted pursuant to such Business Combination), and such voting power among the holders thereof is in substantially the same proportion as the voting power of such Company Voting Securities among the holders thereof immediately prior to the Business Combination, (B) no person (other than any employee benefit plan (or related trust) sponsored or maintained by the Surviving Corporation or the Parent Corporation), is or becomes the beneficial owner, directly or indirectly, of 50% or more of the total voting power of the outstanding voting securities eligible to elect directors of the Parent Corporation (or, if there is no Parent Corporation, the Surviving Corporation) and (C) at least a majority of the members of the board of directors of the Parent Corporation (or, if there is no Parent Corporation, the Surviving Corporation) following the consummation of the Business Combination were Incumbent Directors at the time of the Board’s approval of the execution of the initial agreement providing for such Business Combination (any Business Combination which satisfies all of the criteria specified in (A), (B) and (C) above shall be deemed to be a “Non - Qualifying Transaction”);

(iv) The stockholders of the Company approve a plan of complete liquidation or dissolution of the Company or the consummation of a sale of all or substantially all of the Company’s assets; or

(v) The occurrence of any other event that the Board determines by a duly approved resolution constitutes a Change in Control.

Notwithstanding the foregoing, a Change in Control shall not be deemed to occur solely because any person acquires beneficial ownership of more than 50% of the Company Voting Securities as a result of the acquisition of Company Voting Securities by the Company which reduces the

number of Company Voting Securities outstanding; provided , that if after such acquisition by the Company such person becomes the beneficial owner of additional Company Voting Securities that increases the percentage of outstanding Company Voting Securities beneficially owned by such person, a Change in Control of the Company shall then occur.

12. GENERALLY APPLICABLE PROVISIONS

12.1. Amendment and Termination of the Plan . The Board may, from time to time, alter, amend, suspend or terminate the Plan as it shall deem advisable, subject to any requirement for stockholder approval imposed by applicable law, including the rules and regulations of the NASDAQ Stock Market (or such other principal securities market on which the Shares are traded); provided that the Board may not amend the Plan in any manner that would result in noncompliance with Rule 16b-3 of the Exchange Act; and further provided that the Board may not, without the approval of the Company’s stockholders to the extent required by such applicable law, amend the Plan to (a) increase the number of Shares that may be the subject of Awards under the Plan (except for adjustments pursuant to Section 12.2), (b) expand the types of awards available under the Plan, (c) materially expand the class of persons eligible to participate in the Plan, (d) amend any provision of Section 5.3, or (e) increase the maximum permissible term of any Option specified by Section 5.4 or the maximum permissible term of a Stock Appreciation Right. The Board may not without the approval of the Company’s stockholders take any action with respect to an Option or Stock Appreciation Right that may be treated as a repricing under the rules and regulations of the NASDAQ Stock Market (or such other principal securities market on which the Shares are traded), including a reduction of the exercise price of an Option or Stock Appreciation Right or the exchange of an Option or Stock Appreciation Right for cash or another Award. In addition, no amendments to, or termination of, the Plan shall in any way impair the rights of a Participant under any Award previously granted without such Participant’s consent.

12.2. Adjustments . In the event of any merger, reorganization, consolidation, recapitalization, dividend or distribution (whether in cash, shares or other property, other than a regular cash dividend), stock split, reverse stock split, spin-off or similar transaction or other change in corporate structure affecting the Shares or the value thereof, such adjustments and other substitutions shall be made to the Plan and to Awards as the Committee, in its sole discretion, deems equitable or appropriate taking into consideration the accounting and tax consequences, including such adjustments in the aggregate number, class and kind of securities that may be delivered under the Plan and, in the aggregate or to any one Participant, in the number, class, kind and option or exercise price of securities subject to outstanding Awards granted under the Plan (including, if the Committee deems appropriate, the substitution of similar options to purchase the shares of, or other awards denominated in the shares of, another company) as the Committee may determine to be appropriate in its sole discretion; provided, however, that the number of Shares subject to any Award shall always be a whole number.

12.3. Transferability of Awards . Except as provided below, and except as otherwise authorized by the Committee in an Award Agreement, no Award and no Shares subject to Awards described in Article 8 that have not been issued or as to which any applicable restriction, performance or deferral period has not lapsed, may be sold, assigned, transferred, pledged or otherwise encumbered, other than by will or the laws of descent and distribution, and such

Award may be exercised during the life of the Participant only by the Participant or the Participant’s guardian or legal representative. Notwithstanding the foregoing, to the extent and under such terms and conditions as determined by the Committee, a Participant may assign or transfer an Award (each transferee thereof, a “Permitted Assignee”) to a “family member” as such term is defined in the General Instructions to Form S-8 (whether by gift or a domestic relations order); provided that such Permitted Assignee shall be bound by and subject to all of the terms and conditions of the Plan and the Award Agreement relating to the transferred Award and shall execute an agreement satisfactory to the Company evidencing such obligations; and provided further that such Participant shall remain bound by the terms and conditions of the Plan. The Company shall cooperate with any Permitted Assignee and the Company’s transfer agent in effectuating any transfer permitted under this Section.

12.4. Termination of Employment . The Committee shall determine and set forth in each Award Agreement whether any Awards granted in such Award Agreement will continue to be exercisable, and the terms of such exercise, on and after the date that a Participant ceases to be employed by or to provide services to the Company or any Subsidiary (including as a Director), whether by reason of death, disability, voluntary or involuntary termination of employment or services, or otherwise. The date of termination of a Participant’s employment or services will be determined by the Committee, which determination will be final.

12.5. Deferral ; Dividend Equivalents . The Committee shall be authorized to establish procedures pursuant to which the payment of any Award may be deferred. Subject to the provisions of the Plan and any Award Agreement, the recipient of an Award (including any deferred Award) other than an Option or Stock Appreciation Right may, if so determined by the Committee, be entitled to receive, currently or on a deferred basis, cash, stock or other property dividends, or cash payments in amounts equivalent to cash, stock or other property dividends on Shares (“Dividend Equivalents”) with respect to the number of Shares covered by the Award, as determined by the Committee, in its sole discretion. The Committee may provide that such amounts and Dividend Equivalents (if any) shall be deemed to have been reinvested in additional Shares or otherwise reinvested and may provide that such amounts and Dividend Equivalents are subject to the same vesting or performance conditions as the underlying Award.

13. MISCELLANEOUS

13.1. Tax Withholding . The Company shall have the right to make all payments or distributions pursuant to the Plan to a Participant (or a Permitted Assignee thereof) (any such person, a “Payee”) net of any applicable federal, state and local taxes required to be paid or withheld as a result of (a) the grant of any Award, (b) the exercise of an Option or Stock Appreciation Right, (c) the delivery of Shares or cash, (d) the lapse of any restrictions in connection with any Award or (e) any other event occurring pursuant to the Plan. The Company or any Subsidiary shall have the right to withhold from wages or other amounts otherwise payable to such Payee such withholding taxes as may be required by law, or to otherwise require the Payee to pay such withholding taxes. If the Payee shall fail to make such tax payments as are required, the Company or its Subsidiaries shall, to the extent permitted by law, have the right to deduct any such taxes from any payment of any kind otherwise due to such Payee or to take such other action as may be necessary to satisfy such withholding obligations. The Committee shall be authorized to establish procedures for election by Participants to satisfy such obligation for

the payment of such taxes by tendering previously acquired Shares (either actually or by attestation, valued at their then Fair Market Value), or by directing the Company to retain Shares (up to the Participant’s minimum required tax withholding rate or such other rate that will not trigger a negative accounting impact) otherwise deliverable in connection with the Award.

13.2. Right of Discharge Reserved; Claims to Awards . Nothing in the Plan nor the grant of an Award hereunder shall confer upon any Employee or Director the right to continue in the employment or service of the Company or any Subsidiary or affect any right that the Company or any Subsidiary may have to terminate the employment or service of (or to demote or to exclude from future Awards under the Plan) any such Employee or Director at any time for any reason. Except as specifically provided by the Committee, the Company shall not be liable for the loss of existing or potential profit from an Award granted in the event of termination of an employment or other relationship. No Employee or Participant shall have any claim to be granted any Award under the Plan, and there is no obligation for uniformity of treatment of Employees or Participants under the Plan.

13.3. Prospective Recipient . The prospective recipient of any Award under the Plan shall not, with respect to such Award, be deemed to have become a Participant, or to have any rights with respect to such Award, until and unless such recipient shall have executed an agreement or other instrument evidencing the Award and delivered a copy thereof to the Company, and otherwise complied with the then applicable terms and conditions.

13.4. Substitute Awards . Notwithstanding any other provision of the Plan, the terms of Substitute Awards may vary from the terms set forth in the Plan to the extent the Committee deems appropriate to conform, in whole or in part, to the provisions of the awards in substitution for which they are granted.

13.5. Cancellation of Award . (a) Notwithstanding anything to the contrary contained herein, an Award Agreement may provide that the Award shall be canceled if the Participant, without the consent of the Company, while employed by, or providing services to, the Company or any Subsidiary or after termination of such employment or services, establishes a relationship with a competitor of the Company or any Subsidiary or engages in activity that is in conflict with or adverse to the interest of the Company or any Subsidiary, as determined by the Committee in its sole discretion. The Committee may provide in an Award Agreement that if within the time period specified in the Agreement the Participant establishes a relationship with a competitor or engages in an activity referred to in the preceding sentence, the Participant will forfeit any gain realized on the vesting or exercise of the Award and must repay such gain to the Company.

(b) In the event the Participant ceases to be employed by, or provide services to, the Company on account of a termination for “cause” (as defined below) by the Company, any Award held by the Participant shall terminate as of the date the Participant ceases to be employed by, or provide services to, the Company. In addition, notwithstanding any other provisions of this Section, if the Committee determines that the Participant has engaged in conduct that constitutes cause at any time while the Participant is employed by, or providing services to, the Company or after the Participant’s termination of employment or services, any Awards held by the Participant shall immediately terminate. In the event a Participant’s employment or services is terminated for cause, in addition to the immediate termination of all Awards, the Participant shall automatically forfeit all shares underlying any exercised portion of

an Option for which the Company has not yet delivered the share certificates, upon refund by the Company of the option price paid by the Participant for such shares.

(c) For purposes of this Section, “cause” shall mean, unless otherwise provided in an Award Agreement or another agreement between the Participant and the Company or a Subsidiary or a plan maintained by the Company or a Subsidiary in which the Participant participates, a determination by the Committee that the Participant has breached his or her employment or service contract with the Company, or has been engaged in disloyalty to the Company, including, without limitation, fraud, embezzlement, theft, commission of a felony or proven dishonesty in the course of his or her employment or service, or has disclosed trade secrets or confidential information of the Company to persons not entitled to receive such information, or has breached any written noncompetition or nonsolicitation agreement between the Participant and the Company or has engaged in such other behavior detrimental to the interests of the Company as the Committee determines

13.6. Stop Transfer Orders . All certificates for Shares delivered under the Plan pursuant to any Award shall be subject to such stop-transfer orders and other restrictions as the Committee may deem advisable under the rules, regulations and other requirements of the Securities and Exchange Commission, any stock exchange upon which the Shares are then listed, and any applicable federal or state securities law, and the Committee may cause a legend or legends to be put on any such certificates to make appropriate reference to such restrictions.

13.7. Nature of Payments . All Awards made pursuant to the Plan are in consideration of services performed or to be performed for the Company or any Subsidiary, division or business unit of the Company. Any income or gain realized pursuant to Awards under the Plan and any Stock Appreciation Rights constitute a special incentive payment to the Participant and shall not be taken into account, to the extent permissible under applicable law, as compensation for purposes of any of the employee benefit plans of the Company or any Subsidiary except as may be determined by the Committee or by the Board or board of directors of the applicable Subsidiary.

13.8. Other Plans . Nothing contained in the Plan shall prevent the Board from adopting other or additional compensation arrangements, subject to stockholder approval if such approval is required; and such arrangements may be either generally applicable or applicable only in specific cases.

13.9. Severability . If any provision of the Plan shall be held unlawful or otherwise invalid or unenforceable in whole or in part by a court of competent jurisdiction, such provision shall (a) be deemed limited to the extent that such court of competent jurisdiction deems it lawful, valid and/or enforceable and as so limited shall remain in full force and effect, and (b) not affect any other provision of the Plan or part thereof, each of which shall remain in full force and effect. If the making of any payment or the provision of any other benefit required under the Plan shall be held unlawful or otherwise invalid or unenforceable by a court of competent jurisdiction, such unlawfulness, invalidity or unenforceability shall not prevent any other payment or benefit from being made or provided under the Plan, and if the making of any payment in full or the provision of any other benefit required under the Plan in full would be unlawful or otherwise invalid or unenforceable, then such unlawfulness, invalidity or unenforceability shall not prevent such payment or benefit from being made or provided in part,

to the extent that it would not be unlawful, invalid or unenforceable, and the maximum payment or benefit that would not be unlawful, invalid or unenforceable shall be made or provided under the Plan.

13.10. Construction . As used in the Plan, the words “ include ” and “ including ,” and variations thereof, shall not be deemed to be terms of limitation, but rather shall be deemed to be followed by the words “ without limitation .”

13.11. Unfunded Status of the Plan. The Plan is intended to constitute an “unfunded” plan for incentive and deferred compensation. With respect to any payments not yet made to a Participant by the Company, nothing contained herein shall give any such Participant any rights that are greater than those of a general creditor of the Company. In its sole discretion, the Committee may authorize the creation of trusts or other arrangements to meet the obligations created under the Plan to deliver the Shares or payments in lieu of or with respect to Awards hereunder; provided, however, that the existence of such trusts or other arrangements is consistent with the unfunded status of the Plan.

13.12. Governing Law . The Plan and all determinations made and actions taken thereunder, to the extent not otherwise governed by the Code or the laws of the United States, shall be governed by the laws of the State of Delaware, without reference to principles of conflict of laws, and construed accordingly.

13.13. Effective Date of Plan; Termination of Plan . The Plan shall be effective on the date of the approval of the Plan by the holders of the shares entitled to vote at a duly constituted meeting of the stockholders of the Company. The Plan shall be null and void and of no effect if the foregoing condition is not fulfilled and in such event each Award shall, notwithstanding any of the preceding provisions of the Plan, be null and void and of no effect. Awards may be granted under the Plan at any time and from time to time on or prior to the tenth anniversary of the effective date of the Plan, on which date the Plan will expire except as to Awards then outstanding under the Plan. Such outstanding Awards shall remain in effect until they have been exercised or terminated, or have expired.

13.14. Foreign Employees . Awards may be granted to Participants who are foreign nationals or employed outside the United States, or both, on such terms and conditions different from those applicable to Awards to Employees employed in the United States as may, in the judgment of the Committee, be necessary or desirable in order to recognize differences in local law or tax policy. The Committee also may impose conditions on the exercise or vesting of Awards in order to minimize the Company’s obligation with respect to tax equalization for Employees on assignments outside their home country.

13.15. Compliance with Section 409A of the Code. This Plan is intended to comply and shall be administered in a manner that is intended to comply with Section 409A of the Code and shall be construed and interpreted in accordance with such intent. To the extent that an Award or the payment, settlement or deferral thereof is subject to Section 409A of the Code, the Award shall be granted, paid, settled or deferred in a manner that will comply with Section 409A of the Code, including regulations or other guidance issued with respect thereto, except as otherwise determined by the Committee. Any provision of this Plan that would cause the grant of an Award or the payment, settlement or deferral thereof to fail to satisfy Section 409A of the Code

shall be amended to comply with Section 409A of the Code on a timely basis, which may be made on a retroactive basis, in accordance with regulations and other guidance issued under Section 409A of the Code.

13.16. Captions . The captions in the Plan are for convenience of reference only, and are not intended to narrow, limit or affect the substance or interpretation of the provisions contained herein.

DELAWARE	000-31161	23-2908305
(State or other jurisdiction	(Commission File Number)	(I.R.S. Employer
of incorporation)		Identification No.)

Date: April 12, 2007	Arena Pharmaceuticals, Inc.


	By:	/s/ Steven W. Spector
		Steven W. Spector
		SVP, General Counsel and Secretary

Exhibit No.		Description

10.1		Arena 2006 Long-Term Incentive Plan, as Amended.

(d)		Exhibits.

		10.1 Arena 2006 Long-Term Incentive Plan, as Amended.