EXHIBIT 99.1

IMMUNOMEDICS, INC.

2006 STOCK INCENTIVE PLAN

ARTICLE ONE

GENERAL PROVISIONS

This 2006 Stock Incentive Plan is intended to promote the interests of Immunomedics, Inc., a Delaware corporation, by providing eligible persons in the Corporation’s service with the opportunity to acquire a proprietary interest, or otherwise increase their proprietary interest, in the Corporation as an incentive for them to remain in such service.

Capitalized terms shall have the meanings assigned to such terms in the attached Appendix.

A. The Plan shall be divided into three separate equity incentive programs:

- the Discretionary Grant Program under which eligible persons may, at the discretion of the Plan Administrator, be granted options to purchase shares of Common Stock or stock appreciation rights tied to the value of such Common Stock,

- the Stock Issuance Program under which eligible persons may, at the discretion of the Plan Administrator, be issued shares of Common Stock pursuant to restricted stock awards, restricted stock units, performance shares or other stock-based awards which vest upon the completion of a designated service period or the attainment of pre-established performance milestones, or such shares of Common Stock may be issued as a fully-vested bonus for services rendered the Corporation (or any Parent or Subsidiary), and

- the Automatic Grant Program under which eligible non-employee Board members will automatically receive grants at designated intervals over their period of continued Board service.

B. The provisions of Articles One and Five shall apply to all equity programs under the Plan and shall govern the interests of all persons under the Plan.

A. The Compensation Committee shall have sole and exclusive authority to administer the Discretionary Grant and Stock Issuance Programs with respect to Section 16 Insiders. Administration of the Discretionary Grant and Stock Issuance Programs with respect to all other persons eligible to participate in those programs may, at the Board’s discretion, be vested in the Compensation Committee or a Secondary Board Committee, or the Board may retain the power to administer those programs with respect to all such persons. However, any Awards made to the members of the Compensation Committee other than pursuant to the Automatic Grant Program must be authorized by a disinterested majority of the Board.

B. Members of the Compensation Committee or any Secondary Board Committee shall serve for such period of time as the Board may determine and may be removed by the Board at any time. The Board may also at any time terminate the functions of any Secondary Board Committee and reassume all powers and authority previously delegated to such committee.

C. Each Plan Administrator shall, within the scope of its administrative functions under the Plan, have full power and authority (subject to the provisions of the Plan) to establish such rules and regulations as it may deem appropriate for proper administration of the Discretionary Grant and Stock Issuance Programs and to make such determinations under, and issue such interpretations of, the provisions of those programs and any outstanding Awards thereunder as it may deem necessary or advisable. Decisions of the Plan Administrator within the scope of its administrative functions under the Plan shall be final and binding on all parties who have an interest in the Discretionary Grant and Stock Issuance Programs under its jurisdiction or any Award thereunder.

D. Service as a Plan Administrator by the members of the Compensation Committee or the Secondary Board Committee shall constitute service as Board members, and the members of each such committee shall accordingly be entitled to full indemnification and reimbursement as Board members for their service on such committee. No member of the Compensation Committee or the Secondary Board Committee shall be liable for any act or omission made in good faith with respect to the Plan or any Award made thereunder.

E. Administration of the Automatic Grant Program shall be self-executing in accordance with the terms of that program, and no Plan Administrator shall exercise any discretionary functions with respect to any Award made under that program, except that the Compensation Committee shall have the express authority to establish from time to time the specific number of shares to be subject to the initial and annual Awards made to the non-employee Board members under such program.

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A. The persons eligible to participate in the Discretionary Grant and Stock Issuance Programs are as follows:

(i) Employees,

(ii) non-employee members of the Board or the board of directors of any Parent or Subsidiary, and

(iii) consultants and other independent advisors who provide services to the Corporation (or any Parent or Subsidiary).

B. The Plan Administrator shall have full authority to determine, (i) with respect to Awards made under the Discretionary Grant Program, which eligible persons are to receive such Awards, the time or times when those Awards are to be made, the number of shares to be covered by each such Award, the time or times when the Award is to vest and become exercisable, the maximum term for which such Award is to remain outstanding and the status of a granted option as either an Incentive Option or a Non-Statutory Option and (ii) with respect to Awards made under the Stock Issuance Program, which eligible persons are to receive such Awards, the time or times when the Awards are to be made, the number of shares subject to each such Award, the vesting and issuance schedules applicable to the shares subject to such Award, the applicable conversion rates for performance share awards and the cash consideration (if any) payable for shares issuable under the Stock Issuance Program.

C. The Plan Administrator shall have the absolute discretion either to grant options or stock appreciation rights in accordance with the Discretionary Grant Program or to effect stock issuances and other stock-based awards in accordance with the Stock Issuance Program.

D. The individuals who shall be eligible to participate in the Automatic Grant Program shall be limited to (i) those individuals who first become non-employee Board members on or after the Plan Effective Date, whether through appointment by the Board or election by the Corporation’s shareholders, and (ii) those individuals who continue to serve as non-employee Board members on or after the Plan Effective Date. A non-employee Board member who has previously been in the employ of the Corporation (or any Parent or Subsidiary) shall not be eligible to receive an Award under the Automatic Grant Program at the time he or she first becomes a non-employee Board member, but shall be eligible to receive periodic Awards under the Automatic Grant Program while he or she continues to serve as a non-employee Board member.

A. The stock issuable under the Plan shall be shares of authorized but unissued or reacquired Common Stock, including shares repurchased by the Corporation on the

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open market. The number of shares of Common Stock initially reserved for issuance over the term of the Plan shall be limited to Twelve Million (12,000,000) shares. Such share reserve is comprised of (i) the number of shares of Common Stock available for issuance under the Predecessor Plan on the Plan Effective Date, including the shares subject to options outstanding at that time under the Predecessor Plan, and (ii) an additional increase of approximately Five Million Two Hundred Sixty Three Thousand Three Hundred Seventy Five (5,263,375) shares of Common Stock. The Plan shall serve as the successor to the Predecessor Plan, and no further stock option grants or stock issuances shall be made under that Predecessor Plan on or after the Plan Effective Date. All options outstanding under the Predecessor Plan on the Plan Effective Date shall be transferred to this Plan as part of the initial share reserve hereunder and shall continue in full force and effect in accordance with their terms, and no provision of this Plan shall be deemed to affect or otherwise modify the rights or obligations of the holders of those options with respect to their acquisition of shares of Common Stock thereunder. To the extent any options outstanding under the Predecessor Plan on the Plan Effective Date expire or terminate unexercised, the number of shares of Common Stock subject to those expired or terminated options at the time of expiration or termination shall be available for one or more Awards made under this Plan.

B. No one person participating in the Plan may receive Awards for more than Five Hundred Thousand (500,000) shares of Common Stock in the aggregate per calendar year.

C. Shares of Common Stock subject to outstanding Awards made under the Plan (including the options transferred from the Predecessor Plan) shall be available for subsequent issuance under the Plan to the extent (i) those Awards expire or terminate for any reason prior to the issuance of the shares of Common Stock subject to those Awards or (ii) the maximum number of shares subject to such Awards are not otherwise issued. Unvested shares issued under the Plan and subsequently forfeited or repurchased by the Corporation, at a price per share not greater than the original issue price paid per share, pursuant to the Corporation’s repurchase rights under the Plan shall be added back to the number of shares of Common Stock reserved for issuance under the Plan and shall accordingly be available for subsequent reissuance. Should the exercise price of an option under the Plan be paid with shares of Common Stock, then the authorized reserve of Common Stock under the Plan shall be reduced by the gross number of shares for which that option is exercised, and not by the net number of shares issued under the exercised stock option. If shares of Common Stock otherwise issuable under the Plan are withheld by the Corporation in satisfaction of the withholding taxes incurred in connection with the issuance, exercise or vesting of an Award, then the number of shares of Common Stock available for issuance under the Plan shall be reduced by the gross number of shares issued, exercised or vesting under such Award, calculated in each instance prior to any such share withholding.

D. If any change is made to the Common Stock by reason of any stock split, stock dividend, recapitalization, combination of shares, exchange of shares or other change affecting the outstanding Common Stock as a class without the Corporation’s receipt of consideration or if any spin-off of one or more Subsidiaries results in a substantial reduction in

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the Fair Market Value per share of the outstanding Common Stock, appropriate adjustments shall be made by the Plan Administrator to (i) the maximum number and/or class of securities issuable under the Plan, (ii) the maximum number and/or class of securities for which any one person may receive Awards under the Plan per calendar year, (iii) the maximum number and/or class of securities for which stock option grants and restricted stock unit awards may subsequently be made under the Automatic Grant Program to new and continuing non-employee Board members, (iv) the number and/or class of securities and the exercise or base price per share in effect under each outstanding Award under the Discretionary Grant Program and (v) the number and/or class of securities subject to each outstanding Award under the Stock Issuance Program, the applicable conversion ratios for any performance shares and the cash consideration (if any) payable per share under each such Award. To the extent the foregoing adjustments are to be made to outstanding Awards, such adjustments shall be effected in a manner which shall preclude the enlargement or dilution of rights and benefits under those Awards. The adjustments determined by the Plan Administrator shall be final, binding and conclusive.

E. Outstanding Awards under the Plan shall in no way affect the right of the Corporation to adjust, reclassify, reorganize or otherwise change its capital or business structure or to merge, consolidate, dissolve, liquidate or sell or transfer all or any part of its business or assets.

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ARTICLE TWO

DISCRETIONARY GRANT PROGRAM

Each option shall be evidenced by one or more documents in the form approved by the Plan Administrator; provided , however, that each such document shall comply with the terms specified below. Each document evidencing an Incentive Option shall, in addition, be subject to the provisions of the Plan applicable to such options.

A. Exercise Price .

1. The exercise price per share shall be fixed by the Plan Administrator; provided, however, that such exercise price shall not be less than one hundred percent (100%) of the Fair Market Value per share of Common Stock on the grant date.

2. The exercise price shall become immediately due upon exercise of the option and shall, subject to the provisions of the documents evidencing the option, be payable in one or more of the forms specified below:

(i) cash or check made payable to the Corporation,

(ii) shares of Common Stock valued at Fair Market Value on the Exercise Date and held for the requisite period (if any) necessary to avoid any additional charges to the Corporation’s earnings for financial reporting purposes, or

(iii) to the extent the option is exercised for vested shares, through a special sale and remittance procedure pursuant to which the Optionee shall concurrently provide instructions to (a) a brokerage firm (reasonably satisfactory to the Corporation for purposes of administering such procedure in compliance with the Corporation’s pre-clearance/pre-notification policies) to effect the immediate sale of the purchased shares and remit to the Corporation, out of the sale proceeds available on the settlement date, sufficient funds to cover the aggregate exercise price payable for the purchased shares plus all applicable income and employment taxes required to be withheld by the Corporation by reason of such exercise and (b) the Corporation to deliver the certificates for the purchased shares directly to such brokerage firm on such settlement date in order to complete the sale.

Except to the extent such sale and remittance procedure is utilized, payment of the exercise price for the purchased shares must be made on the Exercise Date.

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B. Exercise and Term of Options . Each option shall be exercisable at such time or times, during such period and for such number of shares as shall be determined by the Plan Administrator and set forth in the documents evidencing the option. However, no option shall have a term in excess of seven (7) years measured from the grant date.

C. Effect of Termination of Service .

1. The following provisions shall govern the exercise of any options granted pursuant to the Discretionary Grant Program that are outstanding at the time of the Optionee’s cessation of Service or death:

(i) Any option outstanding at the time of the Optionee’s cessation of Service for any reason shall remain exercisable for such period of time thereafter as shall be determined by the Plan Administrator and set forth in the documents evidencing the option, but no such option shall be exercisable after the expiration of the option term.

(ii) Any option held by the Optionee at the time of the Optionee’s death and exercisable in whole or in part at that time may be subsequently exercised by the personal representative of the Optionee’s estate or by the person or persons to whom the option is transferred pursuant to the Optionee’s will or the laws of inheritance or by the Optionee’s designated beneficiary or beneficiaries of that option.

(iii) Should the Optionee’s Service be terminated for Misconduct or should the Optionee otherwise engage in Misconduct while holding one or more outstanding options granted under this Article Two, then all of those options shall terminate immediately and cease to be outstanding.

(iv) During the applicable post-Service exercise period, the option may not be exercised for more than the number of vested shares for which the option is at the time exercisable. No additional shares shall vest under the option following the Optionee’s cessation of Service, except to the extent (if any) specifically authorized by the Plan Administrator in its sole discretion pursuant to an express written agreement with the Optionee. Upon the expiration of the applicable exercise period or (if earlier) upon the expiration of the option term, the option shall terminate and cease to be outstanding for any shares for which the option has not been exercised.

2. The Plan Administrator shall have complete discretion, exercisable either at the time an option is granted or at any time while the option remains outstanding, to:

(i) extend the period of time for which the option is to remain exercisable following the Optionee’s cessation of Service from the limited exercise period otherwise in effect for that option to such greater period of time as the Plan Administrator shall deem appropriate, but in no event beyond the expiration of the option term,

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(ii) include an automatic extension provision whereby the specified post-Service exercise period in effect for any option granted under this Article Two shall automatically be extended by an additional period of time equal in duration to any interval within the specified post-Service exercise period during which the exercise of that option or the immediate sale of the shares acquired under such option could not be effected in compliance with applicable federal and state securities laws, but in no event shall such an extension result in the continuation of such option beyond the expiration date of the term of that option, and/or

(iii) permit the option to be exercised, during the applicable post-Service exercise period, not only with respect to the number of vested shares of Common Stock for which such option is exercisable at the time of the Optionee’s cessation of Service but also with respect to one or more additional installments in which the Optionee would have vested had the Optionee continued in Service.

D. Stockholder Rights . The holder of an option shall have no stockholder rights with respect to the shares subject to the option until such person shall have exercised the option, paid the exercise price and become a holder of record of the purchased shares.

E. Repurchase Rights . The Plan Administrator shall have the discretion to grant options which are exercisable for unvested shares of Common Stock. Should the Optionee cease Service while such shares are unvested, the Corporation shall have the right to repurchase any or all of those unvested shares at a price per share equal to the lower of (i) the exercise price paid per share or (ii) the Fair Market Value per share of Common Stock at the time of repurchase. The terms upon which such repurchase right shall be exercisable (including the period and procedure for exercise and the appropriate vesting schedule for the purchased shares) shall be established by the Plan Administrator and set forth in the document evidencing such repurchase right.

F. Transferability of Options . The transferability of options granted under the Plan shall be governed by the following provisions:

(i) Incentive Options : During the lifetime of the Optionee, Incentive Options shall be exercisable only by the Optionee and shall not be assignable or transferable other than by will or the laws of inheritance following the Optionee’s death.

(ii) Non-Statutory Options . Non-Statutory Options shall be subject to the same limitation on transfer as Incentive Options, except that the Plan Administrator may structure one or more Non-Statutory Options so that the option may be assigned in whole or in part during the Optionee’s lifetime to one or more Family Members of the Optionee or to a trust

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established exclusively for the Optionee and/or one or more such Family Members, to the extent such assignment is in connection with the Optionee’s estate plan or pursuant to a domestic relations order. The assigned portion may only be exercised by the person or persons who acquire a proprietary interest in the option pursuant to the assignment. The terms applicable to the assigned portion shall be the same as those in effect for the option immediately prior to such assignment and shall be set forth in such documents issued to the assignee as the Plan Administrator may deem appropriate.

(iii) Beneficiary Designations . Notwithstanding the foregoing, the Optionee may designate one or more persons as the beneficiary or beneficiaries of his or her outstanding options under this Article Two (whether Incentive Options or Non-Statutory Options), and those options shall, in accordance with such designation, automatically be transferred to such beneficiary or beneficiaries upon the Optionee’s death while holding those options. Such beneficiary or beneficiaries shall take the transferred options subject to all the terms and conditions of the applicable agreement evidencing each such transferred option, including (without limitation) the limited time period during which the option may be exercised following the Optionee’s death.

The terms specified below shall be applicable to all Incentive Options. Except as modified by the provisions of this Section II, all the provisions of Articles One, Two and Five shall be applicable to Incentive Options. Options which are specifically designated as Non-Statutory Options when issued under the Plan shall not be subject to the terms of this Section II.

A. Eligibility . Incentive Options may only be granted to Employees.

B. Dollar Limitation . The aggregate Fair Market Value of the shares of Common Stock (determined as of the respective date or dates of grant) for which one or more options granted to any Employee under the Plan (or any other option plan of the Corporation or any Parent or Subsidiary) may for the first time become exercisable as Incentive Options during any one calendar year shall not exceed the sum of One Hundred Thousand Dollars ($100,000).

To the extent the Employee holds two (2) or more such options which become exercisable for the first time in the same calendar year, then for purposes of the foregoing limitations on the exercisability of those options as Incentive Options, such options shall be deemed to become first exercisable in that calendar year on the basis of the chronological order in which they were granted, except to the extent otherwise provided under applicable law or regulation.

C. 10% Stockholder . If any Employee to whom an Incentive Option is granted is a 10% Stockholder, then the exercise price per share shall not be less than one hundred ten percent (110%) of the Fair Market Value per share of Common Stock on the option grant date, and the option term shall not exceed five (5) years measured from the option grant date.

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A. Authority . The Plan Administrator shall have full power and authority, exercisable in its sole discretion, to grant stock appreciation rights in accordance with this Section III to selected Optionees or other individuals eligible to receive option grants under the Discretionary Grant Program.

B. Types . Two types of stock appreciation rights shall be authorized for issuance under this Section III: (i) tandem stock appreciation rights (“Tandem Rights”) and (ii) stand-alone stock appreciation rights (“Stand-alone Rights”).

C. Tandem Rights . The following terms and conditions shall govern the grant and exercise of Tandem Rights.

1. One or more Optionees may be granted a Tandem Right, exercisable upon such terms and conditions as the Plan Administrator may establish, to elect between the exercise of the underlying option for shares of Common Stock or the surrender of that option in exchange for a distribution from the Corporation in an amount equal to the excess of (i) the Fair Market Value (on the option surrender date) of the number of shares in which the Optionee is at the time vested under the surrendered option (or surrendered portion thereof) over (ii) the aggregate exercise price payable for such vested shares.

2. No such option surrender shall be effective unless it is approved by the Plan Administrator, either at the time of the actual option surrender or at any earlier time. If the surrender is so approved, then the distribution to which the Optionee shall accordingly become entitled under this Section III shall be made in shares of Common Stock valued at Fair Market Value on the option surrender date.

3. If the surrender of an option is not approved by the Plan Administrator, then the Optionee shall retain whatever rights the Optionee had under the surrendered option (or surrendered portion thereof) on the option surrender date and may exercise such rights at any time prior to the later of (i) five (5) business days after the receipt of the rejection notice or (ii) the last day on which the option is otherwise exercisable in accordance with the terms of the instrument evidencing such option, but in no event may such rights be exercised after the specified expiration date of the option term.

D. Stand-Alone Rights . The following terms and conditions shall govern the grant and exercise of Stand-alone Rights:

1. One or more individuals eligible to participate in the Discretionary Grant Program may be granted a Stand-alone Right not tied to any underlying option under this Discretionary Grant Program. The Stand-alone Right shall relate to a specified number of shares of Common Stock and shall be exercisable upon such terms and conditions as the Plan Administrator may establish. In no event, however, may the Stand-alone Right have a maximum term in excess of seven (7) years measured from the grant date. Upon exercise of the Stand-

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alone Right, the holder shall be entitled to receive a distribution from the Corporation in an amount equal to the excess of (i) the aggregate Fair Market Value (on the exercise date) of the shares of Common Stock underlying the exercised right over (ii) the aggregate base price in effect for those shares.

2. The number of shares of Common Stock underlying each Stand-alone Right and the base price in effect for those shares shall be determined by the Plan Administrator in its sole discretion at the time the Stand-alone Right is granted. In no event, however, may the base price per share be less than the Fair Market Value per underlying share of Common Stock on the grant date. In the event outstanding Stand-alone Rights are to be assumed in connection with a Change in Control transaction or otherwise continued in effect, the shares of Common Stock underlying each such Stand-alone Right shall be adjusted immediately after such Change in Control so as to apply to the number and class of securities into which those shares of Common Stock would have been converted in consummation of such Change in Control had those shares actually been outstanding at that time. Appropriate adjustments to reflect such Change in Control shall also be made to the base price per share in effect under each outstanding Stand-alone Right, provided the aggregate base price shall remain the same. To the extent the actual holders of the Corporation’s outstanding Common Stock receive cash consideration for their Common Stock in consummation of the Change in Control, the successor corporation may, in connection with the assumption or continuation of the outstanding Stand-alone Rights under the Discretionary Grant Program, substitute, for the securities underlying those assumed rights, one or more shares of its own common stock with a fair market value equivalent to the cash consideration paid per share of Common Stock in the Change in Control transaction, provided such common stock is readily tradable on an established U.S. securities exchange or market.

3. Stand-alone Rights shall be subject to the same transferability restrictions applicable to Non-Statutory Options and may not be transferred during the holder’s lifetime, except if such assignment is in connection with the holder’s estate plan and is to one or more Family Members of the holder or to a trust established for the holder and/or one or more such Family Members or pursuant to a domestic relations order covering the Stand-alone Right as marital property. In addition, one or more beneficiaries may be designated for an outstanding Stand-alone Right in accordance with substantially the same terms and provisions as set forth in Section I.F of this Article Two.

4. The distribution with respect to an exercised Stand-alone Right shall be made in shares of Common Stock valued at Fair Market Value on the exercise date.

5. The holder of a Stand-alone Right shall have no shareholder rights with respect to the shares subject to the Stand-alone Right unless and until such person shall have exercised the Stand-alone Right and become a holder of record of the shares of Common Stock issued upon the exercise of such Stand-alone Right.

E. Post-Service Exercise . The provisions governing the exercise of Tandem and Stand-alone Rights following the cessation of the recipient’s Service shall be substantially the same as those set forth in Section I.C of this Article Two for the options granted under the

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Discretionary Grant Program, and the Plan Administrator’s discretionary authority under Section I.C.2 of this Article Two shall also extend to any outstanding Tandem or Stand-alone Appreciation Rights.

F. Gross Counting . Upon the exercise of any Tandem or Stand-alone Right under this Section III, the share reserve under Section V of Article One shall be reduced by the gross number of shares as to which such right is exercised, and not by the net number of shares actually issued by the Corporation upon such exercise.

A. In the event of a Change in Control, each outstanding Award under the Discretionary Grant Program shall automatically accelerate so that each such Award shall, immediately prior to the effective date of that Change in Control, become exercisable as to all the shares of Common Stock at the time subject to such Award and may be exercised as to any or all of those shares as fully vested shares of Common Stock. However, an outstanding Award under the Discretionary Grant Program shall not become exercisable on such an accelerated basis if and to the extent: (i) such Award is to be assumed by the successor corporation (or parent thereof) or is otherwise to continue in full force and effect pursuant to the terms of the Change in Control transaction or (ii) such Award is to be replaced with a cash retention program of the successor corporation which preserves the spread existing at the time of the Change in Control on any shares as to which the Award is not otherwise at that time vested and exercisable and provides for subsequent payout of that spread in accordance with the same exercise/vesting schedule in effect for that Award or (iii) the acceleration of such Award is subject to other limitations imposed by the Plan Administrator.

B. All outstanding repurchase rights under the Discretionary Grant Program shall automatically terminate, and the shares of Common Stock subject to those terminated rights shall immediately vest in full, in the event of a Change in Control, except to the extent: (i) those repurchase rights are to be assigned to the successor corporation (or parent thereof) or are otherwise to continue in full force and effect pursuant to the terms of the Change in Control transaction or (ii) such accelerated vesting is precluded by other limitations imposed by the Plan Administrator.

C. Immediately following the consummation of the Change in Control, all outstanding Awards under the Discretionary Grant Program shall terminate and cease to be outstanding, except to the extent assumed by the successor corporation (or parent thereof) or otherwise continued in full force and effect pursuant to the terms of the Change in Control transaction.

D. Each option which is assumed in connection with a Change in Control or otherwise continued in effect shall be appropriately adjusted, immediately after such Change in Control, to apply to the number and class of securities which would have been issuable to the Optionee in consummation of such Change in Control had the option been exercised immediately prior to such Change in Control. Appropriate adjustments to reflect such Change in

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Control shall also be made to (i) the exercise price payable per share under each outstanding option, provided the aggregate exercise price payable for such securities shall remain the same, (ii) the maximum number and/or class of securities available for issuance over the remaining term of the Plan (iii) the maximum number and/or class of securities which may be issued without cash consideration under the Stock Issuance Program and (iv) the maximum number and/or class of securities for which any one person may receive Awards under the Plan per calendar year. To the extent the actual holders of the Corporation’s outstanding Common Stock receive cash consideration for their Common Stock in consummation of the Change in Control, the successor corporation may, in connection with the assumption or continuation of the outstanding options under the Discretionary Grant Program, substitute one or more shares of its own common stock with a fair market value equivalent to the cash consideration paid per share of Common Stock in such Change in Control transaction, provided such common stock is readily tradable on an established U.S. securities exchange or market.

E. The Plan Administrator shall have the discretionary authority to structure one or more outstanding Awards rights under the Discretionary Grant Program so that those Awards shall, immediately prior to the effective date of a Change in Control, become exercisable as to all the shares of Common Stock at the time subject to those Awards and may be exercised as to any or all of those shares as fully vested shares of Common Stock, whether or not those Awards are to be assumed in the Change in Control transaction or otherwise continued in effect. In addition, the Plan Administrator shall have the discretionary authority to structure one or more of the Corporation’s repurchase rights under the Discretionary Grant Program so that those rights shall immediately terminate upon the consummation of the Change in Control transaction, and the shares subject to those terminated rights shall thereupon vest in full.

F. The Plan Administrator shall have full power and authority to structure one or more outstanding Awards under the Discretionary Grant Program so that those Awards shall become exercisable as to all the shares of Common Stock at the time subject to those Awards in the event the Optionee’s Service is subsequently terminated by reason of an Involuntary Termination within a designated period following the effective date of any Change in Control transaction in which those Awards do not otherwise fully accelerate. In addition, the Plan Administrator may structure one or more of the Corporation’s repurchase rights so that those rights shall immediately terminate with respect to any shares held by the Optionee at the time of such Involuntary Termination, and the shares subject to those terminated repurchase rights shall accordingly vest in full at that time.

G. The Plan Administrator shall have the discretionary authority to structure one or more outstanding Awards under the Discretionary Grant Program so that those Awards shall, immediately prior to the effective date of a Hostile Take-Over, become exercisable as to all the shares of Common Stock at the time subject to those Awards and may be exercised as to any or all of those shares as fully vested shares of Common Stock. In addition, the Plan Administrator shall have the discretionary authority to structure one or more of the Corporation’s repurchase rights under the Discretionary Grant Program so that those rights shall terminate automatically upon the consummation of such Hostile Take-Over, and the shares subject to those

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terminated rights shall thereupon vest in full. Alternatively, the Plan Administrator may condition the automatic acceleration of one or more outstanding Awards under the Discretionary Grant Program and the termination of one or more of the Corporation’s outstanding repurchase rights under such program upon the subsequent termination of the Optionee’s Service by reason of an Involuntary Termination within a designated period following the effective date of such Hostile Take-Over.

H. The portion of any Incentive Option accelerated in connection with a Change in Control or Hostile Take-Over shall remain exercisable as an Incentive Option only to the extent the applicable One Hundred Thousand Dollar ($100,000) limitation is not exceeded. To the extent such dollar limitation is exceeded, the accelerated portion of such option shall be exercisable as a Non-statutory Option under the Federal tax laws.

The Plan Administrator shall not (i) implement any cancellation/regrant program pursuant to which outstanding options or stock appreciation rights under the Plan are cancelled and new options or stock appreciation rights are granted in replacement with a lower exercise price per share, (ii) cancel outstanding options or stock appreciation rights under the Plan with exercise prices per share in excess of the then current Fair Market Value per share of Common Stock for consideration payable in equity securities of the Corporation or (iii) otherwise directly reduce the exercise price in effect for outstanding options or stock appreciation rights under the Plan, without in each such instance obtaining stockholder approval.

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ARTICLE THREE

STOCK ISSUANCE PROGRAM

Shares of Common Stock may be issued under the Stock Issuance Program, either as vested or unvested shares, through direct and immediate issuances without any intervening option grants. Each such stock issuance shall be evidenced by a Stock Issuance Agreement which complies with the terms specified below. Shares of Common Stock may also be issued under the Stock Issuance Program pursuant to:

(i) share right awards or restricted stock units which entitle the recipients to receive the shares underlying those awards or units upon the attainment of designated performance goals or the satisfaction of specified Service requirements or upon the expiration of a designated time period following the vesting of those awards or units, and

(ii) performance share awards under which the actual number of shares of Common Stock issuable under each such award will vary in relation to the Corporation’s success in attaining one or more pre-established performance goals.

A. Issue Price .

1. The issue price per share shall be fixed by the Plan Administrator, but shall not be less than one hundred percent (100%) of the Fair Market Value per share of Common Stock on the issuance date.

2. Shares of Common Stock may be issued under the Stock Issuance Program for any of the following items of consideration which the Plan Administrator may deem appropriate in each individual instance:

(i) cash or check made payable to the Corporation,

(ii) past services rendered to the Corporation (or any Parent or Subsidiary); or

(iii) any other valid consideration under the Delaware General Corporation Law.

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B. Vesting Provisions .

1. Shares of Common Stock issued under the Stock Issuance Program may, in the discretion of the Plan Administrator, be fully and immediately vested upon issuance or may vest in one or more installments over the Participant’s period of Service or upon the attainment of specified performance objectives. The elements of the vesting schedule applicable to any unvested shares of Common Stock issued under the Stock Issuance Program shall be determined by the Plan Administrator and incorporated into the Stock Issuance Agreement. Shares of Common Stock may also be issued under the Stock Issuance Program pursuant to share right awards or restricted stock units which entitle the recipients to receive the shares underlying those awards or units upon the attainment of designated performance goals or the satisfaction of specified Service requirements or upon the expiration of a designated time period following the vesting of those awards or units, including (without limitation) a deferred distribution date following the termination of the Participant’s Service. Finally, performance shares may be issued under the Stock Issuance Program, with the actual number of shares of Common Stock to be issued pursuant to those performance shares to vary in relation to the level at which one or more pre-established performance goals are attained.

2. The Plan Administrator shall also have the discretionary authority, consistent with Code Section 162(m), to structure one or more Awards under the Stock Issuance Program so that the shares of Common Stock subject to those Awards shall vest (or vest and become issuable) upon the achievement of certain pre-established corporate performance goals based on one or more of the following criteria: (1) return on total stockholder equity; (2) earnings per share of Common Stock; (3) net income or operating income (before or after taxes); (4) earnings before interest, taxes, depreciation and amortization; (5) earnings before interest, taxes, depreciation, amortization and charges for stock-based compensation, (6) sales or revenue targets; (7) return on assets, capital or investment; (8) cash flow; (9) market share; (10) cost reduction goals; (11) budget comparisons; (12) measures of customer satisfaction; (13) any combination of, or a specified increase in, any of the foregoing; (14) new product development or successful completion of research and development projects; and (15) the formation of joint ventures, research or development collaborations, or the completion of other corporate transactions intended to enhance the Corporation’s revenue or profitability or enhance its customer base. In addition, such performance goals may be based upon the attainment of specified levels of the Corporation’s performance under one or more of the measures described above relative to the performance of other entities and may also be based on the performance of any of the Corporation’s business units or divisions or any Parent or Subsidiary. Performance goals may include a minimum threshold level of performance below which no award will be earned, levels of performance at which specified portions of an award will be earned and a maximum level of performance at which an award will be fully earned. The performance goals may, at the time they are established for one or more Awards under the Stock Issuance Program, be subject to adjustment for one or more of the following items: extraordinary, unusual or non-recurring items of gain, loss or expense; items of gain, loss or expense related to (a) the disposal of a business or discontinued operations or (b) the operations of any business acquired by Corporation; accruals for reorganization and restructuring cost and expenses; and items of gain, loss or expense attributable to changes in tax laws and regulations, accounting principles or other applicable laws or regulations.

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3. Any new, substituted or additional securities or other property (including money paid other than as a regular cash dividend) which the Participant may have the right to receive with respect to the Participant’s unvested shares of Common Stock by reason of any stock dividend, stock split, recapitalization, combination of shares, exchange of shares, spin-off transaction or other change affecting the outstanding Common Stock as a class without the Corporation’s receipt of consideration shall be issued subject to (i) the same vesting requirements applicable to the Participant’s unvested shares of Common Stock and (ii) such escrow arrangements as the Plan Administrator shall deem appropriate.

4. The Participant shall have full stockholder rights with respect to any shares of Common Stock issued to the Participant under the Stock Issuance Program, whether or not the Participant’s interest in those shares is vested. Accordingly, the Participant shall have the right to vote such shares and to receive any dividends paid on such shares, subject to any applicable vesting requirements. The Participant shall not have any stockholder rights with respect to the shares of Common Stock subject to a restricted stock unit or other share right award until that award vests and the shares of Common Stock are actually issued thereunder. However, dividend-equivalent units may be paid or credited, either in cash or in actual or phantom shares of Common Stock, on outstanding restricted stock unit or share right awards, subject to such terms and conditions as the Plan Administrator may deem appropriate.

5. Should the Participant cease to remain in Service while holding one or more unvested shares of Common Stock issued under the Stock Issuance Program or should the performance objectives not be attained with respect to one or more such unvested shares of Common Stock, then those shares shall be immediately surrendered to the Corporation for cancellation, and the Participant shall have no further stockholder rights with respect to those shares. To the extent the surrendered shares were previously issued to the Participant for consideration paid in cash or cash equivalent, the Corporation shall repay to the Participant the lower of (i) the cash consideration paid for the surrendered shares or (ii) the Fair Market Value of those shares at the time of cancellation.

6. The Plan Administrator may in its discretion waive the surrender and cancellation of one or more unvested shares of Common Stock which would otherwise occur upon the cessation of the Participant’s Service or the non-attainment of the performance objectives applicable to those shares. Any such waiver shall result in the immediate vesting of the Participant’s interest in the shares of Common Stock as to which the waiver applies. Such waiver may be effected at any time, whether before or after the Participant’s cessation of Service or the attainment or non-attainment of the applicable performance objectives. However, no vesting requirements tied to the attainment of performance objectives may be waived with respect to shares which were intended at the time of issuance to qualify as performance-based compensation under Code Section 162(m), except in the event of the Participant’s Involuntary Termination or as otherwise provided in Section II of this Article Three.

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7. Outstanding share right awards or restricted stock units under the Stock Issuance Program shall automatically terminate, and no shares of Common Stock shall actually be issued in satisfaction of those awards or units, if the performance goals or Service requirements established for such awards or units are not attained or satisfied. The Plan Administrator, however, shall have the discretionary authority to issue vested shares of Common Stock under one or more outstanding share right awards or restricted stock units as to which the designated performance goals or Service requirements have not been attained or satisfied. However, no vesting requirements tied to the attainment of performance goals may be waived with respect to share right awards or restricted stock units which were intended, at the time those awards or units were granted, to qualify as performance-based compensation under Code Section 162(m), except in the event of the Participant’s Involuntary Termination or as otherwise provided in Section II of this Article Three.

A. All of the Corporation’s outstanding repurchase rights under the Stock Issuance Program shall terminate automatically, and all the shares of Common Stock subject to those terminated rights shall immediately vest in full, in the event of any Change in Control, except to the extent (i) those repurchase rights are to be assigned to the successor corporation (or parent thereof) or are otherwise to continue in full force and effect pursuant to the terms of the Change in Control transaction or (ii) such accelerated vesting is precluded by other limitations imposed in the Stock Issuance Agreement.

B. Each outstanding Award under the Stock Issuance Program which is assumed in connection with a Change in Control or otherwise continued in effect shall be adjusted immediately after the consummation of that Change in Control so as to apply to the number and class of securities into which the shares of Common Stock subject to that Award immediately prior to the Change in Control would have been converted in consummation of such Change in Control had those shares actually been outstanding at that time, and appropriate adjustments shall also be made to the cash consideration (if any) payable per share thereunder, provided the aggregate amount of such consideration shall remain the same. To the extent the actual holders of the Corporation’s outstanding Common Stock receive cash consideration for their Common Stock in consummation of the Change in Control, the successor corporation may, in connection with the assumption or continuation of the outstanding Awards, substitute one or more shares of its own common stock with a fair market value equivalent to the cash consideration paid per share of Common Stock in such Change in Control transaction, provided such common stock is readily tradable on an established U.S. securities exchange or market.

C. If an Award under the Stock Issuance Program is not assumed or otherwise continued in effect or replaced with a cash retention program of the successor corporation which preserves the Fair Market Value of the underlying shares of Common Stock at the time of the Change in Control and provides for the subsequent payout of that value in accordance with the same vesting schedule applicable to those shares, then such Award shall vest, and the shares of Common Stock subject to that Award shall be issued as fully-vested shares, immediately prior to the consummation of the Change in Control.

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D. The Plan Administrator shall have the discretionary authority to structure one or more unvested Awards under the Stock Issuance Program so that the shares of Common Stock subject to those Awards shall automatically vest (or vest and become issuable) in whole or in part immediately upon the occurrence of a Change in Control or upon the subsequent termination of the Participant’s Service by reason of an Involuntary Termination within a designated period following the effective date of that Change in Control transaction.

E. The Plan Administrator shall also have the discretionary authority to structure one or more unvested Awards under the Stock Issuance Program so that the shares of Common Stock subject to those Awards shall automatically vest (or vest and become issuable) in whole or in part immediately upon the occurrence of a Hostile Take-Over or upon the subsequent termination of the Participant’s Service by reason of an Involuntary Termination within a designated period following the effective date of that Hostile Take-Over.

F. The Plan Administrator’s authority under Paragraphs D and E of this Section II shall also extend to any Awards under the Stock Issuance Program which are intended to qualify as performance-based compensation under Code Section 162(m), even though the automatic vesting of those issuances, units or awards pursuant to Paragraph D or E of this Section II may result in their loss of performance-based status under Code Section 162(m).

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ARTICLE FOUR

AUTOMATIC GRANT PROGRAM

A. Grant Dates . Grants shall be made pursuant to the Automatic Grant Program in effect under this Article Four as follows:

Initial Grant. Each individual who is first elected or appointed as a non-employee Board member at any time on or after the date of the 2006 Annual Meeting shall automatically be granted, on the date of such initial election or appointment, a Non-Statutory Option to purchase not more than ten thousand (10,000) shares of Common Stock and restricted stock units covering not more than an additional five thousand (5,000) shares of Common Stock, provided that individual has not previously been in the employ of the Corporation or any Parent or Subsidiary. The actual number of shares for which such initial option grant and restricted stock unit award shall be made shall (subject to the respective ten thousand (10,000) and five thousand (5,000)-share limits) be determined by the Plan Administrator at the time of each such grant.

Annual Option Grant . On the date of each annual stockholders meeting, beginning with the 2007 Annual Meeting, each individual who is to continue to serve as a non-employee Board member shall automatically be granted a Non-Statutory Option to purchase not more than ten thousand (10,000) shares of Common Stock, provided such individual has served as a non-employee Board member for a period of at least twelve (12) months. However, any such continuing non-employee Board member who has served in such capacity for at least three (3) months but less than twelve (12) months shall also be entitled to such an automatic annual option grant; provided, however, that the number of shares subject to his or her Non-Statutory Option shall be reduced and pro-rated by multiplying (i) the number of shares that would have otherwise been subject to such option grant had he or she served as a non-employee Board member for at least twelve (12) months as of the date of the annual stockholders meeting on which that option is granted by (ii) a fraction the numerator of which is the number of whole months (rounded to the closest whole month) such individual has in fact served as a non-employee Board member and the denominator of which is twelve (12). The actual number of shares for which such annual option grants are to be made to each continuing non-employee Board member shall (subject to the ten thousand (10,000)-share limit) be determined by the Plan Administrator on or before the date on which those grants are to be made.

Annual Restricted Unit Award . On the date of each annual stockholders meeting, beginning with the 2007 Annual Meeting, each individual who is to continue to serve as a non-employee Board member shall automatically be granted restricted stock units covering not more than an additional five thousand (5,000) shares of Common

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Stock, provided such individual has served as a non-employee Board member for a period of at least three (3) months. The actual number of shares for which such annual restricted stock unit awards are to be made to each continuing non-employee Board member shall (subject to the five thousand (5,000)-share limit) be determined by the Plan Administrator on or before the date on which those awards are to be made. Non-employee Board members who have previously been in the employ of the Corporation (or any Parent or Subsidiary) shall be eligible to receive one or more such annual restricted stock awards over their period of continued Board service.

B. Exercise Price .

1. The exercise price per share for each option granted under this Article Four shall be equal to one hundred percent (100%) of the Fair Market Value per share of Common Stock on the option grant date.

2. The exercise price shall be payable in one or more of the alternative forms authorized under the Discretionary Grant Program. Except to the extent the sale and remittance procedure specified thereunder is utilized, payment of the exercise price for the purchased shares must be made on the Exercise Date.

C. Option Term . Each option granted under this Article Four shall have a maximum term of seven (7) years measured from the option grant date, subject to earlier termination following the Optionee’s cessation of Service.

D. Exercise and Vesting of Options . Each option granted under this Article Four, whether to a new or continuing non-employee Board member, shall be immediately exercisable for any or all of the option shares as fully-vested shares of Common Stock.

E. Vesting of Restricted Stock Units and Issuance of Shares . The initial restricted stock unit award made to a newly appointed or elected non-employee Board member shall vest in full upon such individual’s completion of one (1)-year of service as a non-employee Board member measured from the award date. Each annual restricted stock unit award made to a continuing non-employee Board member shall vest in full upon the earlier of (i) such individual’s completion of one (1)-year of service as a non-employee Board member measured from the award date or (ii) such individual’s continuation in such Board service through the day immediately preceding the next annual stockholders meeting following such award date. However, each restricted stock unit award held by a non-employee Board member under the Automatic Grant Program will immediately vest in full upon his or her cessation of Board service by reason of death or Permanent Disability. Upon the vesting of each restricted stock unit award made under the Automatic Grant Program, the shares of Common Stock underlying those vested units shall be promptly issued.

F. Limited Transferability of Options . Each option under this Article Four may be assigned in whole or in part during the Optionee’s lifetime to one or more of his or her Family Members or to a trust established exclusively for the Optionee and/or one or more such

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Family Members, to the extent such assignment is in connection with the Optionee’s estate plan or pursuant to a domestic relations order. The assigned portion may only be exercised by the person or persons who acquire a proprietary interest in the option pursuant to the assignment. The terms applicable to the assigned portion shall be the same as those in effect for the option immediately prior to such assignment and shall be set forth in such documents issued to the assignee as the Plan Administrator may deem appropriate. The Optionee may also designate one or more persons as the beneficiary or beneficiaries of his or her outstanding options under this Article Four, and the options shall, in accordance with such designation, automatically be transferred to such beneficiary or beneficiaries upon the Optionee’s death while holding those options. Such beneficiary or beneficiaries shall take the transferred options subject to all the terms and conditions of the applicable agreement evidencing each such transferred option, including (without limitation) the limited time period during which the option may be exercised following the Optionee’s death.

G. Termination of Service . The following provisions shall govern the exercise of any options held by the Optionee at the time the Optionee ceases Service:

(i) The Optionee (or, in the event of Optionee’s death while holding the option, the personal representative of the Optionee’s estate or the person or persons to whom the option is transferred pursuant to the Optionee’s will or the laws of inheritance or the designated beneficiary or beneficiaries of such option) shall have a twelve (12)-month period following the date of such cessation of Service in which to exercise such option.

(ii) In no event shall the option remain exercisable after the expiration of the option term. Upon the expiration of the twelve (12)-month exercise period or (if earlier) upon the expiration of the option term, the option shall terminate and cease to be outstanding for any shares for which the option has not been exercised.

A. Should a Change in Control or Hostile Take-Over occur while the individual remains in Service, then the shares of Common Stock which are at that time subject to any outstanding restricted stock units awarded to such individual under the Automatic Grant Program shall, immediately prior to the effective date of such Change in Control or Hostile Take-Over, vest in full and be issued to such individual as soon as administratively practicable thereafter, but in no event later than fifteen (15) business days after the effective date of such Change in Control or Hostile Take-Over.

B. Each option which is assumed in connection with a Change in Control or otherwise continued in effect shall be appropriately adjusted, immediately after such Change in Control, to apply to the number and class of securities which would have been issuable to the Optionee in consummation of such Change in Control had the option been exercised immediately prior to such Change in Control. Appropriate adjustments shall also be made to the

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exercise price payable per share under each outstanding option, provided the aggregate exercise price payable for such securities shall remain the same. To the extent the actual holders of the Corporation’s outstanding Common Stock receive cash consideration for their Common Stock in consummation of the Change in Control, the successor corporation may, in connection with the assumption or continuation of the outstanding options under the Automatic Grant Program, substitute one or more shares of its own common stock with a fair market value equivalent to the cash consideration paid per share of Common Stock in such Change in Control transaction, provided such common stock is readily tradable on an established U.S. securities exchange or market.

The remaining terms of each grant shall be the same as the terms in effect for option grants made under the Discretionary Grant Program, including the prohibition on repricing contained in Section V of Article Two.

The Compensation Committee shall have full power and authority to award, in lieu of one or more initial or annual automatic option grants under this Article Four, shares of Common Stock or restricted stock units which in each instance have an aggregate Fair Market Value substantially equal to the fair value (as determined for financial reporting purposes in accordance with Financial Accounting Standard 123R or any successor standard) of the automatic option grant which such award replaces. Any such alternative award shall be made at the same time the automatic option grant which it replaces would have been made and shall be subject to such vesting provisions (if any) which the Compensation Committee deems appropriate for such replacement award.

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ARTICLE FIVE

MISCELLANEOUS

A. The Corporation’s obligation to deliver shares of Common Stock upon the issuance, exercise or vesting of an Award under the Plan shall be subject to the satisfaction of all applicable income and employment tax withholding requirements.

B. The Plan Administrator may, in its discretion, provide any or all Optionees and Participants to whom Awards are made under the Plan (other than the Awards made under the Automatic Grant Program) with the right to use shares of Common Stock in satisfaction of all or part of the Withholding Taxes to which such individuals may become subject in connection with the issuance, exercise or vesting of those Awards. Such right may be provided to any such holder in either or both of the following formats:

Stock Withholding : The election to have the Corporation withhold, from the shares of Common Stock otherwise issuable upon the issuance, exercise or vesting of such Award, a portion of those shares with an aggregate Fair Market Value equal to the percentage of the Withholding Taxes (not to exceed one hundred percent (100%)) designated by such individual. The shares of Common Stock so withheld shall reduce the number of shares of Common Stock authorized for issuance under the Plan.

Stock Delivery : The election to deliver to the Corporation, at the time of the issuance, exercise or vesting of the Award, one or more shares of Common Stock previously acquired by such holder (other than in connection with the issuance exercise or vesting of the shares triggering the Withholding Taxes) with an aggregate Fair Market Value equal to the percentage of the Withholding Taxes (not to exceed one hundred percent (100%)) designated by the individual. The shares of Common Stock so delivered shall not be added to the shares of Common Stock authorized for issuance under the Plan.

Unvested shares may, in the Plan Administrator’s discretion, be held in escrow by the Corporation until the Participant’s interest in such shares vests or may be issued directly to the Participant with restrictive legends on the certificates evidencing those unvested shares.

A. The Plan shall become effective on the Plan Effective Date.

B. The Plan shall serve as the successor to the Predecessor Plan, and no further option grants or stock issuances shall be made under the Predecessor Plan if this Plan is

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approved by the stockholders at the 2006 Annual Meeting. Such stockholder approval be obtained, then all options outstanding under the Predecessor Plan at the time of the 2006 Annual Meeting shall be transferred to this Plan.

C. The Plan shall terminate upon the earliest to occur of (i) December 6, 2016, (ii) the date on which all shares available for issuance under the Plan shall have been issued as fully vested shares or (iii) the termination of all outstanding Awards in connection with a Change in Control. Should the Plan terminate on December 6, 2016, then all Awards outstanding at that time shall continue to have force and effect in accordance with the provisions of the documents evidencing those Awards.

A. The Board shall have complete and exclusive power and authority to amend or modify the Plan in any or all respects. However, no such amendment or modification shall adversely affect the rights and obligations with respect to Awards at the time outstanding under the Plan unless the Optionee or the Participant consents to such amendment or modification. In addition, amendments to the Plan will be subject to stockholder approval to the extent required under applicable law or regulation or pursuant to the listing standards of the stock exchange (or the Nasdaq National Market) on which the Common Stock is at the time primarily traded.

B. The Compensation Committee of the Board shall have the discretionary authority to adopt and implement from time to time such addenda or subplans to the Plan as it may deem necessary in order to bring the Plan into compliance with applicable laws and regulations of any foreign jurisdictions in which grants or awards are to be made under the Plan and/or to obtain favorable tax treatment in those foreign jurisdictions for the individuals to whom the grants or awards are made.

C. Awards may be made under the Plan that involve shares of Common Stock in excess of the number of shares then available for issuance under the Plan, provided no shares shall actually be issued pursuant to those Awards until the number of shares of Common Stock available for issuance under the Plan is sufficiently increased by stockholder approval of an amendment of the Plan authorizing such increase. If such stockholder approval is not obtained within twelve (12) months after the date the first excess Award is made, then all Awards granted on the basis of such excess shares shall terminate and cease to be outstanding.

Any cash proceeds received by the Corporation from the sale of shares of Common Stock under the Plan shall be used for general corporate purposes.

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A. The implementation of the Plan, the grant of any Award and the issuance of shares of Common Stock in connection with the issuance, exercise or vesting of any Award made under the Plan shall be subject to the Corporation’s procurement of all approvals and permits required by regulatory authorities having jurisdiction over the Plan, the Awards made under the Plan and the shares of Common Stock issuable pursuant to those Awards.

B. No shares of Common Stock or other assets shall be issued or delivered under the Plan unless and until there shall have been compliance with all applicable requirements of applicable securities laws, including the filing and effectiveness of the Form S-8 registration statement for the shares of Common Stock issuable under the Plan, and all applicable listing requirements of any Stock Exchange (or the Nasdaq National Market, if applicable) on which Common Stock is then listed for trading.

Nothing in the Plan shall confer upon the Optionee or the Participant any right to continue in Service for any period of specific duration or interfere with or otherwise restrict in any way the rights of the Corporation (or any Parent or Subsidiary employing or retaining such person) or of the Optionee or the Participant, which rights are hereby expressly reserved by each, to terminate such person’s Service at any time for any reason, with or without cause.

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APPENDIX

The following definitions shall be in effect under the Plan:

A. Annual Meeting shall mean the annual meeting of the Corporation’s shareholders.

B. Automatic Grant Program shall mean the automatic grant program in effect under Article Four of the Plan.

C. Award shall mean any of the following stock or stock-based awards authorized for issuance or grant under the Plan: stock option, stock appreciation right, direct stock issuance, restricted stock or restricted stock unit award, performance share or other stock-based award.

D. Board shall mean the Corporation’s Board of Directors.

E. Change in Control shall mean a change in ownership or control of the Corporation effected through any of the following transactions:

(i) a merger, consolidation or other reorganization approved by the Corporation’s stockholders, unless securities representing more than fifty percent (50%) of the total combined voting power of the voting securities of the successor corporation are immediately thereafter beneficially owned, directly or indirectly and in substantially the same proportion, by the persons who beneficially owned the Corporation’s outstanding voting securities immediately prior to such transaction,

(ii) a stockholder-approved sale, transfer or other disposition (including in whole or in part through one or more licensing arrangements) of all or substantially all of the Corporation’s assets, or

(iii) the closing of any transaction or series of related transactions pursuant to which any person or any group of persons comprising a “group” within the meaning of Rule 13d-5(b)(1) of the 1934 Act (other than the Corporation or a person that, prior to such transaction or series of related transactions, directly or indirectly controls, is controlled by or is under common control with, the Corporation) becomes directly or indirectly the beneficial owner (within the meaning of Rule 13d-3 of the 1934 Act) of securities possessing (or convertible into or exercisable for securities possessing) more than fifty percent (50%) of the total combined voting power of the Corporation’s securities (as measured in terms of the power to vote with respect to the election of Board members) outstanding immediately after the consummation of such transaction or

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series of related transactions, whether such transaction involves a direct issuance from the Corporation or the acquisition of outstanding securities held by one or more of the Corporation’s existing shareholders.

F. Code shall mean the Internal Revenue Code of 1986, as amended.

G. Common Stock shall mean the Corporation’s common stock.

H. Compensation Committee shall mean the Compensation Committee of the Board comprised of two (2) or more non-employee Board members.

I. Corporation shall mean Immunomedics, Inc., a Delaware corporation, and any corporate successor to all or substantially all of the assets or voting stock of Immunomedics, Inc. which has by appropriate action assumed the Plan.

J. Discretionary Grant Program shall mean the discretionary grant program in effect under Article Two of the Plan pursuant to which stock options and stock appreciation rights may be granted to one or more eligible individuals.

K. Eligible Director shall mean a non-employee Board member eligible to participate in the Automatic Grant Program in accordance with the eligibility provisions of Articles One and Four.

L. Employee shall mean an individual who is in the employ of the Corporation (or any Parent or Subsidiary, whether now existing or subsequently established), subject to the control and direction of the employer entity as to both the work to be performed and the manner and method of performance.

M. Exercise Date shall mean the date on which the Corporation shall have received written notice of the option exercise.

N. Fair Market Value per share of Common Stock on any relevant date shall be determined in accordance with the following provisions:

(i) If the Common Stock is at the time traded on the Nasdaq National Market, then the Fair Market Value shall be the closing selling price per share of Common Stock at the close of regular hours trading (i.e., before after- hours trading begins) on the Nasdaq National Market on the date in question, as such price is reported by the National Association of Securities Dealers. If there is no closing selling price for the Common Stock on the date in question, then the Fair Market Value shall be the closing selling price on the last preceding date for which such quotation exists.

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(ii) If the Common Stock is at the time listed on any Stock Exchange, then the Fair Market Value shall be the closing selling price per share of Common Stock at the close of regular hours trading (i.e., before after-hours trading begins) on the date in question on the Stock Exchange determined by the Plan Administrator to be the primary market for the Common Stock, as such price is officially quoted in the composite tape of transactions on such exchange. If there is no closing selling price for the Common Stock on the date in question, then the Fair Market Value shall be the closing selling price on the last preceding date for which such quotation exists.

O. Family Member means, with respect to a particular Optionee or Participant, any child, stepchild, grandchild, parent, stepparent, grandparent, spouse, former spouse, sibling, niece, nephew, mother-in-law, father-in-law, son-in-law, daughter-in-law, brother-in-law or sister-in-law.

P. Hostile Take-Over shall mean a change in ownership or control of the Corporation effected through either of the following transactions:

(i) a change in the composition of the Board over a period of thirty-six (36) consecutive months or less such that a majority of the Board members ceases, by reason of one or more contested elections for Board membership, to be comprised of individuals who either (A) have been Board members continuously since the beginning of such period or (B) have been elected or nominated for election as Board members during such period by at least a majority of the Board members described in clause (A) who were still in office at the time the Board approved such election or nomination, or

(ii) the acquisition, directly or indirectly, by any person or related group of persons (other than the Corporation or a person that directly or indirectly controls, is controlled by, or is under common control with, the Corporation) of beneficial ownership (within the meaning of Rule 13d-3 of the 1934 Act) of securities possessing more than fifty percent (50%) of the total combined voting power of the Corporation’s outstanding securities pursuant to a tender or exchange offer made directly to the Corporation’s shareholders which the Board does not recommend such shareholders to accept.

Q. Incentive Option shall mean an option which satisfies the requirements of Code Section 422.

R. Involuntary Termination shall mean the termination of the Service of any individual which occurs by reason of:

(i) such individual’s involuntary dismissal or discharge by the Corporation (or any Parent or Subsidiary) for reasons other than Misconduct, or

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(ii) such individual’s voluntary resignation following (A) a change in his or her position with the Corporation (or any Parent or Subsidiary) which materially reduces his or her duties and responsibilities or the level of management to which he or she reports, (B) a reduction in his or her level of compensation (including base salary, fringe benefits and target bonus under any corporate-performance based bonus or incentive programs) by more than fifteen percent (15%) or (C) a relocation of such individual’s place of employment by more than fifty (50) miles, provided and only if such change, reduction or relocation is effected by the Corporation (or any Parent or Subsidiary) without the individual’s consent.

S. Misconduct shall mean the commission of any act of fraud, embezzlement or dishonesty by the Optionee or Participant, any unauthorized use or disclosure by such person of confidential information or trade secrets of the Corporation (or any Parent or Subsidiary), or any other intentional misconduct by such person adversely affecting the business or affairs of the Corporation (or any Parent or Subsidiary) in a material manner. The foregoing definition shall not in any way preclude or restrict the right of the Corporation (or any Parent or Subsidiary) to discharge or dismiss any Optionee, Participant or other person in the Service of the Corporation (or any Parent or Subsidiary) for any other acts or omissions, but such other acts or omissions shall not be deemed, for purposes of the Plan, to constitute grounds for termination for Misconduct.

T. 1934 Act shall mean the Securities Exchange Act of 1934, as amended.

U. Non-Statutory Option shall mean an option not intended to satisfy the requirements of Code Section 422.

V. Optionee shall mean any person to whom an option is granted under the Discretionary Grant or Automatic Grant Program.

W. Parent shall mean any corporation (other than the Corporation) in an unbroken chain of corporations ending with the Corporation, provided each corporation in the unbroken chain (other than the Corporation) owns, at the time of the determination, stock possessing fifty percent (50%) or more of the total combined voting power of all classes of stock in one of the other corporations in such chain.

X. Participant shall mean any person who is issued shares of Common Stock, restricted stock units, performance shares or other stock-based awards under the Stock Issuance Program.

Y. Permanent Disability or Permanently Disabled shall mean the inability of the Optionee or the Participant to engage in any substantial gainful activity by reason of any medically determinable physical or mental impairment expected to result in death or to be of continuous duration of twelve (12) months or more. However, solely for purposes of the Automatic Grant Program, Permanent Disability or Permanently Disabled shall mean the

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inability of the non-employee Board member to perform his or her usual duties as a Board member by reason of any medically determinable physical or mental impairment expected to result in death or to be of continuous duration of twelve (12) months or more.

Z. Plan shall mean the Corporation’s 2006 Stock Incentive Plan, as set forth in this document.

AA. Plan Administrator shall mean the particular entity, whether the Compensation Committee, the Board or the Secondary Board Committee, which is authorized to administer the Discretionary Grant and Stock Issuance Programs with respect to one or more classes of eligible persons, to the extent such entity is carrying out its administrative functions under those programs with respect to the persons under its jurisdiction.

BB. Plan Effective Date shall mean the date on which the Plan is approved by the shareholders at the 2006 Annual Meeting.

CC. Predecessor Plan shall mean the Corporation’s 2002 Stock Option Plan as such Plan is in effect immediately prior to the 2006 Annual Meeting.

DD. Secondary Board Committee shall mean a committee of one or more Board members appointed by the Board to administer the Discretionary Grant and Stock Issuance Programs with respect to eligible persons other than Section 16 Insiders.

EE. Section 16 Insider shall mean an officer or director of the Corporation subject to the short-swing profit liabilities of Section 16 of the 1934 Act.

FF. Service shall mean the performance of services for the Corporation (or any Parent or Subsidiary, whether now existing or subsequently established) by a person in the capacity of an Employee, a non-employee member of the board of directors or a consultant or independent advisor, except to the extent otherwise specifically provided in the documents evidencing the option grant or stock issuance. For purposes of the Plan, an Optionee or Participant shall be deemed to cease Service immediately upon the occurrence of the either of the following events: (i) the Optionee or Participant no longer performs services in any of the foregoing capacities for the Corporation or any Parent or Subsidiary or (ii) the entity for which the Optionee or Participant is performing such services ceases to remain a Parent or Subsidiary of the Corporation, even though the Optionee or Participant may subsequently continue to perform services for that entity. Service shall not be deemed to cease during a period of military leave, sick leave or other personal leave approved by the Corporation; provided, however , that should such leave of absence exceed three (3) months, then for purposes of determining the period within which an Incentive Option may be exercised as such under the federal tax laws, the Optionee’s Service shall be deemed to cease on the first day immediately following the expiration of such three (3)-month period, unless Optionee is provided with the right to return to

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Service following such leave either by statute or by written contract. Except to the extent otherwise required by law or expressly authorized by the Plan Administrator or by the Corporation’s written policy on leaves of absence, no Service credit shall be given for vesting purposes for any period the Optionee or Participant is on a leave of absence.

GG. Stock Exchange shall mean either the American Stock Exchange or the New York Stock Exchange.

HH. Stock Issuance Agreement shall mean the agreement entered into by the Corporation and the Participant at the time of issuance of shares of Common Stock under the Stock Issuance Program.

II. Stock Issuance Program shall mean the stock issuance program in effect under Article Three of the Plan.

JJ. Subsidiary shall mean any corporation (other than the Corporation) in an unbroken chain of corporations beginning with the Corporation, provided each corporation (other than the last corporation) in the unbroken chain owns, at the time of the determination, stock possessing fifty percent (50%) or more of the total combined voting power of all classes of stock in one of the other corporations in such chain.

KK. 10% Stockholder shall mean the owner of stock (as determined under Code Section 424(d)) possessing more than ten percent (10%) of the total combined voting power of all classes of stock of the Corporation (or any Parent or Subsidiary).

LL. Withholding Taxes shall mean the applicable income and employment withholding taxes to which to which the Optionee or Participant may become subject in connection with the issuance, exercise or vesting of the Award made to him or her under the Plan.

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AMENDMENT 2007-1

TO THE

IMMUNOMEDICS, INC.

2006 STOCK INCENTIVE PLAN

WHEREAS , Immunomedics, Inc. (the “Corporation”) maintains the Immunomedics, Inc. 2006 Stock Incentive Plan (the “Plan”) for the benefit of its and its affiliates’ eligible employees, non-employee directors, consultants and advisors; and

WHEREAS , pursuant to Article 5, Section IV.A of the Plan, the Board of Directors of the Corporation (the “Board”) may amend the Plan at any time.

NOW, THEREFORE , in accordance with the foregoing, effective May 9, 2007, the Plan shall be amended as follows:

1. The last sentence of Section III.A under Article I is hereby amended in its entirety to read as follows:

“However, any Awards made to the members of the Board or Compensation Committee other than pursuant to the Automatic Grant Program must be authorized and administered by a committee comprised of two (2) or more persons appointed by the Board, all of whom shall be “outside directors” within the meaning of section 162(m) of the Code, “non-employee directors” as defined under Rule 16b-3 promulgated under the 1934 Act, and “independent directors” within the meaning of NASDAQ Rule 4200(15).”

2. The first sentence of Section I.B.6 of Article 3 of the Plan is amended in its entirety to read as follows:

“6. Except as otherwise provided in Section I.C below, the Plan Administrator may in its discretion waive the surrender and cancellation of one or more unvested shares of Common Stock which would otherwise occur upon the cessation of the Participant’s Service or the non-attainment of the performance objectives applicable to those shares.”

3. The second sentence of Section I.B.7 of Article 3 of the Plan is amended in its entirety to read as follows:

“7. Except as otherwise provided in Section I.C below, the Plan Administrator shall have the discretionary authority to issue vested shares of Common Stock under one or more outstanding share right awards or restricted stock units as to which the designated performance goals or Service requirements have not been attained or satisfied.”

4. A new Section I.C is added to Article 3 of the Plan, to read as follows:

“C. Additional Vesting Provisions For Full-Value Awards .

1. Notwithstanding any provision of the Plan to the contrary, a Full-Value Award granted under the Stock Issuance Program shall be subject to a minimum vesting period of one year from the date of grant if such Award is based on the satisfaction of performance

criteria or objectives and a minimum vesting period of three years from the date of grant if such Award is based on the Participant’s satisfaction of specified Service requirements with the Corporation.

2. Notwithstanding any provision of the Plan to the contrary, the Plan Administrator shall not have discretionary authority to waive the vesting period applicable to a Full-Value Award, except in the case of death, Permanent Disability, retirement, Involuntary Termination or a Change in Control.”

7. A new Section O is added to the Appendix to read as follows, and all subsequent sections are re-lettered accordingly:

“O. Full-Value Award shall mean an Award that results in the Corporation transferring the full value of a share of Common Stock in the transaction, whether or not an actual share of stock is issued. Full-Value Awards shall include, but are not limited to, restricted stock awards, restricted stock units, performance shares and other stock-based awards for which the Corporation transfers the full value of a share of Common Stock in the transaction.”

8. In all respects not amended, the Plan is hereby ratified and confirmed.

[SIGNATURE PAGE FOLLOWS ]

IN WITNESS WHEREOF, to record the adoption of this Amendment 2007-1 to the Plan, the Company has caused the execution of this instrument, substantially in the form as set forth herein, on this 31 ^st day of May, 2007.