Amended and Restated 2010 Stock Plan and forms of agreement thereunder

Date of Option Grant:

Number of Option Shares:

Exercise Price per Share:

EX-10.1 4 d741228dex101.htm EX-10.1 EX-10.1

Exhibit 10.1

IGM BIOSCIENCES, INC.

AMENDED AND RESTATED

2010 STOCK PLAN

1. ESTABLISHMENT, PURPOSE AND TERM OF PLAN.

1.1 Establishment. The IGM Biosciences, Inc. 2010 Stock Plan (the “Plan”) has been established effective as of November 1, 2010.

1.2 Purpose. The purpose of the Plan is to advance the interests of the Participating Company Group and its stockholders by providing an incentive to attract, retain and reward persons performing services for the Participating Company Group and by motivating such persons to contribute to the growth and profitability of the Participating Company Group. The Company shall not be liable to any Participant for any tax, interest or penalty the Participant might owe as a result of the grant, holding, vesting, exercise or payment of any Award under the Plan.

1.3 Term of Plan. The Plan shall continue in effect until its termination by the Board; provided, however, that all Awards shall be granted, if at all, within ten (10) years from the earlier of the date the Plan is adopted by the Board or the date the Plan is duly approved by the stockholders of the Company.

2. DEFINITIONS AND CONSTRUCTION.

2.1 Definitions. Whenever used herein, the following terms shall have their respective meanings set forth below:

(a) “Award” means an Option or Stock Purchase Right granted under the Plan.

(b) “Award Agreement” means a written or electronic agreement between the Company and a Participant setting forth the terms, conditions and restrictions of the Award granted to the Participant.

(c) “Board” means the Board of Directors of the Company. If one or more Committees have been appointed by the Board to administer the Plan, “Board” also means such Committee(s).

(d) “Cause” means, unless such term or an equivalent term is otherwise defined with respect to an Award by the Participant’s Award Agreement or written contract of employment or service, any of the following: (i) the Participant’s theft, dishonesty, willful misconduct, breach of fiduciary duty for personal profit, or falsification of any Participating Company documents or records; (ii) the Participant’s material failure to abide by a

Participating Company’s code of conduct or other policies (including, without limitation, policies relating to confidentiality and reasonable workplace conduct); (iii) the Participant’s unauthorized use, misappropriation, destruction or diversion of any tangible or intangible asset or corporate opportunity of a Participating Company (including, without limitation, the Participant’s improper use or disclosure of a Participating Company’s confidential or proprietary information); (iv) any intentional act by the Participant which has a material detrimental effect on a Participating Company’s reputation or business; (v) the Participant’s repeated failure or inability to perform any reasonable assigned duties after written notice from a Participating Company of, and a reasonable opportunity to cure, such failure or inability; (vi) any material breach by the Participant of any employment or service agreement between the Participant and a Participating Company, which breach is not cured pursuant to the terms of such agreement; or (vii) the Participant’s conviction (including any plea of guilty or nolo contendere) of any criminal act involving fraud, dishonesty, misappropriation or moral turpitude, or which impairs the Participant’s ability to perform his or her duties with a Participating Company.

(e) “Change in Control” means, unless such term or an equivalent term is otherwise defined with respect to an Award by the Participant’s Award Agreement or written contract of employment or service, the occurrence of any of the following:

(i) an Ownership Change Event or a series of related Ownership Change Events (collectively, a “Transaction”) in which the stockholders of the Company immediately before the Transaction do not retain immediately after the Transaction, in substantially the same proportions as their ownership of shares of the Company’s voting stock immediately before the Transaction, direct or indirect beneficial ownership of more than fifty percent (50%) of the total combined voting power of the outstanding voting securities of the Company or, in the case of an Ownership Change Event described in Section 2.1(t)(iii), the entity to which the assets of the Company were transferred (the “Transferee”), as the case may be; or

(ii) the liquidation or dissolution of the Company.

For purposes of the preceding sentence, indirect beneficial ownership shall include, without limitation, an interest resulting from ownership of the voting securities of one or more corporations or other business entities which own the Company or the Transferee, as the case may be, either directly or through one or more subsidiary corporations or other business entities. The Board shall have the right to determine whether multiple sales or exchanges of the voting securities of the Company or multiple Ownership Change Events are related, and its determination shall be final, binding and conclusive.

(f) “Code” means the Internal Revenue Code of 1986, as amended, and any applicable regulations promulgated thereunder.

(g) “Committee” means the compensation committee or other committee of the Board duly appointed to administer the Plan and having such powers as shall be specified by the Board. Unless the powers of the Committee have been specifically limited, the Committee shall have all of the powers of the Board granted herein, including, without limitation, the power to amend or terminate the Plan at any time, subject to the terms of the Plan and any applicable limitations imposed by law.

(h) “Company” means IGM Biosciences, Inc., a Delaware corporation, or any successor corporation thereto.

(i) “Consultant” means a person engaged to provide consulting or advisory services (other than as an Employee or a Director) to a Participating Company, provided that the identity of such person, the nature of such services or the entity to which such services are provided would not preclude the Company from offering or selling securities to such person pursuant to the Plan in reliance on either the exemption from registration provided by Rule 701 under the Securities Act or, if the Company is required to file reports pursuant to Section 13 or 15(d) of the Exchange Act, registration on a Form S-8 Registration Statement under the Securities Act.

(j) “Director” means a member of the Board or of the board of directors of any other Participating Company.

(k) “Disability” means the inability of the Participant, in the opinion of a qualified physician acceptable to the Company, to perform the major duties of the Participant’s position with the Participating Company Group because of the sickness or injury of the Participant.

(l) “Employee” means any person treated as an employee (including an Officer or a Director who is also treated as an employee) in the records of a Participating Company and, with respect to any Incentive Stock Option granted to such person, who is an employee for purposes of Section 422 of the Code; provided, however, that neither service as a Director nor payment of a director’s fee shall be sufficient to constitute employment for purposes of the Plan. The Company shall determine in good faith and in the exercise of its discretion whether an individual has become or has ceased to be an Employee and the effective date of such individual’s employment or termination of employment, as the case may be. For purposes of an individual’s rights, if any, under the terms of the Plan as of the time of the Company’s determination of whether or not the individual is an Employee, all such determinations by the Company shall be final, binding and conclusive as to such rights, if any, notwithstanding that the Company or any court of law or governmental agency subsequently makes a contrary determination as to such individual’s status as an Employee.

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

(n) “Fair Market Value” means, as of any date, the value of a share of Stock or other property as determined by the Board, in its discretion, or by the Company, in its discretion, if such determination is expressly allocated to the Company herein, subject to the following:

(i) If, on such date, the Stock is listed on a national or regional securities exchange or market system, the Fair Market Value of a share of Stock shall be the closing price of a share of Stock (or the mean of the closing bid and asked prices of a share of Stock if the Stock is so quoted instead) as quoted on the Nasdaq National Market, The Nasdaq SmallCap Market or such other national or regional securities exchange or market system constituting the primary market for the Stock, as reported in The Wall Street Journal or such other source as the Company deems reliable. If the relevant date does not fall on a day on which the Stock has traded on such securities exchange or market system, the date on which the Fair Market Value shall be established shall be the last day on which the Stock was so traded prior to the relevant date, or such other appropriate day as shall be determined by the Board, in its discretion.

(ii) If, on such date, the Stock is not listed on a national or regional securities exchange or market system, the Fair Market Value of a share of Stock shall be as determined by the Board as follows: (i) for Incentive Stock Options, in good faith and in accordance with Section 1.422-2(e) of the Treasury Regulations; and (ii) for Nonstatutory Stock Options and Stock Purchase Rights, according to a reasonable application of a reasonable valuation method, within the meaning of Section 1.409A-1(b)(5)(iv)(B) of the Treasury Regulations.

(o) “Incentive Stock Option” means an Option intended to be (as set forth in the Award Agreement) and which qualifies as an incentive stock option within the meaning of Section 422(b) of the Code.

(p) “Insider” means an Officer, a Director of the Company or other person whose transactions in Stock are subject to Section 16 of the Exchange Act.

(q) “Nonstatutory Stock Option” means an Option not intended to be (as set forth in the Award Agreement) or which does not qualify as an Incentive Stock Option.

(r) “Officer” means any person designated by the Board as an officer of the Company.

(s) “Option” means a right granted under Section 6 to purchase Stock pursuant to the terms and conditions of the Plan. An Option may be either an Incentive Stock Option or a Nonstatutory Stock Option.

(t) “Ownership Change Event” means the occurrence of any of the following with respect to the Company: (i) the direct or indirect sale or exchange in a single or series of related transactions by the stockholders of the Company of more than fifty percent (50%) of the voting stock of the Company; (ii) a merger or consolidation in which the Company is a party; or (iii) the sale, exchange, or transfer of all or substantially all of the assets of the Company.

(u) “Parent Corporation” means any present or future “parent corporation” of the Company, as defined in Section 424(e) of the Code.

(v) “Participant” means any eligible person who has been granted one or more Awards.

(w) “Participating Company” means the Company or any Parent Corporation or Subsidiary Corporation.

(x) “Participating Company Group” means, at any point in time, all entities collectively which are then Participating Companies.

(y) “Rule 16b-3” means Rule 16b-3 under the Exchange Act, as amended from time to time, or any successor rule or regulation.

(z) “Securities Act” means the Securities Act of 1933, as amended.

(aa) “Service” means a Participant’s employment or service with the Participating Company Group, whether in the capacity of an Employee, a Director or a Consultant. A Participant’s Service shall not be deemed to have terminated merely because of a change in the capacity in which the Participant renders Service to the Participating Company Group or a change in the Participating Company for which the Participant renders such Service, provided that there is no interruption or termination of the Participant’s Service. Furthermore, a Participant’s Service shall not be deemed to have terminated if the Participant takes any military leave, sick leave, or other bona fide leave of absence approved by the Company. However, if any such leave taken by a Participant exceeds ninety (90) days, then on the ninety-first (91st) day following the commencement of such leave the Participant’s Service shall be deemed to have terminated, unless the Participant’s right to return to Service is guaranteed by statute or contract. Notwithstanding the foregoing, unless otherwise designated by the Company or required by law, a leave of absence shall not be treated as Service for purposes of determining vesting under the Participant’s Award Agreement. Except as otherwise provided by the Board, in its discretion, the Participant’s Service shall be deemed to have terminated either upon an actual termination of Service or upon the corporation for which the Participant performs Service ceasing to be a Participating Company. Subject to the foregoing, the Company, in its discretion, shall determine whether the Participant’s Service has terminated and the effective date of and reason for such termination.

(bb) “Stock” means the common stock of the Company, as adjusted from time to time in accordance with Section 4.2.

(cc) “Stock Purchase Right” means a right granted under Section 7 to purchase Stock pursuant to the terms and conditions of the Plan.

(dd) “Subsidiary Corporation” means any present or future “subsidiary corporation” of the Company, as defined in Section 424(f) of the Code.

(ee) “Ten Percent Stockholder” means a person who, at the time an Award is granted to such person, owns stock possessing more than ten percent (10%) of the total combined voting power (as defined in Section 194.5 of the California Corporations Code) of all classes of stock of a Participating Company within the meaning of Section 422(b)(6) of the Code.

(ff) “Treasury Regulations” means regulations issued by the United States Treasury Department.

2.2 Construction. Captions and titles contained herein are for convenience only and shall not affect the meaning or interpretation of any provision of the Plan. Except when otherwise indicated by the context, the singular shall include the plural and the plural shall include the singular. Use of the term “or” is not intended to be exclusive, unless the context clearly requires otherwise.

3. ADMINISTRATION.

3.1 Administration by the Board. The Plan shall be administered by the Board. All questions of interpretation of the Plan or of any Award shall be determined by the Board, and such determinations shall be final and binding upon all persons having an interest in the Plan or such Award.

3.2 Authority of Officers. Any Officer shall have the authority to act on behalf of the Company with respect to any matter, right, obligation, determination or election which is the responsibility of or which is allocated to the Company herein, provided the Officer has apparent authority with respect to such matter, right, obligation, determination or election.

3.3 Powers of the Board. In addition to any other powers set forth in the Plan and subject to the provisions of the Plan, the Board shall have the full and final power and authority, in its discretion:

(a) to determine the persons to whom, and the time or times at which, Awards shall be granted and the number of shares of Stock to be subject to each Award;

(b) to designate Options as Incentive Stock Options or Nonstatutory Stock Options;

(d) to determine the terms, conditions and restrictions applicable to each Award (which need not be identical) and any shares acquired upon the exercise thereof, including, without limitation, (i) the exercise price of the Award, (ii) the method of payment for shares purchased upon the exercise of the Award, (iii) the method for satisfaction of any tax withholding obligation arising in connection with the Award or such shares, including by the

withholding or delivery of shares of stock, (iv) the timing, terms and conditions of the exercisability of the Award or the vesting of any shares acquired upon the exercise thereof, (v) the time of the expiration of the Award, (vi) the effect of the Participant’s termination of Service on any of the foregoing, and (vii) all other terms, conditions and restrictions applicable to the Award or such shares not inconsistent with the terms of the Plan;

(e) to approve one or more forms of Award Agreement;

(f) to amend, modify, extend, cancel or renew any Award or to waive any restrictions or conditions applicable to any Award or any shares acquired upon the exercise thereof;

(g) to accelerate, continue, extend or defer the exercisability of any Award or the vesting of any shares acquired upon the exercise thereof, including with respect to the period following a Participant’s termination of Service;

(h) to prescribe, amend or rescind rules, guidelines and policies relating to the Plan, or to adopt supplements to, or alternative versions of, the Plan, including, without limitation, as the Board deems necessary or desirable to comply with the laws of, or to accommodate the tax policy or custom of, foreign jurisdictions whose citizens may be granted Awards; and

(i) to correct any defect, supply any omission or reconcile any inconsistency in the Plan or any Award Agreement and to make all other determinations and take such other actions with respect to the Plan or any Award as the Board may deem advisable to the extent not inconsistent with the provisions of the Plan or applicable law.

3.4 Administration with Respect to Insiders. With respect to participation by Insiders in the Plan, at any time that any class of equity security of the Company is registered pursuant to Section 12 of the Exchange Act, the Plan shall be administered in compliance with the requirements, if any, of Rule 16b-3.

3.5 Indemnification. In addition to such other rights of indemnification as they may have as members of the Board or officers or employees of the Participating Company Group, members of the Board and any officers or employees of the Participating Company Group to whom authority to act for the Board or the Company is delegated shall be indemnified by the Company against all reasonable expenses, including attorneys’ fees, actually and necessarily incurred in connection with the defense of any action, suit or proceeding, or in connection with any appeal therein, to which they or any of them may be a party by reason of any action taken or failure to act under or in connection with the Plan, or any right granted hereunder, and against all amounts paid by them in settlement thereof (provided such settlement is approved by independent legal counsel selected by the Company) or paid by them in satisfaction of a judgment in any such action, suit or proceeding, except in relation to matters as to which it shall be adjudged in such action, suit or proceeding that such person is liable for gross negligence, bad faith or intentional misconduct in duties; provided, however, that within sixty (60) days after the institution of such action, suit or proceeding, such person shall offer to the Company, in writing, the opportunity at its own expense to handle and defend the same.

4. SHARES SUBJECT TO PLAN.

4.1 Maximum Number of Shares Issuable. Subject to adjustment as provided in Section 4.2, the maximum aggregate number of shares of Stock that may be issued under the Plan shall be five million eighty-five thousand four hundred fifteen (5,085,415). If an outstanding Award for any reason expires or is terminated or canceled or if shares of Stock are acquired upon the exercise of an Award subject to a Company repurchase option and are repurchased by the Company at the Participant’s exercise or purchase price, the shares of Stock allocable to the unexercised portion of such Award or such repurchased shares of Stock shall again be available for sale or issuance under the Plan. Notwithstanding the foregoing, at any such time as the offer and sale of securities pursuant to the Plan is subject to compliance with Section 260.140.45 of Title 10 of the California Code of Regulations (“Section 260.140.45”), the total number of shares of Stock that can be issued or sold upon the exercise of all outstanding Awards (together with options outstanding under any other stock plan of the Company) and the total number of shares provided for under any stock bonus or similar plan of the Company shall not exceed thirty percent (30%) (or such other higher percentage limitation as may be approved by the stockholders of the Company pursuant to Section 260.140.45) of the then outstanding shares of the Company as calculated in accordance with the conditions and exclusions of Section 260.140.45.

4.2 Adjustments for Changes in Capital Structure. Subject to any required action by the stockholders of the Company, in the event of any change in the Stock effected without receipt of consideration by the Company, whether through merger, consolidation, reorganization, reincorporation, recapitalization, reclassification, stock dividend, stock split, reverse stock split, split-up, split-off, spin-off, combination of shares, exchange of shares, or similar change in the capital structure of the Company, or in the event of payment of a dividend or distribution to the stockholders of the Company in a form other than Stock (excepting normal cash dividends) that has a material effect on the Fair Market Value of shares of Stock, appropriate and proportionate adjustments shall be made in the number and class of shares subject to the Plan and to any outstanding Awards, in the ISO Share Limit set forth in Section 5.3(a), and in the exercise or purchase price per share of any outstanding Awards in order to prevent dilution or enlargement of Participants’ rights under the Plan. For purposes of the foregoing, conversion of any convertible securities of the Company shall not be treated as “effected without receipt of consideration by the Company.” If a majority of the shares which are of the same class as the shares that are subject to outstanding Awards are exchanged for, converted into, or otherwise become (whether or not pursuant to an Ownership Change Event) shares of another corporation (the “New Shares”), the Board or the Committee may unilaterally amend the outstanding Awards to provide that such Awards are for New Shares. In the event of any such amendment, the number of shares subject to, and the exercise or purchase price per share of, the outstanding Awards shall be adjusted in a fair and equitable manner as determined by the Board or the Committee, in their discretion. Any fractional share resulting from an

adjustment pursuant to this Section 4.2 shall be rounded down to the nearest whole number, and the exercise price per share shall be rounded up to the nearest whole cent. In no event may the exercise price of any Award be decreased to an amount less than the par value, if any, of the stock subject to the Award. Such adjustments shall be determined by the Board, and its determination shall be final, binding and conclusive.

5. ELIGIBILITY AND OPTION LIMITATIONS.

5.1 Persons Eligible for Awards. Awards may be granted only to Employees, Consultants and Directors.

5.2 Participation in Plan. Awards are granted solely at the discretion of the Board. Eligible persons may be granted more than one Award. However, eligibility in accordance with this Section shall not entitle any person to be granted an Award, or, having been granted an Award, to be granted an additional Award.

5.3 Incentive Stock Option Limitations.

(a) Maximum Number of Shares Issuable Pursuant to Incentive Stock Options. Subject to Section 4.1 and adjustment as provided in Section 4.2, the maximum aggregate number of shares of Stock that may be issued or sold under the Plan pursuant to the exercise of Incentive Stock Options shall not exceed seven million six hundred thousand (7,600,000) shares (the “ISO Share Limit”). The maximum aggregate number of shares of Stock that may be issued or sold under the Plan pursuant to all Awards other than Incentive Stock Options shall be the number of shares determined in accordance with Section 4.1, subject to adjustment as provided in Section 4.2.

(b) Persons Eligible. An Incentive Stock Option may be granted only to a person who, on the effective date of grant, is an Employee. Any person who is not an Employee on the effective date of the grant of an Option to such person may be granted only a Nonstatutory Stock Option. An Incentive Stock Option granted to a prospective Employee upon the condition that such person become an Employee shall be deemed granted effective on the date such person commences Service as an Employee, with an exercise price determined as of such date in accordance with Section 6.1.

(c) Fair Market Value Limitation. To the extent that options designated as Incentive Stock Options (granted under all stock plans of the Participating Company Group, including the Plan) become exercisable by a Participant for the first time during any calendar year for stock having a Fair Market Value greater than One Hundred Thousand Dollars ($100,000), the portions of such options which exceed such amount shall be treated as Nonstatutory Stock Options. For purposes of this Section 5.3, options designated as Incentive Stock Options shall be taken into account in the order in which they were granted, and the Fair Market Value of stock shall be determined as of the time the option with respect to such stock is granted. If the Code is amended to provide for a different limitation from that set forth in this Section, such different limitation shall be deemed incorporated herein effective as of the

date and with respect to such Options as required or permitted by such amendment to the Code. If an Option is treated as an Incentive Stock Option in part and as a Nonstatutory Stock Option in part by reason of the limitation set forth in this Section, the Participant may designate which portion of such Option the Participant is exercising. In the absence of such designation, the Participant shall be deemed to have exercised the Incentive Stock Option portion of the Option first. Separate certificates representing each such portion shall be issued upon the exercise of the Option.

6. TERMS AND CONDITIONS OF OPTIONS.

Options shall be evidenced by Award Agreements specifying the number of shares of Stock covered thereby, in such form as the Board shall from time to time establish. Award Agreements may incorporate all or any of the terms of the Plan by reference and shall comply with and be subject to the following terms and conditions:

6.1 Exercise Price. The exercise price for each Option shall be established in the discretion of the Board; provided, however, that (a) the exercise price per share for an Option shall be not less than the Fair Market Value of a share of Stock on the effective date of grant of the Option and (b) no Incentive Stock Option granted to a Ten Percent Stockholder shall have an exercise price per share less than one hundred ten percent (110%) of the Fair Market Value of a share of Stock on the effective date of grant of the Option. Notwithstanding the foregoing, an Option (whether an Incentive Stock Option or a Nonstatutory Stock Option) may be granted with an exercise price lower than the minimum exercise price set forth above if such Option is granted pursuant to an assumption or substitution for another option in a manner qualifying under the provisions of Section 424(a) of the Code.

6.2 Exercisability and Term of Options. Options shall be exercisable at such time or times, or upon such event or events, and subject to such terms, conditions, performance criteria and restrictions as shall be determined by the Board and set forth in the Award Agreement evidencing such Option; provided, however, that (a) no Option shall be exercisable after the expiration of ten (10) years after the effective date of grant of such Option, and (b) no Incentive Stock Option granted to a Ten Percent Stockholder shall be exercisable after the expiration of five (5) years after the effective date of grant of such Option. Subject to the foregoing, unless otherwise specified by the Board in the grant of an Option, any Option granted hereunder shall terminate ten (10) years after the effective date of grant of the Option, unless earlier terminated in accordance with its provisions.

6.3 Payment of Exercise Price.

(a) Forms of Consideration Authorized. Except as otherwise provided below, payment of the exercise price for the number of shares of Stock being purchased pursuant to any Option shall be made (i) in cash or by check or cash equivalent, (ii) by tender to the Company, or attestation to the ownership, of shares of Stock owned by the Participant having a Fair Market Value not less than the exercise price, (iii) by delivery of a properly executed notice together with irrevocable instructions to a broker providing for the assignment to the

Company of the proceeds of a sale or loan with respect to some or all of the shares being acquired upon the exercise of the Option (including, without limitation, through an exercise complying with the provisions of Regulation T as promulgated from time to time by the Board of Governors of the Federal Reserve System) (a “Cashless Exercise”), if a Cashless Exercise program has been established by the Board and is then in effect, (iv) by such other consideration as may be approved by the Board from time to time to the extent permitted by applicable law, or (v) by any combination thereof. The Board may at any time or from time to time, by approval of or by amendment to the standard forms of Award Agreement described in Section 8, or by other means, grant Options which do not permit all of the foregoing forms of consideration to be used in payment of the exercise price or which otherwise restrict one or more forms of consideration.

(b) Limitations on Forms of Consideration.

(i) Tender of Stock. Notwithstanding the foregoing, an Option may not be exercised by tender to the Company, or attestation to the ownership, of shares of Stock to the extent such tender or attestation would constitute a violation of the provisions of any law, regulation or agreement restricting the redemption of the Company’s stock. Unless otherwise provided by the Board, an Option may not be exercised by tender to the Company, or attestation to the ownership, of shares of Stock unless such shares either have been owned by the Participant for more than six (6) months (and were not used for another Option exercise by attestation during such period) or were not acquired, directly or indirectly, from the Company.

(ii) Cashless Exercise. The Company reserves, at any and all times, the right, in the Company’s sole and absolute discretion, to establish, decline to approve or terminate any program or procedures for the exercise of Options by means of a Cashless Exercise.

6.4 Effect of Termination of Service.

(a) Option Exercisability. Subject to earlier termination of the Option as otherwise provided by this Plan and unless a longer exercise period is provided by the Board and set forth in the Award Agreement, an Option shall terminate immediately upon the Participant’s termination of Service to the extent that it is then unvested and shall be exercisable after the Participant’s termination of Service to the extent it is then vested only during the applicable time period determined in accordance with this Section and thereafter shall terminate:

(i) Disability. If the Participant’s Service terminates because of the Disability of the Participant, the Option, to the extent unexercised and exercisable on the date on which the Participant’s Service terminated, may be exercised by the Participant (or the Participant’s guardian or legal representative) at any time prior to the expiration of twelve (12) months after the date on which the Participant’s Service terminated, but in any event no later than the date of expiration of the Option’s term as set forth in the Award Agreement evidencing such Option (the “Option Expiration Date”).

(ii) Death. If the Participant’s Service terminates because of the death of the Participant, the Option, to the extent unexercised and exercisable on the date on which the Participant’s Service terminated, may be exercised by the Participant’s legal representative or other person who acquired the right to exercise the Option by reason of the Participant’s death at any time prior to the expiration of twelve (12) months after the date on which the Participant’s Service terminated, but in any event no later than the Option Expiration Date. The Participant’s Service shall be deemed to have terminated on account of death if the Participant dies within three (3) months (or such longer period of time as determined by the Board, in its discretion and set forth in the Award Agreement) after the Participant’s termination of Service.

(iii) Termination for Cause. Notwithstanding any other provision of the Plan to the contrary, if the Participant’s Service with the Participating Company Group is terminated for Cause, the Option shall terminate and cease to be exercisable immediately upon such termination of Service.

(iv) Other Termination of Service. If the Participant’s Service terminates for any reason, except Disability, death or Cause, the Option, to the extent unexercised and exercisable by the Participant on the date on which the Participant’s Service terminated, may be exercised by the Participant at any time prior to the expiration of three (3) months after the date on which the Participant’s Service terminated (or such longer period of time as determined by the Board, in its discretion and set forth in the Award Agreement), but in any event no later than the Option Expiration Date.

(b) Extension if Exercise Prevented by Law. Notwithstanding the foregoing other than termination for Cause, if the exercise of an Option within the applicable time periods set forth in Section 6.4(a) is prevented by the provisions of Section 11 below, the Option shall remain exercisable until thirty (30) days after the date such exercise first would no longer be prevented by such provisions, but in any event no later than the Option Expiration Date.

6.5 Transferability of Options. During the lifetime of the Participant, an Option shall be exercisable only by the Participant or the Participant’s guardian or legal representative. No Option shall be assignable or transferable by the Participant, except by will or by the laws of descent and distribution. Notwithstanding the foregoing, to the extent permitted by the Board, in its discretion, and set forth in the Award Agreement evidencing such Option, a Nonstatutory Stock Option shall be assignable or transferable subject to the applicable limitations, if any, described in Section 260.140.41 of Title 10 of the California Code of Regulations, Rule 701 under the Securities Act, and the General Instructions to Form S-8 Registration Statement under the Securities Act.

7. TERMS AND CONDITIONS OF STOCK PURCHASE RIGHTS.

Stock Purchase Rights shall be evidenced by Award Agreements, specifying the number of shares of Stock covered thereby, in such form as the Board shall from time to time establish. Award Agreements may incorporate all or any of the terms of the Plan by reference and shall comply with and be subject to the following terms and conditions:

7.1 Purchase Price. The purchase price under each Stock Purchase Right shall be established by the Board; provided, however, the purchase price per share under a Stock Purchase Right shall be at least one hundred percent (100%) of the Fair Market Value of a share of Stock either on the effective date of grant of the Stock Purchase Right or on the date on which the purchase is consummated.

7.2 Purchase Period. A Stock Purchase Right shall be exercisable within a period established by the Board, which shall in no event exceed thirty (30) days from the effective date of the grant of the Stock Purchase Right.

7.3 Payment of Purchase Price. Except as otherwise provided below, payment of the purchase price for the number of shares of Stock being purchased pursuant to any Stock Purchase Right shall be made (a) in cash or by check or cash equivalent, (b) in the form of the Participant’s past service rendered to a Participating Company or for its benefit having a value not less than the aggregate purchase price of the shares being acquired, (c) by such other consideration as may be approved by the Board from time to time to the extent permitted by applicable law, or (d) by any combination thereof. The Board may at any time or from time to time, by adoption of or by amendment to the standard form of Award Agreement described in Section 8, or by other means, grant Stock Purchase Rights which do not permit all of the foregoing forms of consideration to be used in payment of the purchase price or which otherwise restrict one or more forms of consideration.

7.4 Vesting and Restrictions on Transfer. Shares issued pursuant to any Stock Purchase Right may or may not be made subject to vesting conditioned upon the satisfaction of such Service requirements, conditions, restrictions or performance criteria (the “Vesting Conditions”) as shall be established by the Board and set forth in the Award Agreement evidencing such Award. During any period (the “Restriction Period”) in which shares acquired pursuant to a Stock Purchase Right remain subject to Vesting Conditions, such shares may not be sold, exchanged, transferred, pledged, assigned or otherwise disposed of other than pursuant to an Ownership Change Event or as provided in Section 7.5. Upon request by the Company, each Participant shall execute any agreement evidencing such transfer restrictions prior to the receipt of shares of Stock hereunder and shall promptly present to the Company any and all certificates representing shares of Stock acquired hereunder for the placement on such certificates of appropriate legends evidencing any such transfer restrictions.

7.5 Effect of Termination of Service. Unless otherwise provided by the Board in the grant of a Stock Purchase Right and set forth in the Award Agreement, if a Participant’s Service terminates for any reason, whether voluntary or involuntary (including the Participant’s death or disability), then the Company shall have the option to repurchase for the purchase price paid by the Participant any shares acquired by the Participant pursuant to a Stock Purchase Right which remain subject to Vesting Conditions as of the date of the Participant’s termination of Service. The Company shall have the right to assign at any time any repurchase right it may have, whether or not such right is then exercisable, to one or more persons as may be selected by the Company.

7.6 Nontransferability of Stock Purchase Rights. Rights to acquire shares of Stock pursuant to a Stock Purchase Right may not be assigned or transferred in any manner except by will or the laws of descent and distribution, and, during the lifetime of the Participant, shall be exercisable only by the Participant.

8. STANDARD FORMS OF AWARD AGREEMENTS.

8.1 Award Agreements. Each Award shall comply with and be subject to the terms and conditions set forth in the appropriate form of Award Agreement approved by the Board and as amended from time to time. No Award or purported Award shall be a valid and binding obligation of the Company unless evidenced by a fully executed Award Agreement. Any Award Agreement may consist of an appropriate form of Notice of Grant and a form of Agreement incorporated therein by reference, or such other form or forms, including electronic media, as the Board or the Committee may approve from time to time.

8.2 Authority to Vary Terms. The Board shall have the authority from time to time to vary the terms of any standard form of Award Agreement either in connection with the grant or amendment of an individual Award or in connection with the authorization of a new standard form or forms; provided, however, that the terms and conditions of any such new, revised or amended standard form or forms of Award Agreement are not inconsistent with the terms of the Plan.

9. CHANGE IN CONTROL.

9.1 Effect of Change in Control on Awards.

(a) Accelerated Vesting. The Board may, in its sole discretion, provide in any Award Agreement or, in the event of a Change in Control, may take such actions as it deems appropriate to provide for the acceleration of the exercisability and vesting in connection with such Change in Control of any or all outstanding Awards and shares acquired upon the exercise thereof upon such conditions, including termination of the Participant’s Service prior to, upon, or following such Change in Control, and to such extent as the Board shall determine.

(b) Assumption or Substitution of Awards. In the event of a Change in Control, the surviving, continuing, successor, or purchasing corporation or other business entity or parent thereof, as the case may be (the “Acquiror”), may, without the consent of any Participant, either assume or continue the Company’s rights and obligations under each or any Award or portion thereof outstanding immediately prior to the Change in Control or substitute for each or any such outstanding Award or portion thereof a substantially equivalent award for the Acquiror’s stock. For purposes of this Section, an Award shall be deemed assumed if, following the Change in Control, the Award confers the right to receive, subject to the terms and

conditions of the Plan and the applicable Award Agreement, for each share of Stock subject to the Award immediately prior to the Change in Control, the consideration (whether stock, cash, other securities or property or a combination thereof) to which a holder of a share of Stock on the effective date of the Change in Control was entitled; provided, however, that if such consideration is not solely common stock of the Acquiror, the Board may, with the consent of the Acquiror, provide for the consideration to be received upon the exercise of the Award, for each share of Stock subject to the Award, to consist solely of common stock of the Acquiror equal in Fair Market Value to the per share consideration received by holders of Stock pursuant to the Change in Control. Any Award or portions thereof which are neither assumed or continued by the Acquiror in connection with the Change in Control nor exercised as of the time of consummation of the Change in Control shall terminate and cease to be outstanding effective as of the time of consummation of the Change in Control. Notwithstanding the foregoing, shares acquired upon exercise of an Award prior to the Change in Control and any consideration received pursuant to the Change in Control with respect to such shares shall continue to be subject to all applicable provisions of the Award Agreement evidencing such Award except as otherwise provided in such Award Agreement.

(c) Cash-Out of Awards. The Board may, in its sole discretion and without the consent of any Participant, determine that, upon the occurrence of a Change in Control, each or any Award outstanding immediately prior to the Change in Control shall be canceled in exchange for a payment with respect to each vested share (and each unvested share, if so determined by the Board) of Stock subject to such canceled Award in (i) cash, (ii) stock of the Company or of a corporation or other business entity a party to the Change in Control, or (iii) other property which, in any such case, shall be in an amount having a Fair Market Value equal to the Fair Market Value of the consideration to be paid per share of Stock in the Change in Control over the exercise price per share under such Award (the “Spread”). In the event such determination is made by the Board, the Spread (reduced by applicable withholding taxes, if any) shall be paid to Participants in respect of their canceled Awards as soon as practicable following the date of the Change in Control and in respect of the unvested portion of their canceled Awards in accordance with the vesting schedule applicable to such Awards as in effect prior to the Change in Control.

9.2 Federal Excise Tax Under Section 4999 of the Code.

(a) Excess Parachute Payment. In the event that any acceleration of vesting pursuant to an Award and any other payment or benefit received or to be received by a Participant would subject the Participant to any excise tax pursuant to Section 4999 of the Code due to the characterization of such acceleration of vesting, payment or benefit as an “excess parachute payment” under Section 280G of the Code, the Participant may elect, in his or her sole discretion, to reduce the amount of any acceleration of vesting called for under the Award in order to avoid such characterization.

(b) Determination by Independent Accountants. To aid the Participant in making any election called for under Section 9.2(a), no later than the date of the occurrence of any event that might reasonably be anticipated to result in an “excess parachute payment” to the Participant as described in Section 9.2(a), the Company shall request a determination in writing by independent public accountants selected by the Company (the “Accountants”). As soon as practicable thereafter, the Accountants shall determine and report to the Company and the Participant the amount of such acceleration of vesting, payments and benefits which would produce the greatest after-tax benefit to the Participant. For the purposes of such determination, the Accountants may rely on reasonable, good faith interpretations concerning the application of Sections 280G and 4999 of the Code. The Company and the Participant shall furnish to the Accountants such information and documents as the Accountants may reasonably request in order to make their required determination. The Company shall bear all fees and expenses the Accountants may reasonably charge in connection with their services contemplated by this Section 9.2(b).

10. TAX WITHHOLDING.

10.1 Tax Withholding in General. The Company shall have the right to deduct from any and all payments made under the Plan, or to require the Participant, through payroll withholding, cash payment or otherwise, including by means of a Cashless Exercise of an Option, to make adequate provision for, the federal, state, local and foreign taxes, if any, required by law to be withheld by the Participating Company Group with respect to an Award or the shares acquired pursuant thereto. The Company shall have no obligation to deliver shares of Stock or to release shares of Stock from an escrow established pursuant to an Award Agreement until the Participating Company Group’s tax withholding obligations have been satisfied by the Participant.

10.2 Withholding in Shares. The Company shall have the right, but not the obligation, to deduct from the shares of Stock issuable to a Participant upon the exercise of an Award, or to accept from the Participant the tender of, a number of whole shares of Stock having a Fair Market Value, as determined by the Company, equal to all or any part of the tax withholding obligations of the Participating Company Group. The Fair Market Value of any shares of Stock withheld or tendered to satisfy any such tax withholding obligations shall not exceed the amount determined by the applicable minimum statutory withholding rates.

11. COMPLIANCE WITH SECURITIES LAW; SECTION 409A.

The grant of Awards and the issuance or sale of shares of Stock upon exercise of Awards shall be subject to compliance with all applicable requirements of federal, state and foreign law with respect to such securities. Awards may not be exercised if the issuance of shares of Stock upon exercise would constitute a violation of any applicable federal, state or foreign securities laws or other law or regulations or the requirements of any stock exchange or market system upon which the Stock may then be listed. In addition, no Award may be exercised unless (a) a registration statement under the Securities Act shall at the time of exercise of the Award be in effect with respect to the shares issuable upon exercise of the Award or (b) in the opinion of legal counsel to the Company, the shares issuable upon exercise of the Award may be issued in accordance with the terms of an applicable exemption from the registration

requirements of the Securities Act. The inability of the Company to obtain from any regulatory body having jurisdiction the authority, if any, deemed by the Company’s legal counsel to be necessary to the lawful issuance and sale of any shares hereunder shall relieve the Company of any liability in respect of the failure to issue or sell such shares as to which such requisite authority shall not have been obtained. As a condition to the exercise of any Award, the Company may require the Participant to satisfy any qualifications that may be necessary or appropriate, to evidence compliance with any applicable law or regulation and to make any representation or warranty with respect thereto as may be requested by the Company. Every Award granted pursuant to this Plan is intended to not constitute or provide for a “deferral of compensation,” with the meaning of Section 1.409A-1(b) of the Treasury Regulations. Any provision of this Plan or of an Award Agreement which is inconsistent with any of the requirements for an Award to not constitute or provide for a “deferral of compensation” shall, without further act or amendment by the Company, Committee or the Board, be reformed to comply with the applicable requirement.

12. AMENDMENT OR TERMINATION OF PLAN.

The Board may amend, suspend or terminate the Plan at any time. However, subject to changes in applicable law, regulations or rules that would permit otherwise, without the approval of the Company’s stockholders, there shall be (a) no increase in the maximum aggregate number of shares of Stock that may be issued under the Plan (except by operation of the provisions of Section 4.2), (b) no change in the class of persons eligible to receive Incentive Stock Options, and (c) no other amendment of the Plan that would require approval of the Company’s stockholders under any applicable law, regulation or rule, including the rules of any stock exchange or market system upon which the Stock may then be listed. No amendment, suspension or termination of the Plan shall affect any then outstanding Award unless expressly provided by the Board. Except as provided by the next sentence, no amendment, suspension or termination of the Plan may adversely affect any then outstanding Award without the consent of the Participant. Notwithstanding any other provision of the Plan to the contrary, the Board may, in its sole and absolute discretion and without the consent of any participant, amend the Plan or any Award Agreement, to take effect retroactively or otherwise, as it deems necessary or advisable for the purpose of conforming the Plan or such Award Agreement to any present or future law, regulation or rule applicable to the Plan, including, but not limited to, Section 409A of the Code.

13. MISCELLANEOUS PROVISIONS.

13.1 Repurchase Rights. Shares issued or sold under the Plan may be subject to a right of first refusal, one or more repurchase options, or other conditions and restrictions as determined by the Board in its discretion at the time the Award is granted. The Company shall have the right to assign at any time any repurchase right it may have, whether or not such right is then exercisable, to one or more persons as may be selected by the Company. Upon request by the Company, each Participant shall execute any agreement evidencing such transfer restrictions prior to the receipt of shares of Stock hereunder and shall promptly present to the Company any and all certificates representing shares of Stock acquired hereunder for the placement on such certificates of appropriate legends evidencing any such transfer restrictions.

13.2 Provision of Information. To the extent required by applicable law, at least annually, copies of the Company’s balance sheet and income statement for the just completed fiscal year shall be made available to each Participant and purchaser of shares of Stock upon the exercise of an Award. The Company shall not be required to provide such information to key employees whose duties in connection with the Company assure them access to equivalent information. Furthermore, the Company shall deliver to each Participant such disclosures as are required in accordance with Rule 701 under the Securities Act.

13.3 Rights as Employee, Consultant or Director. No person, even though eligible pursuant to Section 5, shall have a right to be selected as a Participant, or, having been so selected, to be selected again as a Participant. Nothing in the Plan or any Award granted under the Plan shall confer on any Participant a right to remain an Employee, Consultant or Director or interfere with or limit in any way any right of a Participating Company to terminate the Participant’s Service at any time. To the extent that an Employee of a Participating Company other than the Company receives an Award under the Plan, that Award shall in no event be understood or interpreted to mean that the Company is the Employee’s employer or that the Employee has an employment relationship with the Company.

13.4 Rights as a Stockholder. A Participant shall have no rights as a stockholder with respect to any shares covered by an Award until the date of the issuance or sale of such shares (as evidenced by the appropriate entry on the books of the Company or of a duly authorized transfer agent of the Company). No adjustment shall be made for dividends, distributions or other rights for which the record date is prior to the date such shares are sold or issued, except as provided in Section 4.2 or another provision of the Plan.

13.5 Fractional Shares. The Company shall not be required to issue or sell fractional shares upon the exercise or settlement of any Award.

13.6 Retirement and Welfare Plans. Neither Awards made under this Plan nor shares of Stock or cash paid pursuant to such Awards shall be included as “compensation” for purposes of computing the benefits payable to any Participant under any Participating Company’s retirement plans (both qualified and non-qualified) or welfare benefit plans unless such other plan provides that such compensation shall be taken into account in computing such benefits.

13.7 Severability. If any one or more of the provisions (or any part thereof) of this Plan shall be held invalid, illegal or unenforceable in any respect, such provision shall be modified so as to make it valid, legal and enforceable, and the validity, legality and enforceability of the remaining provisions (or any part thereof) of the Plan shall not in any way be affected or impaired thereby.

13.8 No Constraint on Corporate Action. Nothing in this Plan shall be construed to: (a) limit, impair, or otherwise affect the Company’s or another Participating Company’s right or power to make adjustments, reclassifications, reorganizations, or changes of its capital or business structure, or to merge or consolidate, or dissolve, liquidate, sell, or transfer all or any part of its business or assets; or (b) limit the right or power of the Company or another Participating Company to take any action which such entity deems to be necessary or appropriate.

13.9 Choice of Law. Except to the extent governed by applicable federal law, the validity, interpretation, construction and performance of the Plan and each Award Agreement shall be governed by the laws of the State of California, without regard to its conflict of law rules.

13.10 Stockholder Approval. The Plan or any increase in the maximum aggregate number of shares of Stock issuable thereunder as provided in Section 4.1 (the “Authorized Shares”) shall be approved by a majority of the outstanding securities of the Company entitled to vote within twelve (12) months before or after the date of adoption thereof by the Board. Awards granted prior to security holder approval of the Plan or in excess of the Authorized Shares previously approved by the security holders shall become exercisable no earlier than the date of security holder approval of the Plan or such increase in the Authorized Shares, as the case may be.

13.11 Date of Grant. The date of grant of an Award will be the date on which all corporate actions necessary to create the legally binding right creating the Option have been taken, determined in accordance with Section 1.409A-1(b)(5)(vi)(B) of the Treasury Regulations to the extent applicable.

IGM BIOSCIENCES, INC.

AMENDED AND RESTATED

STOCK OPTION AGREEMENT

IGM Biosciences, Inc. has granted to the individual (the “Participant”) named in the Notice of Grant of Stock Option (the “Notice”) to which this Stock Option Agreement (the “Option Agreement”) is attached an option (the “Option”) to purchase certain shares of Stock upon the terms and conditions set forth in the Notice and this Option Agreement. The Option has been granted pursuant to and shall in all respects be subject to the terms and conditions of the IGM Biosciences, Inc. 2010 Stock Plan (the “Plan”), as amended, the provisions of which are incorporated herein by reference. By signing the Notice, the Participant: (a) represents that the Participant has received copies of, and has read and is familiar with the terms and conditions of, the Notice, the Plan and this Option Agreement, (b) accepts the Option subject to all of the terms and conditions of the Notice, the Plan and this Option Agreement, and (c) agrees to accept as binding, conclusive and final all decisions or interpretations of the Board upon any questions arising under the Notice, the Plan or this Option Agreement.

1. DEFINITIONS AND CONSTRUCTION.

1.1 Definitions. Unless otherwise defined herein, capitalized terms shall have the meanings assigned to such terms in the Notice or the Plan.

1.2 Construction. Captions and titles contained herein are for convenience only and shall not affect the meaning or interpretation of any provision of this Option Agreement. Except when otherwise indicated by the context, the singular shall include the plural and the plural shall include the singular. Use of the term “or” is not intended to be exclusive, unless the context clearly requires otherwise.

2. TAX CONSEQUENCES.

2.1 Tax Status of Option. This Option is intended to have the tax status designated in the Notice.

(a) Incentive Stock Option. If the Notice so designates, this Option is intended to be an Incentive Stock Option within the meaning of Section 422(b) of the Code, but the Company does not represent or warrant that this Option qualifies as such. The Participant should consult with the Participant’s own tax advisor regarding the tax effects of this Option and the requirements necessary to obtain favorable income tax treatment under Section 422 of the Code, including, but not limited to, holding period requirements. (NOTE TO PARTICIPANT: If the Option is exercised more than three (3) months after the date on which you cease to be an Employee (other than by reason of your death or permanent and total disability as defined in Section 22(e)(3) of the Code), the Option will be treated as a Nonstatutory Stock Option and not as an Incentive Stock Option to the extent required by Section 422 of the Code.)

(b) Nonstatutory Stock Option. If the Notice so designates, this Option is intended to be a Nonstatutory Stock Option and shall not be treated as an Incentive Stock Option within the meaning of Section 422(b) of the Code.

2.2 ISO Fair Market Value Limitation. If the Notice designates this Option as an Incentive Stock Option, then to the extent that the Option (together with all Incentive Stock Options granted to the Participant under all stock option plans of the Participating Company Group, including the Plan) becomes exercisable for the first time during any calendar year for shares having a Fair Market Value greater than One Hundred Thousand Dollars ($100,000), the portion of such options which exceeds such amount will be treated as Nonstatutory Stock Options. For purposes of this Section 2.2, options designated as Incentive Stock Options are taken into account in the order in which they were granted, and the Fair Market Value of stock is determined as of the time the option with respect to such stock is granted. If the Code is amended to provide for a different limitation from that set forth in this Section 2.2, such different limitation shall be deemed incorporated herein effective as of the date required or permitted by such amendment to the Code. If the Option is treated as an Incentive Stock Option in part and as a Nonstatutory Stock Option in part by reason of the limitation set forth in this Section 2.2, the Participant may designate which portion of such Option the Participant is exercising. In the absence of such designation, the Participant shall be deemed to have exercised the Incentive Stock Option portion of the Option first. Separate certificates representing each such portion shall be issued upon the exercise of the Option. (NOTE TO PARTICIPANT: If the aggregate Exercise Price of the Option (that is, the Exercise Price multiplied by the Number of Option Shares) plus the aggregate exercise price of any other Incentive Stock Options you hold (whether granted pursuant to the Plan or any other stock option plan of the Participating Company Group) is greater than $100,000, you should contact the Chief Financial Officer of the Company to ascertain whether the entire Option qualifies as an Incentive Stock Option.)

3. ADMINISTRATION.

All questions of interpretation concerning this Option Agreement shall be determined by the Board. All determinations by the Board shall be final and binding upon all persons having an interest in the Option. Any Officer shall have the authority to act on behalf of the Company with respect to any matter, right, obligation, or election which is the responsibility of or which is allocated to the Company herein, provided the Officer has apparent authority with respect to such matter, right, obligation, or election.

4. EXERCISE OF THE OPTION.

4.1 Right to Exercise. Except as otherwise provided herein, the Option shall be exercisable on and after the Initial Vesting Date and prior to the termination of the Option (as provided in Section 6) in an amount not to exceed the number of Vested Shares less the number of shares previously acquired upon exercise of the Option, subject to the Company’s repurchase rights set forth in Section 11. In no event shall the Option be exercisable for more shares than the Number of Option Shares, as adjusted pursuant to Section 9.

4.2 Method of Exercise. Exercise of the Option shall be by written notice to the Company which must state the election to exercise the Option, the number of whole shares of Stock for which the Option is being exercised and such other representations and agreements as to the Participant’s investment intent with respect to such shares as may be required pursuant to the provisions of this Option Agreement. The written notice must be signed by the Participant and must be delivered in person, by certified or registered mail, return receipt requested, by confirmed facsimile transmission, or by such other means as the Company may permit, to the Chief Financial Officer of the Company, or other authorized representative of the Participating Company Group, prior to the termination of the Option as set forth in Section 6, accompanied by full payment of the aggregate Exercise Price for the number of shares of Stock being purchased. The Option shall be deemed to be exercised upon receipt by the Company of such written notice and the aggregate Exercise Price.

4.3 Payment of Exercise Price.

(a) Forms of Consideration Authorized. Except as otherwise provided below, payment of the aggregate Exercise Price for the number of shares of Stock for which the Option is being exercised shall be made (i) in cash, by check, or cash equivalent, (ii) by tender to the Company, or attestation to the ownership, of whole shares of Stock owned by the Participant having a Fair Market Value not less than the aggregate Exercise Price, (iii) by means of a Cashless Exercise, as defined in Section 4.3(b), if a Cashless Exercise program has been established by the Board and is then in effect, or (iv) by any combination of the foregoing.

(b) Limitations on Forms of Consideration.

(i) Tender of Stock. Notwithstanding the foregoing, the Option may not be exercised by tender to the Company, or attestation to the ownership, of shares of Stock to the extent such tender or attestation would constitute a violation of the provisions of any law, regulation or agreement restricting the redemption of the Company’s stock. The Option may not be exercised by tender to the Company, or attestation to the ownership, of shares of Stock unless such shares either have been owned by the Participant for more than six (6) months (and not used for another option exercise by attestation during such period) or were not acquired, directly or indirectly, from the Company.

(ii) Cashless Exercise. A “Cashless Exercise” means the delivery of a properly executed notice together with irrevocable instructions to a broker in a form acceptable to the Company providing for the assignment to the Company of the proceeds of a sale or loan with respect to some or all of the shares of Stock acquired upon the exercise of the Option pursuant to a program or procedure approved by the Company (including, without limitation, through an exercise complying with the provisions of Regulation T as promulgated from time to time by the Board of Governors of the Federal Reserve System). The Company reserves, at any and all times, the right, in the Company’s sole and absolute discretion, to decline to approve or terminate any such program or procedure.

4.4 Tax Withholding. At the time the Option is exercised, in whole or in part, or at any time thereafter as requested by the Company, the Participant hereby authorizes withholding from payroll and any other amounts payable to the Participant, and otherwise agrees to make adequate provision for (including by means of a Cashless Exercise to the extent permitted by the Company), any sums required to satisfy the federal, state, local and foreign tax withholding obligations of the Participating Company Group, if any, which arise in connection with the Option, including, without limitation, obligations arising upon (i) the exercise, in whole or in part, of the Option or (ii) the transfer, in whole or in part, of any shares acquired upon exercise of the Option. The Option is not exercisable unless the tax withholding obligations of the Participating Company Group are satisfied. Accordingly, the Company shall have no obligation to deliver shares of Stock until the tax withholding obligations of the Participating Company Group have been satisfied by the Participant.

4.5 Certificate Registration. Except in the event the Exercise Price is paid by means of a Cashless Exercise, the certificate (if any) for the shares as to which the Option is exercised shall be registered in the name of the Participant, or, if applicable, in the names of the heirs of the Participant.

4.6 Restrictions on Grant of the Option and Issuance or Sale of Shares. The grant of the Option and the issuance or sale of shares of Stock upon exercise of the Option shall be subject to compliance with all applicable requirements of federal, state or foreign law with respect to such securities. The Option may not be exercised if the issuance or sale of shares of Stock upon exercise would constitute a violation of any applicable federal, state or foreign securities laws or other law or regulations or the requirements of any stock exchange or market system upon which the Stock may then be listed. In addition, the Option may not be exercised unless (i) a registration statement under the Securities Act shall at the time of exercise of the Option be in effect with respect to the shares to be issued or sold upon exercise of the Option or (ii) in the opinion of legal counsel to the Company, the shares to be issued or sold upon exercise of the Option may be issued or sold in accordance with the terms of an applicable exemption from the registration requirements of the Securities Act. THE PARTICIPANT IS CAUTIONED THAT THE OPTION MAY NOT BE EXERCISED UNLESS THE FOREGOING CONDITIONS ARE SATISFIED. ACCORDINGLY, THE PARTICIPANT MAY NOT BE ABLE TO EXERCISE THE OPTION WHEN DESIRED EVEN THOUGH THE OPTION IS VESTED. The inability of the Company to obtain from any regulatory body having jurisdiction the authority, if any, deemed by the Company’s legal counsel to be necessary to the lawful issuance and sale of any shares subject to the Option shall relieve the Company of any liability in respect of the failure to issue or sell such shares as to which such requisite authority shall not have been obtained. As a condition to the exercise of the Option, the Company may require the Participant to satisfy any qualifications that may be necessary or appropriate, to evidence compliance with any applicable law or regulation and to make any representation or warranty with respect thereto as may be requested by the Company.

4.7 Fractional Shares. The Company shall not be required to issue or sell fractional shares upon the exercise of the Option.

5. NONTRANSFERABILITY OF THE OPTION.

The Option may be exercised during the lifetime of the Participant only by the Participant or the Participant’s guardian or legal representative and may not be assigned or transferred in any manner except by will or by the laws of descent and distribution. Following the death of the Participant, the Option, to the extent provided in Section 7, may be exercised by the Participant’s legal representative or by any person empowered to do so under the deceased Participant’s will or under the then applicable laws of descent and distribution.

6. TERMINATION OF THE OPTION.

The Option shall terminate and may no longer be exercised after the first to occur of (a) the Option Expiration Date, (b) the last date for exercising the Option following termination of the Participant’s Service as described in Section 7, or (c) a Change in Control to the extent provided in Section 8.

7. EFFECT OF TERMINATION OF SERVICE.

7.1 Option Exercisability.

(a) Disability. If the Participant’s Service terminates because of the Disability of the Participant, the Option, to the extent unexercised and exercisable on the date on which the Participant’s Service terminated, may be exercised by the Participant (or the Participant’s guardian or legal representative) at any time prior to the expiration of twelve (12) months (or such other longer period of time as determined by the Board, in its discretion) after the date on which the Participant’s Service terminated, but in any event no later than the Option Expiration Date.

(b) Death. If the Participant’s Service terminates because of the death of the Participant, the Option, to the extent unexercised and exercisable on the date on which the Participant’s Service terminated, may be exercised by the Participant’s legal representative or other person who acquired the right to exercise the Option by reason of the Participant’s death at any time prior to the expiration of twelve (12) months (or such other longer period of time as determined by the Board, in its discretion) after the date on which the Participant’s Service terminated, but in any event no later than the Option Expiration Date. The Participant’s Service shall be deemed to have terminated on account of death if the Participant dies within three (3) months after the Participant’s termination of Service.

(c) Other Termination of Service. If the Participant’s Service with the Participating Company Group terminates for any reason, except Disability or death, the Option, to the extent unexercised and exercisable by the Participant on the date on which the Participant’s Service terminated, may be exercised by the Participant at any time prior to the expiration of three (3) months (or such other longer period of time as determined by the Board, in its discretion) after the date on which the Participant’s Service terminated, but in any event no later than the Option Expiration Date.

7.2 Extension if Exercise Prevented by Law. Notwithstanding the foregoing, if the exercise of the Option within the applicable time periods set forth in Section 7.1 is prevented by the provisions of Section 4.6, the Option shall remain exercisable until three (3) months after the date the Participant is notified by the Company that the Option is exercisable, but in any event no later than the Option Expiration Date.

7.3 Extension if Participant Subject to Section 16(b). Notwithstanding the foregoing, if a sale within the applicable time periods set forth in Section 7.1 of shares acquired upon the exercise of the Option would subject the Participant to suit under Section 16(b) of the Exchange Act, the Option shall remain exercisable until the earliest to occur of (i) the tenth (10th) day following the date on which a sale of such shares by the Participant would no longer be subject to such suit, (ii) the one hundred and ninetieth (190th) day after the Participant’s termination of Service, or (iii) the Option Expiration Date.

8. CHANGE IN CONTROL.

In the event of a Change in Control, the Acquiring Corporation may, without the consent of the Participant, either assume the Company’s rights and obligations under the Option or substitute for the Option a substantially equivalent option for the Acquiring Corporation’s stock. The Option shall terminate and cease to be outstanding effective as of the date of the Change in Control to the extent that the Option is neither assumed or substituted for by the Acquiring Corporation in connection with the Change in Control nor exercised as of the date of the Change in Control. Notwithstanding the foregoing, shares acquired upon exercise of the Option prior to the Change in Control and any consideration received pursuant to the Change in Control with respect to such shares shall continue to be subject to all applicable provisions of this Option Agreement except as otherwise provided herein.

9. ADJUSTMENTS FOR CHANGES IN CAPITAL STRUCTURE.

Subject to any required action by the stockholders of the Company, in the event of any change in the Stock effected without receipt of consideration by the Company, whether through merger, consolidation, reorganization, reincorporation, recapitalization, reclassification, stock dividend, stock split, reverse stock split, split-up, split-off, spin-off, combination of shares, exchange of shares, or similar change in the capital structure of the Company, or in the event of payment of a dividend or distribution to the stockholders of the Company in a form other than Stock (excepting normal cash dividends) that has a material effect on the Fair Market Value of shares of Stock, appropriate and proportionate adjustments shall be made in the number, Exercise Price and class of shares subject to the Option, in order to prevent dilution or enlargement of the Participant’s rights under the Option. For purposes of the foregoing, conversion of any convertible securities of the Company shall not be treated as “effected without receipt of consideration by the Company.” Any fractional share resulting from an adjustment pursuant to this Section 9 shall be rounded down to the nearest whole number, and in no event may the Exercise Price of the Option be decreased to an amount less than the par value, if any, of the stock subject to the Option. Such adjustments shall be determined by the Board, and its determination shall be final, binding and conclusive.

10. RIGHTS AS A STOCKHOLDER, EMPLOYEE OR CONSULTANT.

The Participant shall have no rights as a stockholder with respect to any shares covered by the Option until the date of the issuance of a certificate for the shares or the transfer of the shares for which the Option has been exercised (as evidenced by the appropriate entry on the books of the Company or of a duly authorized transfer agent of the Company). No adjustment shall be made for dividends, distributions or other rights for which the record date is prior to the date such certificate is issued or transfer is entered, except as provided in Section 9. If the Participant is an Employee, the Participant understands and acknowledges that, except as otherwise provided in a separate, written employment agreement between a Participating Company and the Participant, the Participant’s employment is “at will” and is for no specified term. Nothing in this Option Agreement shall confer upon the Participant any right to continue in the Service of a Participating Company or interfere in any way with any right of the Participating Company Group to terminate the Participant’s Service as an Employee or Consultant, as the case may be, at any time.

11. RIGHT OF FIRST REFUSAL.

11.1 Grant of Right of First Refusal. Except as provided in Section 11.7 below, in the event the Participant, the Participant’s legal representative, or other holder of shares acquired upon exercise of the Option proposes to sell, exchange, transfer, pledge, or otherwise dispose of any shares acquired upon exercise of the Option (the “Transfer Shares”) to any person or entity, including, without limitation, any stockholder of a Participating Company, the Company shall have the right to purchase the Transfer Shares under the terms and subject to the conditions set forth in this Section 11 (the “Right of First Refusal”).

11.2 Notice of Proposed Transfer. Prior to any proposed transfer of the Transfer Shares, the Participant shall deliver written notice (the “Transfer Notice”) to the Company describing fully the proposed transfer, including the number of Transfer Shares, the name and address of the proposed transferee (the “Proposed Transferee”) and, if the transfer is voluntary, the proposed transfer price, and containing such information necessary to show the bona fide nature of the proposed transfer. In the event of a bona fide gift or involuntary transfer, the proposed transfer price shall be deemed to be the Fair Market Value of the Transfer Shares, as determined by the Board in good faith. If the Participant proposes to transfer any Transfer Shares to more than one Proposed Transferee, the Participant shall provide a separate Transfer Notice for the proposed transfer to each Proposed Transferee. The Transfer Notice shall be signed by both the Participant and the Proposed Transferee and must constitute a binding commitment of the Participant and the Proposed Transferee for the transfer of the Transfer Shares to the Proposed Transferee subject only to the Right of First Refusal.

11.3 Bona Fide Transfer. If the Company determines that the information provided by the Participant in the Transfer Notice is insufficient to establish the bona fide nature of a proposed voluntary transfer, the Company shall give the Participant written notice of the Participant’s failure to comply with the procedure described in this Section 11, and the Participant shall have no right to transfer the Transfer Shares without first complying with the procedure described in this Section 11. The Participant shall not be permitted to transfer the Transfer Shares if the proposed transfer is not bona fide.

11.4 Exercise of Right of First Refusal. If the Company determines the proposed transfer to be bona fide, the Company shall have the right to purchase all, but not less than all, of the Transfer Shares (except as the Company and the Participant otherwise agree) at the purchase price and on the terms set forth in the Transfer Notice by delivery to the Participant of a notice of exercise of the Right of First Refusal within thirty (30) days after the date the Transfer Notice is delivered to the Company. The Company’s exercise or failure to exercise the Right of First Refusal with respect to any proposed transfer described in a Transfer Notice shall not affect the Company’s right to exercise the Right of First Refusal with respect to any proposed transfer described in any other Transfer Notice, whether or not such other Transfer Notice is issued by the Participant or issued by a person other than the Participant with respect to a proposed transfer to the same Proposed Transferee. If the Company exercises the Right of First Refusal, the Company and the Participant shall thereupon consummate the sale of the Transfer Shares to the Company on the terms set forth in the Transfer Notice within sixty (60) days after the date the Transfer Notice is delivered to the Company (unless a longer period is offered by the Proposed Transferee); provided, however, that in the event the Transfer Notice provides for the payment for the Transfer Shares other than in cash, the Company shall have the option of paying for the Transfer Shares by the present value cash equivalent of the consideration described in the Transfer Notice as reasonably determined by the Company. For purposes of the foregoing, cancellation of any indebtedness of the Participant to any Participating Company shall be treated as payment to the Participant in cash to the extent of the unpaid principal and any accrued interest canceled.

11.5 Failure to Exercise Right of First Refusal. If the Company fails to exercise the Right of First Refusal in full (or to such lesser extent as the Company and the Participant otherwise agree) within the period specified in Section 11.4 above, the Participant may conclude a transfer to the Proposed Transferee of the Transfer Shares on the terms and conditions described in the Transfer Notice, provided such transfer occurs not later than ninety (90) days following delivery to the Company of the Transfer Notice. The Company shall have the right to demand further assurances from the Participant and the Proposed Transferee (in a form satisfactory to the Company) that the transfer of the Transfer Shares was actually carried out on the terms and conditions described in the Transfer Notice. No Transfer Shares shall be transferred on the books of the Company until the Company has received such assurances, if so demanded, and has approved the proposed transfer as bona fide. Any proposed transfer on terms and conditions different from those described in the Transfer Notice, as well as any subsequent proposed transfer by the Participant, shall again be subject to the Right of First Refusal and shall require compliance by the Participant with the procedure described in this Section 11.

11.6 Transferees of Transfer Shares. All transferees of the Transfer Shares or any interest therein, other than the Company, shall be required as a condition of such transfer to agree in writing (in a form satisfactory to the Company) that such transferee shall receive and hold such Transfer Shares or interest therein subject to all of the terms and conditions of this Option Agreement, including this Section 11 providing for the Right of First Refusal with respect to any subsequent transfer. Any sale or transfer of any shares acquired upon exercise of the Option shall be void unless the provisions of this Section 11 are met.

11.7 Transfers Not Subject to Right of First Refusal. The Right of First Refusal shall not apply to any transfer or exchange of the shares acquired upon exercise of the Option if such transfer or exchange is in connection with an Ownership Change Event. If the consideration received pursuant to such transfer or exchange consists of stock of a Participating Company, such consideration shall remain subject to the Right of First Refusal unless the provisions of Section 11.9 below result in a termination of the Right of First Refusal. The Right of First Refusal does not apply to any transfer or exchange of shares governed by the right of first refusal set forth in the Company’s Bylaws.

11.8 Assignment of Right of First Refusal. The Company shall have the right to assign the Right of First Refusal at any time, whether or not there has been an attempted transfer, to one or more persons as may be selected by the Company.

11.9 Early Termination of Right of First Refusal. The other provisions of this Option Agreement notwithstanding, the Right of First Refusal shall terminate and be of no further force and effect upon (a) the occurrence of a Change in Control, unless the Acquiring Corporation assumes the Company’s rights and obligations under the Option or substitutes a substantially equivalent option for the Acquiring Corporation’s stock for the Option, or (b) the existence of a public market for the class of shares subject to the Right of First Refusal. A “public market” shall be deemed to exist if (i) such stock is listed on a national securities exchange (as that term is used in the Exchange Act) or other stock exchange, (ii) such stock is traded on the over-the-counter market and prices therefor are published daily on business days in a recognized financial journal.

12. STOCK DISTRIBUTIONS SUBJECT TO OPTION AGREEMENT.

If, from time to time, there is any stock dividend, stock split or other change, as described in Section 9, in the character or amount of any of the outstanding stock of the corporation the stock of which is subject to the provisions of this Option Agreement, then in such event any and all new, substituted or additional securities to which the Participant is entitled by reason of the Participant’s ownership of the shares acquired upon exercise of the Option shall be immediately subject to the Right of First Refusal with the same force and effect as the shares subject to the Right of First Refusal immediately before such event.

13. NOTICE OF SALES UPON DISQUALIFYING DISPOSITION.

The Participant shall dispose of the shares acquired pursuant to the Option only in accordance with the provisions of this Option Agreement. In addition, if the Notice designates this Option as an Incentive Stock Option, the Participant shall (a) promptly notify the Chief Financial Officer of the Company if the Participant disposes of any of the shares acquired pursuant to the Option within one (1) year after the date the Participant exercises all or part of the

Option or within two (2) years after the Date of Option Grant and (b) provide the Company with a description of the circumstances of such disposition. Until such time as the Participant disposes of such shares in a manner consistent with the provisions of this Option Agreement, unless otherwise expressly authorized by the Company, the Participant shall hold all shares acquired pursuant to the Option in the Participant’s name (and not in the name of any nominee) for the one-year period immediately after the exercise of the Option and the two-year period immediately after Date of Option Grant. At any time during the one-year or two-year periods set forth above, the Company may place a legend on any certificate representing shares acquired pursuant to the Option requesting the transfer agent for the Company’s stock to notify the Company of any such transfers. The obligation of the Participant to notify the Company of any such transfer shall continue notwithstanding that a legend has been placed on the certificate pursuant to the preceding sentence.

14. LEGENDS.

The Company may at any time place legends referencing the Right of First Refusal and any applicable federal, state or foreign securities law restrictions on all certificates representing shares of stock subject to the provisions of this Option Agreement. The Participant shall, at the request of the Company, promptly present to the Company any and all certificates representing shares acquired pursuant to the Option in the possession of the Participant in order to carry out the provisions of this Section. Unless otherwise specified by the Company, legends placed on such certificates may include, but shall not be limited to, the following:

14.1 “THE SECURITIES EVIDENCED BY THIS CERTIFICATE HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, AND MAY NOT BE SOLD, TRANSFERRED, ASSIGNED OR HYPOTHECATED UNLESS THERE IS AN EFFECTIVE REGISTRATION STATEMENT UNDER SUCH ACT COVERING SUCH SECURITIES, THE SALE IS MADE IN ACCORDANCE WITH RULE 144 OR RULE 701 UNDER THE ACT, OR THE COMPANY RECEIVES AN OPINION OF COUNSEL REASONABLY SATISFACTORY TO THE COMPANY, STATING THAT SUCH SALE, TRANSFER, ASSIGNMENT OR HYPOTHECATION IS EXEMPT FROM THE REGISTRATION AND PROSPECTUS DELIVERY REQUIREMENTS OF SUCH ACT.”

14.2 “THE SHARES REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO A RIGHT OF FIRST REFUSAL OPTION IN FAVOR OF THE CORPORATION OR ITS ASSIGNEE SET FORTH IN AN AGREEMENT BETWEEN THE CORPORATION AND THE REGISTERED HOLDER, OR SUCH HOLDER’S PREDECESSOR IN INTEREST, A COPY OF WHICH IS ON FILE AT THE PRINCIPAL OFFICE OF THIS CORPORATION.”

14.3 If the Option is an Incentive Stock Option: “THE SHARES EVIDENCED BY THIS CERTIFICATE WERE ISSUED BY THE CORPORATION TO THE REGISTERED HOLDER UPON EXERCISE OF AN INCENTIVE STOCK OPTION AS DEFINED IN SECTION 422 OF THE INTERNAL REVENUE CODE OF 1986, AS AMENDED (“ISO”). IN ORDER TO OBTAIN THE PREFERENTIAL TAX TREATMENT

AFFORDED TO ISOs, THE SHARES SHOULD NOT BE TRANSFERRED PRIOR TO [INSERT DISQUALIFYING DISPOSITION DATE HERE]. SHOULD THE REGISTERED HOLDER ELECT TO TRANSFER ANY OF THE SHARES PRIOR TO THIS DATE AND FOREGO ISO TAX TREATMENT, THE TRANSFER AGENT FOR THE SHARES SHALL NOTIFY THE CORPORATION IMMEDIATELY. THE REGISTERED HOLDER SHALL HOLD ALL SHARES PURCHASED UNDER THE INCENTIVE STOCK OPTION IN THE REGISTERED HOLDER’S NAME (AND NOT IN THE NAME OF ANY NOMINEE) PRIOR TO THIS DATE OR UNTIL TRANSFERRED AS DESCRIBED ABOVE.”

15. LOCK-UP AGREEMENT.

The Participant hereby agrees that in the event of any underwritten public offering of stock, including an initial public offering of stock, made by the Company pursuant to an effective registration statement filed under the Securities Act or comparable process under the laws of another jurisdiction, the Participant shall not offer, sell, contract to sell, pledge, hypothecate, grant any option to purchase or make any short sale of, or otherwise dispose of any shares of stock of the Company or any rights to acquire stock of the Company for such period of time from and after the effective date of such registration statement or offering as may be established by the underwriter for such public offering; provided, however, that such period of time shall not exceed one hundred eighty (180) days from the effective date of the registration statement to be filed in connection with such public offering. The foregoing limitation shall not apply to shares registered in the public offering under the Securities Act.

16. RESTRICTIONS ON TRANSFER OF SHARES.

No shares acquired upon exercise of the Option may be sold, exchanged, transferred (including, without limitation, any transfer to a nominee or agent of the Participant), assigned, pledged, hypothecated or otherwise disposed of, including by operation of law, in any manner which violates any of the provisions of this Option Agreement and any such attempted disposition shall be void. The Company shall not be required (a) to transfer on its books any shares which will have been transferred in violation of any of the provisions set forth in this Option Agreement or (b) to treat as owner of such shares or to accord the right to vote as such owner or to pay dividends to any transferee to whom such shares will have been so transferred.

17. MISCELLANEOUS PROVISIONS.

17.1 Binding Effect. Subject to the restrictions on transfer set forth herein, this Option Agreement shall inure to the benefit of and be binding upon the parties hereto and their respective heirs, executors, administrators, successors and assigns.

17.2 Termination or Amendment. The Board may terminate or amend the Plan or the Option at any time; provided, however, that except as provided in Section 8 in connection with a Change in Control, no such termination or amendment may adversely affect the Option or any unexercised portion hereof without the consent of the Participant unless such termination or amendment is necessary to comply with any applicable law or government regulation or is required to enable the Option, if designated an Incentive Stock Option in the Notice, to qualify as an Incentive Stock Option. No amendment or addition to this Option Agreement shall be effective unless in writing.

17.3 Notices. Any notice required or permitted hereunder shall be given in writing and shall be deemed effectively given (except to the extent that this Option Agreement provides for effectiveness only upon actual receipt of such notice) upon personal delivery or upon deposit in the United States Post Office, by registered or certified mail, with postage and fees prepaid, addressed to the other party at the address shown below that party’s signature on the Notice or at such other address as such party may designate in writing from time to time to the other party.

17.4 Integrated Agreement. The Notice, this Option Agreement and the Plan constitute the entire understanding and agreement of the Participant and the Participating Company Group with respect to the subject matter contained herein or therein and supersedes any prior agreements, understandings, restrictions, representations, or warranties among the Participant and the Participating Company Group with respect to such subject matter other than those as set forth or provided for herein or therein. To the extent contemplated herein or therein, the provisions of the Notice and the Option Agreement shall survive any exercise of the Option and shall remain in full force and effect.

17.5 Applicable Law. This Option Agreement shall be governed by the laws of the State of California as such laws are applied to agreements between California residents entered into and to be performed entirely within the State of California.

17.6 Counterparts. The Notice may be executed in counterparts, each of which shall be deemed an original, but all of which together shall constitute one and the same instrument.

Incentive Stock Option

Participant:

Nonstatutory Stock Option

Date:

STOCK OPTION EXERCISE NOTICE

IGM Biosciences, Inc.

Attention: Secretary

325 E. Middlefield Rd.

Mountain View, CA 94043

Ladies and Gentlemen:

1. Option. I was granted an option (the “Option”) to purchase shares of the common stock (the “Shares”) of IGM Biosciences, Inc. (the “Company”) pursuant to the Company’s 2010 Stock Plan (the “Plan”), my Notice of Grant of Stock Option (the “Notice”) and my Stock Option Agreement (the “Option Agreement”) as follows:

2. Exercise of Option. I hereby elect to exercise the Option to purchase the following number of Shares, all of which are Vested Shares in accordance with the Notice and the Option Agreement:

3. Payments. I enclose payment in full of the total exercise price for the Shares in the following form(s), as authorized by my Option Agreement:

4. Tax Withholding. I authorize payroll withholding and otherwise will make adequate provision for the federal, state, local and foreign tax withholding obligations of the Company, if any, in connection with the Option. If I am exercising a Nonstatutory Stock Option, I enclose payment in full of my withholding taxes, if any, as follows:

(Contact Plan Administrator for amount of tax due.)

5. Participant Information.


My address is:



My Social Security Number is:

6. Notice of Disqualifying Disposition. If the Option is an Incentive Stock Option, I agree that I will promptly notify the Chief Financial Officer of the Company if I transfer any of the Shares within one (1) year from the date I exercise all or part of the Option or within two (2) years of the Date of Option Grant.

7. Binding Effect. I agree that the Shares are being acquired in accordance with and subject to the terms, provisions and conditions of the Option Agreement, including the Right of First Refusal set forth therein, to all of which I hereby expressly assent. This Agreement shall inure to the benefit of and be binding upon my heirs, executors, administrators, successors and assigns.

8. Transfer. I understand and acknowledge that the Shares have not been registered under the Securities Act of 1933, as amended (the “Securities Act”), and that consequently the Shares must be held indefinitely unless they are subsequently registered under the Securities Act, an exemption from such registration is available, or they are sold in accordance with Rule 144 or Rule 701 under the Securities Act. I further understand and acknowledge that the Company is under no obligation to register the Shares. I understand that any certificate or certificates evidencing the Shares will be imprinted with legends which prohibit the transfer of the Shares unless they are registered or such registration is not required in the opinion of legal counsel satisfactory to the Company.

I am aware that Rule 144 under the Securities Act, which permits limited public resale of securities acquired in a nonpublic offering, is not currently available with respect to the Shares and, in any event, is available only if certain conditions are satisfied. I understand that any sale of the Shares that might be made in reliance upon Rule 144 may only be made in limited amounts in accordance with the terms and conditions of such rule and that a copy of Rule 144 will be delivered to me upon request.

I understand that I am purchasing the Shares pursuant to the terms of the Plan, the Notice and my Option Agreement, copies of which I have received and carefully read and understand.

Very truly yours,

(Signature)

Receipt of the above is hereby acknowledged.

IGM BIOSCIENCES, INC.



By:



Title:



Dated::