TOCAGEN INC. WARRANT TOPURCHASE COMMON STOCK

Exhibit 4.2

THIS WARRANT AND THE UNDERLYING SECURITIES HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “ACT”). THEY MAY NOT BE SOLD, OFFERED FOR SALE, PLEDGED OR HYPOTHECATED IN THE ABSENCE OF AN EFFECTIVE REGISTRATION STATEMENT AS TO SUCH SECURITIES UNDER THE ACT OR AN OPINION OF COUNSEL SATISFACTORY TO THE COMPANY THAT SUCH REGISTRATION IS NOT REQUIRED.

TOCAGEN INC.

WARRANT TO PURCHASE COMMON STOCK

VOID AFTER JUNE 4TH, 2023

THIS CERTIFIES THAT, for value received, Voices Against Brain Cancer (the “Holder”), is entitled to subscribe for and purchase from TOCAGEN INC., a Delaware corporation (the “Company”), 5,000 Exercise Shares at the Exercise Price (each subject to adjustment as provided herein). This Warrant is issued to Holder in connection with that certain Consulting Agreement, dated on even date herewith, by and between Holder and the Company (as the same may be amended from time to time, the “Consulting Agreement”).

1. DEFINITIONS. As used herein, the following terms shall have the following respective meanings:

(a) “Change in Control” means (a) a sale of all or substantially all of the assets of the Company; (b) a merger or consolidation in which the Company is not the surviving corporation (other than a merger or consolidation in which stockholders immediately before the merger or consolidation have, immediately after the merger or consolidation, a majority of the voting power of the surviving corporation); (c) a reverse merger in which the Company is the surviving corporation but the shares of the Company’s Common Stock outstanding immediately preceding the merger are converted by virtue of the merger into other property, whether in the form of securities, cash or otherwise (other than a reverse merger in which stockholders immediately before the merger have, immediately after the merger, a majority of the voting power of the surviving corporation); or (d) any transaction or series of related transactions in which in excess of 50% of the Company’s voting power is transferred, other than the sale by the Company of stock in transactions the primary purpose of which is to raise capital for the Company’s operations and activities.

(b) “Exercise Period” shall mean the period commencing with the date hereof and ending ten (10) years later, unless sooner terminated as provided below.

(c) “Exercise Price” shall mean $0.57 per Exercise Share subject to adjustment pursuant to Section 5 below.

(d) “Exercise Shares” shall mean shares of the Company’s Common Stock issuable upon exercise of this Warrant.

(e) “Services” shall have the meaning ascribed to it in the Consulting Agreement.

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2. VESTING SCHEDULE AND EXERCISE OF WARRANT.

2.1 Vesting Schedule. One fourth (1/4^th) of the Exercise Shares shall vest and be eligible for purchase on the one- (1) year anniversary of the date hereof and one forty-eighth (1/48^th) of the Exercise Shares shall vest and be eligible for purchase monthly thereafter until all of the Exercise Shares have vested, provided that Holder continues to provide Services to the Company. In addition, one fourth (1/4^th) of the Exercise Shares (or all remaining unvested Exercise Shares, if less) shall vest and be eligible for purchase immediately prior to the effective time of a Change of Control. Upon expiration or termination of the Consulting Agreement, vesting of the Exercise Shares shall cease and this Warrant shall thereafter remain exercisable for up to that number of Exercise Shares as were vested as of the effective time of such expiration or termination.

2.2 Exercise of Warrant. The rights represented by this Warrant may be exercised in whole or in part at any time during the Exercise Period so long as the Exercise Shares for which this Warrant is being exercised are then vested and exercisable hereunder in accordance with Section 2.1, by delivery of the following to the Company at its address set forth above (or at such other address as it may designate by notice in writing to the Holder):

(a) An executed Notice of Exercise in the form attached hereto, which includes an agreement to become a party to the Voting Agreement (defined in the form of Notice of Exercise);

(b) Payment of the Exercise Price either in cash or by check; and

(c) This Warrant.

Upon the exercise of the rights represented by this Warrant, a certificate or certificates for the Exercise Shares so purchased, registered in the name of the Holder or persons affiliated with the Holder, if the Holder so designates, shall be issued and delivered to the Holder within a reasonable time after the rights represented by this Warrant shall have been so exercised. In the event that this Warrant is being exercised for less than all of the then-current number of Exercise Shares purchasable hereunder, the Company shall, concurrently with the issuance by the Company of the number of Exercise Shares for which this Warrant is then being exercised, issue a new Warrant exercisable for the remaining number of Exercise Shares purchasable hereunder.

The person in whose name any certificate or certificates for Exercise Shares are to be issued upon exercise of this Warrant shall be deemed to have become the holder of record of such shares on the date on which this Warrant was surrendered and payment of the Exercise Price was made, irrespective of the date of delivery of such certificate or certificates, except that, if the date of such surrender and payment is a date when the stock transfer books of the Company are closed, such person shall be deemed to have become the holder of such shares at the close of business on the next succeeding date on which the stock transfer books are open.

2.3 Net Exercise. Notwithstanding any provisions herein to the contrary, if the fair market value of one Exercise Share is greater than the Exercise Price (at the date of calculation as set forth below), in lieu of exercising this Warrant by payment of cash, the Holder may elect to receive shares equal to the value (as determined below) of this Warrant (or the

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portion thereof being canceled) by surrender of this Warrant at the principal office of the Company together with the properly endorsed Notice of Exercise (but solely with respect to Exercise Shares that are then vested and exercisable hereunder in accordance with Section 2.1) in which event the Company shall issue to the Holder a number of Exercise Shares computed using the following formula:

For purposes of the above calculation, the fair market value of one Exercise Share shall be determined by the Company’s Board of Directors in good faith; provided, however, that in the event that this Warrant is exercised pursuant to this Section 2.3 in connection with the Company’s initial public offering of its Common Stock, the fair market value per share shall be the per share offering price to the public of the Company’s initial public offering.

3. COVENANTS OF THE COMPANY AS TO EXERCISE SHARES. The Company covenants and agrees that all Exercise Shares that may be issued upon the exercise of the rights represented by this Warrant will, upon issuance, be validly issued and outstanding, fully paid and nonassessable, and free from all taxes, liens and charges with respect to the issuance thereof. The Company further covenants and agrees that the Company will at all times during the Exercise Period, have authorized and reserved, free from preemptive rights, a sufficient number of shares of the series of equity securities comprising the Exercise Shares to provide for the exercise of the rights represented by this Warrant. If at any time during the Exercise Period the number of authorized but unissued shares of such series of the Company’s equity securities shall not be sufficient to permit exercise of this Warrant, the Company will take such corporate action as may, in the opinion of its counsel, be necessary to increase its authorized but unissued shares of such series of the Company’s equity securities to such number of shares as shall be sufficient for such purposes.

4. REPRESENTATIONS OF HOLDER.

4.1 Acquisition of Warrant for Personal Account. The Holder represents and warrants that it is acquiring the Warrant and the Exercise Shares solely for its account for investment and not with a view to or for sale or distribution of said Warrant or Exercise Shares or any part thereof. The Holder also represents that the entire legal and beneficial interests of the Warrant and Exercise Shares the Holder is acquiring is being acquired for, and will be held for, its account only.

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4.2 Information and Sophistication. Holder hereby: (i) acknowledges that it has received all the information it has requested from the Company and it considers necessary or appropriate for deciding whether to acquire this Warrant and the Exercise Shares, (ii) represents that it has had an opportunity to ask questions and receive answers from the Company regarding the financial condition of the Company and the risks associated with the acquisition of this Warrant and the Exercise Shares and (iii) further represents that it has such knowledge and experience in financial and business matters that it is capable of evaluating the merits and risk of this investment.

4.3 Ability to Bear Economic Risk. Holder acknowledges that investment in the securities of the Company involves a high degree of risk, and represents that it is able, without materially impairing its financial condition, to hold the Exercise Shares for an indefinite period of time and to suffer a complete loss of its investment.

4.4 Securities Are Not Registered.

(a) The Holder understands that the Warrant and the Exercise Shares have not been registered under the Securities Act of 1933, as amended (the “Act”) on the basis that no distribution or public offering of the stock of the Company is to be effected. The Holder realizes that the basis for the exemption may not be present if, notwithstanding its representations, the Holder has a present intention of acquiring the securities for a fixed or determinable period in the future, selling (in connection with a distribution or otherwise), granting any participation in, or otherwise distributing the securities. The Holder has no such present intention.

(b) The Holder recognizes that the Warrant and the Exercise Shares must be held indefinitely unless they are subsequently registered under the Act or an exemption from such registration is available. The Holder recognizes that the Company has no obligation to register the Warrant or the Exercise Shares of the Company, or to comply with any exemption from such registration.

(c) The Holder is aware that neither the Warrant nor the Exercise Shares may be sold pursuant to Rule 144 adopted under the Act unless certain conditions are met, including, among other things, the existence of a public market for the shares, the availability of certain current public information about the Company, the resale following the required holding period under Rule 144 and the number of shares being sold during any three month period not exceeding specified limitations. Holder is aware that the conditions for resale set forth in Rule 144 have not been satisfied and that the Company presently has no plans to satisfy these conditions in the foreseeable future.

4.5 Disposition of Warrant and Exercise Shares.

(a) The Holder further agrees not to make any disposition of all or any part of the Warrant or Exercise Shares in any event unless and until:

(i) The Company shall have received a letter secured by the Holder from the Securities and Exchange Commission stating that no action will be recommended to the Commission with respect to the proposed disposition;

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(ii) There is then in effect a registration statement under the Act covering such proposed disposition and such disposition is made in accordance with said registration statement; or

(iii) The Holder shall have notified the Company of the proposed disposition and shall have furnished the Company with a detailed statement of the circumstances surrounding the proposed disposition, and if reasonably requested by the Company, the Holder shall have furnished the Company with an opinion of counsel, reasonably satisfactory to the Company, for the Holder to the effect that such disposition will not require registration of such Warrant or Exercise Shares under the Act or any applicable state securities laws. The Company agrees that it will not require an opinion of counsel with respect to transactions under Rule 144 of the Act, except in unusual circumstances.

(b) The Holder understands and agrees that all certificates evidencing the shares to be issued to the Holder may bear the following legend:

THESE SECURITIES HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “ACT”). THEY MAY NOT BE SOLD, OFFERED FOR SALE, PLEDGED OR HYPOTHECATED IN THE ABSENCE OF AN EFFECTIVE REGISTRATION STATEMENT AS TO THE SECURITIES UNDER THE ACT OR AN OPINION OF COUNSEL SATISFACTORY TO THE COMPANY THAT SUCH REGISTRATION IS NOT REQUIRED.

4.6 Accredited Investor Status. The Holder has the business and financial experience to protect its own interests in connection with acquisition of this Warrant and the Exercise Shares.

5. ADJUSTMENT OF EXERCISE PRICE AND NUMBER OF EXERCISE SHARES. In the event of changes in the series of equity securities of the Company comprising the Exercise Shares by reason of stock dividends, splits, recapitalizations, reclassifications, combinations or exchanges of shares, separations, reorganizations, liquidations, or the like, the number and class of Exercise Shares available under the Warrant in the aggregate and the Exercise Price shall be correspondingly adjusted to give the Holder of the Warrant, on exercise for the same aggregate Exercise Price, the total number, class, and kind of shares as the Holder would have owned had the Warrant been exercised prior to the event and had the Holder continued to hold such shares until after the event requiring adjustment; provided, however, that such adjustment shall not be made with respect to, and this Warrant shall terminate if not exercised prior to, the events set forth in Section 7 below. For purposes of this Section 5, the “aggregate Exercise Price” shall mean the aggregate Exercise Price payable in connection with the exercise in full of this Warrant. The form of this Warrant need not be changed because of any adjustment in the number of Exercise Shares subject to this Warrant.

6. FRACTIONAL SHARES. No fractional shares shall be issued upon the exercise of this Warrant as a consequence of any adjustment pursuant hereto. All Exercise Shares (including fractions) to be issued upon exercise of this Warrant shall be aggregated for purposes of determining whether the exercise would result in the issuance of any fractional share. If, after

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aggregation, the exercise would result in the issuance of a fractional share, the Company shall, in lieu of issuance of any fractional share, pay the Holder otherwise entitled to such fraction a sum in cash equal to the product resulting from multiplying the then current fair market value of one Exercise Share by such fraction.

7. EARLY TERMINATION.

7.1 Change in Control. In the event of, at any time during the Exercise Period, a Change in Control, the Company shall provide to the Holder ten (10) days advance written notice of such Change in Control, and this Warrant shall terminate unless exercised immediately prior to the effective time of such Change in Control.

7.2 Termination of Consulting Agreement. In the event that the Consulting Agreement expires or is terminated at any time during the Exercise Period, this Warrant shall terminate on the ninetieth (90^th) day after the date of such expiration or termination unless exercised prior to such termination.

8. MARKET STAND-OFF AGREEMENT. Holder shall not sell, dispose of, transfer, make any short sale of, grant any option for the purchase of, or enter into any hedging or similar transaction with the same economic effect as a sale, any Common Stock (or other securities) of the Company held by Holder, for a period of one hundred eighty (180) days following the effective date of a registration statement of the Company filed under the Act (the “Lock-Up Period”) (or such longer period, not to exceed thirty-four (34) days after the expiration of the 180-day period, as the underwriters or the Company shall request in order to facilitate compliance with NASD Rule 2711). Holder agrees to execute and deliver such other agreements as may be reasonably requested by the Company and/or the managing underwriter which are consistent with the foregoing or which are necessary to give further effect thereto. In order to enforce the foregoing covenant, the Company may impose stop-transfer instructions with respect to such Common Stock (or other securities) until the end of such period. The underwriters of the Company’s stock are intended third party beneficiaries of this Section 8 and shall have the right, power and authority to enforce the provisions hereof as though they were a party hereto. For the avoidance of doubt, if Holder sells any Common Stock either (a) on the open market after the Company’s initial public offering under an effective registration statement filed under the Act or (b) pursuant to Rule 144 under the Act, then, provided such sale otherwise complies with the terms of this Warrant, the shares of Common Stock so sold by Holder shall cease to be subject to the provisions of this Section 8.

9. NO STOCKHOLDER RIGHTS. This Warrant in and of itself shall not entitle the Holder to any voting rights or other rights as a stockholder of the Company.

10. TRANSFER OF WARRANT. Subject to applicable laws and the restriction on transfer set forth on the first page and Section 4.5 of this Warrant, this Warrant and all rights hereunder are transferable, by the Holder in person or by duly authorized attorney, upon delivery of this Warrant and the form of assignment attached hereto to any transferee designated by Holder. The transferee shall sign an investment letter in form and substance satisfactory to the Company.

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11. LOST, STOLEN, MUTILATED OR DESTROYED WARRANT. If this Warrant is lost, stolen, mutilated or destroyed, the Company may, on such terms as to indemnity or otherwise as it may reasonably impose (which shall, in the case of a mutilated Warrant, include the surrender thereof), issue a new Warrant of like denomination and tenor as the Warrant so lost, stolen, mutilated or destroyed. Any such new Warrant shall constitute an original contractual obligation of the Company, whether or not the allegedly lost, stolen, mutilated or destroyed Warrant shall be at any time enforceable by anyone.

12. AMENDMENT. Any term of this Warrant may be amended or waived with the written consent of the Company and Holder.

13. NOTICES, ETC. All notices required or permitted hereunder shall be in writing and shall be deemed effectively given: (a) upon personal delivery to the party to be notified, (b) when sent by confirmed telex or facsimile if sent during normal business hours of the recipient, if not, then on the next business day, (c) five days after having been sent by registered or certified mail, return receipt requested, postage prepaid, or (d) one day after deposit with a nationally recognized overnight courier, specifying next day delivery, with written verification of receipt. All communications shall be sent to the Company at the address listed below and to Holder at the address provided to the Company or such other address as the Company or Holder may designate by 10 days advance written notice to the other parties hereto.

14. ACCEPTANCE. Receipt of this Warrant by the Holder shall constitute acceptance of and agreement to all of the terms and conditions contained herein.

15. GOVERNING LAW. This Warrant and all rights, obligations and liabilities hereunder shall be governed by and construed under the laws of the State of California as applied to agreements among California residents, made and to be performed entirely within the State of California without giving effect to conflicts of laws principles.

IN WITNESS WHEREOF, the Company has caused this Warrant to be executed by its duly authorized officer as of June 5th, 2013.

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NOTICE OF EXERCISE

TO: TOCAGEN INC.

(1) ☐ The undersigned hereby elects to purchase ________ shares of Common Stock (the “Exercise Shares”) of Tocagen Inc. (the “Company”) pursuant to the terms of the attached Warrant, and tenders herewith payment of the exercise price in full, together with all applicable transfer taxes, if any.

☐ The undersigned hereby elects to purchase ________ shares of Common Stock (the “Exercise Shares”) of Tocagen Inc. (the “Company”) pursuant to the terms of the net exercise provisions set forth in Section 2.3 of the attached Warrant, and shall tender payment of all applicable transfer taxes, if any.

(2) Please issue a certificate or certificates representing said Exercise Shares in the name of the undersigned or in such other name as is specified below:

______________________________

(Name)

______________________________

______________________________

(Address)

(3) The undersigned and the Company hereby agree that the undersigned is a party to that certain Voting Agreement, dated December 20, 2007, between certain holders of Common Stock of the Company (the “Voting Agreement”) pursuant to which such holders of Common Stock grant to Harry Gruber, M.D. the power and authority to vote all shares of Common Stock represented by the Voting Agreement on all matters for which a vote of holders of Common Stock of the Company is required or requested as set forth in the Voting Agreement. The undersigned also agrees that, upon request, it will deliver to the Company a counterpart signature page to the Voting Agreement, duly executed by the Holder. The undersigned represents and agrees that it has had the opportunity to review and to seek the advise of legal counsel with respect to the Voting Agreement.

(4) The undersigned represents that (i) the aforesaid Exercise Shares are being acquired for the account of the undersigned for investment and not with a view to, or for resale in connection with, the distribution thereof and that the undersigned has no present intention of distributing or reselling such shares; (ii) the undersigned is aware of the Company’s business affairs and financial condition and has acquired sufficient information about the Company to reach an informed and knowledgeable decision regarding its investment in the Company; (iii) the undersigned is experienced in making investments of this type and has such knowledge and background in financial and business matters that the undersigned is capable of evaluating the merits and risks of this investment and protecting the undersigned’s own interests; (iv) the undersigned understands that Exercise Shares issuable upon exercise of this Warrant have not been registered under the Securities Act of 1933, as amended (the “Act”), by reason of a specific exemption from the registration provisions of the Act, which exemption depends upon, among other things, the bona fide nature of the investment intent as expressed herein, and, because such securities have not been registered under the Act, they must be held indefinitely unless

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subsequently registered under the Act or an exemption from such registration is available; (v) the undersigned is aware that the aforesaid Exercise Shares may not be sold pursuant to Rule 144 adopted under the Act unless certain conditions are met and until the undersigned has held the shares for the number of years prescribed by Rule 144, that among the conditions for use of the Rule is the availability of current information to the public about the Company and the Company has not made such information available and has no present plans to do so; and (vi) the undersigned agrees not to make any disposition of all or any part of the aforesaid shares of Exercise Shares unless and until there is then in effect a registration statement under the Act covering such proposed disposition and such disposition is made in accordance with said registration statement, or, if reasonably requested by the Company, the undersigned has provided the Company with an opinion of counsel satisfactory to the Company, stating that such registration is not required.

(5) No Exercise Shares subject to the attached Warrant may be exercised prior to the vesting of such Exercise Shares in accordance with Section 2 of such Warrant.

Signature of such person or entity listed in (2) above, if different than Holder:

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ASSIGNMENT FORM

(To assign the foregoing Warrant, execute this form and supply required information. Do not use this form to purchase shares.)

FOR VALUE RECEIVED, the foregoing Warrant and all rights evidenced thereby are hereby assigned to

Dated:                     , 20    

NOTE: The signature to this Assignment Form must correspond with the name as it appears on the face of the Warrant, without alteration or enlargement or any change whatever. Officers of corporations and those acting in a fiduciary or other representative capacity should file proper evidence of authority to assign the foregoing Warrant.

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