EX-4.3




 Exhibit 4.3 

FOR PURPOSES OF SECTION 1272, 1273 AND 1275 OF THE INTERNAL REVENUE CODE OF 1986, AS AMENDED, THIS NOTE IS BEING ISSUED WITH AN ORIGINAL ISSUE DISCOUNT. THE
COMPANY AGREES TO PROVIDE PROMPTLY TO THE HOLDER OF THIS NOTE, UPON WRITTEN REQUEST, THE ISSUE PRICE, AMOUNT OF ORIGINAL ISSUE DISCOUNT, ISSUE DATE AND YIELD TO MATURITY. ANY SUCH WRITTEN REQUEST SHOULD BE MADE TO THE ATTENTION OF THE CHIEF
OPERATING OFFICER OF THE COMPANY WITH A COPY (WHICH SHALL NOT CONSTITUTE NOTICE) TO HERBERT FOCKLER, WILSON SONSINI GOODRICH & ROSATI, P.C., 650 PAGE MILL ROAD, PALO ALTO, CA 94304. 

THIS WARRANT AND THE UNDERLYING SECURITIES HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “ACT”), OR UNDER
THE SECURITIES LAWS OF ANY STATE. THESE SECURITIES MAY NOT BE OFFERED, SOLD OR OTHERWISE TRANSFERRED, PLEDGED OR HYPOTHECATED EXCEPT AS PERMITTED UNDER THE ACT AND APPLICABLE STATE SECURITIES LAWS IN ACCORDANCE WITH APPLICABLE REGISTRATION
REQUIREMENTS OR AN EXEMPTION THEREFROM. THE ISSUER OF THESE SECURITIES MAY REQUIRE AN OPINION OF COUNSEL REASONABLY SATISFACTORY TO THE ISSUER THAT SUCH OFFER, SALE, TRANSFER, PLEDGE OR HYPOTHECATION OTHERWISE COMPLIES WITH THE ACT AND ANY
APPLICABLE STATE SECURITIES LAWS. THIS WARRANT MUST BE SURRENDERED TO THE COMPANY OR ITS TRANSFER AGENT AS A CONDITION PRECEDENT TO THE SALE, TRANSFER, PLEDGE OR HYPOTHECATION OF ANY INTEREST IN ANY OF THE SECURITIES REPRESENTED HEREBY. 

WARRANT TO PURCHASE SHARES OF COMMON STOCK 

of 
 MULTIVIR, INC.

 Dated as of [date] 

Void after the date specified in Section 7 
  

			
	No. [            ]	 	 Warrant to Purchase

Shares of Common Stock


 THIS CERTIFIES THAT, for value received, Pope Investments II LLC, or its registered assigns (the
“Holder”), is entitled, subject to the provisions and upon the terms and conditions set forth herein, to purchase from MultiVir, Inc., a Delaware corporation (the “Company”),
[                ] Shares (as defined below), at such times and at the price per share set forth in Section 1 prior to (or in connection with) the expiration of
this Warrant, as provided in Section 7. The term “Warrant” as used herein shall include this Warrant and any warrants delivered in substitution or exchange therefor as provided herein. This Warrant is issued in
connection with the transactions described in the Credit Facility Agreement, dated effective as of December 4, 2014, by and among the Company and the purchasers described therein (the “Credit Facility Agreement”). The holder
of this Warrant is subject to certain restrictions set forth in the Credit Facility Agreement. 








 The following is a statement of the rights of the Holder and the conditions to which this Warrant
is subject, and to which Holder, by acceptance of this Warrant, agrees: 
 1. Number and Price of Shares; Exercise Period. 

(a) Definition of Shares. “Shares” shall mean shares of the Common Stock of the Company, par value
$0.001 per share. 
 (b) Exercise Price. The exercise price per Share shall be equal to $12.50 per share of Common Stock. 

(c) Exercise Period. This Warrant shall be exercisable, in whole or in part, at the election by the all the Lenders prior to (or
in connection with) the expiration of this Warrant as set forth in Section 7. 
 2. Exercise of the Warrant. 

(a) Exercise. The purchase rights represented by this Warrant may be exercised at the election of the Holder, in whole or in
part, by: 
 (i) the tender to the Company at its principal office (or such other office or agency as the Company may designate) of a
notice of exercise in the form of Exhibit A (the “Notice of Exercise”), duly completed and executed by or on behalf of the Holder, together with the surrender of this Warrant; and 

(ii) the payment to the Company of an amount equal to (x) the Exercise Price multiplied by (y) the number of Shares being
purchased, by (a) wire transfer or certified, cashier’s or other check acceptable to the Company and payable to the order of the Company; (b) surrender and cancellation of promissory notes or other instruments representing
indebtedness of the Company to the Holder; or (c) a combination of (a) and (b). 
 (b) Net Issue Exercise. In lieu
of exercising this Warrant pursuant to Section 2(a)(ii), if the fair market value of one Share is greater than the Exercise Price (at the date of calculation as set forth below), the Holder may elect to receive a number of Shares equal to the
value of this Warrant (or of any portion of this Warrant being canceled) by surrender of this Warrant at the principal office of the Company (or such other office or agency as the Company may designate) together with a properly completed and
executed Notice of Exercise reflecting such election, in which event the Company shall issue to the Holder that number of Shares computed using the following formula: 
  

									
	X	  	 	=	  	 	        Y (A – B)        	 	
	  	 	A	 	

 Where: 
  

					
	X	  	=	  	The number of Shares to be issued to the Holder
			
	Y	  	=	  	The number of Shares purchasable under this Warrant or, if only a portion of the Warrant is being exercised, the portion of the Warrant being canceled (at the date of such calculation)
			
	A	  	=	  	The fair market value of one Share (at the date of such calculation)
			
	B	  	=	  	The Exercise Price (as adjusted to the date of such calculation)


  
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 For purposes of the calculation above, the fair market value of one Share shall be determined by the Board of
Directors of the Company, acting in good faith; provided, however, that: 
 (i) where a public market exists for the Company’s
common stock at the time of such exercise, the fair market value per Share shall be the product of (x) the average of the closing bid prices of the common stock or the closing price quoted on the national securities exchange on which the common
stock is listed as published in the Wall Street Journal, as applicable, for the ten (10) trading day period ending five (5) trading days prior to the date of determination of fair market value and (y) the number of shares of
common stock into which each Share is convertible at the time of such exercise, as applicable; and 
 (ii) if the Warrant is exercised in
connection with the Company’s closing of a firm commitment underwritten initial public offering pursuant to an effective registration statement filed under the Securities Act covering the offering and sale of the Company’s common stock
(“Initial Public Offering”), the fair market value per Share shall be the per share offering price to the public of the Company’s Initial Public Offering. 

(c) Change of Control Deemed Cashless Exercise. In the event of a Change of Control (as defined in Section 7), the Warrant
shall be deemed exercised, without any action by the Holder, such exercise to be made on a net exercise basis pursuant to Section 2(b) and to be effective as of the date immediately prior to the consummation of the Change of Control. 

(d) Stock Certificates. The rights under this Warrant shall be deemed to have been exercised and the Shares issuable upon such
exercise shall be deemed to have been issued immediately prior to the close of business on the date this Warrant is exercised in accordance with its terms, and the person entitled to receive the Shares issuable upon such exercise shall be treated
for all purposes as the holder of record of such Shares as of the close of business on such date. As promptly as reasonably practicable on or after such date, the Company shall issue and deliver to the person or persons entitled to receive the same
a certificate or certificates for that number of shares issuable upon such exercise. In the event that the rights under this Warrant are exercised in part and have not expired, the Company shall execute and deliver a new Warrant reflecting the
number of Shares that remain subject to this Warrant. 
 (e) No Fractional Shares or Scrip. No fractional shares or scrip
representing fractional shares shall be issued upon the exercise of the rights under this Warrant. In lieu of such fractional share to which the Holder would otherwise be entitled, the Company shall make a cash payment equal to the Exercise Price
multiplied by such fraction. 
 (f) Conditional Exercise. The Holder may exercise this Warrant conditioned upon (and effective
immediately prior to) consummation of any transaction that would cause the expiration of this Warrant pursuant to Section 7 by so indicating in the notice of exercise. 

(g) Reservation of Stock. The Company agrees during the term the rights under this Warrant are exercisable to reserve and keep
available from its authorized and unissued shares of Common Stock for the purpose of effecting the exercise of this Warrant such number of shares (and shares of common stock for issuance on conversion of such shares) as shall from time to time be
sufficient to effect the exercise of the rights under this Warrant; and if at any time the number of authorized but unissued shares of Common Stock (and shares of common stock for issuance on conversion of such shares) shall not be sufficient for
purposes of the exercise of this Warrant in accordance with its terms and the conversion of the Shares, without limitation of such other remedies as may be available to the Holder, the Company will use all reasonable efforts to take such corporate
action as may, in the opinion of counsel, be necessary to increase its authorized and unissued shares of its Common Stock (and shares of common stock for issuance on conversion of such shares) to a number of shares as shall be sufficient for such
purposes. 

  
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 3. Replacement of the Warrant. Subject to the receipt of evidence reasonably satisfactory
to the Company of the loss, theft, destruction or mutilation of this Warrant and, in the case of loss, theft or destruction, on delivery of an indemnity agreement reasonably satisfactory in form and substance to the Company or, in the case of
mutilation, on surrender and cancellation of this Warrant, the Company at the expense of the Holder shall execute and deliver, in lieu of this Warrant, a new warrant of like tenor and amount. 

4. Transfer of the Warrant. 

(a) Warrant Register. The Company shall maintain a register (the “Warrant Register”) containing the name
and address of the Holder or Holders. Until this Warrant is transferred on the Warrant Register in accordance herewith, the Company may treat the Holder as shown on the Warrant Register as the absolute owner of this Warrant for all purposes,
notwithstanding any notice to the contrary. Any Holder of this Warrant (or of any portion of this Warrant) may change its address as shown on the Warrant Register by written notice to the Company requesting a change. 

(b) Warrant Agent. The Company may appoint an agent for the purpose of maintaining the Warrant Register referred to in
Section 4(a), issuing the Shares or other securities then issuable upon the exercise of the rights under this Warrant, exchanging this Warrant, replacing this Warrant or conducting related activities. 

(c) Transferability of the Warrant. Subject to the provisions of this Warrant with respect to compliance with the Securities Act
of 1933, as amended (the “Securities Act”) and limitations on assignments and transfers, including without limitation compliance with the restrictions on transfer set forth in Section 5, title to this Warrant may be
transferred by endorsement (by the transferor and the transferee executing the assignment form attached as Exhibit B (the “Assignment Form”)) and delivery in the same manner as a negotiable instrument transferable by
endorsement and delivery. 
 (d) Exchange of the Warrant upon a Transfer. On surrender of this Warrant (and a properly
endorsed Assignment Form) for exchange, subject to the provisions of this Warrant with respect to compliance with the Securities Act and limitations on assignments and transfers, the Company shall issue to or on the order of the Holder a new warrant
or warrants of like tenor, in the name of the Holder or as the Holder (on payment by the Holder of any applicable transfer taxes) may direct, for the number of shares issuable upon exercise hereof, and the Company shall register any such transfer
upon the Warrant Register. This Warrant (and the securities issuable upon exercise of the rights under this Warrant) must be surrendered to the Company or its warrant or transfer agent, as applicable, as a condition precedent to the sale, pledge,
hypothecation or other transfer of any interest in any of the securities represented hereby. 
 (e) Taxes. In no event shall
the Company be required to pay any tax which may be payable in respect of any transfer involved in the issue and delivery of any certificate in a name other than that of the Holder, and the Company shall not be required to issue or deliver any such
certificate unless and until the person or persons requesting the issue thereof shall have paid to the Company the amount of such tax or shall have established to the satisfaction of the Company that such tax has been paid or is not payable. 

5. Restrictions on Transfer of the Warrant and Shares; Compliance with Securities Laws. By acceptance of this Warrant, the
Holder agrees to comply with the following: 
 (a) Restrictions on Transfers. Subject to Section 5(b), this
Warrant may not be transferred or assigned in whole or in part without the Company’s prior written consent (which shall not be unreasonably withheld), and any attempt by Holder to transfer or assign any rights, duties or obligations that arise
under this Warrant without such permission shall be void. Any transfer of this Warrant or the Warrant 

  
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Shares (the “Securities”) must be in compliance with all applicable federal and state securities laws. The Holder agrees not to make any sale, assignment, transfer, pledge
or other disposition of all or any portion of the Securities, or any beneficial interest therein, unless and until the transferee thereof has agreed in writing for the benefit of the Company to take and hold such Securities subject to, and to be
bound by, the terms and conditions set forth in this Warrant to the same extent as if the transferee were the original Holder hereunder, and 

(i) there is then in effect a registration statement under the Securities Act covering such proposed disposition and such disposition is made
in accordance with such registration statement, or 
 (ii) (A) such Holder shall have given prior written notice to the Company of
such Holder’s intention to make such disposition and shall have furnished the Company with a detailed description of the manner and circumstances of the proposed disposition, (B) the transferee shall have confirmed to the satisfaction of
the Company in writing, substantially in the form of Exhibit A-1, that the Securities are being acquired (i) solely for the transferee’s own account and not as a nominee for any other party, (ii) for investment and (iii) not
with a view toward distribution or resale, and shall have confirmed such other matters related thereto as may be reasonably requested by the Company, and (C) if requested by the Company, such Holder shall have furnished the Company, at the
Holder’s expense, with an opinion of counsel, reasonably satisfactory to the Company, to the effect that such disposition will not require registration of such Securities under the Securities Act. 

(b) Permitted Transfers. Permitted transfers with respect to Section 5(a) include (i) a transfer not involving a
change in beneficial ownership, or (ii) transactions involving the distribution without consideration of Securities by any Holder to (x) a parent, subsidiary or other affiliate of a Holder that is a corporation, (y) any of the
Holder’s partners, members or other equity owners, or retired partners or members, or to the estate of any of its partners, members or other equity owners or retired partners or members, or (z) a venture capital fund that is controlled by
or under common control with one or more general partners or managing members of, or shares the same management company with, the Holder; provided, in each case, that the Holder shall give written notice to the Company of the Holder’s
intention to effect such disposition and shall have furnished the Company with a detailed description of the manner and circumstances of the proposed disposition. 

(c) Investment Representation Statement. Unless the rights under this Warrant are exercised pursuant to an effective
registration statement under the Securities Act that includes the Shares with respect to which the Warrant was exercised, it shall be a condition to any exercise of the rights under this Warrant that the Holder shall have confirmed to the
satisfaction of the Company in writing, substantially in the form of Exhibit A-1, that the Shares so purchased are being acquired solely for the Holder’s own account and not as a nominee for any other party, for investment and not with a
view toward distribution or resale and that the Holder shall have confirmed such other matters related thereto as may be reasonably requested by the Company. 

(d) Securities Law Legend. The Securities shall (unless otherwise permitted by the provisions of this Warrant) be stamped or
imprinted with a legend substantially similar to the following (in addition to any legend required by state securities laws): 
 THE
SECURITIES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “ACT”), OR UNDER THE SECURITIES LAWS OF CERTAIN STATES. THESE SECURITIES MAY NOT BE OFFERED, SOLD OR OTHERWISE TRANSFERRED, PLEDGED OR
HYPOTHECATED EXCEPT AS PERMITTED UNDER THE ACT AND APPLICABLE STATE SECURITIES LAWS IN ACCORDANCE WITH 

  
 5 









 
APPLICABLE REGISTRATION REQUIREMENTS OR AN EXEMPTION THEREFROM. THE ISSUER OF THESE SECURITIES MAY REQUIRE AN OPINION OF COUNSEL REASONABLY SATISFACTORY TO THE ISSUER THAT SUCH OFFER, SALE OR
TRANSFER, PLEDGE OR HYPOTHECATION OTHERWISE COMPLIES WITH THE ACT AND ANY APPLICABLE STATE SECURITIES LAWS. THIS CERTIFICATE MUST BE SURRENDERED TO THE COMPANY OR ITS TRANSFER AGENT AS A CONDITION PRECEDENT TO THE SALE, TRANSFER, PLEDGE OR
HYPOTHECATION OF ANY INTEREST IN ANY OF THE SECURITIES REPRESENTED HEREBY. 
 (e) Market Stand-off Legend. The Shares and
common stock issued upon exercise hereof or conversion thereof shall also be stamped or imprinted with a legend in substantially the following form: 

THE SHARES REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO RESTRICTIONS ON TRANSFERABILITY AND RESALE, INCLUDING A LOCK-UP PERIOD IN THE EVENT
OF A PUBLIC OFFERING, AS SET FORTH IN THE WARRANT PURSUANT TO WHICH THESE SHARES WERE ISSUED, A COPY OF WHICH MAY BE OBTAINED AT THE PRINCIPAL OFFICE OF THE COMPANY. 

(f) Instructions Regarding Transfer Restrictions. The Holder consents to the Company making a notation on its records and giving
instructions to any transfer agent in order to implement the restrictions on transfer established in this Section 5. 
 (g)
Removal of Legend. The legend referring to federal and state securities laws identified in Section 5(d) stamped on a certificate evidencing the Shares (and the common stock issuable upon conversion thereof) and the stock transfer
instructions and record notations with respect to such securities shall be removed and the Company shall issue a certificate without such legend to the holder of such securities if (i) such securities are registered under the Securities Act, or
(ii) such holder provides the Company with an opinion of counsel reasonably acceptable to the Company to the effect that a sale or transfer of such securities may be made without registration or qualification. 

(h) No Transfers to Bad Actors; Notice of Bad Actor Status. The Holder agrees not to sell, assign, transfer, pledge or
otherwise dispose of any securities of the Company, or any beneficial interest therein, to any person (other than the Company) unless and until the proposed transferee confirms to the reasonable satisfaction of the Company that neither the proposed
transferee nor any of its directors, executive officers, other officers that may serve as a director or officer of any company in which it invests, general partners or managing members nor any person that would be deemed a beneficial owner of those
securities (in accordance with Rule 506(d) of the Securities Act) is subject to any of the “bad actor” disqualifications described in Rule 506(d)(1)(i) through (viii) under the Securities Act, except as set forth in
Rule 506(d)(2)(ii) or (iii) or (d)(3) under the Securities Act and disclosed, reasonably in advance of the transfer, in writing in reasonable detail to the Company. The Holder will promptly notify the Company in writing if the Holder or,
to the Holder’s knowledge, any person specified in Rule 506(d)(1) under the Securities Act becomes subject to any of the “bad actor” disqualifications described in Rule 506(d)(1)(i) through (viii) under the Securities
Act. 
 6. Adjustments. Subject to the expiration of this Warrant pursuant to Section 7, the number and kind of shares
purchasable hereunder and the Exercise Price therefor are subject to adjustment from time to time, as follows: 
 (a) Merger or
Reorganization. If at any time there shall be any reorganization, recapitalization, merger or consolidation (a “Reorganization”) involving the Company (other than as 

  
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otherwise provided for herein or as would cause the expiration of this Warrant under Section 7) in which shares of the Company’s stock are converted into or exchanged for securities,
cash or other property, then, as a part of such Reorganization, lawful provision shall be made so that the Holder shall thereafter be entitled to receive upon exercise of this Warrant, the kind and amount of securities, cash or other property of the
successor corporation resulting from such Reorganization, equivalent in value to that which a holder of the Shares deliverable upon exercise of this Warrant would have been entitled in such Reorganization if the right to purchase the Shares
hereunder had been exercised immediately prior to such Reorganization. In any such case, appropriate adjustment (as determined in good faith by the Board of Directors of the successor corporation) shall be made in the application of the provisions
of this Warrant with respect to the rights and interests of the Holder after such Reorganization to the end that the provisions of this Warrant shall be applicable after the event, as near as reasonably may be, in relation to any shares or other
securities deliverable after that event upon the exercise of this Warrant. 
 (b) Reclassification of Shares. If the
securities issuable upon exercise of this Warrant are changed into the same or a different number of securities of any other class or classes by reclassification, capital reorganization, conversion of all outstanding shares of the relevant class or
series (other than as would cause the expiration of this Warrant pursuant to Section 7) or otherwise (other than as otherwise provided for herein) (a “Reclassification”), then, in any such event, in lieu of the number of
Shares which the Holder would otherwise have been entitled to receive, the Holder shall have the right thereafter to exercise this Warrant for a number of shares of such other class or classes of stock that a holder of the number of securities
deliverable upon exercise of this Warrant immediately before that change would have been entitled to receive in such Reclassification, all subject to further adjustment as provided herein with respect to such other shares. 

(c) Subdivisions and Combinations. In the event that the outstanding shares of Common Stock are subdivided (by stock split, by
payment of a stock dividend or otherwise) into a greater number of shares of such securities, the number of Shares issuable upon exercise of the rights under this Warrant immediately prior to such subdivision shall, concurrently with the
effectiveness of such subdivision, be proportionately increased, and the Exercise Price shall be proportionately decreased, and in the event that the outstanding shares of Common Stock are combined (by reclassification or otherwise) into a lesser
number of shares of such securities, the number of Shares issuable upon exercise of the rights under this Warrant immediately prior to such combination shall, concurrently with the effectiveness of such combination, be proportionately decreased, and
the Exercise Price shall be proportionately increased. 
 (d) Notice of Adjustments. Upon any adjustment in accordance with
this Section 6, the Company shall give notice thereof to the Holder, which notice shall state the event giving rise to the adjustment, the Exercise Price as adjusted and the number of securities or other property purchasable upon the exercise
of the rights under this Warrant, setting forth in reasonable detail the method of calculation of each. The Company shall, upon the written request of any Holder, furnish or cause to be furnished to such Holder a certificate setting forth
(i) such adjustments, (ii) the Exercise Price at the time in effect and (iii) the number of securities and the amount, if any, of other property that at the time would be received upon exercise of this Warrant. 

7. Expiration of the Warrant. This Warrant shall expire and shall no longer be exercisable as of the earlier of: 

(a) 5:00 p.m., Eastern time, on August 3, 2024; or 

(b) the consummation of a Change in Control (as defined below). 

  
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 For the purpose of this Section 7, “Change of Control” shall mean
(i) (A) any consolidation or merger of the Company with or into any other corporation or other entity or person, or any other corporate reorganization, in which the capital stock of the Company immediately prior to such consolidation,
merger or reorganization, represents less than a majority of the voting power of the surviving entity (or, if the surviving entity is a wholly owned subsidiary, its parent) immediately after such consolidation, merger or reorganization; or
(B) any transaction or series of related transactions to which the Company is a party in which fifty percent (50%) or more of the Company’s voting power is transferred; provided that a Change of Control shall not include (x) any
consolidation or merger effected exclusively to change the domicile of the Company, or (y) any transaction or series of transactions principally for bona fide equity financing purposes in which cash is received by the Company or any successor
or indebtedness of the Company is cancelled or converted or a combination thereof; and (ii) any sale, lease, exclusive license or other disposition of all or substantially all of the assets of the Company. 

8. No Rights as a Stockholder. Nothing contained herein shall entitle the Holder to any rights as a stockholder of the Company or to be
deemed the holder of any securities that may at any time be issuable on the exercise of the rights hereunder for any purpose nor shall anything contained herein be construed to confer upon the Holder, as such, any right to vote for the election of
directors or upon any matter submitted to stockholders at any meeting thereof, or to give or withhold consent to any corporate action (whether upon any recapitalization, issuance of stock, reclassification of stock, change of par value or change of
stock to no par value, consolidation, merger, conveyance or otherwise) or to receive notice of meetings, or to receive dividends or subscription rights or any other rights of a stockholder of the Company until the rights under the Warrant shall have
been exercised and the Shares purchasable upon exercise of the rights hereunder shall have become deliverable as provided herein. 
 9.
Market Stand-off Agreement. The Holder of this Warrant hereby agrees that such Holder shall not sell or otherwise 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, of any common stock (or other securities) of the Company held by the Holder (other than those included in the registration) during the one hundred eighty (180) day period following the effective date of a
registration statement of the Company filed under the Securities Act (or such other period as may be requested by the Company or an underwriter to accommodate regulatory restrictions on (i) the publication or other distribution of research
reports and (ii) analyst recommendations and opinions, including, but not limited to, the restrictions contained in NASD Rule 2711(f)(4) or NYSE Rule 472(f)(4), or any successor provisions or amendments thereto), provided that:
(i) such agreement shall apply only to the Company’s Initial Public Offering and (ii) all officers and directors of the Company and holders of at least one percent (1%) of the Company’s voting securities are bound by and
have entered into similar agreements. The obligations described in this section shall not apply to a registration relating solely to employee benefit plans on Form S-l or Form S-8 or similar forms that may be promulgated in the future, or a
registration relating solely to a transaction on Form S-4 or similar forms that may be promulgated in the future. The Company may impose stop-transfer instructions and may stamp each such certificate with the legend set forth in Section 5(e)
with respect to the shares of common stock (or other securities) subject to the foregoing restriction until the end of such one hundred eighty (180) day (or other) period. 

10. Miscellaneous. 
 (a)
Amendments. Except as expressly provided herein, neither this Warrant nor any term hereof may be amended, waived, discharged or terminated other than by a written instrument referencing this Warrant and signed by the Company and the
holders of warrants representing not less than a majority of the Shares issuable upon exercise of any and all outstanding Warrants, which majority does not need to include the consent of the Holder. Any amendment, waiver, discharge or termination
effected in accordance with this Section 10(a) shall be binding upon each holder of the Warrants, each future holder of such Warrants and the Company; provided, however, that no special consideration or inducement may be given to any
such holder in connection with such consent that is not given ratably to all such holders, and that such amendment must 

  
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apply to all such holders equally and ratably in accordance with the number of shares of common stock issuable upon exercise of the Warrants. The Company shall promptly give notice to all holders
of Warrants of any amendment effected in accordance with this Section 10(a). 
 (b) Waivers. No waiver of any single
breach or default shall be deemed a waiver of any other breach or default theretofore or thereafter occurring. 
 (c) Notices.
All notices and other communications required or permitted hereunder shall be in writing and shall be mailed by registered or certified mail, postage prepaid, sent by facsimile or electronic mail (if to the Holder) or otherwise delivered by hand,
messenger or courier service addressed: 
 (i) if to the Holder, to the Holder at the Holder’s address, facsimile number or electronic
mail address as shown in the Company’s records, as may be updated in accordance with the provisions hereof, or until any such Holder so furnishes an address, facsimile number or electronic mail address to the Company, then to and at the
address, facsimile number or electronic mail address of the last holder of this Warrant for which the Company has contact information in its records; or 

(ii) if to the Company, to the attention of the Chief Financial Officer of the Company at the Company’s address as shown on the
signature page hereto, or at such other current address as the Company shall have furnished to the Holder, with a copy (which shall not constitute notice) to Herbert Fockler, Wilson Sonsini Goodrich & Rosati, P.C., 650 Page Mill Road, Palo
Alto, CA 94304. 
 Each such notice or other communication shall for all purposes of this Warrant be treated as effective or having been given (i) if
delivered by hand, messenger or courier service, when delivered, or (ii) if sent by mail, at the earlier of its receipt or 72 hours after the same has been deposited in a regularly maintained receptacle for the deposit of the United States
mail, addressed and mailed as aforesaid, or (iii) if sent by facsimile, upon confirmation of facsimile transfer or, if sent by electronic mail, upon confirmation of delivery when directed to the relevant electronic mail address. In the event of
any conflict between the Company’s books and records and this Warrant or any notice delivered hereunder, the Company’s books and records will control absent fraud or error. 

(d) Governing Law. This Warrant and all actions arising out of or in connection with this Warrant shall be governed by and
construed in accordance with the laws of the State of Delaware, without regard to the conflicts of law provisions of the State of Delaware, or of any other state. 

(e) Jurisdiction and Venue. Each of the Holder and the Company irrevocably consents to the exclusive jurisdiction and venue of
any court within Harris County, State of Texas, in connection with any matter based upon or arising out of this Warrant or the matters contemplated herein, and agrees that process may be served upon them in any manner authorized by the laws of the
State of Texas for such persons. 
 (f) Titles and Subtitles. The titles and subtitles used in this Warrant are used for
convenience only and are not to be considered in construing or interpreting this Warrant. All references in this Warrant to sections, paragraphs and exhibits shall, unless otherwise provided, refer to sections and paragraphs hereof and exhibits
attached hereto. 
 (g) Severability. If any provision of this Warrant becomes or is declared by a court of competent
jurisdiction to be illegal, unenforceable or void, portions of such provision, or such provision in its entirety, to the extent necessary, shall be severed from this Warrant, and such illegal, unenforceable or void provision shall be replaced with a
valid and enforceable provision that will achieve, to the extent possible, the same economic, business and other purposes of the illegal, unenforceable or void provision. The balance of this Warrant shall be enforceable in accordance with its terms.


  
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 (h) Rights and Obligations Survive Exercise of the Warrant. Except as otherwise
provided herein, the rights and obligations of the Company and the Holder under this Warrant shall survive exercise of this Warrant. 
 (i)
Entire Agreement. Except as expressly set forth herein, this Warrant (including the exhibits attached hereto) constitutes the entire agreement and understanding of the Company and the Holder with respect to the subject matter hereof
and supersede all prior agreements and understandings relating to the subject matter hereof. 
 (signature page follows)


  
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 The Company signs this Warrant as of the date stated on the first page. 

 

			
	MULTIVIR, INC.
		
	By:	 	  

	Name:	 	Robert E. Sobol,
	Title:	 	Chief Executive Officer
	
	Address:
	
	410 Pierce Street, Suite 325
	Houston, TX 77002


 (Signature Page to Warrant to Purchase Shares of Common Stock of MultiVir,
Inc.) 








 EXHIBIT A 

NOTICE OF EXERCISE 
  

	TO:	  MultiVir, Inc. (the “Company”) 

 Attention:
    Secretary 
  

	(1)	Exercise. The undersigned elects to purchase the following pursuant to the terms of the attached warrant: 


 

			
	Number of shares:	  	  

		
	Type of security:	  	  



  

	(2)	Method of Exercise. The undersigned elects to exercise the attached warrant pursuant to: 

  

			
	 ̈	  	A cash payment or cancellation of indebtedness, and tenders herewith payment of the purchase price for such shares in full, together with all applicable transfer taxes, if any.
		
	 ̈	  	The net issue exercise provisions of Section 2(b) of the attached warrant.


  

	(3)	Conditional Exercise. Is this a conditional exercise pursuant to Section 2(e): 

  

											
	 ̈	    	Yes	  		  	 ̈	    	No	  	


 If “Yes,” indicate the applicable condition: 

 

	
	  




 

	(4)	Stock Certificate. Please issue a certificate or certificates representing the shares in the name of: 

  

					
	 ̈	  	The undersigned	  	
			
	 ̈	  	Other—Name:	  	  

			
		  	 Address:
	  	  

			
		  		  	  



  

	(5)	Unexercised Portion of the Warrant. Please issue a new warrant for the unexercised portion of the attached warrant in the name of: 


 

					
	 ̈	  	The undersigned	  	
			
	 ̈	  	Other—Name:	  	  

			
		  	 Address:
	  	  

			
	 ̈	  	Not applicable	  	



  
 A-1 










	(6)	Investment Intent. The undersigned represents and warrants that the aforesaid shares are being acquired for investment for its own account, not as a nominee or agent, and not with a view to, or for resale in
connection with, the distribution thereof, and that the undersigned has no present intention of selling, granting any participation in, or otherwise distributing the shares, nor does it have any contract, undertaking, agreement or arrangement for
the same. 

  

	(7)	Investment Representation Statement and Market Stand-Off Agreement. The undersigned has executed, and delivers herewith, an Investment Representation Statement and Market Stand-Off Agreement in a form
substantially similar to the form attached to the warrant as Exhibit A-1. 

  

	(8)	Consent to Receipt of Electronic Notice. Subject to the limitations set forth in Delaware General Corporation Law §232(e), the undersigned consents to the delivery of any notice to stockholders given by the
Company under the Delaware General Corporation Law or the Company’s certificate of incorporation or bylaws by (i) facsimile telecommunication to the facsimile number provided below (or to any other facsimile number for the undersigned in
the Company’s records), (ii) electronic mail to the electronic mail address provided below (or to any other electronic mail address for the undersigned in the Company’s records), (iii) posting on an electronic network together
with separate notice to the undersigned of such specific posting or (iv) any other form of electronic transmission (as defined in the Delaware General Corporation Law) directed to the undersigned. This consent may be revoked by the undersigned
by written notice to the Company and may be deemed revoked in the circumstances specified in Delaware General Corporation Law §232. 

  

	
	  

	 (Print name of the warrant holder)

 

	  

	 (Signature)

 

	  

	 (Name and title of signatory, if applicable)

 

	  

	 (Date)
  

	  

	(Fax number)
	
	  

	(Email address)


 (Signature page to the Notice of Exercise) 

  
 A-2 









 EXHIBIT A-l 

INVESTMENT REPRESENTATION STATEMENT 

AND 
 MARKET STAND-OFF
AGREEMENT 
  

			
	INVESTOR:	  	  

		
	COMPANY:	  	MULTIVIR, INC.
		
	SECURITIES:	  	THE WARRANT ISSUED AS OF DECEMBER     , 2014 (THE “WARRANT”) AND THE SECURITIES ISSUED OR ISSUABLE UPON EXERCISE THEREOF (INCLUDING UPON SUBSEQUENT CONVERSION OF THOSE
SECURITIES)
		
	DATE:	  	                    

 In connection with the purchase or acquisition of the above-listed Securities, the undersigned Investor
represents and warrants to, and agrees with, the Company as follows: 
 1. No Registration. The Investor understands that the
Securities have not been, and will not be, registered under the Securities Act of 1933, as amended (the “Securities Act”), by reason of a specific exemption from the registration provisions of the Securities Act, the
availability of which depends upon, among other things, the bona fide nature of the investment intent and the accuracy of the Investor’s representations as expressed herein or otherwise made pursuant hereto. 

2. Investment Intent. The Investor is acquiring the Securities for investment for its own account, not as a nominee or agent, and not
with a view to, or for resale in connection with, any distribution thereof. The Investor has no present intention of selling, granting any participation in, or otherwise distributing the Securities, nor does it have any contract, undertaking,
agreement or arrangement for the same. 
 3. Investment Experience. The Investor has substantial experience in evaluating and
investing in private placement transactions of securities in companies similar to the Company, and has such knowledge and experience in financial or business matters so that it is capable of evaluating the merits and risks of its investment in the
Company and protecting its own interests. 
 4. Speculative Nature of Investment. The Investor understands and acknowledges that the
Company has a limited financial and operating history and that its investment in the Company is highly speculative and involves substantial risks. The Investor can bear the economic risk of its investment and is able, without impairing its financial
condition, to hold the Securities for an indefinite period of time and to suffer a complete loss of its investment. 
 5. Access to
Data. The Investor has had an opportunity to ask questions of officers of the Company, which questions were answered to its satisfaction. The Investor believes that it has received all the information that it considers necessary or appropriate
for deciding whether to acquire the Securities. The Investor understands that any such discussions, as well as any information issued by the Company, were intended to describe certain aspects of the Company’s business and prospects, but were
not necessarily a thorough or exhaustive description. The Investor acknowledges that any business plans prepared by the Company have been, and continue to be, subject to change and that any projections included in such business plans or otherwise
are necessarily speculative in nature, and it can be expected that some or all of the assumptions underlying the projections will not materialize or will vary significantly from actual results. 

  
 A-1-1 









 6. Accredited Investor. The Investor is an “accredited investor” within the
meaning of Regulation D, Rule 501(a), promulgated by the Securities and Exchange Commission and agrees to submit to the Company such further assurances of such status as may be reasonably requested by the Company. 

7. Residency. The residency of the Investor (or, in the case of a partnership or corporation, such entity’s principal place of
business) is correctly set forth on the signature page hereto. 
 8. Restrictions on Resales. The Investor acknowledges that the
Securities must be held indefinitely unless subsequently registered under the Securities Act or an exemption from such registration is available. The Investor is aware of the provisions of Rule 144 promulgated under the Securities Act, which
permit resale of shares purchased in a private placement subject to the satisfaction of certain conditions, which may include, among other things, the availability of certain current public information about the Company; the resale occurring not
less than a specified period after a party has purchased and paid for the security to be sold; the number of shares being sold during any three-month period not exceeding specified limitations; the sale being effected through a “broker’s
transaction,” a transaction directly with a “market maker” or a “riskless principal transaction” (as those terms are defined in the Securities Act or the Securities Exchange Act of 1934, as amended, and the rules and
regulations promulgated thereunder); and the filing of a Form 144 notice, if applicable. The Investor acknowledges and understands that the Company may not be satisfying the current public information requirement of Rule 144 at the time the
Investor wishes to sell the Securities and that, in such event, the Investor may be precluded from selling the Securities under Rule 144 even if the other applicable requirements of Rule 144 have been satisfied. The Investor understands
and acknowledges that, in the event the applicable requirements of Rule 144 are not met, registration under the Securities Act or an exemption from registration will be required for any disposition of the Securities. The Investor understands
that, although Rule 144 is not exclusive, the Securities and Exchange Commission has expressed its opinion that persons proposing to sell restricted securities received in a private offering other than in a registered offering or pursuant to
Rule 144 will have a substantial burden of proof in establishing that an exemption from registration is available for those offers or sales and that those persons and the brokers who participate in the transactions do so at their own risk. 

9. No Public Market. The Holder understands and acknowledges that no public market now exists for any of the securities issued by the
Company and that the Company has made no assurances that a public market will ever exist for the Company’s securities. 
 10.
Brokers and Finders. The Investor has not engaged any brokers, finders or agents in connection with the Securities, and the Company has not incurred nor will incur, directly or indirectly, as a result of any action taken by the Investor, any
liability for brokerage or finders’ fees or agents’ commissions or any similar charges in connection with the Securities. 
 11.
Legal Counsel. The Investor has had the opportunity to review the Warrant, the exhibits and schedules attached thereto and the transactions contemplated by the Warrant with its own legal counsel. The Investor is not relying on any statements
or representations of the Company or its agents for legal advice with respect to this investment or the transactions contemplated by the Warrant. 

12. Tax Advisors. The Investor has reviewed with its own tax advisors the U.S. federal, state and local and non-U.S. tax consequences
of this investment and the transactions contemplated by the Warrant. With respect to such matters, the Investor relies solely on such advisors and not on any statements or representations of the Company or any of its agents, written or oral. The
Investor understands that it (and not the Company) shall be responsible for its own tax liability that may arise as a result of this investment or the transactions contemplated by the Warrant. 

  
 A-1-2 









 13. Market Stand-off Agreement. The Investor agrees that the Investor shall not sell or
otherwise 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, of any Common Stock (or other securities) of the Company held by the Investor
(other than those included in the registration) during the one hundred eighty (180) day period following the effective date of the registration statement for the Company’s Initial Public Offering filed under the Securities Act (or such
other period as may be requested by the Company or an underwriter to accommodate regulatory restrictions on (i) the publication or other distribution of research reports and (ii) analyst recommendations and opinions, including, but not
limited to, the restrictions contained in NASD Rule 2711(f)(4) or NYSE Rule 472(f)(4), or any successor provisions or amendments thereto. The obligations described in this section shall not apply to a registration relating solely to
employee benefit plans on Form S-l or Form S-8 or similar forms that may be promulgated in the future, or a registration relating solely to a transaction on Form S-4 or similar forms that may be promulgated in the future. The Company may impose
stop-transfer instructions and may stamp each certificate with a legend with respect to the shares of Common Stock (or other securities) subject to the foregoing restriction until the end of such one hundred eighty (180) day (or other) period.
The Investor agrees to execute a market stand-off agreement with the relevant underwriters in customary form consistent with the provisions of this section. 

(signature page follows) 

  
 A-1-3 









 The Investor is signing this Investment Representation Statement and Market Stand-Off Agreement
on the date first written above. 
  

	
	INVESTOR
	
	  
 (Print name
of the investor)

	
	  

(Signature)

	
	  
 (Name and
title of signatory, if applicable)

	
	  
 (Street
address)

	
	  
 (City,
state and ZIP)




  
 A-1-4 









 EXHIBIT B 

ASSIGNMENT FORM 
  

			
	ASSIGNOR:	  	  

		
	COMPANY:	  	MULTIVIR, INC.
		
	WARRANT:	  	THE WARRANT TO PURCHASE SHARES OF COMMON STOCK ISSUED AS OF DECEMBER     , 2014 (THE “WARRANT”)
		
	DATE:	  	                    

  

	(1)	Assignment. The undersigned registered holder of the Warrant (“Assignor”) assigns and transfers to the assignee named below (“Assignee”) all of the rights of
Assignor under the Warrant, with respect to the number of shares set forth below: 

 Name of
Assignee:                                       
                                         
                                         
          
 Address of
Assignee:                                       
                                         
                                         
      
  

                       
                                         
                                         
                
 Number of Shares
Assigned:                                       
                                         
                                   

and does irrevocably constitute and appoint
                     as attorney to make such transfer on the books of MultiVir, Inc., maintained for the purpose, with full power of
substitution in the premises. 
  

	(2)	Obligations of Assignee. Assignee agrees to take and hold the Warrant and any shares of stock to be issued upon exercise of the rights thereunder (and any shares issuable upon conversion thereof) (the
“Securities”) subject to, and to be bound by, the terms and conditions set forth in the Warrant to the same extent as if Assignee were the original holder thereof. 


 

	(3)	Investment Intent. Assignee represents and warrants that the Securities are being acquired for investment for its own account, not as a nominee or agent, and not with a view to, or for resale in connection with,
the distribution thereof, and that Assignee has no present intention of selling, granting any participation in, or otherwise distributing the shares, nor does it have any contract, undertaking, agreement or arrangement for the same.


  

	(4)	Investment Representation Statement and Market Stand-Off Agreement. Assignee has executed, and delivers herewith, an Investment Representation Statement and Market Stand-Off Agreement in a form substantially
similar to the form attached to the Warrant as Exhibit A-1. 









 Assignor and Assignee are signing this Assignment Form on the date first set forth above. 

 

					
	ASSIGNOR	 		 	ASSIGNEE
			
	  
	 		 	  

	(Print name of Assignor)	 		 	(Print name of Assignee)
			
	  
	 		 	  

	(Signature of Assignor)	 		 	(Signature of Assignee)
			
	  
	 		 	  

	(Print name of signatory, if applicable)	 		 	(Print name of signatory, if applicable)
			
	  
	 		 	  

	(Print title of signatory, if applicable)	 		 	(Print title of signatory, if applicable)
			
	Address:	 		 	Address: