As filed with the Securities and Exchange Commission on May 4, 2015.

Registration No. 333-203086

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

AMENDMENT NO. 2

TO

FORM S-1

REGISTRATION STATEMENT

Under

The Securities Act of 1933

MULTIVIR INC.

(Exact name of Registrant as specified in its charter)

410 Pierce Street, Suite 325

Houston, Texas 77002

(Address, including zip code, and telephone number, including area code, of Registrant’s principal executive offices)

Robert E. Sobol, M.D.

Chief Executive Officer

410 Pierce Street, Suite 325

Houston, Texas 77002

(832) 431-3555

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copies to:

Approximate date of commencement of proposed sale to the public: As soon as practicable after this registration statement becomes effective.

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, check the following box:  ¨

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ¨

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ¨

If this Form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act. (Check one):

The Registrant hereby amends this Registration Statement on such date or dates as may be necessary to delay its effective date until the Registrant shall file a further amendment which specifically states that this Registration Statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933 or until the Registration Statement shall become effective on such date as the Commission, acting pursuant to said Section 8(a), may determine.

EXPLANATORY NOTE

This Amendment No. 2 to the Registration Statement (File No. 333-203086) is being filed solely to file Exhibits 1.1, 5.1 and 23.2 and to update the Exhibit Index accordingly. No changes have been made to the Prospectus which forms a part of the Registration Statement. Accordingly, it has been omitted.

PART II — INFORMATION NOT REQUIRED IN PROSPECTUS

The following table sets forth all expenses to be paid by the Registrant, other than underwriting discounts and commissions, upon the completion of this offering. All amounts shown are estimates except for the SEC registration fee, NASDAQ listing fee and FINRA filing fee.

Section 145 of the Delaware General Corporation Law authorizes a corporation’s board of directors to grant, and authorizes a court to award, indemnity to officers, directors and other corporate agents.

Upon the completion of this offering, as permitted by Section 102(b)(7) of the Delaware General Corporation Law, the Registrant’s amended and restated certificate of incorporation will include provisions that eliminate the personal liability of its directors for monetary damages for breach of their fiduciary duty as directors, excluding liability for any breach of the duty of loyalty and upon certain other circumstances.

In addition, as permitted by Section 145 of the Delaware General Corporation Law, the amended and restated certificate of incorporation and amended and restated bylaws of the Registrant generally will provide that:

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The Registrant’s policy is to enter into separate indemnification agreements with each of its directors and officers that provide the maximum indemnity allowed to directors and executive officers by Section 145 of the Delaware General Corporation Law and also to provide for certain additional procedural protections. The Registrant also maintains directors and officers insurance to insure such persons against certain liabilities.

These indemnification provisions and the indemnification agreements entered into between the Registrant and its officers and directors may be sufficiently broad to permit indemnification of the Registrant’s officers and directors for liabilities (including reimbursement of expenses incurred) arising under the Securities Act.

The underwriting agreement to be filed as Exhibit 1.1 to this registration statement provides for indemnification by the underwriters of the Registrant and its officers and directors for certain liabilities arising under the Securities Act and otherwise.

Since January 1, 2012, the Registrant has issued the following unregistered securities, after giving effect to the 1-for-1.5 reverse stock split of the Registrant’s common stock which was effected by the Registrant in April 2015:

Promissory Notes, Common Stock and Warrants

The Registrant sold an aggregate of $3,736,783 in promissory notes to its controlling stockholder, Pope Investments II, LLC, or Pope, since January 1, 2012. Some of these promissory notes bore interest at a rate of 1% per annum; the remainder were interest-free. All unpaid principal and accrued interest on the promissory notes was due and payable on demand by the lender.

The Registrant subsequently entered into a note conversion agreement with Pope, pursuant to which the outstanding balance of all promissory notes issued to Pope, including promissory notes issued prior to January 1, 2012, together with all accrued and unpaid interest were converted into an aggregate of 3,580,627 shares of the Registrant’s common stock.

The Registrant entered into a credit facility agreement with Pope pursuant to which the Registrant may borrow an aggregate of $10 million in exchange for the issuance of (x) promissory notes with an annual interest rate of 6% per annum and (y) warrants to purchase the Registrant’s common stock. As of April 22, 2015, the Registrant has issued an aggregate of $0.8 million in promissory notes pursuant to the credit facility with an annual rate of 6% per annum. As of April 22, 2015, the Registrant has issued warrants to Pope to purchase 43,306 shares of common stock with an exercise price of $18.75 per share. In addition, in connection with any further amounts drawn under the credit facility, the Registrant will issue warrants to Pope to purchase 0.053 shares of common stock per $1.00 loaned to the Registrant under the credit facility at an exercise price of $18.75 per share.

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Option Grants and Common Stock Exercises

From January 1, 2012 through April 22, 2015, the Registrant granted to its officers, directors, employees, consultants and other service providers options to purchase an aggregate of 1,142,336 shares of common stock under its 2014 Stock Option and Grant Plan at an exercise price of $7.02 per share. Of the options granted, options to purchase 789,997 shares of common stock were granted to four executives with exercise prices of $7.02 per share per share, options to purchase 129,998 shares of common stock were granted to four other consultants with exercise prices of $7.02 per share. In addition, options to purchase 148,497 shares of our common stock were granted to several of our directors and to contractors who will become employees upon the completion of this offering at an exercise price of $13.00 per share, the midpoint of the estimated price range set forth on the cover page of this prospectus.

None of the foregoing transactions involved any underwriters, underwriting discounts or commissions or any public offering.

The offers, sales and issuances of the securities described above were deemed to be exempt from registration under the Securities Act under either (i) Rule 701 promulgated under the Securities Act as offers and sales of securities pursuant to certain compensatory benefit plans and contracts relating to compensation in compliance with Rule 701 or (ii) Section 4(2) of the Securities Act as transactions by an issuer not involving any public offering. The recipients of securities in each of these transactions represented their intention to acquire the securities for investment only and not with a view to or for sale in connection with any distribution thereof, and appropriate legends were affixed to the stock certificates and instruments issued in such transactions. All recipients had adequate access, through their relationships with the Registrant, to information about the Registrant.

(a) Exhibits.

The Registrant has filed the exhibits listed on the accompanying Exhibit Index of this Registration Statement, which is incorporated by reference herein.

(b) Financial Statement Schedules.

All financial statement schedules are omitted because the information called for is not required or is shown either in the consolidated financial statements or in the notes thereto.

The undersigned Registrant hereby undertakes to provide to the underwriters at the closing specified in the underwriting agreement certificates in such denominations and registered in such names as required by the underwriters to permit prompt delivery to each purchaser.

Insofar as indemnification for liabilities arising under the Securities Act of 1933 may be permitted to directors, officers, and controlling persons of the Registrant pursuant to the foregoing provisions, or otherwise, the Registrant has been advised that in the opinion of the Securities and Exchange Commission such indemnification is against public policy as expressed in the Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the Registrant of expenses incurred or paid by a director, officer, or controlling person of the Registrant in the successful defense of any action, suit, or proceeding) is asserted by such director, officer, or controlling person in connection with the securities being registered, the Registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question

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whether such indemnification by it is against public policy as expressed in the Act and will be governed by the final adjudication of such issue.

The undersigned Registrant hereby undertakes that:

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SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, the Registrant has duly caused this registration statement on Form S-1 to be signed on its behalf by the undersigned, thereunto duly authorized, in Houston, Texas, on the 4^th day of May, 2015.

Pursuant to the requirements of the Securities Act of 1933, this registration statement on Form S-1 has been signed by the following persons in the capacities and on the dates indicated.

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EXHIBIT INDEX