Phone: 832 ###-###-#### Fax: 858 ###-###-####

Exhibit 10.39

				Houston Technology Center Suite 325 410 Pierce Street Houston, TX 77002
		Phone: 832 ###-###-#### Fax: 858 ###-###-####

March 31, 2015

Sunil Chada, PhD

PSYGEN, Inc.

Dear Dr. Chada:

Both you and MultiVir Inc. (the “Company”) acknowledge that a Trigger Event as defined in the Consulting Letter has not been completed as of March 31, 2015. In that regard, both you and the Company agree that the second full paragraph of page 2 of the Consulting Letter shall be amended and restated in its entirety to read as follows:

If the Company does not complete a Trigger Event on or before June 30, 2015, this Agreement shall terminate on June 30, 2015; provided, however, that this agreement shall continue after June 30, 2015 unless terminated upon 30-days prior written notice by either party.

Except as expressly amended hereby and by the First Amendment to Consulting Letter dated July 22, 2014 the terms and conditions of the Consulting Letter shall remain in full force and effect. Kindly countersign a copy of this letter and return it to me to evidence your acceptance of this amendment.