FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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(Print or Type Responses)

1. Name and Address of Reporting Person * KIRK RANDAL J   2. Issuer Name and Ticker or Trading Symbol ZIOPHARM ONCOLOGY INC [ZIOP] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director _____ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) C/O THIRD SECURITY, LLC, 1881 GROVE AVENUE 3. Date of Earliest Transaction (Month/Day/Year) 04/30/2018 (Street) RADFORD, VA 24141 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Filing(Check Applicable Line) ___ Form filed by One Reporting Person _X_ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Series 1 Preferred Stock

(1)

04/30/2018

J

1,232

(1)

(1)

Common Stock

(1)

(2)

124,500 (2)

I

by Intrexon (3)

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
KIRK RANDAL J C/O THIRD SECURITY, LLC 1881 GROVE AVENUE RADFORD, VA 24141	X
INTREXON CORP C/O LEGAL DEPARTMENT 20374 SENECA MEADOWS PARKWAY GERMANTOWN, MD 20876		X

Signatures

/s/ Randal J. Kirk		04/30/2018
**Signature of Reporting Person		Date
/s/ Randal J. Kirk, CEO of Intrexon Corporation		04/30/2018
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	Each share of Series 1 Preferred Stock ("Preferred Stock") has a stated value of $1,200, subject to appropriate adjustment in the event of any stock dividend, stock split, combination or other recapitalization with respect to the shares of Preferred Stock. The shares of Preferred Stock shall automatically convert into shares of the issuer's common stock upon the date of commercialization of a product pursuant to the collaboration between Intrexon Corporation ("Intrexon") and the issuer, subject to conversion limitations set forth in the Securities Issuance Agreement entered into between the issuer and Intrexon on June 29, 2016 (the "Issuance Agreement"). The conversion price in connection with such automatic conversion shall be determined as set forth in the Amended and Restated Certificate of Designation, Preferences and Rights of Series 1 Preferred Stock, which the issuer has filed as an exhibit to its Amendment to Current Report on Form 8-K/A, dated July 1, 2016.
(2)	Intrexon received the shares of Preferred Stock as payment-in-kind dividends in connection with its ownership of shares of Preferred Stock. The holders of Preferred Stock are entitled to receive a monthly dividend payable in additional shares of Preferred Stock equal to $12.00 per share of Preferred Stock per month (subject to adjustment), divided by the stated value of $1,200, rounded down to the nearest whole share.
(3)	Randal J. Kirk, directly and through certain affiliates, is the largest shareholder of Intrexon and serves as Intrexon's Chairman of the Board and Chief Executive Officer. Mr. Kirk may therefore be deemed to have voting and dispositive power over the shares of the issuer owned by Intrexon. Shares held by Intrexon may be deemed to be indirectly beneficially owned (as defined under Rule 13d-3 promulgated under the Securities Exchange Act of 1934, as amended) by Mr. Kirk. Mr. Kirk disclaims beneficial ownership of such shares, except to the extent of any pecuniary interest therein.

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