Ownership Submission
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 __X__ 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)
06/04/2015
(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
Common Stock 06/04/2015   J(1)   17,830,305 (1) D (1) 0 I by Intrexon Corporation (2)
Common Stock 06/04/2015   J(1)   3,479,006 (1) A (1) 3,479,006 I by R.J. Kirk DOT (3)
Common Stock 06/04/2015   J(1)   23,349 (1) A (1) 23,349 I by JPK 2008 (3)
Common Stock 06/04/2015   J(1)   23,504 (1) A (1) 23,504 I by MGK 2008 (3)
Common Stock 06/04/2015   J(1)   40,954 (1) A (1) 40,954 I by ZSK 2008 (3)
Common Stock 06/04/2015   J(1)   240 (1) A (1) 240 I by Lotus (3)
Common Stock 06/04/2015   J(1)   53,245 (1) A (1) 53,245 I by Staff 2001 (3)
Common Stock 06/04/2015   J(1)   9,537 (1) A (1) 9,537 I by Sr. Staff (3)
Common Stock 06/04/2015   J(1)   337,333 (1) A (1) 337,333 I by JPK 2009 (3)
Common Stock 06/04/2015   J(1)   358,386 (1) A (1) 358,386 I by MGK 2009 (3)
Common Stock 06/04/2015   J(1)   34,318 (1) A (1) 34,318 I by ZSK 2009 (3)
Common Stock 06/04/2015   J(1)   29,066 (1) A (1) 29,066 I by ADC 2010 (3)
Common Stock 06/04/2015   J(1)   154,181 (1) A (1) 154,181 I by MGK 2011 (3)
Common Stock 06/04/2015   J(1)   138,975 (1) A (1) 138,975 I by JPK 2012 (3)
Common Stock 06/04/2015   J(1)   61,262 (1) A (1) 61,262 I by Kellie L. Banks LTT (3)
Common Stock 06/04/2015   J(1)   1,013,146 (1) A (1) 2,359,608 I by Kapital Joe (4)
Common Stock 06/04/2015   J(1)   889,513 (1) A (1) 889,513 I by Mascara Kaboom (4)
Common Stock 06/04/2015   J(1)   395,791 (1) A (1) 395,791 I by Senior Staff 2008 (4)
Common Stock 06/04/2015   J(1)   222,680 (1) A (1) 222,680 I by Staff 2010 (4)
Common Stock 06/04/2015   J(1)   111,339 (1) A (1) 111,339 I by Incentive 2010 (4)
Common Stock 06/04/2015   J(1)   352,477 (1) A (1) 352,477 I by Senior Staff 2007 (4)
Common Stock 06/04/2015   J(1)   176,238 (1) A (1) 176,238 I by Staff 2007 (4)
Common Stock 06/04/2015   J(1)   58,746 (1) A (1) 58,746 I by Incentive 2007 (4)
Common Stock 06/04/2015   J(1)   173,111 (1) A (1) 173,111 I by Staff 2009 (4)
Common Stock 06/04/2015   J(1)   86,556 (1) A (1) 86,556 I by Incentive 2009 (4)
Common Stock               95,648 D  

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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

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   X    
INTREXON CORP
C/O LEGAL DEPARTMENT
20374 SENECA MEADOWS PARKWAY
GERMANTOWN, MD 20876
    X    

Signatures

 /s/ Randal J. Kirk, CEO of Intrexon Corporation   06/08/2015
**Signature of Reporting Person Date

 /s/ Randal J. Kirk   06/08/2015
**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) Intrexon Corporation declared a dividend of shares of ZIOPHARM Oncology, Inc. common stock held by it to its holders of record as of June 4, 2015.
(2) Randal J. Kirk, directly and through certain affiliates, has voting and dispositive power over a majority of the outstanding capital stock of Intrexon Corporation. Mr. Kirk may therefore be deemed to have voting and dispositive power over the shares of the issuer owned by Intrexon Corporation. Shares held by Intrexon Corporation 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.
(3) Randal J. Kirk controls each of Randal J. Kirk Declaration of Trust ("R.J. Kirk DOT"), JPK 2008, LLC ("JPK 2008"), MGK 2008, LLC ("MGK 2008"), ZSK 2008, LLC ("ZSK 2008"), Lotus Capital (2000) Co., Inc. ("Lotus"), Third Security Staff 2001 LLC ("Staff 2001"), Third Security Senior Staff LLC ("Sr. Staff"), JPK 2009, LLC ("JPK 2009"), MGK 2009, LLC ("MGK 2009"), ZSK 2009, LLC ("ZSK 2009"), ADC 2010, LLC ("ADC 2010"), MGK 2011, LLC ("MGK 2011"), JPK 2012, LLC ("JPK 2012") and Kellie L. Banks (2009) Long Term Trust ("Kellie L. Banks LTT"). Shares held by these entities may be deemed to be 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.
(4) Randal J. Kirk controls each of Kapital Joe, LLC ("Kapital Joe"), Mascara Kaboom, LLC ("Mascara Kaboom"), Third Security Senior Staff 2008 LLC ("Senior Staff 2008"), Third Security Staff 2010 LLC ("Staff 2010"), Third Security Incentive 2010 LLC ("Incentive 2010"), Third Security Senior Staff 2007 LLC ("Senior Staff 2007"), Third Security Staff 2007 LLC ("Staff 2007"), Third Security Incentive 2007 LLC ("Incentive 2007"), Third Security Staff 2009 LLC ("Staff 2009") and Third Security Incentive 2009 LLC ("Incentive 2009"). Shares held by these entities may be deemed to be 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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