ZIOPHARM Reports Second-Quarter 2014 Financial Results and Reviews Recent Activities BOSTON, MA

ZIOPHARM Reports Second-Quarter 2014 Financial Results and

Reviews Recent Activities

August 7, 2014 ZIOPHARM Oncology, Inc. (Nasdaq: ZIOP) today announced financial results for the second quarter ended June 30, 2014, and provided an update on the company s product development activities.

ZIOPHARM, together with our channel partner Intrexon Corporation, continues to advance a portfolio of immuno-oncology programs, with the goal of

enabling a paradigm shift in cancer treatment, said Jonathan Lewis, M.D., Ph.D., chief executive officer of ZIOPHARM. We continue to work at a rapid pace toward elucidating the enormous potential of the transformative technology driving

this pipeline in a data-driven and efficient manner. We also look forward to a number of important, value-creating clinical, preclinical and strategic milestones over the balance of the year and beyond.

Recent Corporate Highlights

ZIOPHARM expanded the scope

of its synthetic immuno-oncology programs in collaboration with Intrexon Corporation to include chimeric antigen receptor T-cell (CAR-T) therapy. CAR-T cells represent an emerging, high value immunological therapy that can target and destroy

cancer cells displaying personalized fingerprints. ZIOPHARM will utilize Intrexon s RTS platform that has the ability to facilitate precise regulation of one or more

bioeffectors in CAR-T cells enabling physicians to control systemic effects of cell therapies with an appropriate dosing regimen of the oral activator ligand (veledimex), and eventually bring about improved safety and efficacy of these and related

therapeutic strategies.

ZIOPHARM amended and restated its License and Collaboration Agreement with Solasia Pharma K.K. to grant Solasia an exclusive

worldwide license to develop and commercialize darinaparsin (Zinapar or ZIO-101), in all indications for human use. Under terms of the new agreement, ZIOPHARM could receive up to $72.2 million in development and sales-based milestones and a

royalty on net sales of darinaparsin. Solasia will be solely responsible for all costs related to the development, manufacturing and commercialization of darinaparsin.

Second-Quarter 2014 Financial Results

About ZIOPHARM Oncology, Inc.:

ZIOPHARM Oncology is a

Boston, Massachusetts-based biotechnology company employing novel gene expression and control technology to deliver DNA for the treatment of cancer. ZIOPHARM s technology platform employs Intrexon Corporation s RheoSwitch Therapeutic

System technology to turn on and off, and precisely modulate, gene expression at the cancer site in order to improve the therapeutic index. This technology is currently being evaluated in Phase 2 clinical studies of the immune system cytokine

interleukin-12 for the treatment of breast cancer and advanced melanoma. The Company s synthetic immuno-oncology programs in collaboration with Intrexon also include chimeric antigen receptor T-cell (CAR-T) approaches.

Forward-Looking Safe-Harbor Statement:

release contains certain forward-looking information about ZIOPHARM Oncology, Inc. that is intended to be covered by the safe harbor for forward-looking statements provided by the Private Securities Litigation Reform Act of 1995, as

amended. Forward-looking statements are statements that are not historical facts. Words such as expect(s), feel(s), believe(s), will, may, anticipate(s) and similar expressions

are intended to identify forward-looking statements. These statements include, but are not limited to, statements regarding our ability to successfully develop and commercialize our therapeutic products; our ability to expand our long-term

business opportunities; financial projections and estimates and their underlying assumptions; and future performance. All of such statements are subject to certain risks and uncertainties, many

of which are difficult to predict and generally beyond the control of the company, that could cause actual results to differ materially from those expressed in, or implied or projected by, the forward-looking information and statements. These risks

and uncertainties include, but are not limited to: whether Ad-RTS-IL-12, , our small molecule programs, or any of our other therapeutic discovery efforts will advance further in the clinical trials process and whether and when, if at all, they will

receive final approval from the U.S. Food and Drug Administration or equivalent foreign regulatory agencies and for which indications; whether Ad-RTS-IL-12, or our small molecule products will be successfully marketed if approved; whether any of our

other therapeutic product discovery and development efforts will be successful; our ability to achieve the results contemplated by our collaboration agreements; the strength and enforceability of our intellectual property rights; competition from

other pharmaceutical and biotechnology companies; the development of, and our ability to take advantage of, the market for our therapeutic products; our ability to raise additional capital to fund our operations on terms acceptable to us; general

economic conditions; and the other risk factors contained in our periodic and interim SEC reports filed from time to time with the Securities and Exchange Commission, including but not limited to, our Annual Report on Form 10-K for the fiscal year

ended December 31, 2013 and our Quarterly Report on Form 10-Q for the quarter ended June 30, 2014. Readers are cautioned not to place undue reliance on these forward-looking statements that speak only as of the date hereof, and we do not

undertake any obligation to revise and disseminate forward-looking statements to reflect events or circumstances after the date hereof, or to reflect the occurrence of or non-occurrence of any events.

RheoSwitch Therapeutic System (RTS ) technology is a registered trademark of Intrexon Corporation.

ZIOPHARM Oncology, Inc.

Condensed Statements of Operations

(in thousands except share and per share data)

ZIOPHARM Oncology, Inc.

Lori Ann Cafarella-Occhiogrosso