ZIOPHARM Oncology Appoints Brian L. Hamilton, M.D., Ph.D., as Senior Vice President, Clinical Operations

ZIOPHARM Oncology, Inc. (Nasdaq: ZIOP) announced today that it has appointed Brian L. Hamilton, M.D., Ph.D., as Senior Vice President of Clinical Operations. In this newly created position, Dr. Hamilton will report to Chief Executive Officer and Chief Medical Officer Jonathan Lewis, M.D., Ph.D., and will be responsible for guiding the Company’s clinical programs, including the PICASSO 3 trial, an international, randomized, double-blinded, placebo-controlled trial of palifosfamide and doxorubicin in patients with metastatic soft tissue sarcoma. The Company also announced that J. Kris Piper has been appointed Vice President, Clinical Regulatory, Quality and Project Management. Mr. Piper will report to Bob Morgan, J.D., Senior Vice President, Regulatory Affairs, Quality, and Pharmaceutical Development. Both executives will be located in the Company’s operational office in Boston, MA.

"We are pleased to welcome Brian and Kris to the team at an exciting time for ZIOPHARM,” stated Dr. Lewis. "Brian’s return to our senior management team comes at a time when ZIOPHARM is embarking on an extensive, multi-faceted, late-stage development effort with three high-value therapies. The combined insights and experience of these two individuals, which includes extensive expertise in clinical strategy, clinical operations and regulatory affairs, will contribute to the growth and positive momentum we have built at ZIOPHARM and will be critical as we advance our product candidates to market.”

Dr. Hamilton is rejoining ZIOPHARM Oncology, having served as the Company’s Acting Vice President of Medical Affairs from October 2008 until March 2009. He has an extensive academic background as well as 16 years of experience in industry. Prior to his return to the Company, Dr. Hamilton served as a Senior Vice President and Chief Medical Officer at Soligenix, Inc. He also served as Senior Director of Clinical Research with Wyeth Research and was Vice President for Clinical and Regulatory Affairs at Merrimack Pharmaceuticals. Dr. Hamilton had significant involvement in clinical research programs at BioVex, Biopharm Solutions, and AstraZeneca, US. Dr. Hamilton’s academic career at the University of Washington and the University of Miami focused on the use of bone marrow transplantation to treat children with congenital immune deficiency. He received his M.D. and Ph.D. from the University of Washington, with post-graduate training in Pediatrics, Allergy, Immunology and Oncology.

Mr. Piper has over 30 years of industry experience in new drug development. He has successfully participated in the submission of more than 35 INDs/CTAs and the approval for more than 20 NDAs/BLAs. Prior to joining ZIOPHARM, Mr. Piper was Vice President at Xanthus Pharmaceuticals (acquired by Antisoma in 2008), where he oversaw regulatory affairs, quality and clinical operations. Mr. Piper has also held senior positions at Bracco Diagnostics, Berlex Laboratories, Diatide, Mallinckrodt Medical, American Hospital Supply Corp., G.D. Searle and Bayer Healthcare. Mr. Piper received his B.S. in Animal Science and M.S. in Physiology from the University of California at Davis.

About ZIOPHARM Oncology, Inc.:

ZIOPHARM Oncology is a biopharmaceutical company engaged in the development and commercialization of a diverse portfolio of cancer drugs. The Company is currently focused on three clinical programs.

Palifosfamide (Zymafos^TM or ZIO-201) is a novel DNA cross-linker in class with bendamustine, ifosfamide, and cyclophosphamide. ZIOPHARM is currently enrolling patients in a randomized, double-blinded, placebo-controlled Phase III trial with palifosfamide administered intravenously for the treatment of metastatic soft tissue sarcoma in the front-line setting. The Company expects to initiate additional studies in the near-term, including a Phase I intravenous study of palifosfamide in combination with standard of care addressing small cell lung cancer and a Phase I study of oral palifosfamide.

Darinaparsin (ZinaparTM or ZIO-101) is a novel mitochondrial-targeted agent (organic arsenic) being developed intravenously for the treatment of peripheral T-cell lymphoma with a pivotal study expected to begin in late 2011. An oral form is in a Phase I trial in solid tumors.

Indibulin (ZybulinTM or ZIO-301) is a novel, oral tubulin binding agent that is expected to have several potential benefits including oral dosing, application in multi-drug resistant tumors, no neuropathy and minimal overall toxicity. It is currently being studied in Phase I/II in metastatic breast cancer.

ZIOPHARM's operations are located in Boston, MA with an executive office in New York City. Further information about ZIOPHARM may be found at www.ziopharm.com.

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Forward-Looking Safe Harbor Statement:

This press release contains forward-looking statements for ZIOPHARM Oncology, Inc. that involve risks and uncertainties that could cause the Company's actual results to differ materially from the anticipated results and expectations expressed in these forward-looking statements. These statements are based on current expectations, forecasts and assumptions that are subject to risks and uncertainties, which could cause actual outcomes and results to differ materially from these statements. Among other things, there can be no assurance that any of the Company's development efforts relating to its product candidates will be successful, or such product candidates will be successfully commercialized. Other risks that affect forward-looking information contained in this press release include the possibility of being unable to obtain regulatory approval of the Company's product candidates, the risk that the results of clinical trials may not support the Company's claims, the risk that pre-clinical or clinical trials will proceed on schedules that are consistent with the Company's current expectations or at all, risks related to the Company's ability to protect its intellectual property and its reliance on third parties to develop its product candidates, risks related to the sufficiency of existing capital reserves to fund continued operations for a particular amount of time and uncertainties regarding the Company's ability to obtain additional financing to support its operations thereafter, as well as other risks regarding the Company that are discussed under the heading "Risk Factors" in the Company's filings with the United States Securities and Exchange Commission. Forward-looking statements can be identified by the use of words such as "may," "will," "intend," " should," "could," "can," "would," "expect," "believe," "estimate," " predict," "potential," "plan," "is designed to," "target" and similar expressions. The Company assumes no obligation to update these forward-looking statements, except as required by law.