ZIOPHARM REPORTS FIRST QUARTER FINANCIAL RESULTS -- Decreased Cash Burn from Operations, Continued Clinical Progress

REPORTS FIRST QUARTER FINANCIAL RESULTS

Decreased Cash Burn from Operations, Continued Clinical Progress --

NEW YORK, NY - April 30, 2010

- ZIOPHARM Oncology, Inc. (Nasdaq: ZIOP), a biopharmaceutical company that is

seeking to develop and commercialize a diverse, risk sensitive portfolio of

in-licensed cancer drugs addressing unmet medical needs, today reported its

financial results for the three months ended March 31, 2010 and updated the

Company's continued progress with its clinical programs.

first quarter of 2010, the Company's cash burn from operations was $3.8 million,

a decrease of $0.8 million from $4.6 million for the same period for

2009. The spending decrease represents a continued focus of resources

as well as tight management of operating expenses. The Company ended the March

2010 quarter with cash of approximately $45.0 million. The Company

expects its existing cash resources to support operations early into the first

quarter of 2012, although this expectation could change based on, among other

things, the scope and timing for the Company's registration trial for

loss from operations for the first quarter of 2010 was $4.6 million, or $(0.11)

per share, compared with a net loss from operations for the first quarter of

2009 of $3.3 million, or $(0.16) per share. In the first quarter of

2010, there was a $13.1 million non-cash charge for the change in the fair value

of warrants arising from the increase in the Company's stock price, resulting in

a total net loss for the first quarter of $17.7 million, or $(0.44) per share,

compared with a net loss for the first quarter of 2009 of $3.3 million, or

$(0.16) per share. The warrant charge relates to fair value

accounting which requires the warrants to be marked to market under accounting

principles generally accepted in the United States.

and development expenses in the first quarter of 2010 increased $0.3 million

while General and administrative expenses increased by $0.9 million. The

increased general and administrative activity during the first three months of

2010 was related to administrative support in preparation for new clinical

studies not yet initiated.

for all three of the Company's clinical-stage compounds continue to advance.

Palifosfamide (ZymafosTM or

ZIO-201) has been recognized with acceptance for presentation at the American

Society for Clinical Oncology (ASCO) Annual Meeting in June. It has also been

selected to be included in the 2010 Best of ASCO . The

Best of ASCO program

features selected important abstracts that highlight the latest scientific

findings and practice-changing advances in cancer prevention and treatment,

allowing faculty members to provide a clinical context for this new scientific

information. Meetings are conducted in both Boston and San Francisco as well as

in many international cities. The Company expects to initiate a worldwide

palifosfamide Phase III registration trial as early as the first half of this

during the first quarter, the Company initiated a Phase I/II study of indibulin

ZIO-301) at Memorial Sloan-Kettering Cancer Center for the novel, mathematically

- determined administration of indibulin in the treatment of metastatic breast

cancer. With regard to darinaparsin (ZinaparTM, or

ZIO-101), the Company recently presented preclinical

2010 AACR Annual Meeting and the Phase I clinical studies of the oral form of

the drug are continuing while the Company moves to a potential pathway for

regulatory approval of the intravenous form in peripheral T-cell

ZIOPHARM Oncology, Inc.:

biopharmaceutical company engaged in the development and commercialization of a

diverse portfolio of cancer drugs. The Company is currently focused on three

ZIO-201) references a novel composition (tris formulation) that comprises the

functional active metabolite of ifosfamide, a standard of care for treating

sarcoma, lymphoma, testicular, and other cancers. Palifosfamide delivers

only the cancer fighting component of ifosfamide. It is expected to overcome the

resistance seen with ifosfamide and cyclophosphamide, two of the most commonly

used DNA-alkylating drugs used to treat cancers. Palifosfamide does not have the

toxic metabolites of ifosfamide that cause the debilitating side effects of

"fuzzy brain" (encephalopathy) and severe bladder inflammation. It

may also have other advantages. Intravenous palifosfamide is

currently in a randomized Phase II trial to treat unresectable or metastatic

soft tissue sarcoma in the front- and second-line setting with the Company

having reported interim positive results in late 2009; a registration trial in

the same setting is expected to initiate following U.S. Food and Drug

Administration (FDA) review in the first half of this year. An oral form of

palifosfamide has been developed preclinically to the investigational new drug

mitochondrial-targeted agent (organic arsenic) being developed for the treatment

of various hematologic and solid cancers. Preclinical and clinical studies to

date have demonstrated that darinaparsin is considerably less toxic than

inorganic arsenic, particularly with regard to cardiac toxicity. The Company has

reported favorable results from a Phase II trial with IV-administered

darinaparsin in lymphoma, particularly peripheral T-cell lymphoma ("PTCL"), at

the American Society of Clinical Oncology (ASCO) in May of 2009 which would

serve as the basis for ongoing clinical study in PTCL following regulatory

review and available financial resources. Phase I trials with the oral form are

ongoing in both hematological malignancies and solid tumors.

novel, oral tubulin binding agent that targets both mitosis and cancer cell

migration. In addition, indibulin is expected to have several potential

benefits, including oral dosing, application in multi-drug resistant tumors, no

neuropathy and minimal overall toxicity. In multiple Phase I trials

in cancer patients, oral indibulin has been administered both as a single agent

and in combination with favorable activity and a promising safety profile that

does not include the neurotoxicity seen with all of the other classes of tubulin

binding agents. Most recently, results of oral indibulin in combination with

oral capecitabine (Xeloda ) were

presented at last year's American Society of Clinical Oncology (ASCO) along with

the preclinical findings of a novel dosing schedule conducted under the

direction of Dr. Larry Norton; employing this dosage schedule, the Company has

initiated a Phase I study in breast cancer patients with the Breast Cancer

Medicine Service at Memorial Sloan-Kettering Cancer Center.

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.

Safe Harbor Statement:

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