ZIOPHARM RECEIVES IMPORTANT PALIFOSFAMIDE U.S. PATENT ALLOWANCE -- Additional Patent Issuances for Darinaparsin and Indibulin -- New York, NY

RECEIVES IMPORTANT PALIFOSFAMIDE U.S. PATENT ALLOWANCE

Additional Patent Issuances for Darinaparsin and Indibulin --

New York, NY - January 26,

2010 - ZIOPHARM Oncology, Inc. (Nasdaq: ZIOP) announced today that it has

received a Notice of Allowance from the U.S. Patent and Trademark Office

for Application Serial No. 11/257,766 entitled "Salts of

Isophosphoramide mustard and analogs thereof as anti-tumor agents" with claims

directed to compounds, pharmaceutical compositions, and lyophilisates. These

claims cover the Company's proprietary palifosfamide composition (ZIO-201 or

Company has recently reported positive randomized Phase II sarcoma interim data

for intravenous palifosfamide at the Annual Meeting of the Connective Tissue

Oncology Society (CTOS) on November 6, 2009 and expects, following U.S. Food and

Drug Administration (FDA) review, to initiate a registration trial the first

has also recently been granted United States Patent No. 7,619,000 covering the

oral administration of various organic arsenic compounds, including

darinaparsin, for the treatment of cancer. Darinaparsin (ZIO-101 or ZinaparTM) is a novel

mitochondrial-targeted agent having been studied intravenously in Phase II for

the treatment of lymphoma while the oral form continues in Phase I study for

both hematological malignancies and solid tumors. The Company also expects to

initiate a registration trial for darinaparsin in peripheral T-cell lymphoma

following FDA review.

ZIOPHARM has been granted Patent No. 2,326,833 by the Canadian Intellectual

Property office covering certain N-substituted indole-3-glyoxylamides, including

indibulin, for use as an antitumor agent. Indibulin (ZIO-301 or ZybulinTM) is the

Company's novel oral microtubule inhibitor being developed for the treatment of

breast cancer sub-types and is expected to enter Phase I study in the first

quarter of this year in collaboration with the Memorial

Sloan-Kettering team and using a novel biologically- and mathematically-driven

schedule of administration developed preclinically by Dr. Larry

this notice of allowance for palifosfamide, we now have established a U.S.

patent position for all three of our product candidates," said Jonathan Lewis,

MD, PhD, Chief Executive Officer of ZIOPHARM. "With the additional

issuances for darinaparsin and indidibulin, we continue to add to our patent

estates, and will continue doing so for all three programs."

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.

anti-mitochondrial (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.

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.

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

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, 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. The Company assumes no

obligation to update these forward-looking statements, except as required by

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