Exhibit
99.1











ZIOPHARM
REPORTS SECOND QUARTER FINANCIAL RESULTS


AND
UPDATES CLINICAL PROGRAMS







NEW YORK, NY – July 30, 2010 -
ZIOPHARM Oncology, Inc. (Nasdaq: ZIOP), a biopharmaceutical cancer company
addressing unmet medical needs, today reported its financial results for the
three months ended June 30, 2010 and provided an update on the Company’s
continued progress with its clinical programs.





For the
second quarter of 2010, the Company’s cash used in operations was $4.3 million,
an increase of $2.1 million from $2.2 million for the same period for 2009. The
spending increase is attributable to the deployment of additional resources
leading up to the July 2010 initiation of the Company’s Phase III trial of
palifosfamide in metastatic soft tissue sarcoma.  The Company ended
the June 2010 quarter with cash of approximately $73.7 million.  The
Company expects its existing cash resources to support operations into
mid-2012.





The
Company reported net loss from operations for the second quarter of 2010 of $5.1
million, or $(0.12) per basic share, compared to a net loss from operations of
$2.2 million, or $(0.10) per share in the second quarter of 2009. In the second
quarter of 2010, the Company recognized a non-cash gain of $14.1 million
attributable to the change in liability-classified warrants arising primarily
from a decrease in the Company’s stock price during the period, resulting in
total net income for the second quarter of 2010 of $9.0 million or $0.21 per
basic share ($0.19 per diluted share), compared with a net loss for the second
quarter of 2009 of $2.4 million, or $(0.11) per share. The non-cash warrant
income relates to fair value accounting which requires liability-classified
warrants to be marked-to-market under U.S. generally accepted accounting
principles.





During
the second quarter of 2010, research and development expenses increased by $1.7
million and general and administrative expenses increased by $1.2 million over
the second quarter of 2009. The increases are attributable to preliminary work
related to the palifosfamide Phase III pivotal trial as well as to new clinical
studies not yet initiated.





Clinical
Programs Update





ZIOPHARM
recently announced the initiation of its pivotal Phase III trial for
palifosfamide (ZymafosTM or
ZIO-201) in patients with front-line metastatic soft tissue sarcoma. The study,
called PICASSO 3, will enroll approximately 424 patients in up to 150 centers in
North America, Europe, South America, Australia, Israel and Korea. The Company
expects to initiate a Phase I trial of palifosfamide in a second indication,
small cell lung cancer, with Lawrence Einhorn, M.D., Lance Armstrong Professor
of Oncology at the Indiana University Simon Cancer Center, in the fourth quarter
of 2010.  This will be followed by a randomized Phase II
study.




ZIOPHARM
will also study palifosfamide in oral form in a Phase I trial that it expects to
initiate in the fourth quarter of 2010.







With
regard to darinaparsin (ZinaparTM or
ZIO-101), the Company re-initiated enrollment in a Phase I trial of its oral
formulation during the quarter and expects to initiate a Phase I trial of IV
darinaparsin used in combination  with “CHOP,” a therapeutic regimen
commonly used in the treatment of lymphomas.  The CHOP study is
intended to establish safety and tolerability of the combination for subsequent
use in a pivotal randomized trial for the front-line treatment of peripheral
T-cell lymphoma.





With
regard to indibulin (ZybulinTM or
ZIO-301), the Company continues to enroll patients in a Phase I/II study in
metastatic breast cancer which is being conducted at Memorial Sloan-Kettering
Cancer Center.  The study employs a novel, mathematically-determined
administration schedule for indibulin that was developed by Larry Norton, M.D.
Deputy Physician-in-Chief for Breast Cancer Programs at Memorial Sloan-Kettering
and Medical Director of the Evelyn H. Lauder Breast Center.





About
ZIOPHARM Oncology, Inc.:


ZIOPHARM
Oncologyis 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
(ZymafosTM or
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. ZIOPHARM is
currently enrolling patients in a randomized, double-blinded,
placebo-controlled  Phase III trial of intravenous palifosfamide used
in the treatment of metastatic soft tissue sarcoma in the front-line
setting.





Darinaparsin
(ZinaparTM or
ZIO-101)is a novel
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”),
which would serve as the basis for ongoing clinical study in PTCL following a
Phase I trial in combination with “CHOP,” a treatment regimen commonly used in
the treatment of lymphomas. A Phase I trial with the oral form is expected to
establish maximum tolerated dose.





Indibulin
(ZybulinTM or
ZIO-301)is a
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. The Company has initiated a Phase I study in breast cancer
patients with the Breast Cancer Medicine Service at Memorial Sloan-Kettering
Cancer Center using a novel dosing regimen established by Dr. Larry
Norton.











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.





ZIOP-E





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.










ZIOPHARM
      Oncology, Inc.Condensed
      Statements of Operations(in
      thousands except share and per share
data)




Three
      Months EndedJune
      30,(unaudited)2010
                                                  
                                                  
                                                  2009Research
      contract revenue
                                                  
                                                  $
                                                  -
                                                  
                                                  
                                                  $
                                                  -Operating
      expenses:Research
      and development, includingcosts
      of research contracts
                                                  
                                                  
                                                  2,222
                                                  
                                                  
                                                  
                                                  501General
      and administrative
                                                  
                                                  
                                                  2,894
                                                  
                                                  
                                                  
                                                  1,692Total
      operating expenses
                                                  
                                                  
                                                  5,116
                                                  
                                                  
                                                  
                                                  2,193Loss
      from operations
                                                  
                                                  
                                                  (5,116
                                                  )
                                                  
                                                  
                                                  (2,193
                                                  )Other
      income, net
                                                  
                                                  
                                                  13
                                                  
                                                  
                                                  
                                                  2Change
      in fair value of warrants
                                                  
                                                  
                                                  14,142
                                                  
                                                  
                                                  
                                                  (208
                                                  )Net
      income (loss)
                                                  
                                                  $
                                                  9,039
                                                  
                                                  
                                                  $
                                                  (2,399
                                                  )Net
      income (loss) per share - basic
                                                  
                                                  $
                                                  0.21
                                                  
                                                  
                                                  $
                                                  (0.11
                                                  )Net
      income (loss) per share - diluted
                                                  
                                                  $
                                                  0.19
                                                  
                                                  
                                                  $
                                                  (0.11
                                                  )Weighted
      average common shares outstanding usedto
      compute net income (loss) per share - basic
                                                  
                                                  
                                                  42,364,791
                                                  
                                                  
                                                  
                                                  21,307,297Weighted
      average common shares outstanding usedto
      compute net income (loss) per share - diluted
                                                  
                                                  
                                                  48,822,686
                                                  
                                                  
                                                  
                                                  21,307,297




ZIOPHARM
      Oncology, Inc.Balance
      Sheet Data(in
      thousands)




June
      30,
                          
                          
                          December
      31,2010
                          
                          
                          2009(unaudited)
                          
                          
                          (unaudited)Cash
      and cash equivalents
                          
                          
                          73,662
                          
                          
                          
                          48,839Working
      capital
                          
                          
                          71,636
                          
                          
                          
                          46,098Total
      assets
                          
                          
                          74,456
                          
                          
                          
                          49,736Total
      stockholders' equity
                          
                          
                          54,718
                          
                          
                          
                          28,104













Contacts:





Tyler
Cook


ZIOPHARM
Oncology, Inc.


617-259-1982


tcook@ziopharm.com





Media:


David
Pitts


Argot
Partners


212-600-1902


david@argotpartners.com