NEW YORK, NY, USA I March 6, 2013 I ZIOPHARM Oncology, Inc. (ZIOP), a biopharmaceutical company focused on the development and commercialization of new cancer therapies, today announced the start of a multicenter, single arm Phase 2 investigator-sponsored study of palifosfamide (ZIO-201) in patients with recurrent metastatic germ cell (testicular and ovarian) tumors who have relapsed on initial platinum-based therapy and high dose chemotherapy, or patients who are not eligible for high dose chemotherapy. The study is being conducted at the Melvin and Bren Simon Cancer Center at the Indiana University, led by Lawrence Einhorn, M.D., Distinguished Professor of the Department of Medicine, Division of Hematology/Oncology at the School of Medicine. ZIOPHARM is currently conducting Phase 3 trials of palifosfamide in first-line metastatic soft tissue sarcoma (PICASSO 3) and first-line metastatic small cell lung cancer (MATISSE). Dr. Einhorn is the lead principal investigator for the MATISSE trial. The Company expects to announce topline results from PICASSO 3 the last week of this month.

"While treatments for germ cell cancers are often effective, and five-year survival is high, there remains a population for whom relapse or a lack of tolerability lead to poor prognosis," said Dr. Einhorn. "Palifosfamide is in the same molecular class as ifosfamide, an agent that has transformed the treatment of testicular cancer. Our early experience in Phase 1 testing with palifosfamide in patients with resistant testicular and ovarian germ cell tumors is quite encouraging. Data from the Phase 2 study will inform us of how best to advance the use of palifosfamide in these diseases."

The primary endpoint is response rate (CR+PR) of single agent palifosfamide in patients with refractory germ cell tumors. The secondary endpoints include the duration of remission, progression-free survival (PFS), overall survival (OS) and the safety profile of palifosfamide in patients with germ cell tumors. In this trial, twelve patients will be treated with palifosfamide (150 mg/m2 3 days every 3 weeks for 6 cycles) and, if at least 1 response (RR of >= 8.5%) is observed, enrollment will continue to a total of twenty patients to evaluate response rate of single agent palifosfamide. Additionally, the response rate will be assessed every cycle by RECIST v1.1 and by serum AFP and beta-hCG.

About ZIOPHARM Oncology, Inc.:

ZIOPHARM Oncology is a biopharmaceutical company focused on the development and commercialization of new cancer therapies. The Company’s clinical programs include:

Palifosfamide (ZIO-201) is a potent bi-functional DNA alkylating agent that has activity in multiple tumors by evading typical resistance pathways. Palifosfamide is in the same class as bendamustine, cyclophosphamide, and ifosfamide. Intravenous palifosfamide is currently being studied in a randomized, double-blinded, placebo-controlled Phase 3 trial (PICASSO 3) for the treatment of first-line metastatic soft tissue sarcoma and is also in a pivotal Phase 3 trial (MATISSE) for first-line metastatic small cell lung cancer. Additionally, the Company is developing an oral capsule form of palifosfamide.

Ad-RTS IL-12 is currently being tested in a Phase 2 study. Ad-RTS IL-12 uses synthetic biology to enable controlled, local delivery of therapeutic interleukin-12 (IL-12), a protein important for an immune response to cancer. ZIOPHARM’s DNA synthetic biology platform is being developed in partnership with Intrexon Corporation and employs an inducible gene-delivery system that enables controlled, local delivery of genes that produce therapeutic proteins to treat cancer. This is achieved by placing IL-12 under the control of a proprietary biological "switch" (the RheoSwitch Therapeutic System(R), RTS(R)) to turn on/off the therapeutic protein expression at the tumor site.

Indibulin (ZIO-301) is a novel, tubulin binding agent that is expected to have several potential benefits, including oral dosing, application in multi-drug resistant tumors, no neuropathy and a tolerable toxicity profile. It is currently being studied in a Phase 1/2 trial in metastatic breast cancer.

Darinaparsin (ZIO-101) is a novel mitochondrial-and hedgehog-targeted agent (organic arsenic) currently in ongoing studies with Solasia Pharma K.K.

ZIOPHARM’s operations are located in Boston, MA, and New York City. Further information about ZIOPHARM may be found at www.ziopharm.com.

SOURCE: ZIOPHARM Oncology