ZIOPHARM Oncology, Inc. announced that the United States Food & Drug Administration (FDA) has granted Orphan Drug Designation to darinaparsin (Zinapar or ZIO-101) for the treatment of peripheral T-cell Lymphoma (PTCL). The United States Orphan Drug Act of 1983 was created to provide incentives for companies to develop and market treatments for diseases or conditions affecting fewer than 200,000 people in the United States. The Orphan Drug designation provides eligibility for a seven-year period of market exclusivity in the United States after product approval, an accelerated review process, accelerated approval where appropriate, grant funding, tax benefits and an exemption from user fees.

"Peripheral T-cell lymphomas represent a distinct subgroup of aggressive lymphomas that have been ignored in most lymphoma studies, creating a population whose treatment needs remain largely unaddressed in the front line setting," said James Armitage, MD, Professor of Internal Medicine, Division of Haematology and Oncology, University of Nebraska Medical Center. "Darinaparsin has demonstrated early signs of activity and tolerability in this population, with a mechanism of action that differentiates it from other existing therapeutic options."

ZIOPHARM reported favourable results from a phase II trial with IV-administered darinaparsin in lymphoma, particularly PTCL, at the 2009 Annual Meeting of the American Society of Clinical Oncology. The company expects to begin enrolling patients imminently in a phase I study of darinaparsin in combination with CHOP (Cyclophosphamide, Doxorubicin, Vincristine, and Prednisone), the current standard of care for front line PTLC, to confirm the tolerability of the combination. On the advice of leading haematology experts and subject to the outcome of this phase I study and further dialogue with the US Food and Drug Administration, the Company expects to move forward with a registration study of the darinaparsin and CHOP combination for the front-line treatment of PTCL in late 2011. There are currently no FDA-approved therapies for the front-line treatment of advanced PTCL, a setting where the National Comprehensive Cancer Network (NCCN) guidelines recommend the use of experimental drugs.

Peripheral T-cell Lymphoma represents a subgroup of aggressive lymphomas that develop from T-cells in different stages of maturity. According to the Lymphoma Research Foundation, PTCL accounts for approximately 10-15% of the estimated 66,000 new cases of non-Hodgkin's lymphoma diagnosed each year in the Unites States. PTCL generally affects people over the age of 60 and is diagnosed in more men than women.

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 programmes.