Japanese Patent Office issues patent for ZIOPHARM Oncology's darinaparsin

ZIOPHARM Oncology, Inc. (Nasdaq: ZIOP) today announced that the Japanese Patent Office has issued a patent, Patent No. 4,571,408, with claims covering pharmaceutical compositions, including oral formulations, of various organic arsenic compounds, including darinaparsin (Zinapar^TM or ZIO-101), and the use of these compositions and the organic arsenic compounds for the treatment of cancer, including as part of a combination therapy.

ZIOPHARM recently announced that it has received Orphan Drug Designation from the U.S. Food and Drug Administration (FDA) for darinaparsin in the treatment of peripheral T-cell Lymphoma (PTCL). Darinaparsin demonstrated favorable results in a Phase II trial in lymphoma, particularly PTCL. 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 PTCL, to confirm the tolerability of the combination. Subject to the outcome of this study and further dialogue with the FDA, 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. ZIOPHARM has also recently reinitiated a Phase I study of oral darinaparsin in advanced solid tumors.