ZIOPHARM Oncology Reports Positive Preliminary Palifosfamide Overall Survival Data From Randomized Phase 2 Study in Soft Tissue Sarcoma

ZIOPHARM Oncology, Inc. (Nasdaq: ZIOP) announced today positive preliminary overall survival data from the Company's randomized, controlled Phase 2 trial of palifosfamide plus doxorubicin vs. doxorubicin alone in patients with unresectable or metastatic soft tissue sarcoma.An analysis of the OS data conducted according to the statistical analysis plan, with greater than 70% of events occurring and follow-up of 33 months, demonstrated a meaningfully positive trend favoring the palifosfamide arm (ITT hazard ratio of 0.79 and a mITT hazard ratio of 0.78). This well-controlled trial is demonstrating longer than expected survival in a difficult to treat population. At 2-years after starting treatment, approximately 40% of subjects treated with palifosfamide are alive; 30% in the control arm treated with doxorubicin (including those who crossed-over and received subsequent palifosfamide) are alive, compared to an expected 25% based on randomized data. As planned, the study will continue to track OS events and final results are expected to be reported at a major medical conference in the second half of 2012. This analysis supports the hypothesis behind the powering of the Phase 3 trial (PICASSO 3) for both progression-free survival (PFS) for accelerated approval and OS for full approval.