ZIOPHARM Oncology, Inc. (ZIOP.OB) Reports Positive Preliminary Palifosfamide Overall Survival Data From Randomized Phase 2 Study in Soft Tissue Sarcoma:
NEW YORK, Feb. 13, 2012 (GLOBE NEWSWIRE) — ZIOPHARM Oncology, Inc. (Nasdaq:ZIOP – News), a biopharmaceutical company with small molecule and synthetic biology approaches to new cancer therapies, announced today positive preliminary overall survival (OS) data from the Company’s randomized, controlled Phase 2 trial of palifosfamide plus doxorubicin vs. doxorubicin alone (PICASSO) 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.
“These Phase 2 survival data are promising and important. The data are particularly relevant given the cross-over permitted for patients treated with doxorubicin alone. Having previously demonstrated a statistically significant PFS improvement, these positive survival data are good news for patients who have soft tissue sarcomas,” said Robert Maki, MD PhD, Professor of Medicine, Pediatrics and Orthopedics, and Sarcoma Center leader at Mount Sinai School of Medicine, New York, NY. “I look forward to the potential of these data translating to the ongoing pivotal PICASSO 3 trial, which is appropriately powered for progression-free and overall survival.”
ZIOPHARM is currently evaluating palifosfamide in an international, randomized, double-blinded, placebo-controlled Phase 3 trial in front-line metastatic soft tissue sarcoma, and completing a Phase 1 study in solid tumors, including small cell lung cancer (SCLC). Palifosfamide is entering into an adaptive Phase 3 trial in extensive SCLC expected to initiate in the second half of 2012. Additionally, an investigational new drug application has been accepted for the oral form of palifosfamide.
As presented at the 2010 Annual Meeting of the American Society of Clinical Oncology, the Phase 2 PICASSO trial randomized a total of 67 patients with 66 treated and 62 eligible for evaluation. The study was powered to show a difference in PFS between doxorubicin in combination with palifosfamide versus doxorubicin alone. An analysis of the evaluable data reported a hazard ratio of 0.39 (p=0.023). This analysis also reported RECIST response rate — for the palifosfamide arm 23%, and for the doxorubicin arm alone 9%. Safety data have been similar between the arms of the study. The most common grade 3-4 events are neutropenia and elevated creatinine; both observed with similar frequency between treatment groups. There has been no encephalopathy, hemorrhagic cystitis, nor Fanconi’s syndrome observed in the study.