Celator Pharmaceuticals Announces Positive Induction Response Results from Phase 3 Study of CPX-351 in Patients with High-Risk Acute Myeloid Leukemia

Celator Pharmaceuticals, Inc.

today announced final induction response rate results (complete remission plus complete remission with incomplete hematologic recovery, or CR+CRi) in the Phase 3 study comparing CPX-351 (cytarabine:daunorubicin) liposome injection to the standard of care regimen, referred to as 7+3 (conventional cytarabine and daunorubicin treatment), in patients with untreated high-risk (secondary) acute myeloid leukemia (AML). The results showed that CPX-351 produced a relative improvement in induction response rate of 43.2% (47.7% for CPX-351 vs. 33.3% for the 7+3 regimen). Data on overall survival, the primary endpoint, are expected in the first quarter of 2016. However, induction response rate is a key secondary endpoint in the study and has been an important surrogate of overall survival and clinical benefit in this patient population. These data validate the induction response rates observed in the Phase 2 study, which was associated with a marked improvement in overall survival. "The results are encouraging because this is the third randomized study in which CPX-351 outperformed the control arm of cytarabine plus an anthracycline in overall response rate," said Jeffrey Lancet, M.D., Senior Member and Chief of the Leukemia/Myelodysplasia Program at Moffitt Cancer Center and lead investigator on the Phase 3 study. "With induction therapy for AML, response rate has historically served as a surrogate for overall survival, and these data suggest a clinically meaningful benefit for CPX-351 over standard chemotherapy." Gail Roboz, M.D., Associate Professor of Medicine and Director of the Leukemia Program at the Weill Medical College of Cornell University and the NewYork-Presbyterian Hospital in New York added, "The magnitude of the CR+CRi rate increase is promising and we may be one step closer to having a superior treatment option for patients with this devastating disease. The improvement in response rate portends well for a clinically meaningful survival benefit." The randomized, controlled, Phase 3 study evaluated 309 patients, aged 60-75 years, from 39 clinical centers in the U.S. and Canada, with untreated high-risk (secondary) AML. Patients were randomized 1:1 to receive either CPX-351 or the 7+3 regimen. In addition to induction response and overall survival, other important information, such as rate of morphologic leukemia-free state, best overall response, response duration, event-free survival, and early mortality, as well as pharmacoeconomic comparisons, will be assessed and available at the conclusion of the study. The Leukemia & Lymphoma Society® has partnered with Celator in the development of CPX-351. "We are very pleased with the induction response rate results. This is one of the largest trials conducted in this specific patient population, and based on the improvement seen with CPX-351, we are optimistic about the opportunity for CPX-351 to improve overall survival in this patient population," said Scott Jackson, Celator's Chief Executive Officer. "We look forward to the continued follow up of these patients. If approved, CPX-351 will be well-positioned to become the standard of care for high-risk AML patients. Further, we believe that significant opportunities exist for the additional development of CPX-351 as the backbone of treatment for AML and other blood cancers." Data on the primary endpoint of the study, overall survival, are expected in the first quarter of 2016. Additional information regarding the study is available at http://clinicaltrials.gov/show/NCT01696084.