EWING, NJ, UsA I May 27, 2014 I Celator Pharmaceuticals, Inc. (CPXX), announced the publication of the Phase 2 study evaluating CPX-351 in newly diagnosed older patients with acute myeloid leukemia (AML) in Blood, the official journal of the American Society of Hematology. The study manuscript entitled “Phase 2 trial of CPX-351, a fixed 5:1 molar ratio of cytarabine/daunorubicin, vs cytarabine/daunorubicin in older adults with untreated AML” appears in the May 22, 2014 issue.

These data, along with results from the Phase 2 study of CPX-351 in patients with AML in first relapse, support Celator’s currently-enrolling Phase 3 study of CPX-351 as a first-line therapy in older patients with high-risk (secondary) AML, which is being conducted in partnership with The Leukemia & Lymphoma Society(R).

“Acute myeloid leukemia is an aggressive blood cancer with a high unmet need, particularly in older patients,” said Jeffrey Lancet M.D., Lead Investigator and Section Chief of Leukemia at the H. Lee Moffitt Cancer Center and Research Institute. “AML patients treated with CPX-351 had a higher likelihood of remission, without evidence of increased early mortality, than patients treated with standard chemotherapy. In addition, CPX-351 led to longer survival in the large subset of patients whose AML arose out of a previously diagnosed hematologic disorder or a history of prior cytotoxic treatment, commonly referred to as secondary AML.”

This randomized, controlled, Phase 2 study evaluated 126 patients, aged 60-75 years, from 18 clinical centers in the U.S. and Canada, with newly diagnosed, pathologically confirmed AML. Patients were randomized 2:1 to receive first-line CPX-351 (100 u/m2; days 1, 3, and 5 by 90 minute infusion) or the 7+3 regimen (cytarabine 100 mg/m2/day by continuous infusion for 7 days and daunorubicin 60 mg/m2 on days 1, 2, and 3). The primary endpoint for the study was complete response (CR + CRi) and secondary endpoints included CR+CRi duration, event-free survival and overall survival.

Results showed that CPX-351 treatment was associated with higher complete response rate (66.7% vs. 51.2%; P = 0.07), prolonged event-free survival (median 6.5 vs. 2.0 months) and overall survival (median 14.7 vs. 12.9 months). Ten patients with persistent AML after treatment with 7+3 crossed over to receive CPX-351 as salvage therapy with four achieving response (3 CR + 1 CRi). All four responders survived more than one year and this potentially confounds interpretation of the overall survival data.

A planned analysis of secondary AML patients (patients with a prior antecedent hematologic disorder or history of prior cytotoxic treatment) showed an improved response rate (57.6% vs 31.6%, P=0.06), prolonged event-free survival (median 4.5 vs. 1.3 months, HR=0.59, P=0.08) as well as overall survival (median 12.1 vs. 6.1 months, HR=0.46, P=0.01). The overall survival benefit in this population was statistically significant.

Treatment with CPX-351 was associated with well-characterized and manageable adverse events. Recovery from cytopenias was longer following CPX-351 (median days to ANC >=1000: 36 vs. 32; Platelets >100K: 37 vs. 28) with more grade 3-4 infections but without an increase in infection-related deaths (3.5% vs. 7.3%) or 60-day mortality (4.7% vs. 14.6%), indicating acceptable safety.

“We are very pleased with the results and insights this study offered,” said Arthur C. Louie, Chief Medical Officer of Celator. “These data suggest an enhanced clinical benefit of CPX-351 over the current standard of care, known as the 7+3 regimen, and we hope to further validate these findings with our Phase 3 study, with initial data expected in the second quarter of 2015.”

About Celator Pharmaceuticals, Inc.

Celator Pharmaceuticals, Inc., with locations in Ewing, N.J., and Vancouver, B.C., is a pharmaceutical company developing new and more effective therapies to treat cancer. CombiPlex(R), the company’s proprietary drug ratio technology platform, represents a novel approach that identifies molar ratios of drugs that will deliver a synergistic benefit, and locks the desired ratio in a nano-scale drug delivery vehicle that maintains the ratio in patients with the goal of improving clinical outcomes. The company pipeline includes two clinical stage products, CPX-351 (a liposomal formulation of cytarabine:daunorubicin) for the treatment of acute myeloid leukemia and CPX-1 (a liposomal formulation of irinotecan:floxuridine) for the treatment of colorectal cancer; and preclinical stage product candidates, including CPX-571 (a liposomal formulation of irinotecan:cisplatin), and the hydrophobic docetaxel prodrug nanoparticle (HDPN) formulation being studied by the National Cancer Institute’s Nanotechnology Characterization Laboratory. For more information, please visit the company’s website at www.celatorpharma.com. Information on ongoing trials is available at www.clinicaltrials.gov.

SOURCE: Celator Pharmaceuticals