Celator Pharmaceuticals Announces Presentations of Positive Survival Analyses from CPX-351 Studies at ASCO Annual Meeting

-- CPX-351 confers significant survival advantage on AML patients in first-relapse with unfavorable risk factors compared to salvage therapy --

-- Similar survival benefit seen for CPX-351 complete response cohorts (CR and CRi) in elderly patients with newly diagnosed AML --

PRINCETON, N.J.--(BUSINESS WIRE)--Jun 5, 2012 - Celator Pharmaceuticals today announced positive survival analyses from two completed clinical trials of CPX-351 (cytarabine:daunorubicin) Liposome Injection in acute myeloid leukemia (AML). A subset analysis of data from a randomized Phase 2b study in AML patients in first-relapse showed that patients with an unfavorable risk profile had significantly improved survival after treatment with CPX-351 compared to standard salvage therapies (ASCO Abstract 6525). Results from a second randomized Phase 2b study in elderly patients with newly diagnosed AML suggested that survival in patients with CRi (complete response with incomplete recovery of neutrophils or platelets) was similar to CR (complete response with complete recovery of neutrophils and platelets) (ASCO Abstract 6601), an effect usually not seen with standard treatment. The clinical findings were presented at the American Society of Clinical Oncology (ASCO) Annual Meeting, Chicago, IL, June 1-5, 2012.

"These data are encouraging because they suggest that CPX-351 may be particularly useful in patients with poor prognostic factors whose need for new treatments is the greatest," said Scott Jackson, chief executive officer of Celator Pharmaceuticals. "Both of these studies provide a strong basis for Phase 3 pivotal trials and our ongoing efforts to bring CPX-351 to market."

CPX-351 Improves Survival After First Relapse in Unfavorable Risk Patients1

A randomized, open-label Phase 2b study treated 125 patients between the ages of 18 and 65 with first relapse AML at 35 sites in the United States, Canada, France and Poland. Patients were stratified using the European Prognostic Index (EPI) and following a 2:1 randomization, 81 patients received CPX-351 and 44, in the control arm, received a salvage regimen of the investigators' choice. Primary and secondary endpoints from this trial were reported previously.

In this subset analysis by prognostic group, a statistically significant difference was seen in overall survival (OS) in patients with unfavorable EPI risk scores with a hazard ratio = 0.55, p=0.02, and a median OS of 6.6 months following CPX-351 compared to 4.2 months in the control group.

"The benefit seen in patients with AML in first relapse is encouraging," said Stuart Goldberg, M.D., of Hackensack University Medical Center in Hackensack, NJ. "In particular, the unfavorable risk patients, a population with a poorer prognosis, demonstrated a survival advantage over salvage therapy and further studies are warranted with CPX-351."

This study was supported through a partnership between Celator and The Leukemia & Lymphoma Society®.

CPX-351 Improves Survival in Patients Achieving CR and CRi2

Another randomized, open-label Phase 2b study, comparing CPX-351 to standard of care conventional cytarabine and daunorubicin (7+3 regimen) enrolled patients between the ages of 60-75 years with newly-diagnosed AML at 18 sites in the United States and Canada. Patients were stratified as high risk (age ‰¥70 or secondary AML or ‰¥3 chromosomal abnormalities) or standard risk (all other patients).

Compared to 7+3, CPX-351 produced equivalent rates of CR (48.2% versus 48.8%) but substantial increases in the percentage of patients with CRi (17.6% versus 2.4%). With conventional cancer treatments, survival rates in patients with CRi are usually inferior to those with CR, primarily due to relapsing disease. The current analysis compared outcomes between CR and CRi patients who received CPX-351 and found no significant difference in survival between the two response cohorts (hazard ratio = 0.71, p=0.50), despite the fact that a greater proportion of CRi patients had adverse cytogenetics and secondary AML and also had less post-remission treatment. This finding, suggesting that CRi following CPX-351 treatment may confer similar survival benefit to CR with CPX-351 treatment, will need to be validated in a larger cohort of CPX-351 treated patients. Additional results from this study were previously reported.

In both studies, adverse events associated with CPX-351 treatment were well-characterized and manageable. The myelosuppressive effect of CPX-351 was greater than the control arms with slower neutrophil and platelet recovery, and adverse events were consistent with these effects.

About CPX-351

CPX-351 (cytarabine:daunorubicin) Liposome Injection represents a new approach to developing combinations of drugs in which drug molar ratios with synergistic anti-tumor activity are encapsulated in a drug delivery vehicle in order to maintain the desired ratio following administration. CPX-351 has been granted orphan drug status by both the U.S. and the European Union. CPX-351 has completed two randomized, controlled, phase 2 clinical studies for the treatment of acute myeloid leukemia (AML). One study compared CPX-351 to the standard ˜7+3” regimen of cytarabine:daunorubicin in patients 60-75 years of age with newly diagnosed AML and the other compared CPX-351 versus intensive salvage therapy in first relapse AML patients 18-65 years of age. The study in patients with first relapse AML was supported by The Leukemia & Lymphoma Society®.

About Celator Pharmaceuticals, Inc.

Celator Pharmaceuticals, Inc., with locations in Princeton, NJ, and Vancouver, BC, is a privately held pharmaceutical company developing new and more effective therapies to treat cancer. CombiPlex®, 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; a preclinical stage product, CPX-571 (a liposomal formulation of irinotecan:cisplatin); and multiple research programs, including the hydrophobic docetaxel prodrug nanoparticle (HDPN) formulation being studied by the National Cancer Institute's Nanotechnology Characterization Laboratory. Based on the applications of CombiPlex and the proprietary nanoparticle prodrug delivery platform, Celator is positioned to advance a broad pipeline of cancer therapies involving both previously approved and novel drug agents. For more information, please visit the company's website at www.celatorpharma.com. Information on ongoing trials is available at www.clinicaltrials.gov.

      1.   Goldberg SL, Cortes J, Feldman EJ, Rizzieri DA, Kantarjian HM, Limor S, et al. Initial lvage therapy in 1st relapse AML: A phase IIb study of CPX-351 vs. investigator's choice, a subset analysis by prognostic group. Poster presented at the American Society of Clinical Oncology Annual Meeting, Chicago, IL, June 1-5, 2012. ASCO Abstract #6525.
           
      2.   Lancet J, Cortes J, Kovacsovics T, Hogge D, Kolitz JE, Tallman MS, et al. A comparison of CR vs. CRi response following CPX-351 treatment of newly diagnosed AML in elderly patients. Poster presented at the American Society of Clinical Oncology Annual Meeting, Chicago, IL, June 1-5, 2012. ASCO Abstract #6601.

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or
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Posted: June 2012

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