CAMBRIDGE, Mass., Aug. 22, 2013 (GLOBE NEWSWIRE) -- Merrimack Pharmaceuticals, Inc. (Nasdaq:MACK) announced today that the British Journal of Cancer has published the paper "A Multinational Phase 2 Study of Nanoliposomal Irinotecan Sucrosofate (PEP02, MM-398) for Patients with Gemcitabine-Refractory Metastatic Pancreatic Cancer" in its latest issue (Volume 109, Issue 4). The Phase 2 study evaluated MM-398 (liposomal irinotecan sucrosulfate) monotherapy in patients with metastatic pancreatic cancer previously treated with gemcitabine-based therapy. A large, controlled Phase 3 study, NAPOLI-1 (NAnoliPOsomaL Irinotecan), evaluating this agent alone and in combination is underway in this patient population, and is expected to complete enrollment in the third quarter of 2013. The Phase 2 single-arm study met its primary endpoint with 75% of patients surviving at least 3 months, including 25% reaching the 1-year mark. In this study, median overall survival was 5.2 months, and 50% of patients showed evidence of disease control. The most common severe adverse events included neutropenia, abdominal pain, asthenia and diarrhea. "We are pleased that this study, which suggests promising results against a difficult-to-treat cancer, has been published in the respected peer-reviewed British Journal of Cancer," said Eliel Bayever, M.D., Vice President and Medical Director of MM-398. "This study laid the groundwork for our subsequent, ongoing phase 3 study of nanoliposomal irinotecan sucrosofate in the same patient population." About NAPOLI-1 NAPOLI-1 is a global, randomized, open label Phase 3 trial testing MM-398 as a monotherapy and MM-398 in combination with 5-FU/LV compared with the shared control arm of 5-FU/LV. The study was designed to enroll approximately 405 patients at over 100 sites in North America, South America, Europe, Asia and Australia. The Global Principal Investigator is Daniel von Hoff, M.D., F.A.C.P. of TGen, University of Arizona, Mayo Clinic and Scottsdale Healthcare. There is no approved treatment for patients with metastatic pancreatic cancer after gemcitabine has failed, nor is there a clear consensus on the standard of care in this patient group. Limited data suggest that without effective therapy, these patients are expected to live only a few months once they have progressed on first line therapy. Metastatic pancreatic cancer is almost uniformly fatal, with a 73 percent death rate within one year of diagnosis (American Cancer Society) and a 5-year overall survival rate of approximately six percent in the United States (National Cancer Institute).