MM-398 in combination with 5-fluorouracil and leucovorin shows statistically significant improvement in overall survival, progression free survival and overall response rate in patients with post-gemcitabine metastatic pancreatic cancer Plan to file New Drug Application in 2014 Conference call to review data scheduled for 8:00 a.m. ET tomorrow, June 26 th CAMBRIDGE, Mass., June 25, 2014 (GLOBE NEWSWIRE) -- Merrimack Pharmaceuticals, Inc. (Nasdaq:MACK) today announced detailed results from NAPOLI-1, a large, randomized, three-arm Phase 3 study of MM-398, a nanoliposomal encapsulation of irinotecan, in patients with metastatic pancreatic cancer previously treated with gemcitabine-based therapy. The combination of MM-398 with 5-fluorouracil (5-FU) and leucovorin extended overall survival and significantly increased progression free survival (PFS) and overall response rate compared to the control arm of 5-FU and leucovorin alone. Top line results of NAPOLI-1 released in May showed that the combination of MM-398 with 5-FU and leucovorin achieved an overall survival of 6.1 months versus the 4.2 month survival demonstrated by the control arm of 5-FU and leucovorin alone. The primary log-rank analysis of overall survival was statistically significant (p=0.012), with a corresponding hazard ratio of 0.67. In combination with 5-FU and leucovorin, MM-398 also demonstrated a statistically significant advantage in PFS, with a median of 3.1 months compared to 1.5 months in the control arm (HR = 0.56, 95% CI [0.41-0.75], p=0.0001). The combination arm also showed a statistically significant difference in overall response rate compared to the control arm (16% and 1%, respectively, p<0.001). The most common non-hematologic grade 3 and higher adverse events in the combination arm were fatigue (14%), diarrhea (13%) and vomiting (11%). Hematologic grade 3 and higher adverse events included neutropenia, which was observed in 20% of patients as determined by objective laboratory values, and febrile neutropenia, which was observed in 2% of patients.