Updated survival from a randomized phase III trial (MPACT) of nab-paclitaxel plus gemcitabine versus gemcitabine alone for patients (pts) with metastatic adenocarcinoma of the pancreas.
178^ Background: In the phase III MPACT trial, nab-paclitaxel (nab-P) + gemcitabine (G) was tolerable and demonstrated superiority to G alone for all efficacy endpoints in pts with metastatic pancreatic cancer (MPC). nab-P + G vs G alone met the study’s primary endpoint by demonstrating a significant improvement in overall survival (OS; median 8.5 vs 6.7 months; HR 0.72; 95% CI, 0.617 - 0.835; P < 0.001) and the secondary endpoints of progression-free survival (PFS; median 5.5 vs 3.7 months; HR 0.69; 95% CI, 0.581 - 0.821; P < 0.001) and overall response rate (ORR; 23% vs 7%; P < 0.001). The 1-year survival rates for nab-P + G vs G alone were 35% vs 22%. The OS data reported above were based on a database cutoff of September 17, 2012, at which time 80% of pts had died. Here, we report an updated OS analysis (post hoc) from MPACT. Methods: 861 pts with MPC and a Karnofsky performance status (KPS) ≥ 70 were randomized at 151 community and academic centers 1:1 to receive nab-P 125 mg/m2 + G 1000 mg/m2 on days 1, 8, and 15 of a 28-day cycle or G alone 1000 mg/m2weekly for 7 weeks followed by 1 week of rest (cycle 1) and then days 1, 8, and 15 of a 28-day cycle (cycle ≥ 2). The data for this survival analysis were collected through April 1, 2013. Results: As of the updated data cutoff, 380/431 (88%) pts in the nab-P + G arm and 394/430 (92%) pts in the G alone arm had died. OS was superior for nab-P + G vs G alone in the intent-to-treat population, and the longer follow-up allowed an estimate of the 3-year survival rates (Table). The treatment effect was consistent across all pt subgroups examined. Conclusions: This updated survival analysis revealed a sustained difference in OS over time between the 2 arms. MPACT is the first phase III study in MPC to report 3-year survival rates. These data confirm and extend the previous report of the primary endpoint and support the superior efficacy of nab-P + G over G alone. These results may encourage efforts to build upon this well tolerated backbone to further extend survival. Clinical trial information: NCT00844649. [Table: see text]