Efficacy and safety of weekly nab-paclitaxel plus gemcitabine in Chinese patients with metastatic adenocarcinoma of the pancreas: a phase II study

BACKGROUND: This phase II bridging study assessed the safety and efficacy of nab-paclitaxel/gemcitabine (Metastatic Pancreatic Adenocarcinoma Clinical Trial [MPACT] regimen) in Chinese patients with metastatic pancreatic cancer (MPC). METHODS: This 3-part sequential study evaluated nab-paclitaxel 125 mg/m(2) plus gemcitabine 1000 mg/m(2) on days 1, 8, and 15 every 4 weeks. Part 1 evaluated safety. Part 2 evaluated efficacy using Simon’s optimal 2-stage design: if >2 responses were observed in Stage 1 (n = 28), 54 additional patients would be enrolled in Stage 2. If >9 responses were observed, the study was complete. Otherwise, nab-paclitaxel/gemcitabine would be compared with gemcitabine alone in Part 3. The primary endpoint was overall response rate (ORR). Secondary endpoints included duration of response (DOR), overall survival (OS), and safety. RESULTS: Eighty-three patients were treated. The prespecified primary endpoint was met: the independently assessed ORR in Stages 1 + 2 was 35% (95% CI, 24.8–46.2); therefore, Part 3 was not initiated. The median DOR was 8.9 months (95% CI, 6.01–8.94). The median OS and progression-free survival were 9.2 (95% CI, 7.6–11.1) and 5.5 (95% CI, 5.29–7.16) months, respectively. The 12-month OS rate was 30%. In an updated analysis, the median OS was 9.3 months and the 12-month OS rate was 32%. Longer OS was observed in patients with baseline neutrophil-to-lymphocyte ratio ≤ 5 vs > 5. The most common grade ≥ 3 adverse events were leukopenia (35%), neutropenia (34%), anemia (15%), thrombocytopenia (10%), and fatigue (13%). Grade 3 peripheral neuropathy occurred in 7% of patients (no grade 4 reported). CONCLUSIONS: The MPACT regimen of nab-paclitaxel/gemcitabine is efficacious in Chinese patients with MPC. No new safety signals were observed. TRIAL REGISTRATION: NCT02135822, May 8, 2014.