Phase I/II study of nab-paclitaxel plus gemcitabine for chemotherapy-naive Japanese patients with metastatic pancreatic cancer.

PURPOSE: Efficacy and safety of nab-paclitaxel plus gemcitabine have not been clarified in Japanese patients with metastatic pancreatic cancer. No pharmacokinetic profile of co-administration of nab-paclitaxel and gemcitabine has been reported. We conducted a phase I/II study of the efficacy, safety, and pharmacokinetics in Japanese patients with metastatic pancreatic cancer.

METHODS: The patients were administered 125 mg/m(2) nab-paclitaxel followed by 1000 mg/m(2) gemcitabine on day 1, 8, and 15 every 4 weeks. Treatment was continued until disease progression, unacceptable adverse events, or withdrawal of consent, whichever occurred first. The primary endpoints were tolerability in phase I and overall response rate according to RECIST in phase II.

RESULTS: A total of 34 patients were enrolled. At the time of 1-year follow-up analysis since the last patient enrollment, the objective response rate by independent review committee was 58.8% (20 of 34 patients; 95% confidence interval [CI], 40.7-75.4%). The median progression-free survival and median overall survival were 6.5 months (95% CI, 5.1-8.3) and 13.5 months (95% CI, 10.6--not reached), respectively. Main adverse drug reactions of grade 3 or higher were neutropenia (70.6%), leukopenia (55.9%), anemia (14.7%), lymphocytopenia (14.7%), thrombocytopenia (14.7%), and peripheral sensory neuropathy (11.8%). There were no treatment-related deaths and no marked differences in pharmacokinetics of combined paclitaxel and gemcitabine in historical comparison between co-administration and monotherapies.

CONCLUSIONS: Nab-paclitaxel plus gemcitabine regimen showed highly promising efficacy with manageable safety profile under careful observation and with appropriate supportive care in Japanese patients with metastatic pancreatic cancer.

CLINICAL TRIAL NUMBER: JapicCTI-121987.