A phase III trial of pemetrexed plus gemcitabine versus gemcitabine in patients with unresectable or metastatic pancreatic cancer

Background: This randomized phase III study compared the overall survival (OS) of pemetrexed plus gemcitabine (PG) versus standard gemcitabine (G) in patients with advanced pancreatic cancer. Patients and methods: Patients with unresectable locally advanced or metastatic pancreatic cancer and no prior systemic therapy (including 5-fluorouracil as a radiosensitizer) were randomized to receive either 1250 mg/m² gemcitabine on days 1 and 8 plus pemetrexed 500 mg/m² after gemcitabine on day 8 (PG arm) of each 21-day cycle, or gemcitabine 1000 mg/m² on days 1, 8 and 15 of each 28-day cycle (G arm). Results: Five hundred and sixty-five patients with well-balanced baseline characteristics were randomly assigned (283 PG, 282 G). OS was not improved on the PG arm (6.2 months) compared with the G arm (6.3 months) (P = 0.8477). Progression-free survival (3.9 versus 3.3 months; P = 0.1109) and time to treatment failure (3 versus 2.2 months; P = 0.2680) results were similar. Tumor response rate (14.8% versus 7.1%; P = 0.004) was significantly better on the PG arm. Grade 3 or 4 neutropenia (45.1% versus 12.8%), thrombocytopenia (17.9% versus 6.2%), anemia (13.9% versus 2.9%), febrile neutropenia (9.9% versus 0.4%; all P<0.001) and fatigue (15% versus 6.6%; P = 0.002) were significantly more common on the PG arm. Four treatment-related deaths occurred on the PG arm and none in the G arm. Conclusions: Pemetrexed plus gemcitabine therapy did not improve OS. Single-agent gemcitabine remains the standard of care for advanced pancreatic cancer.