Background: We have already reported on fixed-dose-rate gemcitabine (FDR-Gem) in advanced, inoperable pancreatic ductal adenocarcinoma (PDAC) and biliary tract cancer (BTC) in the context of a formal phase II study; building on that experience, we have now expanded the study to reach a cumulative accrual of 106 patients.
Methods: One hundred six patients (PDAC/BTC, 75/31) were treated with weekly FDR-Gem (1,000 mg/m(2) infused at 10 mg/m(2) per minute). Patient characteristics included: male-to-female ratio, 0.83; median age, 63 years (range, 28-82); metastatic disease in 66% of patients; and an Eastern Cooperative Oncology Group performance status (ECOG PS) score of 0-1 in 81% of patients.
Results: The median and total number of treatment weeks delivered were 8 (range, 2-22) and 1,154, respectively. Thirteen percent of patients achieved an objective response, 42% experienced a positive clinical benefit response, and 54% achieved a >50% reduction in serum cancer antigen (CA)19.9 levels. The median progression-free survival (PFS) and overall survival (OS) times for the entire population were 4.4 months (95% confidence interval [CI], 3.5-5.1 months) and 7.7 months (95% CI, 6.3-8.8 months), respectively, with 20% of patients alive at 1 year. On multivariate analysis, a CA19.9 reduction >50% and baseline ECOG PS score of 0 were the only independent predictors of PFS and OS, respectively. Treatment was well tolerated, with grade 3-4 neutropenia in 47 of 1,154 treatment weeks (4.1%), and grade 3 anemia and thrombocytopenia in 8 of 1,154 (0.7%) and 16 of 1,154 (1.4%) treatment weeks, respectively.
Conclusions: Currently available evidence, including this updated analysis, supports the use of FDR-Gem as a first-line option in advanced PDAC, and possibly in BTC, patients and prompts the continued evaluation of this approach in combination regimens.