Safety and Efficacy of Single-day GemOx Regimen in Patients with Pancreatobiliary Cancer: a Single Institution Experience

Background: GemOx (gemcitabine 1000 mg/m(2) > 100 min on day 1 and oxaliplatin 100 mg/m(2) on day 2 every 2 weeks) achieved a response rate of 26.8%, improved progression-free survival (PFS) but failed to demonstrate a benefit in overall survival (OS) compared with gemcitabine in pancreatic cancer. This regimen has regained attention after recent pooled- and meta-analysis suggested a survival benefit of gemcitabine-platinum doublets over gemcitabine. However, GemOx is associated with inconvenience to patients, early cumulative dose developing neuropathy and thrombocytopenia. In addition, fixed dose rate of gemcitabine showed no benefit > 30 min infusion schedule in the ECOG6201 study. Pharmacokinetic profiles of both drugs did not show statistically significant difference regardless of the order of administration.

Patients And Methods: In order to create a more convenient and equally effective regimen, we conducted a retrospective study to evaluate the efficacy and safety of single-day modified GemOx (S-GemOx, gemcitabine 1000 mg/m(2) > 30 min and oxaliplatin 85 mg/m(2) > 2 h on day 1 every 2 weeks) in patients with pancreatic and biliary cancers.

Results: In all, 34 patients (median age 60 years, male/female: 17/17) received S-GemOx including locally advanced or metastatic pancreatic cancer (26) and biliary duct carcinoma (8). Median treatment was six cycles with duration of 12 weeks (range (r): 2 - 56). Median cumulative dose of oxaliplatin was 517.5 mg/m(2) (r: 85 - 2380). A total of 27 of 34 patients were evaluated for efficacy after initial staging: 1 (3.7%) complete response (CR), 4 (14.8%) partial response (PR), 18 (66.7%) stable disease and 4 (14.8%) progression of disease. Overall response rate (CR + PR) was 18.5%. Median PFS and OS were 7 and 11.6 months, respectively. All patients were assessed for toxicities. Grade 3/4 hematological toxicities include anemia (8%), neutropenia (11%), thrombocytopenia (5%), nausea/vomiting (3%), diarrhea (3%), hypersensitivity reaction (14%) and neuropathy (3%). No deaths occurred due to therapy.

Conclusions: S-GemOx regimen provides convenient schedule, toxicities appear to be comparable with GemOx. The incidence of neuropathy (3 vs 19.1%) and thrombocytopenia (5 vs 14%) are substantially lower compared with GemOx. Prospective studies of S-GemOx in a large patient population are warranted.