A phase I and pharmacokinetic study of capecitabine in combination with epirubicin and cisplatin in patients with inoperable oesophago-gastric adenocarcinoma

Background: The purpose of this study was to evaluate the dose-limiting toxicity (DLT) and maximum tolerated dose of capecitabine when used in combination with epirubicin and cisplatin (ECC) in patients with oesophageal or gastric adenocarcinoma. Response rate, pro-g-re ss ion-free survival (PFS) and overall survival were also determined, and the effect of previous oesophago-gastric surgery or concurrent oesophago-gastric cancer on the absorption and metabolism of capecitabine was evaluated. Patients and methods: Patients with inoperable oesophago-gastric adenocarcinoma received up to six cycles of epirubicin (50 mg/m(2) i.v., 3-weekly), cisplatin (60 mg/m(2) i.v., 3-weekly) and capecitabine, the latter administered orally in an intermittent schedule (14 days treatment; 7-day rest period) at 3-weekly intervals Patients were recruited into one of four escalating dose cohorts (500, 825, 1000 and 1250 mg/m(2) bd). Dose escalation occurred after six patients had completed at least one cycle of chemotherapy at the previous dose level, with DLT assessed on the toxicity of the first cycle only. Blood sampling for pharmacokinetic analyses was performed over the first 10 h of day 1 of cycle 1. Results: Thirty-two patients, median age 63 years (range 32-76 years), ECOG performance status less than or equal to2 with locally advanced (10) or metastatic (22) disease were recruited and were evaluable for toxicity. Two of five patients experienced DLT at 1250 mg/m(2) bd with grade II stomatitis (one patient) and grade III diarrhoea with febrile neutropenia (one patient). Cumulative toxicity for all cycles (n = 140) (worst grade per patient) includes grade IV oesophagitis (one patient), grade III diarrhoea (five), grade IV neutropenia with infection (seven), grade II stomatitis (four) and grade IV thrombocytopenia (one). Of 29 patients with evaluable disease, there was one complete response and six partial responses 24% response rate [95% confidence interval (CI) 10% to 44%]}, a median PFS of 22 weeks (95% CI 17-27 weeks) and median overall survival of 34 weeks (95% CI 19-49 weeks). Capecitabine was rapidly absorbed after oral administration, with a t(max) of 1-2 h for capecitabine, DFCR (5'-deoxy-5-fluorocytidine) and DFUR (5'-deoxy-5-fluorouridine). The C-max and AUC(0-infinity) for capecitabine, DFCR and DFUR were similar to those observed in previous monotherapy studies of capecitabine taken after food. Conclusion: A dose of 1000 mg/m(2) bd of capecitabine is recommended for use on an intermittent schedule in combination with these doses and schedule of epirubicin and cisplatin This regimen is tolerable and active in oesophago-gastric adenocarcinoma. A randomised phase III comparison with ECF is justified.