A phase I, dose-finding study of sunitinib combined with cisplatin and 5-fluorouracil in patients with advanced gastric cancer.

Background This phase I, open-label, dose-escalation study examined the safety, maximum tolerated dose (MTD), and pharmacokinetics of sunitinib plus chemotherapy in patients with advanced gastric cancer. Patients and methods Sunitinib (25 or 37.5 mg/day, Schedule 2/1: 2 weeks on treatment/1 week off) plus chemotherapy (fixed starting doses of cisplatin 80 mg/m(2) and 5-fluorouracil [5-FU] 4,000 mg/m(2)) was administered to patients with advanced gastric cancer who had not received prior therapy for metastatic disease. Results Thirty-four patients were enrolled and received sunitinib 25 mg/day (n = 24) or 37.5 mg/day (n = 10) plus chemotherapy. No dose-limiting toxicity (DLT) was reported in the sunitinib 37.5 mg cohort. However, repeated patterns of myelosuppression beyond the first cycle led to investigation of sunitinib 25 mg/day. This was the MTD, and one DLT (grade 3 mucosal inflammation) was reported. The combination had an acceptable adverse event profile; generally of grade 1/2. There was no evidence of a pharmacokinetic drug-drug interaction between sunitinib and 5-FU. Six patients (26 %) receiving the MTD had a partial response and eight patients experienced stable disease ≥3 months. Conclusions Sunitinib plus cisplatin 80 mg/m(2) and 5-FU 4,000 mg/m(2) were combinable and adverse events were manageable. The MTD of sunitinib was established as 25 mg/day on Schedule 2/1.