Phase I/II study of gemcitabine plus vinorelbine in non-small cell lung cancer

Because gemcitabine and vinorelbine have demonstrated single-agent activity in non-small cell lung cancer (NSCLC), we conducted this phase I/II study to determine the maximum tolerated dose (MTD) and activity of these drugs combined.

Patients with inoperable or advanced NSCLC and no prior chemotherapy were treated with gemcitabine plus vinorelbine on days 1 and 8 every 21 days. The initial doses of gemcitabine 1,000 mg/m2 and vinorelbine 25 mg/m2 were escalated by 250 mg/m2 and 5 mg/m2, respectively, in separate patient cohorts until the MTD was established.

In phase I, 32 patients received a total of 115 cycles. Dose-limiting toxicities were neutropenia and hepatotoxicity, occurring at the dose level of 1,500 mg/m2 and 30 mg/m2. Thus, the MTD used for phase II was 1,250 mg/m2 and 30 mg/m2. Of 41 patients in phase II, 16 (39%) achieved objective responses (95% confidence interval [CI] 24% to 54%), with a median time to progression of 4.2 months. Overall survival was 9 months (95% CI 5.7 to 12.7 months) and the 1-year survival rate was 31%. World Health Organization (WHO) > or = grade 3 neutropenia and reversible thrombocytosis occurred in 15% and 65% of patients, respectively. Non-hematologic toxicity was mild at all dose levels. Grades 3 and 4 hepatotoxicity were reported in one patient each.

The combination of 1,250 mg/m2 gemcitabine and 30 mg/m2 vinorelbine on days 1 and 8 every 21 days is well tolerated and active in patients with NSCLC. These results should be confirmed in comparative studies.