Objective: We conducted a phase I dose escalation study to determine the maximum tolerated dose, recommended dose, and safety profile of a biweekly gemcitabine and carboplatin combination regimen in the treatment of patients with completely resected nonsmall cell lung cancer (NSCLC).
Patients and methods: Patients with completely resected pathologically documented stage IB, II, or IIIA NSCLC, performance status (ECOG) 0-1, with adequate bone marrow, renal, liver, and cardiac functions, were treated with gemcitabine and carboplatin. The starting dose was gemcitabine 800 mg/m2 on days 1 and 15 and carboplatin area under the time-concentration curve (AUC) 4 mg/mL/min on day 1. Gemcitabine was increased to 1000 mg/m2 (level 3). Carboplatin was increased to AUC 5 (level 2, 3). The regimen was performed every 4 weeks. The dose-limiting toxicity of the regimen was assessed during the first chemotherapy cycle.
Results: Nine patients were enrolled in this study. All patients were assessed for safety. Grade 3 leukopenia occurred in 1 patient (11%) and grade 3/4 neutropenia occurred in 3 patients (33%). No other grade 3/4 toxicity was observed. No dose-limiting toxicity was experienced at dose levels 1, 2, and 3 of this schedule.
Conclusion: Maximum tolerated dose was not reached in this study. Considering treatment continuation, the recommended dose for a phase II study is gemcitabine 1000 mg/m2 on days 1 and 15 and carboplatin AUC 5 on day 1, every 4 weeks. Biweekly administration of gemcitabine and carboplatin is a feasible and well-tolerated regimen for the treatment of patients with completely resected NSCLC as adjuvant chemotherapy.