Purpose: To investigate the efficacy and relationship between plasma concentrations at the end of infusion (C(end of infusion)) and toxicity profile of fixed-dose-rate gemcitabine plus carboplatin in chemotherapy-naive patients with advanced non-small-cell lung cancer (NSCLC).
Patients and methods: Patients were given gemcitabine by 120 min infusion [at a fixed dose rate (FDR) of 10 mg/m(2)/min] on days 1 and 8 of a 21-day cycle, immediately followed by carboplatin AUC 5 by 4 h infusion on day 1. C (end of infusion) of gemcitabine was determined by ion-pair reversed-phase high-performance liquid chromatography (HPLC).
Results: By the close-out date, in our study population, the estimated median time to tumor progression (TTP) was 7 months (95% CI 4-10 months), median overall survival (OS) was 12 months (95% CI 11.2-12.8 months). The mean value of C (end of infusion) of 21 eligible patients was 16.48 +/- 8.07 micromol/l (range 27.43-2.87 micromol/l). The main hematological toxicities were transient grade 3-4 thrombocytopenia. The mean percentages of reduction of WBC, NEC, PLTC and Hb of 21 eligible patients were 38.3 +/- 38.1%, 31.3 +/- 73.6%, 31.8 +/- 53.5% and 12.0 +/- 12.2%, respectively. The analysis of the C(end of infusion) of gemcitabine and the percentage of reduction in WBC showed a significant correlation (r(2) = 0.4575; p < 0.05). A significant correlation (r(2) = 0.5671; p < 0.05) was also observed between the percentage of reduction of PLTC and C(end of infusion) of gemcitabine infusion.
Conclusion: The clinical data in this trial supports the further evaluation the regimen in advanced NSCLC patients, due to its predictable kinetic behavior and less severe toxicity profile than expected.