Objectives: We conducted a phase I trial of erlotinib, an epidermal growth factor receptor tyrosine kinase inhibitor, combined with amrubicin, a topoisomerase II inhibitor. The aim was to determine the maximum tolerated dose, the dose-limiting toxicities (DLTs), and the pharmacokinetics of this combination in patients with non-small cell lung cancer who had received previous chemotherapy.

Methods: A total of 9 patients with stage IV disease were treated at 3-week intervals with erlotinib once daily on days 1 through 21 plus a 5-minute intravenous injection of amrubicin on days 1 through 3.

Results: The dose levels evaluated were erlotinib (mg/body)/amrubicin (mg/m): 100/30 (n=3), 100/35 (n=3), and 150/30 (n=3). The maximum tolerated dose of erlotinib and amrubicin was 100 mg/body and 35 mg/m because 2 of the 3 patients experienced DLTs during the first cycle of treatment at the third dose level of 150 mg/body and 30 mg/m. Cessation of erlotinib administration for 8 days because of grade 3 leukopenia and grade 3 skin infection (erysipelas) were the DLTs. No drug-drug interactions between erlotinib and amrubicin were observed in this study. The overall response rate was 33%, including 3 partial responses, in the 9 patients. The median progression-free survival for all patients was quite long, 11.3 months, and the median overall survival has not yet been reached.

Conclusions: Combined erlotinib plus amrubicin therapy seems to be highly effective, with acceptable toxicity, against non-small cell lung cancer. The recommended dose for phase II studies was erlotinib 100 mg once daily on days 1 through 21, and amrubicin 35 mg/m on days 1 through 3 administered every 21 days.