Objective: Erlotinib has been reported to be useful for treatment of non-small-cell lung cancer harboring mutation of the epidermal growth factor receptor gene EGFR-mt. However, no prospective trial has yet assessed the utility of erlotinib in Japanese patients.
Methods: Patients with EGFR-mt (exon 19/21) non-small-cell lung cancer who had previously received one to two chemotherapy regimens were enrolled in this trial. Erlotinib was initially administered at a dose of 150 mg/day orally until disease progression or unacceptable toxicities occurred. The primary endpoint was the objective response rate.
Results: Twenty-six patients were enrolled between February 2009 and January 2011. Objective response was observed in 14 patients (53.8%, 95% confidence interval: 33.4-73.4%), and the disease control rate reached 80.8% (95% confidence interval: 60.7-93.5%). After a median follow-up time of 17.3 months (range: 5.8-29.5 months), the median progression-free survival was 9.3 months (95% confidence interval: 7.6-11.6 months). The median survival time is yet to be determined. Major toxicities were skin disorder and liver dysfunction; most episodes were grade 2 or less, and all were tolerable. Only one patient with grade 3 skin rash discontinued the study. No patients developed interstitial lung disease, and there were no treatment-related deaths.
Conclusions: This prospective study is the first to have investigated the usefulness of erlotinib in Japanese patients with previously treated EGFR-mt non-small-cell lung cancer. Although this trial could not meet the primary endpoint, erlotinib was well tolerated and showed clinical benefit such as promising disease control rate or progression-free survival in this population, similar to gefitinib.
Keywords: EGFR; erlotinib; mutation; non-small-cell lung cancer.