Erlotinib and Gefitinib Offer Similar Benefit in EGFR-Mutated Non–Small Cell Lung Cancer
A retrospective study has shown that two targeted therapy drugs—erlotinib (Tarceva) and gefitinib (Iressa)—achieved similar outcomes among people with metastatic or recurrent non–small cell lung cancer (NSCLC) harboring an EGFR mutation. These EGFR tyrosine kinase inhibitors have previously been reported to offer benefit over standard chemotherapy as first-line treatment of EGFR-positive advanced NSCLC. The study findings by Lim et al are published in the Journal of Thoracic Oncology.
Erlotinib is used worldwide, and gefitinib is widely used in Asian countries and recently in Europe (only for patients with tumors harboring EGFR mutations) but not in the United States. Indirect comparisons of the two agents have resulted in inconsistency with regard to progression-free survival, and until now, the agents have not been compared head-to-head in patients with EGFR-positive NSCLC.
Study Details
The study, conducted in Korea, included a total of 375 patients with recurrent or metastatic stage IIIB/IV NSCLC with EGFR mutation (either exon 19 deletion or L858R mutation in exon 21) who had received either gefitinib or erlotinib. Per the study design, 121 pairs of gefitinib-treated and erlotinib-treated patients were matched according to gender, smoking history, Eastern Cooperative Oncology Group (ECOG) performance status, and type of EGFR mutation. The dose of gefitinib was 250 mg/d orally, and the dose of erlotinib was 150 mg/d orally; the cycle was repeated every 28 days.
The median age of patients was 58 years (range, 30–84), 63.6% of patients were never-smokers, 98.3% had adenocarcinoma, and 90.9% had ECOG scores of 0 or 1. The median number of cycles of EGFR tyrosine kinase inhibitor treatment was 12.7 in the gefitinib group and 10.8 in erlotinib group, and a subgroup of 63 patients received EGFR tyrosine kinase inhibitor treatment as first-line therapy.
Similar Outcomes for Both Agents
The overall response rates were 76.9% for patients treated with gefitinib and 74.4% for patients treated with erlotinib (P = .575), and the disease control rates were 90.1% and 86.8%, respectively (P = .305). Progression-free survival was also similar in the two groups (median, 11.7 vs 9.6 months, respectively; P = .056).
Univariate and multivariate analyses demonstrated that ECOG performance status of at least 2, nonadenocarcinoma histology, presence of central nervous system (CNS) metastasis, and intra-abdominal metastasis were independent risk factors associated with poor progression-free survival in both treatment groups.
The two agents produced similar effectiveness in the subgroup of 63 patients who received gefitinib or erlotinib as first-line therapy, with overall response rates of 76.7% and 90.0%, respectively (P = .431) and a median progression-free survival of 11.7 and 14.5 months (P = .507). Within this subgroup, univariate and multivariate analyses indicated that smoking and CNS metastasis were independent predictors of poor progression-free survival.
“We used a matched-pair design to maximize the reduction of potential bias due to the retrospective nature of study, although the results regarding differences in side effects between the two drugs were not fully determined in this study,” said lead author Myung-Ju Ahn, MD, of Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea. “Based on these results, both gefitinib and erlotinib can be recommended for the treatment of patients with EGFR-mutant NSCLC.”
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
