Erlotinib and Gefitinib Offer Similar Benefit in Nsclc with EGFR Mutation: First Direct Comparison of Drugs in this Population

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. The findings of the study are published in the April issue of the International Association for the Study of Lung Cancer’s journal, the Journal of Thoracic Oncology (JTO).

The study, conducted in Korea, included 121 pairs of gefitinib-treated and erlotinib-treated patients who were matched according to gender, smoking history, Eastern Cooperative Oncology Group (ECOG) performance status, and type of EGFR mutation (exon 19 deletion or the L858R mutation in exon 21). The dose of gefitinib was 250 mg/day orally and the dose of erlotinib was 150 mg/day orally; the cycle was repeated every 28 days.

The overall response rates were 76.9% for patients treated with gefitinib and 74.4% for patients treated with erlotinib (p=0.575); the disease control rates were 90.1% and 86.8%, respectively (p=0.305). Progression-free survival was also similar in the two groups (median, 11.7 versus 9.6 months, respectively; p=0.056).

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=0.431) and a median progression-free survival of 11.7 and 14.5 months (p=0.507). 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,” says Myung-Ju Ahn, MD, Division of Hematology-Oncology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea, lead author of the study and an IASLC member. “Based on these results, both gefitinib and erlotinib can be recommended for the treatment of patients with EGFR-mutant NSCLC.”

Coauthors of the study include IASLC members Jong-Mu Sun, MD, PhD; Jin Seok Ahn, MD, PhD; and Keunchil Park, MD, PhD.

About the IASLC:

The International Association for the Study of Lung Cancer (IASLC) is the only global organization dedicated to the study of lung cancer. Founded in 1974, the association’s membership includes more than 3,800 lung cancer specialists in 80 countries. To learn more about IASLC please visit www.iaslc.org.