Efficacy of erlotinib as first-line maintenance therapy in patients with locally advanced or metastatic nonsmall cell lung cancer who have not experienced disease progression or unacceptable toxicity during chemotherapy

Background: First-line maintenance with erlotinib in nonsmall cell lung cancer (NSCLC) patients without progression after four cycles of chemotherapy was well tolerated and significantly prolonged progression-free survival (PFS) compared with placebo. Aim and Design: This open-label, single arm, Phase IV, interventional study was designed to evaluate erlotinib as first-line maintenance after chemotherapy in Indian NSCLC patients. Primary efficacy objective was to evaluate PFS rate (PFSR) at week 52 and secondary objectives were determination of PFS, overall survival (OS), overall response rate (ORR), disease control rate, and safety. Subjects and Methods: Patients were treated with erlotinib until disease progression/death/unacceptable toxicity or end of study. Patients with disease progression underwent scheduled clinical assessments every 12 weeks thereafter. Kaplan–Meier estimates were used to evaluate PFSR, PFS, and OS. The ORR was summarized using number and percentage along with two-sided 95% Clopper–Pearson confidence interval. The incidence of adverse events (AEs) and serious AEs (SAEs) was tabulated according to severity, outcome, and relationship to erlotinib. Results: Of the 51 enrolled patients, 47 patients completed the study (2: Continuing treatment, 41: Disease progression, and 4: Death) and four patients discontinued treatment (3: Lost to follow-up; 1: Withdrew consent). PFSR was 22.5% at 12 months, median PFS 99 days (14.14 weeks), and median OS was 671 days (22 months). The probability of OS was 74.5% at 14 months. The ORR was 25.5%, and disease control rate was 55.3%. AEs were reported in 62.7% and SAE in 7.8% of patients. Common AEs were diarrhea and rash. Conclusions: Erlotinib was well tolerated by Indian patients in first-line maintenance setting and resulted in median PFS of 14 weeks and median OS of 22 months better than previously reported and with no new safety concerns in this population.