Efficacy and dose of afatinib in patients with non‐small cell lung cancer after failure of prior gefitinib or erlotinib treatment

BACKGROUND: We report a subgroup analysis of afatinib with respect to its efficacy, safety, and the long‐term survival of patients in a Named Patient Use program at a single institution. METHODS: We analyzed 60 patients with stage IV non‐small cell lung cancer (NSCLC) who had been treated with ≥1 line of platinum‐based chemotherapy and had activating epidermal growth factor receptor (EGFR) mutations or disease control for ≥6 months with prior EGFR inhibitors. Afatinib was started on a daily dose of 50 mg, which was decreased according to the adverse events and tolerability. RESULTS: A total of 13 patients achieved partial remission, whereas 33, 12, and two showed stable disease, had progression, and were not evaluable, respectively, resulting in an objective response rate and disease control rate of 21.7% and 76.7%, respectively. The median progression‐free survival (PFS) was 5.4 (95% confidence interval [CI]: 4.0–7.7) months and median overall survival (OS) was 10.1 (8.5–13.6) months. Toxicities leading to drug discontinuation were experienced by four patients (6.7%). Grade 3 diarrhea occurred in 10 patients (16.7%), and afatinib dose reductions were required in 35 patients. The PFS and OS were significantly longer for patients whose dose was reduced to 40 or 30 mg than for those without dose reduction (7.0 vs 3.1 months and 13.5 vs 8.1 months, respectively, p < 0.05). CONCLUSIONS: The efficacy of afatinib was similar to that identified in the global data without unexpected adverse events. Survival analyses support the currently approved dose of afatinib as first‐line treatment for NSCLC.