Afatinib in heavily pretreated advanced NSCLC patients who progressed following prior gefitinib or erlotinib: Compassionate use program in Korea

Introduction: Afatinib, an irreversible ErbB family blocker, approved for first-line treatment of epidermal growth factor receptor (EGFR) mutated advanced non-small cell lung cancer (NSCLC). This study investigated experience of afatinib within a compassionate use program (CUP). Methods: The afatinib CUP was an open-label, multicenter, single-arm program in Korea. We enrolled patients with stage IV NSCLC and who had received at least one line of previous cytotoxic chemotherapy and previous EGFR TKI treatment with either an EGFR mutation or documented clinical benefit. The starting dose of afatinib was 50 mg once daily. Results: From August 2011 to September 2014, 332 patients received at least one dose of afatinib. Most patients were registered in the CUP for fourth- or fifth-line treatment with afatinib. Adverse events (AEs) occurred in 98.1% of patients, including 29.8% with serious AEs. The most common AEs (all grades) were diarrhea (90.1%) and skin rash (62.0%). Dose reductions occurred in 60.5% of patients and discontinuations due to AEs were reported in 11.1% of patients. The response rate and median time to treatment failure (TTF) were 27.4% and 3.3 months (CI 95%, 2.8–3.8 months), respectively, in this highly pretreated population. In subgroup analysis, ECOG PS 0 or 1 and immediate pretreatment with pemetrexed monotherapy or a platinum doublet were associated with a longer TTF for afatinib. Conclusions: No additional or unexpected safety concerns were observed, and afatinib demonstrated moderate antitumor activity in advanced NSCLC patients with acquired resistance to gefitinib or erlotinib in a real-world setting.