IntroductionAfatinib is an oral, irreversible ErbB family blocker approved for first-line treatment of metastatic epidermal growth factor receptor (EGFR) mutation–positive non–small cell lung cancer (NSCLC). The expanded access program (EAP) allowed early access to afatinib and provided additional data on its safety, tolerability, and efficacy.MethodsThe afatinib EAP was an open-label, multicenter, single-arm program in the United States that treated and followed patients with locally advanced or metastatic NSCLC harboring EGFR mutations. Afatinib 40 mg was administered orally once daily until discontinuation due to disease progression, adverse events (AEs), or transition to commercially available drug.ResultsThree hundred twenty-two patients received ≥1 dose of afatinib. Most patients had received prior therapies. Drug-related AEs occurred in 89.4% of patients, including 7.8% with serious AEs. The most common afatinib-related AEs (all grades) were diarrhea (77.0%) and rash (36.0%). Dose reductions occurred in 31.1% of patients. Discontinuation rates due to diarrhea (1.6%) or rash/acne (0.3%) were low. Efficacy data were collected and analyzed when available, with 17.1% and 69.9% of patients achieving objective response and disease control, respectively, in this highly pretreated population.ConclusionsNo additional or unexpected safety concerns were revealed, and afatinib demonstrated antitumor activity in a heavily pretreated NSCLC patient population in a routine clinical setting.Trial RegistrationClinicalTrials.gov Identifier: NCT01649284.FundingBoehringer Ingelheim Pharmaceuticals, Inc.