Afatinib in NSCLC With HER2 Mutation

Inclusion criteria: * Patients with Histologically or cytologically confirmed diagnosis of stage IIIb/IV NSCLC (AJCC 7.0), who had failed one or two systemic chemotherapy regimens, one of which must be platinum-based . * Tumor tissue with HER2 mutations as confirmed by AmoyDx® HER2 Mutation Detection Kit * Patients with at least one measurable tumor lesion that can accurately be measured by CT scan or MRI according to RECIST 1.1 * Age\>=18 years * Eastern Cooperative Oncology Group (ECOG) performance score 0 or 1 * Adequate organ function * Recovered from any previous therapy related toxicity to \<=Grade 1 at study entry (except for stable sensory neuropathy \<=Grade 2 and alopecia) * Written informed consents that is consistent with International Conference on Harmonisation (ICH) - Good Clinical Practice (GCP) and local GCP guidelines Inclusion criterion for Part B * Adequate organ function, as inclusion criteria No.6 * ECOG performance score 0\~2 * More than 12 weeks clinical benefit (PR, Complete Response (CR), SD) in part A Further inclusion criteria apply Exclusion criteria: * Prior treatment with Epidermal Growth Factor Receptor (EGFR) or HER2 targeting small molecules or antibodies. * Any chemo-, or immune anticancer therapy within 4 weeks prior to start of study treatment, Hormonal treatment within 2 weeks prior to start of study treatment, Radiotherapy within 4 weeks prior to start of treatment, except as follows: i.) Palliative radiation to target organs other…