Afatinib (GILOTRIF®) in Patients Suffering From Tumors Harboring Neuregulin 1 (NRG1) Gene Alterations (Specifically NRG1 Gene Fusion-positive Advanced Solid Tumors)

Inclusion Criteria to participate in this program: * Confirmed diagnosis of an advanced, unresectable and/or metastatic tumor harboring NRG1 gene fusions characterized as follows: * Gene 1: NRG1 (prerequisite: conservation of the epidermal growth factor (EGF) domain - this will be identified by the lab performing the molecular testing) * Gene 2: All fusion partners are allowed (prerequisite: the region must be a coding region - this will be identified by the lab performing the molecular testing) * Patient must have measurable or evaluable lesions (according to RECIST 1.1). * At least 18 years of age at the time of consent. Exclusion Criteria: * Treatment with a systemic anti-cancer therapy or investigational drug within 14 days or 5 half-lives (whichever is shorter) of the first treatment with the study medication. * Tumors carrying additional gene mutations other than NRG1 fusion where FDA-approved targeted therapy is available * Prior treatment with a therapy targeting erythroblastic leukemia viral oncogene homologue receptors (ErbB) * Any patient considered ineligible by the treating physician.