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.