Avelumab With Bempegaldesleukin With or Without Talazoparib or Enzalutamide in Advanced or Metastatic Solid Tumors

Inclusion Criteria: * Participants must be ≥ 18 years old. * Participants with SCCHN or mCRCP. * Participants must have histological diagnosis of solid tumors and provide tumor tissue. * Measurable disease by RECIST v1.1 with at least 1 measurable lesion. * Eastern Cooperative Oncology Group (ECOG) Performance Status (PS) 0 or 1. * Adequate bone marrow, renal and liver function * Highly effective contraceptive use by men with the ability to father a child or women of childbearing potential. * A WOCBP must have a negative highly sensitive pregnancy test (\[urine or serum\] as required by local regulations) at C1D1. * Signed and dated informed consent. Exclusion Criteria: * Known prior severe hypersensitivity to investigational products or any component in their formulations, including known severe hypersensitivity reactions to monocolonal antibodies. * Known history of: immune-mediated colitis, inflammatory bowel disease, pneumonitis, or pulmonary fibrosis. * Active or prior autoimmune disease that might deteriorate when receiving an immunostimulatory agent. * Prior organ transplantation including allogenic stem cell transplantation. * Vaccination within 4 weeks prior to C1D1 and while on trial is prohibited except for administration of inactivated vaccines. * Known symptomatic brain lesions requiring steroids. * Known history of testing positive for human immunodeficiency virus (HIV or known acquired immunodeficiency syndrome (AIDS). * Positive HBV surface antigen or HCV t…