The purpose of this study is to learn about the safety and the effects of PF-08046037 alone or with sasanlimab for the treatment of certain advanced or metastatic malignancies. This study is seeking participants who: * have advanced or metastatic non-small cell lung cancer (NSCLC), head and neck squamous cell carcinoma (HNSCC), melanoma, or pancreatic ductal adenocarcinoma (PDAC); * are able to provide tumor tissue samples; * have measurable disease. All participants will receive while at the clinic PF-08046037 alone as an intravenous (IV) infusion (given directly into a vein) or with sasanlimab as a subcutaneous (SQ) injection (given under the skin) once every 3 weeks. Participants will continue to take the study drug(s) until their cancer is no longer responding or if the patient cannot safely take them. The study team will monitor how each participant is doing with the study treatment during regular visits at the study clinic.