Study to Test the Safety and Tolerability of PF-07257876 in Participants With Selected Advanced Tumors.

Inclusion Criteria: * Histological/cytological diagnosis of selected advanced or metastatic tumor * Prior treatment with PD-1 (Programmed cell death 1) or PD-L1 (programmed death-ligand 1) in NSCLC and SCCHN or platinum-based therapy in Ovarian cancer * Confirmed radiographic progression of disease * PD-L1 IHC positivity ≥1% * Have ≥1 measurable lesion as defined by RECIST 1.1 that has not been previously irradiated * Eastern Cooperative Oncology Group performance status 0-1 * Adequate hematologic, renal and liver functions * Resolved acute effects of any prior therapy * Participants in Part 1 must be able to provide archival tumor tissue collected within the prior 6 months or consent to undergo a fresh biopsy during screening. Participants enrolled to the MTD (Maximum Tolerated Dose) cohort in Part 1 must consent to mandatory paired pre-treatment and on-treatment biopsies. Participants in Part 2 must consent to a pre-treatment biopsy and a subset of patients must consent to a paired on-study biopsy as well until the Sponsor deems an adequate number have been received. Exclusion Criteria: * Participants with known brain metastasis larger than 4 cm or that is symptomatic. New brain metastases detected at screening. Participants with previously diagnosed brain metastases are eligible if they have completed treatment and recovered from acute effects prior to study entry. * Abnormal neurological assessment by investigator * Other active malignancy within 3 years prior to enrol…