A Study to Learn About the Study Medicine Called PF-08046876 in People With Advanced Solid Tumors

Inclusion Criteria: * 18 years of age or older * Advanced cancer of the bladder, lung, head and neck, esophagus, or pancreas * Measurable disease * ECOG Performance status 0-1 * Part 1: progression or relapse following standard treatments * Part 2: maximum of 2 prior lines of systemic therapy in the advanced setting * Resolution of acute effects of prior anticancer therapy to baseline or Grade 1 * Consent to submit required pre-treatment tumor tissue as medically feasible Exclusion criteria: * Received prior treatment with an antibody drug conjugate with a camptothecin-class payload (e.g. sacituzumab govitecan, trastuzumab deruxtecan ) * Active anorexia, nausea or vomiting, and/or signs of intestinal obstruction meeting protocol exclusion * Pulmonary disease meeting protocol exclusion * Other unacceptable abnormalities as defined by protocol