A Study to Learn About PF-07921585 Alone or With Other Anti-cancer Medicines in People With Cancer

The study contains 3 parts: Part 1: dose escalation of PF-07921585 as single agent to determine the monotherapy recommended dose for further study. Part 2: dose escalation of PF-07921585 in combination with the anti-PD 1 inhibitor sasanlimab and potentially other anti-cancer agents, in order to determine the recommended dose for expansion of the combination. Part 3: dose optimization/ expansion will evaluate PF-07921585 in combination with sasanlimab, and potentially other anti-cancer agents. After identification of the recommended dose for expansion in Part 2, participants with select solid tumors will be enrolled into 3-4 cohorts as follows: * Cohort 1: Melanoma * Cohort 2: Microsatellite stable (MSS) metastatic colorectal cancer * Cohort 3: Non-small cell lung cancer (NSCLC) * Cohort 4: Solid tumor, tumor types and clinical setting to be determined based on emerging data.