Pfizer has made an internal business decision to not continue further development of PF-07265807. This decision was not due to major safety concerns or requests from any regulatory authorities.

A First-in-Human Pharmacokinetic, Safety, and Tolerability Study of PF-07265807 as Monotherapy and in Combination in Participants with Advanced or Metastatic Solid Tumors

Inclusion Criteria:

• At least one measurable (Parts 1-4) or non-measurable lesion (Parts 1-3), not previously irradiated, as defined by RECIST 1.1
• ECOG Performance Status 0 or 1, 2 with approval
• Adequate Bone Marrow Function
• Adequate Renal Function
• Adequate Liver Function
• Resolved acute effects of any prior therapy
• Able to provide adequate archival tumor tissue or freshly obtained tumor tissue (some participants will require mandatory pre- and on-treatment biopsy is part of the biomarker cohort).
• Life expectancy of at least 3 months.
• Part 1 and Part 2: Participants who are intolerant or resistant to standard treatment for selected solid tumors.
• Part 3: Participants with advanced/metastatic RCC with a clear cell component and progressed with no standard therapy available.
• Part 4, Cohort 1: Participants with NSCLC with METex14-skipping alteration(s) and progressed on at least 1 prior therapy.
• Part 4, Cohort 2: Participants with MSS CRC with intermediate TMB and progressed with no satisfactory alternative treatment available, but has not received prior treatment with an anti-PD-(L)1 therapy.
• Part 4, Cohort 3: Participants with metastatic gastric or GEJ adenocarcinoma that is PD-L1 positive that has progressed on at least 2 but no more than 3 prior chemotherapy regiments, but has not received prior treatment with an anti-PD-(L)1 therapy.
• Part 4, Cohort 4: Participants with metastatic RCC with a clear cell component with IMDC intermediate or poor risk that have not received any prior systemic therapy for metastatic disease.

Exclusion Criteria:

• Known active uncontrolled or symptomatic CNS metastases.
• Any other active malignancy within 2 years prior to enrollment.
• Major surgery within 6 weeks, radiation therapy within 4 weeks, systemic anti-cancer therapy within 2 week or 5 half-lives (4 weeks or 5 half-lives for antibody therapies or investigational drug(s) taken on another study) prior to study entry.
• Active or history of autoimmune disease requiring >10mg/day prednisone or other concurrent immunosuppressive therapy.
• Active, uncontrolled infection (controlled HBV, HCV, HIV/AIDS may be allowed) as defined in protocol.
• Retinal or other serious ophthalmic disorders as defined in protocol.
• Clinically significant cardiac disease as defined in protocol.
• Uncontrolled HTN that cannot be controlled by medications.
• Inability to consume or absorb study drug.
• Known or suspected hypersensitivity to PF-07265807.
• Prohibited concomitant medications as defined in protocol.
• Active inflammatory GI disease, uncontrollable chronic diarrhea, or previous gastric resection or lap band surgery affecting absorption.
• Active bleeding disorder.
• Discontinuation of prior checkpoint inhibitor for treatment-related toxicity.
• Experienced >= G3 treatment-related irAE with prior PD-(L)1 agent.
• Prior treatment with selective AXL/MERTK inhibitors

For participants receiving sasanlimab:

- Known history of non-infectious pneumonitis that required steroid treatment or current pneumonitis.

Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical\_trials/trial\_data\_and\_results/data\_requests.