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

A PHASE 1, OPEN-LABEL, DOSE ESCALATION AND DOSE EXPANSION STUDY TO EVALUATE THE SAFETY, TOLERABILITY, PHARMACOKINETICS, AND ANTI-TUMOR ACTIVITY OF PF-07921585 AS A SINGLE AGENT AND IN COMBINATION THERAPY IN PARTICIPANTS 18 YEARS OF AGE AND OLDER WITH ADVANCED SOLID TUMORS

The purpose of this study is to learn about the safety and effects of the study medicine (called PF-07921585) in people with cancer that has advanced or spread to other parts of the body.

This study is seeking participants who have any of the following cancer types:

• non-small cell lung cancer
• colorectal cancer
• bladder cancer
• melanoma (a type of skin cancer)
• kidney cancer
• head and neck cancer Participants will receive the study medicine PF-07921585 alone or in combination with another study medicine called sasanlimab at the study clinic.

PF-07921585 will be given as an infusion into a vein or as shots under the skin, once every 3 weeks. Sasanlimab will be given as shots under the skin, also once every 3 weeks.

The experiences of participants receiving the study medicine will be studied to help see if the study medicine is safe and effective. Participants may receive study medicine for up to 2 years, depending on how the cancer responds to the study treatment. Participants may continue receiving study medicine after 2 years if there are any benefits from the study treatment. Participants will attend visits once every 3 weeks with the first 9 weeks having more frequent visits, to check the safety of the study treatment.

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.

Key Inclusion Criteria:

1. Participants aged ≥18 years or older at the time of informed consent.

2. Tumor types and prior treatment requirements: Participants entering Parts 2 and 3 must have at least 1 measurable lesion.

   Part 1 and Part 2:

   Eligible advanced/metastatic tumor types include NSCLC, urothelial carcinoma (UC), renal cell carcinoma (RCC), melanoma, head and neck squamous cell carcinoma (HNSCC), and microsatellite stable colorectal cancer (MSS-CRC). Participants must have demonstrated radiographic progression on standard treatment(s) for their cancer

   Part 3:

   • Cohort 1: Participants with metastatic melanoma with resistance to checkpoint inhibitor therapy and BRAF/MEKi.
   • Cohort 2: Participants with metastatic MSS-CRC.
   • Cohort 3: Participants with previously untreated metastatic NSCLC.

3. ECOG PS 0 or 1.

Key Exclusion Criteria:

1. Participants with any other active malignancy within 3 years prior to enrollment.
2. Known or suspected hypersensitivity to, or severe allergic history of, human albumin or anti-PD-(L)1 therapy.
3. History of Grade ≥3 immune-related AE (irAE) or unresolved irAEs prior to first dose of study intervention. Exception: vitiligo and endocrinopathy that is controlled with hormonal therapy.
4. History of venous thromboembolic event <12 weeks prior to starting study treatment.
5. Active or history of clinically significant gastrointestinal (GI) disease.
6. Active or history of interstitial lung disease or Grade ≥2 pneumonitis.
7. Active or history of clinically significant autoimmune disease.
8. Active bleeding disorder.
9. Participants who have undergone treatment with any investigational IL-12 agent.
10. Active, uncontrolled infections