A Study to Learn About the Study Medicine Called PF-08032562 in People With Advanced or Metastatic Solid Tumors

A PHASE 1 DOSE ESCALATION AND EXPANSION STUDY TO EVALUATE SAFETY, TOLERABILITY, PHARMACOKINETICS, PHARMACODYNAMICS, AND ANTI-TUMOR ACTIVITY OF PF-08032562 IN PARTICIPANTS WITH ADVANCED OR METASTATIC SOLID TUMORS

The purpose of this study is to learn about the safety and effects of the study medicine when given alone or together with other anti-cancer therapies. Anti-cancer therapy is a type of treatment to stop the growth of cancer. This study also aims to find the best amount of study medication.

This study is seeking participants that have advanced or metastatic breast cancer (BC), or advanced or metastatic colorectal cancer (CRC).

All participants in this study will take the study medication (PF-08032562) as pill by mouth. This will be repeated for 28-day cycles.

Depending on which part of the study participants are enrolled into, they will receive the study medication PF-08032562 alone or in combination with other anti-cancer medications. The study medication (PF-08032562) will be taken by mouth (PO) in combination with other anti-cancer medications given in the study clinic by intramuscular (IM) injection into the muscle or intravenous (IV) infusion that is directly injected into the veins at different times (depending on the treatment) during the 28-day cycle. The study may also test different schedules.

Inclusion Criteria:

• 18 years of age or older
• Advanced or metastatic cancer of the breast or colon Part 1A: metastatic or advanced breast cancer or colorectal cancer for which no standard therapy is available Part 1B: metastatic or advanced breast cancer with disease progression after at least 1 line of treatment with an endocrine therapy and CDK4/6 inhibitor in the advanced or metastatic setting Part 1C: metastatic or advanced colorectal cancer with at least having received chemotherapy and/or targeted therapy if appropriate Part 1D: metastatic or advanced colorectal cancer without any prior chemotherapy for advanced or metastatic disease Part 2A: metastatic or advanced breast cancer with disease progression after at least 1 prior line of CDK4/6 inhibitor and at least 1 prior line of endocrine therapy Part 2B: metastatic or advanced colorectal cancer with at least having received chemotherapy and/or targeted therapy if appropriate Part 2C: metastatic or advanced colorectal cancer without any prior chemotherapy for advanced or metastatic disease
• Measurable disease
• ECOG performance status 0 or 1

Exclusion Criteria:

• Active malignancy within 3 years prior to enrollment
• Known symptomatic brain metastases requiring steroids
• Advanced/metastatic, symptomatic, visceral spread, that are at risk of life-threatening complications in the short term
• Prior irradiation to >25% of the bone marrow
• Hypertension that cannot be controlled by optimal medical therapy
• Renal impairment
• Hepatic dysfunction
• Cardiac abnormalities
• Active bleeding disorder
• Active or history of clinically significant GI disease
• Other unacceptable abnormalities as defined by protocol