About the study

The purpose of this clinical trial is to learn about the safety and effects of the study medicine (called PF-07220060 and PF-07104091) in people with breast cancer. This clinical study consists of 2 parts (part 1 and part 2). In part 1, we are seeking participants who: - Have been diagnosed with Breast Cancer (BC) of either types: - Have HR+, HER2- BC - Refractory HR-positive/HER2-positive BC - Have other solid tumors other than BC In part 2, we are seeking participants who: -Have HR-positive/HER2-negative BC Part 1 will include increasing doses of PF-07220060 with PF-07104091. In part 2, participants will take 1 of 2 study medicine combinations. This will help us decide the highest amount of study medicines that can be safety given to people. All participants in this study will receive PF-07220060 with PF-07104091 by mouth. We will compare participant experiences to help us determine if PF-07220060 with PF-07104091 is safe and effective. Participants will take part in this study for about 2 years. During this time, they will receive the study medicine, an x-ray imaging, and will be observed for safety and effects of the study medicines.

Who can take part?

You may be eligible to participate in the study if you meet the following criteria:

Inclusion criteria

1. Part 1: Breast Cancer (BC)
2. HR+, HER2
3. BC
4. Refractory HR-positive/HER2-positive BC
5. Part 1: Solid Tumors other than BC
6. Part 2:
7. HR-positive/HER2-negative BC
8. Lesion:
9. Part 1: evaluable lesion (including skin or bone lesion only)
10. Part 2: measurable lesion per RECIST v1.1
11. Prior systemic Treatment
12. Part 1: HR-positive/HER2-negative BC
13. At least 1 line of SOC, including CDK4/6 inhibitor therapy and Endocrine Therapy, for advanced or metastatic disease.
14. Prior chemotherapy in the metastatic setting is allowed.
15. Part 1: HR-positive/HER2-positive BC
16. At least 1 prior treatment of approved HER2 targeting therapy.
17. Part 1: Solid Tumors other than BC
18. Participants with no standard therapy available or for which no local regulatory approved standard therapy is available that would confer significant clinical benefit in the medical judgement of the investigator.
19. Part 2A: At least 1 prior systemic therapy for advanced or metastatic disease, including CDK4/6 inhibitor treatment and ET.
20. Parts 2A and 2B: At least 1 prior endocrine therapy for advanced or metastatic disease.
21. Part 2B: Up to 1 prior line of chemotherapy for advanced/metastatic disease is allowed.
22. General

For a full list of inclusion/exclusion criteria, please visit ClinicalTrials.gov

Study locations

Enter your ZIP code/Postal code/PIN code to locate study sites near you:

How to apply

Determine if a study site for this clinical trial is near you. Contact the study to apply.