A Phase 2 interventional study of PF-07220060 CDK4 inhibitor and Fulvestrant in Advanced or Metastatic Breast Cancer, sponsored by Pfizer. Active, not recruiting at 48 sites in 14 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-08-20.
Sponsored by Pfizer · Phase 2, Interventional, and Treatment
The purpose of this study is to learn about the safety and how effective the study medicine (PF-07220060) plus fulvestrant is compared to the study doctor's choice of treatment in people with advanced or metastatic breast cancer. Advanced cancer is the one that is unlikely to be cured or taken care of with treatment. Metastatic cancer is the one that has spread to other parts of the body.
This study is seeking female and male participants who:
Half of the participants will take PF-07220060 two times daily by mouth along with fulvestrant. Fulvestrant will be given as a shot into the muscle. The other half will take the study doctor's choice of treatment which can either be:
This study will compare the experiences of participants receiving the study medicine plus fulvestrant to those who are receiving the study doctor's choice of treatment. This will help decide if the study medicine is safe and effective.
Participants will receive study treatment and/or will be in the study until:
12,544 studies on the registry are indexed under Breast Neoplasms; 2,892 are open to participants now.
This study's enrollment of 333 is above the median of 72 across 9,302 interventional studies indexed under Breast Neoplasms.
Browse Breast Neoplasms studies →Pfizer is the lead sponsor of 3,244 studies on the registry; 139 are open to participants now.
Of its 582 completed or terminated interventional studies of FDA-regulated products, 381 (65%) have results posted.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
PF-07220060 to be taken by mouth as a tablet in combination with fulvestrant (a solution for injection)
Drug: PF-07220060 CDK4 inhibitor · Drug: Fulvestrant
Investigator's choice of therapy of either: * Fulvestrant alone (a solution for injection), or * Everolimus in combination with exemestane, both a tablet to be taken by mouth.
Drug: Fulvestrant · Drug: Everolimus · Drug: Exemestane
Experimental
Experimental and Active comparator
Active Comparator
Active Comparator
Progression-Free Survival (PFS) progression, as determined by investigator per Response Evaluation Criteria in Solid Tumors (RECIST) v1.1
Time frame: From Initiation up to 2 years
Overall Survival (OS)
Time frame: Time from the date of randomization to the date of death due to any cause up to approximately 3 years
OR by investigator per RECIST v1.1
Time frame: Time From randomization date (every 8 weeks during the first 48 weeks and then every 12 weeks) to the date of progression OR death whichever occurs first (up to approximately 2 years)
Duration of Response (DOR) as defined by investigator per RECIST v1.1
Time frame: From the date of the first objective response (every 8 weeks during the first 48 weeks and then every 12 week) up to approximately 2 years.
Number of Participants With Clinical Benefit Response (CBR) by investigator per RECIST v1.1
Time frame: From randomization date (every 8 weeks during the first 48 weeks and then every 12 weeks) up to approximately 2 years
Number or Patients with Adverse Events (AEs) by Type
Time frame: From screening until 28 days after the last dose, to approximately 3 years
Number or Patients with AEs by Incidence
Time frame: From screening until 28 days after the last dose, to approximately 3 years
Number or Patients with AEs by Seriousness
Time frame: From screening until 28 days after the last dose, to approximately 3 years
Number or Patients with AEs by relationship to study interventions
Time frame: From screening until 28 days after the last dose, to approximately 3 years
Number of Participants With Abnormal Electrocardiogram (ECG)
Time frame: From baseline to approximately 2 years
Number of Participants With Laboratory Test Abnormalities
Time frame: From screening until 28 days after the last dose to approximately 2 years
EQ-5D-5L
Time frame: Screening Days 1, 15 of Cycle 1 and 2, Day 1 of Cycles 3-6, then Day 1 of every other subsequent Cycle starting with Cycle 8 (eg, Cycles 8, 10, 12, etc) and EoT. Each Cycle is 28 days.
EORTC QLQ
Time frame: Screening Days 1, 15 of Cycle 1 and 2, Day 1 of Cycles 3-6, then Day 1 of every other subsequent Cycle starting with Cycle 8 (eg, Cycles 8, 10, 12, etc) and EoT. Each Cycle is 28 days.
EORTC QLQ Breast Cancer Module 23 (BR23)
Time frame: Screening Days 1, 15 of Cycle 1 and 2, Day 1 of Cycles 3-6, then Day 1 of every other subsequent Cycle starting with Cycle 8 (eg, Cycles 8, 10, 12, etc) and EoT. Each Cycle is 28 days.
Ctrough of PF-07220060
Time frame: Cycle 1 (Day 15), Cycle 2 (Day 1), and Cycle 3 (Day 1). Each Cycle is 28 days
Plan to share: Yes — 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.
This study is active, not recruiting, as verified in Aug 2026. You cannot join it, but the record below documents what was studied.
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