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Hormone Therapy

PF-07220060 + Letrozole for Breast Cancer

Phase 2
Recruiting
Research Sponsored by Pfizer
Eligibility Criteria Checklist
Specific guidelines that determine who can or cannot participate in a clinical trial
Must have
Postmenopausal women with histologically confirmed HR-positive and HER2-negative BC (per local assessment)
Participants must have Ki-67 score >/=10% with unilateral, invasive T1c-T4c, N0-N2, M0 BC
Timeline
Screening 3 weeks
Treatment Varies
Follow Up pre-dose within 30 minutes and post-dose within 1 hour before or after biopsy
Awards & highlights

Summary

This trial is studying the effects of a new medicine called PF-07220060 when used in combination with letrozole for treating breast cancer. They are looking for women over 18 years old who

Who is the study for?
This trial is for postmenopausal women aged 18 or older with a specific type of untreated breast cancer that's HR positive and HER2 negative. They must not have had prior systemic therapy, radiation, surgery, or certain medications recently. Participants need to be able to undergo biopsies and have an ECOG performance status of 0 or 1.
What is being tested?
The study compares the effects of PF-07220060 combined with letrozole versus letrozole alone in treating breast cancer. Women will be randomly assigned to one of these treatments; both are oral medications taken for a period of 14 days followed by assessments.
What are the potential side effects?
While specific side effects aren't listed here, participants can expect potential side effects from PF-07220060 plus letrozole similar to those common in cancer therapies such as fatigue, nausea, hormonal changes, and possible reactions at the biopsy site.

Eligibility Criteria

Inclusion Criteria

You may be eligible if you check “Yes” for the criteria below
Select...
I am a postmenopausal woman with HR-positive, HER2-negative breast cancer.
Select...
My breast cancer has a Ki-67 score of 10% or higher and is in stages T1c to T4c, N0 to N2, M0.
Select...
I haven't received any treatment for breast cancer before, including surgery, radiation, or medication.
Select...
My cancer is positive for estrogen or progesterone receptors.

Timeline

Screening ~ 3 weeks
Treatment ~ Varies
Follow Up ~pre-dose within 30 minutes and post-dose within 1 hour before or after biopsy
This trial's timeline: 3 weeks for screening, Varies for treatment, and pre-dose within 30 minutes and post-dose within 1 hour before or after biopsy for reporting.

Treatment Details

Study Objectives

Study objectives can provide a clearer picture of what you can expect from a treatment.
Primary study objectives
Rate of Ki-67
Secondary study objectives
Circulating tumor DNA (ctDNA) measurements
Ctrough and peri-biopsy plasma concentrations of PF-07220060
Percentage of Ki-67

Trial Design

2Treatment groups
Experimental Treatment
Active Control
Group I: Arm A/Experimental/PF-07220060 plus letrozoleExperimental Treatment2 Interventions
PF-07220060 given as tablet by mouth twice a day for 14 days. Letrozole given as tablet by mouth once a day for 14 days.
Group II: Arm B/Control/letrozoleActive Control1 Intervention
Letrozole given by mouth once a day for 14 days.
Treatment
First Studied
Drug Approval Stage
How many patients have taken this drug
letrozole
1998
Completed Phase 3
~16660

Find a Location

Who is running the clinical trial?

PfizerLead Sponsor
4,625 Previous Clinical Trials
14,284,076 Total Patients Enrolled
114 Trials studying Breast Cancer
41,353 Patients Enrolled for Breast Cancer
Pfizer CT.gov Call CenterStudy DirectorPfizer
3,518 Previous Clinical Trials
11,458,652 Total Patients Enrolled
45 Trials studying Breast Cancer
17,684 Patients Enrolled for Breast Cancer
~79 spots leftby Oct 2025
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