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Examining the effects of PF-07220060 with letrozole in postmenopausal women with breast cancer

AN INTERVENTIONAL, OPEN-LABEL, RANDOMIZED, MULTICENTER, PHASE 2 STUDY OF PF-07220060 PLUS LETROZOLE COMPARED TO LETROZOLE ALONE IN POSTMENOPAUSAL WOMEN 18 YEARS OR OLDER WITH HORMONE RECEPTOR-POSITIVE, HER2-NEGATIVE BREAST CANCER IN THE NEOADJUVANT SETTING

Phase 2 Interventional Pfizer · NCT06465368

This study is testing if a new drug called PF-07220060 combined with letrozole can help postmenopausal women with hormone receptor-positive, HER2-negative breast cancer more than letrozole alone.

Quick facts

PhasePhase 2
Study typeInterventional
Enrollment118 (estimated)
Ages18 Years and up
SexFemale
SponsorPfizer Industry-sponsored
Drugs / interventionschemotherapy, radiation
Locations28 sites (San Antonio, Texas and 27 other locations)
Trial IDNCT06465368 on ClinicalTrials.gov

What this trial studies

This study investigates the effects of the investigational drug PF-07220060 in combination with letrozole compared to letrozole alone in postmenopausal women diagnosed with hormone receptor-positive, HER2-negative breast cancer. Participants will be randomly assigned to receive either the combination treatment or letrozole alone. The study aims to assess the efficacy and safety of the new treatment regimen in this specific patient population. Eligible participants must be treatment-naive and willing to undergo biopsies during the study.

Who should consider this trial

Good fit: Ideal candidates are postmenopausal women aged 18 and older with confirmed HR-positive, HER2-negative breast cancer who have not received prior treatment.

Not a fit: Patients who have previously undergone treatment for breast cancer or have certain medical conditions may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide a new treatment option that may improve outcomes for women with hormone receptor-positive, HER2-negative breast cancer.

How similar studies have performed: Other studies have shown promise in similar approaches, but this specific combination is being evaluated for the first time.

Eligibility criteria

Show full inclusion / exclusion criteria 
Inclusion Criteria:

* Postmenopausal women with histologically confirmed HR-positive and HER2-negative BC (per local assessment)
* Documented by estrogen receptor (ER) and/or progesterone receptor (PR)-positive disease by IHC or ISH
* Participants must have Ki-67 score \>/=10% with unilateral, invasive T1c-T4c, N0-N2, M0 BC
* Participants must be willing and able to undergo a baseline and Day 14 biopsy and must have an ECOG PS or 0 or 1.
* Participants must be treatment naive for the treatment of BC and cannot have had prior treatment with any systemic therapy (e.g., chemotherapy, hormonal therapy), radiation, surgery, or any investigational agents or use of hormone replacement therapy (HRT) or any other estrogen-containing medication (including vaginal estrogen) within 2 weeks prior to diagnostic tissue sample taken.

Exclusion Criteria:

* No prior systemic therapy, radiation, surgery, investigational therapy for treatment of breast cancer
* Certain medical conditions in the previous 6 months, for example: myocardial infarction, severe unstable angina, coronary/peripheral artery bypass graft, symptomatic congestive heart failure (New York Heart Association class III or IV), cerebrovascular accident, transient ischemic attack, symptomatic pulmonary embolism or other clinically significant episode of thromboembolism
* Lab abnormalities outside protocol specified parameters

Where this trial is running

San Antonio, Texas and 27 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
View on ClinicalTrials.gov → Find more trials like this →
Conditions Breast Cancerhuman epidermal growth factor receptor 2hormone receptorHER2-negativeHR-PositiveNeoadjuvantPostmenopausal
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.