A Trial Using ARV-471 or Anastrozole in Post-Menopausal Women With Breast Cancer Prior to Surgery

What this trial studies

This trial is a Phase 2 neoadjuvant study evaluating ARV-471 or anastrozole in post-menopausal women with estrogen receptor positive/ human epidermal growth factor receptor 2 (ER+/HER2)- localized breast cancer.

Conditions in scope

• Breast Cancer

Interventions

• ARV-471 (Drug) — 100 mg tablet
• Anastrozole (Drug) — 1 mg tablet
• Surgical resection of breast tumor (Procedure) — Surgical resection approximately 5.5 months after starting treatment (C6D18 ± 14 days)

Who can join

Women only · Ages 18 Years and up

Inclusion criteria

• Post-menopausal females ≥ 18 years.
• Histologically or cytologically confirmed ER+ and HER2- breast cancer (per local assessment). ER and HER2 status must be documented:
• ER+ disease, with ER staining of ≥ 10% of tumor cell nuclei by immunohistochemistry (IHC) per American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) guidelines.
• HER2- disease by either IHC or in situ hybridization per ASCO/CAP guidelines.
• Ki-67 score ≥ 5%, analyzed locally.
• Clinical T1c-T4c, N0-N2, M0 breast cancer amenable to definitive surgical resection, without bilateral breast ductal carcinoma in situ or invasive breast cancer.
• The primary tumor must be at least 1.5 cm by imaging.
• Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.

Exclusion criteria

• Any other active malignancy within 3 years prior to enrollment, except for adequately treated basal cell or squamous cell skin cancer, or cervical carcinoma in situ.
• Any of the following in the previous 6 months: 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.
• Any of the following in the previous 6 months: Congenital long QT syndrome; Torsade de Pointes; Sustained ventricular tachyarrhythmia and ventricular fibrillation; Left anterior hemiblock (bifascicular block); Ongoing cardiac dysrhythmias of NCI CTCAE ≥ Grade 2; Atrial fibrillation of any grade (≥ Grade 2 in the case of asymptomatic lone atrial fibrillation).
• corrected QT (Fridericia method) (QTcF) \> 470 msec.
• Active, uncontrolled bacterial, fungal or viral infection, including (but not limited to) hepatitis B virus (HBV), hepatitis C virus (HCV), and known human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS)-related illness.
• Active inflammatory gastrointestinal disease, chronic diarrhea, known uncontrolled diverticular disease, or previous gastric resection or lap band surgery.
• Cirrhosis meeting criteria for Child Pugh B and C.
• Prior treatment for breast cancer including systemic therapy (eg, chemotherapy, hormonal therapy), radiation, surgery, or any investigational agents.

Eligibility wording paraphrased from the public record. View the full criteria on ClinicalTrials.gov before contacting a site.

Where it’s happening

Showing the first 10 of 49 sites. See all sites on ClinicalTrials.gov.

Status & timeline

• Overall status: Completed
• Study type: Interventional
• Phase: PHASE2
• Start date: 2023-02-15
• Primary completion: 2024-07-13
• Last update posted: 2025-08-29
• First posted: 2022-09-22

Sponsor & contact

Lead sponsor: Arvinas Inc. (Industry)

Collaborators: Pfizer

For trial site contact information, use the official record at ClinicalTrials.gov. Contact details change frequently and the public record is the source of truth.

Outcome measures

Primary outcomes

• Percent Reduction in Ki-67 Expression From Baseline to Day 15 in Tumor Biopsies (Baseline (during screening, prior to Day 1) and Day 15)
  Tumor biopsy Ki-67 expression (% of tumor cells that are positive for Ki-67) at baseline and Cycle 1 Day 15 (C1D15) was collected. Ki-67 expression was assessed by immunohistochemical staining in a central laboratory. The log-transformed Ki-67 after approximately 2 weeks of treatment as a percentage of the baseline value, ie, the ratio between the Ki-67 measurements obtained from C1D15…

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