Phase 2 Window Study of SAR439859 (Amcenestrant) Versus Letrozole in Post-menopausal Patients With ER+, HER2- Pre-operative Post-menopausal Primary Breast Cancer

Stopped early · Phase 2

Conditions studied: Breast Cancer

In brief

Primary Objective: To determine whether amcenestrant given at 2 different doses improved the antiproliferative activity when compared to letrozole. Secondary Objectives: * To assess the proportion of participants with a relative decrease from Baseline in percentage of positive tumor cells tested by immunohistochemistry greater than or equal to (\>=) 50 percent (%) (Ki67 \>=50%) in the three treatment arms. * To assess estrogen receptor (ER) degradation in biopsies in participants in the three treatment arms. * To assess safety in the three treatment arms.

Key facts

Study ID

NCT04191382

Run by

Sanofi

People needed

105

Starts

2020-02-04

Expected to finish

2021-05-28

Last updated by the study team

2025-09-18

Who can join

Age: 18 and older. Sex: female. Healthy volunteers: not accepted.

You may qualify if…

• Histological or cytological proven diagnosis of invasive breast adenocarcinoma.
• Localized breast cancer eligible for upfront breast conservative surgery or upfront mastectomy: Stage I, Stage II or operable Stage III (excluded T4) as defined in American Joint Committee on Cancer (AJCC) Cancer Staging Manual 8th edition 2017.
• Postmenopausal women as defined by one of the following:
• Spontaneous cessation of menses greater than (>) 12 months.
• or who had received hormonal replacement therapy but had discontinued the treatment and had follicle stimulating hormone (FSH) level in the postmenopausal range.
• or with status post bilateral surgical oophorectomy.
• or post bilateral ovarian ablation through pelvic radiotherapy.
• Breast tumor size of at least 10 millimeters (mm) in greatest dimension measured by ultrasound.
• Primary tumor had to be positive for Estrogen Receptors (ER+) and negative for HER2 (HER2-) receptor by immunohistochemistry.
• Ki67 level of at least 15% at diagnosis from immunohistochemistry of the tumor.
• Eastern Cooperative Oncology Group (ECOG) performance status 0-1.

You may not qualify if…

• Medical history or ongoing gastrointestinal disorders potentially affecting the absorption of SAR439859 or letrozole.
• Participants unable to swallow normally and to take capsules or tablets.
• Participants with known active hepatitis A, B, C infection; or hepatic cirrhosis.
• Participant with any other cancer; adequately treated basal cell or squamous cell skin cancer or in situ cervical cancer or any other cancer from which the participant had been disease free for >3 years were allowed.
• Evidence of metastatic spread by standard assessment according to local practice.
• Treatment with strong Cytochrome P450 3A (CYP3A) inducers or drugs that had the potential to inhibit uridine diphosphate glucuronosyltransferase (UGT) within 2 weeks before first study treatment administration or 5 elimination half-lives whichever was longest.
• Treatment with drugs that were sensitive substrates of P-glycoprotein (P-gp) or of breast cancer resistance protein (BCRP) within 2 weeks before first study treatment administration or 5 elimination half-lives whichever was longer.
• Use of any investigational agent within 4 weeks prior to randomization.
• Recent use of hormone replacement therapy (last dose less than or equal to [<=] 30 days prior to randomization).
• Prior anti-cancer treatment was not allowed unless it was then completed at least 1 year prior to inclusion into this trial.
• Previous systemic or local treatment for the new primary breast cancer currently under investigation (including surgery, radiotherapy, cytotoxic and endocrine treatments).
• Inadequate hematological or renal function.
• Prothrombin time/international normalized ratio (INR) >1.5 * upper limit of normal (ULN) or outside therapeutic range if received anticoagulation that would have had affected the prothrombin time/INR.
• Any of the following abnormal liver function test results: Aspartate aminotransferase >1.5 * ULN; Alanine aminotransferase >1.5 * ULN; Total bilirubin >1.5 * ULN.
• Participants were employees of the clinical study site or other individuals directly involved in the conduct of the study, or immediate family members of such individuals.
• Sensitivity to any of the study interventions, or components thereof, or drug or other allergy that, in the opinion of the Investigator, contraindicates participation in the study.
• The above information was not intended to contain all considerations relevant to a participant's potential participation in a clinical trial.

Where it is running

• Investigational Site Number 8400014 — Tucson, Arizona, United States
• Investigational Site Number 8400010 — Los Angeles, California, United States
• Investigational Site Number 8400018 — Fort Wayne, Indiana, United States
• Investigational Site Number 8400005 — Lincoln, Nebraska, United States
• Investigational Site Number 8400016 — Winston-Salem, North Carolina, United States
• Investigational Site Number 8400012 — Tacoma, Washington, United States
• Investigational Site Number 0560001 — Leuven, Belgium
• Investigational Site Number 0560002 — Namur, Belgium
• Investigational Site Number 2500001 — Nantes, France
• Investigational Site Number 2500004 — Paris, France
• Investigational Site Number 2500002 — Saint-Cloud, France
• Investigational Site Number 2500003 — Toulouse, France
• Investigational Site Number 3800004 — Meldola, Italy
• Investigational Site Number 3800002 — Milan, Italy
• Investigational Site Number 3800001 — Milan, Italy
• Investigational Site Number 3920002 — Osaka, Japan
• Investigational Site Number 3920003 — Sapporo, Japan
• Investigational Site Number 3920001 — Yokohama, Japan
• Investigational Site Number 8400007 — Hato Rey, Puerto Rico
• Investigational Site Number 6430006 — Moscow, Russia
• Investigational Site Number 6430004 — Moscow, Russia
• Investigational Site Number 6430003 — Saint Petersburg, Russia
• Investigational Site Number 6430007 — Saint Petersburg, Russia
• Investigational Site Number 6430002 — Saint Petersburg, Russia
• Investigational Site Number 7240005 — Barcelona, Spain

Full record on ClinicalTrials.gov

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