NCT04191382: AMEERA-4

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

Terminated Phase 2 Results posted Last updated 18 September 2025

What this trial tests

Phase 2 trial testing Amcenestrant (SAR439859) in Breast Cancer in 105 participants. Terminated before completion.

Timeline

4 February 2020

Primary endpoint
30 April 2021

28 May 2021

Quick facts

Lead sponsor	Sanofi
Phase	Phase 2
Status	Terminated
Study type	INTERVENTIONAL
Allocation	randomized
Design	parallel
Masking	single
Primary purpose	treatment
Enrollment	105
Start date	4 February 2020
Primary completion	30 April 2021
Estimated completion	28 May 2021
Sites	32 locations across Belgium, Russia, Ukraine, Japan, United States, Puerto Rico, Spain, Italy

Drugs / interventions tested

• Amcenestrant (SAR439859) — full drug profile →
• Letrozole — full drug profile →

Conditions studied

• Breast Cancer — all drugs for Breast Cancer →

Sponsor

Sanofi — full company profile →

Who can join

18 and older, female only, with Breast Cancer. Patients with the condition only — healthy volunteers not accepted.

Sponsor's own description

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.

Publications & conference data

8 peer-reviewed publications reference this trial (live from Europe PMC):

1. Oral Selective Estrogen Receptor Degraders (SERDs) in Breast Cancer: Advances, Challenges, and Current Status.
   Downton T, Zhou F, Segara D, Jeselsohn R, et al · · 2022 · cited 48× · PMID 36081610 · DOI 10.2147/dddt.s380925
2. AMEERA-1 phase 1/2 study of amcenestrant, SAR439859, in postmenopausal women with ER-positive/HER2-negative advanced breast cancer.
   Bardia A, Chandarlapaty S, Linden HM, Ulaner GA, et al · · 2022 · cited 44× · PMID 35840573 · DOI 10.1038/s41467-022-31668-8
3. Molecular Mechanisms of Anti-Estrogen Therapy Resistance and Novel Targeted Therapies.
   Ozyurt R, Ozpolat B. · · 2022 · cited 31× · PMID 36358625 · DOI 10.3390/cancers14215206
4. Oral SERD, a Novel Endocrine Therapy for Estrogen Receptor-Positive Breast Cancer.
   Neupane N, Bawek S, Gurusinghe S, Ghaffary EM, et al · · 2024 · cited 26× · PMID 38339371 · DOI 10.3390/cancers16030619
5. Detection of <i>ESR1</i> Mutations Based on Liquid Biopsy in Estrogen Receptor-Positive Metastatic Breast Cancer: Clinical Impacts and Prospects.
   Liao H, Huang W, Pei W, Li H. · · 2020 · cited 20× · PMID 33384956 · DOI 10.3389/fonc.2020.587671
6. How I treat endocrine-dependent metastatic breast cancer.
   Gombos A, Goncalves A, Curigliano G, Bartsch R, et al · · 2023 · cited 16× · PMID 36806375 · DOI 10.1016/j.esmoop.2023.100882
7. Development of novel agents for the treatment of early estrogen receptor positive breast cancer.
   Elliott MJ, Cescon DW. · · 2022 · cited 12× · PMID 34903444 · DOI 10.1016/j.breast.2021.11.007
8. Oral SERDs alone or in combination with CDK 4/6 inhibitors in breast cancer: Current perspectives and clinical trials.
   Apostolidou K, Zografos E, Papatheodoridi MA, Fiste O, et al · · 2024 · cited 9× · PMID 38599049 · DOI 10.1016/j.breast.2024.103729