Sanofi is discontinuing the global clinical development program of amcenestrant, an investigational oral selective estrogen receptor degrader (SERD). The decision is based on the outcome of a prespecified interim analysis of the Phase 3 AMEERA-5 trial evaluating amcenestrant in combination with palbociclib compared with letrozole in combination with palbociclib in patients with estrogen receptor-positive (ER+)/human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer.
An Independent Data Monitoring Committee (IDMC) found that amcenestrant in combination with palbociclib did not meet the prespecified boundary for continuation in comparison with the control arm and recommended stopping the trial. No new safety signals were observed. Trial participants will be transitioned to letrozole in combination with palbociclib or another appropriate standard of care therapy, as determined by their physician.
The company will continue to review the data and plans to share the results with the scientific community in the future. All other studies of amcenestrant, including in early-stage breast cancer (AMEERA-6), will be discontinued.
John Reed, MD, PhD
Global Head of Research and Development at Sanofi
“While we are disappointed by this outcome, our research will further the scientific understanding of endocrine therapies in people with breast cancer. Our sincere gratitude goes to the patients, families and healthcare professionals involved in the amcenestrant clinical development program. Oncology remains a priority area for Sanofi, and we will continue to pursue transformative research to develop new medicines for people living with cancer.”
In March, Sanofi announced that the Phase 2 AMEERA-3 trial had not met the primary endpoint of improving progression-free survival in patients with ER+/HER2- advanced or metastatic breast cancer.