Sanofi drops, as it abandons amcenestrant clinical development program

Shares of French pharma major Sanofi (Euronext: SAN) were down 4.8% at 82.42 euros this morning, after it announced the discontinuation of 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 III AMEERA-5 trial evaluating amcenestrant in combination with palbociclib compared with letrozole in combination with palbociclib, Pfizer’s (NYSE: PFE) Ibrance, 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.