Sanofi SA has terminated development of amcenestrant, an oral selective estrogen receptor degrader (SERD), following an interim analysis of data from a phase III trial in estrogen-receptor-positive advanced breast cancer patients. The company has also halted all other studies of the drug, including a phase III study in patients with early stage breast cancer.

Sanofi SA has suffered a setback in its bid to find a successor to Astrazeneca plc’s breast cancer drug Faslodex (fulvestrant) as amcenestrant failed to improve progression-free survival in advanced breast cancer in a mid-stage trial.

Sanofi SA is hoping an oral successor to Astrazeneca plc’s Faslodex (fulvestrant) could be a significant moneyspinner as it seeks to re-establish itself as a major player in oncology – and is pushing ahead with clinical trials to get it to market ahead of rivals. The Paris-based pharma has announced it is to start a new phase III trial of its second-generation oral selective estrogen receptor degrader (SERD) drug, amcenestrant, targeting high-risk patients with early breast cancer who need adjuvant drugs to suppress formation of secondary tumors after surgery.

Astrazeneca plc officials, during the firm’s Feb. 11 conference call on fourth-quarter earnings, highlighted the oral selective estrogen receptor degrader (SERD) camizestrant in breast cancer (BC), which Cristian Massacesi, head of late-stage oncology development, said bears “best-in-class potential, in terms of providing superior clinical benefit at a well-tolerated dose” of 75 mg once per day.