Sanofi Abandons SERD Candidate After Second Breast Cancer Clinical Trial Blow

Following an interim analysis of the Phase 3 AMEERA-5 trial, Sanofi announced it is ending its development program for amcenestrant, a once-promising selective estrogen receptor degrader (SERD) designed to treat ER+/HER2- advanced breast cancer. The nail in the coffin followed an announcement in March stating that the drug did not meet primary endpoints in a monotherapy Phase 2 trial either. 

Dashed Hopes of a Once Optimistic Prospect

Sanofi is one of many companies that jumped at the opportunity to develop a SERD candidate amidst the resurging interest in the field. Alongside companies like Roche, Novartis, and Eli Lilly, Sanofi sought to develop amcenestrant, an oral SERD that would maintain the efficacy of the only approved SERD, Faslodex, without the painful injections that the current option entails.

While early development showed promise, the French biotech started running into issues in later-stage clinical trials. The Phase 2 AMEERA-3 clinical trial studying amcenestrant as a monotherapy to treat ER+/HER2- breast cancer did not meet its primary endpoint of progression-free survival compared to other endocrine treatments prescribed by physicians. Despite the hiccup, Sanofi vowed to continue other clinical trials studying the drug in various combination therapies. 

Now, amcenestrant is not fairing any better in the clinic, even in combination therapies. The Phase 3 AMEERA-5 clinical trial studies amcenestrant in combination with palbociclib compared to letrozole in combination with palbociclib and is still not on track to meet its goals to continue the study. As a result of the failure, Sanofi is officially pulling the drug from its pipeline. 

Global Head of Research and Development at Sanofi, John Reed, MD, Ph.D., said, “While we are disappointed by this outcome, our research will further the scientific understanding of endocrine therapies in people with breast cancer.” 

Related Article: Gilead’s New Chemotherapy for Metastatic Breast Cancer Demonstrates Increase in Overall Survival

The Rest of the Industry’s Efforts to Develop Effective SERDs

Sanofi is not the only company struggling in SERD development. In April, Roche announced in an investor update that its SERD candidate, giredestrant, did not meet its primary endpoints in a Phase 2 trial. The Swiss company says it would continue the development program in hopes that the drug will provide a niche for patients who exhibit a higher dependence on estrogen receptor activity. 

More hopeful prospects in the arena include Menarini and Radius Health Group’s jointly developed elacestrant. The two companies submitted their SERD candidate for a New Drug Application (NDA) to the FDA in June and are hoping for a Priority Review, which would provide a judgment within eight months. 

AstraZeneca’s camizestrant is also in Phase 3 trials to treat breast cancer as a first-line treatment. The company anticipates that data will be available from the SERENA-4 and SERENA-6 trials sometime in 2023. 

While Sanofi’s most recent announcement to halt the development of amcenestrant is disappointing, several others in the industry are forging ahead in various SERD development programs. With quite a bit of momentum behind the technology, hopefully, a few companies will be able to prove their worth in the coming years, providing a much-desired new treatment option for breast cancer patients. 

Author

Reed Slater