Elacestrant is oral therapy that targets estrogen receptor 1, a key resistance mechanism in advanced breast cancer.
Menarini Group and Radius Health have submitted a new drug application (NDA) to the FDA for elacestrant in patients with ER+/HER2- advanced or metastatic breast cancer. The companies are requesting priority review.
If approved, elacestrant it would be the first oral therapy in a class of medications called selective estrogen receptor degraders (SERDs), which binds to the estrogen receptor and causes it to be downregulated. As a result, SERDs are being studied in breast cancers that have become resistant to aromatase inhibitors or those with tamoxifen resistance.
AstraZeneca’s Faslodex (fulvestrant) was the first SERD to be approved by the FDA in 2017. It is an injection therapy for patients with estrogen receptor positive breast cancer.
“We are excited about the potential for elacestrant to be approved for treatment of patients with advanced or metastatic ER+/HER2- breast cancer, which constitutes about 70% of breast cancer and remains an area of significant unmet medical need,” Elcin Barker Ergun, the chief executive dfficer of Menarini, said in a press release.
The elacestrant submission is based on positive phase 3 data from the EMERALD study, which showed that elacestrant met both of its primary endpoints, which were progression-free survival in the overall population and progression-free survival in the estrogen receptor 1 (ESR1) mutation subgroup compared with standard of care with the options of (Faslodex) fulvestrant or an aromatase inhibitor.
In the study, among those who received elacestrant, there was a 31% reduction in the risk of progression or death and a prolonged median progression-free survival of 3.68 months compared 1.97 months in patients receiving standard of care. There was also a 46% reduction in the risk of progression or death in patients with a mutation of ESR1 and prolonged median progression-free survival of 5.32 months compared 1.91 months for those in the standard of care group. ESR1 mutation is one of the key resistance mechanisms that develops in later treatment lines of metastatic breast cancer.