Elacestrant Improves Outcomes for Certain Patients With Breast Cancer

Elacestrant met both primary endpoints of the EMERALD study, which included significant improvements to progression-free survival (PFS) in the overall study population and the estrogen receptor 1 (ESR1) mutation subgroup, according to the positive topline results of the study. The study was designed to evaluate elacestrant as a monotherapy compared to the standard of care (SoC) for the treatment of estrogen receptor-positive (ER-positive)/human epidermal growth factor receptor 2 (HER2-negative) advanced or metastatic breast cancer (mBC).

“We are extremely excited as elacestrant is the first oral SERD to show positive topline results in a pivotal trial as a monotherapy vs SoC for the treatment of ER-positive/HER2-negative advanced or mBC,” said Elcin Barker Ergun, chief executive officer of the Menarini Group, in a press release. “The results pave the way towards our working with the regulators to bring elacestrant to patients with ER-positive/HER2-negative advanced or metastatic breast cancer, which remains a huge unmet medical need. Notably, the topline results were also positive for the ESR1 mutation sub segment, an important driver of resistance to endocrine therapy in ER-positive/HER2-negative mBC patients. We intend to share the data at the San Antonio Breast Cancer Symposium in December.”

Elacestrant is a selective estrogen receptor degrader and the safety profile demonstrated in the phase 3 EMERALD trial was similar to the previous clinical trial for the drug. A total of 466 patients were enrolled in the study, 220 of whom had tumors harboring an ESR1 mutation. According to the investigators, ESR1 mutations drive the development of resistance to endocrine therapy in ER-positive/HER2-negative mBC patients.

“Advanced/metastatic ER-positive/HER2-negative breast cancer pre-treated with endocrine therapy remains an area of high unmet medical need,” said Aditya Bardia, MD, MPH of the MGH, associate professor at the Medicine Department at Harvard Medical School, in the release. “Additional therapeutic options for this patient population are urgently needed. The trial results being statistically significant demonstrate a clinically meaningful improvement of PFS in the elacestrant group versus endocrine standard of care in patients previously treated with endocrine therapies and CDK 4/6 inhibitors. The results provide a significant advancement for patients suffering from this devastating disease. It was also important to see the positive data for those patients with ESR1 mutations, known to confer additional resistance to standard endocrine therapy.”

A full evaluation of the results of the study is still ongoing. According to Radius Health, the current plan is to present data from the study at the San Antonio Breast Cancer Symposium in December 2021.

REFERENCE

Menarini Group and Radius Health announce positive phase 3 topline results from the EMERALD trial evaluating elacestrant in breast cancer [news release]. Globe Newswire; October 20, 2021. Accessed October 20, 2021.