Study: Elacestrant Prolongs Progression-Free Survival for ER+/HER2- Breast Cancer

The treatment also significantly reduces the risk of progression or death and prolonged median PFS compared with fulvestrant in all individuals without prior chemotherapy, the analysis shows.

The Menarini Group and Radius Health presented data from the EMERALD phase 3 clinical trial at the 2022 American Society of Clinical Oncology Annual Meeting.

Investigators found that elacestrant significantly prolonged progression-free survival (PFS) compared with the standard of care endocrine therapy in a non-pre-specific subgroup of individuals with ER+/HER2- metastatic breast cancer (mBC).

“Elacestrant is a potential exciting new endocrine therapy after progression on a CDK4/6 inhibitor in women with ER+ metastatic breast cancer. The EMERALD trial showed that elacestrant is active even in patients whose tumors harbor an ESR1 mutation,” Virginia Kaklamani, MD, breast medical oncologist and professor of medicine at UT Health San Antonio’s MD Anderson Cancer Center, said in the statement.

“This subset analysis additionally showed that patients who have not previously been treated with chemotherapy in the metastatic setting had longer progression free survival up to 5.32 months,” she said.

Additionally, the EMERALD study met both its pre-specified primary endpoints of PFS in individuals with ESR1 mutation and in the overall population.

Approximately 77.8% of individuals in the trial had not received prior chemotherapy in the metastatic setting for ER+/HER- mBC. Among these individuals, elacestrant demonstrated a 31% reduction in the risk of progression or death in all individuals and a prolonged median PFS of 3.68 months compared with 1.97 months with the standard-of-care therapy.

There was also a 46% reduction in the risk of progression or death in individuals with mESR1 and prolonged PFS at 5.32 months compared with 1.91 months with the standard-of-care therapy.

Additionally, at 6 months, the PFS rate with elacestrant was 38.18% compared with 23.47% with the standard of care in the overall population and 43.76% and 23.83%, respectively, in the ESR1 mutation population.

The PFS rate at 12 months with elacestrant was 27.12 and 12.19 with the standard of care in the overall population and 31.48% and 12.36%, respectively, in the ESR1 mutation population.

In the subgroup analyses, elacestrant also significantly reduced the risk of progression or death and prolonged median PFS compared with fulvestrant in all individuals without prior chemotherapy, with the median PFS being 3.68 months with elacestrant and 1.97 months with fulvestrant.

For individuals with mESR1 without prior chemotherapy, the median PFS was 5.32 and 1.91, respectively.

Elacestrant had a manageable safety profile in individuals without prior chemotherapy, and it was consistent with the overall population. The company plans to conduct combination studies to determine the potential of elacestrant and its effectiveness in addressing the highest unmet needs for individuals with ER+/HER2.

In 2018, elacestrant received fast track designation from the FDA.

Preclinical studies, prior to EMERALD, indicated that the drug has the potential for use as a single agent or in combination with other therapies for the treatment of breast cancer.

Reference

Menarini Group and Radius Health Inc present a subgroup analysis from the elacestrant pivotal phase 3 EMERALD clinical trial at the 2022 American Society of Clinical Oncology (ASCO) Annual Meeting. Radius. News release. June 6, 2022. Accessed June 7, 2022. Email.