The Menarini Group, an Italian pharmaceutical and diagnostics company, says that the U.S. Food and Drug Administration (FDA) has approved ORSERDU for the treatment of postmenopausal women or adult men, with ER+, HER2-, ESR1-mutated advanced or metastatic breast cancer with disease progression following at least one line of endocrine therapy.
Stemline Therapeutics, a wholly-owned subsidiary of the Menarini Group, headquartered in New York and focused on bringing transformational oncology treatments for cancer patients, will commercialize ORSERDU in the U.S.
“The FDA approval of ORSERDU marks the first ever therapy for ER+, HER2- advanced or metastatic breast cancer patients with ESR1 mutations and we are very proud to offer a targeted therapy addressing this huge unmet need,” said Elcin Barker Ergun, chief executive officer of the Menarini Group.
“We are grateful to the patients, investigators and administrators who participated in the clinical trials that led to this remarkable innovation.”
Endpoints met for Stemline Therapeutics’ treatment
ORSERDU is approved under the FDA’s Priority Review and Fast Track designation based on the results of the phase III trial EMERALD, which demonstrated statistically significant progression-free survival (PFS) with elacestrant compared to standard of care (SOC) endocrine monotherapy (fulvestrant, letrozole, anastrozole, exemestane), meeting both primary endpoints in all patients and in those patients whose tumors harbor ESR1 mutations.
In the group of patients whose tumors had ESR1 mutations, elacestrant reduced the risk of progression or death by 45% compared to SOC. A post-hoc analysis of the PFS results based on the duration of prior CDK4/6i inhibitors (CDK4/6i) usage was presented at the San Antonio Breast Cancer Symposium (SABCS) in December 2022. The median PFS was 8.6 months on elacestrant vs 1.9 months for SOC, in those patients whose tumors harbored ESR1 mutations and had been treated with a CDK4/6i for at least 12 months.
Safety data is consistent with the other endocrine therapies. Most of the adverse events (AEs), including nausea and musculoskeletal pain, were grade 1 and 2. No hematological safety signal was observed and none of the patients in either of the two treatment arms had sinus bradycardia.
Novel option for patients
“Advanced or metastatic ER+, HER2- breast cancer pre-treated with endocrine-based therapy remains an area of unmet medical need. The last endocrine therapy approved was about 20 years ago, and effective endocrine options for this patient population are needed,” said Aditya Bardia, director of Breast Cancer Research at Mass General Cancer Center, associate professor at the Medicine Department at Harvard Medical School, and principal investigator for the EMERALD trial.
“ESR1 mutations are a known driver of resistance to standard endocrine therapy, and so far, have been difficult to treat. The approval of elacestrant is welcomed as it offers a novel option for patients with ER+, HER2- metastatic breast cancer. This therapy targets the ESR1 mutations in metastatic breast cancer and provides patients with a convenient oral once-daily dose.”
The Menarini Group obtained global licensing rights for elacestrant in July 2020 from Radius Health, Inc., which conducted the EMERALD study. With this approval, Radius will receive milestone payments and royalties from commercial sales. The Menarini Group is now fully responsible for global registration, commercialization, and further development activities for elacestrant.
Elacestrant is also being investigated in several clinical trials in metastatic breast cancer disease, alone or in combination with other therapies: ELEVATE; ELECTRA; ELONA; and ELCIN. Elacestrant is also planned to be evaluated in early breast cancer disease.