• lacestrant, if approved, would be the first oral selective estrogen receptor degrader (SERD) to be available for patients suffering from second-line (2L) and third-line (3L) ER+/HER2- advanced or metastatic breast cancer in the European Union
• Submission supported by results from the pivotal Phase 3 EMERALD study showing a statistically significant difference in the efficacy in favor of elacestrant over current standard-of-care (SOC) medications for both the overall study population and patients whose tumors harbor an ESR1 mutation

The Menarini Group ("Menarini"), a privately held Italian pharmaceutical and diagnostics company, and Stemline Therapeutics ("Stemline"), a wholly-owned subsidiary of the Menarini Group, today announced that EMA has validated the Marketing Authorization Application (MAA) for elacestrant, a selective estrogen receptor degrader (SERD), for patients with ER+/HER2- advanced or metastatic breast cancer. Validation of the application confirms the submission is complete and begins EMA's centralized review procedure.

"There is a major unmet need in the treatment of advanced or metastatic ER+/HER2- breast cancer after resistance builds in the earlier lines of treatment" commented Elcin Barker Ergun, Chief Executive Officer of the Menarini Group. "The acceptance of our application for review by the EMA represents a significant step for our company and we look forward to working with the agency to potentially bring elacestrant to patients suffering from second and third line ER+/HER2- advanced or metastatic breast cancer in Europe."

The Phase 3 EMERALD study (NCT03778931) evaluated elacestrant compared to SOC endocrine monotherapy (investigators' choice of either fulvestrant or an aromatase inhibitor) in ER+/HER2- advanced or metastatic breast cancer patients. The study results were recently published online in the Journal of Clinical Oncology (JCO) on May 18, 2022. Further post-hoc analysis from the study will be presented at the European Society for Medical Oncology (ESMO) Congress 2022 taking place September 9-13, 2022, in Paris, France.

The Menarini Group obtained global licensing rights for elacestrant in July 2020 from Radius Health, Inc, who conducted and successfully completed the EMERALD study. Based on the positive phase 3 data, Stemline submitted a MAA to EMA on July 27, 2022. The regulatory review for elacestrant is also underway in the US as the Food and Drug Administration (FDA) has recently accepted a new drug application for elacestrant designating a priority review. The Menarini Group is now fully responsible for global registration, commercialization and further development activities for elacestran