• Intended for potential treatment of ER+/HER2- advanced or metastatic breast cancer patients
• Priority Review requested; if accepted, anticipate an 8-month FDA review
• Positive EMERALD study data previously announced on October 20, 2021
• First, and currently only, investigational oral SERD with positive topline results
• Additional data presented at SABCS (December 2021) and ASCO (June 2022)
• Plan to file marketing authorization application for elacestrant in the EU in 2H 2022

As part of the submission, the Companies have requested Priority Review with the FDA. If Priority Review is granted, the Companies anticipate that the FDA would conduct an 8-month review, incorporating a 6-month priority designation review.

The NDA submission is based on positive phase 3 data from the EMERALD study that was previously announced on October 20, 2021. EMERALD met both of its primary endpoints, which were progression-free survival (PFS) in the overall population and PFS in the estrogen receptor 1 (ESR1) mutation subgroup as compared to standard of care (SoC) with the options of fulvestrant or an aromatase inhibitor.

Elacestrant is the first and currently only investigational oral SERD to show positive topline results in a pivotal trial for the treatment of ER+/HER2- advanced or metastatic breast cancer in postmenopausal women, and men. Notably, these results showed elacestrant is also active in patients whose tumors harbor an ESR1 mutation, one of the key resistance mechanisms that develops in later treatment lines of metastatic breast cancer.

Following the completion of EMERALD, data from the study was presented at the San Antonio Breast Cancer Symposium (SABCS) on December 8, 2021, published in the Journal of Clinical Oncology (JCO) on May 18, 2022, and further subset analyses were presented at the 2022 American Society of Clinical Oncology (ASCO) annual Meeting on June 6, 2022.

Elcin Barker Ergun, the Chief Executive Officer of Menarini, commented, "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." Barker Ergun continued, "Elacestrant has shown statistically significant efficacy over current standard of care medications both for overall population and in patients whose tumors harbor an ESR1 mutation, one of the most difficult to treat mechanisms of acquired resistance that develops in the later stages of metastatic/advanced breast cancer."

Chhaya Shah, SVP of Clinical and Regulatory at Radius, commented, "We enrolled and completed the EMERALD trial in a high-quality manner, delivered positive topline results, and prepared the submission of the NDA to the FDA. The submission is a significant milestone for both companies, and we appreciate the strong, collaborative effort of many hard-working employees at Radius and Menarini, investigators, patients, and their families. Together we look forward to advancing elacestrant and providing the opportunity to benefit patients."

Nassir Habboubi, Global Head of Pharma R&D of Menarini Group, added, "The Menarini and Radius teams have done an excellent job working together since our partnership began in July of 2020." Habboubi continued, "We plan to test elacestrant in earlier treatment lines, combination trials, and metastatic breast cancer that has metastasized to the brain. These details are to be communicated by us throughout 2H 2022 and 1H 2023."

With the submission of the NDA, based on the original agreement of the Companies, Menarini takes over activities and will be responsible for registration and commercialization. Menarini plans to use its fully owned subsidiary in the U.S., Stemline Therapeutics, to commercialize elacestrant if approved by the FDA.