Eli Lilly and Company (NYSE: LLY) announced results from the Phase 3 EMBER-3 study of imlunestrant, an investigational, oral selective estrogen receptor degrader (SERD), in patients with estrogen receptor positive (ER+), human epidermal growth factor receptor 2 negative (HER2-) advanced breast cancer (ABC), whose disease progressed on a prior aromatase inhibitor (AI), with or without a CDK4/6 inhibitor. Imlunestrant demonstrated a statistically significant and clinically meaningful improvement in progression-free survival (PFS) as monotherapy in patients with an ESR1 mutation versus standard of care endocrine therapy (SOC ET), reducing the risk of disease progression or death by 38%. Imlunestrant in combination with Verzenio (abemaciclib; CDK4/6 inhibitor) reduced the risk of progression or death by 43% versus imlunestrant alone, in all patients.

These results were published in The New England Journal of Medicine and will be shared in a late-breaking oral presentation at the San Antonio Breast Cancer Symposium (SABCS) today, Wednesday, December 11 at 9:15 AM CT/10:15 AM ET. These data are being submitted to regulatory health authorities globally.

"The median progression free survival observed in EMBER-3 is among the most compelling we've seen in CDK4/6 pre-treated ER+, HER2- advanced breast cancer patients and indicates a potential shift in the therapy options we provide for these patients, which are currently very limited," said Komal Jhaveri, M.D., section head, endocrine therapy research and clinical director, early drug development at Memorial Sloan Kettering Cancer Center, and one of the study's principal investigators. "The benefit and safety profile of the imlunestrant and abemaciclib combination signal a potential new all-oral option for patients."

In the EMBER-3 study, patients were randomized 1:1:1 to receive imlunestrant alone, SOC ET, or the imlunestrant-abemaciclib combination. Randomization was stratified by prior CDK4/6 inhibitor use, the presence of visceral metastases and geographic region. Patients enrolled as first line (1L) treatment for ABC (32%), following disease recurrence on or within 12 months of completing adjuvant AI, with or without CDK4/6 inhibitor for early breast cancer (EBC), or as second line (2L) treatment for ABC (64%), following progression on AI, with or without CDK4/6 inhibitor as initial therapy for ABC. Primary endpoints were investigator-assessed PFS of imlunestrant versus SOC ET therapy in patients with ESR1 mutations, imlunestrant versus SOC ET in all patients, and imlunestrant-abemaciclib versus imlunestrant in all patients.