Verzenio (abemaciclib) prolonged survival in HR+, HER2-, high-risk early breast cancer with two years of treatment – Eli Lilly

Eli Lilly and Company announced results from the primary overall survival (OS) analysis of the Phase III monarchE trial showing that two years of adjuvant Verzenio plus endocrine therapy (ET) reduced the risk of death by 15.8% versus ET alone and resulted in sustained long-term improvements in invasive disease-free survival (IDFS) and distant relapse-free survival (DRFS), in patients with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-), node-positive, high-risk early breast cancer.

These results were published in the Annals of Oncology and were shared in a late-breaking oral presentation at the ESMO Annual Meeting in Berlin, Germany. These data are being submitted to regulatory health authorities globally.

“For patients, survival is what matters most — and abemaciclib plus endocrine therapy represents the first contemporary medicine in over two decades to deliver a clear improvement in overall survival in the adjuvant setting,” said Stephen Johnston, M.D., Ph.D., Professor of Breast Cancer Medicine and Consultant Medical Oncologist at The Royal Marsden NHS Foundation Trust (London, U.K.) and lead investigator for monarchE. “These results represent an important step forward in the treatment of high-risk HR+, HER2− early breast cancer.”

The data presented include results from the primary OS analysis reflecting a median follow-up of 6.3 years, with more than 75% of patients having been followed for at least four years after completion of the two-year Verzenio treatment period. In the intent-to-treat (ITT) population, Verzenio plus ET reduced the risk of death by 15.8% compared to ET alone [7-year overall survival (OS) rate: 86.8% vs. 85.0%; hazard ratio (HR) 0.842; 95% CI: 0.722–0.981; 2-sided p=0.027].

In addition, treatment with Verzenio plus ET led to a sustained reduction in risk of recurrence at seven years, continuing to demonstrate the deep IDFS and DRFS benefit and carryover effect previously seen at five years in monarchE. Notably, 32% fewer patients treated with Verzenio plus ET were living with metastatic disease compared to those receiving ET alone (6.4% vs 9.4%, respectively). Continued long-term follow-up from this trial will help to determine whether this ongoing difference in patients alive with metastatic disease translates into further deepening of survival benefit with time. Results for Cohort 1 were consistent with those for the ITT population across OS, IDFS and DRFS results, and the benefit was also demonstrated across subgroups.

“These results represent an important advancement in the care of node-positive, high-risk HR+, HER2- disease by delivering meaningful reductions in recurrence and improving survival,” said Jacob Van Naarden, executive vice president and president of Lilly Oncology. “These findings reinforce two years of Verzenio plus endocrine therapy as the standard of care for node-positive, high-risk disease, offering renewed hope for patients facing this diagnosis.”

Safety findings were consistent with the known profile of Verzenio and prior monarchE analyses. No new safety signals or delayed toxicities were observed. Adverse events were generally managed with dose modifications, consistent with prior monarchE analyses.

“For patients facing high-risk early breast cancer, these results are meaningful,” said Sue Weldon, CEO of Unite for HER. “To now have data showing a treatment helps more people live longer is a major step forward for our community. We mark this significant milestone while recognizing there’s more work ahead to ensure every eligible patient has the opportunity to benefit from treatments that can change lives.”

About the monarchE Study
monarchE was a global, randomized, open-label, two cohort, multicenter Phase III clinical trial that enrolled 5,637 adults with HR+, HER2-, node-positive EBC at high risk of recurrence. The study enrolled patients across more than 600 sites in 38 countries and is the only adjuvant study designed to investigate a CDK4/6 inhibitor specifically in a node-positive, high-risk EBC population. To be enrolled in Cohort 1 (n=5,120), which is the FDA-approved population, patients had to have 4+ positive nodes or 1-3 positive nodes and at least one of the following: tumors that were ≥5 cm or Grade 3. Patients enrolled in Cohort 2 could not have met the eligibility criteria for Cohort 1. To be enrolled in Cohort 2 (n=517), patients had to have 1-3 positive nodes and Ki-67 score ≥20%. Patients in each cohort were randomized 1:1 to receive either Verzenio 150 mg twice daily plus standard-of-care adjuvant ET (Cohort 1, n=2,555; Cohort 2, n=253) or standard-of-care adjuvant ET alone (Cohort 1, n=2,565; Cohort 2, n=264) for 2 years. ET continued for at least 5 years if deemed medically appropriate. The primary endpoint was IDFS. Consistent with expert guidelines, IDFS was defined as the length of time before breast cancer comes back, any new cancer develops, or death. OS was a key secondary endpoint in monarchE. The OS analysis plan was amended after the primary analysis of IDFS, following consultation with regulators, to increase the number of required OS events from 390 to 650 to ensure a minimum follow-up of at least 5 years and enable a more mature survival dataset.

Citation: Overall Survival with Abemaciclib in Early Breast Cancer. Authors: S. Johnston ∙ M. Martin ∙ J. O’Shaughnessy et al. Annals of Oncology. Published online October 17, 2025. DOI: 10.1016/j.annonc.2025.10.005