Abemaciclib Significantly Improves Overall Survival in High-Risk Early Breast Cancer

The CDK4/6 inhibitor abemaciclib (Verzenio) has demonstrated a statistically significant improvement in overall survival (OS) when administered for 2 years in combination with endocrine therapy (ET) to patients with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2–), node-positive, high-risk early breast cancer.¹

Further, the 7-year analysis shows a long-term benefit in disease-free survival DFS) and distant relapse-free survival (DRFS). These positive topline results from the phase 3 monarchE trial (NCT03155997) further solidify abemaciclib’s role as a standard of care in this patient population. The full data will be presented at an upcoming medical meeting and shared with regulatory authorities.

The monarchE trial is a global, randomized, open-label, multicenter study that enrolled 5,637 adults with HR+, HER2– early breast cancer who were at high risk of recurrence.^1,2 Patients were randomized to receive either 2 years of abemaciclib at a dose of 150 mg twice daily plus standard-of-care adjuvant ET or ET alone. The primary end point of the trial was DFS with OS as a key secondary end point.

Previous analyses of the trial have already established abemaciclib's role in significantly reducing the risk of recurrence and distant relapse, a benefit that has been shown to persist beyond the 2-year treatment period.¹

According to Jacob Van Naarden, executive vice president and president of Lilly Oncology, in a press release, "Achieving a statistically significant OS benefit with just 2 years of abemaciclib therapy reinforces its differentiated profile in high-risk HR+, HER2– early breast cancer. These data validate [abemaciclib] as the standard-of-care for patients with node-positive, high-risk disease and increase the urgency to ensure all eligible patients are treated."

The patient population in the monarchE trial was defined by high-risk clinical and pathological features, including positive nodal status (4+ positive nodes, or 1–3 positive nodes with a large tumor size [≥5 cm] or high tumor grade [Grade 3]). The trial is the only adjuvant study to specifically investigate a CDK4/6 inhibitor in this high-risk population, and its design has been widely considered practice changing.

The safety profile of abemaciclib in this latest analysis remained consistent with previous reports from the trial. No new safety signals emerged during the course of treatment. The most commonly reported adverse events were diarrhea and neutropenia, which are consistent with the known safety profile of abemaciclib from prior studies in both the adjuvant and metastatic settings. The majority of these adverse events were grade 1 or 2, with dose adjustments helping to manage higher-grade reactions, allowing patients to continue therapy and complete the 2-year treatment regimen.

FAQs

What is abemaciclib and what is its primary use in breast cancer treatment?

Abemaciclib (Verzenio) is a CDK4/6 inhibitor. Its primary use, as demonstrated by the monarchE trial, is in combination with endocrine therapy (ET) for patients with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2–), node-positive, high-risk early breast cancer. It has been shown to significantly improve overall survival (OS) in this specific patient population.

What are the key benefits of abemaciclib in treating high-risk early breast cancer?

Abemaciclib has demonstrated several key benefits: it significantly improves overall survival (OS), disease-free survival (DFS), and distant relapse-free survival (DRFS). These benefits have been shown to persist long-term, even beyond the initial 2-year treatment period, reducing the risk of recurrence and distant relapse.

This article was generated with assistance from Google Gemini and NotebookLM. It was edited and reviewed by Targeted Oncology staff. If you have any questions about the use of AI, please contact us.

REFERENCES:

1. Lilly's Verzenio® (abemaciclib) increases overall survival in HR+, HER2-, high-risk early breast cancer with two years of therapy. News release. Eli Lilly. August 27, 2025. Accessed August 28, 2025. https://tinyurl.com/yu6n2f5f

2. Endocrine Therapy With or Without Abemaciclib (LY2835219) Following Surgery in Participants With Breast Cancer (monarchE). ClinicalTrials.gov. Updated April 20, 2025. Accessed August 28, 2025. https://clinicaltrials.gov/study/NCT03155997