ESMO: Lilly reveals scale of survival win with Verzenio

Eli Lilly's CDK4/6 inhibitor Verzenio reduced the risk of death by 15.8% when used as adjuvant treatment for early-stage HR-positive, HER2-negative breast cancer, according the reveal of data from the monarchE trial.

The results – presented at the ESMO cancer congress and simultaneously published in Annals of Oncology – come after seven years of follow-up of patients in monarchE and show a clear overall survival (OS) benefit of adding two years of Verzenio (abemaciclib) treatment to standard endocrine therapy in this population.

The OS rate at that timepoint was 86.8% versus 85% for patients treated with endocrine therapy alone, which Lilly said was "clinically meaningful." The data also showed that 6.4% of patients taking Verzenio had developed metastatic disease at seven years, compared to 9.4% of those on endocrine therapy alone, which was a 32% reduction.

The results will be used as the basis of regulatory filings to extend the label for Verzenio and could be important in helping Lilly keep its drug ahead of fast-growing rival Kisqali (ribociclib) from Novartis in the market.

Verzenio has been approved for use alongside endocrine therapy for patients with early HR-positive, HER2-negative breast cancer that has spread to the lymph nodes since 2021, based on invasive disease-free survival data (iDFS) from monarchE, and that has helped propel sales to more than $5 billion a year.

Kisqali has encroached on its territory, however, and an FDA approval last year – based on the NATALEE trial – gave it a broader label in early-stage HR+/HER2- breast cancer that included node-negative as well as node-positive patients. Sales reached $3 billion in 2024, but the new indication led to a growth spurt, rising 60% to $2.1 billion in the first half of 2025.

Kisqali hasn't been able to achieve an increase in OS in NATALEE, and Lilly maintains that Verzenio is "the first contemporary therapy in over two decades" to reduce the risk of death in this type of cancer.

"For patients, survival is what matters most," commented monarchE's lead investigator Stephen Johnston of The Royal Marsden NHS Foundation Trust in the UK. "These results represent an important step forward in the treatment of high-risk HR+, HER2− early breast cancer."

Novartis did report some new data with Kisqali at ESMO, namely five-year results from NATALEE, which showed a 28.4% reduction in risk of recurrence in "the broadest population of patients" with this type of cancer.

It said OS "continues to show an encouraging trend" in the trial, with a 20% improvement compared to endocrine therapy alone, bigger than the 11% gain seen at three years, which might suggest it will become significant with further follow-up.

Commenting on the monarchE results, ESMO rapporteur Angela DeMichele from the University of Pennsylvania said that Verzenio's OS benefit is welcome, but the "absolute difference in OS between treatment arms is modest and the larger benefit appears to be in preventing relapse."

"This is good news for patients in whom the priority is to avoid metastatic disease, but the discrepancy between relapse-free survival and OS requires longer follow-up and raises important questions about the impact of receiving adjuvant abemaciclib on post-relapse outcomes," she added.