Lilly – a pharmaceutical company that invests in research and development to improve people’s lives and health – informs about the positive results of a new drug, demonstrated in the Study MonarchE of phase 3.
According to the results of the clinical trial, after two years of adjuvant treatment with the CDK4/6i-class molecule, combined with endocrine therapy, in high-risk HR+, HER2, early breast cancer, the risk of recurrence was reduced and the survival rate was improved.
The CDK4/6i class molecule is a drug discovered and developed by Lilly researchers and was first approved in 2017 by the Food and Drug Administration (FDA). Currently, the drug is authorized for use in over 90 countries around the world, including Romania.
MonarchE is a global clinical trial that enrolled 5,637 adults (from more than 600 centers in 38 countries) with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-), lymph node-positive early breast cancer and high risk of recurrence.
Through this study, important data were revealed about this therapy associated with endocrine therapy, improving the survival time and the quality of life of the patients.
According to the MonarchE Study, from the analysis of the data reported at seven years, adjuvant treatment with the new drug, in combination with endocrine therapy (ET) for a duration of two years, demonstrated positive results – reduction of the risk of death; sustained long-term (seven years) improvements in survival rates in the absence of invasive disease; absence of distant recurrence in patients with hormone-dependent early breast cancer and HER2 negative and high risk of recurrence – as follows:
ü in the population of Cohort 1, the new drug associated with endocrine therapy reduced the risk of death by 16.5% compared to ET monotherapy;
ü treatment with the CDK4/6i class molecule and ET resulted in a significant reduction in the risk of recurrence at seven years, continuing to demonstrate a real benefit in terms of invasive disease-free (IDFS) and distant recurrence-free (DRFS) survival;
ü the number of patients with metastatic disease who received treatment with this drug and ET was 33% lower than those who received only ET monotherapy (6.5% vs. 9.7%);
ü adverse effects were generally managed with dose adjustments consistent with previous MonarchE analyses.
These results were published in the journal Annals of Oncology and presented at the Annual Meeting of the European Society of Medical Oncology, held in Berlin on 17 October 2025.
About early breast cancer and the risk of recurrence
Estimates show that in developed countries where screening programs are in place, 90% of all breast cancer cases are detected at an early stage and about 70% of all breast cancer cases are HR+, HER2-.
Although the prognosis for HR+, HER2- early breast cancer is generally favorable, high-risk patients are three times more likely (than low-risk) to experience a recurrence – most cases being diagnosed with incurable metastatic disease. These patients present an increased risk of relapse during the first two years of endocrine therapy.
According to GLOBOCAN (The Global Cancer Observatory), breast cancer is the second most commonly diagnosed cancer globally (after lung cancer). The estimated 2.3 million new cases indicate that nearly 1 in 4 cancers diagnosed in 2022 is breast cancer, and with an estimated 666,000 deaths in 2022, it is the fourth leading cause of cancer death worldwide.
Note: This document is addressed to media representatives and is strictly informative about innovation in the pharmaceutical field, not promotional or educational material. The medicine is only available on the basis of a medical prescription and must be prescribed and administered to patients only by health professionals, in the Oncology specialty, according to the prescription protocol.
Article supported by Lilly
