Researchers from Mayo Clinic have collaborated on a new study demonstrating that the drug abemaciclib improves survival for people with early-stage, high-risk breast cancer. In the phase 3 monarchE clinical trial, two years of treatment with abemaciclib (Verzenio®), in combination with endocrine therapy, reduced the risk of death by 15.8% compared to endocrine therapy used alone among patients with a common type of early-stage breast cancer. The clinical trial included more than 5,600 patients in over 600 research centers across 38 countries. All participants had hormone receptor-positive (HR+) and human epidermal growth factor receptor 2-negative (HER2-) breast cancer, a subtype that accounts for 70% of all breast cancers, and also had cancer in at least one axillary lymph node, a factor associated with a higher risk of recurrence. "This is the first therapy to significantly prolong the survival of this patient population in over two decades," says study co-author Matthew Goetz, M.D., a breast clinical oncologist at Mayo Clinic's Comprehensive Cancer Center. This confirms that abemaciclib helps reduce the risk of recurrence, even after the drug treatment has been completed. Continued follow-up will determine if the survival benefit extends over time. These findings, published in Annals of Oncology, establish abemaciclib in combination with endocrine therapy as the new standard of treatment for this high-risk group. Abemaciclib is a CDK4/6 inhibitor, a type of drug that blocks proteins involved in the division of cancer cells. "Now we can state with confidence that the benefits observed initially, in terms of reducing recurrences, translate into an improvement in survival, which is what matters most to patients," says Dr. Goetz. "With the addition of a single drug to the standard endocrine therapy, we are not only seeing fewer recurrences, but we are also reducing the likelihood of death from breast cancer."
