• KEYNOTE-756 explores chemoimmunotherapy's role in high-risk HR-positive, HER2-negative breast cancer, showing improved pathologic complete response rates, but event-free survival data is pending.
• The FDA approved adjuvant ribociclib based on the NATALEE trial, broadening CDK4/6 inhibitor eligibility to include lower-risk patients with HR-positive, HER2-negative breast cancer.
• MonarchE trial data supports adjuvant abemaciclib for high-risk patients, demonstrating a 6% absolute difference in invasive disease-free survival, but diarrhea management is crucial.
• Treatment decisions now involve navigating side effect profiles, therapy duration, and individual risk factors when choosing between abemaciclib and ribociclib for eligible patients.