Adding the CDK4/6 inhibitor Kisqali (ribociclib) to hormone therapy after surgery reduced the risk for recurrence by 25% for people with early to mid-stage breast cancer.

The Phase III NATALEE trial included 5,101 premenopausal or postmenopausal women and a few men with Stage II or III hormone receptor-positive/HER2-negative breast cancer that was considered at risk for recurrence. After surgery, they were randomly assigned to receive adjuvant hormone therapy with or without Kisqali. Those who added the targeted therapy saw a significant improvement in invasive disease-free survival, meaning their cancer did not relapse and spread.

“These landmark results will fundamentally change how we treat patients with Stage II and III HR-positive/HER2-negative early breast cancer who are in need of new, well-tolerated options that prevent their cancer from coming back,” said lead investigator Dennis Slamon, MD, PhD, of UCLA.