Kisqali (generic name: ribociclib) is a prescription medicine that belongs to the class of cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors. It works by blocking CDK4/6 proteins, which drive cancer cell growth and division. By inhibiting these pathways, Kisqali helps slow down or stop the progression of hormone receptor (HR)–positive, HER2-negative breast cancer.

It is indicated for use in combination with an aromatase inhibitor or fulvestrant as initial endocrine-based therapy, or after disease progression, in postmenopausal women and adult men with HR-positive, HER2-negative advanced or metastatic breast cancer.

Kisqali is taken orally, usually once daily in cycles (3 weeks on treatment, 1 week off). Common side effects include neutropenia, fatigue, nausea, rash, and potential QT prolongation, which requires monitoring.