Drug Class: Cyclin-dependent kinases 4 and 6 (CDK4 and CDK6) Mechanism of Action Abemaciclib inhibits cyclin-dependent kinases 4 and 6 (CDK4 and CDK6), preventing them from promoting progression from G1 to S phase of the cell cycle. This can promote senescence, apoptosis, and reduced tumour size (1). Approved Indications Early breast cancer (1) Advanced or metastatic breast cancer (1) Mutated advanced or metastatic breast cancer (1) Dosage and administration Combination ther