Ibraciclib

Ibraciclib is a small molecule inhibitor of cyclin-dependent kinases 4 and 6 (CDK4/6), developed and marketed by Pioneer Pharma as a generic version of palbociclib. It functions by selectively inhibiting the CDK4 and CDK6 enzymes, which are downstream of multiple signaling pathways that lead to cellular proliferation. By blocking these kinases, Ibraciclib prevents the phosphorylation of the retinoblastoma (Rb) protein, thereby arresting the cell cycle in the G1 phase and inhibiting DNA synthesis. This mechanism is particularly effective in treating hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced or metastatic breast cancer, where it is typically used in combination with endocrine therapies such as aromatase inhibitors or fulvestrant.

Brand names

Ibraciclib

Other names

palbociclib