birociclib + rifampicin

Birociclib (XZP-3287) is an orally bioavailable, highly selective small molecule inhibitor of cyclin-dependent kinases 4 and 6 (CDK4/6), developed by Xuanzhu Biopharmaceutical for the treatment of hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) breast cancer. It works by inhibiting the CDK4/6-cyclin D complex, preventing the phosphorylation of the retinoblastoma (Rb) protein and arresting the cell cycle in the G1 phase. This specific combination involves the co-administration of birociclib with rifampicin, a potent inducer of the CYP3A4 enzyme and an inhibitor of bacterial DNA-directed RNA polymerase. This combination is primarily used in Phase I clinical trials to conduct drug-drug interaction (DDI) studies, evaluating how the induction of metabolic enzymes by rifampicin affects the pharmacokinetics, safety, and tolerability of birociclib in healthy subjects.

Other names

XZP-3287 + rifampicin