Cabazitaxel is a microtubule inhibitor. Cabazitaxel binds to tubulin and promotes its assembly into microtubules while simultaneously inhibiting disassembly. This leads to the stabilization of microtubules, which results in the inhibition of mitotic and interphase cellular functions.
After an intravenous dose of cabazitaxel 25 mg/m2 every three weeks to a population of 170 patients with solid tumors, the mean Cmax in patients with metastatic prostate cancer was 226 ng/mL (CV 107%) and was reached at the end of the one-hour infusion (Tmax). The mean AUC in patients with metastatic prostate cancer was 991 ng.h/mL (CV 34%).
Cabazitaxel is extensively metabolized in the liver (>95%), mainly by the CYP3A4/5 isoenzyme (80% to 90%), and to a lesser extent by CYP2C8. Cabazitaxel is the main circulating moiety in human plasma. Seven metabolites were detected in plasma (including the 3 active metabolites issued from O-demethylation), with the main one accounting for 5% of cabazitaxel exposure.
Cabazitaxel may cause serious side effects including neutropenia, hypersensitivity reactions, gastrointestinal symptoms, and renal failure. Anticipated complications of overdose include exacerbation of adverse reactions such as bone marrow suppression and gastrointestinal disorders. Cabazitaxel penetrates the blood-brain barrier.