PubMed | c Chugai Pharmaceuticals Co., f d3 Medicine, Hoffmann-La Roche and d Chugai Pharmaceutical Co.
Type: | Journal: Xenobiotica; the fate of foreign compounds in biological systems | Year: 2016
1.Alectinib is a highly selective, central nervous system-active small molecule anaplastic lymphoma kinase inhibitor. 2.The absolute bioavailability, metabolism, excretion and pharmacokinetics of alectinib were studied in a two-period single-sequence crossover study. A 50g radiolabelled intravenous microdose of alectinib was co-administered with a single 600mg oral dose of alectinib in the first period, and a single 600mg/67Ci oral dose of radiolabelled alectinib was administered in the second period to six healthy male subjects. 3.The absolute bioavailability of alectinib was moderate at 36.9%. Geometric mean clearance was 34.5L/h, volume of distribution was 475L and the hepatic extraction ratio was low (0.14). 4.Near-complete recovery of administered radioactivity was achieved within 168h post-dose (98.2%) with excretion predominantly in faeces (97.8%) and negligible excretion in urine (0.456%). Alectinib and its major active metabolite, M4, were the main components in plasma, accounting for 76% of total plasma radioactivity. In faeces, 84% of dose was excreted as unchanged alectinib with metabolites M4, M1a/b and M6 contributing to 5.8%, 7.2% and 0.2% of dose, respectively. 5.This novel study design characterised the full absorption, distribution, metabolism and excretion properties in each subject, providing insight into alectinib absorption and disposition in humans.