Preclinical metabolism and disposition of [14C]GFH009, a novel selective CDK9 inhibitor.

GFH009 is a potent and highly selective cyclin-dependent kinase 9 (CDK9) inhibitor currently under phase II clinical trials. In this study, we investigated the metabolism and disposition of GFH009 in Sprague-Dawley (SD) rats, as well as in vitro metabolism of CD-1 mouse, SD rat, beagle dog, cynomolgus monkey, and human.A radiolabelled study indicated that [14C]GFH009 was quickly and widely distributed throughout the body, but presented low levels in brain, testis, and epididymis after a single intravenous dose of 6 mg (100 µCi)/kg to SD rats.GFH009 undergoes systemic metabolic changes, primarily through O-demethylation, oxidation to carboxylic acid and N-dealkylation, cleavage off the methoxyisopropyl moiety being a minor pathway. These metabolic pathways were found to be mainly consistent both in vitro and in vivo.In SD rats, GFH009 was rapidly and completely eliminated, with faeces serving as the major excretion pathway and urine serving as the minor one. Besides, the major clearance pathway for GFH009 was excretion and the minor one was metabolism.GFH009 exhibits favourable drug metabolism and pharmacokinetics (DMPK) properties, which provides valuable insights into the disposition of GFH009 and can be used to guide future clinical studies.