Studies of pharmacokinetics in beagle dogs and drug-drug interaction potential of a novel selective ZAK inhibitor 3h for hypertrophic cardiomyopathy treatment.

Overexpression of leucine-zipper and sterile-α motif kinase (ZAK) in heart has been closely associated with the development of hypertrophic cardiomyopathy (HCM). N-(3-(1H-pyrazolo[3,4-b]pyridin-5-yl)ethynyl) benzene-sulfonamides, novel highly selective ZAK inhibitors, had exhibited reasonable orally therapeutic effects on HCM in spontaneous hypertensive rat models. In the present study, a rapid and sensitive HPLC-MS/MS method for determining ZAK inhibitor 3h in beagle dog plasma was developed and validated. Meanwhile, the pharmacokinetics in beagle dog and drug-drug interaction potential of 3h had been conducted. The pharmacokinetic results showed that the absolute oral bioavailability for 3h in beagle dogs was determined to be 61.9%, which was significantly higher than that in the previous determination in Spragur-Dawley rats (F = 20%). The Cytochrome P450 enzymes and P-glycoprotein mediated drug-drug interactions by 3h were also investigated using dog and human liver microsomes and Caco-2 cells. The results demonstrated that only CYP2C9 was obviously inhibited (IC50 = 1.66 µM). Besides, 3h could significantly decrease digoxin efflux ratio in Caco-2 experiments in a dose-dependent manner (IC50 = 13.3 µM). Considering 3h strongly suppressed the ZAK kinase activity with an IC50 of 3.3 nM, there are significantly differences between this IC50 value for ZAK inhibition and the present determinations of IC50 values. In general, the clinical drug-drug interaction potential for 3h could be well monitored during the treatment of HCM.