Structure–activity relationships, and drug metabolism and pharmacokinetic properties for indazole piperazine and indazole piperidine inhibitors of ROCK-II

ROCK has been implicated in many diseases ranging from glaucoma to spinal cord injury and is therefore an important target for therapeutic intervention. In this study, we have designed a series of 1-(4-(1H-indazol-5-yl)piperazin-1-yl)-2-hydroxy(or 2-amino) analogs and a series of 1-(4-(1H-indazol-5-yl amino)piperidin-1-yl)-2-hydroxy(or 2-amino) inhibitors of ROCK-II. SR-1459 has IC50 = 13 nM versus ROCK-II while the IC50s for SR-715 and SR-899 are 80 nM and 100 nM, respectively. Many of these inhibitors, especially the 2-amino substituted analogs for both series, are modest/potent CYP3A4 inhibitors as well. However, a few of these inhibitors (SR-715 and SR-899) show strong selectivity for ROCK-II over CYP3A4, but the overall potency of the 2-amino analogs (SR-1459) on CYP3A4 and the high clearance and volume of distribution of these compounds makes the in vivo utility of these analogs undesirable.