Improving the Pharmacokinetic and CYP Inhibition Profiles of Azaxanthene-Based Glucocorticoid Receptor ModulatorsIdentification of (<i>S</i>)‑5-(2-(9-Fluoro-2-(4-(2-hydroxypropan-2-yl)phenyl)‑5<i>H</i>‑chromeno[2,3‑<i>b</i>]pyridin-5-yl)-2-methylpropanamido)‑<i>N</i>‑(tetrahydro‑2<i>H</i>‑pyran-4-yl)-1,3,4-thiadiazole-2-carboxamide (BMS-341)

An empirical approach to improve the microsomal stability and CYP inhibition profile of lead compounds <b>1a</b> and <b>1b</b> led to the identification of <b>5</b> (BMS-341) as a dissociated glucocorticoid receptor modulator. Compound <b>5</b> showed significant improvements in pharmacokinetic properties and, unlike compounds <b>1a</b>–<b>b</b>, displayed a linear, dose-dependent pharmacokinetic profile in rats. When tested in a chronic model of adjuvant-induced arthritis in rat, the ED₅₀ of <b>5</b> (0.9 mg/kg) was superior to that of both <b>1a</b> and <b>1b</b> (8 and 17 mg/kg, respectively)