ML350 , also known as CYM-50202, is an antagonist of KOR (IC50 = 12.6 nM) with good and moderate selectivity against the DOR and MOR. CYM-50202 displayed high solubility, an encouraging pharmacokinetic (PK) profile in rat, and excellent CNS penetration. Perhaps more importantly, CYM-50202_x000D_
did not display long lasting pharmacodynamic effects observed with prototypical KOR antagonists.