KEY-507-C

KEY-507-C is an investigational, lower-sodium oxybate oral solution formulation developed by Jazz Pharmaceuticals for the treatment of narcolepsy, specifically targeting symptoms such as cataplexy and excessive daytime sleepiness (EDS). It was evaluated as one of four pilot formulations (alongside KEY-507-A, KEY-507-G, and KEY-507-D) in an open-label, randomized crossover first-in-human study in healthy volunteers to assess its pharmacokinetics, relative bioavailability, bioequivalence, safety, tolerability, and taste compared to Xyrem (sodium oxybate). As a lower-sodium formulation, KEY-507-C contains the active moiety oxybate (the salt of gamma-hydroxybutyrate, GHB) but with a reduced sodium content, designed to mitigate the cardiovascular risks associated with the high sodium intake of standard sodium oxybate. Its therapeutic effects are mediated primarily through the activation of GABA-B receptors. Development of this specific formulation was not pursued further, as Jazz Pharmaceuticals ultimately advanced other lower-sodium formulations (such as JZP-258/Xywav).