KEY-507-A

KEY-507-A is an investigational lower-sodium oxybate oral solution formulation developed by Jazz Pharmaceuticals. It was evaluated alongside three other formulations (KEY-507-G, KEY-507-C, and KEY-507-D) under the broader JZP-507 development program. In an open-label, randomized crossover first-in-human pilot study in healthy adult volunteers, these formulations were compared to Xyrem (sodium oxybate) to assess pharmacokinetics, relative bioavailability, bioequivalence, safety, tolerability, and taste under fasting conditions. KEY-507-A is a formulation of oxybate (gamma-hydroxybutyrate/GHB) designed with reduced sodium content relative to Xyrem, targeting GABA-B receptors for the treatment of narcolepsy symptoms, such as cataplexy and excessive daytime sleepiness. While JZP-507 formulations demonstrated bioequivalence to Xyrem, Jazz Pharmaceuticals ultimately decided to prioritize LXB (which became Xywav), a formulation with a 92% reduction in sodium content compared to JZP-507's 50% reduction, meaning KEY-507-A did not advance independently to approval.