Jazz Pharmaceuticals plc and Concert Pharmaceuticals Inc have completed Phase 1 clinical study of JZP-386, a deuterium-containing analog of sodium oxybate. The Phase 1 study evaluated the safety, pharmacokinetics, and pharmacodynamics (PD) of JZP-386 in 30 healthy volunteers.

Clinical data from this Phase 1 study demonstrated that JZP-386 provided favorable deuterium-related effects, including higher serum concentrations and correspondingly increased PD effects at clinically relevant time points compared to Xyrem (sodium oxybate) oral solution. The safety profile of JZP-386 was similar to that observed with Xyrem. While the companies have determined that the deuterium-related effects observed in the Phase 1 studies do not support advancing into a later-stage clinical trial of JZP-386 at this time, the results indicate that further evaluation of JZP-386 is warranted. Accordingly, the companies intend to explore formulation options to enhance the positive effects observed in the studies to achieve an improved product profile for patients with narcolepsy.

Sodium oxybate is the active ingredient in Xyrem, a prescription medicine marketed in the United States by Jazz Pharmaceuticals to treat cataplexy and excessive daytime sleepiness in patients with narcolepsy.