0393 Weight Changes During Treatment With Lower-Sodium Oxybate in a Phase 3 Clinical Study in Patients With Narcolepsy

Abstract Introduction Treatment with sodium oxybate (SXB) has been associated weight loss in patients narcolepsy. Lower-sodium (LXB) contains the same active moiety as SXB, 92% less sodium, and is approved US for treatment of cataplexy or excessive daytime sleepiness ≥7 years age narcolepsy adults idiopathic hypersomnia. This analysis assessed changes after 14 weeks open-label LXB a phase 3 clinical study (NCT03030599). Methods Participants 18‒70 (taking SXB only, SXB+other anticataplectics, other who were anticataplectic-naive at entry) began 12-week, open-label, optimized titration period, followed by 2-week stable-dose period (SDP) on LXB. Results Study participants (N=201) had mean (SD) 37.2 (12.2) years. At baseline, body mass index (BMI) 83.7 (19.2) kg 28.8 (6.1) kg/m2, respectively; 31.8% (64/201) normal (BMI 18.5 to <25 kg/m2), overweight 25 <30 35.3% (71/201) obese ≥30 kg/m2). end SDP, BMI SXB-only (n=45 weight; n=44 BMI), SXB+anticataplectics (n=14), other-anticataplectics (n=23), (n=65) were, respectively, −0.2 (2.5) 0.0 (0.9) −1.0 (1.9) −0.3 (0.6) −2.3 (4.0) −0.8 (1.4) −2.5 (3.8) −0.9 (1.3) kg/m2. Weight ≥5% SDP occurred 6.7% SXB-only, 0.0% SXB+anticataplectics, 21.7% other-anticataplectics, 27.7% participants. In weight, overweight, decreases −1.5 (3.1) kg, −3.3 (3.5) −2.6 (4.7) respectively (participants oxybate-naive entry), −0.1 (1.8) (2.4) 0.2 (2.8) taking entry). Conclusion this study, entry experienced greater during compared previously SXB. Support (If Any) Jazz Pharmaceuticals.