Solriamfetol for Excessive Daytime Sleepiness in Parkinson's Disease: Phase 2 Proof‐of‐Concept Trial

BACKGROUND: Solriamfetol is approved (US and EU) for excessive daytime sleepiness (EDS) in narcolepsy and obstructive sleep apnea.

OBJECTIVES: Evaluate solriamfetol safety/efficacy for EDS in Parkinson's disease (PD).

METHODS: Phase 2, double‐blind, 4‐week, crossover trial: adults with PD and EDS were randomized to sequence A (placebo, solriamfetol 75, 150, 300 mg/d), B (solriamfetol 75, 150, 300 mg/d, placebo), or C (placebo).

Outcomes (safety/tolerability [primary]; Epworth Sleepiness Scale [ESS]; Maintenance of Wakefulness Test [MWT]) were assessed weekly.

P values are nominal.

RESULTS: Common adverse events (n = 66): nausea (10.7%), dizziness (7.1%), dry mouth (7.1%), headache (7.1%), anxiety (5.4%), constipation (5.4%), dyspepsia (5.4%).

ESS decreased both placebo (−4.78) and solriamfetol (−4.82 to −5.72; P > 0.05).

MWT improved dose‐dependently with solriamfetol, increasing by 5.05 minutes with 300 mg relative to placebo (P = 0.0098).

CONCLUSIONS: Safety/tolerability was consistent with solriamfetol's known profile.

There were no significant improvements on ESS; MWT results suggest possible benefit with solriamfetol in PD.

© 2021 The Authors.

Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society