Solriamfetol May Improve Sleep Latency Among Patients With Parkinson Disease

This phase 2, double-blind trial of solriamfetol evaluated the dose-dependent effects on sleep latency in patients with Parkinson disease.

A phase 2 double-blind trial of solriamfetol for excessive daytime sleepiness (EDS) among patients with Parkinson disease (PD) found a dose-dependent improvement in sleep latency. These findings were published in Movement Disorders.

Patients (N=66) with PD and EDS were recruited from 33 sites in the United States between 2017 and 2018. Randomization occurred in a 3:3:1 ratio to receive treatment with sequence A, B, or C. Treatments comprised 4 1-week periods of placebo, 75, 150, 300 mg solriamfetol (A); 75, 150, 300 mg solriamfetol, placebo (B); or 4 weeks of placebo (C). Participants were assessed for safety, tolerability, and efficacy. This trial was conducted by Jazz Pharmaceuticals.

Treatment-emergent adverse events were reported by 58.9%. Frequent events included nausea (10.7%), dizziness (7.1%), dry mouth (7.1%), headache (7.1%), anxiety (5.4%), constipation (5.4%), and dyspepsia (5.4%). A single patient had a serious adverse event during the 300 mg dose phase and 3 discontinued use due to a non-serious adverse event.

According to the Epworth Sleepiness Scale (ESS), the least-squares mean change from baseline was -0.03 (P =.9546) for the 75 mg dose, -0.25 (P =.7104) for the 150 mg dose, and -0.93 (P =.1276) for the 300 mg dose.

Maintenance of Wakefulness Test (MWT) mean sleep latency had a dose-dependent improvement of 5.05 (95% CI, 1.24-8.57; P =.0098) minutes for the 300 mg dose compared with placebo.

No significant effect on PD motor or nonmotor symptoms were observed.

This study was underpowered and statistical tests could not be performed among subgroups. In addition, the MWT instrument has not been validated for use among the PD population.

This phase 2 trial did not identify any new adverse events of safety concerns associated with solriamfetol therapy. No evidence of worsening PD symptoms were reported. Solriamfetol may improve sleep latency among patients with PD, but there was limited evidence to suggest EDS was improved.

Disclosure: Multiple authors declared affiliations with the pharmaceutical industry. Please refer to the original article for a full list of disclosures.


Videnovic A, Amara AW, Comella C, et al. Solriamfetol for Excessive Daytime Sleepiness in Parkinson’s Disease: Phase 2 Proof-of-Concept Trial. Mov Disord. Published online June 30, 2021. doi:10.1002/mds.28702