Abstract
STUDY OBJECTIVES: To evaluate the clinical relevance of solriamfetol in treating excessive daytime sleepiness in participants with narcolepsy or obstructive sleep apnea (OSA). METHODS: This posthoc analysis includes data from two 12-week, randomized phase 3 studies in participants with narcolepsy or OSA treated with once-daily placebo or solriamfetol 37.5 mg (OSA only), 75 mg, 150 mg, or 300 mg. Excessive daytime sleepiness was assessed with the Epworth Sleepiness Scale (ESS) at baseline and at week 12. Cumulative distribution function plots were generated using a last-observation-carried-forward approach to determine the percentage of participants who achieved ESS scores ≤ 10, within the normal range, and the percentage who achieved a reduction (improvement) in ESS ≥ 25% relative to baseline. Safety was also assessed. RESULTS: In narcolepsy (n = 231), 30.5%-49.2% of participants treated with solriamfetol (across doses) reported ESS scores ≤ 10 and 44.1%-62.7% achieved a ≥ 25% decrease from baseline in ESS scores at week 12, compared with 15.5% and 27.6%, respectively, of placebo recipients. In OSA (n = 459), 51.8%-73.0% of participants treated with solriamfetol (across doses) reported ESS scores ≤ 10 and 50.0%-81.9% achieved a ≥ 25% decrease from baseline in ESS scores at week 12, compared with 37.7% and 36.8%, respectively, of placebo recipients. Results were generally dose-dependent, with more responders at higher solriamfetol doses. Common treatment-emergent adverse events (≥ 5% of solriamfetol recipients in either study) were headache, nausea, decreased appetite, nasopharyngitis, dry mouth, and anxiety. CONCLUSIONS: A greater percentage of participants treated with solriamfetol achieved normal ESS scores (≤ 10) or clinically meaningful improvements on the ESS compared with those receiving placebo. The safety profile was similar between participants with narcolepsy and those with OSA. CLINICAL TRIAL REGISTRATIONS: Registry: ClinicalTrials.gov. Names: TONES 2 and TONES 3. URLs: https://www.clinicaltrials.gov/ct2/show/NCT02348593 and https://www.clinicaltrials.gov/ct2/show/NCT02348606. Identifiers: NCT02348593, NCT02348606. Registry: European Union Drug Regulating Authorities Clinical Trials. Names: TONES 2 and TONES 3. URL: https://www.eudract.ema.europa.eu. Identifiers: EudraCT 2014-005487-15, EudraCT 2014-005514-31.