UC San Diego

Study objectives

Solriamfetol, a dopamine/norepinephrine reuptake inhibitor, is approved in the United States and European Union to treat excessive daytime sleepiness in patients with obstructive sleep apnea (OSA) (37.5-150 mg/day) and narcolepsy (75-150 mg/day). This analysis evaluated solriamfetol's efficacy in subgroups of participants with OSA who were adherent or nonadherent to primary OSA therapy at baseline and examined whether solriamfetol affected the use of primary therapy in an open-label extension trial.

Methods

Participants with OSA who completed prior solriamfetol studies received solriamfetol 75, 150, or 300 mg/day for ≤ 52 weeks. The main efficacy outcome was the Epworth Sleepiness Scale score. Primary therapy use was summarized as the percentage of nights, the number of hours/night, and the percentage of nights with use ≥ 50%/night (%). Efficacy and primary therapy use are reported for participants who directly enrolled from a previous 12-week study and had ≤ 40 weeks of open-label treatment (n = 333). Safety data are reported for all participants (n = 417).

Results

Mean ESS scores in adherent (n = 255) and nonadherent (n = 78) subgroups, respectively, were 15.0 and 15.8 at baseline (of 12-week study) and 6.5 and 6.8 at week 40. For participants using an airway therapy, mean use at baseline was 90% of nights, 6.6 hours/night, and use ≥ 50%/night on 90% of nights; changes from baseline to week 40 were minimal (0.9%, -0.8 hours, and 6.5%, respectively). Common adverse events (both subgroups) included headache, nasopharyngitis, insomnia, dry mouth, nausea, anxiety, and upper respiratory tract infection.

Conclusions

Long-term efficacy and safety of solriamfetol were similar regardless of adherence to primary OSA therapy. Solriamfetol did not affect primary therapy use.

Clinical trial registration

Registry: ClinicalTrials.gov; Name: A Long-Term Safety Study of JZP-110 in the Treatment of Excessive Sleepiness in Subjects with Narcolepsy or OSA; URL: https://clinicaltrials.gov/ct2/show/NCT02348632; Identifier: NCT02348632 and Registry: EU Clinical Trials Register; Identifier: 2014-005489-31; URL: https://www.clinicaltrialsregister.eu/ctr-search/search?query=2014-005489-31..