Jazz Pharmaceuticals plc announced the Health Canada approval and availability of Sunosi (solriamfetol) for the treatment of excessive daytime sleepiness (EDS) associated with narcolepsy or obstructive sleep apnea (OSA) in adult patients. Once-daily Sunosi is approved with doses of 75 mg and 150 mg. Sunosi is the first dopamine and norepinephrine reuptake inhibitor (DNRI) approved to treat EDS in adults living with narcolepsy or OSA. EDS is characterized by the inability to stay awake and alert during the day resulting in unplanned lapses into sleep or drowsiness. Major contributors to EDS are narcolepsy, a chronic, debilitating neurological disorder characterized by the inability to regulate sleep-wake cycles normally and OSA, a condition where a person's breathing stops for brief periods of time when they sleep. The approval of Sunosi is based on data from the Treatment of Obstructive Sleep Apnea and Narcolepsy Excessive Sleepiness (TONES) Phase 3 clinical program which enrolled over 1,500 adults in four randomized placebo-controlled studies. Data from the studies in the TONES program demonstrated the superiority of solriamfetol relative to placebo. The efficacy of Sunosi in reducing EDS in patients with narcolepsy or OSA was assessed in the pivotal studies, two randomized, 12-week, placebo-controlled studies, Study 14-002 (TONES 2, narcolepsy patients) and Study 14-003 (TONES 3, OSA patients). At Week 12 of these trials, 150 mg of solriamfetol for narcolepsy patients and both 75 mg and 150 mg doses for OSA patients demonstrated significant improvements in wakefulness and reduced sleepiness compared to placebo as assessed via the Maintenance of Wakefulness Test (MWT) and Epworth Sleepiness Scale respectively (ESS). Furthermore, the increase in the MWT sleep latency was maintained through nine-hours from morning dosing. Up to 78% of the narcolepsy patients and up to 90% of the OSA patients taking 150 mg reported feeling better as measured by the Patient Global Impression of Change (PGIc) scale. The efficacy of Sunosi was shown be maintained for at least 6 months in a long-term open label follow up study (TONES 5). In TONES 2 and 3, the most common treatment emergent adverse events reported in patients treated with Sunosi (incidence =5% and greater than placebo) in either the narcolepsy or OSA populations were headache, nausea, decreased appetite, anxiety and insomnia.