Titration Common in Solriamfetol, Leads to Improvements in Daytime Sleepiness

Yaroslav Winter, MD, MSc

Solriamfetol (Sunosi; Axsome Therapeutics), an FDA-approved medication for excessive daytime sleepiness (EDS), is typically initiated at 75 mg/day, with titration common, according to the SURWEY study assessing real-world physician strategies. Following initiation, patients experienced improvements in Epworth Sleepiness Scale (ESS) scores, and most patients perceived improvement in their EDS status.

The most common starting doses overall were 75 mg/day (69%) or 150 mg/day (20%), with most of the remaining patients initiated at 37.5 mg. Almost half (43%) of patients had their treatment titrated, with 90% completing titration as prescribed. Titration was most commonly completed within 7 days (57%). For patients who changed treatment, switching to solriamfetol was managed using an abrupt approach for 88% of patients, an overlapping (tapered) approach for 9% of patients, and an unknown approach for 2% of patients.

Retrospective chart reviews from 70 German adults with EDS and narcolepsy were collected by investigators, with patients classified as either changeover (n = 43; 61%), add-on (n = 19; 27%), or new-to-therapy (n = 8; 11%) subgroups, based on existing EDS treatment. The mean age of the cohort was 36.9 (±13.9) years and mean body mass index was 26.7 (standard deviation [SD]. 5.2) kg/m. More than half (57%) had cataplexy, and most (84%) were treated in sleep centers.

The SURWEY study, led by Yaroslav Winter, MD, MSc, head of Mainz Comprehensive Epilepsy and Sleep Medicine Center, Johannes Gutenberg University, was initiated to collect data describing real-world physician dosing and titration strategies, which may help health providers optimize care for European patients. Solriamfetol, a dopamine/norepinephrine reuptake inhibitor, was approved in the European Union in 2020 and the United States in 2019 to treat EDS associated with narcolepsy (75-150 mg/day) and obstructive sleep apnea (OSA; 37.5-150 mg/day).

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SURWEY began in November 2020 and was expected to be open for around 24 months. Eligible patient had achieved a stable dose of solriamfetol and completed at least 6 weeks of treatment. Prior to solriamfetol, the most commonly reported previous medications were modafinil (66%), which was reported for 74%, 63%, 25%, of the changeover, add-on, and new-to-therapy subgroups, respectively, followed by pitolisant (49%). At the time solriamfetol treatment was initiated, patients in the changeover and add-on subgroups were taking sodium oxybate (23% and 37%, respectively), pitolisant (9% and 42%, respectively), modafinil (16% and 11%), methylphenidate (2% and 11%, respectively), amphetamine/stimulants (9% and 0%, respectively), and other medications (23% and 26%, respectively).

From initiation to follow-up, there the mean ESS score improved from 17.6 to 13.6. ESS scores improved regardless of initiation strategy, with mean decreases of 4.1 (SD, 2.9), 3.7 (SD, 2.6), and 6.1 (SD, 3.0) points from solriamfetol initiation to follow-up in the changeover, add-on, and new-to-therapy subgroups, respectively. Overall, 91% of patients reported slight or strong improvements in their EDS after initiating solriamfetol, with results similar across subgroups. From physician perspective, most patients (94%) had slight or strong improvements in EDS.

At the conclusion of the study, 72% of the cohort reported no change in their perceived nighttime sleep quality after solriamfetol initiation; however, some patients (19%) reported improvements. Specifically, 23%, 12%, and 13%, of those in the changeover, add-on, and new-to-therapy subgroups, respectively, noted improvements. Throughout the study, 30% of the cohort experienced adverse events, the most common were headache (9%), decreased appetite (6%), and insomnia (6%).

REFERENCE
1. Winter Y, Mayer G, Kotterba S. Solriamfetol real world experience study (SURWEY): initiation, titration, safety, effectiveness, and experience during follow-up for patients with narcolepsy from Germany. Sleep Med. 2023;103:138-143. doi:10.1016/j.sleep.2023.01.022.