Solriamfetol Titration & AdministRaTion (START) in Patients With Narcolepsy

Abstract

PurposeSolriamfetol, a dopamine/norepinephrine reuptake inhibitor, is approved (in the United States and European Union) to treat excessive daytime sleepiness (EDS) in adults with narcolepsy (75–150 mg/d) or obstructive sleep apnea (OSA) (37.5–150 mg/d). This study characterized real-world titration strategies for patients with narcolepsy (with or without comorbid OSA) initiating solriamfetol therapy. MethodsThis virtual, descriptive study included a retrospective medical record review and qualitative survey. US-based physicians prescribing solriamfetol for EDS associated with narcolepsy or OSA participated. Data are reported for patients with narcolepsy with or without comorbid OSA (OSA alone reported separately). On the basis of medical record review, titration strategies were classified de novo (EDS medication naive), transition (switched or switching from existing EDS medication[s] to solriamfetol), or add-on (adding solriamfetol to current EDS medication[s]). The survey included open-ended questions regarding a hypothetical patient—a 32-year-old woman with narcolepsy (Epworth Sleepiness Scale score of 8) treated with 35 mg/d of amphetamine and 6 g per night of sodium oxybate who experiences non–use-limiting adverse events from amphetamine. FindingsTwenty-six physicians participated: 23 provided data from 70 patients with narcolepsy (type 1, n = 24; type 2, n = 46; mean [SD] age, 40 [11] years; 57% female; 6 with comorbid OSA), and 26 responded to the hypothetical patient scenario. From the medical record review, solriamfetol therapy initiation was de novo for 19 of 70 patients (27%), transition for 31 of 70 patients (44%), and add-on for 20 of 70 patients (29%). Efficacy profile of solriamfetol was the primary reason for de novo (12 of 19 [63%]), transition (18 of 31 [58%]), and add-on (19 of 20 [95%]) initiation. Most (86%) initiated use of solriamfetol at 75 mg/d and were stable at 150 mg/d (76%). Most (67%) had 1 dose adjustment, reaching a stable dose over a median (range) of 14 (1–60) days. Physicians most often considered EDS severity (44%) when titrating. Among transitioning patients, 14 of 22 (64%) using wake-promoting agents discontinued their use abruptly, and 5 of 9 (56%) using stimulants were tapered off. At data collection, 90% continued to take solriamfetol. Regarding the hypothetical patient scenario, most physicians (81%) thought solriamfetol was appropriate, highlighting tolerability issues with current treatment and lack of symptom control as drivers for switching; however, 3 physicians (12%) did not think solriamfetol was appropriate, noting current symptoms were not severe enough and/or symptoms could be managed by increasing sodium oxybate dose; 2 (8%) thought it would depend on other factors. Physicians emphasized managing withdrawal symptoms while maintaining EDS symptom control when titrating off a stimulant and starting solriamfetol therapy. ImplicationsIn a real-world study, physicians initiated solriamfetol therapy at 75 mg/d for most patients with narcolepsy, adjusted dosages once, tapered stimulants, and abruptly discontinued therapy with wake-promoting agents.