Solriamfetol Efficacious, Easily Titrated in Patients Initiating Treatment for Narcolepsy

Results from the START study of medication switching in narcolepsy were presented at the 2021 SLEEP Annual Meeting.

Data from the solriamfetol titration & administration (START) study presented at the 2021 SLEEP Virtual Annual Meeting, June 10-13, suggest that solriamfetol (Sunosi; Jazz Pharmaceuticals) is efficacious in patients switching narcolepsy medications and is easily titrated for these individuals.1

“Pharmacotherapy for excessive daytime sleepiness (EDS) associated with narcolepsy is diverse, with factors such as efficacy, side effects, and tolerance influencing treatment decisions,” first author Michael J. Thorpy, MD, director, Sleep-Wake Disorders Center, Montefiore and professor of neurology, Albert Einstein College of Medicine, and colleagues wrote.2 Solriamfetol, a dopamine/norepinephrine reuptake inhibitor, is approved to treat EDS in adults with narcolepsy or obstructive sleep apnea (OSA) in the US and EU.

The START study consisted of a quantitative retrospective patient chart review among US-based physicians prescribing solriamfetol de novo, in transition from, or in addition to existing medications. Altogether, 26 physicians with 70 patients with narcolepsy participated. Most patients had narcolepsy type 2 (NT2; n = 46) while 24 had type 1 (NT1). Patients had a mean age of 40 years (standard deviation [SD], 11), 57% were women, and 6 also had OSA. Most cases of EDS were moderate (59%) or severe (36%). Comorbidities included obesity (n = 22; 31%), migraine headaches (n = 12; 17%), depression (n = 10; 14%), and cardiovascular disorders (n = 10; 14%).

The first presentation from the meeting investigated characteristics of real-world patients with narcolepsy starting solriamfetol and prescribers’ rationales for initiating treatment in a virtual, descriptive study. Solriamfetol initiation was mostly transition (n = 31; 44%) followed by add-on (n = 20; 29%), and de novo (n = 19; 27%).

READ MORE: Solriamfetol and the Impact of Residual Excessive Daytime Sleepiness

Patients transitioning to solriamfetol were taking 1 (n = 29; 94%) or 2 (n = 2; 7%) prior EDS medications. Patients adding solriamfetol were taking 1 (n = 16; 80%), 2 (n = 3; 15%) or 3 (n = 1; 5%). Most patients transitioning were taking wake-promoting agents (n = 22; 71%) and patients adding were most frequently taking sodium oxybate (n = 11; 55%). 

Solriamfetol’s efficacy profile was the primary reason for prescription de novo (n = 12; 63%), while need for better efficacy/augmenting effects of other medications was the primary reason for transitioning (n = 18; 58%) and add-on therapy (n = 19; 95%). At the time of data collection, 63 (90%) patients were on a stable solriamfetol dose. A small number of discontinuations occurred due to lack of efficacy (n = 3) and adverse events (n = 3).

The next study presented characterized real-world dosing and titration of solriamfetol. Most patients (86%) started solriamfetol at 75 mg; 11% started at 37.5 mg and 3% started at 150 mg. The final dose was 150 mg for 53 (76%) patients and 75 mg for 17 (24%). Most patients (67%) had 1 dose adjustment to reach their final dose; 4% had 2 adjustments, 4% had 3 adjustments, and 24% had none. Mean time to reach a stable dose was 15.1 days (SD, 11.8) overall, 19.4 days (SD, 9.3) with de novo treatment, 15.0 days (SD, 13.7) for transition, and 11.9 days (SD, 8.6) for add-on.3 

Physicians most frequently considered EDS severity (44%) when titrating. Fourteen of 22 transitioning patients (64%) taking a wake-promoting agent (WPA) discontinued it abruptly and 5 of 9 (56%) taking a stimulant were tapered off. Physicians were overall likely (n = 33; 47%) or very likely (n = 30; 43%) to recommend their approach for similar patients. 

"Jazz continues to be committed to deepening our understanding of sleep disorders and delivering transformational medicines to those with lifelong and chronic sleep conditions," said Robert Iannone, MD, MSCE, executive vice president, research and development and chief medical officer, Jazz Pharmaceuticals, in a statement.1 "There remains a large unmet need for people living with sleep disorders, including narcolepsy and idiopathic hypersomnia, and we look forward to showcasing the latest research and results from our portfolio during SLEEP 2021 as we work to help people with sleep disorders live fuller lives."

1. Jazz Pharmaceuticals Presents 18 Abstracts in Sleep Medicine at SLEEP 2021. News release. Jaz Pharmaceuticals. June 9, 2021.
2. Thorpy M, Hyman D, Parks G, et al. Solriamfetol titration & administration (START): Characteristics of patients with narcolepsy and solriamfetol prescriber rationale. Presented at SLEEP 2021; June 10-13. Abstract 481.
3. Thorpy M, Hyman D, Parks G, et al. Solriamfetol titration & administration (START): Dosing and titration strategies in patients with narcolepsy starting solriamfetol. Presented at SLEEP 2021; June 10-13. Abstract 482.