Abstract Introduction Sodium oxybate is strongly recommended by the American Academy of Sleep Medicine for the treatment of narcolepsy, a chronic sleep disorder characterized by excessive daytime sleepiness (EDS). This study was conducted to characterize demographic characteristics and concomitant medication use of patients with narcolepsy treated or not treated with oxybates (OXB). Methods An electronic health record–based search identified first-time patients from Mayo Clinic and Duke Health between 2002-2024 and 2012-2024, respectively. Patients had ≥1 narcolepsy-specific ICD-9/10 code and ≥1 diagnostic mention of narcolepsy in clinical notes (via natural language processing algorithm). Patients from both Mayo Clinic and Duke Health who were or were not treated with OXB were identified. Data were analyzed descriptively. Results Of 4722 patients, 654 (Mayo Clinic, n=378; Duke Health, n=276) received OXB, and 4068 (Mayo Clinic, n=2800; Duke Health, n=1268) received non-OXB treatments. The majority of patients were white (OXB-treated: 92.1%, 73.6%; non–OXB-treated: 91.1%, 69.2%) and female (OXB-treated: 68.3%, 76.8%; non–OXB-treated: 61.7%, 68.1%). Most OXB-treated patients (65.3%; 63.4%) had narcolepsy type 1 (NT1); the majority of non–OXB-treated patients (78.1%; 64.0%) had narcolepsy type 2 (NT2). The mean (SD) age of the OXB-treated cohort was younger than the non–OXB-treated cohort at the time of diagnosis (OXB-treated: 33.9 [15.3] years, 35.7 [13.2] years; non–OXB-treated: 45.5 [19.2] years, 42.5 [17.8] years). For both cohorts, the most common concomitant medications were stimulants (OXB-treated: 50.3%, 42.8%; non–OXB-treated: 41.8%, 35.2%). Conclusion In this retrospective analysis of nearly 5000 patients from Mayo Clinic and Duke Health, approximately 1 in 8 received OXB. While sodium oxybate has been approved for >2 decades and is strongly recommended for treatment of both EDS and cataplexy in narcolepsy, substantially greater OXB utilization was observed in patients with NT1. As both patients with NT1 and NT2 can experience other narcolepsy symptoms, further OXB-related education remains critical—particularly on the efficacy of sodium oxybate in the treatment of NT2. Support (if any) Avadel Pharmaceuticals
1246 Examining Unaddressed Needs in Narcolepsy Type 1 Care to Inform Clinical Practice Improvements
Abstract Introduction As targeted treatments for narcolepsy type 1 (NT1) emerge, timely diagnosis and care planning are essential to optimize outcomes. This ongoing initiative aims to identify and address barriers to NT1 recognition and treatment to support practice improvements and patient-centered care. Methods Patient surveys (N=38) were collected in August 2025 through collaboration with the Hypersomnia Foundation to inform an ongoing initiative at five US sleep centers. Results from patient surveys are reviewed at expert-led clinic-based sessions to identify patient needs in care, and case-based discussions challenge participants to apply the latest evidence into practice scenarios. Pre- and post-session surveys are designed to measure the impact on knowledge, confidence, and self-reported performance. Additionally, clinicians will develop strategies for care improvement. Results The top patient-reported barriers to NT1 diagnosis were finding a provider familiar with sleep disorders (42%) and limited appointments/referrals (26%). Ninety-five percent waited over 1 year for formal diagnosis (1-5 years, 71%; 5-10 years, 19%; >10 years, 5%). Narcolepsy symptoms had a significant impact on daily living (82%; 4 or 5 on a 5-point Likert scale), with many patients reporting fatigue (63%), excessive daytime sleepiness (58%), disrupted nighttime sleep (53%), sleep paralysis (50%), and cataplexy (37%) despite treatment. Patients’ top treatment goals were finding a treatment that is effective for their symptoms/type of narcolepsy (61%) and that improves daily functioning/quality of life (55%). However, 19% (1, 2, or 3 on a 5-point Likert scale) reported their care team had not discussed treatment options and 37% (1, 2, or 3 on a 5-point Likert scale) were not routinely asked about treatment goals. Patients were interested in discussing the cause of narcolepsy (63%) and their preferences for treatment (61%). Preliminary findings from the clinic-based sessions have generated practical strategies to address identified gaps in NT1 care. Conclusion Patient surveys uncovered persistent challenges in NT1 diagnosis, communication, and treatment planning. Incorporating these perspectives and case-based scenarios into clinic-based sessions have the potential to improve focused approaches to care and can provide a foundation for integrating evidence into practice as the NT1 landscape evolves. Support (if any) This program was supported by an educational grant from Takeda Pharmaceuticals U.S.A., Inc.
0731 Cognitive and Functional Outcomes from the Phase 3 Open-Label Extension and Randomized-Withdrawal ENCORE Trial of AXS-12 in Narcolepsy with Cataplexy
Abstract Introduction AXS-12 (reboxetine) is a highly selective norepinephrine reuptake inhibitor and cortical dopamine modulator under development for the treatment of narcolepsy. Long-term efficacy and safety of AXS-12 in participants with narcolepsy with cataplexy (NT1) were previously reported from the Phase 3 ENCORE trial. To better understand the impact of AXS-12 on overall functional burden in NT1, we evaluated changes in cognition and functional outcomes during the ENCORE trial. Methods ENCORE included a 24-week open-label extension (OLE) period, followed by a 3-week double-blind randomized-withdrawal (DBRW) period. During the OLE, participants received AXS-12 (5 mg once-daily for 1 week, twice-daily for 23 weeks). Following this, participants were randomized 1:1 to continue twice-daily AXS-12 for 3 weeks or switch to once-daily AXS-12 plus placebo for 1 week, then placebo twice-daily for 2 weeks. P-values reported are nominal. Results ENCORE enrolled 68 participants; 42 completed the OLE and entered the DBRW (AXS-12, n=22; placebo, n=20). In the OLE, participants treated with AXS-12 reported improvement in the NSAQ Ability to Concentrate item at 1 (54.8%) and 6 (58.5%) months. Participants reported improvement in concentration, assessed by PGI-C, at 1 (66.7%) and 6 (70.0%) months. Narcolepsy overall, assessed by the CGI-C, improved at 1 (90.3%) and 6 (90.2%) months; and improved at 1 (77.8%) and 6 (80.0%) months, assessed by the PGI-C. Functional impairment, assessed by the WPAI, was reduced from 53.0% at baseline to 34.0% at 1 month and 24.3% at 6 months. In the DBRW, a greater proportion of participants switched to placebo experienced worsening on the NSAQ Ability to Concentrate item (52.6% vs 14.3%; P=0.011), and PGI-C for ability to concentrate (57.9% vs 22.2%; P=0.029) at 3 weeks compared with those continuing AXS-12. A greater proportion switched to placebo also reported worsening of their narcolepsy overall (PGI-C) at 3 weeks compared with those continuing AXS-12 (52.6% vs 16.7%; P=0.024). Treatment with AXS-12 was generally well tolerated. Conclusion Long-term, open-label treatment with AXS-12 was associated with improvements in cognitive/functional domains and productivity. Randomized withdrawal to placebo led to worsening cognition and narcolepsy overall. These results further support the long-term therapeutic benefit of AXS-12 for narcolepsy. Support (if any) Axsome Therapeutics Inc.
The prevalence and incidence of narcolepsy in the United States: a real-world observational study using a validated narcolepsy case definition
Abstract Study Objectives Narcolepsy is a chronic condition affecting the sleep/wake cycle that is challenging to diagnose. Epidemiological data from large US-focused studies remain limited, with no validated claims-based case selection definitions for narcolepsy. We estimated the prevalence/incidence of diagnosed narcolepsy (type 1 [NT1], type 2 [NT2], overall) in an insured US population using validated, claims-based narcolepsy case definitions. Materials and Methods This observational study used HealthVerity administrative claims-linked electronic medical records to develop case definitions identifying individuals with NT1, NT2, and overall narcolepsy from diagnosis, medication, and procedure codes. Claims-based case definition performance (NT1, NT2, overall narcolepsy) was assessed using positive predictive values (PPVs). Prevalence (per 100 000 persons, on December 31, 2023) and annual incidence (per 100 000 person-years [PY], 2020 − 2023) were calculated/adjusted using PPVs for each case definition. Results Unadjusted point prevalence among individuals with ≥12 months of continuous enrollment were 15.5/100 000 (NT1), 51.1/100 000 (NT2), and 67.0/100 000 (overall narcolepsy). Unadjusted incidence rates were stable from 2020 − 2023 for NT1 (range, 2.0 − 2.3/100 000 PY) but declined across years for NT2 (9.1 − 7.6/100 000 PY) and overall narcolepsy (11.3 − 9.6/100 000 PY). PPVs (95% confidence interval) of NT1, NT2, and overall narcolepsy were 0.81 (0.72 − 0.88), 0.84 (0.75 − 0.91), and 0.80 (0.71 − 0.87), contributing to epidemiologic estimates being reduced by ~20% after PPV adjustment. Prevalence and incidence were higher in females than males. Individuals with NT1 were ~ 4 years younger versus NT2. Conclusions Validated definitions for narcolepsy can reduce potential misclassification. Our findings highlight a relatively low NT1 prevalence in the US. In contrast, NT2 prevalence estimates were > 3 times higher than NT1.
0843 ENCORE: Topline Results of a Phase 3 Open-Label Extension and Randomized-Withdrawal Trial of AXS-12 in Narcolepsy
Abstract Introduction AXS-12 (reboxetine) is a highly selective norepinephrine reuptake inhibitor and cortical dopamine modulator under development for narcolepsy. In the Phase 3 SYMPHONY trial, AXS-12 significantly reduced weekly cataplexy attacks from baseline to Week 5 versus placebo in patients with narcolepsy. Here we report the Phase 3 ENCORE trial, assessing long-term efficacy and safety of AXS-12 in participants who completed SYMPHONY. Methods ENCORE included a 24-week open-label extension (OLE) period, followed by a 3-week double-blind randomized-withdrawal (DBRW) period. During the OLE, participants received AXS-12 (5 mg once-daily for 1 week, twice-daily for 23 weeks). Following this, remaining participants were randomized 1:1 to continue twice-daily AXS-12 or switch to once-daily AXS-12 plus placebo for 1 week, then placebo twice-daily for 2 weeks. The primary endpoint was change in frequency of cataplexy attacks from randomization to DBRW Week 3. OLE efficacy outcomes included change in weekly frequency of cataplexy attacks, cataplexy response (≥50% reduction), and change in cataplexy-free days. Additional analyses are ongoing. Results ENCORE enrolled 68 participants; 42 completed the OLE and entered the DBRW (AXS-12, n=22; placebo, n=20). In SYMPHONY, baseline mean weekly frequency of cataplexy attacks was 31.5. At DBRW randomization, mean weekly frequency of cataplexy attacks was 4.2 (AXS-12) and 6.9 (placebo). Participants randomized to placebo experienced a mean increase of 10.29 weekly cataplexy attacks versus 1.32 for AXS-12, at end of DBRW (p=0.017). In the OLE, weekly frequency of cataplexy attacks decreased by 22.3 (71%) and 24.1 (77%) at 1 and 6 months, respectively. Cataplexy response was achieved by 72% and 82% at 1 and 6 months, respectively. Cataplexy-free days increased from 14.3% to 61% and 70% at 1 and 6 months, respectively. Common adverse events (AEs; ≥5%) during the OLE were nausea and tachycardia (both 5.9%); no new safety signals were detected. Discontinuations due to AEs occurred in 17.6% of participants in the OLE. Conclusion AXS-12 significantly reduced the frequency of cataplexy attacks during the DBRW. AXS-12 was well-tolerated and demonstrated maintenance of efficacy with long-term open-label use. These results align with SYMPHONY, supporting the positive therapeutic impact of AXS-12 for narcolepsy. Support (if any) Axsome Therapeutics, Inc.
0828 Impact of AXS-12 on Symptom Severity and Functional Impairment in Narcolepsy: Results from the Phase 3 SYMPHONY Trial
Abstract Introduction Narcolepsy is a chronic neurologic condition associated with severe symptom burden, impaired functioning and reduced quality of life. Patients commonly report comorbid mood disorders. AXS-12 (reboxetine) is a selective norepinephrine reuptake inhibitor and cortical dopamine modulator under investigation for the treatment of narcolepsy. In the Phase 3 SYMPHONY trial, AXS-12 met the primary endpoint, a statistically significant reduction in weekly cataplexy attacks from baseline to Week 5 versus placebo. Here, we report secondary endpoints assessing symptom severity, daily functioning, and mood. Methods SYMPHONY was a randomized, double-blind, placebo-controlled trial in patients with narcolepsy type 1 (NT1). Participants (15-75 years) were randomized 1:1 to AXS-12 or placebo for 5 weeks. Stable, concurrent modafinil/armodafinil use was allowed. Secondary endpoints included: the Clinical Global Impression of Severity (CGI-S) for narcolepsy, the Functional Outcomes of Sleep Questionnaire short version (FOSQ-10), and the EuroQol 5-Dimension 5-Level (EQ-5D-5L) questionnaire anxiety/depression domain. Results Ninety participants were enrolled. At baseline, mean (SD) CGI-S for narcolepsy score was 5.2 (1.0) in the AXS-12 arm and 4.9 (1.0) in the placebo arm. AXS-12 led to a significant reduction versus placebo in CGI-S for narcolepsy at Week 5 (LS mean difference [95% CI]=0.72 [0.29, 1.16]; p=0.001). At baseline, mean FOSQ-10 total score was 11.1 (3.1) in the AXS-12 arm and 11.6 (3.2) in the placebo arm. AXS-12 led to a statistically significant improvement from baseline to Week 5 in FOSQ-10 total scores compared to placebo (1.66 [0.51, 2.82], p=0.005). At baseline, 47.8% of participants in the AXS-12 arm and 45.5% in the placebo arm reported anxiety/depression (EQ-5D-5L). A numerically greater proportion of participants achieved improvements on this domain with AXS-12 (55.0%) versus placebo (31.6%) at Week 5 (p=0.146). Conclusion AXS-12 demonstrated significant reductions in clinical impressions of narcolepsy symptom severity. Functional impairment due to EDS was also significantly reduced, in-line with previously reported improvement in clinician-rated assessments. Anxiety and depression-related symptoms showed trends favoring AXS-12. Combined with prior findings on cataplexy and cognitive improvements, these results highlight the potential of AXS-12 as a therapeutic option addressing multiple symptoms of narcolepsy which affect QoL and functioning. Support (if any) Axsome Therapeutics, Inc.
0689 Exploratory Study of the Effect of Alcohol on Home Sleep Apnea Testing Utilizing Peripheral Arterial Tone
Abstract Introduction A previously published case report suggested that alcohol might cause false-negative results in home sleep apnea testing (HSAT) utilizing Peripheral Arterial Tonometry (PAT). Alcohol is consumed by nearly a third of people globally. Based on this, along with rapid growth in PAT HSAT utilization, we aimed to prospectively study the interaction between alcohol consumption and PAT HSAT technology. We hypothesized that alcohol use would significantly attenuate sleep disordered breathing metrics in contrast to existing literature suggesting alcohol may exacerbate sleep apnea. Methods We planned to recruit subjects (N=100) from Mayo Clinic Arizona sleep clinic who were being evaluated for sleep-disordered breathing and elected to undergo home sleep apnea testing (WatchPAT ONE). Participants were required to report social alcohol use (no more than 1-3 drinks per day). The first and second home sleep apnea test were conducted on separate nights (night 1: without alcohol; night 2: with alcohol). Patients also completed a questionnaire, detailing their normal alcohol intake as well as intake during the respective sleep tests. Statistical analysis included paired sample t-test as well as a descriptive analysis. Results A total of 75 subjects were recruited (mean age [± SD] 56.8 ± 11.9; 90.7% male; mean BMI 29.8 ± 5.8) and 56 patients completed both sleep tests. The mean apnea hypopnea index (AHI) was not statistically different (p=0.784) between night 1 and night 2 (without alcohol: 19.6/hour ± 21.0; with alcohol: 19.3 ± 21.5, respectively). Similarly, no statistically significant difference was found in the AHI during REM and NREM sleep. Conclusion Preliminary data does not suggest a statistically significant difference in AHI without or with alcohol. While no significant change in AHI was observed, this study highlights the need for further investigation into the impact alcohol may have on PAT technology. Further analyses and data enrichment are underway. Support (if any) Mayo Foundation
AXS-12 for the Treatment of Narcolepsy: Topline Results from the Phase 3 SYMPHONY Trial (PL5.007)