Tabuteau, Herriot

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.

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.

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.