0843 ENCORE: Topline Results of a Phase 3 Open-Label Extension and Randomized-Withdrawal Trial of AXS-12 in Narcolepsy
Bibliographic record
Abstract
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.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.002 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.013 | 0.002 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".