Praxis AES Wrap-up: Best-in-Class Potential Across Rare Pediatric and Adult Epilepsies
Rhea-AI Summary
Praxis (NASDAQ: PRAX) reported clinical updates presented at AES on December 6, 2025, covering relutrigine (EMBOLD) and vormatrigine (RADIANT).
EMBOLD: relutrigine (n=51) produced a 53% placebo‑adjusted seizure reduction over 16 weeks (p<0.0002), a 66% increase in motor seizure‑free days (p=0.034), broad functional improvements, and no drug‑related serious adverse events; Praxis will meet the FDA to discuss an NDA and then decide filing timing.
RADIANT: vormatrigine (FOS n=62) delivered a 54% median seizure reduction at 8 weeks, 58% ≥50% responders in week 1 rising to 61% by week 8, with 100% median weekly seizure reduction by week 8 maintained to 16 weeks; generalized epilepsy cohort (n=3) showed similar effects. POWER1 recruiting complete; POWER2 on track to finish H2 2026; POWER3 monotherapy to start H1 2026.
Positive
- Relutrigine: 53% placebo‑adjusted seizure reduction over 16 weeks
- Relutrigine: 66% increase in motor seizure‑free days
- No drug‑related serious adverse events reported for relutrigine
- Vormatrigine FOS: 54% median seizure reduction at 8 weeks
- Vormatrigine reached 100% median weekly seizure reduction by week 8
Negative
- EMBOLD relutrigine cohort size was modest at n=51
- RADIANT generalized epilepsy cohort was very small at n=3
- Only ~11% experienced seizure freedom for the entire 8‑week period
- NDA timing undecided pending upcoming FDA meeting
Key Figures
Market Reality Check
Peers on Argus
PRAX gained 29.28% while close biotech peers showed mixed, mostly modest moves (e.g., EYPT +5.22%, ZBIO +2.9%, AVXL -0.68%, NKTR -1.88%, SANA -0.39%). This points to a stock-specific reaction to the epilepsy updates rather than a broad sector rotation.
Historical Context
| Date | Event | Sentiment | Move | Catalyst |
|---|---|---|---|---|
| Dec 04 | Clinical data update | Positive | +3.0% | Positive EMBOLD topline relutrigine data and upcoming FDA meeting plans. |
| Dec 04 | Regulatory update | Positive | +3.0% | Pre-NDA meeting for ulixacaltamide with expected NDA submission early 2026. |
| Dec 03 | Equity compensation | Neutral | +3.9% | Inducement RSU grants to new hires under 2024 Inducement Plan. |
| Nov 24 | Conference preview | Positive | -3.5% | Plan to present extensive epilepsy portfolio data at AES meeting. |
| Nov 20 | Investor event | Positive | -13.3% | Announcement of HC Wainwright fireside chat on ulixacaltamide data. |
Recent positive clinical and corporate updates have often produced modest gains, but today’s move is much larger; negative reactions have appeared around event communications and data discussions despite constructive messaging.
Over the past few weeks, PRAX has reported multiple advances across its neurology pipeline. On Nov 20, a fireside chat on ulixacaltamide coincided with a -13.33% move, and on Nov 24 AES presentation plans saw a -3.46% reaction. In early December, positive EMBOLD relutrigine data and a favorable pre‑NDA interaction for ulixacaltamide each saw about 3.05% gains, while an inducement grant filing on Dec 03 coincided with a 3.93% rise. Today’s AES wrap-up deepens the epilepsy story following those earlier updates.
Market Pulse Summary
This announcement consolidates key AES updates on relutrigine in DEEs and vormatrigine in focal onset and generalized epilepsies, highlighting seizure reductions up to 53% placebo-adjusted for relutrigine and strong responder rates for vormatrigine. It follows recent positive EMBOLD topline news and a constructive pre‑NDA interaction for ulixacaltamide, alongside increased R&D spending and a substantial October equity financing. Investors may watch future FDA meetings, NDA timing, pivotal POWER studies, and continued safety data as the epilepsy portfolio advances.
Key Terms
developmental and epileptic encephalopathies medical
new drug application (NDA) regulatory
focal onset seizures medical
generalized epilepsy medical
antisense oligonucleotide medical
AI-generated analysis. Not financial advice.
Positive Results in the EMBOLD study of relutrigine showed a
(p < 0.0002),
Patients in the RADIANT study of vormatrigine showed rapid, consistent and durable improvement in seizure reduction, reaching
Expansion of the Praxis Analysis of Concordance Framework to include DEEs
Showcase of the most comprehensive epilepsy portfolio
BOSTON, Dec. 08, 2025 (GLOBE NEWSWIRE) -- Praxis Precision Medicines, Inc. (NASDAQ: PRAX), a clinical-stage biopharmaceutical company translating genetic insights into the development of therapies for central nervous system (CNS) disorders characterized by neuronal excitation-inhibition imbalance, today provided clinical updates shared at the American Epilepsy Society Annual Meeting (AES) on December 6, 2025.
“The updates we shared at AES mark a pivotal moment for epilepsy treatment. The EMBOLD results highlight the long-awaited potential of relutrigine to become the first disease modifying treatment for SCN2A and SCN8A-DEE patients and show that we are positioned to deliver the same impact for the broader DEE community,” said Marcio Souza, president and chief executive officer. “Additionally, the update from the RADIANT study for focal-onset seizures and generalized epilepsy confirmed its potential as a best-in-class therapy. We are committed to accelerating these options to patients while continuing to accelerate the broad DEE study, EMERALD, our ASO programs and the FOS studies toward registration.”
Relutrigine for Developmental and Epileptic Encephalopathies (DEEs):
At AES, Praxis shared results [link to poster] of the EMBOLD study, demonstrating relutrigine was well-tolerated with rapid, significant and increasing seizure reduction over time with broad functional improvements across behavior, alertness, communication and overall status. Praxis will meet with the FDA in the coming weeks to discuss next steps for the New Drug Application (NDA). Praxis will make a determination of the timing for filing the NDA after the meeting.
- Patients receiving relutrigine (n=51) experienced a
53% placebo-adjusted reduction in seizures over 16-weeks (p<0.0002) - Patients achieved a
66% increase in motor seizure-free days (p=0.034) - Both clinician and caregiver global impression scores showed statistically significant improvements, with most patients improving across both scales in alertness, communication, and seizure severity.
- There were no drug-related serious adverse events and treatment-related adverse events were predominantly mild and moderate.
Vormatrigine for Focal Onset Seizures (FOS) and Generalized Epilepsy: RADIANT results [link to poster] position vormatrigine as a best-in-disease therapy: fast-acting efficacy without titration, sustained reduction over longer treatment duration, seizure-freedom potential, favorable DDI, tolerability and safety profiles with once-daily dosing.
Focal Onset Seizures (n=62)
- Patients taking vormatrigine for 8 weeks on background anti-seizure medications (ASM) saw a
54% median reduction in seizures. - In week 1,
58% of patients achieved at least a50% reduction in seizures, which increased to61% by week 8. - Increasing and sustained effect was observed, with FOS patients reaching
100% median weekly seizure reduction after 8 weeks and maintained through 16 weeks. - Over
11% of patients experienced seizure freedom for the entire 8-week period and roughly one third of patients experienced seizure freedom for a consecutive 28-day period.
Generalized Epilepsy (n=3)
- Three patients with generalized epilepsy included in the cohort experienced a similar treatment effect as FOS patients, with rapid, durable seizure reduction.
Praxis has completed recruiting for the POWER1 pivotal study in FOS and is on track to complete the POWER2 study in the second half of 2026. The monotherapy study, POWER3, is on track to begin in the first half 2026. Additional posters presented at AES at Resources - Praxis Medicines
About Vormatrigine (PRAX-628)
Vormatrigine is a next-generation, functionally selective small molecule targeting the hyperexcitable state of sodium-channels in the brain that is currently being developed as a once daily, oral treatment for adult focal onset seizures and generalized epilepsy. Preclinical data demonstrates vormatrigine is differentiated from standard of care, with the potential to be best-in-class for focal epilepsy. In vitro, vormatrigine has demonstrated superior selectivity for disease-state NaV channel hyperexcitability. In vivo studies of vormatrigine have demonstrated unprecedented potency in the maximal electroshock seizure (MES) model, a highly predictive translational model for efficacy in focal epilepsy. Data from the first cohort of patients in the RADIANT study demonstrated a robust seizure reduction and generally safe and well tolerated profile. To learn more about the POWER1 and POWER2 studies, please visit POWER1 study.
About Relutrigine (PRAX-562)
Relutrigine is a first-in-class small molecule in development for the treatment of developmental and epileptic encephalopathies (DEEs) as a preferential inhibitor of persistent sodium current, shown to be a key driver of seizure symptoms in severe DEEs. Relutrigine’s mechanism of precision sodium channel (NaV) modulation is consistent with superior selectivity for disease-state NaV channel hyperexcitability. In vivo studies of relutrigine have demonstrated dose-dependent inhibition of seizures up to complete control of seizure activity in SCN2A, SCN8A and other DEE mouse models. Relutrigine has been generally well-tolerated in three Phase 1 studies and has demonstrated biomarker changes indicative of NaV channel modulation. Data from cohort 1 of the Phase 2 EMBOLD study demonstrated a well-tolerated, robust, short- and long-term improvement in motor seizures in a heavily pre-treated population, alongside maintained seizure freedom in some patients with SCN2A- and SCN8A-DEE. Relutrigine has received Orphan Drug Designation (ODD) and Rare Pediatric Disease Designation from the FDA for the treatment of SCN2A-DEE, SCN8A-DEE and Dravet syndrome; as well as Breakthrough Therapy Designation (BTD), and ODD from the European Medicines Agency for the treatment of SCN2A-DEE and SCN8A-DEE. To learn more about the EMERALD and EMBOLD studies, please visit ResilienceStudies.com.
About Praxis
Praxis Precision Medicines is a clinical-stage biopharmaceutical company translating insights from genetic epilepsies into the development of therapies for CNS disorders characterized by neuronal excitation-inhibition imbalance. Praxis is applying genetic insights to the discovery and development of therapies for rare and more prevalent neurological disorders through our proprietary small molecule platform, Cerebrum™, and antisense oligonucleotide (ASO) platform, Solidus™, using our understanding of shared biological targets and circuits in the brain. Praxis has established a diversified, multimodal CNS portfolio including multiple programs across movement disorders and epilepsy, with four clinical-stage product candidates. For more information, please visit www.praxismedicines.com and follow us on Facebook, LinkedIn and Twitter/X.
Forward-Looking Statements
This press release contains forward-looking statements within the meaning of The Private Securities Litigation Reform Act of 1995 and other federal securities laws, including express or implied statements regarding Praxis’ future expectations, plans and prospects, including, without limitation, statements regarding the anticipated timing of our clinical trials, the development of our product candidates and the anticipated timing of regulatory submissions and interactions, as well as other statements containing the words “anticipate,” “believe,” “continue,” “could,” “endeavor,” “estimate,” “expect,” “anticipate,” “intend,” “may,” “might,” “plan,” “potential,” “predict,” “project,” “seek,” “should,” “target,” “will” or “would” and similar expressions that constitute forward-looking statements under the Private Securities Litigation Reform Act of 1995.
The express or implied forward-looking statements included in this press release are only predictions and are subject to a number of risks, uncertainties and assumptions, including, without limitation: uncertainties inherent in clinical trials; preliminary analyses from ongoing studies differing materially from final data from preclinical studies and completed clinical trials; the expected timing of clinical trials, data readouts and the results thereof, and submissions for regulatory approval or review by governmental authorities; regulatory approvals to conduct trials; and other risks concerning Praxis’ programs and operations as described in its Annual Report on Form 10-K for the year ended December 31, 2024 and as updated in the Quarterly Report on Form 10-Q for the period ended June 30, 2025, as well as other filings made with the Securities and Exchange Commission. Although Praxis’ forward-looking statements reflect the good faith judgment of its management, these statements are based only on information and factors currently known by Praxis. As a result, you are cautioned not to rely on these forward-looking statements. Any forward-looking statement made in this press release speaks only as of the date on which it is made. Praxis undertakes no obligation to publicly update or revise any forward-looking statement, whether as a result of new information, future developments or otherwise.
Investor Contact: Praxis Precision Medicines investors@praxismedicines.com 857-702-9452 Media Contact: Dan Ferry Life Science Advisors Daniel@lifesciadvisors.com 617-430-7576
FAQ
What did Praxis report for relutrigine in the EMBOLD study (PRAX) on Dec 6, 2025?
When will Praxis (PRAX) decide on filing an NDA for relutrigine?
What were the key RADIANT results for vormatrigine in focal‑onset seizures (PRAX)?
Are there safety signals for relutrigine or vormatrigine reported at AES (PRAX)?
What is the status and timing of Praxis POWER pivotal studies for vormatrigine (PRAX)?
How many patients achieved sustained seizure freedom in the RADIANT focal‑onset cohort (PRAX)?
