CHAMGAP
APPROVEDReviewed and approved by the Chamgap Editorial Team (2026-07-23). The draft was written by AI, the existence of all 2 cited sources was verified at the original page, and the verdict passed blind grading and adversarial audit. Methodology v0.6.
Verdict No. 1325 · Search date 2026-07-23 · Methodology v0.6

Cenobamate,
does it really help with Complete seizure freedom as adjunctive therapy for focal seizures uncontrolled by existing medicines in adults?

30-Second Summary
C
Evidence Grade C · 58 · Safety unknown
Cenobamate increased short-term complete freedom in uncontrolled focal seizures, but independent long-term replication is limited
What the
research shows
Cenobamate is rated C because adjunctive treatment increased short-term complete seizure freedom in adults whose focal seizures remained uncontrolled on existing antiseizure medicines. In a 222-participant phase 2 trial, seizure freedom during the six-week maintenance phase was 28.3% versus 8.8% with placebo, and median seizure-frequency reduction was 55.6% versus 21.5%. The small sample, short maintenance period, manufacturer support, and limited independent replication of long-term complete freedom yield C with 58 points.
What the
ads claim
Six-week complete seizure freedom can be expanded into a long-term cure for drug-resistant epilepsy or permission to stop existing medicines. Use requires slow titration, adjustment of concomitant medicines, and continued follow-up.
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Useful facts when choosing a product

  • Cenobamate is an oral prescription antiseizure medicine for focal-onset seizures in adults; the evidence in this verdict concerns addition to existing treatment.
  • To reduce DRESS risk, treatment commonly starts at 12.5 mg daily and increases every two weeks, and it should not be stopped abruptly without supervision.
  • Somnolence, dizziness, fatigue, diplopia, and impaired gait or coordination are common and can worsen with alcohol or other sedatives.
  • It shortens the QT interval and is contraindicated in familial short-QT syndrome; CYP2C19 inhibition and CYP3A induction can require adjustment of concomitant antiseizure medicines.
Gap Measurement · Verdict 1325 · C 58
What advertising claims
What independent, higher-quality research supports
△ GAP
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What the research actually shows

Chung and colleagues randomized 222 adults with uncontrolled focal seizures despite one to three antiseizure medicines to cenobamate 200 mg daily or placebo under double masking. Complete seizure freedom during the six-week maintenance phase was 28.3% versus 8.8%, and median seizure-frequency reduction over the double-blind period was 55.6% versus 21.5%. In a separate 437-participant dose-ranging trial, at least 50% response rates were 25% with placebo and 40%, 56%, and 64% with 100, 200, and 400 mg, with dose-related maintenance-phase seizure freedom.

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Why this is classified as C (58)

Seizure freedom of 28.3% versus 8.8% and frequency reduction were positive, but 222 participants, six maintenance weeks, manufacturer support, and limited independent long-term replication yield C with 58 points.

Counterpoint. The chance of complete freedom matters for treatment choice, but a specialist must titrate while tracking seizures, adverse effects, and interactions.

Rejudgment record. Cross-check applied — Accepted complete seizure freedom and frequency reduction with placebo-controlled adjunctive therapy in adults uncontrolled by existing medicines, while reflecting that the pivotal freedom estimate came from a six-week maintenance phase in 222 participants with manufacturer support and limited independent long-term replication

Sub-claim grades by effect

This ingredient is marketed for several effects. A single overall grade blends strong and weak claims together, so each effect is graded separately here. The overall grade reflects the strongest disconfirming or core claim.

Effect (sub-claim)GradeBasis
Complete seizure freedom during maintenanceCIt was 28.3% versus 8.8% over the six-week maintenance phase in the 222-participant trial.
Reduced focal-seizure frequencyCMedian frequency reduction was 55.6% versus 21.5%, with replication in a separate dose-ranging trial.
Increased response of at least 50% seizure-frequency reductionCIn the dose-ranging trial, response was 25% with placebo versus 56% at 200 mg and 64% at 400 mg.

Cross-check — Codex and Claude

This verdict was drafted by Codex through literature review and source-existence checks, cross-checked through blind grading and adversarial audit, and settled by reapplying the methodology boundary rules. Cases with split grades were resolved through rejudgment.
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Evidence Table

StudyDesignSampleFundingEndpointResultWeight
Study 1Multicenter randomized double-blind placebo-controlled phase 2 trial222Supported by SK Life ScienceSeizure-frequency change, 50% response, and complete seizure freedom during six maintenance weeksMaintenance-phase seizure freedom 28.3% versus 8.8%; median frequency reduction 55.6% versus 21.5%.Pivotal short-term seizure-freedom trial
Study 2Multinational randomized double-blind placebo-controlled dose-response trial437Supported by SK Life ScienceSeizure-frequency change and at least 50% responseMaintenance-phase 50% response was 25% with placebo versus 40%, 56%, and 64% with 100, 200, and 400 mg.Dose-response randomized replication
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Receipt — 2 References

All 2 cited sources were verified for existence at the original page (as of 2026-07-23).

Chung SS, French JA, Kowalski J, et al. Randomized phase 2 study of adjunctive cenobamate in patients with uncontrolled focal seizures. Neurology. 2020;94(22):e2311-e2322. PMID: 32409485. PMCID: PMC7357293. DOI: 10.1212/WNL.0000000000009530.
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Krauss GL, Klein P, Brandt C, et al. Safety and efficacy of adjunctive cenobamate (YKP3089) in patients with uncontrolled focal seizures: a multicentre, double-blind, randomised, placebo-controlled, dose-response trial. Lancet Neurol. 2020;19(1):38-48. PMID: 31734103. DOI: 10.1016/S1474-4422(19)30399-0.
checked
Draft and rewrite: Codex (AI) · Verification: Codex blind grading and adversarial audit · Final adjudication: Claude
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-07-23 · Corrections: none

Cite this verdict

Cenobamate x seizure freedom as adjunctive therapy for uncontrolled focal seizures in adults Evidence Grade C card
[Chamgap] Cenobamate x seizure freedom as adjunctive therapy for uncontrolled focal seizures in adults — Evidence Grade C·58. 2 cited sources checked. Source: https://chamgap.com/en/verdicts/cognition/cenobamate-adjunctive-uncontrolled-focal-seizure-freedom/ · CC BY 4.0

CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.

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What this document does and does not do

Chamgap is an information source. It reports what research has and has not confirmed; it does not tell readers what to take or buy. That decision belongs to readers and, when needed, medical or legal professionals. This verdict reflects literature available up to the search date and may change as new research appears. Nothing here is medical advice.