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PRAX-628 treatment for adults with focal seizures.

A Double-Blind, Randomized, Multicenter, Trial Evaluating the Efficacy and Safety of PRAX-628 in Adults With Focal Seizures (POWER1)

Phase2; Phase3 Interventional Praxis Precision Medicines · NCT06999902

This trial will test whether once-daily PRAX-628 reduces seizure frequency and is safe in adults with focal seizures who are taking 1–3 anti-seizure medications.

Quick facts

PhasePhase2; Phase3
Study typeInterventional
Enrollment230 (estimated)
Ages18 Years to 75 Years
SexAll
SponsorPraxis Precision Medicines Industry-sponsored
Locations26 sites (Phoenix, Arizona and 25 other locations)
Trial IDNCT06999902 on ClinicalTrials.gov

What this trial studies

POWER1 is a double-blind, randomized, multicenter trial enrolling adults with focal-onset epilepsy who are concurrently taking one to three acceptable anti-seizure medications. Participants are randomized to oral PRAX-628 (20 mg/day for 6 weeks, then 30 mg/day for the remaining 6 weeks) or matching placebo, with regular visits to record seizures and monitor safety. Key inclusion requires prior imaging (CT or MRI) that rules out a progressive cause, and key exclusions include recent neurosurgery, recent VNS implantation, planned epilepsy surgery, psychogenic or uncountable cluster seizures, or a recent convulsive status epilepticus requiring hospitalization. The main outcomes are change in seizure frequency and tolerability over the 12-week dosing period.

Who should consider this trial

Good fit: Adults with a diagnosis of focal-onset epilepsy who are taking between one and three acceptable anti-seizure medications and have imaging excluding a progressive cause would be the intended participants.

Not a fit: Patients with psychogenic seizures, uncountable cluster seizures, a recent convulsive status epilepticus requiring hospitalization, planned epilepsy surgery, very recent neurosurgery or VNS implantation, or primarily non-focal seizure types are unlikely to be eligible or to benefit from this trial.

Why it matters

Potential benefit: If successful, PRAX-628 could lower seizure frequency and improve seizure control and quality of life for adults with focal epilepsy.

How similar studies have performed: Randomized, placebo-controlled trials of new oral anti-seizure medications have sometimes produced meaningful reductions in focal seizures, but PRAX-628 has limited published late-phase outcome data to date.

Eligibility criteria

Show full inclusion / exclusion criteria 
Inclusion Criteria:

1. A diagnosis of focal onset epilepsy according to the International League Against Epilepsy (ILAE) Classification of Epilepsy.
2. Past evidence by computed tomography (CT) or magnetic resonance imaging (MRI) that has ruled out a progressive cause of epilepsy in the judgement of the investigator and/or in consultation with the medical monitor.

Exclusion Criteria:

1. Subject has had any of the of the following within the 12-month period preceding trial entry: History of pseudo or psychogenic seizures, cluster seizures where the individual seizures cannot be counted, an episode of convulsive status epilepticus requiring hospitalization and intubation, or subject only has focal seizures with awareness that do not have motor activity.
2. Planned epilepsy surgery during the course of the clinical trial.
3. History of neurosurgery for seizures \<1 year prior to enrollment, or radiosurgery \<2 years prior to enrollment or vagus nerve stimulation (VNS) implantation.
4. History of schizophrenia, obsessive-compulsive disorder, or other serious mental health disorders.
5. History of malignancy, myeloproliferative or lymphoproliferative disorders within the past 5 years are excluded.
6. History of cardiac disease(s)/cardiac conduction disorders/or cardiac structural abnormality(ies).
7. Has a positive test result or a known history of a positive test result for human immunodeficiency virus (HIV), hepatitis B surface antigen (HBsAg), or anti-hepatitis C virus (HCV) antibody at Screening.
8. Is pregnant or is breastfeeding at the time of Screening or has a positive serum pregnancy test at Screening or is planning to become pregnant during the clinical trial or within 14 days of the last study drug dose.
9. Has received any other experimental or investigational drug, device or other therapy within 30 days or 5 half-lives (whichever is longer) prior to Screening, or any prior use of gene therapy.

Where this trial is running

Phoenix, Arizona and 25 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
View on ClinicalTrials.gov → Find more trials like this →
Conditions Focal Seizure
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.