A Study to Test the Effectiveness and Safety of Experimental Padsevonil for Seizures in Adults With Drug-Resistant Epilepsy
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Age: 18 years or older
Healthy Volunteers: No
Keywords: Drug-Resistant Epilepsy, seizures, Focal-Onset Seizures
Type: Drug study, Phase 3
5 Participants
Seizures are caused by abnormal electrical disturbances in the brain. Focal-onset seizures occur when this electrical activity remains in a limited area of the brain. Seizures can sometimes turn into generalized seizures (also called Grand Mal seizures), which affect the whole brain.

The purpose of this study is to test the effectiveness, safety, and tolerability of a new experimental drug called padsevonil. The study drug will be given in one of 3 different doses along with your current epilepsy treatment that may consist of 1-3 antiepileptic drugs. The study also aims to see how safe padsevonil is compared to placebo and how well your body can tolerate it.

This study involves the use of both padsevonil and placebo tablets that look exactly the same. The placebo does not contain any active ingredients. Placebo as well might have effect on your seizures and wellbeing.

You have an equal chance (like rolling a dice) of being assigned to one of the 4 treatment groups:
- padsevonil 200 mg/day,
- padsevonil 400 mg/day,
- padsevonil 800 mg/day or
- placebo.

Padsevonil is a medicine particularly made to better control seizures in people who are resistant to other anti-seizure drugs. It has not yet been approved by drug authorities such as FDA, for the treatment of any disease, including focal-onset seizures.
This study requires

The study team will make sure you qualify to take part in the study. Qualified participants will receive detailed information about the study. This may include a list of study-related tests and procedures.

Who can participate

Inclusion criteria:

  • Diagnosis of focal epilepsy per 1989 International League Against Epilepsy (ILAE) criteria at least 3 years before study entry
  • Subject has failed to achieve seizure control with >=4 tolerated and appropriately chosen prior antiepileptic drugs (AED), including past and ongoing treatment, that were individually optimized for adequate dose and duration. Prior discontinued AED treatment would need to be assessed by the Investigator considering the patient medical records and patient and/or caregiver interview. 'Prior AED' is defined as all past and ongoing AED treatments with a start date before the Screening Visit (Visit 1)
  • Average of >= 4 spontaneous and observable focal seizures (type IA1 (i.e. focal aware), IB (i.e. focal impaired awareness), IC (i.e. focal to bilateral tonic-clonic)) per month
  • Current treatment with an individually optimized and stable dose of at least 1 and up to 3 AEDs for the 8 weeks prior to the Screening Visit with or without additional Vagus Nerve Stimulation (VNS) or other neurostimulation treatments

Exclusion criteria:

  • Subject has a history of or signs of generalized or combined generalized and focal epilepsy
  • Cluster seizures which are uncountable in the previous 8 weeks before study entry and during 4 weeks prospective baseline
  • Current treatment with carbamazepine, phenytoin, primidone, phenobarbital
  • Current treatment/ use of (non-AED) prescription, nonprescription, dietary (eg, grapefruit or passion fruit), or herbal products that are potent inducers or inhibitors of the CYP3A4 or 2C19 pathway for 2 weeks (or 5 half-lives, whichever is longer) prior to the Baseline Visit
  • Subjects taking sensitive substrates of CYP2C19 for 2 weeks (or 5 half-lives, whichever is longer) prior to the Baseline Visit
  • Subject has been taking vigabatrin less than 2 years at study entry
  • Subject has been taking felbamate for less than 12 months
  • Subject taking retigabine for less than 4 years
  • Current treatment with benzodiazepines (i.e. GABA-A-ergic drugs like zolpidem, zaleplon, or zopiclone, excluding GABA-A-ergic AEDs) <3 times per week for emergencies
  • Subject has a current medical condition that occurred within the last 12 months which, in the opinion of the investigator, could compromise his/her safety or ability to participate in this study
Benefits and risks of participating

We cannot promise any benefits to you as a result of taking part in this research study.


The study doctor will discuss the risks associated with taking part in this research study.
If you agree to take part in this research study, we will compensate you $54 for each study visit you complete. You will be paid in the form of a check mailed to your home after each completed study visit.
Study duration and period
Your participation in this study could last up to 27 weeks. There will be a Baseline Period of 4 weeks. The Treatment Period will last a maximum of 16 weeks. A Conversion or Taper Period of 3 to 4 weeks will follow. The Safety Follow-up Visit will be performed 30 days after you took the last study drug (padsevonil or placebo).
Recruitment period
From Jan. 29, 2020
UC Davis Medical Center
2315 Stockton Boulevard
Sacramento, CA 95817
Kishchenko, Olga
Research Topic
  • Drug-Resistant Epilepsy
  • Focal-Onset Seizures

Have any questions or want to learn more? Leave your contact details below and the research team will reach out to you.


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