PRX-00023 Therapy in Localization-Related Epilepsy

This study is currently recruiting participants. (see Contacts and Locations)
Verified April 2016 by National Institutes of Health Clinical Center (CC)
Information provided by (Responsible Party):
National Institutes of Health Clinical Center (CC) ( National Institute of Neurological Disorders and Stroke (NINDS) ) Identifier:
First received: January 21, 2011
Last updated: May 11, 2016
Last verified: April 2016


- The brain chemical serotonin helps nerve cells communicate. Previous research suggests that serotonin activity may be lower in brain areas where seizures start, and that increasing activity at the serotonin receptor site on nerve cells may help prevent seizures. Researchers are interested in determining whether the experimental medication PRX-00023, which increases the activity of serotonin receptors, can reduce seizure frequency in people whose seizures are not well-controlled on antiseizure medication. PRX-00023 has not previously been studied in people with epilepsy and has not previously been given to people taking antiseizure medication at the same time.


- To evaluate the effectiveness of PRX-00023 in reducing the frequency of epileptic seizures that start from only one part of the brain.


- Individuals between 18 and 65 years of age who have frequent epileptic seizures even after trying at least two different standard anti-seizure medications (either at the same time or one after the other).


  • The study requires 9 outpatient visits to the NIH Clinical Center over a 34-week period. Individuals who choose to participate in additional studies may be an inpatient during some of these visits.
  • Participants will be screened with a medical history and physical examination, blood and urine samples, ECG, EEG, neuropsychological studies, imaging studies, including PET and MRI scans
  • Participants will have a 6-week observation and evaluation period before starting the study medication. Participants who have at least four seizures during this period will be eligible for the treatment portion of the study.
  • All participants will receive either PRX-00023 or a placebo pill twice daily for 12 weeks, and will have regular clinic visits with blood samples and imaging studies.
  • After the 12-week period, participants will have a 2- to 3-week washout period without any study medication.
  • Participants will then have another study medication period, and will receive the opposite pill (PRX-00023 or placebo) from the one taken in the first treatment phase. Participants will continue to have regular clinic visits with blood samples, ECG, EEG and neuropsychologicalstudies.
  • One month after the end of the second study medication phase, participants will have a followup evaluation with a physical examination, blood tests, ECG, EEG, mood and neuropsychological tests.

Outcome measures:

The primary outcome measure for drug efficacy will be:

Mean difference in seizure frequency comparing the active and placebo periods.

Secondary outcome measures for efficacy will be:

Proportion of patients with greater than or equal to 50% lower seizure rate on PRX-00023 than placebo

Hamilton Depression and Anxiety Rating scales

Performance on mood and neuropsychological testing scales

Condition Intervention Phase
Epilepsy, Temporal Lobe
Partial Epilepsy
Drug: PRX-00023
Phase 2

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Crossover Assignment
Masking: Double Blind (Subject, Investigator)
Primary Purpose: Treatment
Official Title: A Phase II Clinical Trial of PRX-00023 Therapy in Localization-Related Epilepsy

Resource links provided by NLM:

Further study details as provided by National Institutes of Health Clinical Center (CC):

Primary Outcome Measures:
  • Seizure frequency counts during the 3 month placebo and active treatment phases [ Time Frame: End of each phase ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Proportion of patients with greater than or equal to 50% lower seizure rate on PRX-0023 than placebo, Hamilton Depression and Anxiety Rating scales, and performance on neuropsychological testing scales. [ Time Frame: End of each phase ] [ Designated as safety issue: No ]
  • Safety assessment for adverse events, changes in vital signs, laboratory test results and physical examination. [ Time Frame: 6 Visits ] [ Designated as safety issue: Yes ]

Estimated Enrollment: 30
Study Start Date: January 2011
Estimated Study Completion Date: August 2017
Estimated Primary Completion Date: August 2017 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Phase I
selective 5HT1A agonist or placebo x3 months
Drug: PRX-00023
selective 5HT1A agonist or placebo
Experimental: Phase II
selective 5HT1A agonist or placebo x3 months
Drug: PRX-00023
selective 5HT1A agonist or placebo

Detailed Description:


PRX-00023 is a selective 5HT1A agonist being developed as an oral therapeutic treatment for epilepsy.


To initiate a pilot clinical trial assessing the safety, tolerability and efficacy of the 5HT1A receptor agonist PRX-00023 in patients with localization-related epilepsy. PRX-00023 is a 5HT1A receptor agonist that has shown promise in clinical trials of depression. Patients with localization-related epilepsy have reduced 5HT1A receptor binding on 18FCWAY positron emission tomography (PET). Increasing neurotransmitter activity at 5HT1A receptor sites might ameliorate seizures. Moreover, depression is a common co-morbidity in people with epilepsy. Altered 5HT1A receptor binding has been found in depression.

Study Population:

Thirty adults with localization-related epilepsy.


A randomized, double-blind, placebo-controlled cross-over, phase II clinical trial. Subjects will be screened under protocol 01-N-0139 and will undergo medical and epilepsy history and physical examination, vital signs, ECG, clinical laboratory studies including standard clinical chemistry and hematology studies, urinalysis, pregnancy test for females of childbearing potential, and MRI scan and eo EEG monitoring will be performed if not previously completed successfully, and measurement of plasma AED levels (for those AEDs in which an assay is available at NIH).

The trial will have a baseline phase, which will last up to 6 weeks. Baseline may occur concurrent with screening procedures. The baseline phase will include measurement of seizure frequency (patient will record via seizure calendar). In addition the following will be administered, unless previously completed: Columbia Suicide Severity Rating Scale, neuropsychological and mood evaluations, FCWAY PET (if not already performed), EEG, measurement of plasma AED levels (if assay available), and pregnancy test (for women of child bearing potential), saliva samples will be obtained for genetic testing (if not previously obtained) and blood samples will be obtained during the PET procedure for cortisol and ACTH levels.

Following baseline, patients will begin the treatment phase (consisting of Period 1 and Period 2). Patients will be randomized to PRX-00023 (120mg BID) or matching placebo. After completion of the first treatment period, patients will undergo a washout period after which patients will be crossed over to the alternate treatment period.

Outcome measures:

  1. Seizure frequency counts during the 3-month placebo and active treatment phases
  2. Neuropsychological and mood indices
  3. Safety assessment will include adverse events, vital signs, laboratory signs and physical examination.

Ages Eligible for Study:   18 Years to 65 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No

    1. Enrolled in protocol 01-N-0139
    2. Age 18 to 65
    3. Localization-related epilepsy diagnosed by standard clinical criteria that has not responded to treatment with up to two standard antiepileptic drugs either sequentially or in combination.
    4. Patients must be able to provide informed consent.
    5. Patients must be able to remain on their baseline AED drugs and doses for the duration of the study
    6. Patients must be able to use seizure calendars to record seizures throughout the trial.
    7. Experiences 4 seizures within a 6-week period


  1. Pregnancy or lactation
  2. Women of child-bearing potential and men who are unable or unwilling to take adequate contraceptive precautions, including one of the following:

    • hormonal contraception (birth control pills, injected hormones or vaginal ring);
    • intrauterine device;
    • barrier methods (condom or diaphragm) combined with spermicide;
    • surgical sterilization (hysterectomy, tubal ligation, or vasectomy in a partner
  3. Current treatment for another significant medical disorder, such as diabetes, or heart disease, or an untreated disorder, that is discovered during the screening examination and might interfere with the study and is determined by the PI to warrant exclusion of the participant.
  4. An abnormality on clinical laboratory tests, physical examination, EEG or ECG that might increase the risk associated with trial participation or investigational product administration, such as hepatic enzyme elevation greater than twice normal, or hematocrit lower than 30.
  5. A level 4 or 5 on the Columbia Suicide Severity Rating Scale rating for symptoms during the last month
  6. Concomitant treatment with more than 2 AEDs
  7. Evidence for a potentially progressive neurologic disorder, such as an astrocytoma
  8. Use of sublingual lorazepam for seizure clusters more than once per wee
  9. Use of any of the following prohibited medications/classes with less than required interval period:

    • Any other Investigational drugs; required interval period (weeks prior to baseline) is 4
    • benzodiazepines; required interval period (weeks prior to baseline) is 4
    • MAO Inhibitors anti depressant; required interval period (weeks prior to baseline) is 4
    • Buspirone; required interval period (weeks prior to baseline) is 2
    • other psychotropic medicines; required interval period (weeks prior to baseline) is 2
    • potent CYP3A4 inducers/inhibitors; required interval period (weeks prior to baseline) is 2 for:

      • Itraconazole
      • ketoconazole
      • HIV antivirals
      • clarithromycin
      • phenytoin
    • Prornolol is 2
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01281956

Contact: Tamika Mason (301) 496-1923
Contact: William H Theodore, M.D. (301) 496-1505

United States, Maryland
National Institutes of Health Clinical Center, 9000 Rockville Pike Recruiting
Bethesda, Maryland, United States, 20892
Contact: For more information at the NIH Clinical Center contact Patient Recruitment and Public Liaison Office (PRPL)    800-411-1222 ext TTY8664111010   
Sponsors and Collaborators
National Institute of Neurological Disorders and Stroke (NINDS)
Principal Investigator: William H Theodore, M.D. National Institute of Neurological Disorders and Stroke (NINDS)
  More Information

Additional Information:
Responsible Party: National Institutes of Health Clinical Center (CC) ( National Institute of Neurological Disorders and Stroke (NINDS) ) Identifier: NCT01281956     History of Changes
Other Study ID Numbers: 110039  11-N-0039 
Study First Received: January 21, 2011
Last Updated: May 11, 2016
Health Authority: United States: Federal Government

Keywords provided by National Institutes of Health Clinical Center (CC):
Drug Trial
Serotonin 1A Receptor
Temporal Lobe Epilepsy
Partial Epilepsy

Additional relevant MeSH terms:
Epilepsies, Partial
Epilepsy, Temporal Lobe
Brain Diseases
Central Nervous System Diseases
Nervous System Diseases
Molecular Mechanisms of Pharmacological Action
Neurotransmitter Agents
Physiological Effects of Drugs
Serotonin 5-HT1 Receptor Agonists
Serotonin Agents
Serotonin Receptor Agonists processed this record on May 26, 2016