A Study of the Efficacy and Safety of Topiramate in Epilepsy Patients With Primary Generalized Tonic-Clonic Seizures
Information source: Johnson & Johnson Pharmaceutical Research & Development, L.L.C.
Information obtained from ClinicalTrials.gov on June 20, 2008
Link to the current ClinicalTrials.gov record.
Condition(s) targeted: Seizures; Epilepsy
Intervention: topiramate (Drug)
Phase: Phase 3
Sponsored by: Johnson & Johnson Pharmaceutical Research & Development, L.L.C.
Official(s) and/or principal investigator(s):
Johnson & Johnson Pharmaceutical Research and Development, L.L.C. Clinical Trial, Study Director, Affiliation: Johnson & Johnson Pharmaceutical Research & Development, L.L.C.
The purpose of this study is to evaluate the efficacy and safety of topiramate as an add-on
therapy in epilepsy patients with uncontrolled primary generalized tonic-clonic seizures, who
are taking 1 or 2 standard antiepileptic drugs.
Official title: Topiramate Clinical Trial in Primary Generalized Tonic-Clonic Seizures
Study design: Treatment, Randomized, Double-Blind, Placebo Control, Parallel Assignment, Safety/Efficacy Study
Primary outcome: Percent reduction from baseline in primary generalized tonic-clonic seizure rates and percent responders (>=50% reduction in PGTC seizure rate from baseline), during the double-blind phase. Subjects' global evaluation of improvement in seizure severity.
Secondary outcome: Percent reduction from baseline of all seizure types and percent of treatment responders in all seizure types, during the double-blind phase. Safety evaluations conducted throughout the study.
Epilepsy is a disease characterized by seizures, which are abnormal electrical discharges in
the brain that temporarily disrupt normal brain function. Seizures are classified as
"generalized," involving all or most of the brain at the same time, or "partial onset,"
starting in one area of the brain. Generalized tonic-clonic seizures are also referred to as
grand mal seizures and are common in people with generalized epilepsy in which the cause is
not known. In a tonic-clonic seizure, the person loses consciousness, the body stiffens
(tonic phase), and then the individual falls to the ground. This is followed by jerking
movements in which the muscles contract and relax quickly (clonic phase). After a minute or
two, the jerking movements usually stop, and the person regains consciousness. Antiepileptic
medications, such as topiramate, are selected based on a patient's seizure type. Topiramate
is a drug that is currently widely used for the treatment of seizures in adults and pediatric
patients (2 to 16 years of age). This is a randomized, double-blind, parallel-group,
placebo-controlled study to evaluate the effectiveness and safety of topiramate as an add-on
therapy in patients with Primary Generalized Tonic-Clonic (PGTC) seizures. The study is in
two phases: baseline (8 weeks) and double-blind treatment (20 weeks). Patients are given
diaries to record information about their seizures during the phases of the study. During
the baseline phase, the patient continues to receive a constant dosage of one or two
antiepileptic drugs they have been taking. In the double-blind phase, patients are randomly
assigned to either topiramate or placebo. The double-blind phase is divided into two periods:
titration, in which the topiramate dose is gradually increased (8 weeks) (patient's
antiepileptic medication continues; this dose remains the same) and stabilization (12 weeks).
The dose of both topiramate and the patient's antiepileptic drug remain constant during the
stabilization period. Based on the investigator's judgment, patients completing the
double-blind treatment could enter a long-term extension phase of the study to continue
treatment. The primary assessment of effectiveness is the percent reduction in primary
generalized tonic-clonic seizure rates from baseline to the double-blind phase. Safety
assessments include the frequency of adverse events during the study, results of clinical
laboratory tests (hematology, biochemistry, and urinalysis), measurements of vital signs and
body weight, physical examination and electrocardiogram (ECG) findings, plasma levels of
topiramate and other study antiepileptic drugs, and neurological examinations. The study
hypothesis is that topiramate as an add-on is superior to placebo in reducing the seizure
rate from baseline to the double-blind phase of the study.
Topiramate (25 mg or 100 mg tablets) or placebo, taken by mouth, starting at a dose of 25 or
50mg/day, gradually increasing to a maximum daily dose of 175 mg to 400 mg (based on body
weight) or to a maximum tolerated dose (whichever dose is less). Maximum dosage continues for
Minimum age: 4 Years.
Maximum age: N/A.
- Body weight >25 kilograms (55 pounds)
- Diagnosis of primary generalized epilepsy
- Must have primary generalized tonic-clonic (PGTC) seizures treated with 1 or 2
- Must have three PGTC seizures during baseline period, with at least 1 during each
28-day period of baseline
- Females must not have had their first menstrual period or be postmenopausal, or are
physically incapable of child bearing, or if of child bearing potential, sexually
abstinent, or using adequate birth control measures, and have a negative pregnancy
test before study entry
- Patients who do not have epilepsy, such as those with a treatable cause of seizure
(for example, active infection or cancer)
- Patients with progressive disorders (for example, active infection, cancer or
- Patients diagnosed with Lennox-Gastaut syndrome
- History of seizures occurring in only cluster patterns (numerous seizures occurring
over a short period of time [<30 minutes])
- Documented history (previous 3 months) of generalized tonic-clonic status epilepticus
(status epilepticus is a prolonged seizure or seizures repeated frequently over 20 to
30 minutes so that recovery between episodes does not occur) while receiving
appropriate antiepileptic medication
Locations and Contacts
A study of the efficacy and safety of topiramate in patients with primary generalized tonic-clonic seizures
Starting date: December 1994
Ending date: December 1996
Last updated: May 11, 2007