Pregabalin (Page 9 of 13)

14.3 Adjunctive Therapy for Partial-Onset Seizures in Patients 17 Years of Age and Older

Adjunctive Therapy for Partial-Onset Seizures in Adult Patients
The efficacy of pregabalin as adjunctive therapy for partial-onset seizures in adult patients was established in three 12-week, randomized, double-blind, placebo-controlled, multicenter studies. Patients were enrolled who had partial-onset seizures with or without secondary generalization and were not adequately controlled with 1 to 3 concomitant antiepileptic drugs (AEDs). Patients taking gabapentin were required to discontinue gabapentin treatment 1 week prior to entering baseline. During an 8-week baseline period, patients had to experience at least 6 partial-onset seizures with no seizure-free period exceeding 4 weeks. The mean duration of epilepsy was 25 years in these 3 studies and the mean and median baseline seizure frequencies were 22.5 and 10 seizures per month, respectively. Approximately half of the patients were taking 2 concurrent AEDs at baseline. Among the pregabalin-treated patients, 80% completed the double-blind phase of the studies. Table 11 shows median baseline seizure rates and median percent reduction in seizure frequency by dose.

Table 11. Seizure Response in Controlled, Adjunctive Epilepsy Studies in Adults

In the first study (E1), there was evidence of a dose-response relationship for total daily doses of pregabalin between 150 and 600 mg/day; a dose of 50 mg/day was not effective. In the first study (E1), each daily dose was divided into two equal doses (twice a day dosing). In the second study (E2), each daily dose was divided into three equal doses (three times a day dosing). In the third study (E3), the same total daily dose was divided into two equal doses for one group (twice a day dosing) and three equal doses for another group (three times a day dosing). While the three times a day dosing group in Study E3 performed numerically better than the twice a day dosing group, this difference was small and not statistically significant.
A secondary outcome measure included the responder rate (proportion of patients with greater than or equal to 50% reduction from baseline in partial seizure frequency). The following figure displays responder rate by dose for two of the studies.Figure 6: Responder rate by Adjunctive Epilepsy Study

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Figure 7: Seizure Reduction by Dose (All Partial-Onset Seizures) for Studies E1, E2, and E3

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Subset evaluations of the antiseizure efficacy of pregabalin showed no clinically important differences as a function of age, gender, or race.
Pediatric use information is approved for Pfizer’s LYRICA (pregabalin) Capsules and Oral Solution products. However, due to Pfizer’s marketing exclusivity rights, this drug product is not labeled with that pediatric information.