Abstracts

Rationale: The purpose of this study was to look at the efficacy and safety of add-on pregabalin when used in combination with levetiracetam and other antiepileptic drugs (AEDs), to treat patients with partial seizures in the pregabalin epilepsy double-blind randomized trial database. Methods: Data were pooled from 2 randomized, double-blind, placebo-controlled trials of add-on pregabalin treatment in patients with partial seizures (dosages ranged from 150 mg/d to 600 mg/d, fixed- or flexible-dosage regimens). Patients were males or females, ages 18 years or older, with a diagnosis of epilepsy with partial seizures. The efficacy variables in this analysis were percent change in 28-day seizure rate from baseline, responder rates, and seizure freedom rates for all pregabalin treatment groups combined versus placebo. All partial seizures were considered. Treatment-emergent adverse events (AEs) were also assessed. Results: 138 intent-to-treat (ITT) patients in the pregabalin trials were receiving levetiracetam at the time of entering the studies. Of the 138 ITT patients, 31 patients received pregabalin 300 mg/d, 35 received pregabalin 600 mg/d, 25 received pregabalin flexible-dosage, and 47 received placebo. The mean age was 39.3 years (range: 19.0 to 69.0 years), and the median baseline seizure rate was 9.4. For percent change from baseline in seizure frequency, the Hodges-Lehman estimate for treatment difference between pregabalin and placebo was -24.5%, favoring pregabalin (95% confidence interval: -40.7 to -8.5). The proportion of 50% responders in all pregabalin groups combined (37.4%) was significantly higher when compared with the placebo group (14.9%; P=.0053). Similarly, the proportion of 75% responders in the pregabalin group (13.2%) favored pregabalin when compared with the placebo group (0%, P=.0002). There was no significant difference in seizure freedom rates during the last 28-day period between the pregabalin group (7.7%) and the placebo group (6.4%, P=1.00). The most common treatment-emergent AEs with pregabalin were somnolence and dizziness. Conclusions: Pregabalin, when added on to other AED combinations including levetiracetam, is safe and effective for treatment of refractory partial seizures. Study funded by Pfizer Inc.