Abstracts

Rationale: The purpose of this study was to evaluate the efficacy and safety of pregabalin as add-on treatment for partial seizures in patients over the age of 50. Methods: Data were pooled from 6 randomized, double-blind, placebo-controlled trials of add-on pregabalin treatment in patients with partial seizures (dosages: 150-600 mg/d, flexible- or fixed-dosage regimens, BID or TID). Patients were males or females, ages 50 years or older, who had a diagnosis of refractory partial epilepsy. The percent change in seizure frequency from baseline, responder rates, and seizure-freedom rates were evaluated for all pregabalin treatment groups combined vs placebo (all partial seizures considered). Treatment-emergent adverse events (AEs) were also evaluated. Results: 335 intent-to-treat patients were 50 years old or older (n=31: pregabalin 150 mg/d, 46: pregabalin 300 mg/d, 101: pregabalin 600 mg/d, 46: pregabalin flexible-dosage, 111: placebo). The mean age (56 years; range: 50-82 years) and median baseline seizure rate (8) were similar across treatment groups. For percent change from baseline to endpoint in seizure frequency, the Hodges-Lehman estimate for treatment difference between pregabalin and placebo (-46.3%) favored pregabalin (95% confidence intervaI: -56.9 to -35). The proportion of 50% responders (patients who achieved ≥50% reduction in seizure frequency) in the pregabalin treatment group (54.9%) was significantly larger vs placebo (15.3%, P<.0001). Similarly, the proportion of 75% responders in the pregabalin group (30.8%) was significantly larger when compared with placebo (2.7%, P<.0001). Additionally, more pregabalin patients (16.9%) achieved seizure freedom during the last 28-day treatment period compared with placebo (4.7%, P=.0018). The most common treatment-emergent AEs for pregabalin were dizziness (35.3%), ataxia (21.9%), somnolence (21.0%), asthenia (15.2%), and weight gain (13.8%). For placebo, the most common treatment-emergent AEs were asthenia (16.2%), dizziness (15.3%), headache (13.5%), somnolence (11.7%), and nausea (6.3%). Conclusions: Add-on pregabalin is an effective and well-tolerated treatment for partial seizures in patients over the age of 50. Study funded by Pfizer Inc.