Abstracts

Rationale: Depression and anxiety are common psychiatric comorbidities in patients with epilepsy. The objective of this analysis was to explore the relationship between anxiety and depression symptoms and baseline seizure rate and response to adjunctive pregabalin therapy using data from 2 clinical studies of flexible-dose pregabalin as adjunctive treatment for partial-onset epilepsy. Methods: Study 1079, a randomized, placebo-controlled trial, and study 1088, an uncontrolled, open-label trial, evaluated the safety and efficacy of flexible-dose pregabalin used adjunctively in patients with partial seizures. Patients were included in these studies who had a diagnosis of epilepsy with partial seizures and whose seizures were not adequately controlled by 1-3 concurrently administered antiepileptic drugs. Patients were required to have experienced ?2 (study 1088) or ?4 (study 1079) seizures during the baseline phase. Hospital Depression and Anxiety Scale (HADS-D and HADS-A), RRatio, and 50% Responder rates were assessments used in both studies. The 28-day seizure frequency was assessed from patient-reported seizure activity recorded daily in diaries during the screening (study 1079, 6 weeks; study 1088, 8 weeks) and the 12-week treatment periods. The relationships between 28-day baseline seizure rate and HADS-A and HADS-D scores were evaluated by Pearson correlation analysis. The relationships between severity of anxiety and depression symptoms (high: HADS score >9; low: HADS score ?9) at baseline and response to pregabalin assessed using RRatio and 50% Responder rates were evaluated descriptively. Results: A total of 178 patients were enrolled in study 1079 (pregabalin, n=119; placebo n=59; 48.3% male; 100% Asian) and 98 patients in study 1088 (50% male; 100% white). The mean (standard deviation [SD]) baseline 28-day seizure frequency was 5.8 (6.7) in study 1088 and 13.2 (14.5), and 13.2 (19.2) for the pregabalin and placebo groups in study 1079, respectively. The mean (SD) HADS-A/HADS-D scores at baseline were 7.4 (5.3)/5.3 (3.6) for study 1088 and 8.3 (3.9)/9.3 (3.6) and 8.4 (3.7)/9.0 (3.8) for the pregabalin and placebo groups in study 1079, respectively. No correlation was observed between baseline HADS-A or HADS-D scores and 28-day seizure rate at baseline in either study (P?0.1). In both studies, improvements with pregabalin in both 50% responder rates and RRatios were observed in patients with either less severe (HADS score ?9) or more severe (HADS score >9) baseline mood symptoms (Table 1). Conclusions: In this post hoc analysis, no relationship between baseline seizure frequency and anxiety and depression symptoms was found in 2 studies of flexible-dose pregabalin used adjunctively in patients with partial-onset seizures. Furthermore, improvements in seizure reduction measures with pregabalin were observed regardless of the severity of baseline depression and anxiety symptoms. Funded by Pfizer.