VANCOUVER, BC—Adjunctive therapy with vigabatrin, tiagabine, or pregabalin for refractory complex partial-onset seizures (POS) is associated with superior reductions in seizure frequency compared to other antiepileptic drugs (AEDs), according to authors of a systematic literature review presented at the 68th AAN Annual Meeting.

“Patients receiving pregabalin, tiagabine, and vigabatrin had the highest pooled odds versus placebo of experiencing a ≥50% reduction in seizures,” wrote lead author Jeremy Slater, MD, University of Texas Health Science Center, Houston, TX, and coauthors, in a poster presentation.

“Patients receiving ezogabine, levetiracetam, and vigabatrin had the highest pooled odds versus placebo of achieving seizure freedom,” they also reported.

Placebo-controlled clinical trials have helped to quantify AED efficacies for POS, but scant heat-to-head comparison trials have been reported. “It is therefore of interest to compare the efficacy of all current AEDs approved for adjunctive treatment of refractory POS, using a pragmatic study design that incorporates the pivotal trials that were used to obtain U.S. Food and Drug Administration (FDA) drug approval,” the poster coauthors explained.

They therefore compared FDA-approved AEDs’ relative efficacies for refractory POS in a systematic review and meta-analysis of data pooled from 30 pivotal trials, representing studies of 12 AEDs, the researchers reported.

“Compared with placebo, the pooled odds of patients experiencing a ≥50% reduction in seizure frequency increased 6.23 with vigabatrin (3000mg/day), 8.08 with pregabalin (600mg/day), and 8.82 with tiagabine (56mg/day),” they reported.

The pooled odds for seizure freedom “were at least 7 times greater for patients receiving levetiracetam (3000mg/day), vigabatrin (3000mg/day), and ezogabine (1200mg/day) than placebo,” they added.

Adverse events-associated treatment discontinuation rates were higher than placebo for all AEDs other than pregabalin, they noted. However, the data analyzed did not include long-term adverse effects, they cautioned. “This meta-analysis was limited to studies that reported the 50% responder rate, seizure freedom, or discontinuation rate due to AEs.”

Dr. Slater disclosed receiving speaking fees from UCB Pharma and Lundbeck LLC, which funded the study.