The AMPA antagonist perampanel is proving to be an effective and well tolerated adjunctive treatment for people with drug-resistant epilepsy, Australian real world results suggest.

In a retrospective observational study of 387 patients managed in nine Australian epilepsy centres, late add-on treatment with perampanel resulted in 21.7% responder rates (at least 50% reduction in seizure frequency) and 9.0% seizure freedom after 12 months maintenance.

The one year retention rate on treatment was 40%, and it was assumed that missing cases were treatment failures.

Perampanel treatment was also generally well tolerated, with the main side effects being neuropsychiatric effects such as irritability (19%), dizziness (14%) and sleepiness (6%).

The study authors led by Dr Parveen Sagar of St Vincent’s Hospital Melbourne, said the responder rates were lower than reported in some other studies of perampanel but were nevertheless a favourable reflection of real world long term use. They were particularly good for  a group of patients with severe drug resistant epilepsy who had trialled an average six other antiepileptic drugs and of whom 72% had never experienced six months of seizure freedom prior to perampanel.

Factors associated with better retention included male sex (adjusted OR [aOR] 2.06), lower number of prior AEDs (aOR 0.84) and no previous seizure-free period of at least 6-month duration (aOR 2.04).

The researchers also looked at whether combinations of particular antiepileptic drug modes of action would have an influence on outcomes, but the only significant one was perampanel combined with a GABA receptor being associated with a lower responder rate at 12 months.

The findings are published in Epilepsy and Behavior.

Disclosures: The study was funded by Eisei, which developed perampanel