AT AES 2016
HOUSTON (FRONTLINE MEDICAL NEWS) – Pooled data for a recently approved antiepileptic drug show good safety and tolerability when it’s administered intravenously.
Intravenous brivaracetam, when given to 104 patients with epilepsy and 49 healthy volunteers, was generally well tolerated, though about one in three patients experienced somnolence, and one in four had some dizziness and fatigue. This adverse event profile was similar to that seen in clinical trials of the oral formulation of brivaracetam, Pavel Klein, MD, said in an interview during a poster session at the annual meeting of the American Epilepsy Society, though euphoria and dysgeusia were more common among healthy volunteers receiving intravenous brivaracetam.
“Looking at the side effects, the medication was well tolerated. … The main side effects were dizziness, somnolence, and fatigue, and by and large, these were mild or moderate. Nobody discontinued the medication because of side effects in the patient population,” said Dr. Klein, director of the Mid-Atlantic Epilepsy and Sleep Center, Bethesda, Md.
The poster presentation pooled safety and tolerability data from three separate studies: a 25- to 150-mg dose-escalation, three-way crossover study of 24 healthy volunteers, a bioequivalence study involving 25 healthy volunteers who received a 100-mg dose of brivaracetam orally or as an intravenous bolus, and a phase III, four-arm parallel group study of 104 patients with focal or generalized seizures. In this last study, patients received either oral brivaracetam or a placebo for a run-in period of 7 days, followed by 4.5 days of intravenous brivaracetam; patients were on one to two other antiepileptic drugs during the study period.
In the overall group of participants in all three studies, somnolence was seen in 30.1% of participants, dizziness in 15.7%, and fatigue in 15.0%. However, when compared with patients with epilepsy, healthy volunteers given brivaracetam 100 mg IV had a higher overall adverse event incidence, and notably more dizziness (35.5% versus 7.7%) and fatigue (29.0% versus 4.8%). One epilepsy patient in the phase III study (1/104; 1%) discontinued the study because of an adverse event.
Also, healthy volunteers, rather than patients, were more likely to experience euphoric mood and dysgeusia with intravenous as compared with oral brivaracetam.
The reason for these differences between the epilepsy and nonepilepsy groups is not known; however, wrote Dr. Klein and his coauthors, part of the difference might be “due to heterogeneous medical histories and concomitant medication use.”
Otherwise, intravenous brivaracetam administration was associated with about the same number of adverse events as when the drug was taken orally.
Brivaracetam, approved earlier in 2016, like levetiracetam, is a ligand for the synaptic vesicle protein 2a, the mechanism that’s thought to be responsible for the antiepileptic effect of this drug class. However, brivaracetam has a 15- to 30-fold higher affinity for its target than its older cousin. It’s approved in the United States as adjunctive therapy for focal seizures in individuals aged 16 and older with epilepsy. When administered intravenously, brivaracetam may be given as a bolus or an infusion over 15 minutes.
Dr. Klein serves on the speakers bureau of UCB Pharma, and has received research support from the company, which funded the study and assisted with poster preparation.
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