Efficacy and tolerability of adjunctive brivaracetam in adults with uncontrolled partial-onset seizures: a phase IIb, randomized, controlled trial.

PURPOSE: To evaluate the efficacy and tolerability of adjunctive brivaracetam (BRV), a novel high-affinity synaptic vesicle protein 2A ligand that also displays inhibitory activity at neuronal voltage-dependent sodium channels, in adult epilepsy patients with uncontrolled partial-onset seizures. METHODS: A phase IIb, double-blind, randomized, placebo-controlled, parallel-group, dose-ranging study (N01114; NCT00175929) was conducted in patients aged 16-65 years. To be included in the study, patients were required to have experienced four or more partial-onset seizures during a 4-week prospective baseline, despite treatment with 1-2 concomitant antiepileptic drugs. Patients were randomized in a ratio of 1:1:1 to receive BRV 50 mg/day (BRV50), 150 mg/day (BRV150), or placebo. A 3-week up-titration period was followed by a 7-week maintenance period (total treatment period of 10 weeks). KEY FINDINGS: A total of 157 patients were randomized (intent-to-treat [ITT] population; BRV50 n = 53, BRV150 n = 52, placebo n = 52) and overall 148 (94.3%) completed the study. The percent reduction in baseline-adjusted partial-onset seizure frequency/week over placebo during the 7-week maintenance period (primary efficacy outcome) did not reach statistical significance (14.7% for BRV50 [p = 0.093] and 13.6% for BRV150 [p = 0.124]). However, during the entire 10-week treatment period a statistically significant difference was observed for both BRV groups (17.7% for BRV50 [p = 0.026] and 16.3% for BRV150 [p = 0.043]). The median percent reduction from baseline in partial-onset seizure frequency/week during the maintenance period was 38.2% for BRV50 (p = 0.017) and 30.0% for BRV150 (p = 0.113) versus 18.9% in the placebo group. During the treatment period, this was 34.9% for BRV50 (p = 0.004) and 28.3% for BRV150 (p = 0.070) compared with 16.3% for placebo. Fifty percent responder rates during the maintenance period were 23.1% for placebo compared with 39.6% for BRV50 (odds ratio [OR] 2.17, p = 0.077) and 33.3% for BRV150 (OR 1.66, p = 0.261). During the treatment period, 50% responder rates were 17.3% for placebo compared with 35.8% for BRV50 (OR 2.69, p = 0.038) and 30.8% for BRV150 (OR 2.15, p = 0.114). Nine patients were free from partial-onset seizures during the 10-week treatment period (five patients [9.4%] in the BRV50 group and three [5.8%] in the BRV150 group compared with one patient [1.9%] in the placebo group). Treatment-emergent adverse events (TEAEs) reported during the treatment period were mostly mild-to-moderate with similar incidence across treatment groups (BRV50 36/53, 67.9%; BRV150 35/52, 67.3%; placebo 37/52, 71.2%). The most frequently reported TEAEs in BRV groups were headache, fatigue, nasopharyngitis, nausea, somnolence, and dizziness, although nausea had a higher incidence in the placebo group. SIGNIFICANCE: In this double-blind, placebo-controlled, phase IIb study of adjunctive BRV (50 and 150 mg/day) in adults with uncontrolled partial-onset seizures, the primary efficacy analysis did not reach statistical significance; however, statistically significant differences compared with placebo were observed on several secondary efficacy outcomes. BRV was well tolerated.

Anxiolytic effects of the novel anti-epileptic drug levetiracetam in the elevated plus-maze test in the rat.

There is clinical evidence of anxiolytic action of several anti-epileptic drugs. We evaluated the effects of levetiracetam (Keppra), a new generation anti-epileptic drug, in the plus-maze animal test for anxiolytic activity. Levetiracetam at 17 and 54 mg/kg intraperitoneally (i.p.) was without effect when tested in naive rats. A modified version of the test was subsequently used in which open-arm exploration was decreased by exposure of the rats to a four-open-arm maze 24 h prior to drug treatment and testing. Under these conditions of enhanced anxiety, levetiracetam, 5.4 to 54 mg/kg, dose-dependently increased open-arm exploration. Chlordiazepoxide 5 mg/kg had similar effects although buspirone 0.1 to 1.0 mg/kg was inactive. The results with levetiracetam substantiate similar findings of its anxiolytic actions against chlordiazepoxide withdrawal-induced anxiety in mice and in a modified Vogel test in rats and support a potential clinical use of this drug in anxiety states.

Anxiolytic profile of the antiepileptic drug levetiracetam in the Vogel conflict test in the rat.

The novel antiepileptic drug levetiracetam has been shown to reverse anxiogenic effects of benzodiazepine withdrawal in mice tested in an elevated plus-maze without altering the behaviour of normal mice in this model. This could suggest that the effect of levetiracetam is dependent upon the level of stress/anxiety of the animals. Levetiracetam was therefore further examined in another widely used animal model of anxiety, the Vogel conflict test. In the first experiment, water-deprived rats were submitted to a free drinking period (habituation) in a chamber equipped with a bottle of water. Twenty-four hours later, animals were returned to the same chamber but the licks to the water bottle were then punished with a foot shock (0.5 mA, 90 ms). In the second experiment, the procedure was modified by administering a foot shock at the end of the habituation period in order to induce a state of stress/anxiety (conditioned fear/ anticipatory anxiety) for subsequent testing. Levetiracetam (17 and 54 mg/kg) and chlordiazepoxide (5 mg/kg) were administered via the intraperitoneal route. The results indicated that in the first experiment only chlordiazepoxide showed a statistically significant anxiolytic effect. In contrast, in the second experiment, where the shock was given at the end of the habituation period, levetiracetam (54 mg/kg) revealed significant anxiolytic activity similar to chlordiazepoxide. This suggests that levetiracetam may have potential anxiolytic effects and may provide therapeutic benefits to individual with anxiety spectrum disorders.

Levetiracetam intravenous infusion as an alternative to oral dosing in patients with partial-onset seizures.

PURPOSE: This multicenter, open-label study evaluated the short-term tolerability of intravenously (IV)-infused levetiracetam (LEV; 500-1,500 mg/100 ml, 15 min, b.i.d.) as a substitute for the same oral dose. METHODS: The study consisted of screening, 4-day IV LEV and 1-7 days of follow-up, and was conducted in 25 adults with partial-onset seizures receiving adjunctive oral LEV. RESULTS: During the 4-day IV LEV, 11 (44%) subjects experienced at least one treatment-emergent adverse event (TEAE), with headache and fatigue being the most frequently reported. Five (20%) subjects experienced TEAEs considered to be related to the study drug. The tolerability profile was consistent with that of oral LEV, with all events judged mild or moderate in severity, no discontinuations, and no serious AEs or deaths reported. No AE related to seizure worsening was reported during IV LEV or brief follow-up. CONCLUSIONS: LEV IV appears to be a well-tolerated, practical alternative in patients with partial-onset seizures temporarily unable to take the drug orally.