Brivaracetam for the treatment of epilepsy in adults

Comparison of the safety of brivaracetam at various doses among patients with epilepsy: A network meta-analysis of randomized controlled trials

The present study aimed to compare the safety of brivaracetam (BRV) at various doses among patients with epilepsy through a network meta-analysis. Randomized controlled trials (RCTs) were retrieved from different databases, which were then pooled for a network analysis for calculating the odds ratios (ORs), together with the corresponding 95% confidence intervals (CIs) and surface under the cumulative ranking curve (SUCRA). A total of 9 RCTs were included in the final analysis. Compared with placebo, BRV at a dose of 50 mg daily led to a markedly increased risk of nervous system disorders (OR, 0.62; 95% CI, 0.43-0.90; P=0.01) and evidently increased the risk of psychiatric disorders (OR, 0.16; 95% CI, 0.04-0.64; P=0.022). However, BRV treatment was not associated with a statistically significant change in the prevalence of infectious diseases. SUCRA analysis suggested that treatment with BRV at 50 mg/day posed the highest risk of nervous system disorders and psychiatric disorders compared with placebo or other doses of BRV. In conclusion, BRV treatment at a dose of 50 mg/day may increase the risk of nervous system diseases and psychosis disorders compared with the placebo group. However, more high-quality clinical studies are warranted to validate these results.

Brivaracetam, a selective high-affinity synaptic vesicle protein 2A (SV2A) ligand with preclinical evidence of high brain permeability and fast onset of action

OBJECTIVE

Rapid distribution to the brain is a prerequisite for antiepileptic drugs used for treatment of acute seizures. The preclinical studies described here investigated the high-affinity synaptic vesicle glycoprotein 2A (SV2A) antiepileptic drug brivara-cetam (BRV) for its rate of brain penetration and its onset of action. BRV was compared with levetiracetam (LEV).

METHODS

In vitro permeation studies were performed using Caco-2 cells. Plasma and brain levels were measured over time after single oral dosing to audiogenic mice and were correlated with anticonvulsant activity. Tissue distribution was investigated after single dosing to rat (BRV and LEV) and dog (LEV only). Positron emission tomography (PET) displacement studies were performed in rhesus monkeys using the SV2A PET tracer [11C]UCB-J. The time course of PET tracer displacement was measured following single intravenous (IV) dosing with LEV or BRV. Rodent distribution data and physiologically based pharmacokinetic (PBPK) modeling were used to compute blood-brain barrier permeability (permeability surface area product, PS) values and then predict brain kinetics in man.

RESULTS

In rodents, BRV consistently showed a faster entry into the brain than LEV; this correlated with a faster onset of action against seizures in audiogenic susceptible mice. The higher permeability of BRV was also demonstrated in human cells in vitro. PBPK modeling predicted that, following IV dosing to human subjects, BRV might distribute to the brain within a few minutes compared with approximately 1 h for LEV (PS of 0.315 and 0.015 ml/min/g for BRV and LEV, respectively). These data were supported by a nonhuman primate PET study showing faster SV2A occupancy by BRV compared with LEV.

SIGNIFICANCE

These preclinical data demonstrate that BRV has rapid brain entry and fast brain SV2A occupancy, consistent with the fast onset of action in the audiogenic seizure mice assay. The potential benefit of BRV for treatment of acute seizures remains to be confirmed in clinical studies.

The efficacy and safety of brivaracetam at different doses for partial-onset epilepsy: a meta-analysis of placebo-controlled studies

OBJECTIVE

This meta-analysis systematically assessed the efficacy and safety of different doses of brivaracetam (BRV) compared with placebo as adjunctive therapy for adults with partial-onset epilepsy.

METHODS

Electronic and clinical trials databases were searched for randomized controlled trials of BRV published up to May 2015. We assessed the risk of bias of the included studies using the Cochrane Risk of Bias tool. The outcomes of interest included 50% responder rates, seizure freedom, the incidence of withdrawal and treatment-emergent adverse events (TEAEs).

RESULTS

Five trials met the inclusion criteria. Compared with placebo, 20, 50, 100 and 150 mg/day BRV was associated with significantly higher 50% responder rates. In addition, the effect of 50 mg BRV on seizure freedom was significantly different than that of placebo. Both fatigue and nasopharyngitis were significantly associated with 20 mg BRV, whereas fatigue and irritability were associated with 50 mg BRV. Somnolence was associated with 150 mg BRV. No significant differences were observed for the other common TEAEs.

CONCLUSION

The use of BRV at doses > 5 mg/day resulted in statistically significant reduction in seizure frequency in respect to the 50% responder rate. BRV was reasonably tolerated by patients. These findings warrant confirmation in future studies.

USL255 extended-release topiramate for the treatment of epilepsy

USL255 is a once-daily, extended-release formulation of the well-established antiepileptic drug topiramate that was recently approved by the US FDA. As a capsule formulation, USL255 can be swallowed intact or opened and sprinkled onto soft food for patients with swallowing difficulties, including children (≥2 years old) and older patients. USL255 has been evaluated in seven key Phase I and III studies. Compared with immediate-release topiramate taken twice daily, once-daily USL255 provides equivalent topiramate exposure with a 26% reduction in plasma fluctuations. A multinational, Phase III, randomized, double-blind, placebo-controlled clinical trial in patients with refractory partial-onset seizures (PREVAIL) demonstrated that USL255 (200 mg/day) significantly improved seizure control and clinical outcomes versus placebo. USL255 is generally safe and well-tolerated, with a low incidence of neuropsychiatric and neurocognitive adverse events. These data suggest that USL255 may provide a useful treatment option for seizure control with convenient once-daily dosing.