Effects of Concomitant Lamotrigine or Valproate Therapy on Clobazam for Lennox-Gastaut Syndrome: Subanalyses of the CONTAIN Trial (P06.120)

Clobazam: A Safe, Efficacious, and Newly Rediscovered Therapeutic for Epilepsy

Clobazam is an oral 1,5-benzodiazepine used worldwide for the treatment of many types of epilepsies, although it is currently only approved for Lennox-Gastaut syndrome in the USA. This anticonvulsant and anxiolytic therapeutic has repeatedly demonstrated great efficacy and a high safety profile in refractory epilepsy as well as in a few monotherapy trials in both children and adults. Clobazam allosterically activates the GABAA receptor, and it binds less to subunits that mediate sedative effects than other benzodiazepines. It acts quickly, maintaining a therapeutic effect for a long duration due to its active metabolite, N-desmethylclobazam. Dosage is between 5 mg and 40 mg a day, depending on patient weight, efficacy, and tolerability. Efficacy tolerance has not been a problem in the best studies. Clobazam has provided many benefits to epileptic patients. It should be used by clinicians early as an adjuvant therapy in the treatment of refractory epilepsy and even considered as monotherapy in a broad spectrum of epilepsy syndromes.

Clobazam : in patients with Lennox-Gastaut syndrome

Clobazam, as with other benzodiazepines, has a long history of use in the treatment of epilepsy. More recently, it was approved in the USA as adjunctive therapy for the treatment of seizures associated with Lennox-Gastaut syndrome in patients aged ≥2 years. In the pivotal, placebo-controlled CONTAIN trial in paediatric and adult patients with Lennox-Gastaut syndrome (n = 217 evaluable), adjunctive therapy with clobazam 5-40 mg/day for 12 weeks significantly reduced mean weekly drop seizure rates from baseline compared with adjunctive placebo (primary endpoint), with a significant dosage-dependent improvement in these rates. Results from a dosage-ranging, double-blind, multi-centre, phase II trial add further support for the efficacy of clobazam in paediatric and adult patients with Lennox-Gastaut syndrome (n = 61 evaluable). Improvements in mean weekly drop seizure rates with adjunctive clobazam treatment in these short-term trials was maintained in an ongoing, open-label extension study, with a 91.6 % reduction in mean weekly drop seizure rates from baseline (at randomization in the initial trials) to 24 months in the overall population. Treatment with adjunctive clobazam was generally well tolerated in these clinical trials and after at least 2 years of treatment in an open-label extension study. Most adverse events were mild or moderate and similar to those typically observed with other benzodiazepines.