perampanel and rufinamide

There are currently five compounds (clobazam, felbamate, lamotrigine, topiramate, rufinamide) available for prescription with a demonstrated efficacy on drop seizures for Lennox-Gastaut syndrome (LGS). There are also currently new and under-investigation compounds. This paper gives an overview on these novel developments for LGS based on the lecture given at the French Chapter meeting of the International League Against Epilepsy (ILAE) held in Paris in October 2019. Five compounds were discussed. Epidiolex (cannabidiol) has been approved recently based on positive randomized control trials in LGS patients. Four drugs are under investigation according to a search on the 'clinicaltrials.gov' database. Perampanel and fenfluramine are both being studied in ongoing phase 3 studies. Two compounds are in an earlier stage of development with ongoing phase 1 and 2 studies: carisbamate and OV953. We summarized the publicly available data. Based on these drug development programs, we can expect that new compounds will become available for LGS in the next years, possibly resulting in new treatment paradigms.

Topics: Anticonvulsants; Cannabidiol; Drug Development; Drugs, Investigational; Fenfluramine; Humans; Lennox Gastaut Syndrome; Nitriles; Pyridones; Therapies, Investigational; Triazoles

Antiepileptic drugs (AEDs) have been used to control epilepsy. More than 17 new AEDs, including gabapentin (GPN), lacosamide (LCM), perampanel (PER), pregabalin (PRG), rufinamide (RFM), and vigabatrin (VGB) have been approved and marketed since 1989. Accurate measurement of serum concentration of the antiepileptic drugs is crucial to achieve optimal efficacy and avoid adverse events. We describe an accurate and precise liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the simultaneous quantification of GPN, LCM, PER, PRG, RFM, and VGB in serum. The method requires a small volume of sample (10 μL) and has a total chromatographic run time of 4 min for simultaneous measurement of these drugs. The method showed good accuracy with a bias of -0.2-5%. The intra- and inter-day imprecision were less than 5.0% for all the analytes. The linear assay ranges were 0.3-26 μg/mL for GPN, 0.15-24 μg/mL for LCM, 7.4-1881 ng/mL for PER, 0.03-13 μg/mL for PRG, 0.78-90 μg/mL for RFM, and 0.3-43 μg/mL for VGB.

Topics: Anticonvulsants; Chromatography, Liquid; Gabapentin; Lacosamide; Pregabalin; Tandem Mass Spectrometry; Vigabatrin

New-generation antiepileptic drugs as perampanel, rufinamide and stiripentol emerged as alternatives in chronic epilepsy polytherapy. Hence, their metabolic stability and potential involvement in relevant drug-drug interactions (DDI) are of great clinical interest, being HepaRG cells herein used as an in vitro human model. To characterize their metabolic stability profiles, HepaRG cells were incubated with perampanel (1 μM), rufinamide (100 μM) or stiripentol (5 μM) for 12-h. HepaRG cells, pretreated with known CYP450 isoenzymes inducers (rifampicin, phenytoin, phenobarbital, omeprazole and carbamazepine), were also incubated with perampanel, rufinamide or stiripentol to assess possible DDI mediated by CYP450 induction. Results suggest a considerable decrease in perampanel and stiripentol concentrations over 12-h; contrary, rufinamide concentrations did not variated. Cells pretreatment with all inducers significantly decreased stiripentol concentrations (between 20.3% and 31.9%), suggesting a considerable potential for DDI. Rufinamide concentrations only decreased when preincubated with rifampicin and with the highest tested concentrations of the remaining inducers. Perampanel levels decreased with rifampicin, carbamazepine and phenobarbital, supporting the involvement of CYP3A4-mediated metabolism. Besides relevant information concerning the metabolic stability profile and potential DDIs of the new antiepileptics here studied, it was also reinforced the HepaRG cells suitability as a reliable in vitro model to foresee in vivo metabolism in humans.

Topics: Anticonvulsants; Carbamazepine; Cytochrome P-450 Enzyme Inducers; Dioxolanes; Drug Interactions; Humans; Nitriles; Phenobarbital; Pyridones; Rifampin; Triazoles