rwj-333369 and Epilepsy

Epilepsy is a common neurological condition, affecting over 70 million individuals worldwide.. The present paper reviews current and future (under preclinical and clinical development) pharmacotherapy options for the treatment of drug-resistant focal and generalized epilepsies.. Current pharmacotherapy options for drug-resistant epilepsy include perampanel, brivaracetam and the newly approved cenobamate for focal epilepsies; cannabidiol (Epidiolex) for Lennox-Gastaut Syndrome (LGS), Dravet and Tuberous Sclerosis Complex (TSC); fenfluramine for Dravet syndrome and ganaxolone for seizures in Cyclin-dependent kinase-like 5 (CDKL5) deficiency disorder. Many compounds are under clinical development and may hold promise for future pharmacotherapies. For adult focal epilepsies, padsevonil and carisbamate are at a more advanced Phase III stage of clinical development followed by compounds at Phase II like selurampanel, XEN1101 and JNJ-40411813. For specific epilepsy syndromes, XEN 496 is under Phase III development for potassium voltage-gated channel subfamily Q member 2 developmental and epileptic encephalopathy (KCNQ2-DEE), carisbamate is under Phase III development for LGS and Ganaxolone under Phase III development for TSC. Finally, in preclinical models several molecular targets including inhibition of glycolysis, neuroinflammation and sodium channel inhibition have been identified in animal models although further data in animal and later human studies are needed.

Topics: Adult; Animals; Anticonvulsants; Cannabidiol; Epilepsies, Partial; Epilepsy; Humans; Lennox Gastaut Syndrome; Spasms, Infantile; Tuberous Sclerosis

Carisbamate (RWJ-333369) is a novel neuromodulator, initially developed by SK Biopharmaceuticals (Fairlawn, NJ), under development by Johnson & Johnson Pharmaceutical Research and Development (La Jolla, CA). Carisbamate displays high potency in a broad range of rodent seizure models at doses well below those that produce CNS toxicity. Its mechanism of action has not been elucidated. Acute and chronic nonclinical toxicological studies have not revealed any significant abnormalities other than dose-related CNS toxicity. It is extensively metabolized, chiefly through glucuronidation and oxidation of the aliphatic side chain. There is little evidence of CYP metabolism. It has linear pharmacokinetics. Its clearance is increased by carbamazepine and to a lesser degree by oral contraceptives. Carisbamate slightly increases the clearance of valproic acid and lamotrigine. The most common adverse events in humans are headaches, dizziness, and somnolence, generally mild to moderate, occurring at doses of 1000 mg/day or more. A recently completed phase 2 study for adjunctive use in partial onset seizures showed efficacy at a dose that was well tolerated.

Topics: Animals; Anticonvulsants; Carbamates; Clinical Trials as Topic; Epilepsy; Humans

Although great advances have been made in the development of treatments for epilepsy, acquired epilepsy following brain injury still comprises approximately 50% of all the cases of epilepsy. Thus, development of drugs that would prevent or decrease the onset of epilepsy following brain injury represents an important area of research.. Here, we investigated effects of carisbamate (RWJ 333369) on the development and expression of spontaneous recurrent epileptiform discharges (SREDs) and its neuroprotective potential in cultured hippocampal neurons. This model utilizes 3 h of low Mg(2+) treatment to mimic status epilepticus (SE-like) injury in vitro. Following the injury, networks of neurons manifest synchronized SREDs for their life in culture. Neuronal cultures were treated with carisbamate (200 microM) for 12 h immediately after the SE-like injury. The drug was then removed and neurons were patch clamped 24 h following drug washout.. Treatment with carisbamate after neuronal injury prevented the development and expression of epileptiform discharges. In the few neurons that displayed SREDs following carisbamate treatment, there was a significant reduction in SRED frequency and duration. In contrast, phenytoin and phenobarbital, when used in place of carisbamate, did not prevent the development and expression of SREDs. Carisbamate was also effective in preventing neuronal death when administered after SE-like injury.. Carisbamate prevents the development and generation of epileptiform discharges and is neuroprotective when administered following SE-like injury in vitro and may offer a novel treatment to prevent the development of epileptiform discharges following brain injuries.

Topics: Action Potentials; Analysis of Variance; Animals; Animals, Newborn; Anticonvulsants; Carbamates; Cell Death; Cells, Cultured; Epilepsy; Hippocampus; Magnesium; Neurons; Patch-Clamp Techniques; Phenobarbital; Rats; Rats, Sprague-Dawley

Animal models with spontaneous epileptic seizures may be useful in the discovery of new antiepileptic drugs (AEDs). The purpose of the present study was to evaluate the efficacy of carisbamate on spontaneous motor seizures in rats with kainate-induced epilepsy.. Repeated, low-dose (5 mg/kg), intraperitoneal injections of kainate were administered every hour until each male Sprague-Dawley rat had experienced convulsive status epilepticus for at least 3 h. Five 1-month trials (n = 8-10 rats) assessed the effects of 0.3, 1, 3, 10, and 30 mg/kg carisbamate on spontaneous seizures. Each trial involved six AED-versus-vehicle tests comprised of carisbamate or 10% solutol-HS-15 treatments administered as intraperitoneal injections on alternate days with a recovery day between each treatment day.. Carisbamate significantly reduced motor seizure frequency at doses of 10 and 30 mg/kg, and caused complete seizure cessation during the 6-h postdrug epoch in seven of the eight animals at 30 mg/kg. The effects of carisbamate (0.3-30 mg/kg) on spontaneous motor seizures appeared dose dependent.. These data support the hypothesis that a repeated-measures, crossover protocol in animal models with spontaneous seizures is an effective method for testing AEDs. Carisbamate reduced the frequency of spontaneous motor seizures in a dose-dependent manner, and was more effective than topiramate at reducing seizures in rats with kainate-induced epilepsy.

Topics: Analysis of Variance; Animals; Anticonvulsants; Carbamates; Cross-Over Studies; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Administration Schedule; Epilepsy; Fructose; Kainic Acid; Male; Rats; Rats, Sprague-Dawley; Seizures; Time Factors; Topiramate; Video Recording

Carisbamate is a novel drug with neuromodulator activity that is currently under development for the treatment of epilepsy, diabetic neuropathy and neuralgia. The compound possessed a promising pharmacological profile in tests in vivo, and demonstrated broad anticonvulsant activity in preclinical studies, both elevating seizure threshold and preventing seizure spread. Carisbamate was also effective in protecting against spontaneous recurrent seizures in kainate-treated animals and in genetic models of epilepsy, and displayed antiepileptic and neuroprotective activity in the lithium-pilocarpine model of status epilepticus. In a phase I clinical trial, orally administered carisbamate demonstrated efficacy at high doses of 500 to 1000 mg. A phase II clinical trial confirmed that oral carisbamate was efficacious at a 300- to 1600-mg dose range. The preliminary evaluations of carisbamate in humans indicated complete absorption, extensive metabolism, and carbamate ester hydrolysis. The most frequently reported side effects associated with carisbamate are dizziness, headache, somnolence and nausea. In clinical trials, carisbamate did not display any significant interactions with commonly used antiepileptic drugs such as carbamazepine, valproate and lamotrigine. At the time of publication, a phase III clinical trial for carisbamate in the treatment of epilepsy was ongoing, as well as phase II trials in neuropathy and neuralgia. Data from preclinical brain injury studies with carisbamate and the analog RWJ-333369-A have also been reported. This drug profile will focus on the development of carisbamate in epilepsy.

Topics: Animals; Anticonvulsants; Carbamates; Controlled Clinical Trials as Topic; Disease Models, Animal; Drug Evaluation, Preclinical; Epilepsy; Humans; Patents as Topic