JNJ-40411813 is a positive allosteric modulator (PAM) of the metabotropic glutamate receptor-2 (mGlu2), which is abundantly expressed in the forebrain and cerebellum. The mGlu2 receptor functions as a presynaptic auto-receptor that, upon activation, decreases the release of the excitatory neurotransmitter glutamate. Positive allosteric modulation of a receptor will result in the direct enhancement of the agonist-induced signal while PAMs themselves have generally no or low intrinsic activity at the receptor. The net effect of JNJ-40411813 is hypothesized to be a normalization of hyper-glutamatergic transmission. JNJ-40411813 is being evaluated for the treatment of disorders of the central nervous systems (CNS), such as epilepsy, and has been evaluated in schizophrenia and anxious depression. This study will consist of 1 to a maximum of 3 cohorts. In each cohort, for each participant the study consists of a screening period (up to minus [-] 8 weeks), an 8-week prospective pretreatment baseline period, an up to 12-week double-blind treatment period and a 2-year OLE period or a follow-up telephone visit 2 weeks after the last dose of study intervention. Safety assessments including physical and neurological examination, vital signs, 12 lead electrocardiogram (ECG), clinical chemistry, hematology, and urinalysis will be performed. The total maximal duration of the study is up to 2 years and 5 months.
The purpose of this study is to evaluate the efficacy of up to 3 dose levels of adjunctive JNJ-40411813 compared to placebo based on the time to baseline monthly seizure count in participants with focal onset seizures who are receiving levetiracetam or brivaracetam and up to 3 other anti-epileptic drugs (AEDs) (double-blind treatment period) and to evaluate the long-term efficacy and safety of adjunctive therapy with JNJ-40411813 in participants with epilepsy (open-label extension [OLE] period).