Three phase III studies in Major Depressive Disorder (MDD) fail to meet primary endpoints

Allergan announced topline results from three pivotal phase III studies of GLYX 13 (rapastinel) as an adjunctive treatment of Major Depressive Disorder (MDD). In three acute studies (RAP-MD-01,-02,-03), the rapastinel treatment arms did not differentiate from placebo on the primary and key secondary endpoints. In all three acute studies rapastinel was well tolerated without any signal of psychotomimetic side effects. In addition, an interim analysis of the rapastinel relapse prevention study (RAP-MD-04) suggests the primary and key secondary endpoints will not be met.

Patients who completed the acute trials were eligible to enter the relapse prevention trial (RAP-MD-04). An interim analysis of (RAP-MD-04) was conducted of the primary and secondary efficacy endpoints of all randomized patients in the double-blind treatment period. At the time of the analysis, all patients had completed all visits relevant for determining a relapse. Detailed results from these studies will be presented at future scientific meetings.

Comment: Glutamate is the most prominent excitatory neurotransmitter in the brain, research suggests that dysfunction of the glutamatergic system may play a role in the neurobiology of MDD. The NMDA receptor is one of the glutamatergic receptors in the brain, and plays a critical role in learning, memory, and the strength of synaptic communication. The current research suggests that rapastinel may help relieve depression by enhancing NMDA receptor function.