Adjunctive JNJ-42165279 fails to improve depression in SSRI/SNRI inadequate responders

JNJ-42165279 is a potent, selective inhibitor of fatty acid amide hydrolase (FAAH), the enzyme responsible for degradation of the endocannabinoid N-arachidonoylethanolamide (anandamide), which plays a role in regulation of fear and anxiety responses. This double-blind, randomised, placebo-controlled, phase 2a study assessed the efficacy, safety and pharmacodynamics of adjunctive treatment with JNJ-42165279 in participants with major depressive disorder (MDD) with anxious distress and inadequate response to selective serotonin reuptake inhibitors (SSRI) or serotonergic/noradrenergic reuptake inhibitors (SNRI). Eligible participants (18-64 years; N = 153) were randomised (1:1) to receive JNJ-42165279 (25 mg) or placebo orally once daily and were maintained on their current SSRI/SNRI treatment. The primary endpoint was the change from baseline at week 6 in the 17-item Hamilton Depression Rating Scale (HDRS). The study results did not show a significant treatment effect of adjunctive JNJ-42165279 on the primary endpoint versus placebo (least square mean difference [standard error]: -0.2 [1.04]; one-sided p=0.416) in the enriched intent-to-treat population. Findings for the key secondary efficacy endpoints also did not demonstrate an additional benefit of adjunctive JNJ-42165279 treatment over placebo. Treatment with JNJ-42165279 produced substantial increases in the mean concentrations of fatty acid amides in plasma, and the plasma JNJ-42165279 and anandamide levels were strongly correlated. The safety results were consistent with the known safety profile of JNJ-42165279. Overall, adjunctive treatment with JNJ-42165279 at the dose tested did not provide significant benefit in reducing depression/anxiety symptoms versus placebo but showed no new safety signals in participants with MDD and anxious distress.