Efficacy and safety of JNJ-42165279, a fatty acid amide hydrolase inhibitor, in adolescents and adults with autism spectrum disorder: a randomized, phase 2, placebo-controlled study.

JNJ-42165279, a highly selective and orally bioavailable fatty acid amide (FAA) hydrolase inhibitor, was evaluated for efficacy and safety in adolescents and adults with autism spectrum disorder (ASD) in this phase 2, double-blind, placebo-controlled, multicenter study (NCT03664232). Participants aged 13-35 years, with a diagnosis of ASD (Diagnostic and Statistical Manual of Mental Disorders, 5th edition; Autism Diagnostic Observation Schedule, 2nd edition) were randomized (1:1) to 12 weeks of treatment with JNJ-42165279 (25 mg, twice-daily) or placebo. Primary endpoints were the change in the Autism Behavior Inventory (ABI) Core Domain (ABI-CD), ABI-Social Communication (ABI-SC), and ABI-Repetitive/Restrictive Behavior (ABI-RB) scores from baseline to day 85. Of the 61 participants (16 female, 45 male) included in the efficacy analyses, 53 (87%) completed the double-blind treatment. At day 85, the JNJ-42165279 group did not show a statistically significant reduction in ASD symptoms versus placebo, as assessed with ABI-CD (p = 0.284), ABI-SC (p = 0.290), and ABI-RB (p = 0.231). However, the following secondary outcomes exhibited small to moderate changes directionally favoring JNJ-42165279: Social Responsiveness Scale 2 (SRS, p = 0.064), Repetitive Behavior Scale-Revised (RBS-R, p = 0.006), Zarit Burden Interview short version (ZBI, p = 0.063), Child Adolescent Symptom Inventory-Anxiety (CASI-Anx, p = 0.048), and Caregiver Global Impression of Severity (p = 0.075). Notably, versus placebo, JNJ-42165279-treated participants showed increased concentrations of FAAs throughout the treatment period, with those achieving elevated concentrations experiencing the greatest reduction in the SRS total score at day 85. JNJ-42165279 demonstrated an acceptable safety profile. Although primary endpoints were not met, JNJ-42165279 may have a therapeutic effect on certain aspects of core ASD symptoms.