AST-001 versus placebo for social communication in children with autism spectrum disorder: A randomized clinical trial.

Aim: This study examined the efficacy of AST-001 for the core symptoms of autism spectrum disorder (ASD) in children.

Methods: This phase 2 clinical trial consisted of a 12-week placebo-controlled main study, a 12-week extension, and a 12-week follow-up in children aged 2 to 11 years with ASD. The participants were randomized in a 1:1:1 ratio to a high-dose, low-dose, or placebo-to-high-dose control group during the main study. The placebo-to-high-dose control group received placebo during the main study and high-dose AST-001 during the extension. The a priori primary outcome was the mean change in the Adaptive Behavior Composite (ABC) score of the Korean Vineland Adaptive Behavior Scales II (K-VABS-II) from baseline to week 12.

Results: Among 151 enrolled participants, 144 completed the main study, 140 completed the extension, and 135 completed the follow-up. The mean K-VABS-II ABC score at the 12th week compared with baseline was significantly increased in the high-dose group (P = 0.042) compared with the placebo-to-high-dose control group. The mean CGI-S scores were significantly decreased at the 12th week in the high-dose (P = 0.046) and low-dose (P = 0.017) groups compared with the placebo-to-high-dose control group. During the extension, the K-VABS-II ABC and CGI-S scores of the placebo-to-high-dose control group changed rapidly after administration of high-dose AST-001 and caught up with those of the high-dose group at the 24th week. AST-001 was well tolerated with no safety concern. The most common adverse drug reaction was diarrhea.

Conclusions: Our results provide preliminary evidence for the efficacy of AST-001 for the core symptoms of ASD.