ML-004 - (IRIS)

June 22, 2026: MapLight Therapeutics, Inc. (NASDAQ: MPLT) reported topline results from IRIS (ML-004-002), a Phase 2 randomized, double-blind, placebo-controlled trial of ML-004 in autism spectrum disorder (ASD) (N=161; 102 adolescents, 59 adults). The study did not meet its primary endpoint: change from baseline to Week 12 in caregiver-reported Autism Behavioral Inventory (ABI) Social Communication Domain score.

In a prespecified subgroup of adolescents (12–17) with moderate or greater baseline irritability (ABC-I >16; N=20), ML-004 showed clinically meaningful improvement vs placebo on caregiver-reported Aberrant Behavior Checklist–Irritability (ABC-I) (LS mean difference −9.58; effect size 1.33; nominal p=0.013) and clinician-rated CGI-I Irritability domain (LS mean difference −0.63; effect size 1.08; nominal p=0.036). In the overall ABC-I >16 population (ages 12–45; N=26), effect size was 0.64 (nominal p=0.13) on ABC-I at Week 12.

Safety: ML-004 was generally well tolerated; no severe/serious AEs in the active arm, no extrapyramidal events, and mean weight gain was lower than placebo. The company plans an FDA End-of-Phase 2 meeting to discuss next steps. Separately, Phase 2 ZEPHYR topline results for ML-007C-MA in schizophrenia are expected by mid-August 2026.