Brexpiprazole in Treatment of Children and Adolescents With Irritability Associated With Autism Spectrum Disorder (Anchor)

Brexpiprazole in Treatment of Children and Adolescents With Irritability Associated With Autism Spectrum Disorder

A Phase 3, Multicenter, Randomized, Double-blind, Placebo Controlled Trial of Brexpiprazole in Treatment of Children and Adolescents With Irritability Associated With Autism Spectrum Disorder

The purpose of this study is to find out about the potential benefits and safety of brexpiprazole in children and adolescent participants, aged 5 to 17, with irritability associated with autism spectrum disorder.

Participants received flexible doses of brexpiprazole 0.25 to 3 milligram per day (mg/day), orally, once daily (QD) up to Week 8. For participants with body weight < 50 kilograms (kg) the dose was titrated up from 0.25 mg/day on Days 1 to 3, followed by 0.5 mg on Days 4 to 7, and to 1 mg on Days 8 to 14. Based on the investigator's judgment the dose was increased to 1.5 mg/day after Day 15. The dose was fixed after Week 6 and administration continued for another 2 weeks until Week 8. For participants with body weight ≥ 50 kg the dose was titrated up from 0.5 mg/day on Days 1 to 3, followed by 1.5 mg on Days 4 to 7, and to 2 mg on Days 8 to 14. Based on the investigator's judgment the dose was increased to 3 mg/day after Day 15. The dose was fixed after Week 6 and administration continued for another 2 weeks until Week 8.

Participants received brexpiprazole matching placebo orally, QD, in the same way as brexpiprazole up to Week 8.

The mean change from baseline to Week 8 in the Aberrant Behavior Checklist- Irritability subscale score (ABC-I)

The mean change from baseline to Week 8 in the Clinical Global Impression- Severity of Illness Scale (CGI-S) score pertaining to irritability

Key Inclusion Criteria: Primary Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) diagnosis of ASD Aberrant Behavior checklist - Irritability (ABC-I) subscale score of ≥ 18 Clinical Global Impressions - Severity (CGI-S) scale score pertaining to irritability ≥ 4 Mental age of ≥ 2 years as determined by Investigator based upon school participation, social history or medical records Ability for parent/caregiver to follow all protocol procedures Able to swallow tablets Able to discontinue all prohibited concomitant medications to meet protocol required washouts prior to and during the trial period Key Exclusion Criteria: Primary diagnosis of bipolar I disorder, including any DSM-5 current diagnosis of bipolar II disorder, schizophrenia, schizoaffective disorder, major depressive episode, and post-traumatic stress disorder (PTSD). Attention-deficit/hyperactivity disorder (ADHD) maybe exclusionary if it is the primary disorder, or is not stable or adequately treated. current or historical diagnosis of Fragile-X Syndrome or Rett's Disorder history of neuroleptic malignant syndrome a significant risk of committing violent acts, serious self-harm, or suicide epilepsy, a history of seizures, or a history of severe head trauma or stroke, or have a history or current evidence of other unstable medical conditions current hypothyroidism or hyperthyroidism uncontrolled Type I or Type II diabetes uncontrolled hypertension or symptomatic hypotension, or orthostatic hypotension Weight < 15 kg Previous exposure to brexpiprazole Sexually active males or females, who could become pregnant, not agreeing to practice 2 different methods of birth control or remain abstinent during the trial and for 30 days at the end of the study