A Study of Balovaptan in Adults With Autism Spectrum Disorder With a 2-Year Open-Label Extension

A Phase III, Randomized, Double-Blind, Placebo-Controlled, Efficacy, and Safety Study of Balovaptan in Adults With Autism Spectrum Disorder With a 2-Year Open-Label Extension

This study will evaluate the efficacy, safety, and pharmacokinetics of 10 mg of oral administration balovaptan once a day (QD) compared with matching placebo in adults (18 years and older) with autism spectrum disorder (ASD).

Inclusion Criteria:

• Subject meets the DSM-5 criteria for ASD for an autism diagnosis and is confirmed using ADOS-2 criteria
• SRS-2, proxy version, total t-score >=66 at screening
• A full scale IQ score >=70 on the WASI®-II
• Subject has an appropriate study partner, in the opinion of the investigator
• For women of childbearing potential: agreement to remain abstinent or use a contraceptive method with a failure rate of <1% per year during the treatment period and for at least 28 days after the last dose of study drug
• Treatment with permitted medications (at a stable dose for 12 weeks before screening) and behavioral therapy regimens (regimens stable for 6 weeks before screening), with the intent that such treatments remain stable throughout the study and with no expected changes before the Week 24 visit

Exclusion Criteria:

• Pregnancy or breastfeeding, or intention to become pregnant during the study
• Previous initiation of new or major change in psychosocial intervention within 6 weeks prior to screening
• Unstable or uncontrolled clinically significant affective or psychotic disorders and/or neurologic disorder that may interfere with the assessment of safety or efficacy endpoints
• Substance use disorders during the last 12 months
• Significant risk for suicidal behavior, in the opinion of the investigator
• Epilepsy or seizure disorder considered not well controlled within the past 6 months or changes in anticonvulsive therapy within the last 6 months
• Clinical diagnosis of peripheral neuropathy
• Within the last 2 years, unstable or clinically significant cardiovascular disease
• Uncontrolled hypertension
• Unexplained syncopal episode within the last 12 months
• Confirmed elevation above upper limit of normal of CK-MB, high sensitivity cardiac troponin T, cardiac troponin I, and/or N-terminal pro B-type natriuretic peptide
• Positive serology results for hepatitis B surface antigen (HBsAg), hepatitis C virus (HCV) antibody, or human immunodeficiency virus (HIV) 1 or 2
• History of coagulopathies, bleeding disorders, blood dyscrasias, hematological malignancies, myelosuppression (including iatrogenic), or current major bleeding event
• Concomitant disease or condition that could interfere with, or treatment of which might interfere with, the conduct of the study, or what would, in the opinion of the investigator, pose an unacceptable risk to the subject in this study
• Confirmed clinically significant abnormality in parameters of hematology
• Confirmed clinically significant abnormality in parameters of clinical chemistry, coagulation, or urinalysis
• Medical history of malignancy, if not considered cured