Leucovorin for the Treatment of Language Impairment in Children With Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a heterogeneous neurodevelopmental disorder often with life-long consequences that affects young children during critical developmental periods. The Centers for Disease Control estimates that ASD affects as many as 14.7 per 1000 children (1 in 68). Despite the dramatic rise in the detected prevalence of ASD over the past two decades, no effective medical treatment has been developed to address core ASD symptoms (social communication and repetitive behavior), the closely associated problem of language impairment, or the underlying pathophysiology of ASD. Currently, the only accepted treatment for core ASD symptoms is behavior therapy, which may entail intensive one-on-one treatment over several years. The purpose of this study is to determine the effectiveness of folinic acid in the treatment of language problems in children with autism spectrum disorder. Folinic acid, also known as leucovorin, is approved by the U.S. Food and Drug Administration (FDA) to decrease side effects during cancer chemotherapy. Folinic acid may be helpful in treating language problems in children with autism spectrum disorder, but this is not known. Therefore, folinic acid is an investigational new drug for this study. The primary aims of this study are to evaluate the efficacy and tolerability of high-dose folinic acid for improving the closely associated symptoms of language impairment in children with autism spectrum disorder (ASD). Improvement in delayed language may also benefit the core ASD problem of social communication. The study will also focus on identification of biomarkers in pre-specified subgroups of children with ASD that may moderate positive response to folinic acid. The study model is that high-dose folinic acid will improve language and set the stage for improved social communication in children with ASD and moderate language impairment. To test whether folinic acid is superior to placebo, 134 children (age 5 to 17 yrs 6 months, inclusive) with ASD and moderate language will be randomly assigned to folinic acid or placebo for 12 weeks under double-blind conditions. The study team will also test whether abnormalities in folate-dependent pathways, such as dysfunctional transport of folate across the blood-brain barrier, will moderate positive response to folinic acid treatment.