Low‐dose suramin in autism spectrum disorder: a small, phase I/II, randomized clinical trial

<jats:title>Abstract</jats:title><jats:sec><jats:title>Objective</jats:title><jats:p>No drug is yet approved to treat the core symptoms of autism spectrum disorder (<jats:styled-content style="fixed-case">ASD</jats:styled-content>). Low‐dose suramin was effective in the maternal immune activation and Fragile X mouse models of <jats:styled-content style="fixed-case">ASD</jats:styled-content>. The Suramin Autism Treatment‐1 (<jats:styled-content style="fixed-case">SAT</jats:styled-content>‐1) trial was a double‐blind, placebo‐controlled, translational pilot study to examine the safety and activity of low‐dose suramin in children with <jats:styled-content style="fixed-case">ASD</jats:styled-content>.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>Ten male subjects with <jats:styled-content style="fixed-case">ASD</jats:styled-content>, ages 5–14 years, were matched by age, <jats:styled-content style="fixed-case">IQ</jats:styled-content>, and autism severity into five pairs, then randomized to receive a single, intravenous infusion of suramin (20 mg/kg) or saline. The primary outcomes were <jats:styled-content style="fixed-case">ADOS</jats:styled-content>‐2 comparison scores and Expressive One‐Word Picture Vocabulary Test (<jats:styled-content style="fixed-case">EOWPVT</jats:styled-content>). Secondary outcomes were the aberrant behavior checklist, autism treatment evaluation checklist, repetitive behavior questionnaire, and clinical global impression questionnaire.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>Blood levels of suramin were 12 ± 1.5 <jats:italic>μ</jats:italic>mol/L (mean ± SD) at 2 days and 1.5 ± 0.5 <jats:italic>μ</jats:italic>mol/L after 6 weeks. The terminal half‐life was 14.7 ± 0.7 days. A self‐limited, asymptomatic rash was seen, but there were no serious adverse events. <jats:styled-content style="fixed-case">ADOS</jats:styled-content>‐2 comparison scores improved by −1.6 ± 0.55 points (<jats:italic>n</jats:italic> = 5; 95% <jats:styled-content style="fixed-case">CI</jats:styled-content> = −2.3 to −0.9; Cohen's <jats:italic>d</jats:italic> = 2.9; <jats:italic>P</jats:italic> = 0.0028) in the suramin group and did not change in the placebo group. <jats:styled-content style="fixed-case">EOWPVT</jats:styled-content> scores did not change. Secondary outcomes also showed improvements in language, social interaction, and decreased restricted or repetitive behaviors.</jats:p></jats:sec><jats:sec><jats:title>Interpretation</jats:title><jats:p>The safety and activity of low‐dose suramin showed promise as a novel approach to treatment of <jats:styled-content style="fixed-case">ASD</jats:styled-content> in this small study.</jats:p></jats:sec>