Also known as Helsmoortel–Van Der Aa syndrome, ADNP syndrome is caused by mutations in the ADNP gene. Studies in animal models suggest that low-dose ketamine increases expression of ADNP and is neuroprotective.
Intrigued by the preclinical evidence, Alexander Kolevzon, MD, clinical director of the Seaver Autism Center at Mount Sinai, New York, and colleagues treated 10 children with ADNP syndrome with a single low dose of ketamine (0.5mg/kg) infused intravenously over 40 minutes. The children ranged in ages 6-12 years.
Using parent-report instruments to assess treatment effects, ketamine was associated with “nominally significant” improvement in a variety of domains, including social behavior, attention-deficit and hyperactivity, restricted and repetitive behaviors, and sensory sensitivities.
Parent reports of improvement in these domains aligned with clinician-rated assessments based on the Clinical Global Impressions–Improvement scale.
The results also highlight the potential utility of electrophysiological measurement of auditory steady-state response and eye-tracking to track change with ketamine treatment, the researchers say.
The study was published online in Human Genetics and Genomic (HGG) Advances.
Ketamine was generally well tolerated. There were no clinically significant abnormalities in laboratory or cardiac monitoring, and there were no serious adverse events (AEs).
Treatment emergent AEs were all mild to moderate and no child required any interventions.
The most common AEs were elation/silliness in five children (50%), all of whom had a history of similar symptoms. Drowsiness and fatigue occurred in four children (40%) and two of them had a history of drowsiness. Aggression was likewise relatively common, reported in four children (40%), all of whom had aggression at baseline.
Decreased appetite emerged as a new AE in three children (30%), increased anxiety occurred in three children (30%), and irritability, nausea/vomiting, and restlessness each occurred in two children (20%).
The researchers caution that the findings are intended to be “hypothesis generating.”
“We are encouraged by these findings, which provide preliminary support for ketamine to help reduce negative effects of this devastating syndrome,” Dr. Kolevzon said in a news release from Mount Sinai.
Ketamine might help ease symptoms of ADNP syndrome “by increasing expression of the ADNP gene or by promoting synaptic plasticity through glutamatergic pathways,” Dr. Kolevzon told this news organization.
The next step, he said, is to get “a larger, placebo-controlled study approved for funding using repeated dosing over a longer duration of time. We are working with the FDA to get the design approved for an investigational new drug application.”
Support for the study was provided by the ADNP Kids Foundation and the Foundation for Mood Disorders. Support for mediKanren was provided by the National Center for Advancing Translational Sciences, and National Institutes of Health through the Biomedical Data Translator Program. Dr. Kolevzon is on the scientific advisory board of Ovid Therapeutics, Ritrova Therapeutics, and Jaguar Therapeutics and consults to Acadia, Alkermes, GW Pharmaceuticals, Neuren Pharmaceuticals, Clinilabs Drug Development Corporation, and Scioto Biosciences.
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