Safety and Efficacy of Mutation-targeted Precision Genetic Therapy for Ataxia-Telangiectasia (A-T)

The goal of this protocol is to study the safety and efficacy of the investigational drug atipeksen, a mutation-specific antisense oligonucleotide (ASO), in individuals with ataxia telangiectasia (A-T). The first objective is to evaluate the safety of therapy with atipeksen, a 22-nucleotide oligonucleotide designed to ameliorate the effects of mis-splicing caused by a mutation in the ATM gene(NM\_000051.3), c.7865C\>T (p.Ala2622Val), when administered via intrathecal injection. The second objective is to determine if administration of intrathecal atipeksen can reduce or stabilize neurological decline using clinical and physiological biomarkers. The primary endpoint will be serial clinical neurologic assessments using the Ataxia-Telangiectasia Neurological Examination Toolkit (A-T NEST) and a structured version of the Ataxia-Telangiectasia Clinical Global Impression of Change (A-T CGI). Secondary endpoints will include videotaped clinical neurological examinations, movement pattern analyses using wearable actigraphy, and standard scales administered by PT, OT, and neuropsychology. Exploratory endpoints include serial brain imaging with volumetric analyses, neurofilament light chain, alpha-fetoprotein, and growth parameters.