{Reference Type}: Clinical Trial, Phase II {Title}: A Phase 2 Study of AMO-02 (Tideglusib) in Congenital and Childhood-Onset Myotonic Dystrophy Type 1 (DM1). {Author}: Horrigan J;Gomes TB;Snape M;Nikolenko N;McMorn A;Evans S;Yaroshinsky A;Della Pasqua O;Oosterholt S;Lochmüller H; {Journal}: Pediatr Neurol {Volume}: 112 {Issue}: 0 {Year}: 11 2020 {Factor}: 4.21 {DOI}: 10.1016/j.pediatrneurol.2020.08.001 {Abstract}: GSK3β is an intracellular regulatory kinase that is dysregulated in multiple tissues in type 1 myotonic dystrophy, a rare neuromuscular disorder that manifests at any age. AMO-02 (tideglusib) inhibits GSK3β activity in preclinical models of type 1 myotonic dystrophy and promotes cellular maturation as well as normalizes aberrant molecular and behavioral phenotypes. This phase 2 study assessed the pharmacokinetics, safety and tolerability, and preliminary efficacy of AMO-02 in adolescents and adults with congenital and childhood-onset type 1 myotonic dystrophy.
Sixteen subjects (aged 13 to 34 years) with congenital and childhood-onset type 1 myotonic dystrophy received 12 weeks of single-blind fixed-dose oral treatment with either 400 mg (n = 8) or 1000 mg (n = 8) AMO-02 (NCT02858908). Blood samples were obtained for pharmacokinetic assessment. Safety assessments, such as laboratory tests and electrocardiograms, as well as efficacy assessments of syndromal, cognitive, and muscular functioning, were obtained.
AMO-02 plasma concentrations conformed to a two-compartment model with first-order absorption and elimination, and dose-dependent increases in exposure (area under the curve) were observed. AMO-02 was generally safe and well-tolerated. No early discontinuations due to adverse events or dose adjustments of AMO-02 occurred. The majority of subjects manifested clinical improvement in their central nervous system and neuromuscular symptoms after 12 weeks of treatment compared with the placebo baseline, with a larger response noted at the 1000 mg/day dose level. AMO-02 exposure (cumulative area under the curve) was significantly correlated (P < 0.01) with change from baseline on several key efficacy assessments.
AMO-02 has favorable pharmacokinetic and clinical risk/benefit profiles meriting further study as a potential treatment for congenital and childhood-onset type 1 myotonic dystrophy.