AMO Pharma has been conducting a Phase 2a clinical trial of Tideglusib (also known as AMO-02) for adolescents and adults with congenital myotonic dystrophy. Tideglusib is an antagonist for GSK3β, a cell signaling molecule thought to play a role in the pathogenesis of myotonic dystrophy. The AMO clinical trial is a single-blind study of 400 mg and 1000 mg doses of Tideglusib; single-blind means that those conducting the trial know the dose that each patient received and there was no placebo control included in the study. The study is being conducted at Newcastle University.

AMO recently reported interim data from the first cohort of 8 patients who received the 1000 mg dose of Tideglusib. Small, Phase 2a studies such as this are informative as to whether the candidate therapeutic is safe and well-tolerated. AMO reported that no trial subjects withdrew from the study as a result of adverse events or other issues.

Phase 2a studies also are used as a pilot to determine proof of the scientific concept as well as how various study endpoints perform in a particular patient group. Since there have been no prior clinical trials using novel drugs targeted to the brain in congenital myotonic dystrophy (CDM), multiple endpoint measures were explored to help in selection of endpoints for subsequent, definitive trials. AMO reported that data analysis was still ongoing, but that multiple endpoint measures indicated improvements that were statistically significant. With AMO’s focus on developing a drug to address brain manifestations of CDM, some of the endpoints showing improvement included central nervous system symptoms, autistic features and activities of daily living.

AMO Pharma is scheduled to present findings at the upcoming American Neurological Association meeting in San Diego in October. More complete information may be available after that presentation. Based upon these early stage results, AMO intends to launch a larger, multi-site study of Tideglusib in adolescents and children with CMD.

MDF is pleased to see candidate therapeutics moving forward for myotonic dystrophy and appreciates AMO Pharma’s efforts. To date, their results suggest that the drug does not have safety concerns and the positive data from the exploratory endpoints examined here suggest that it could prove effective for CDM. We await the launch and completion of a definitive, multi-site, placebo-controlled controlled trial, the gold standard for the regulatory authorities, for Tideglusib.