Tideglusib Improves Myotonic Dystrophy Type 1 Neuromuscular Symptoms

Michael Snape, PhD, the chief executive and chief scientific officer of AMO Pharma

Michael Snape, PhD

The results of a phase 2 trial of an investigational therapy, tideglusib (AMO-02, AMO Pharma), have suggested that the treatment is associated with improvements in cognitive function, fatigue, and neuromuscular symptoms in myotonic dystrophy type 1 (DM1).

In a dose of 1000 mg, the novel and oral glycogen synthase kinase 3 (GSK-3ß) enzyme inhibitor rendered a clinical benefit for the majority of patients after a 12-week treatment period.¹ Four of the 10 efficacy variables assessed, including grip strength, Clinician Visual Analogue Scale rating, Caregiver Top 3 Concerns rating scale, and Ohio State University Clinical Global Impression of Improvement rating scale, differed in favor of the 1000-mg dose over the 400-mg dose, with no worsening in the remaining 6 variables.

The results were presented by Michael Snape, PhD, the chief executive and chief scientific officer of AMO Pharma, in a podium presentation at the 7^th International Conference on Neurology and Neuromuscular Diseases in Madrid, Spain.

"Standard measures of treatment efficacy are often not well defined for underserved disease states such as DM1," Snape said in a statement.² "This concordant trend analysis offers important new insights that can help us better identify the most precise and appropriate measures of efficacy and safety in clinical research involving AMO-02 and potentially other therapies in the years ahead."

These findings, AMO announced, reinforce previous data from other study findings, mirroring the results that showed most patients treated with tideglusib experienced at least 1 clinical benefit after 12 weeks of treatment, more so with a 1000-mg dose compared to a 400-mg dose. The phase 2a trial explored the utility of tideglusib in 16 adolescent and adult patients with DM1, with outcome measures including disease-specific rating scales, functional and performance-based assessments, and biomarkers.

The trend analysis not only provided reiterative assurance the findings but provide an important bit of potential in an area that lacks gold standard outcome measures. Notably, this was the first clinical trial conducted in this specific patient population, according to AMO Pharma.

"This analysis provides a more nuanced understanding of the potential for AMO-02 to offer benefits in the treatment of DM1," said Joseph Horrigan, MD, chief medical officer of AMO Pharma. "These results reinforce the decision to advance the clinical development of AMO-02 to a registration-caliber clinical trial for the treatment of DM1."

The developer also announced that it is now advancing the development of tideglusib in the treatment of congenital DM1 in an ongoing 6-month registration-caliber study. Results from that trial will also be assessed with a primary outcome measure based on a clinician-completed rating scale, specific to congenital DM1.

In May 2017, the GSK-3ß inhibitor was granted a Fast Track Designation by the FDA.³ The Investigational New Drug application process for the therapy began in the year prior.

REFERENCES

1. Snape M. The utility of concordant trend analyses in a phase 2 study in congenital and

childhood onset

myotonic dystrophy type 1: a case example. Presented at: 7^th International Conference on Neurology and Neuromuscular Diseases; Madrid, Spain; October 23, 2018. neuromuscular.pulsusconference.com/2018/abstract/the-utility-of-concordant-trend-analyses-in-a-phase-2-study-in-congenital-and-childhood-onset-myotonic-dystrophy-type-1-a-case-example. Accessed October 30, 2018.

2. AMO Therapeutics Announces Presentation of Concordant Analysis of Results of Phase 2 Study of AMO-02 in

treatment

of myotonic dystrophy [press release]. Durham, NC: AMO Pharma Limited; Published October 23, 2018. prnewswire.com/news-releases/amo-therapeutics-announces-presentation-of-concordant-analysis-of-results-of-phase-2-study-of-amo-02-in-treatment-of-myotonic-dystrophy-300736162.html. Accessed October 30, 2018.

3. AMO Pharma Announces FDA Fast Track Designation For AMO-02 For Treatment Of Congenital Myotonic Dystrophy [press release]: Philadelphia, PA: AMO Pharma Limited; Published May 30, 2017. prnewswire.com/news-releases/amo-pharma-announces-fda-fast-track-designation-for-amo-02-for-treatment-of-congenital-myotonic-dystrophy-300464282.html. Accessed October 30, 2018.