Enrollment Starts for Phase 2/3 Trial of Oral Therapy for Congenital DM1

AMO Pharma has begun enrollment for a Phase 2/3 trial that will assess the experimental oral therapy AMO-02 (tideglusib) in children and adolescents with congenital myotonic dystrophy type 1 (DM1).

The randomized, double-blind trial (NCT03692312) is intended to support regulatory approval of AMO-02 for congenital DM1, also known as Steinert disease. Its start follows discussions with regulators on the trial’s design and outcome measures, as well as $35 million in investor funding.

The trial will test the safety and efficacy of AMO-02 in an estimated 56 patients ages 6 to 16 with congenital DM1 who are able to walk (ambulatory).

Taking place at 10 treatment centers across the United States, Canada and the United Kingdom, the study will evaluate the patients’ central nervous systems (brain and spinal cord) and muscle function after daily doses of either placebo or a weight-adjusted 400 mg, 600 mg, or 1,000 milligrams of AMO-02 for 22 weeks. More information on locations and contacts can be found here.

Based on recent financing, AMO Pharma has the resources necessary to complete the AMO-02 clinical program,” Mike Snape, PhD, the company’s CEO, said in a press release. “We are working with our outstanding team of clinical investigators to advance this development program as rapidly as possible.”

Currently approved medications — in addition to commonly prescribed physical and speech therapy — only help manage symptoms of DM1. The disease, Snape said, “represents a significant area of unmet need in global health, with few and only inadequate and unapproved treatment options available.”

AMO-02 is intended to reach the brain, muscle, and other tissues to reduce expanded CTG repeats in the DMPK gene — the disease’s underlying cause. CTG refers to cytosine, thymine and guanine — three of the building blocks of DNA.

Preclinical studies have linked DM1 and Duchenne muscular dystrophy to abnormally high activity of an enzyme known as glycogen synthase kinase 3 beta (GSK3beta). AMO-02 is designed to block the enzyme, improving muscle characteristics in patients’ tissue samples.

A Phase 2 trial (NCT02858908) of AMO-02 in adolescents and adults with myotonic dystrophy was completed in 2018. The study included 16 participants with congenital and juvenile-onset DM1 aged 13 to 34, who received daily treatment with either AMO-02 (400 mg or 1,000 mg) or a placebo.

The therapy improved trial participants’ cognition and ability to perform daily tasks, while easing autism symptoms and fatigue. According to reports from physicians and caregivers, the medicine improved patients’ conditions throughout the study. Participants given the higher (1,000 mg) dose responded better than those on 400 mg. Treatment with AMO-02 was safe and well tolerated.