Study of EDG-5506 now enrolling adults with Becker MD

GRAND CANYON trial is testing Edgewise Therapeutics' experimental therapy

Marisa Wexler, MS avatar

by Marisa Wexler, MS |

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A Phase 2 clinical trial testing the investigational oral medication EDG-5506 in people with Becker muscular dystrophy (BMD) is expanding, with plans to enroll 120 additional adults with the genetic disorder.

According to EDG-5506’s developer Edgewise Therapeutics, enrollment in the expanded study is ongoing. The company is hosting a website that offers details about the trial, as well as a survey that patients can take to see if they are eligible to participate.

If findings from the study are positive, they could support applications seeking regulatory approvals of EDG-5506 as a treatment for BMD.

“This study is critical for the Becker community, as there currently are no approved treatments for Becker, a condition that for far too long has been neglected,” Joanne Donovan, MD, PhD, Edgewise’s chief medical officer, said in a press release.

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BMD is caused by mutations that disrupt the function or significantly lower the production of dystrophin, a protein that normally functions like a shock absorber inside of muscle cells, helping to cushion muscles against damage. In BMD, a lack of functional dystrophin causes muscles to accumulate more wear-and-tear damage over time, ultimately leading to symptoms like muscle weakness.

EDG-5506 is designed to block the activity of myosin, a key protein that muscles use to contract. By blocking this protein, the therapy aims to make muscle contractions less forceful so that there’s less wear-and-tear, ultimately helping preserve muscle function over time.

In a Phase 1 clinical trial called ARCH (NCT05160415), most men with BMD who were treated with EDG-5506 had stable or improved motor function after a year on therapy. That is a notable contrast to the typical progression of the disease, where motor function usually worsens as time goes on. Markers of muscle damage also were reduced by EDG-5506 treatment in the Phase 1 study.

Edgewise has been running a Phase 2 trial called CANYON (NCT05291091), testing EDG-5506 against a placebo in adolescents and adults with BMD, ages 12 to 50. The study already has enrolled more patients than originally planned, with 39 adults and 24 adolescent participants.

Adding new group to the CANYON study

Based on the positive one-year findings from ARCH, Edgewise announced plans to add a new cohort to the CANYON study. The new cohort, called GRAND CANYON, is expected to include an additional 120 adults ages 18 to 50. Participants will be enrolled at up to 50 sites in 10 countries, including the U.S., the Netherlands, and the U.K.

“Based on the strength of safety, functional and biomarker results from our ARCH open label study, we have rapidly initiated this ground-breaking clinical study,”  Donovan said.

In order to be eligible for participation, patients must be able to walk at least 100 meters (almost 110 yards), with or without an assistive device, in less than 200 seconds (slightly more than three minutes). As in the original CANYON study, participants in GRAND CANYON will be given either a placebo or EDG-5506 at doses ranging from 5 to 12.5 mg per day.

The study’s main goals are to assess the experimental treatment’s safety profile and its effect on measure of motor function and markers of muscle damage. Treatment will last 18 months.

GRAND CANYON study expected to be pivotal

The GRAND CANYON expansion was designed similarly to a Phase 3 clinical trial, and it’s expected to be pivotal (meaning positive results could support applications seeking regulatory approval).

“It is exciting to move to the next stage of testing of the clinical hypothesis that a reduction in contraction-induced muscle damage has the potential to benefit people living with muscular dystrophies. Having seen promising preclinical results with EDG-5506 translate clinically, I am thrilled we are entering into a pivotal study,” said Alan Russell, PhD, co-founder and chief scientific officer of Edgewise.