The US Food and Drug Administration (FDA) has granted authorisation for Edgewise Therapeutics’ Phase II clinical trial of EDG-5506 for treating duchenne muscular dystrophy (DMD) in children. 

Named LYNX, the trial is expected to begin dosing subjects in the fourth quarter of this year. 

The placebo-controlled trial will evaluate the safety, pharmacokinetics (PK), and muscle damage biomarkers following three doses of EDG-5506 given over 12 weeks.

It will enrol nearly 27 DMD patients aged four to nine years on stable corticosteroids at up to 12 US sites. 

To obtain additional insights into safety and functional measures, the subjects will be part of the trial’s open-label extension portion for 12 months. 

The trial will also aid in selecting the doses of the therapy that could potentially lower muscle damage biomarkers and offer functional benefits to patients in a Phase III trial.

An investigational, oral, small molecule, EDG-5506 is a myosin modulator. 

It can offer protection to fast skeletal muscle fibres that are susceptible to injury in dystrophinopathies such as DMD and Becker muscular dystrophy (BMD).

Edgewise Therapeutic chief medical officer Joanne Donovan said: “Our team has worked with key opinion leaders and patient advocacy groups to thoughtfully design our LYNX Phase II clinical trial. 

“The promising tolerability and changes in biomarkers of muscle damage that we have seen in studies with EDG-5506 in individuals with BMD supports our next step of expanding enrolment to individuals with DMD.”

A degenerative genetic disorder, DMD is characterised by gradual muscle function impairment.

The company has concluded a Phase I trial of EDG-5506 in healthy adult subjects (Phase 1a) and adult BMD patients (Phase 1b).

In a follow-on, single-centre, open-label trial named ARCH, the molecule showed durable safety and PK and also lowered muscle damage biomarkers. 

In July this year, Edgewise began the Phase II CANYON trial of EDG-5506 in BMD patients.