Rare Daily Staff

The U.S. Food and Drug Administration has placed a clinical hold on Solid Biosciences phase 1/2 clinical trial for SGT-001, an experimental microdystrophin gene transfer therapy for the rare, progressive, fatal disease Duchenne muscular dystrophy.

The trial is designed to assess the safety and efficacy of SGT-001 in children and adolescents with DMD.

The first patient dosed in the clinical trial was a non-ambulatory adolescent who received SGT-001 on February 14, 2018. Several days after administration the patient was hospitalized due to laboratory findings that included a decrease in platelet count followed by a reduction in red blood cell count and evidence of complement activation.

The company said the patient showed no signs or symptoms of a bleeding disorder and no relevant changes from baseline in liver function tests. The patient responded well to medical treatment and is currently asymptomatic. All laboratory parameters have either improved or returned to normal, and he is continuing outpatient assessments per protocol.

Solid reported the event to the FDA and, because it was unexpected, classified it as a Suspected Unexpected Serious Adverse Reaction. The FDA informed the company that the clinical hold was due to the event. Solid has halted enrollment and dosing in trial and is awaiting the formal Clinical Hold letter from the FDA to understand the requirements for resuming the clinical trial.

SGT-001 is a novel adeno-associated viral vector-mediated gene transfer under investigation for its ability to address the underlying genetic cause of DMD, mutations in the dystrophin gene that result in the absence or near-absence of dystrophin protein. It is a systemically administered candidate that delivers a synthetic dystrophin gene, called microdystrophin, to the body.

The microdystrophin encodes for a functional protein surrogate that is expressed in muscles and stabilizes essential associated proteins. Data from Solid’s preclinical program suggests that SGT-001 has the potential to slow or stop the progression of DMD, regardless of genetic mutation or disease stage.

March 15, 2018