A gene therapy clinical trial for Duchenne muscular dystrophy (DMD) by Sarepta Therapeutics had begun in the Nationwide Children’s Research Institute. The gene therapy drug, rAAvrh.74.MHCK7 or “micro-dystrophin”, was being studied as a potential therapy for patients with Duchenne muscular dystrophy (DMD).
Ian Estepan a representative for Sarepta said that the purpose of this trial was to, “assess the safety and tolerability of the drug in individuals with DMD.”
During quality assurance testing, a DNA fragment was found within a plasmid used in the gene therapy. At this time, the US Food and Drug Administration (FDA) contacted the Nationwide Children’s Research Institute and the trial has since been put on a clinical hold.
The plasmids, a typical part of gene therapy in early phase gene therapy clinical trials, were research grade.
None of the plasmids that demonstrated the presence of a fragment of DNA were given to patients, nor did any of the DNA fragment show up in patient biopsies. Hutman stated that the plasmid material came from a third-party manufacturer.
“The research institute, working with Sarepta Therapeutics, has developed their action plan with immediate plans to submit for review by the FDA,” said Estepan “Subject to the FDA’s acceptance of the action plan, Sarepta therapeutics does not anticipate any material delay in dosing patients as originally planned by year-end 2018.”
Micro-dystrophin, the gene therapy drug being tested, provides a smaller version of the dystrophin genes DMD patients lack.
An earlier trial with only three patients showed positive results, as they began to produce enough dystrophin to potentially reverse DMD.
DMD is a genetic disorder that presents muscle degeneration and weakness, caused by a lack of dystrophin. Dystrophin is a protein that works to keep muscle cells intact. The disorder primarily affects boys and is very rarely seen in girls, with the onset of the disorder seen between ages three to five.