Sarepta’s gene therapy could potentially reverse Duchenne Muscular Dystrophy

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Serapta Therapeutics have presented preliminary clinical trial data for their experimental gene therapy treatment of Duchenne muscular dystrophy (DMD). The data is significant enough to suggest that it can potentially halt or reverse the effects of the disease.

DMD is caused by a genetic defect affecting the production of dystrophin, a protein vital for muscle function. The results reported are from a Phase 1/2a clinical trial assessing Sarepta’s AAVrh74.MHCK7 gene therapy, conducted on three young males aged 4,5 and 6 who each received an injection of the therapy once a month over three months. After a three month follow up period, biopsies of the muscles were taken for comparison with initial biopsies.

The group found that mean gene expression measured by percentage of micro-dystropin positive fibers in each patient was 76.2%, and the mean intensity of the fibers was 74.5% compared to normal control. The post-treatment biopsies showed a mean micro-dystrophin production level of 38.2% above normal levels. Blood levels of creatine kinase, an enzyme used for DMD diagnosis, fell by a mean of 87%. Apart from two incidences of elevated gamma-glutamyl transferase, successfully resolved with a steroid treatment, no serious adverse events (SAEs) were observed.

Lead investigator Jerry Mendell of Nationwide Children’s Hospital in Columbus, Ohio, commented on the findings. “Although the data are early and preliminary, these results, if they persist and are confirmed in additional patients, will represent an unprecedented advancement in the treatment of DMD.”

Moving forward, Serepta plans to enrol 24 more boys from ages 4-7, with half receiving the gene therapy and half a placebo, with the primary trial endpoints being to study safety and measure micro-dystrophin production. They hope with the data gathered from this trial, they can move towards accelerated FDA approval.

Pfizer and Solid Bio are also working on gene therapy treatments for DMD, with Pfizer recently dosing their first patient.

Source:Sarepta Therapeutics Announces that at its First R&D Day, Jerry Mendell, M.D. Presented Positive Preliminary Results from the First Three Children Dosed in the Phase 1/2a Gene Therapy Micro-dystrophin Trial to Treat Patients with Duchenne Muscular Dystrophy; Press Release