Researchers at Duke University have shown that a single systemic treatment using CRISPR genome editing technology can safely and stably correct Duchenne muscular dystrophy (DMD) for more than a year in mice.
Nature Medicine has published the study, in which investigators administered a single dose of the CRISPR therapy intravenously to both adult and newborn mice carrying a defective dystrophin gene.
Over the course of the following year, they measured how many muscle cells were successfully edited and what types of genetic alterations were made, as well as the generation of any immune response against the bacterial CRISPR protein, Cas9.
Investigators observed that when two-day-old mice without fully developed immune systems were treated intravenously, no immune response was detected. The CRISPR genome editing remained stable and, in some cases, even strengthened over the course of a year.
"Even though we observed both antibody and T cell responses to Cas9, neither appeared to result in any toxicity in these mice," said researcher Christopher Nelson, adding "the response also did not prevent the therapy's ability to successfully edit the dystrophin gene and produce long-term protein expression.”
DMD is a genetic disorder characterised by progressive muscle degeneration and weakness, caused by an absence of dystrophin, a protein that helps keep muscle cells intact, suggesting approaches to address potential challenges, should they arise in the future