rAAVrh74.MHCK7.micro-dystrophin is a medicinal product in clinical development for the treatment of children aged 3 months to 7 years with Duchenne muscular dystrophy (DMD). DMD is a rare progressive neuromuscular disorder caused by a gene mutation (change). DMD is caused by an absence of dystrophin, a protein that helps keep muscle cells intact. It affects mainly boys and symptoms often start before the age of five. DMD is a fatal condition with no cure. It causes progressive muscle weakness and often leads to loss of walking ability by the age of twelve, as well as problems with the heart and lungs. rAAVrh74.MHCK7.micro-dystrophin is a type of gene therapy, which delivers a functional version of the dystrophin gene via intravenous injection. rAAVrh74.MHCK7.micro-dystrophin, is based on a viral carrier to deliver a shorter version of the DMD gene, called micro-dystrophin. This shorter gene contains enough information to produce a protein that restores the function of dystrophin. If licensed, rAAVrh74.MHCK7.micro-dystrophin will provide a treatment option for male patients aged 3 months to 7 years with DMD.