A new gene therapy has given exceptional results on 9 children with myotubular myopathy (MTM). The disease causes extreme muscle weakness, which occurs immediately after birth. All the small patients have recovered part of the muscular functions, so that 4 of them can breathe on their own.
The trial involved 9 children from 8 months to 6 years of age, all suffering from X-linked myotubular myopathy. The doctors gave them an intravenous infusion, containing billions of viruses rendered harmless. The viruses injected a corrected version of the MTM1 gene into the patients' muscle cells, eliminating the abnormal one. In this way they restored myotubularin production.
The therapy caused serious side effects in 3 patients, including cardiac inflammation. The doctors were able to tackle all these problems, which then came back. At 48 weeks after therapy, the muscle cells of the first 6 patients were producing about 85% of normal myotubularin levels. The muscle fibers had grown and 4 of them were able to sit alone; 3 even managed to walk with a little help. While continuing to receive artificial nutrition, several of them also began to eat normal food.
Some patients were able to articulate a few words. Doctors gave a higher dose of gene therapy to 3 patients. In these cases, the scientists detected the same improvements but many weeks in advance. Encouraging results, but to be confirmed with further studies and trials.