The international INCEPTUS study, a natural history study prior to the ASPIRO gene therapy trial to which I-Motion contributed, involved 34 children under 4 years of age with X-linked myotubular myopathy on respiratory support.
- During a median follow-up of 13 months (from 5 months to more than 2.5 years), there were three deaths (from inhalation pneumonitis, cardiorespiratory failure, and hepatic hemorrhage with peliosis) and 61 disease-related “serious events” in 20 participants, of which 52 were respiratory in 18 participants;
- 80% of participants had ventilatory support more than 16 hours/day (with a mean age of tracheostomy of 3.5 months) and 20% from 6 to 16 hours/day;
- 97% had a gastrostomy;
- 91% had liver damage (including eight before inclusion): during the study, 29 had at least one elevation of transaminases and 12 had an elevation of bilirubin; the liver ultrasound was not normal in nine cases;
- only seven participants could sit unsupported for more than 30 seconds (including one who later lost this ability); CHOP-INTEND scores ranged from 19 to 51.
- Respiratory and motor parameters remained stable throughout the study.
INCEPTUS Natural History, Run-in Study for Gene Replacement Clinical Trial in X-Linked Myotubular Myopathy. Dowling JJ, Müller-Felber W, Smith BK et al. J Neuromuscul Dis. 2022;9(4):503-516.