American researchers have analysed the causes of death of a 27-year-old Duchenne muscular dystrophy (DMD) patient who took part in the first trial using the CRISPR-Cas9 system for therapeutic purposes in this disease:
- the patient had received a single intravenous injection of an AAV9-mediated genome-editing product at a dose of 1×1014 vector-genome per kilo of body weight,
- on the sixth day post-injection, cardiac and then respiratory failure was noted, leading to his death two days later,
- on the basis of additional tests, the authors incriminate an innate immune reaction rather than a response directed against the transgene or the CRISPR-Cas9 system itself.
