The question of the duration of clinical and biological monitoring after gene therapy remains under debate, particularly beyond 18 months:
- a survey was conducted among thirteen laboratories involved in clinical gene therapy protocols using adeno-associated viruses (AAV),
- out of 24 programmes listed, the vast majority of adverse effects were noted and documented in the first three months after administration,
- and extending monitoring to longer periods was not always dictated by regulatory considerations.
The authors therefore argue for a relaxation and harmonisation of the rules in this area, which would reduce the costs of toxicity studies and increase the attractiveness of AAV-mediated gene therapies.
