The therapeutic trials leading to the approval of the onasemnogene abeparvovec (Zolgensma) were conducted in children with SMA weighing less than 8.5 kg. In the framework of a compassionate access programme set up by Novartis for this innovative therapy (GMAP programme), this weight limit could be exceeded:
- 102 children have been treated since September 2021 for this broader indication;
- five of them even weighed more than 13.5 kg when injected;
- for 53% of the children treated, side effects, mostly minor, have been reported;
- three patients died of respiratory infection, but apparently unrelated to the treatment itself;
- liver toxicity, thrombocytopenia, vomiting and fever were also transiently reported .
These results confirm a good tolerance of the gene therapy product above 8.5kg.
