While Zolgensma gene therapy is only indicated for children weighing less than 21 kg with type I SMN1-related proximal spinal muscular atrophy (SMA) or who carry a biallelic mutation of the SMN1 gene and a maximum of three copies of the SMN2 gene, a Chinese team has tested a new gene therapy, GC101.
- Like Zolgensma, GC101 is a recombinant gene therapy based on adeno-associated virus serotype 9 (AAV9) that aims to deliver the functional SMN1 gene.
- GC101 treatment was administered as a single intrathecal injection to six patients with SMA type II and three patients with SMA type III, aged between six months and 18 years, with one year of follow-up.
- No serious adverse events related to the treatment (primary endpoint) were reported.
- Motor function improved or remained stable in all patients.
- The two patients who were able to walk were assessed using the 6-minute walk test, which showed clinically significant improvement for both. Their gait improved during follow-up and one of them was able to jump.
- The five patients whose motor function had declined prior to treatment were able to recover their overall motor abilities. One of them was able to stand without support at week 32.
- The earlier the treatment is started, the greater the benefits.
Studies involving a larger number of patients and longer observation periods will be necessary to better understand the effect of GC101 in patients with SMA types II and III.
