rAAV.hCNGA3

rAAV.hCNGA3 is a gene therapy product designed to treat CNGA3-linked achromatopsia, a rare inherited retinal disorder. This therapy uses an adeno-associated virus serotype 8 (AAV8) as a vector to deliver a functional copy of the human CNGA3 gene to cone photoreceptors in the retina[1][6]. The therapy is administered through a single subretinal injection, aiming to restore cone function in patients with this condition[1][5]. rAAV.hCNGA3 works through gene supplementation therapy. It uses the AAV8 serotype as a viral capsid, combined with a cone-specific arrestin-3 (ARR3) promoter and human CNGA3 complementary DNA to specifically target and transduce cone photoreceptors[6]. By delivering a functional copy of the CNGA3 gene to these cells, the therapy aims to restore the cyclic nucleotide-gated channel function that is impaired in patients with CNGA3 mutations[2][6]. The therapy has been evaluated in clinical trials, including a phase 1/2 study known as the Colourbridge trial (NCT02610582)[8]. This trial, initiated in 2015 by research groups at the University Hospital Tübingen and the Ludwig Maximilian University of Munich, tested three different doses (1×10^10, 5×10^10, and 1×10^11 vector genomes) in nine adult patients with CNGA3-linked achromatopsia[5][6]. The primary endpoint of safety was met with an excellent safety profile. Only mild immune responses were reported in two patients, which were resolved with corticosteroids[6]. Interestingly, despite foveal detachment during the procedure, best corrected visual acuity slightly improved (-0.05±0.02 logMAR)[5]. The 1-year clinical evaluation revealed improvements in overall cone function, including visual acuity and contrast sensitivity[6].

Other names

AAV8-hCNGA3AAV-8-hCNGA3AAV 8-hCNGA3CNGA3 gene therapyCNGA-3 gene therapyCNGA 3 gene therapy