Our investigational RNA therapy, QR-421a, aims to stop vision loss in people with a mutation in a specific part of the USH2A gene, called exon 13. QR-421a works by binding to the mutated USH2A RNA and exclude exon 13 from the RNA. This approach is known as exon skipping. The cells in the retina can then produce a slightly shorter but functional USH2A protein.
The Stellar study is a Phase 1/2 clinical trial of QR-421a to test whether it is safe and leads to better vision. The interim findings from the trial were encouraging, announced in March 2020. Today, a year later, the positive results of the trial have been announced. With only one injection of QR-421a, the Stellar study showed benefit in the treated eye in comparison to the untreated eye across multiple eye tests. We have seen this benefit across all participants in the Stellar study, which included clinical trial participants with both advanced vision loss as well as early to moderate vision loss.
For more information on the safety & efficacy of the trial, please read our Community statement QR-421a program results (and translations in Dutch and French).
ProQR plans to advance QR-421a into final stage clinical testing. This will be our second clinical program to move into the final stage, following our final stage clinical testing in Leber Congenital Amaurosis type 10 (LCA10). The news today further validates our RNA therapy platform and our capabilities to design and efficiently take these programs through clinical development.