ProQR, a developer of RNA therapies in the Netherlands, announced that the first clinical-trial participant has received its emerging treatment, which targets retinitis pigmentosa and Usher syndrome caused by mutations in exon 13 of the USH2A gene. The Phase 1/2 clinical trial is taking place at Retina Foundation of the Southwest in Dallas and the University of Michigan in Ann Arbor. Known as QR-421a, the treatment is intended to slow or potentially reverse vision loss.
The Foundation Fighting Blindness is investing up to $7.5 million through its RD Fund to move QR-421a into and through the early stage clinical trial. The RD Fund, a venture philanthropy fund, was established in 2018 to provide investments for promising retinal degenerative disease therapies that are in, or moving toward, early human studies.
QR-421a is an antisense oligonucleotide (AON) — a small piece of genetic material — designed to mask exon 13 mutations in the RNA of USH2A. RNA are genetic messages that cells read to make proteins critical to their health and function. QR-421a enables retinal cells to skip over exon 13 (and any mutations inside it) when reading the USH2A RNA, enabling the cells to make functional protein that will hopefully halt or slow the disease process and vision loss.
In September 2018, ProQR reported vision improvements for patients in a Phase 1/2 clinical trial for QR-110, an AON therapy for people with Leber congenital amaurosis 10 (LCA10) caused by the p.Cys998X mutation in the CEP290 gene. The company reported that 60 percent of subjects in the trial demonstrated improvements in visual acuity and their ability to navigate a mobility course. The treatment was also safe for patients. As a result of the encouraging interim results, ProQR concluded the Phase 1/2 trial and is moving the treatment into a Phase 2/3 clinical trial.
“We are excited about ProQR’s innovative AON technology for treating inherited retinal diseases,” says Brian Mansfield, PhD, executive vice president of research and interim chief scientific officer at the Foundation. “It is an elegant approach for addressing certain genetic conditions and has shown encouraging early results for LCA10.”