ProQR Therapeutics has dosed the first patient in a Phase I/II Aurora clinical trial to evaluate QR-1123 in patients with autosomal dominant retinitis pigmentosa (adRP).

The first-in-human study, Aurora (PQ-1123-001), will initially include up to 35 adults with adRP due to the P23H mutation in the rhodopsin (RHO) gene.

Single-dose escalation (open-label) groups and multiple-dose escalation (double-masked) groups in the trial will receive intravitreal injections of QR-1123 or sham procedures in one eye.

The trial’s objective is to evaluate the safety and tolerability of QR-1123.

ProQR Therapeutics Research & Development executive vice-president David Rodman said: “QR-1123 aims to block expression of the toxic mutated rhodopsin protein in the retina thereby targeting the underlying cause of the vision loss associated with adRP due to the P23H mutation.

“We are excited to have started a clinical trial for the third RNA therapy in our inherited retinal disease pipeline.”

ProQR will also assess efficacy as measured by improvement of visual function and retinal structure through ophthalmic endpoints such as visual acuity, visual field and optical coherence tomography.

The company plans to perform the trial at expert sites in North America and expects initial data in 2021.

QR-1123 was in-licensed from Ionis Pharmaceuticals last year and will be administered through intravitreal injections in the eye.

The therapy is a first-in-class investigational RNA-based oligonucleotide that has been designed to potentially treat adRP.

It specifically binds the mutated RHO mRNA and aims to inhibit the formation of the mutated toxic version of the rhodopsin protein.

QR-1123 secured Orphan Drug designation in the US and Fast Track designation from the FDA.

adRP, a severe and rare genetic disease, causes progressive problems in night vision during childhood and leads to visual field loss. It frequently results in blindness in mid-adulthood.