Potential drug treatments for retinitis pigmentosa and Usher syndrome
A company called ProQR Therapeutics has announced a drug in development called QRX-411, which is currently at the Orphan Drug Designation stage by the FDA and European medicines agency (EMA) for the treatment of retinitis pigmentosa. QRX-411 is a candidate drug, meaning a potential drug that still needs a full evaluation, which we hope will target retinitis pigmentosa and also Usher syndrome, which is a cause of deafness and blindness due to a genetic defect.
Orphan Drug status is a designation granted to drugs that can treat diseases that affect less than 200,000 people in the US. ProQR Therapeutics is a US company. The status being given to QRX-411 makes it eligible for seven years in the US and ten years in the EU of marketing following its approval for Usher syndrome. The orphan drug designation also makes the company benefit in terms of tax credits on an exemption from the FDA user fees plus assistance from the FDA in the clinical trial design.
I have read that the QRX-411 targets severe degenerative retinal disease for which there are no other treatments available to restore vision or indeed impede the progression of the disease. The QRX-411 targets mutations in the USH2A gene and pre-clinical trials have shown some positive results.
The company is also trialling drugs for other genetic retinal conditions for which currently there are no therapies available. It is looking at a drug called QR-110 for Leber’s congenital amaurosis type 10, which has also been given orphan drug designation in the US and Europe.
It is developing QRX-1011 for Stargardt’s disease and QRX-504 for Fuchs’ endothelial corneal dystrophy.
There are so many potential genetic therapies in the pipeline that five years from now we will writing very different blogs and many more patients will be receiving treatments that either improve their vision or slow down deterioration through these developing therapies for ophthalmology using the novel RNA oligonucleotides drug discovery platform.
If you would like to know more about potential treatments on the horizon for inherited retinal disease, you may discuss these at consultation with Professor Michel Michaelides at Clinica London, who is a world-leading expert on inherited retinal diseases and is involved in many trials internationally and nationally.
Inherited retinal diseases affect the retina, which is clear from their name, and are the commonest cause severe impairment vision and blindness in young adults of working age in the Western World. There is an enormous loss to the economy if these patients with IRD cannot work. There is an enormous amount of hope for those patients with IRD over the next few years.
Patients are required to enrol in trials as each IRD only affects a small number of patients, and each IRD is different.