Usher Syndrome, the most common cause of combined deafness and blindness, currently lacks a cure, but emerging therapies are offering new hope. The market, valued at approximately USD 77 million across the 7MM in 2023, is expected to grow as novel treatments move through the pipeline.
Understanding Usher Syndrome
Usher Syndrome (USH) is a genetic condition characterized by hearing loss and retinitis pigmentosa, a progressive degeneration of the retina. Balance disorders can also occur. Diagnosing Usher Syndrome involves hearing, balance, and vision tests, along with genetic testing. Currently, management focuses on supportive care, including hearing aids, visual aids, and vitamin supplements. Luxturna is the only approved therapy for retinal degeneration, which is a common feature of Usher Syndrome, but is only effective in a small subset of patients.
Emerging Therapeutic Approaches
Several companies are developing therapies to address the underlying causes of Usher Syndrome. Nacuity Pharmaceuticals is investigating NPI-001, a purified form of N-acetylcysteine amide (NACA), in a Phase I/II trial (NCT04355689). NPI-001 acts as a free radical scavenger, aiming to reduce oxidative stress and preserve photoreceptor cells. Preclinical studies have shown that NPI-001 can protect photoreceptor cells and maintain their function.
Laboratoires Thea is developing Ultevursen (formerly QR-421a), an investigational RNA therapy designed to address mutations in exon 13 of the USH2A gene, which are associated with Usher Syndrome type 2a. Ultevursen is designed to restore functional usherin protein by using an exon-skipping approach with the aim of stopping or reversing vision loss in patients. Ultevursen is currently being evaluated in the Phase II/III SIRIUS trial. The FDA has granted Ultevursen Orphan Drug Designation, Fast Track designation, and Rare Pediatric Disease designation.
Market Dynamics and Future Outlook
The US has the highest prevalence of Usher Syndrome, with approximately 21,000 cases in 2023. Germany has the highest prevalence in EU4 and the UK, while Spain has the lowest. Type 2 Usher Syndrome accounts for over 60% of cases in the US. The market is expected to grow significantly between 2024 and 2034, driven by the introduction of new therapies. Ultevursen is projected to generate the highest revenue among emerging therapies in the US by 2032.
While vitamin A supplementation is sometimes recommended to slow retinal degeneration, a comparison of clinical trials showed no significant difference in visual acuity with different doses of vitamin A and vitamin E, suggesting that vitamin supplementation may have limited benefit. This highlights the urgent need for effective treatments that target the underlying genetic defects in Usher Syndrome.
Ongoing research into the function of Usher proteins in auditory and visual cells will be crucial for developing optimal gene replacement therapies and other targeted treatments. The development of therapies like NPI-001 and Ultevursen represents a significant step forward in addressing the unmet needs of Usher Syndrome patients.
