Usher Syndrome Therapeutics

Therapeutics: Where Are We?

Current treatments for Usher syndrome focus on helping an individual to adapt to hearing and vision loss and to maximising the vision and hearing that they do have. This includes the use of hearing aids, assistive listening devices, cochlear implants, mobility training, and low vision services. The wide range of assistive technologies available provides plenty of choice for users at all stages of sight and hearing loss and this technology has also removed many barriers to education and employment. Please see our section on Coping With a Diagnosis for more information on how to live well with Usher Syndrome.

Despite the lack of current treatments for Usher syndrome, general eye check-ups are important. This is because people with Usher syndrome are still at risk for other kinds of eye problems that can affect the general population, such as cataracts, and may be treatable. Regular visits to your eye doctor can also make you aware of current advances as we learn more about these conditions.

Where Are We Going?

Prospects for the development of effective Usher syndrome treatments have never been brighter. The syndrome is passed down through a recessive pattern of inheritance with only one pair of genes affected and is therefore a prime candidate for gene therapy. Gene therapy involves using harmless viruses to deliver and insert a healthy copy of the gene into the retina, thereby restoring function. This approach has led to exciting initial results in a number of other retinal diseases. Usher syndrome gene therapy is quite challenging as the genes affected tend to be extremely large in size and difficult to deliver. However, scientists are exploring other harmless viruses that have the ability to safely deliver these large genes. One trial is currently in the early stages of recruitment in the USA and France, and more trials are planned in the future.

Some forms of Usher syndrome are due to mutations known as “nonsense” mutations that lead to the incomplete and premature production of essential proteins. There are now new drugs in the very early stages of testing for a number of other rare genetic conditions due to nonsense gene mutations that may have the potential to stop the defective protein synthesis and produce the correct form of the protein. Neuroprotective agents that aim to preserve the function of the rod and cone photoreceptor cells for longer also hold huge potential for Usher syndrome, by maintaining a small, but significant amount of central vision.

Many of the therapies that are in development will not bring back the lost vision that occurs due to Usher syndrome, but they do have the potential to slow down or halt further degeneration, until other therapies, such as the exciting developments that have occurred in stem cell research, become available. Efforts at transplanting stem cell derived photoreceptor cells are still at an early stage of research, however a number of recent animal studies have shown the potential to restore function in the eye, which may pave the way for human studies in the future.

You can find a list of current trials related to IRDs here. You can also find trials by searching on the website that lists most clinical trials, however it must be noted that not all trials listed on the clinicaltrials.gov website are valid or vetted. Therefore, we always advise that you talk with your ophthamologist about possible clinical trials participation.

As can be seen from the recently approved gene therapy for biallelic REP65 LCA, Luxturna, many of these new treatments have a high price and are deemed to be very expensive. Therefore, while action is needed to maintain momentum in research and clinical trials to find these treatments, it is also of great importance to advocate for access to these treatments for all. Please see our Advocacy section for helpful information.