New treatments for hearing loss are on the horizon
Forty-eight million Americans have significant hearing loss in one ear and 30 million Americans have hearing loss in both ears. One would think with numbers like that, drug treatments would be readily available. Yet there are no drugs currently on the market, making hearing loss an underserved malady. But, according to a January New York Times article, things are starting to change, bringing new hope to those with hearing loss and allowing for possible prevention of hearing loss in the future.
Why the sudden interest in hearing-related pharmaceuticals now? Population demographics offer a big clue: The baby boomer generation. This generation, those born between 1946 and 1964, represents a huge portion of the population. In fact, 76 million people in the United States are now between the ages of 50 and 68. With more people over the age of 50, there are (presumably) more people with hearing loss, so treating or preventing age related hearing loss is becoming more of a priority.
As such, drug companies are starting to see the benefit in throwing their proverbial hat into the ring when it comes to hearing health; the bottom line is that eldercare represents a huge slice of the pie for the pharmaceutical industry. In the past few years there has been an explosion of new companies with an interest in treating and preventing hearing loss. And certain specific hearing issues are not far away from having treatments available on the market.
Let’s look at tinnitus as an example. According to the National Institute on Deaf and other Communication Disorders (NIDCD), up to 10 percent of the adult population experiences tinnitus for more than three months each year. Typically in the past the cause of the tinnitus has been treated, but not the tinnitus itself; through the use of behavioral therapy or devices that mask the sound, the tinnitus itself can be masked, but certainly not eliminated.
Even for Meniere’s disease, which often is accompanied by tinnitus, vertigo and hearing loss, the best currently available treatment involves steroid injections. The problem is that the patient must remain completely still for 30 minutes after the injection, and injections must occur many times over the course of two weeks. Even with all of this, only a fraction of the drug actually makes it into the inner ear. In an effort to solve the problem, a new company called Otonomy came up with a way to suspend the steroid in a polymer. Though liquid at room temperature, the polymer turns to a gel when it reaches body temperature. The polymer slowly dissolves over the course of a week, releasing the steroid gradually. This is called “sustained exposure.” Otonomy is now working on applying that same polymer technology to other drug treatments.
While some companies are exploring new drugs to treat age-related hearing loss, other companies such as Auris Medical are focused on loss of hearing caused by trauma or exposure to ototoxic medications. Auris, for example, has found an effective treatment that works when applied with 48 hours of a traumatic hearing loss. They are also working on a derivative of ketamine, an anesthetic, as a possible treatment for tinnitus.
The most cutting-edge technology is perhaps gene therapy, aimed at regenerating hair cells in order to reverse the effects of noise exposure and ototoxicity. Novartis is currently in a clinical trial of gene therapy aimed at restoring lost hearing. Though nothing is definitive yet, there have been whispers of positive results in early clinical trials.
Even stem-cell therapy is getting its day when it comes to hearing loss. According to a 2013 article, scientists discovered that both adult AND embryonic stem cells exist in the inner ear, along with scientific evidence that they can be converted into hair cells, paving the way for the possibility of stem-cell based treatment for hearing loss in the future.
While some companies are focused on the inner ear, others are focused on the central nervous system where sound is processed. For example, Autifony Therapeutics is focused on age-related hearing loss, and helping the brain interpret signals from the auditory nerve. At this writing, Autifony is looking to partner with big pharma to further their research. And a study at University of Australia is testing the drug furosemide as a treatment for tinnitus; it works by lowering the activity of the auditory nerve, thus reducing neural hyperactivity in the part of the brain that processes sound. Said Dr. Helmy Mulders, lead researcher, in a press release: “Studies in human tinnitus sufferers are still needed to confirm our results but lowering the activity of the auditory nerve may be a promising approach.”
While it's always a good idea to see a hearing healthcare professional, don’t expect these new treatments to be available just yet. All are still in various stages of clinical trials. But now that small companies are showing results, big companies are sitting up and taking notice. And with big drug companies jumping on board, the future for new drug treatments is looking much brighter. For now, if you are experiencing any symptoms of hearing loss, including tinnitus and dizziness, contact your hearing healthcare professional today. If you don't have a regular hearing health physician, check out our hearing clinic directory to find a reviewed doctor near you.