hearingA growing number of pharma companies are pursuing drugs for the ear, according to a recent article in The New York Times.

A clinical trial recently began of a gene therapy being developed by Novartis that is aimed at restoring lost hearing, according to the article.

A drug that improves hearing or silences ringing in the ears (tinnitus) has not yet been developed, but some companies are report promising early clinical trials.

About 48 million Americans have a meaningful hearing loss in at least one ear; 30 million of them have it in both ears, Dr. Frank R. Lin, an associate professor of otolaryngology and geriatric medicine at Johns Hopkins University, told The Times.

A drug to treat or prevent age-related hearing loss “will be something that people take every day for the rest of their life,” Edwin W. Rubel, a professor of hearing science at the University of Washington and co-founder of a start-up called Oricula Therapeutics, said in the article. “Even if it could just delay age-related hearing loss by five or 10 years, that would be wonderful.”

Past attempts to develop ear drugs have largely failed. The inner ear, key to hearing and balance, is almost impenetrable, making it difficult to study or for drugs to enter, according to the article.

Genetic and animal studies reveal more about how the ear works, according to pharm execs. About 15,000 hair cells in the cochlea, part of the inner ear, are crucial to hearing -- they send signals to the auditory nerve leading to the brain. These hair cells can be damaged by loud noise, by disease, by exposure to certain medicines, or by the passage of time. And hair cells do not regenerate; once they are destroyed the loss is permanent, according to The Times.

One clinical trial of gene therapy is aimed at regenerating hair cells. The trial is being sponsored by Novartis and uses a gene therapy developed by GenVec, a Maryland biotech company.

Other companies are trying to improve hearing or prevent hearing loss from trauma such as loud noises or exposure to the chemotherapy drug cisplatin or a widely used class of antibiotics known as aminoglycosides, according to the article.

Companies are also working on drugs for tinnitus. Approximately ten percent of American adults, or 25 million people, have experienced at least one episode of five minutes or more in the past year where sound is perceived without a source of the sound being present, according to the National Institute on Deafness and Other Communication Disorders.

Tinnitus treatments include behavioral therapy and devices that can mask the sound. But these are largely coping mechanisms. Some drugs like steroidsand lidocaine are used off label, according to the article.

One drug in late-stage trials aims to dampen the dysfunctional signaling in the auditory nerve that is perceived as tinnitus. In a mid-stage trial, the drug, injected into the middle ear, was not more effective than a placebo. But a subset of patients whose tinnitus was caused by trauma or infection said the drug made the sound in their ears softer, less annoying and less disruptive of sleep, according to the article.

Source: The New York Times