BYLINE: Jodie Nicotra

Newswise — For years, much of the most promising research on hearing loss has focused on looking for its genetic causes. Now the tide may be shifting to include pharmaceutical and gene therapies, according to a recent talk on the state of research in the field.

Adrien A. Eshraghi, M.D., a recognized expert in hearing research from the University of Miami Miller School of Medicine, spoke at the American Academy of Otolaryngology-Head and Neck Surgery Foundation (AAO-HNSF). Often called “The Academy” by participants, the conference is considered the preeminent one in the field.

For the fifth year in a row, Dr. Eshraghi, professor of otolaryngology, neurosurgery and pediatrics at the Miller School, and his co-presenter, Ronna Hertzano, M.D., Ph.D., chief of the neurotology branch at the National Institutes of Health, were invited to lecture on the year’s most important hearing loss research.

Narrowing the Research Field

The process of identifying that research begins with Dr. Eshraghi and Dr. Hertzano mobilizing their respective labs to select the 20 most impactful articles from the past year.

“These are the papers that can be judged to have interesting, novel findings that can impact the future of our practice in the field,” said Dr. Eshraghi.

The two then meet to discuss their selections and select around 30 papers that they use as the basis of their lecture, “The Leading Edge: What’s New in Hearing Research?”

In this year’s lecture, Dr. Eshraghi and Dr. Hertzano zeroed in on four categories of leading-edge research in hearing loss: gene therapy research, implantable hearing aid devices like cochlear implants, stem cell therapies and drug therapies.

Gene therapy, especially for a form of congenital deafness caused by the deficiency of the protein otoferlin, has shown significant promise with early, positive clinical trial outcomes. Therapy for patients with this hearing loss involves introducing functional copies of the otoferlin genes into the inner ear.

Dr. Eshraghi cautions that, despite the demonstrated effectiveness of otoferlin therapies in clinical trials, gene therapy is currently still limited in what it can address.

“There are interesting results from gene therapy for a specific disorder, but all the advertisements that come out of that shouldn’t hide from us the fact that we are still rather far away from the time that we can treat all kinds of genetic deafness by gene therapy,” he said.

Cochlear Implants

Early positive results from otoferlin gene therapy clinical trials should not prevent patients, especially children, from seeking other forms of therapies like cochlear implant, currently considered the standard of care for congenital deafness.

“We want children to have access to hearing as early as possible because it’s imperative in their development of not only hearing but language and communication,” Dr. Eshraghi said.

Cochlear implants are now well-established as an accepted hearing loss treatment for patients as young as nine months. But research from this past year shows promising new directions.

Some of the most impactful research this year on cochlear implantation identified by Dr. Eshraghi and Dr. Hertzano includes work on outcomes for patients with inner-ear tumors known as acoustic neuromas or vestibular schwannomas. They also highlighted studies on OTOPLAN, a 3D visualization software that helps with cochlear implantation surgery, and work discussing improvements in sound localization and spatial recognition for patients with single-sided deafness who receive a cochlear implant.

Drug Therapies for Hearing Loss

Perhaps the most interesting new research concerned clinical trials with new drugs for hearing loss. Pharmaceutical research has flourished lately, evidenced by the number of clinical trials for new drugs for certain types of acquired hearing loss.

The new flush of drug therapy research can be partly attributed to the recognition that a significant market for such products exists.

Historically, pharmaceutical companies have been reluctant to invest in treatments for hearing loss, as it was perceived to affect a relatively small population compared to conditions like high blood pressure. 

However, Dr. Eshraghi said, the landscape is shifting.

“Companies are now becoming aware that there are a lot of people with hearing loss and tinnitus. So they’ve become more focused, more interested in that area, which results in more research, more publications, and more clinical trials. It’s very encouraging,” he said.

Dr. Eshraghi’s recently published book, “Overcoming Hearing Loss,” aims to educate not only ENTs, but primary care physicians, emergency room doctors, nurse practitioners and patients on causes and treatments for hearing loss. It includes chapters on drug and gene therapies as well as cochlear implant surgery.