Faced with a scenario of the sudden loss of hearing or sight, the political activist and deaf-blind author Helen Keller told a friend that deafness is a far worse plight. Many of the estimated 66,000 people in the United States who experience sudden hearing loss each year likely feel the same way.
The condition, which physicians call sudden sensorineural hearing loss, or SSHL, is an unexplained, rapid loss of hearing—usually in one ear. About half of the people who experience it will regain most or all of their hearing spontaneously, but the other half will not. Elias Michaelides, MD, an ear, nose, and throat physician at Yale Medicine, wants to improve those odds through a clinical trial to test a new drug for this condition.
The trial, open to anyone in New England, has an unusual requirement for enrollment: Since it’s important to treat SSHL quickly, a patient must receive the drug (called AM-111) within three days of noticing hearing loss. “The hardest part is getting patients in our doors within that time frame,” Dr. Michaelides says.
Patients and physicians can call 203-584-8404 24 hours a day to learn about enrolling in the trial.
Difficult to find a cause
Many people who notice they aren’t hearing well delay talking to their doctor about the problem because they assume the sudden blockage is caused by a build-up of ear wax. Even doctors may take extra time trying to identify a reason for the hearing loss, since SSHL is somewhat rare—it affects about 5 to 20 people per 100,000 each year—and they don’t see it very often.
But the fact is, most people who experience SSHL never learn why it occurs. The most common scenarios are to awaken one morning, suddenly unable to hear, or to notice a rapid decline in hearing over several days. Though researchers agree that inflammation within the inner ear is most often the cause, it’s a difficult condition to diagnose because the act of opening the inner ear to explore the inside causes deafness. In rare cases, a culprit—such as a virus or microscopic blood clot—may be pinpointed.
The organ affected by SSHL, the delicate cochlea in the inner ear, contains thousands of sound-sensing hair cells. When they’re damaged, for whatever reason, they can’t be repaired and new hairs do not grow to replace them.
If SSHL is caught quickly, oral steroids may help by reducing inner-ear inflammation, which might save some hair cells from being damaged. But steroids do not reliably improve hearing in all patients, so researchers aren’t sure how much they help. The hope is that this new drug—AM-111—will both stabilize the injured cells and prevent other hair cells from dying. AM-111 works by penetrating cochlear cells and interrupting the process of cells death (known as apoptosis). Trial patients receive the drug in the form of a gel, which is inserted via a needle through the eardrum into the middle ear after first receiving a local anesthetic. The gel soaks the inner ear for 30 minutes. The tiny hole in the eardrum seals up on its own within two days.
The clinical trial
Earlier this year, AM-111 received Fast Track designation status from the Food and Drug Administration (FDA). Granting this status indicates that the FDA recognizes that AM-111 treats a serious and unmet medical need. It allows the pharmaceutical company to have greater access to FDA officials during the drug review process. If approved by the FDA, AM-111 would be the first drug specifically for SSHL, according to Swiss-based Auris Medical, the pharmaceutical company developing it. Yale Medicine is one of 45 organizations in the U.S., Canada, Asia and Europe running the Phase 3 clinical trial, called ASSENT. Auris Medical aims to enroll a total of 300 patients by 2018.
Patients in the trial will receive medication, hearing and blood tests and five doctor appointments over a period of three months for free. There is also a $100 debit card stipend per visit. To be enrolled, a person must have experienced a loss of hearing equal to or greater than 60 decibels. This means that someone who previously had normal hearing is able to hear only very loud noises and words spoken directly into the damaged ear. Dr. Michaelides describes this as “a very big loss” of hearing.
Participants must also have a health record free of previous SSHL for the past two years. The study divides patients into three groups. Two groups receive AM-111 at different dosage levels. The third group receives a placebo. Patients have a 66 percent chance of receiving the new drug.
Dr. Michaelides says that people who have made a partial or full recovery from SSHL with steroids, or even with no treatment at all, feel deeply grateful when they get some or all of their hearing back. “When people are asked which sense they would rather lose, sight or hearing, they usually say hearing,” he says. “But for people who have actually lost their sight and hearing, they always say they want their hearing back.”
Source: Yale University