Henry Ford Health System has launched a clinical trial to investigate a new drug for the treatment of tinnitus, a chronic ringing of the head or ears that affects more than 600 million people worldwide.
The study will examine AM-101, a gel injected into the middle ear, to determine its safety and effectiveness in lessening the excessive signaling to the brain that occurs with acute inner ear tinnitus, most often caused by noise trauma or infection.
AM-101 inhibits certain receptors in the inner ear that are thought to play a key role in the development of tinnitus. This inhibitory effect has been investigated and confirmed in animal behavior models.
Henry Ford is one of 70 sites worldwide involved in this National Institutes of Health-supported study and it is currently recruiting patients.
"More recent theories assume that, while it starts in the ear, tinnitus becomes 'centralized' in the brain over time, where it can persist even if the original damage is no longer present in the inner ear," says study lead investigator Michael D. Seidman, M.D., director of the Division of Otologic/Neurotologic Surgery in the Department of Otolaryngology-Head & Neck Surgery at Henry Ford.
"Since the chances of a cure for this type of permanent tinnitus are very low, attempts are being made to treat the tinnitus at an early stage, focusing on the inner ear."
Notably, tinnitus affects more than 12 percent of American troops who have been exposed to acoustic trauma from machinery and explosive devices. It is now the No. 1 disability among women and men in uniform a growing problem that costs the U.S. roughly $1.7 billion a year to treat.
Tinnitus in the inner ear is often a consequence of an acoustic trauma, barotrauma, operation on the middle ear, traumatic perforation of the eardrum or middle ear infection. While the tinnitus often goes away after a short period in these circumstances, it can persist in some cases even after the injury has healed.
For its study, Henry Ford will recruit patients who have experienced tinnitus for three months or fewer following traumatic cochlear injury or otitis media, an inflammation of the middle ear.
In an outpatient procedure, the study drug AM-101 or a placebo will be injected into the middle ear, where it then passes into the inner ear, following the administration of a local anesthetic to the eardrum. The injection will be repeated two more times during a five-day period.
Patients in the study also will need to return for several follow-up visits.
Throughout the study, patients will be asked each evening to answer two short questions on the loudness of the tinnitus and the associated annoyance in an electronic diary.
In order to investigate the efficacy of AM-101, it must be possible to compare the improvement in the tinnitus after the injection with a control group. Therefore, some of the participants will receive a placebo preparation. Neither the patient nor the study doctor will know who has received AM-101 or the placebo.
Once the initial study is complete, all of the trial participants will have the opportunity to receive the study drug (those given the placebo will be able to receive the actual drug).
The Henry Ford study is seeking patients, ages 18-75, who have been diagnosed within the past three months or less with acute inner ear tinnitus brought on by acoustic trauma, barotrauma, operation on the middle ear, traumatic perforation of the eardrum or middle ear infection.
Those whose tinnitus has existed for more than three months, or was triggered by events other than traumatic cochlear injury or middle ear infection, may not take part in the study.
Participants must agree to use hearing protection, refrain from engaging in activities or work involving loud noise exposure if sufficient hearing protection is not possible, and able to protect ear canal and middle ear from water exposure, as well as be willing to comply with all study-related procedures during the course of the clinical trial.
Patients do NOT qualify for the study if they have/are:
• Pregnant or breastfeeding
• Fluctuating or intermittent tinnitus
• Tinnitus from traumatic head or neck injury
• Suspected of diagnosed Meniere's disease; history of endolymphatic hydrops, or history of fluctuating hearing loss
• History of repeated idiopathic sudden sensorineural hearing loss
• Ongoing, infection of otitis media or otitis externa
• Abnormality of the tympanic membrane in the affected ear(s)
• Hearing loss in the affected ear(s) of 75 dB or more
• Fluctuating hearing
• Any drug-based therapy for otitis media or otitis externa that is ongoing or was performed in the past two weeks
• Any drug-based therapy known as potentially tinnitus-inducing
• Use of any other NMDA receptor antagonist (e.g. memantine, dextromethorphan) in the past two weeks or that is ongoing
• History within the past two years or presence of drug abuse or alcoholism
• Diagnosed as having anxiety disorders, depression, bipolar disorders, schizophrenia or other psychiatric diseases requiring current drug treatment or subjects who required treatment in the previous three months
• Use of any antidepressant or anti-anxiety medication in the past two weeks or that is ongoing
• Any clinically relevant respiratory, cardiovascular, neurological disorder (except vertigo), as determined by the Investigator
• Known hypersensitivity, allergy or intolerance to the study medication o any history of severe drug reaction