Oricula Therapeutics, a Seattle-based biotech, has received FDA clearance to begin volunteer human testing for their investigational drug ORC-13661. ORC-13661 is being studied for its potential to preserve hearing by protecting the ear hair cells of patients taking antibiotics known to cause hearing damage. The human testing will evaluate the safety, tolerability, and the movement (pharmacokinetics) of the drug in the body.
Animal studies of ORC-13661 found highly significant hearing protection in rats exposed to high doses of aminoglycoside antibiotics. Aminoglycosides are a type of antibiotics used to treat bacteria that reproduce quickly or is resistant to other antibiotics. They are a powerful class of drugs which kill the bacteria by disabling the bacteria’s ability to create proteins. Due to the severity of the infections they target, aminoglycosides are often given through an IV, but can also be used orally, as ear drops or as eye drops.
Aminoglycoside antibiotics are known to be ototoxic, which means they may damage hearing. The risk to hearing is well-known and has warranted a boxed warning, sometimes known as a black box warning, from the FDA for these drugs. A boxed warning is the highest warning the FDA can issue on a prescription drug and signifies that using the drug comes with serious risks.
Why Are Ototoxic Drugs Still Prescribed?
Ototoxic drugs are powerful and necessary to treat certain significant infections and illnesses. If a physician determines that the risks associated with taking a drug are less severe than the risks associated with not taking the drug, a patient may be prescribed an ototoxic drug. In those cases, the patient and doctor will decide on a treatment plan.
Aminoglycoside antibiotics are particularly useful for patients with cystic fibrosis, drug-resistant Tuberculosis (TB), and immune suppression. These antibiotics are inexpensive, effective and a useful treatment, in many cases, despite the risk to hearing health.
Can Ototoxicity Be Treated?
Hearing aids are excellent treatment options for people living with drug-related hearing loss. Hearing aids will not reverse hearing loss but will provide an intervention that restores hearing levels to allow for a more connected and engaged life experience.
A hearing aid treats the effects of an ototoxic drug, but the goal of the new, investigational drug is to provide a treatment that prevents the hearing loss in the first place. ORC-13661 has shown evidence, in animal studies, of an ability to protect the hair cells of the inner ear from the damage caused by certain prescription drugs.
Inner ear hair cells are the receptors for the auditory system in humans and all other vertebrates. There are two types of hair cells that, together, are responsible for the amplification and translation of sound vibrations. Ear hair cells do not regenerate, so once they are damaged the associated hearing loss cannot be reversed.
The ORC-13661 clinical trial is significant because there are no FDA-approved drug options for hearing loss caused by ototoxic prescriptions on the market. Clinical trials with humans are just beginning, so it will be years before a true determination of this drug’s function is known.
While this important research continues, hearing aids will continue to be a valuable treatment for hearing loss. If you have questions about your hearing health or about an ototoxic drug that’s been prescribed to you, please make an appointment for a consultation.