Latest Trial Underway for Hearing Restoration Drug FX-322

Frequency Therapeutics is currently conducting a Phase 2b trial to see if a new drug candidate can restore hearing in people who experience sensorineural hearing loss (SNHL). Frequency Therapeutics is the maker of FX-322, which is designed to regenerate hair cells and restore the hearing loss.

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Inside Frequency Therapeutics

According to the company, FX-322 may improve hearing and specifically a patient’s speech perception, the ability to clarify sounds and understand speech, by regenerating sensory hair cells needed to filter and tune sounds. The medication helps small molecules activate progenitor cells to re-grow these lost sensory cells.

To administer the medication, the doctor numbs the ear and injects FX-322 gel into the person’s eardrum. It’s a common procedure that can be performed by an ear, nose and throat (ENT) doctor.

Testing FX-322

There have already been several studies on FX-322. The company says their data marks the first time in human trials that a therapeutic has shown hearing improvements. It appears to be well-tolerated; no serious adverse effects were reported.

“We have conducted five clinical studies of FX-322 to date,” a Frequency Therapeutics spokesperson tells “With each study, we have added to our understanding of FX-322 and the types and severities of hearing loss where individuals may respond to our drug candidate.”

To date, the company has seen improvement in key measures of hearing function (speech perception) in patients who received FX-322 in three separate clinical trials, the spokesperson said. Last year, data from these early human studies was published in Otology & Neurotology

A subsequent phase 2a clinical trial indicated that there was no improvement in hearing loss when comparing the drug to placebo—which the company ultimately attributed to study design issues, including inconsistent baseline measures and study bias that resulted from information being shared regarding inclusion criteria.

Carl Label

Carl LaBel, PhD

In a recent interview with TechCrunch, Carl LeBel, the company’s Chief Development Officer, said “As patients were coming in to the study, there were inconsistencies between their historical speech perception scores and the scores that they were coming into at the baseline visit of the study.”

These insights led Frequency to take a more rigorous approach to the design of its next study, which includes multiple lead-in periods, with both subjects and the trial sites blinded to the study inclusion criteria, as well as building in additional measures to help mitigate potential bias

In the Phase 2b study, which started enrolling last October, the Company plans to enroll 124 patients between the ages of 18 and 65, and is focused on people who have diagnosed noise-induced or sudden sensorineural hearing loss, which is where they’ve seen the greatest response in previous studies, the spokesperson said.

The company anticipates trial results either later this year or early next.

Looking ahead

The company is also looking to test FX-345, which uses a similar approach to FX-322, but could reach more deeply into the cochlea. The company expects to start clinical studies in the latter half of this year, the spokesperson said.

Frequency Therapeutics isn’t the only company working on research in the field of hearing restoration.

“There are other companies working on hearing therapeutics, including work on gene therapy, and regrowing the synapses needed to translate sound signals to the brain,” the spokesperson said. “Our approach is unique in that we are using cells already in the ear to re-start the process of growing new hair cells needed to restore hearing.”

SNHL is the most common form of hearing loss, accounting for about 90 percent of all cases. It can be caused by aging, injuries, drugs, anatomical issues, or exposure to loud noises. It can also be genetic. It occurs when the hair cells or nerve fibers in the inner ear are damaged. Those cells and fibers convert sound vibrations to nerve impulses that then go to the brain. People can be born with SNHL, or it can occur later in life.

As of now, there are no treatments approved by the U.S. Food and Drug Administration (FDA) to repair the sensory system. The FDA has fast-tracked FX-322, so the medicine could be approved sooner than it may normally take.

Previous coverage

In February 2021, HearingTracker interviewed Carl LeBel, the Chief Development Officer at Frequency Therapeutics. Listen to learn more.