Is There A Cure For Hearing Loss? | 2021 Hearing Loss Cure Update

Woman seeks cure for hearing loss

After realising they suffer from hearing loss, some patients seek medical help in hopes of fully recovering from hearing-impairment. However, hearing loss is complex because numerous potential causes require different treatment methods. Unfortunately, there is often no known surgery or drug that could cure hearing loss.

Treatment for Different Hearing Loss Types

There are three main types of hearing loss, which require different treatment methods.

1. Conductive Hearing Loss

If you are diagnosed with conductive hearing loss, it means that sound cannot effectively pass through the external auditory canal to the eardrum and the small bones within your ears. It is related to various causes, including ear infections, congenital malformations of the outer or middle ear etc. Surgery (especially for congenital causes) or medication (such as antibiotics for ear infections) are usually used as treatment.

2. Sensorineural Hearing Loss

Also known as nerve-related hearing loss, sensorineural hearing loss is caused by the damage in the inner ear or the nerve that connects the inner ear to the brain. The main causes of this type of hearing loss include head trauma, prolonged exposure to noise, disease, ototoxic drugs (drugs that damage hearing), and ageing. We do not know how to repair or replace inner ear cells once they are damaged. However, immediate medical help can slow down hearing health deterioration.

3. Mixed Hearing Loss

Mixed hearing loss is primarily caused by chronic suppurative otitis media or advanced otosclerosis. This could be treatable, especially with early medical attention. In the later stage, people usually wear hearing aids.

The Ongoing Search for a Hearing Loss Cure

For decades, researchers in labs worldwide have been working to find a cure for hearing loss. In particular, they have been working on a cure for sensorineural hearing loss.

So far, no cure is available, but will there ever be a cure for sensorineural hearing loss?

Perhaps.

There are several ongoing projects which seem promising, and a hearing loss cure could be on the horizon:

Stem Cell Research

Researchers are investigating the potential of having stem cells develop to and function as hair cells. Scientists have discovered the presence of stem cells in the inner ears of mice, chicks, and zebrafish. Stem cells can under the right conditions develop into cells that are remarkably similar to hair cells. Although a cure does not yet exist, the results obtained thus far are promising. Researchers at Stanford Medicine, Rutgers University, MIT, Brigham and Women’s Hospital, and Massachusetts Eye and Ear have all been making progress with research involving stem cells and hearing loss. Besides, scientists at Kyoto University in Japan have conducted research that may help with hearing loss and tinnitus.

Progenitor Cell Activation Research

A biotech company called Frequency Therapeutics is developing an injectable drug called FX-322 to treat sensorineural hearing loss by regenerating hair cells through the activation of cells already present in the cochlea. The working principle is called progenitor cell activation, which is similar to - but not the same as - stem cell research. FX-322 uses progenitor cells to generate inner hair cells and restore hearing ability.

What Is the Progress of FX-322 So Far?

FX-322 has to pass a series of clinical trials to convince the United States Food and Drug Administration (FDA) that it is safe, reliable and effective.

Already, FX-322 has undergone phase 1/2 safety study without any severe adverse events. The data so far showed statistically significant improvement in word recognition scores, although most of the 23 subjects involved did not have measurable impairment in word recognition before the trial.

Besides the word recognition score improvements, three patients had their pure tone thresholds increase by 10-15 dB at 8,000Hz.

On 23 March 2021, Frequency Therapeutics announced data from its Phase 2a clinical trials with 95 participants.

Unlike in the Phase 1/2 study, the subjects in the Phase 2a study had word recognition deficits, which means the data would theoretically give a stronger indication of the efficacy of FX-322.

However, Frequency Therapeutics announced unexpected and disappointing day-90 data: Both the treated and placebo groups saw improvements in word recognition scores. Participants in the placebo group did not actually receive FX-322, so one would not expect to see any improvement in word recognition scores.

So why did both groups have improved scores?

The company proposed two possible explanations.

Firstly, they think there might have been bias introduced by the fact that study participants knew a word recognition deficit was a prerequisite.

Secondly, the Phase 2a study involved four weekly injections, which might have created unfavourable conditions within the ear, although the underlying mechanisms are unknown.

On the bright side, Frequency Therapeutics released some promising data from a separate study. Subjects were injected with a single dose of FX-322 in one ear and placebo in the other ear. 34% of participants saw statistically significant improvements in word recognition scores in the treated ear after 90 days.

What’s Next for FX-322 in 2021 and Beyond?

The end-of-study data from the Phase 2a study will come out late in the second quarter of 2021. However, based on the disappointing day-90 data, Frequency Therapeutics is expected to redesign the trial to reduce bias.

Besides, there will be additional phase 1b data findings coming in Q2 and Q3 of 2021.

If things go well in the revised Phase 2a study, FX-322 could proceed to Phase 3a clinical trials, which will be a larger-scale trial. The data from the third-phase clinical trials will be used to determine whether or not FDA approves FX-322 as the first drug to treat sensorineural hearing loss. This means that there is some promise that we could see our first therapeutic drug to treat hearing loss within this decade. 

The Role of the GFI1 Protein in the Development of New Hearing Hair Cells

Researchers from the University of Maryland School of Medicine (UMSOM) identified the role of a protein in the development of new hearing hair cells. The result shows that in the absence of this protein, called GFI1, embryonic hair cells cannot develop into fully functional adult cells. The genes expressed by these cells are likely to develop into neuron-like cells. They believe that once the complex pathway to normal hearing is found, there is an opportunity to reverse hearing loss.

Other Hearing Loss Treatments

Until a cure for hearing loss is found, it is best to be mindful of maintaining your hearing health and prevent further irreparable hearing loss by seeking help from a hearing care professional. In a hearing consultation, the hearing care professional will evaluate your hearing health and recommend suitable treatment, and they might recommend a hearing aid.

Learn more about different hearing aid types by reading about the Top 6 Most Common Hearing Aid Styles.

Conclusion

As of 2021, there is no cure for sensorineural hearing loss.

There are several projects underway to develop cures for sensorineural hearing loss. Despite disappointing results released in March 2021, Frequency Therapeutics’ FX-322 is perhaps the most promising candidate and could enter Phase 3a clinical trials in 2021 or 2022. If things go well, FX-322 could become available to the public within this decade.

In the meantime, take care of your hearing health and seek treatment if you have hearing loss.

About Incus

Incus has redefined hearing devices by combining the power of traditional hearing aids with the convenience and accessibility of consumer electronics products.

Through continuous hearing technology innovation, Incus empowers people to stay connected with family, friends and the world.

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