Ready for some progress in the search for a cure for hearing loss? Yeah, me too.
I came across an article on how researchers recently used a drug-like cocktail to regenerate hair cells for hearing loss. The findings were published in an April 2023 study in the scientific journal PNAS.
Sounds promising. But as a layperson, it can be hard to understand what that means, and if it’s actual progress.
So I reached out to the study’s principal investigator, Zheng-Yi Chen, DPhil, an associate scientist in the Eaton-Peabody Labs at Mass Eye and Ear in Boston. Dr. Chen graciously replied to my questions about his findings.
In a nutshell, this study is the first of its kind to show that drugs may one day be able to be used to regenerate hair cells in a clinical setting (i.e. a doctor’s office) — and some of the existing tools researchers already have may help to speed up development. In the future, the drug cocktail may be used to treat noise-induced or age-related hearing loss, or in combination with gene therapy to restore hearing in people with genetic hearing loss.
1. How are your findings different from previous research on potential treatments for hearing loss?
In the previous study, we showed that it is possible to regenerate hair cells in the fully mature mammalian inner ear by genetic manipulation. The current study is to demonstrate that similar hair cell regeneration can be achieved by a combination of drug-like molecules, which is a major step for us to move the work towards the clinic.
This is not to say we have solved all the issues. We now focus on using the new approach to restore hearing in deaf mice, and all the information will be necessary for future clinical development.
2. What most surprised or excited you about the findings in this study?
The most surprising part is that some of the molecules we use to regenerate hair cells have been used in patients (VPA, LiCl) or the technology is mature (for siRNA in humans including Alnylam’s drugs), so we may benefit from the mature technology to speed up our work toward the clinic.
3. What are you hoping these findings will lead to in terms of potential genetic therapies for hearing loss?
If hair cell regeneration ultimately results in the treatment of hearing loss in patients, it potentially could be applied to the largest patient population with hearing loss including people suffering from age-related and noise induced hearing loss.
For genetic hearing loss, while regeneration alone may not be sufficient, it can be combined with gene therapy that is progressing rapidly as treatment. For many forms of genetic hearing loss due to hair cell damage or loss, gene therapy alone will not be sufficient due to the loss of a large number of hair cells. In this situation, we can regenerate hair cells and perform gene therapy at the same time as the treatment. The gene therapy approach is part of the hair cell regeneration in our study in which Atoh1 is delivered by adenovirus.
4. How can people with hearing loss help support hearing loss research like the type you’re doing?
There are many ways for people with hearing loss to support and speed up our work. Patients should first be properly diagonalized so we know what type of hearing loss they have (e.g. genetic, noise-induced, viral infection or age-related). This will serve as an important resource for potential candidates for future clinical trials.
Patients could join different organizations (e.g. the Hearing Loss Association of America) to help themselves and other people with hearing loss.
Of course, making donations is one of the most effective ways to help our work. I cannot emphasize enough how philanthropic support has helped our work enormously and will continue the trajectory till we develop the treatment.
We are truly excited about the future and will do all we can to get there as soon as we can.