The World Health Organisation (WHO) has put together some key facts regarding hearing loss, and its statistics.  

• By 2050 nearly 2.5 billion people are projected to have some degree of hearing loss and at least 700 million will require hearing rehabilitation.
• Over 1 billion young adults are at risk of permanent, avoidable hearing loss due to unsafe listening practices.
• An annual additional investment of less than US $1.40 per person is needed to scale up ear and hearing care services globally.
• Over a 10-year period, this promises a return of nearly US $16 for every US dollar invested.

From these figures there is research worldwide regarding hearing loss generally but Professor Marcelo Revolt of Rinri Therapeutics has shared information about his research into “Hearing Loss and Stem Cell Therapy”.

Researchers at Rinri Therapeutics are dedicated to study the biology and behaviour of auditory stem cells (primarily human) and to explore their potential to regenerate the damaged inner ear.

Rinri Therapeutics was founded in 2018 by Marcelo Rivolta, Professor of Sensory Stem Cell Biology at the University of Sheffield (UK). The company receives senior leadership and strategic direction from a number of clinical key opinion leaders who are frontline clinicians, passionate about improving outcomes for hearing loss patients across the spectrum of hearing conditions.

The Professor has been working on a therapy for hearing loss for 25 years. Specifically on Stem Cell Therapy since the early ‘00s. In 2018 he felt he had a good enough evidential base with which to make the leap.

Originally from Argentina he moved to the US to do a fellowship at the National Institute for Deafness and Communication Disorders, NIH.

The Professor said: “I find the hearing organ fascinating: it’s so complex, and the way that it’s developed, that it’s arranged, is just a marvel of biology. That was the initial scientific attraction”.

He said for the last 40 years, the only options available to patients have been prosthetic devices: cochlear implants and hearing aids. They have been great, but they are not the real thing and there is currently no biological treatment or cure for the condition.

The clinical trials and strategy

The aim is to get Rinri to a point where they can replicate in the human patient what they have been developing in the animal trials. There are two key cell types in the ear which can get affected and produce deafness: One is the hair cell, which converts sound into an electrical signal, and the other is the neuron, which is the cable that connects the hair cell to the brain.

These are the two cell types which are really important in the cochlea, and when they are damaged, they cannot be restored. They don’t regenerate. So those are the cells that in principle they are trying to replace using stem cells.

Their current focus is the neuron – the cable that connects the hair cell to the brain. This is for a number of reasons, one of them being the fact that when we lose hair cells, we have cochlear implants that can replace them, but they still need the nerve to connect to the brain. So, their first therapy is focused on replacing the neurons. They are working on replacing the hair cells but that will be further into the future.

The idea is to make the cells in the test tube and then to apply them to patients, either for them to reconnect with the hair cells, or to interact with the cochlear implant.

So at a very high level, that will be the basis of the clinical trials.

Is stem cell therapy a potential cure for hearing loss?
https://www.labiotech.eu/in-depth/stem-cell-therapy-hearing-disorders