EU-funded research breakthrough offers hope to millions with hearing impairments

European researchers have developed a new drug that could transform the lives of people with hearing impairments, and tap into a significant market.

Potential beneficiaries of this breakthrough from the EU-funded AFHELO project include people exposed to noise – in particular through accidents, hazardous working conditions or exposure to military operations – along with Europe’s growing elderly population who face age-related hearing impairments. Approximately 10 % of the global population (40 % of people over 65), suffer from hearing difficulties.

‘The AFHELO project was launched to determine if AF243 compound (a cholesterol derivative) could be used as a preventive and curative drug for hearing loss,’ explains Stéphane Silvente, President of French technology firm Affichem which coordinated the project. ‘Recent studies – such as the EU-funded EUROHEAR project – demonstrated that this compound could help maintain and restore auditory nerve functionality, and thus improve the effectiveness of cochlear implants.’

The project could also have long term socio-economic consequences. Early hearing impairment in children can affect language learning and lead to behavioural issues, while in adults, hearing difficulties can impair social integration.

Preclinical studies carried out by the project team confirmed the neurotrophic and neuroprotective properties of AF243, along with its ability to restore the functionality of auditory nerves and prevent noise-induced hearing loss. ‘It is worth noting that AF243 is easy to produce and safe,’ adds Silvente. ‘Altogether, our results strongly support the conclusion that AF243 can help prevent and treat hearing loss.’

The AFHELO project will be completed in mid-2016, and work will continue to ensure that the potential of AF243 is fully exploited. The next step will be to validate the efficacy of the drug in larger cohorts of animals and in parallel develop a local delivery approach. This will then be followed by regulatory studies, which is a prerequisite before human trials can begin. ‘The first evaluations in humans should take place in a couple of years,’ says Silvente. ‘We will continue to involve patients’ associations and regulatory agencies.’

Another goal of this project was to obtain a better understanding of the causes of the early onset of hearing loss. Good hearing depends on the integrity of the sensory epithelia in the inner ear, while hearing impairment occurs when sensory hair cells die and spiral ganglion neurons degenerate. To date, there is no potent curative or preventive solution for hearing impairment, with clinical options limited to the use of prostheses such as cochlear implants.

Since these hair cells and spiral ganglion neurons develop from the same origin, the team saw that the growth factors that affect their differentiation could present a potential target for therapeutic applications. The AFHELO project therefore focused on the effects of AF243 on cell differentiation and neuron survival, and found that the compound was highly effective. The team also found that folic acid deficiency resulted in premature hearing loss, showing that bad eating habits can have an impact on hearing.