An international team of surgeons and scientists has, for the first time, validated safe surgical access to the central core of the human cochlea in a study funded by Rinri Therapeutics, a biotechnology company developing regenerative cell therapies for sensorineural hearing loss (SNHL). The research is published in Scientific Reports.

The team from Guy’s and St Thomas’ NHS Foundation Trust in London and the universities of Uppsala (Sweden), Sheffield (UK), Nottingham (UK) and Western University (Canada) has proven and confirmed a secure clinical pathway to the inner ear, which will enable the application of a range of regenerative therapies to restore hearing.

The human cochlea lies in the base of the skull, encased by the hardest bone in the human body. This has hampered the progress of discovering new treatments for hearing loss. Using a detailed representation of the microanatomy of the peripheral auditory neural structure, surgeons have now been able to reach the human cochlea safely with a routine surgical approach.

Marcelo Rivolta, Professor of Sensory Stem Cell Biology at the University of Sheffield and Founder of Rinri Therapeutics said: “Until now this region of the inner ear has been inaccessible in humans. This means that the pioneering advanced therapies to repair the auditory nerve, which have already proved successful in animal models, have been hampered by limited anatomical knowledge and the lack of a safe access to Rosenthal’s canal – the compartment that houses the auditory neurons within the central core of the cochlea.

“We believe these findings will have immediate impact on both our understanding of the microstructure of the inner ear and the first in-human trials of new gene and drug therapies to improve hearing loss and deafness.”

Professor Helge Rask-Anderson from Uppsala University said: “We are pleased to be a part of this exciting project with our international colleagues that may form a ground pillar for clinical trials.”

Gerry O’Donoghue, Professor of Otology and Neurotology at the University of Nottingham and Clinical Advisor to Rinri Therapeutics, said: “The inaccessibility of the human cochlea has hampered the progress of curative treatments for SNHL to date. These findings however will enable the safe delivery of regenerative therapeutics to their target structures within the relatively impenetrable human cochlea, de-risking future clinical interventions and paving the way for clinical trials.”

In the recent Inner Ear Therapeutics issue of ENT & Audiology News, Profs Rask-Andersen and O’Donoghue discussed topics including regenerative therapy, auditory nerve cell cultures and synchrotron technology.