“There are hurdles to overcome in this therapy as well: First, as always, safety concerns. Second, how to deliver the virus carrying the corrective gene into all the regions of the cochlea, that tiny inaccessible spiral. An injection that succeeds in getting only partway into the cochlea would leave the patient with middle- and low-frequency loss. To reach these areas might require opening the cochlea, which would carry a high risk of doing further damage. One further problem is ensuring that the hair cells grow where they are supposed to. Hair cells not at the correct location in the organ of Corti can themselves contribute to profound hearing loss.”
As for the development of prophylactic drugs, the use of “high throughput methods” will help make the time line a little shorter. High throughput methods—also called high content screens—use multiple cell culture dishes testing hundreds or thousands of compounds. Robots may also be used to speed the testing process. This requires work “with big pharma—because we cannot do this in our lab,” Heller said. High throughput screening and the backing of big pharma would increase efficiency, allow the earlier use of screens directly with human cells so they don’t have to go through mice first and then on to humans.