The rapid maturation of gene therapy technologies has galvanized a wide range of projects throughout industry and academia, and now a team of researchers from Harvard and Boston Children's Hospital believe they may have come up with a one-time treatment for a genetic cause of deafness.
The scientists homed in on TMC1, a gene tied to hair growth in the ear and thus the body's ability to turn sound vibrations into neuro signals. Mutations to TMC1 lead to hearing loss, accounting for between 4% and 8% of genetic deafness, and the researchers figured they might be able to reverse the effect by crafting a therapy that inserts a replaces the defective gene with a corrective copy.
In a study published in Science Translational Medicine this week, the team tried out its gene therapy on newborn mice with TMC1-related deafness, testing how much they jumped in response to loud noises. And the method worked, as the mice displayed not only "acoustic startle reflexes" but measurable brain activity confirming they could hear.
The therapy did not completely restore their hearing, however, and Harvard's Jeffrey Holt, a co-author of the study, told NPR the treatment will need some tweaking before it's ready for further study.
But the preclinical advance heralds some hope for a condition with no pharmacological solutions available and underscores the promise of gene therapy for inherited disorders.
The field is by no means new, but years of safety concerns hampered advancements and discouraged investors until more recent discoveries led to the development of safe, predictable delivery mechanisms for corrective genes. That, coupled with the increasing sophistication and affordability of genomic sequencing, has opened up thousands of treatment avenues for scientists looking to fix monogenic disorders.
Novartis ($NVS), under a $214 million partnership with GenVec, is developing a gene therapy for deafness of its own, working through a Phase I/II trial targeting the gene Atoh1, which, when mutated, can destroy hearing.