Regeneron's Hearing Loss Gene Therapy Shows Promise, Paving Way for FDA Submission

Regeneron Pharmaceuticals is poised to seek FDA approval for a groundbreaking gene therapy targeting a rare, genetic form of deafness, following encouraging results from a small clinical trial. The therapy, code-named DB-OTO, has demonstrated significant improvements in hearing for children with a specific gene mutation, potentially offering an alternative to cochlear implants.

Trial Results Demonstrate Efficacy Across Age Groups

The study, results of which were published in The New England Journal of Medicine, involved 12 children ranging from 10 months to driving age. After six months of treatment, nine participants achieved the study's primary goal, demonstrating hearing in the moderate to normal range.

Contrary to prevailing views, the therapy showed benefits across various age groups. Lawrence Lustig, a trial investigator and hearing specialist at Columbia University Medical Center, described the results as "game-changing," noting that some children returned to "essentially normal hearing."

One particularly notable case involved a 10-month-old participant who, by the 24-week mark, had improved to normal hearing levels. At 96 weeks post-treatment, this child scored 70% on a single-syllable word test, showcasing sustained improvement over time.

Technical Aspects and Administration

DB-OTO utilizes disarmed viruses to deliver functional copies of the malfunctioning gene directly into the inner ear. The therapy is administered via the same surgical approach used for cochlear implants, a design choice aimed at ensuring surgeon familiarity and comfort with the delivery method.

Importantly, the natural barrier separating the cochlea from the bloodstream appears to prevent interference from neutralizing antibodies, a common challenge in gene therapy. This feature potentially broadens the therapy's applicability, as 10 participants who tested positive for these antibodies still experienced therapeutic benefits.

Safety Profile and Future Considerations

The treatment has demonstrated a generally favorable safety profile, with most adverse events being minor and short-lived. However, two serious events were reported: one participant experienced walking instability, and another developed a severe bacterial infection in an untreated ear. Both issues resolved without long-term complications.

As Regeneron prepares to submit an approval filing to the FDA by year-end, questions remain about the therapy's long-term efficacy and potential need for re-dosing. The company views the apparent benefits as justifying what is likely to be a high cost, with Jonathan Whitton, Regeneron's global program head for hearing research, emphasizing the immense value of hearing in connecting individuals to their environment and families.