Regeneron is aiming to file a regulatory application for DB-OTO by the end of the year.
Regeneron is clearing a regulatory path for its investigational gene therapy DB-OTO after an early phase study demonstrated hearing improvements in children with a genetic form of deafness.
The data, presented Sunday, showed that 11 of 12 patients in the Phase I/II CHORD study experienced “clinically meaningful” improvements in hearing, according to the pharma, with treatment response becoming apparent “within weeks” of administration. Three children were able to reach normal levels of hearing at the time of the readout. Upon longer follow-up, eight other patients experienced stability of hearing or saw continued auditory improvements.
These data were concurrently published in The New England Journal of Medicine.
In a note to investors on Sunday, analysts at Leerink Partners called these findings “compelling,” adding that they indicate DB-OTO’s ability to “transform patients’ lives.” The data will support a regulatory application with the FDA, with Regeneron planning a submission by the end of the year.
While Regeneron’s results are promising, Leerink on Sunday nevertheless cautioned that DB-OTO’s “commercial opportunity could be limited to young patients who have not yet had cochlear implants.” Adding to this, the analysts also noted that Regeneron “could face competitive product introductions in the future” from other companies working on congenital hearing loss.
Designed to be delivered via an infusion in the ear, DB-OTO is an adeno-associated virus-based gene therapy that delivers a functioning copy of the OTOF gene, which when mutated leads to congenital hearing loss. This specific type of genetic deafness is an ultra-rare condition that affects around 20 to 50 infants in the U.S. per year, and for which there is currently no cure.
CHORD is ongoing and has a target enrollment of 30 patients carrying the OTOF mutation, who qualify as having “profound” hearing loss, defined as being unable to hear a gas-powered lawn mower, as described in the NEJM paper. On Sunday, Regeneron additionally revealed that after DB-OTO treatment, nine patients reached hearing levels that would typically no longer require cochlear implants. Six children were able to hear soft speech unassisted, while three were even able to pick up on whispers.
As for safety, Regeneron reported two serious adverse events, one of which was due to a complication of a cochlear implant surgery, while the other was linked to a recent vaccination. Aside from these, the pharma noted that DB-OTO and its associated surgical procedure were well-tolerated. Common adverse events included nausea and vomiting.
A competitor developing in parallel is Eli Lilly subsidiary Akouos, which was acquired for $487 million in October 2022. Just over a year later, in January 2024, Lilly reported that Akouos’ gene therapy AK-OTOF was able to restore the hearing of an 11-year-old boy within 30 days. As in the case of Regeneron’s CHORD study, this child had profound hearing loss from birth due to otoferlin mutations. The asset is currently in Phase I/II development with a completion date of October 2028.
