Volume turns up on Decibel as hearing loss therapy protects patients in early-stage trial

A small data set but big improvement in the hearing loss brought on by chemotherapy was enough to send Decibel Therapeutics' shares soaring in premarket trading Tuesday.

The Boston-based biotech has found that DB-020 protected patients from hearing loss caused by the chemotherapy cisplatin, a condition known as ototoxicity and one that can be permanent. In the phase 1b trial, 19 patients who had not previously received cisplatin were treated in one ear and received a placebo in the other. The interim results include 17 evaluable patients.

The news sent Decibel’s shares up 31% in early morning trading, to $2.95 compared to a prior close of $2.24. Additional results from the trial will be presented at an upcoming medical conference.

The interim data released today showed that 88% of patients experienced hearing loss in their placebo-treated ear. But for the ears treated with Decibel’s therapy in this same group of patients, 87% were partially or completely protected from ototoxicity. Safety and tolerability data were similar to a previous study of healthy volunteers, with generally mild to moderate adverse events.

Decibel Chief Development Officer John Lee said the data support the advancement of DB-020 to prevent or minimize this type of hearing loss. The therapy can be delivered to the ear and is a formulation of sodium thiosulfate, which has medical uses including as an antidote for cyanide poisoning. 

Decibel launched in 2015 to tackle hearing loss, with DB-020 and a clutch of gene therapies for different indications in development. DB-020 is the furthest along, but the gene therapy DB-OTO is being prepped for human testing and is aiming to treat patients with hearing loss caused by a mutation of the OTOF gene. The therapy is being developed with Regeneron.