Decibel Therapeutics Announces Results of DB-020 Clinical Trial

At the end of June, Decibel Therapeutics announced success in the phase 1b clinical trials on DB-020 for cancer patients receiving cisplatin chemotherapy. DB-020 is a sodium thiosulfate (STS) drug treatment formulated to prevent hearing loss. 

According to a 2009 Tohoku Journal of Experimental Medicine publication, cisplatin is one of the most used chemotherapy drugs in malignant tumors. Commonly it is used in ovarian, testicular, cervical, lung, head and neck, and bladder cancers. Despite the benefits of cisplatin in shrinking tumors and managing cancer, it does have adverse side effects, including ototoxicity, nephrotoxicity, and neurotoxicity.  

According to the American Academy of Audiology, “ototoxicity refers to damage to the hearing and/or balance organs that occurs after exposure to medications or chemicals that affect the inner ear. Ototoxic medications can damage hearing, balance, or both.” 

Since hearing loss is irreversible, the Tohoku Journal of Experimental Medicine article cites it as a dose-limiting factor for cisplatin patients. 

In this study, 17 patients were given 2 doses of DB-020 in one ear while the other ear was given 2 doses of a placebo. Each patient’s experimental results from the DB-020-treated ear were compared to their placebo. The drug and the placebo were administered within 3 hours from the start of cisplatin chemotherapy.  

Of all the patients, 88% experienced ototoxicity in the ear treated with the placebo. Of those who experienced ototoxicity, 87% had minimal or no ototoxicity in their DB-020-treated ear. The average hearing loss was 30 dB from baseline, and patients moved approximately two hearing loss categories. 

Of the 17 trial patients, 13 saw partial or complete ototoxicity protection in the ear treated with DB-020. Full protection, meaning their baseline hearing stayed the same, was found in 8 patients. Additionally, 5 patients experienced partial protection. DB-020-treated ears saw only an 8 dB loss of hearing. 

This study occurred only on a small scale, and additional studies will need to be conducted before this medication can be submitted for FDA approval. However, researchers and medical professionals find the results of this clinical trial promising in mitigating hearing loss risk.   

“We believe these positive data showcase the integrated capabilities that Decibel has implemented to develop innovative therapeutics for conditions of the inner ear. We look forward to reporting additional data from the interim analysis of our ongoing clinical trial of DB-020 at an upcoming medical conference, as we continue to advance our broader pipeline, focused on creating a world of connection for people with hearing and balance disorders,” said Laurence Reid, PhD, Chief Executive Officer of Decibel, in the press release.