Decibel nets $127M IPO to trial surgical gene therapy delivery

Decibel plans to file to start its first clinical trial of its gene therapy candidate next year. (Nasdaq)

Decibel Therapeutics has netted $127 million from public investors to develop gene therapies that use a surgical delivery method. The IPO haul will enable Decibel to take a gene therapy treatment for a genetic form of profound hearing loss into clinical trials. 

Early gene therapy developers identified the eye as a good proving ground for the modality as it is an enclosed part of the body. The enclosed nature of the eye enables delivery of high concentrations of genetic material to target cells without encountering the safety issues that can arise when large volumes of viral vectors are administered systemically.

Having seen companies including Spark Therapeutics achieve success with ocular gene therapies, Decibel is pursuing a similar approach targeting hearing loss. Like the eye, the inner ear is a small, enclosed part of the body. Decibel plans to use a surgical approach to get gene therapies into the inner ear.

Investors have bought into the idea. Decibel filed paperwork to list on Nasdaq last month, leading to the successful conclusion of the stock offering weeks later. The Boston-based biotech hit the top end of its target share price range and upsized its offering to generate $127 million, after costs. Decibel could pull in more if underwriters take up their options to buy additional shares.

Decibel will use around $40 million of the proceeds to take DB-OTO, a treatment of profound hearing loss due to mutation of the otoferlin gene, through preclinical studies and into the clinic. The gene therapy is delivered via the surgical approach used in a standard cochlear implantation procedure.

Using the existing surgical approach, Decibel thinks it can get high vector concentrations to target cells, potentially increasing transgene expression, while limiting systemic exposure to improve safety and reduce the volume of viral vector needed. In nonhuman primates, Decibel showed “hair cells and other non-sensory support cell types are readily transduced by multiple natural AAV serotypes.”

However, the biotech warned investors it cannot be sure whether the delivery mechanism will be successful, adding that the occurrence of adverse events linked to the procedure could cause clinical trials to be paused or terminated. 

Decibel plans to file to start its first clinical trial of the candidate next year. Prior to that, Decibel will run preclinical studies to generate data to support applications to study the gene therapy in humans.