Third Rock, SR One Put $52M Into Decibel to Battle Hearing Loss

Xconomy Boston — 

People can lose their hearing for a variety of reasons, from age to loud noises, but there’s one thing they all have in common. There are no drugs to help them. Several companies have formed in recent years to address this gap, and now there’s another coming to the party a bit late, but with deep pockets—a new startup called Decibel Therapeutics, which is embarking on a broad effort to figure out what makes us go deaf in the first place.

Boston-based Decibel is officially launching today with a $52 million Series A round from two venture firms: Third Rock Ventures, and SR One, the VC arm of GlaxoSmithKline. The two firms have assembled a group of scientific experts in hearing disorders to understand the underlying biological reasons for a variety of hearing issues, and develop drugs to combat them.

Third Rock tends to do large Series A rounds like these on its own. But Decibel CEO and Third Rock partner Kevin Starr says in this case, the firm and SR One were talking to the same people. Rather than compete, they teamed up, though Third Rock is providing a majority of the cash—around $46 million, he says.

According to Harvard Medical School otology professor M. Charles Liberman, one of Decibel’s scientific founders, Decibel will focus “very broadly” on what’s known as sensorineural hearing loss (SNHL), which is associated with problems in the inner ear. These problems can happen for a variety of reasons, from extremely loud noises to aging, and they’re widespread. According to the Hearing Health Foundation, nearly 50 million Americans and 360 million worldwide have hearing loss. Hearing aids and cochlear implants are effective in some cases, but they don’t work for everyone.

Decibel is based on the work of four scientists: Liberman, fellow Harvard professor Albert Edge, University of Michigan professor and Kresge Hearing Institute director Gabriel Corfas; and The Scripps Research Institute’s chair of neuroscience, Ulrich Mueller. They’ve generated new insights over the past few years into the workings of the inner ear and a possible way to repair damage.

Liberman describes SNHL, for instance, as a connection problem between two key actors in the inner ear: sensory cells, which turn vibrations into electrical signals; and nerve fibers that take those signals to the brain. Think of sensory cells as a microphone, and the nerve fibers as a cable. We are born with a finite number of each. Synapses connect the two, and essentially turn on the microphone.  “The connections between the microphone and the cable are broken [in hearing loss],” he says. “All we’re doing is fixing the connector.”

Recent mouse studies Liberman and Corfas have conducted, for instance, have shown that overexpressing a certain protein—neurotrophins, which help neurons survive—might help repair those synapses.

“Some of that stuff has a nearer term horizon, and some of that stuff has a longer term horizon,” Liberman says. “But Decibel wants to be in it for the long haul.”

Starr says the company will start with tiny patient groups: kids with cystic fibrosis or cancer who can lose their hearing because of treatment with antibiotics (aminoglycosides, for the infections CF patients get) or chemotherapy (for cancer patients). With success Decibel will move to more prevalent problems, like a consistent ringing in the ears called tinnitus, or age-related hearing loss, both of which affect millions across the globe.

Decibel isn’t disclosing its first drug program except to say it’s an antibody meant to help grow neurites, the projections from the body of a neuron, like an axon or dendrite. It’ll be injected directly into the inner ear, Starr says. So a cancer patient would get an injection of a Decibel drug before chemo; a CF patient, before the antibiotic.

Decibel is well behind an emerging field of companies that have already sprouted up, like Otonomy (NASDAQ: OTIC), Auris Medical (NASDAQ: EARS), Autifony Therapeutics, and Audion Therapeutics.

Otonomy has a drug on the verge of late-stage trials for Meniere’s disease, a fluid imbalance of the inner ear that can cause gradual hearing loss. Auris Medical has one in Phase 3 trials for tinnitus. And Autifony is a GlaxoSmithKline spinout—meaning Decibel isn’t its first foray into hearing loss. (Check out this detailed piece from Chemical & Engineering News for a broad look at the field).

Starr says that the big difference between Decibel and many of these competitors is its breadth. “Many of those companies are single product shots,” he says. “This’ll be by far the largest effort in building the fundamental platform of understanding what’s happening physiologically, in hearing, in the world.”

Whether that investment will lead to effective drugs remains to be seen, but Decibel hopes to have its first in human clinical testing in less than three years. The eight-employee company should grow to 50 or 60 over the next year or two. Liberman is thrilled to see it all play out.

“I’m incredibly excited that after 40 years at the bench doing basic science it looks like some of our ideas are going to be taken from bench to bedside,” he says.