Third Rock’s Voyager Hunts For CNS Disorders With Gene Therapy
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proprietary in-house library of AAV’s that the company could either use to develop its own gene therapies for rare neurological disorders, or to form licensing deals with pharmaceutical companies for diseases it isn’t interested in working on, according to Levin.
“We’re going to be taking pieces from each one of the viruses and even changing pieces of the virus and create a whole new estate of intellectual property,” he says.
Still, Voyager is facing some big challenges. The company plans to deliver these therapies by injecting them either into the spine, or directly into the brain, depending on the disease it’s targeting. And despite the early indications that AAV’s generally don’t trigger an immune reaction, there’s always the risk. That’s something Levin says the company will pay very close attention to.
“The delivery systems are important, they have to be safe,” Levin says. “There are different technologies and different approaches for all of these, but they’re doable.”
To get a product through clinical trials and to FDA approval, Voyager will have to break new ground. There are no FDA approved gene therapies, and there’s only one approved in Europe. An AAV gene therapy San Diego-based Ceregene had been developing for Parkinson’s, for instance, failed in Phase II clinical trials last year. Richmond, CA-based Sangamo Biosciences (NASDAQ: SGMO) has since acquired Ceregene, and with it, a mid-stage gene therapy program for Alzheimer’s Disease.
Initially, Voyager has three programs in mind: Friedreich’s Ataxia, ALS, and Parkinson’s. Freidreich’s is characterized by genetic mutations that limit the production of frataxin. Voyager’s plan is to inject an AAV into a patient that would deliver frataxin into the body over a long period of time. For ALS, Voyager would inject an AAV with a micro RNA molecule that would knock down a gene called SOD1 that is known to mutate in patients with the disease.
Parkinson’s, meanwhile, is a bit of an outlier program for Voyager in that the company is not looking to address an underlying genetic mutation. Instead, Voyager would use an engineered virus containing an enzyme known as AADC through a shot directly to the putamen, a part of the brain. That enzyme helps the brain convert levodopa into dopamine, which scientists hope will quell the symptoms of Parkinson’s. Bankiewicz is running a Phase 1b clinical trial testing this method in human patients. The idea is that this would provide a long-term relief, rather than require a bunch of repeat shots, though the extent of the therapy’s effect hasn’t really been proven in humans yet.
“It’s not a cure for the disease, but it’s a real dramatic increase in the quality of life, we believe,” Levin says.
Voyager isn’t the only company trying such an approach in Parkinson’s. Netherlands-based Uniqure (NASDAQ: QURE) and UK-based Oxford BioMedica are developing different gene therapies for Parkinson’s, and Uniqure cut a deal with Bankiewicz in 2012 to test its gene therapy in an early study. That deal is independent of what Voyager is doing, Levin says. The trial is ongoing, according to regulatory filings.
Even with the specter of competition, Bankiewicz’s study represents Voyager’s most advanced program. If that study goes well, Voyager would then optimize the AAV vector he’s using and potentially use a souped-up version of it in a bigger trial late next year. The company is still designing the viral vectors that it wants to use to treat Friedrich’s Ataxia and ALS, and expects to finish those and begin trials in a couple years. Those are just a few of the AAV’s the company wants to have in the library it’s putting together.
“This has not really been done at this scale before, so we really need to do this carefully and with a lot of thought,” Levin says. “When you think of the future of proteins and large molecules and delivery to different parts of the brain, the AAV virus really becomes a key product engine to do that.”