Gene therapy companies have faced huge hurdles trying to deliver healthy genes into muscular dystrophy patients’ muscle cells, so here’s an idea: Why don’t we just replace the muscle cells themselves?
Over the last two years, Vita Therapeutics has been exploring that possibility, building on early stem cell work from Johns Hopkins professor Peter Andersen. And on Tuesday they announced a $32 million Series A to begin to move their first therapy into the clinic, where they hope it will help rebuild muscle in patients with a type of dystrophy that afflicts the arms and legs.
The startup is the second portfolio company unveiled by Cambrian Biopharma, the anti-aging portfolio company launched last year by ATAI co-founder Christian Angermayer. (The first was the now public cancer startup, Sensei Bio). Cambrian is taking the approach ATAI took to psychedelic therapies, bringing a broad range of related companies under a single roof, and applying it anti-aging therapies, said CEO and co-founder James Peyer.
They’ve invested in several technologies that could slow or reverse the effects of aging, such as boosting mitochondria or regenerating tissue. But they’re applying them first in diseases where they could have a more immediate impact.
For muscular dystrophies, Vita will try to take the same strategy that CRISPR Therapeutics and other gene editing companies have used for genetic blood disorders such as sickle cell disease. This is not a simple task: Doctors have decades of experience removing and replacing a patient’s blood cells — and over a decade of experience engineering those cells — but it’s not as if you can just extract all of a patient’s muscle cells and then put them back.
Accordingly, companies such as AskBio and Sarepta devised ways of correcting muscle cells in vivo, strapping healthy genes onto (mostly) harmless viruses and administering them to patients as gene therapy. That process, though, has faced a number of hurdles: The genes involved don’t fit well onto the viruses used for gene therapy and the viruses don’t reach all the muscle. Early clinical trials yielded mixed results.
Peyer said Vita doesn’t need to replace all a patient’s muscle cells. Instead, they’ll take stem cells from a patient’s blood, use CRISPR to correct the disease-causing mutations and then manipulate them into a class of cells called myosatellite cells. These cells are responsible for producing mature muscle cells.
Vita believes that they can inject these cells into different parts of the body, where they will produce healthy muscle cells that can replace the damaged ones.
“We have this amazing data in mice that they reintegrate into the muscles,” Peyer told Endpoints News. “And in the mice can improve time on a treadmill or grip strength… It’s really awesome functional outcomes.”
Vita will look to start a clinical trial next year for limb girdle dystrophy, where they will compete with a gene therapy from Sarepta. But even if the therapy works, Peyer acknowledged there will be steep limitations.
For one, it’s not clear how long the cells will last. And although the approach might work to replenish muscle cells in the limbs and lungs, there are no myosatellite cells in the heart and lungs. For many patients with muscular dystrophy, including those with Duchenne, it’s degeneration in these vital muscles that ultimately brings the worst symptoms and death.
“Yeah,” Peyer said, “That’s why we’re not starting immediately DMD.”