For something as pinpoint as a gene, gene therapy can be a blunt tool for treating diseases that affect parts of the body, like the muscle or the heart, that are harder for treatments to reach.
It’s a problem that continues to frustrate researchers and drugmakers, despite the rapid progress the field has made over the past decade.
A two-year-old startup debuting publicly Thursday claims to have the technology to solve it, and has raised $51 million to try. Unusually for a young biotechnology company, the startup, called Kate Therapeutics, already has a deal with a large pharmaceutical firm, also revealing Thursday a licensing agreement with Astellas Pharma.
Kate's claim to an advantage is two-part. The company has at its disposal engineered forms of the viral shells, or capsids, that researchers use to wrap genes for transport into the body, where they are meant to correct a genetic deficit or flaw. Kate also holds technology to adapt the genetic cargo those shells carry so it’s expressed only at the right place.
Kate’s capsids are based on research done by its co-founder and chief scientific officer, Sharif Tabebordbar, and his colleagues at the Broad Institute of MIT and Harvard. Published in Cell in September 2021, their work described a method to generate and select capsids that can target skeletal and cardiac muscle with greater efficiency than others that are now commonly used in gene therapy.
“The goal was to evolve these capsids, starting with AAV9, which is the capsid that companies are using in clinical trials now, and modify them in a way to transduce muscle tissue more effectively,” said Tabebordbar.
Their research, which was noticed by former National Institutes of Health director Francis Collins, could offer a safer way of delivering therapeutic genes into muscle. Existing gene therapies, built around less precise capsids, often end up in the liver and, to compensate, drugmakers use high doses that can cause dangerous side effects.
Astellas has firsthand experience with these concerns, having paused development of a gene therapy for a neuromuscular disease called X-linked myotubular myopathy after the deaths of four boys participating in the company’s trial.
The gene therapy Astellas is licensing from Kate is also aimed at X-linked myotubular myopathy, and drew the pharma’s interest about a year ago, according to Kate CEO Kevin Forrest. A researcher with ties to both companies was impressed by Kate’s preclinical data and encouraged the startup to reach out to Astellas, which saw an opportunity to expand its research around the disease.
“When we saw the data from Kate, it definitely got our attention and we were very keen to have [Kate’s therapy] be part of our program,” Richard Wilson, an executive with Astellas Gene Therapies, wrote in an email. “It is [Kate’s capsid technology] that is the key component to allow us to do something we otherwise would be unable to do.”
Financial terms of the deal were not disclosed, and Wilson did not give a timeline for advancing the therapy into clinical trials. However, he indicated that Astellas would start tests for its manufacturing and for preparing its entry into human testing.
The licensing by Astellas is a sign of the value Kate’s platform can deliver, said Clare Ozawa, a managing director at Versant Ventures, which joined founding investor Westlake Village BioPartners to lead Kate’s Series A round. (Another gene therapy developer, Sarepta Therapeutics, has licensed the capsid technology from the Broad for use in Duchenne muscular dystrophy. Forrest said Kate holds rights from the Broad for specific capsids, and has licensed the broader platform.)
The Series A, along with Astellas’ upfront payment, will fund the rest of Kate’s research, which focuses on two other genetic diseases of the muscle — myotonic dystrophy type 1 and facioscapulohumeral muscular dystrophy, both of which typically develop in older adolescents or adults and are characterized by progressive weakness.
“First-generation gene therapies have focused primarily on younger patient populations and recessive genetic diseases because they are not very potent and use very high doses,” said Forrest, who was a principal at 5AM Ventures before working at two other biotechs. With its capsid and cargo tools, Kate has “the opportunity to go after more difficult-to-treat diseases, adult-onset diseases in heavier and older populations, and dominant genetic diseases.”
The two diseases being targeted are personal to Kate’s leadership: Tabebordbar’s father lives with facioscapulohumeral muscular dystrophy, while co-founder and University of Florida researcher Eric Wang has family members who have myotonic dystrophy.
Their company’s name also has a patient connection: Kate is the name of a young girl in Florida who has a congenital form of myotonic dystrophy.