After years of failure, ViaCyte shows off first proof-of-concept for diabetes stem cell transplants
Seven years after they first tried it, ViaCyte finally has data showing that their stem cell treatment for diabetes — a potential cure — can work in a patient.
The data are extremely limited: They come from a single patient. But they provide, outside experts say, the first proof-of-concept for an approach that companies, including Vertex, and diabetes research foundations are betting could eventually provide a functional cure for many patients with type 1 diabetes and — down the road — the millions more with type 2 diabetes.
The limited results were particularly noteworthy because ViaCyte’s first attempt at transplanting lab-grown, insulin-producing into patients beginning in 2014 had been a failure.
“It’s actually very impressive — I was not impressed by their first trial, but this is a major improvement,” Camillo Ricordi, director of the Diabetes Research Institute at the University of Miami, told Endpoints News. “It’s a critical first step, it shows that they can work.”
At the same time, the results fell short of Viacyte’s ambitions to create a functional cure. Despite the new cells, the patient still needed to take insulin to control her disease.
“I would think it’s not having enough of an effect,” Jeanne Loring, a professor emeritus at Scripps Research, told Endpoints.
Loring, who launched a forerunner of Viacyte in 1998 and maintains a modicum of stock, said the results were good but unsurprising. “With any of these cell replacement therapies, the wish is to have a complete cure,” she added, “but at least until they get better, it is likely to just reduce the need for insulin.”
The procedure, first conceived decades ago, involves taking a bank of stem cells, manipulating them to become pancreatic precursor cells and then implanting them into a patient. There, they develop into insulin-producing beta cells, replacing the ones that are lost in type 1 diabetes patients.
The approach was meant as a scalable alternative to islet cell transplant, an operation that has treated thousands of patients, many of who were able to go off insulin, but whose reach is limited by the limited number of available donors.
That was easier said than done, though. When ViaCyte first put their cells into humans in 2014, encapsulated in a device meant to shield the lab-grown cells from the patient’s immune system, most of the cells didn’t engraft. The patients saw little, if any, change to their disease. The device “obviously did not work,” Ricordi said.
Reeling from the failure and facing new competition from a startup out of Harvard called Semma, ViaCyte tried an easier approach. They implanted the cells in a porous device that allows blood vessels to reach through. That means the cells are exposed to the immune system and patients have to take immunosuppressants — limiting the therapy to only the sickest 10% of diabetics — but it also allows the cells to fully engraft.
Nine months after undergoing therapy, the patient in the study, a woman who had diabetes for 36 years and was considered “brittle,” had multiple indicators of high levels of insulin production. C-Peptide, a biomarker of insulin, had increased from 0.1 nanogram per mililiter, to 0.8.
Her HbA1C, a measure of blood sugar control, dropped from 7.4% to 6.6%, putting her almost below diabetic levels. She went from having her blood sugar in a healthy range 54% of the time to 84% of the time.
“This case is seminal,” CEO Michael Yang told Endpoints. “It’s really the first time that it’s ever been shown that an implanted set of cells in a patient can produce glucose responses, insulin and impact clinical measures in a meaningful way.”
Still the data fall well short of what Yang says is the ultimate goal: a cure, effectively an artificial pancreas. It’s just one patient — a result, in part, of the pandemic shuttering enrollment in their study — and that patient remains on insulin. And at best, Yang said, the treatment will work for 2 to 5 years.
Yang said they have more patients ready to enroll soon and, after finishing a 10-12 person study, will talk to the FDA about launching a pivotal trial. But they are now in a close competition with Vertex, who spent $900 million to buy Semma in 2019, and was cleared earlier this year to launch their own trial.
Although both now rely on immunosuppresants, they are each developing new approaches to shield the cells from the immune system, which would open the treatment to far more patients. Other companies, Ricordi noted, are also developing safer and more tolerable alternatives to immunosuppresants that could be used in tandem with the stem cell therapies.
With more resources, Vertex could beat ViaCyte to market — a product, in part, of their decision to start with the failed encapsulation device in 2014. But Yang, who joined the company earlier this year, said he doesn’t have regrets.
“I’m a front windshield kind of guy,” he said. “So the fact that we have this data, I’m looking forward to seeing what we can do.”