What just happened? The dream of a cure for type 1 diabetes may have taken a step closer after a man with the disease received a transplant of genetically altered pancreatic cells that allowed his body to produce its own insulin. The important factor here is that the patient did not require the usual immunosuppressant anti-rejection drugs, which are normally taken for life and can have extreme effects.
In December 2024, a 42-year-old Swedish man with type 1 diabetes received 17 injections of donated islet cells. They had been genetically modified via CRISPR to avoid the need for immunosuppressive medicine.
Islet transplantation for the treatment of type 1 diabetes – an autoimmune condition where the body attacks pancreatic cells that make insulin for an unknown reason, thereby requiring administration of synthetic insulin – has been around for two decades, though it was only approved in the US in 2023. But in addition to the supply of donated beta cells being low, patients must take anti-rejection drugs for life, the effects of which are often considered worse than living with well-controlled type 1.
Scientists have been looking for a way to transplant islet cells that provide a constant supply of insulin for type 1 diabetics, and without the need for permanent post-op drugs, which would be the closest thing to a cure.
Researchers at Sana Biotechnology used the CRISPR genome editor to eliminate the HLA-I and HLA-II antigens, which can prompt an immune rejection, from the donated beta cells. The cells were also engineered to produce more of the CD47 protein that signals to immune cells to prevent attacks by the immune system.
After tests were carried out on rodents and a monkey, researchers injected the cells into the forearm of the man, who has had type 1 diabetes since 1987. While the immune system did kill the unedited donor cells, the fully edited beta cells survived – without immunosuppressants – and were manufacturing insulin three months after the procedure.
It's important to note that the man still needs to take insulin to keep his blood sugar in range; Per-Ola Carlsson of Uppsala University said, "We transplanted 7% of a curing dose." But the test marks a major step toward a cure that many with type 1 diabetes have been told would arrive "within the next decade" since the 1970s.
The patient will now be monitored for 15 years, as required by EU regulations. Sana's next step is to genetically engineer beta cells grown from stem cells in culture, enabling a far greater supply than relying solely on donor cells.