A stem cell therapy has helped most patients with Type 1 diabetes live without insulin for at least a year. The results mark one of the biggest advances in decades for the disease.

The treatment, zimislecel, was developed by Vertex Pharmaceuticals. It uses lab-grown islet cells to restore the body’s own insulin production. The Phase 2 data were presented at the American Diabetes Association meeting and published in the New England Journal of Medicine.

Ten of the 12 patients who received the full dose no longer needed insulin injections within six months. The other two cut their doses sharply. One expert called the work “trailblazing” and potentially “life changing.”

Type 1 diabetes affects about 1.4 million Americans. The immune system destroys the insulin-making cells in the pancreas. There is no cure today. Patients depend on lifelong insulin shots or pumps.

The cells are infused into the liver, where they act like natural islet cells. Because the cells come from a lab-grown stem cell line, supply is effectively unlimited.

The trial was small, and it is not yet known how long the effect lasts. Larger trials will decide whether this becomes a real treatment.