Vertex cures ten type 1 diabetes patients using stem cells

Vertex’s new stem cell-based drug may have cured severe type 1 diabetes in 10 of 12 patients in a small trial.

Why it matters: Type 1 diabetes occurs when the immune system destroys insulin-producing islet cells. Patients must carefully manage insulin to survive, a process that’s especially risky for those with hypoglycemic unawareness.

• The drug zimislecel works by infusing lab-grown islet cells derived from stem cells into patients’ livers, where they begin regulating blood sugar levels.

Backstory: The work stems from decades of research by Harvard’s Doug Melton, driven by his children's diagnoses. The first patient treated, Brian Shelton, was cured of diabetes symptoms but died later of unrelated causes.

Behind the trial: One year after treatment, 10 of 12 patients were insulin-free; the rest needed lower doses. All participants had severe hypoglycemia episodes before the study. These episodes stopped after treatment.

Yes, but: The treatment requires lifelong immune suppression, which carries its own risks. Broader applicability and long-term safety remain uncertain.

What’s next: If the study continues to show good results, Vertex expects to submit an application to the FDA as early as next year.