Overview

• The phase 1/2 zimislecel study moved into phase 3 after 10 of 12 volunteers discontinued insulin therapy one year after receiving stem-cell-derived islet cells.
• Researchers infused human pluripotent stem-cell-derived islet cells that produce self-regulating insulin under an immunosuppressive regimen.
• Participants experienced mild to moderate side effects, including decreased kidney function and reduced immune cell counts linked to the required immunosuppression.
• Two trial volunteers died—one from a post-surgical infection and one from unrelated complications—though neither death was attributed directly to the cell therapy.
• Scientists now face the challenge of securing full FDA approval, addressing high treatment costs and gathering longer-term safety and efficacy data.