Zimislecel Stem Cell-Derived Islet Therapy Restores Insulin Independence in 83% of Type 1 Diabetes Patients in NEJM Phase 1-2 Trial
View StudyPlain-Language Summary
A phase 1-2 study published in the New England Journal of Medicine found that zimislecel, an allogeneic stem cell-derived islet therapy, restored insulin-producing function in all 14 participants with type 1 diabetes who completed at least one year of follow-up. Among the 12 participants who received the full dose, 83% achieved insulin independence at one year. These results mark a major milestone in the pursuit of a functional cure for type 1 diabetes through cell replacement therapy.
Abstract
Type 1 diabetes is caused by autoimmune destruction of pancreatic beta cells, requiring lifelong insulin therapy. Islet transplantation can restore beta cell function and glucose regulation but is constrained by organ donor scarcity and the need for ongoing immunosuppression. Zimislecel (formerly VX-880) is an allogeneic, stem cell-derived, fully differentiated islet cell therapy developed by Vertex Pharmaceuticals, designed to provide an unlimited source of functional beta cells without reliance on donor organs.
This phase 1-2 open-label study (ClinicalTrials.gov NCT04786262) enrolled adults with type 1 diabetes who had impaired hypoglycemia awareness or a history of severe hypoglycemic events. Part A enrolled 2 participants who received a half dose (0.4 x 10 to the ninth cells), while parts B and C enrolled 12 participants who each received a single full dose (0.8 x 10 to the ninth cells) via portal vein infusion. All participants received glucocorticoid-free immunosuppressive therapy. A total of 14 participants completed at least 12 months of follow-up and were included in the primary analyses.
C-peptide, a marker of endogenous insulin production, was undetectable at baseline in all 14 participants. After zimislecel infusion, all participants demonstrated engraftment and glucose-responsive islet function as evidenced by detectable C-peptide. Among the 12 full-dose participants, 10 (83%) achieved insulin independence at one year, with all meeting targets for HbA1c below 7% and time in glucose range above 70% without severe hypoglycemic events from day 90 through 12 months. Neutropenia was the most common serious adverse event, occurring in 3 participants. Two deaths occurred during the study period, both from causes unrelated to zimislecel treatment. The authors concluded that these results support the hypothesis that zimislecel can restore physiologic islet function and warrant continued investigation in phase 3 trials.