Vertex Pharmaceuticals announced in a press release on Friday, March 28, 2025, that its VX-264 clinical trial using manufactured insulin-producing cells protected by the immune system with a surgically implanted device failed to produce significant results. The trial has ended.
VX-264: While VX-264 proved to be safe, c-peptide levels (which indicate insulin production) were not significant. The trial will not continue.
VX-880: VX-880 forges ahead with an official name: Zimislecel. While using Vertex’s cell-based therapy to produce insulin in people with type 1 diabetes, VX-880 relies on immunosuppression. It is intended for people who experience frequent and severe hypoglycemic events.
As of December 2024, 11 out of 12 participants in the VX-880 clinical trial were “insulin-independent” and no longer required daily insulin therapy. A HUGE WIN — but this therapy comes with immunosuppression therapy. VX-880 is intended specifically for people with type 1 diabetes who are severely struggling to live and experiencing frequent severe hypoglycemia.
ABOUT VX-264
VX-264 involves surgically implanting a protective device containing insulin-producing stem cells into the body of a person with type 1 diabetes (T1D) without the need for immunosuppression. The first participants in this trial were enrolled in the summer of 2024.
Vertex already knows its proprietary cell product is effective at producing insulin based on its VX-880 therapy, involving immunosuppression therapy.
The VX-264 clinical trial involved the same proprietary cell product as Vertex’s VX-880 therapy but with a different method of protecting the cells from the immune system.
ABOUT VX-880
In the VX-880 trial, the stem cells were delivered via infusion into the patient’s hepatic portal vein — which carries blood through several organs, including the pancreas.

Ginger Vieira has lived with type 1 diabetes since 1999 along with a few other chronic illnesses! She is the Cofounder of the Diabetes Nerd Network and the Diabetes Nerd Marketing agency. Ginger has authored hundreds of articles and several books, including Exercise with Type 1 Diabetes, Pregnancy with Type 1 Diabetes, Dealing with Diabetes Burnout, and Stop Overeating During Lows. Over her 20-year career (so far) in diabetes, she’s produced hundreds of articles and videos about life with diabetes. Her background includes a Bachelor of Science in professional writing and certifications in coaching, personal training, powerlifting, and Ashtanga yoga.
