A manuscript published in the November 25, 2015 online issue of Science Translational Medicine reported no serious adverse reactions in the first phase 1 safety trial of a new immunotherapy approach investigating regulatory T cells (Tregs) for the treatment of type 1 diabetes (T1D). The clinical study was conducted at UCSF by Stephen E. Gitelman, MD, and Kevan C. Herold, MD, and was designed and analyzed by Jeffrey A. Bluestone, PhD. The Immune Tolerance Network helped support the mechanistic studies associated with this trial.
Tregs are a sub population of T cells that work to keep the immune system from becoming over-reactive, as it is in the case of T1D and other autoimmune diseases. Tregs have been shown to be defective in T1D, therefore an approach that adds back functional Tregs has the potential to suppress the disease state and protect the beta cells that produce insulin.
In this study, Tregs were isolated from recent-onset T1D patients, expanded ex vivo and infused back into a total of 14 patients who were divided into four dosing cohorts. Infusions contained between 5 million and 2.6 billion cells, depending on cohort, and were well tolerated at all levels. Up to 25% of the infused Tregs persisted one year after the infusion. Additionally, the expanded Tregs demonstrated enhanced functional activity. These study results support the development of a phase 2 efficacy trial for Treg immunotherapy.