Two-year data from the ITN’s START Trial (Study of Thymoglobulin to ARest T1D) found that antithymocyte globulin (ATG) did not preserve insulin production in the majority of type 1 diabetes patients, but did show benefit in a subset of older participants. The results were published recently in Diabetalogia.
The START Trial, led by Dr. Steve Gitelman at the University of California, San Francisco, tested whether ATG, a T cell depleting agent used to prevent organ transplant rejection, could alter autoimmune processes and help preserve insulin production in new-onset type 1 diabetes. The study randomized 58 participants ages 12-35 to treatment with a short course of ATG or placebo and measured participants’ C-peptide production, an indicator of islet function, out to two years.
The recently-published data show no statistically significant difference in islet function between the ATG and placebo groups at two years, with both groups experiencing declines in C-peptide from baseline. Post-hoc analyses found, however, that older participants (ages 22-35) treated with ATG maintained better C-peptide production throughout the course of the trial. Participants were considered “full responders” if after two years there was no loss in C-peptide production compared with baseline levels. In the ATG-treated group, 11 of 35 evaluable participants were considered full responders, and nine of these 11 were aged 22-35. Only two out of 16 evaluable participants in the placebo group were considered full responders at two years. These findings may warrant further studies to assess the benefits of ATG in older populations.