Targeting T-cell dysfunction may hold the key to delaying type 1 diabetes onset and preserving beta-cell function. Findings from a study presented at the European Association for the Study of Diabetes Congress 2025 examined SAB-142, a fully human anti-thymocyte globulin, for its immunomodulatory effects in pre-clinical experiments and a Phase 1 clinical trial. 

In vitro, SAB-142 selectively reduced CD8 T cells while sparing regulatory T cells, promoting naïve conventional T-cell activation and proliferation. In vivo, treatment induced sustained exhaustion of CD4 and CD8 T-cell subsets, evidenced by increased PD-1 and TIGIT expression up to 120 days, without cytotoxicity. Regulatory T cells exhibited enhanced inhibitory receptor expression, potentially amplifying their suppressive function. Compared to rabbit anti-thymocyte globulin, SAB-142 uniquely modulated CD8 T cells and allowed re-dosing due to the absence of serum sickness or anti-drug antibodies. 

These findings indicate a multi-target mechanism capable of safely restoring immunotolerance, offering a promising therapeutic approach to improve disease outcomes and preserve pancreatic function in patients with type 1 diabetes.