SHIELD-T1D: Shingrix and GLP-1 Agonist for Beta-Cell Preservation in Recent-Onset Type 1 Diabetes.

Type 1 diabetes (T1D) is a chronic autoimmune disease characterized by progressive destruction of pancreatic beta cells mediated by autoreactive T lymphocytes, resulting in absolute insulin deficiency. Preservation of residual beta-cell function at the time of diagnosis is a critical therapeutic window, as even marginal endogenous insulin secretion - reflected by detectable C-peptide levels - is associated with improved glycemic control, reduced hypoglycemia burden, and decreased long-term vascular complication rates. This study evaluates the hypothesis that combinatorial immunomodulation - using the AS01B adjuvant system within the Recombinant Zoster Vaccine (RZV; Shingrix, GSK) alongside metabolic and cytoprotective support via a GLP-1 receptor agonist (semaglutide) - can synergistically preserve residual beta-cell function in adults within 100 days of T1D diagnosis. The AS01B adjuvant system activates innate immune pathways that promote regulatory T-cell (Treg) expansion and shift the immunological milieu toward tolerance, while GLP-1 receptor agonism provides direct beta-cell cytoprotection, reduces glucotoxicity, and may suppress autoimmune cytokine signaling. SHIELD-T1D is a randomized, double-blind, placebo-controlled, parallel-group Phase II clinical trial enrolling 240 adults (18-50 years) diagnosed with T1D within 100 days, with confirmed residual beta-cell function (stimulated C-peptide ≥0.2 nmol/L). Participants are randomized 1:1:1:1 to one of four arms: (1) Shingrix alone, (2) Semaglutide alone, (3) Shingrix + Semaglutide combination, or (4) dual placebo. The primary endpoint is change in 2-hour stimulated C-peptide AUC during a Mixed Meal Tolerance Test (MMTT) from baseline to 12 months. This phase II randomized, double-blind, placebo-controlled multicenter trial will evaluate the efficacy and safety of the recombinant zoster vaccine (Shingrix) and a glucagon-like peptide-1 (GLP-1) receptor agonist, alone and in combination, for preservation of res