Barriers to Screening: An Analysis of Factors Impacting Screening for Type 1 Diabetes Prevention Trials

Oral Insulin Delay of Stage 3 Type 1 Diabetes Revisited in HLA DR4-DQ8 Participants in the TrialNet Oral Insulin Prevention Trial (TN07)

OBJECTIVE

To explore if oral insulin could delay onset of stage 3 type 1 diabetes (T1D) among patients with stage 1/2 who carry HLA DR4-DQ8 and/or have elevated levels of IA-2 autoantibodies (IA-2As).

RESEARCH AND METHODS

Next-generation targeted sequencing technology was used to genotype eight HLA class II genes (DQA1, DQB1, DRB1, DRB3, DRB4, DRB5, DPA1, and DPB1) in 546 participants in the TrialNet oral insulin preventative trial (TN07). Baseline levels of autoantibodies against insulin (IAA), GAD65 (GADA), and IA-2A were determined prior to treatment assignment. Available clinical and demographic covariables from TN07 were used in this post hoc analysis with the Cox regression model to quantify the preventive efficacy of oral insulin.

RESULTS

Oral insulin reduced the frequency of T1D onset among participants with elevated IA-2A levels (HR 0.62; P = 0.012) but had no preventive effect among those with low IA-2A levels (HR 1.03; P = 0.91). High IA-2A levels were positively associated with the HLA DR4-DQ8 haplotype (OR 1.63; P = 6.37 × 10-6) and negatively associated with the HLA DR7-containing DRB1*07:01-DRB4*01:01-DQA1*02:01-DQB1*02:02 extended haplotype (OR 0.49; P = 0.037). Among DR4-DQ8 carriers, oral insulin delayed the progression toward stage 3 T1D onset (HR 0.59; P = 0.027), especially if participants also had high IA-2A level (HR 0.50; P = 0.028).

CONCLUSIONS

These results suggest the presence of a T1D endotype characterized by HLA DR4-DQ8 and/or elevated IA-2A levels; for those patients with stage 1/2 disease with such an endotype, oral insulin delays the clinical T1D onset.

Comparisons of Metabolic Measures to Predict T1D vs Detect a Preventive Treatment Effect in High-Risk Individuals

CONTEXT

Metabolic measures are frequently used to predict type 1 diabetes (T1D) and to understand effects of disease-modifying therapies.

OBJECTIVE

Compare metabolic endpoints for their ability to detect preventive treatment effects and predict T1D.

METHODS

Six-month changes in metabolic endpoints were assessed for (1) detecting treatment effects by comparing placebo and treatment arms from the randomized controlled teplizumab prevention trial, a multicenter clinical trial investigating 14-day intravenous teplizumab infusion and (2) predicting T1D in the TrialNet Pathway to Prevention natural history study. For each metabolic measure, t-Values from t tests for detecting a treatment effect were compared with chi-square values from proportional hazards regression for predicting T1D. Participants in the teplizumab prevention trial and participants in the Pathway to Prevention study selected with the same inclusion criteria used for the teplizumab trial were studied.

RESULTS

Six-month changes in glucose-based endpoints predicted diabetes better than C-peptide-based endpoints, yet the latter were better at detecting a teplizumab effect. Combined measures of glucose and C-peptide were more balanced than measures of glucose alone or C-peptide alone for predicting diabetes and detecting a teplizumab effect.

CONCLUSION

The capacity of a metabolic endpoint to detect a treatment effect does not necessarily correspond to its accuracy for predicting T1D. However, combined glucose and C-peptide endpoints appear to be effective for both predicting diabetes and detecting a response to immunotherapy. These findings suggest that combined glucose and C-peptide endpoints should be incorporated into the design of future T1D prevention trials.

Efficacy of mesenchymal stromal cells in the treatment of type 1 diabetes: a systematic review

To investigate the efficacy of mesenchymal stromal cells in the treatment of type 1 diabetes. Articles about the effects of mesenchymal stromal cells for T1D were retrieved in PubMed, Web of Science, Embase, and the Cochrane Library databases up to July 2023. Additional relevant studies were manually searched through citations. HbA1c, FBG, PBG, insulin requirement and C-peptide were assessed. The risk of bias was evaluated with the ROB 2.0 and ROBINS-I tools. Six RCTs and eight nRCTs were included. Of the 14 studies included, two evaluated BM-MSCs, three evaluated UC-MSCs, five evaluated AHSCT, two evaluated CB-SCs, and two evaluated UC-SCs plus aBM-MNCs. At the end of follow-up, ten studies found that mesenchymal stromal cells improved glycemic outcomes in T1D, while the remaining four studies showed no significant improvement. Findings support the positive impacts observed from utilizing mesenchymal stromal cells in individuals with T1D. However, the overall methodological quality of the identified studies and findings is heterogeneous, limiting the interpretation of the therapeutic benefits of mesenchymal stromal cells in T1D. Methodically rigorous research is needed to further increase credibility.

Teplizumab: promises and challenges of a recently approved monoclonal antibody for the prevention of type 1 diabetes or preservation of residual beta cell function

INTRODUCTION

Type 1 diabetes (T1D) is a chronic autoimmune endocrinopathy with increasing incidence that results in the depletion of pancreatic beta cells and exogenous insulin dependence. Despite technological advances in insulin delivery, disease control remains suboptimal, while previous immunotherapy options have failed to prevent T1D. Recently, teplizumab, an immunomodulating monoclonal antibody, was approved to delay or prevent T1D.

AREAS COVERED

Five randomized controlled trials have tested different regimens of administration, mostly 14-day schemes with dose escalation. In participants with new-onset T1D, teplizumab delayed C-peptide decline, improved glycemic control, and reduced insulin demand for a median of 1 or 2 years. Studies in at-risk relatives of patients showed a decrease in T1D incidence during 2 years of follow-up. Subgroups of responders with unique metabolic and immunological characteristics were identified. Mild to moderate adverse effects were reported, including transient rash, cytopenia, nausea, vomiting, and infections.

EXPERT OPINION

Teplizumab marks a turning point in T1D therapy. Areas of future research include the ideal population for screening, cost-effectiveness, and challenges in treatment accessibility. More studies are essential to evaluate the ideal duration of the regimen, the potential benefit of combinations with other drugs, and to identify endophenotypes with a high probability of response.