Teplizumab as immunosuppressive therapy for type I diabetes mellitus

This study evaluated the effect of teplizumab (also known as MGA031) on C-peptide levels in type I diabetes.

Type I diabetes is considered an autoimmune disease, in which the beta-cells that usually produce insulin in the pancreas are attacked by the body’s own immune system. C-peptide is a small protein that is released as a byproduct of insulin secretion, and is measured as an indicator of pancreatic function and disease progression. Typically, as type I diabetes progresses, a decline in C-peptide levels in noted.

Recent studies have suggested that the progression of type I diabetes can be regulated by immunotherapy, involving the suppression of the body’s immune response. Teplizumab is an immunosuppressant, which alters the function of white blood cells (immune cells) responsible for pancreatic damage. This study investigated the effects of teplizumab treatment on C-peptide levels, and aimed to identify patient characteristics likely to predict respond to the therapy.

83 patients with newly diagnosed type I diabetes were included in this trial. 56 patients were randomized to receive treatment with teplizumab for 2 weeks following diagnosis of type I diabetes, and again at 1 year after diagnosis, in addition to standard therapy. The remaining 27 patients were assigned to a control group, receiving standard treatment alone.

Treatment with teplizumab was found to significantly reduce C-peptide decline compared to control patients. A 75% improvement was noted in the decline rate of C-peptide levels two years following treatment. There was no significant difference in HbA1c levels (an indicator of average blood glucose levels) over the two year period between treatment groups. However, patients receiving teplizumab were noted to require significantly reduced dosages of insulin to achieve adequate glycemic control compared to patients in the control group. The most common adverse effects noted with teplizumab treatment were rash, upper respiratory infections and nausea.

Among the patients treated with teplizumab, 22 patients experienced less than a 40% decline in C-peptide levels and were classified as good responders to teplizumab treatment. Analysis showed good responders were typically those with lower initial HbA1c levels at the time of randomization. These findings suggest the importance of early intervention in delaying disease progression.

This study concluded that immunosuppressant therapy with teplizumab may significantly delay the loss of pancreatic function among newly diagnosed type I diabetics.

This authors of this study declared a vested interest in MacroGenics, which developed and manufactures teplizumab.

Consult with your physician regarding the potential benefits of immunotherapy in the treatment of type I diabetes.