For 6 months, the participants received either shots of the immunotherapy or the placebo at 2- or 4-week intervals. Their C-peptide levels - which are markers of insulin - were tested at 3, 6, 9, and 12 months, and they were compared with baseline levels.
The trial found no evidence of toxicity or negative side effects, and beta cells were not impaired or reduced as a consequence of the therapy. The authors write, "Treatment was well tolerated with no systemic or local hypersensitivity," which led the researchers to conclude that "proinsulin peptide immunotherapy is safe."
Additionally, "Placebo subjects showed a significant decline in stimulated C-peptide (measuring insulin reserve) at 3, 6, 9, and 12 months versus baseline, whereas no significant change was seen in the 4-weekly peptide group at these time points," say the researchers.