A Stanford University School of Medicine-led clinical trial reveals that a new vaccine, designed to combat Type 1 diabetes, could be selectively countering the errant immune responses of the disease.
“We’re very excited by these results, which suggest that the immunologist’s dream of shutting down just a single subset of dysfunctional immune cells without wrecking the whole immune system may be attainable,” said Dr. Lawrence Steinman, professor of pediatrics and of neurology and neurological sciences at Stanford. “This vaccine is a new concept. It’s shutting off a specific immune response, rather than turning on specific immune responses as conventional vaccines for, say, influenza or polio aim to do.”
The clinical trial involved multiple centers, was randomized and double blind. The results were published in the journal Science Transitional Medicine on June 26. The results reveal that the blood born proxy of insulin was maintained and even increased in some instances during the 12 weeks of dosing. These results suggest that people who obtain the vaccine may suffer less destruction of beta cells on an ongoing basis compared to those receiving placebo injections. Beta cells produce and release peptide hormone insulin after meals.
The results also reveal that a specific group of immune cells, known to destroy protein on beta cells, were depleted in test subjects that received the vaccine.
Scientists added modified genetic material to DNA and administered the vaccine on a weekly basis through intramuscular injections. Eighty of the total number of study participants received the injections. All 80 were previously diagnosed with Type 1 diabetes and were currently using insulin replacement therapy injections for treatment. There were 5 different participant groups involved. Four groups all received different dosage sizes of the vaccine while the fifth received the placebo injection. The group that received the placebo was given the option of receiving the vaccine for 12 weeks after the 12 week trial was finished.
The C-peptide levels and other specific blood components of each study participant were monitored at baseline, 5 weeks, 15 weeks, 6 months, 9 months, 12 months, 18 months and 24 months. During each evaluation, blood was drawn at the 30, 60, 90 and 120-minute mark, following the consumption of a modified milkshake. Those blood samples were then preserved and sent to Dr. Bart Roep’s lab for evaluation. Dr. Roep is the lead author of the study and a professor of immunology at Leiden University Medical Center in the Netherlands.
There were no adverse reactions observed during the clinical trial. The study also reported that several weeks after the 12-week dosing regimen, beneficial effects began to decrease. The results of the trial must be confirmed by a larger study that is longer in duration, explains Dr. Lawrence Steinman, professor of pediatrics, neurology and neurological sciences at Stanford. No DNA based vaccine has ever been approved for human use.