A phase II clinical trial is testing the effectiveness of the vaccine bacillus Calmette-Guérin (BCG) to reverse advanced type 1 diabetes has been approved by the U.S. Food and Drug Administration (FDA).
This means the trial will begin enrolling patients in the near future, Massachusetts General Hospital reported. The five-year trial will determine whether or not repeat BCG vaccination improves the condition of adults between the age of 18 and 60 with type 1 diabetes who still have detectable levels of insulin secretion. The vaccine has already proven to reverse advanced type 1 diabetes in mice.
"We have learned a lot since the early studies in mice - not just about how BCG works but also about its potential therapeutic benefits, similar to what are being seen in trials against other autoimmune diseases," said Denise Faustman, director of the Massachusetts General Hospital (MGH) Immunobiology Laboratory and principal investigator of the study. "We are so grateful to all of the donors, large and small, who have made this trial possible - especially the Iacocca Foundation, which has believed in us and has been a supporter since our early days. Our goal is to complete enrollment and also to raise the remaining funds needed for the trial by the end of this year."
BCG is currently approved by the FDA for vaccination against tuberculosis and for the treatment of bladder cancer; it works be elevating levels of the immune modulator tumor necrosis factor (TNF). Research has shown it can temporarily eliminate abnormal white blood cells linked to autoimmune type 1 diabetes, and also stimulates regulatory T-cells.
In the phase I clinical trial, two injections of BCG administered over the course of two weeks proved to temporarily get rid of diabetes-causing T cells, triggering a small return of insulin secretions. This new trial will provide more frequent dosing over a longer period of time to determine its effectiveness.
"In the phase I clinical trial we demonstrated a statistically significant response to BCG, but our goal in phase II is to create a lasting therapeutic response," Faustman said. "We will be working again with people who have had type 1 diabetes for many years. This is not a prevention trial; instead, we are trying to create a regimen that will treat even advanced disease. In addition to our phase I trial, we took guidance from the BCG clinical trials that are underway globally for other autoimmune diseases such as multiple sclerosis."
