Researchers from Massachusetts General Hospital (MGH) Immunobiology Laboratory announce findings from a phase I clinical trial that shows the generic drug BCG (bacillus Calmette-Guerin) transiently reversed type 1 diabetes in humans.
According to Denise Faustman, MD, PhD, director of MGH, "We found that even low doses of BCG could transiently reverse type 1 diabetes in human patients."
Phase II BCG trial underway for diabetes type 1 vaccine
The success of the phase I trial means the BCG vaccine, currently approved by the U.S. FDA for vaccination against tuberculosis and for the treatment of bladder cancer, is now in Phase II trials, starting earlier this month at MGH; funded by the Iacocca Foundation.
Researchers say BCG vaccine was able to reverse type 1 diabetes by boosting tumor necrosis factor (TNF), which eliminates abnormal white blood cells responsible for type1 diabetes. The effect was seen in mice and in humans.
Treatment with the vaccine allows the pancreas to produce insulin to keep blood sugar levels in check.
Faustman explains, “One of the key components of this study was our development of a way to measure the death of the autoreactive T cells that destroy the ability of the pancreas to produce insulin. Not only did we observe and measure the death of these self-targeting immune cells, but we also saw evidence of restoration of insulin production even in patients who've had type 1 diabetes for more than a decade."
For the study, six patients with type 1 diabetes, diagnosed for an average of 15 years, received either two injections of placebo or BCG, four weeks apart.
Blood levels of autoreactive T cells, regulatory T cells that control immunity, autoantibodies that measure activity in the pancreas and levels of C-peptide that reflects insulin secretion were measured in the study participants.
Researchers compared the results to six nondiabetics and also compared the findings to samples from 75 participants with diabetes and 15 who were not diagnosed with the disease.
Importantly, there was a temporary boost in insulin secretion, shown by increased levels of C-peptide among patients treated with BCG.
Most of the participants given the drug experienced increase in numbers of regulatory T-cells and death of autoreactive T-cells.
The scientists also noted one participant developed Epstein-Barr virus, which is known to promote expression of TNF.
"These data support our hypothesis that BCG may benefit human type 1 diabetes by boosting TNF levels," says Faustman.
The data from the EBV-infected patient show that induction of TNF expression from diverse sources may have been a missing component in two recent, unsuccessful Phase III trials that tested antibodies against the immune molecule CD3 in type 1 diabetes patients. Those trials were specifically designed to avoid reactivating any latent EBV infection, but blocking EBV activation could also block TNF expression."
Lee Iacocca is personally committed to finding a cure for type 1 diabetes.
He says, “We are hopeful that this continued research will lead to an effective and inexpensive therapy for people with the disease. I made a commitment to my late wife that I would work to find a cure for type 1 diabetes – and I, along with my daughters, continue to keep that promise."
Phase I trials for BCG vaccine show success. The drug, which has been around for 90 years and is inexpensive, may offer new treatment for those with type 1 diabetes. In clinical trials, BCG temporarily reversed the disease in mice and in humans. For more information, or to lend support, visit
http://www.faustmanlab.org.