Researchers from the Faustman Laboratory at Massachusetts General Hospital, who successfully carried out Phase I of bacillus Calmette-Guérin (BCG) human clinical trials, presented the interim results of their phase II research at the 77th Scientific Sessions of the American Diabetes Association on June 10.
The researchers have previously found that proper BCG treatment could result in permanent reversal from the autoimmune disease. During the presentation, principal investigator Dr. Denise Faustman offered an explanation with regard to how the BCG potentially works to prevent and treat type-1 diabetes.
How BCG Vaccine Works Against Type-1 Diabetes
According to Dr. Faustman, the effectiveness of the BCG vaccine lies in how it encourages a permanent increase in regulatory genes that prevent an autoimmune response. Their findings show that the BCG vaccine targets rogue T-cells that mistakenly attack insulin secreting islets. When the attacks let up, the immune system gets a much need reboot to enable cells to properly function and Tregs, the immune system "brakes" which should have been able to stop rogue cells, would be able to function properly again and stop further attacks.
"The vaccine actually resets your genes to restore normality," Dr. Faustman said.
BCG Vaccine Human Clinical Trials
Dr. Faustman's research team was the first to confirm positive results with using the BCG vaccine to target abnormal cells that cause autoimmune diseases. Specifically, mice with advanced type-1 diabetes fully recovered from the disease using the treatment.
Findings from the Phase I trials, which concluded in 2012, show that the vaccine BCG may be capable of fully restoring balance in human genes to stimulate remission from Type-1 diabetes, but administration of the vaccine only happened twice over the course of four weeks. A longer time frame was needed to determine whether a more permanent solution could be achieved.
In 2015, the team followed-up with a 5-year long U.S. Food and Drug Administration approved human clinical trial that showed great but partial improvement in the condition of patients with Type-1 diabetes. This was done by injecting type-1 diabetic patients with the BCG vaccine twice over a four week period. Results showed that the vaccine removed harmful T cells and even allowed some of the patients to produce insulin.
For Phase II of the human clinical trials, which involves 150 patients, Dr. Faustman's team aims to determine whether repeated BCG vaccinations over a longer period of time would make the reversal permanent, even for more advanced cases. In order to do this, the team is trying to figure out the proper dosage and schedule for BCG vaccine administration.