A team of doctors and scientists from the University of California, San Francisco conducted the pioneer trial for a novel immunotherapy for the treatment of type 1 diabetes (T1D) in the United States. Results found no adverse reactions among the participants who received infusions containing as much as 2.6 billion cells that defend the body's insulin-production abilities.
T1D patients' immune system attacks the body's beta cells (insulin-generating cells) found in the pancreas. The majority of T1D therapies currently in the market address this autoimmune disease by overturning the immune response, which carry risks such as higher vulnerability to certain diseases, including cancer.
The novel therapy addresses the problem by using regulatory T cells called Tregs. The tactic is one of immune tolerance wherein the cells reduce the immune system's attack on the beta cells, but retains its capabilities to fight off infection.
"This could be a game-changer ... [b]y using Tregs to 're-educate' the immune system, we may be able to really change the course of this disease," said Jeffrey A. Bluestone, UCSF's Mary Margaret Clausen Distinguished Professor in Metabolism and Endocrinology. Bluestone is the study's first author.
The Phase 1 trial was conducted at the UCSF by Dr. Stephen E. Gitelman, professor of pediatrics and at the Yale School of Medicine by Dr. Kevan C. Herold. The Tregs used in the Phase 1 trial were obtained from the participants themselves. The team made use of the 'isolation and expansion' method first discussed by Bluestone and his research team in 2009.
The method requires retrieval of the patients' own blood, about less than two cups, where two to four million Tregs can be obtained. Using a sorting technique called fluorescence-activated cell sorting (FACS), desired Tregs are separated and then cultivated until the growth rate reaches 1,500 times.
In the previous study, Bluestone's team confirmed that Tregs produced after the expansion technique are active and can effectively repair immune system defects among T1D patients. The Treg's survival rate inside the body is also longer compared to Tregs retrieved using other methods. In the Phase 2 trial, the Treg therapy's efficacy will be tested.
The patients in the Phase 1 study ranged between 18 to 43 years old. The huge amount of Tregs infused were well tolerated among the participants. Moreover, nearly 25 percent of the infused Tregs were still evident in the participants' blood samples a year after only a single infusion.
The findings were published in the Science Translational Medicine journal on Nov. 25.
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