Novel Diabetes Immunotherapy Deemed Safe in First Trial

A new drug class that may drastically alter the treatment of diabetes recently passed its first significant test.

An experimental immunotherapy for type 1 diabetes caused no serious adverse events following infusions of up to 2.6 billion cells specially selected to protect the ability of patients to produce insulin. The majority of treatments for type 1 diabetes act by suppressing immune response, however this approach can increase the susceptibility of patients to infection or cancer.

In study that evaluated the experimental immunotherapy published online in Science Translational Medicine, regulatory T cells (Tregs) were found to inhibit attacks from the immune system on beta cells without damaging the ability to fight infection.

"This could be a game-changer," said first author Jeffrey A. Bluestone, PhD. "For type 1 diabetes, we've traditionally given immunosuppressive drugs, but this trial gives us a new way forward. By using Tregs to re-educate the immune system, we may be able to really change the course of this disease."

Researchers infused Tregs derived from the cells of patients in the trial through an ex vivo isolation and expansion procedure. This technique involves the removal of blood from patients, before a fluorescence-activated cell sorting (FACS) system segregates cells based on molecules displayed on its surface.

Investigators then separated therapeutic Tregs before placing them into a growth medium that allows them to reach a 1500-fold increase in number.

This leads to the repair of defects in the immune system, increasing the likelihood of patients with type 1 diabetes to survive long-term with more functionally active Tregs.

The trial included 14 patients, which showed the treatment to be well tolerated. Additionally, the treatment was durable, with up to 25% of infused therapeutic cells still detectable a year after the administration of a single infusion.

"The Treg intervention aims to prevent the development and progression of type 1 diabetes, freeing people like me from the daily grind of insulin therapy and lifelong fear of complications. It's truly groundbreaking research with enormous potential,” said trial participant Mary Rooney, who was diagnosed with type 1 diabetes 4 years ago.

The researchers noted that Tregs are a promising treatment approach for conditions such as autoimmune diseases, including rheumatoid arthritis and lupus, and for the treatment of cardiovascular diseases, neurological diseases, and obesity.

"Using a patient's own cells -- identifying them, isolating them, expanding them, and infusing them back into the patient -- is an exciting new pillar for drug development and we expect Tregs to be an important part of diabetes therapy in the future,” Dr. Bluestone said.