• Posted December 7, 2023

Rheumatoid Arthritis Drug Could Put Brakes on Type 1 Diabetes

A drug long used to curb rheumatoid arthritis may be a potent foe against another immune disorder, type 1 diabetes.

Australian researchers report that baricitinib (Olumiant) appears to help patients newly diagnosed with type 1 diabetes maintain their natural ability to produce insulin, slowing progression of the disease.

Type 1 diabetes comprises about 5% of all diabetes cases. It occurs when the body's immune system mistakenly attacks pancreatic beta cells, which produce insulin.

Without sufficient insulin, people with type 1 diabetes typically require injected hormone to live.

"Up until now, people with type 1 diabetes have been reliant on insulin delivered via injection or infusion pump," explained study lead author Dr. Thomas Kay.

However, "our trial showed that, if started early enough after diagnosis and while the participants remained on the [oral] medication, their production of insulin was maintained," said Kay, a professor at St Vincent's Institute of Medical Research (SVI) in Melbourne.

"People with type 1 diabetes in the trial who were given the drug required significantly less insulin for treatment," he said.

The study, published Dec. 6 in the New England Journal of Medicine, is the first human trial focused on baricitinib for type 1 diabetes.

The drug works by blocking an enzyme tied to immune system regulation and inflammation. It appears to reduce the runaway immune response that's responsible for the destruction of pancreatic beta cells.

As Kay explained it, giving the drug to patients early in disease progression is crucial.

"When type 1 diabetes is first diagnosed, there is a substantial number of insulin-producing cells still present," he explained in an SVI news release. "We wanted to see whether we could protect further destruction of these cells by the immune system."

The trial was small -- just 91 people newly diagnosed with type 1 diabetes. Participants ranged in age from 10 to 30, and all had been diagnosed within 100 days prior to joining the study.

Kay's group tracked their blood sugar levels and insulin production over the course of a year. Patients were randomized to one of two groups: 60 were given baricitinib, while the other 31 received a "dummy" placebo pill. Neither patients nor researchers knew which patients were taking the drug or a placebo.

Participants continued to get their usual insulin therapy throughout the trial.

However, "people with type 1 diabetes in the trial who were given the drug required significantly less insulin for treatment," Kay noted. None of the participants were able wean themselves off insulin therapy completely, however.

In terms of blood sugar (glucose) control, the researchers said that "baricitinib improved [blood sugar] measures assessed with the use of continuous glucose monitoring."

Tests also showed that "baricitinib treatment preserved the capacity of [pancreatic] beta-cells to secrete insulin," suggesting slowed progression of the disease, according to the researchers.

Regarding any side effects from the drug, "the frequency and severity of adverse events were similar in the two trial groups, and no serious adverse events were attributed to baricitinib or placebo," Kay's group said.

The study was funded by JDRF (formerly the Juvenile Diabetes Research Foundation).

More study may be needed, but "we are very optimistic that this treatment will become clinically available," said study co-author Helen Thomas, also at SVI.

"This would be a huge step-change in how type 1 diabetes is managed, and we believe it shows promise as a fundamental improvement in the ability to control type 1 diabetes," Thomas said.

More information

Find out more about type 1 diabetes at the JDRF.

SOURCE: St. Vincent's Institute of Medical Research, news release, Dec. 6, 2023