By Hannah Millington

Copyright newsweek

A daily pill previously shown to slow the progression of type 1 diabetes has now shown a loss of therapeutic benefit when stopped—affirming the promise of the treatment.In 2023, an Australian trial reported that a daily pill of baricitinib—commonly prescribed for rheumatoid arthritis and alopecia—could safely preserve the body’s own insulin production and slow the development of type 1 diabetes in those recently diagnosed.Now, a follow-up trialpresented at the Annual Meeting of the European Association for the Study of Diabetes, held in Vienna this week, has revealed that once baricitinib treatment was stopped, participants’ diabetes progressed.They were found to produce less insulin and had less stable blood sugar levels, which were not significantly different from those on the placebo.”This is a really exciting step forward,” said study author Michalea Waibel from St Vincent’s Institute of Medical Research in Fitzroy, in a statement.”For the first time, we have an oral disease-modifying treatment that can intervene early enough to allow people with type 1 diabetes to be significantly less dependent on insulin treatment and provide time free from the demands of the disease’s daily management and which could also lower rates of long-term complications.”Nearly 4 in every 1,000 young people and 5 in every 1,000 adults in the U.S. reported having type 1 diabetes from 2019 through 2022, according to a past study.”Among the promising agents shown to preserve beta cell function in type 1 diabetes, baricitinib stands out because it can be taken orally, is well tolerated—including by young children—and is clearly efficacious,” Waibel explained.”These latest data support our previous clinical trial data by showing that the therapeutic effect is lost when baricitinib is stopped and justify further trials to determine if treatment benefit can be sustained over many years on treatment and if treating earlier stages of disease can prevent or delay clinical diagnosis.”Type 1 diabetes is caused by the immune system mistakenly attacking the insulin-producing cells in the pancreas. Over time, this leads to the need for lifelong insulin injections to manage blood sugar levels.Baricitinib, a type of Janus kinase (JAK) inhibitor, works by blocking signals in the body that lead to overactivity of the immune system, the researchers explained.This helps to protect the remaining insulin-producing cells in people who are newly diagnosed with type 1 diabetes and delay progression of full-blown symptoms.Baricitinib is already prescribed to treat several autoimmune diseases, including rheumatoid arthritis, ulcerative colitis and alopecia.The trial enrolled 91 people aged between 10 and 30 years old who had been diagnosed with type 1 diabetes in the previous 100 days. Participants were either given a baricitinib pill (4mg) or a placebo once daily for 48 weeks.At the beginning of the trial and after 12, 24 and 48 weeks, researchers measured participants’ C-peptide levels (a marker of insulin secretion) to find out how much insulin participants could make themselves.They also used continuous glucose monitoring and HbA1c (a marker of longer-term blood sugar levels) to assess the need for injected insulin and how well blood sugar levels were managed.The team discovered that taking a daily pill of baricitinib for 48 weeks preserved insulin-producing beta cell function, decreased blood glucose fluctuations and reduced the need for insulin in people newly diagnosed with type 1 diabetes. They found baricitinib to be safe, with no side effects attributed to the drug.In this study, researchers report the findings from the off-drug follow-up period, with assessments done at weeks 72 and 96.At 48 weeks the C-peptide level was 0.65 in the baricitinib group and 0.43 in the placebo group. After treatment was stopped, C-peptide levels fell to 0.49 in the baricitinib group and 0.36 in the placebo group at 72 weeks and then to 0.37 and 0.26, respectively, at 96 weeks, demonstrating reduced insulin production.The fall in insulin-producing cell function after baricitinib treatment was stopped resulted in the need for more insulin treatment, with insulin requirements at weeks 72 and 96 that were not significantly different between the groups.Coming off baricitinib also led to a deterioration in glucose control, with differences in the time spent in the safe glucose range and blood glucose fluctuations between the groups in the first 48 weeks. But these were no longer statistically significant at weeks 72 and 96.The team noted that further analyses were unable to identify any characteristic at the start of the trial that predicted treatment response, including age, specific immune system genes known as human leukocyte antigens (HLA), body mass index (BMI) or number of autoantibodies.Drug adherence (at least 80 percent of study drug taken) also did not distinguish responders from non-responders. Overall, around two-thirds of participants taking baricitinib met the criteria for response.Notably, there were no additional safety concerns raised in the follow-up period.”If we can identify people at high risk of developing type 1 diabetes with genetic tests and blood markers, they could be offered treatment even earlier to prevent the disease taking hold in the first place,” Waibel added.”We are hopeful that larger phase III trials with baricitinib are going to commence soon, in people with recently diagnosed type 1 diabetes as well as in earlier stages to delay insulin dependence.”If these trials are successful, the drug could be approved for type 1 diabetes treatment within 5 years.”Newsweek has reached out to the researchers for additional comment.Do you have a tip on a health story that Newsweek should be covering? Do you have a question about type 1 diabetes? Let us know via health@newsweek.com.ReferencesFang, M., Wang, D., & Selvin, E. (2024). Prevalence of Type 1 Diabetes Among US Children and Adults by Age, Sex, Race, and Ethnicity. JAMA, 331(16), 1411–1413. https://doi.org/10.1001/jama.2024.2103Waibel, M., So, M., Wentworth, J., Couper, J., Cameron, F., MacIsaac, R., Atlas, G., Harbison, J., Krishnamurthy, B., Gorelik, A., Vogrin, S., Villanueva, L. S., Trivedi, P., Thomas, H., & Kay, T. (2025). Baricitinib in new-onset type 1 diabetes: BANDIT 2-year outcomes. EASD 2025, Vienna.Waibel, M., Wentworth, J. M., So, M., Couper, J. J., Cameron, F. J., MacIsaac, R. J., Atlas, G., Gorelik, A., Litwak, S., Sanz-Villanueva, L., Trivedi, P., Ahmed, S., Martin, F. J., Doyle, M. E., Harbison, J. E., Hall, C., Krishnamurthy, B., Colman, P. G., Harrison, L. C., … Kay, T. W. H. (2023). Baricitinib and β-Cell Function in Patients with New-Onset Type 1 Diabetes. New England Journal of Medicine, 389(23), 2140–2150. https://doi.org/10.1056/NEJMoa2306691