Rituximab is FDA-approved to treat several autoimmune diseases,
including Rheumatoid Arthritis (RA). About 10 years ago there were a couple of clinical trials testing it for T1D, and the results were medium-good. I blogged on those: https://cureresearch4type1diabetes.blogspot.com/search/label/Rituximab
Abatacept is FDA-approved to treat adult Rheumatoid Arthritis, as well as Juvenile Idiopathic Arthritis (JIA) in children as young as six. I blogged on those: https://cureresearch4type1diabetes.blogspot.com/search/label/Abatacept but not on the most recent results, which are here: https://diabetesjournals.org/care/article/46/5/1005/148547/Abatacept-for-Delay-of-Type-1-Diabetes-Progression and were unsuccessful on the primary end point, but some interesting data on the lessor end points.
Rituximab suppresses CD20 cells, which are a subset of the immune system's B cells (different from the pancreas's beta cells). Hopefully this will block the autoimmune attack. B cells communicate with the T cells, which actually attack the body's beta cells in the pancreas. By targeting the B cells, it is hoped this treatment will stop or lower the attack of the T cells.
Abatacept is a treatment that prevents T-cells from becoming activated. Presumably, for type-1 diabetes, it works by blocking the "bad" killer T-cells from activating.
So you can see how these two drugs can work together to have a stronger effect than either alone.
The Study
This study will enroll 76 honeymooners (within 100 days of diagnosis), between 8 and 45 years old. Everyone will be treated with Rituximab once a week for 4 weeks. This is an IV infusion which will take 3-8 hours. There is then a 3 month period without treatment, and then 2/3s of the people will get Abatacept. That is a weekly injection (much like injecting insulin) which will go for 20 months. 1/3rd of the people will get a placebo and be the control group. (So everyone gets Rituximab, but not everyone gets Abatacept.)
Everyone will then be followed for a total of 4 years, so 2 years after the last treatment. The primary end point is C-peptides and secondary endpoints include immune measurements to see how the treatment effects people.
The study started in Oct-2023 and is expected to end between Oct-2027 and Oct-2029. However, since they are still recruiting, and the study follows people for 4 years, I don't see how it can finish before mid-2028.
They are recruiting in 13 locations in the United States plus Melbourne, Australia. The full list is in the clinical trial link below or you can get in touch with the study contacts:
Ariana Rojas +1-813-974-682 ariana.rojas@epi.usf.edu
Melissa Parker +1-813-396-9378 melissa.parker@epi.usf.edu
Web Site: https://www.trialnet.org/our-research/newly-diagnosed-t1d/t1d-relay
Clinical Trial Registration: https://www.clinicaltrials.gov/study/NCT03929601
Discussion
This study tries to combine two treatments with lackluster results into something better. Of course, I have no idea if it will work, but if it does, that is good news in two different ways. First, as a promising honeymoon treatment to delay or even prevent T1D, that is the direct goal of this trial. But second, many researchers believe that two different immune drugs (with two different mechanisms) might be a lot better than one immune drug alone. They may interact synergistically. A success here would show that two drugs together could be much more than either one alone, and that could open the flood doors of combination drug trials.
