A Phase 2a/b Study of the Efficacy and Safety of Subcutaneous Amlitelimab in Adults With Nonresponsive Celiac Disease

This study is looking for adults between 18 and 75 years old who have been officially diagnosed with coeliac disease. You'll need to have a clear history of this diagnosis, confirmed by your doctor or medical records. Importantly, you should have been following a gluten-free diet for at least a year and are willing to continue doing so throughout the study. The study is for those whose coeliac disease symptoms haven't fully improved with the gluten-free diet alone. During the screening process, you'll need to show you have at least one moderate or severe gut symptom (like diarrhoea, tummy pain, bloating, or feeling sick) most days, which your doctor believes is linked to your coeliac disease.

There are some reasons why you might not be able to join. For example, if you have very severe forms of coeliac disease, such as refractory coeliac disease types 1 or 2, or other serious gut conditions like inflammatory bowel disease (Crohn's or ulcerative colitis), you wouldn't be eligible. Also, if you've had a recent serious gut problem like a perforation (a hole in the gut) or need certain immune-suppressing medicines for coeliac disease complications, you wouldn't be able to take part.

If you decide to take part, you'll be assigned to one of six different groups, some receiving the active medication (amlitelimab) and others a placebo (dummy medicine). The medicine will be given as an injection under the skin. You'll need to continue your usual gluten-free diet throughout the study. Some groups will also experience planned, small exposures to gluten, to help researchers understand the medicine's effect when gluten is accidentally eaten.

The study involves regular visits. If you don't choose to participate in a longer-term part of the study, you'll have up to 10 visits over about 48 weeks (just under a year). This includes a check-up period after you finish taking the study medicine. If you do join the longer-term part, you could be in the study for up to 172 weeks (over 3 years) with 22 visits. During these visits, there will be various assessments, including questionnaires about your symptoms and two procedures called gastroscopies (where a tiny camera looks inside your gut, and small tissue samples are taken) to check for changes in your gut lining.