This study tests a new treatment called **amlitelimab** for adults with **non-responsive celiac disease** (NRCD). Celiac disease is when your immune system reacts badly to gluten, a protein found in wheat, barley, and rye. NRCD means your symptoms don't improve even when you avoid gluten. The study checks if amlitelimab helps the small intestine heal and improves symptoms. It compares amlitelimab to a placebo, which is a fake treatment to see if the real drug has an effect. **Key Points:** - The study lasts up to **48 weeks** (or 172 weeks if you choose to continue), with **10 to 22 visits**. - Participants must be on a **gluten-free diet** for at least a year and be willing to continue it. - Participants must be ready for **two endoscopies**, a test involving a small camera to check your intestines. This study is **double-blind**, meaning neither you nor the researchers know if you get amlitelimab or placebo, to ensure fair testing. If you have certain severe health issues or other active inflammatory diseases, you may not be eligible.