REmission induction of Arthritis caused by Cancer ImmunoTherapy (REACT): A Randomised, Multicentre Trial to Guide Initial Therapy for Immune Checkpoint Inhibitor-induced Inflammatory Arthritis

A clinical trial will test whether a specific treatment strategy can help cancer patients stop taking steroids for arthritis caused by immunotherapy drugs. Immune checkpoint inhibitors are powerful cancer treatments that work by unleashing the body’s immune system against tumours. But in some patients, this immune response goes awry and attacks healthy joints, causing painful inflammatory arthritis. The standard fix is high-dose steroids, but these can blunt the anti-cancer effect and cause serious side effects of their own. This trial directly compares two initial treatment approaches to see which one more effectively gets patients off steroids while keeping their arthritis under control. If the trial identifies a superior first-line strategy, it could change how rheumatologists and oncologists manage this common complication. Patients would avoid prolonged steroid exposure, potentially preserving the cancer-fighting power of their immunotherapy and reducing steroid-related harms like infections, bone thinning, and metabolic problems. The results would give clinicians a clear, evidence-based protocol for treating immunotherapy-induced arthritis, replacing the current ad-hoc approach that varies widely between hospitals. This is a pragmatic trial with immediate clinical relevance—it addresses a real-world problem that affects thousands of cancer patients each year.