Efficacy and safety of filgotinib as induction and maintenance therapy for Crohn's disease (DIVERSITY): a phase 3, double-blind, randomised, placebo-controlled trial

BACKGROUND: There is a need for efficacious therapies for patients with Crohn's disease that are better tolerated and more durable than available treatments. We aimed to evaluate the efficacy and safety of filgotinib, an oral Janus kinase 1 preferential inhibitor, for treating Crohn's disease. METHODS: This phase 3, double-blind, randomised, placebo-controlled trial was conducted in 371 centres in 39 countries. Eligible patients were aged 18-75 years with moderately to severely active Crohn's disease for at least 3 months before enrolment. Patients were enrolled into one of two induction studies on the basis of their experience with biological agents (induction study A included biologic-naive and later biologic-experienced patients and induction study B included biologic-experienced patients). In both induction studies, patients were randomly assigned (1:1:1), using an interactive web response system, to receive oral filgotinib 200 mg, filgotinib 100 mg, or placebo once daily for 11 weeks. Patients who received filgotinib and had two-item patient-reported outcome (PRO2) clinical remission or an endoscopic response at week 10 were re-randomised (2:1) to receive their induction dose or placebo orally, once daily to the end of week 58 in the maintenance study. Co-primary endpoints were PRO2 clinical remission and an endoscopic response at week 10 (induction studies) and week 58 (maintenance study). PRO2 clinical remission was defined as an abdominal pain subscore of not more than 1 and a liquid or very soft stool frequency subscore of not more than 3 (from eDiary data) and endoscopic response was defined as a reduction of at least 50% in Simple Endoscopic Score for Crohn's disease from induction baseline (from central reading of endoscopy). For the induction studies, efficacy was assessed in all randomly assigned patients who received at least one dose of study drug. For the maintenance study, efficacy was assessed in all patients from either filgotinib treatment group in the induction studies who reached PRO2 clinical remission or an endoscopic response at week 10, and who were re-randomised and received at least one dose of study drug in the maintenance study. Patients who received placebo throughout the induction and maintenance studies were not included in the full analysis set for the maintenance study. Safety was assessed in all patients who received at least one dose of study drug. This trial is complete and is registered with ClinicalTrials.gov, NCT02