Description: Background Fumaric acid esters (FAEs) are recommended in international guidelines for induction and long-term treatment of adults with moderate-to-severe chronic plaque psoriasis. The fixed combination Fumaderm ® is approved in Germany, with dimethyl fumarate (DMF) being the main active ingredient. Objectives To assess the efficacy and safety of a new formulation of DMF (LAS41008), compared with placebo and Fumaderm ® , in adults with moderate-to-severe chronic plaque psoriasis. Methods In this phase 3, double-blind, placebo-controlled, non-inferiority trial (BRIDGE, NCT01726933, EudraCT, 2012-000055-13), patients were randomised to receive LAS41008, Fumaderm ® or placebo (2:2:1) for 16 weeks, up-titrating to a maximum daily DMF dose of 720 mg, depending upon individual response. The co-primary end points were the percentage of patients achieving Psoriasis Area and Severity Index (PASI) 75 and the percentage achieving a score of ‘clear’ or ‘almost clear’ in the Physician's Global Assessment (PGA) at week 16. Results 671 patients were randomised and included in the full analysis set (n=267, LAS41008; n=273, Fumaderm ® ; n=131, placebo). At week 16, 37.5% of patients treated with LAS41008 achieved PASI 75, compared with 15.3% receiving placebo (superiority for LAS41008 vs placebo: p〈0.0001) and 40.3% receiving Fumaderm ® (non-inferiority for LAS41008 vs Fumaderm ® : p=0.0003). 33% of patients treated with LAS41008 were ‘clear’ or ‘almost clear’ in the PGA at week 16, compared with 13.0% receiving placebo (p〈0.0001; LAS41008 superiority vs placebo) and 37.4% receiving Fumaderm ® . Most treatment-related adverse events were classed as ‘mild’ in severity. Conclusions LAS41008 (DMF) is effective in the treatment of adults with moderate-to-severe chronic plaque psoriasis. This article is protected by copyright. All rights reserved.