 This will be a drug-drug interaction study to evaluate the effect of multiple oral doses of GLPG1837 on the single dose pharmacokinetic profile of midazolam administered in fed healthy male subjects. Each subject will receive a single oral dose of midazolam 2 mg on 2 occasions: on Day 1, before dosing with GLPG1837 and on Day 12 co-administered with GLPG1837, after multiple oral doses of GLPG1837 daily for 10 days, from Day 2 until Day 11. 