After the screening visit, patients will enter a washout period of 2 days, then they will be randomised to the following four treatment groups: budesonide-MMX™ tablets (6 mg), budesonide-MMX™ tablets (9 mg), Entocort® capsules (3 x 3 mg) and placebo (tablets and capsules), all administered once a day after breakfast. Hence, each patient will receive, in the morning after breakfast, either one budesonide-MMX™ 6 mg or budesonide MMX™ 9 mg tablet and 3 placebo Entocort® matching capsules, or three Entocort® 3 mg capsules and one placebo budesonide-MMX™ matching tablet, or one placebo budesonide-MMX™ matching tablet and three placebo Entocort® matching capsules.