Adalimumab will be supplied as a sterile solution without preservatives for subcutaneous injection in 1 ml prefilled syringes containing adalimumab 40 mg/0.8 ml, to be self-injected by the patient every 2 weeks until week 20. After week 20 patients continue adalimumab treatment 40 mg every other week but may change to injections with pens containing the same drug and dosage. The drug is injected under the skin of the abdomen or the thigh. All patients will be instructed by the study personnel in correct sterile subcutaneous injection of the study drug.