The NOR-SWITCH Study

Inclusion criteria

• A clinical diagnosis of either rheumatoid arthritis, spondyloarthritis, psoriatic arthritis, ulcerative colitis, Crohn's disease or chronic plaque psoriasis
• Male or non-pregnant, non-nursing female
• >18 years of age at screening
• Stable treatment with innovator infliximab (Remicade) during the last 6 months
• Subject capable of understanding and signing an informed consent form
• Provision of written informed consent

Exclusion criteria

• Major co-morbidities, such as severe malignancies, severe diabetic mellitus, severe infections, uncontrollable hypertension, severe cardiovascular disease (NYHA class 3 or 4) and/or severe respiratory diseases
• Change of major co-medication during the last 2 months prior to randomization:

RA, SpA and PsA: Initiation of systemic corticosteroids or synthetic DMARDs or other medication which according to the investigator would interfere with the stability of the disease.

UC and CD: Initiation of systemic corticosteroids or an immunosuppressant or other medication which according to the investigator would interfere with the stability of the disease Psoriasis: Initiation of synthetic DMARDs or other medication which according to the investigator would interfere with the stability of the disease

• Inadequate birth control, pregnancy, and/or breastfeeding
• Psychiatric or mental disorders, alcohol abuse or other substance abuse, language barriers or other factors which makes adherence to the study protocol impossible
• Change in treatment with innovator infliximab (Remicade) during the last 6 months due to disease related factors, not including dose/frequency adjustments due to drug concentration measurements