The Norwegian Drug Monitoring Study

Infliximab and other TNF-inhibitors have revolutionised the treatment of several immunological inflammatory diseases. Still, more than half of the patients either do not respond sufficiently to infliximab therapy or loose efficacy over time. The large individual variation in the serum drug concentrations on standard doses and the development of anti-drug antibodies are thought to be main reasons for these treatment failures. An individualised treatment strategy based on systematic assessments of serum drug concentrations, therapeutic drug monitoring, has been proposed as a clinical tool to optimise efficacy of infliximab treatment. Therapeutic drug monitoring seems reasonable both from a clinical and an economical point of view, but the effectiveness of this treatment strategy still remain to be shown. The NOR-DRUM study is planned as a national, randomised controlled multicentre trial in two parts aiming to assess the effectiveness of therapeutic drug monitoring in order to achieve remission in patients with immunological inflammatory diseases starting infliximab treatment (part A) and in order to maintain disease control in patients on maintenance infliximab treatment (part B). The results of the NOR-DRUM study will hopefully contribute to an implementation of a personalised medicine approach to treatment with infliximab and other biological drugs.


Eligibility Criteria:
Inclusion Criteria:

NOR-DRUM A

1. A clinical diagnosis of one of the following; rheumatoid arthritis, spondyloarthritis (including ankylosing spondylitis), psoriatic arthritis\*, ulcerative colitis, Crohn's disease or chronic plaque psoriasis
2. Male or non-pregnant female
3. ≥18 and \< 75 years of age at screening
4. A clinical indication to start INX
5. Subject not in remission according to diagnosis-specific disease activity scores
6. Subject capable of understanding and signing an informed consent form

   * Patients with psoriatic arthritis with predominantly axial manifestations should be included and assessed as spondyloarthritis

NOR-DRUM B

1. A clinical diagnosis of one of the following; rheumatoid arthritis, spondyloarthritis (including ankylosing spondylitis), psoriatic arthritis\*, ulcerative colitis, Crohn's disease or chronic plaque psoriasis
2. Male or non-pregnant female
3. ≥18 and \< 75 years of age at screening
4. On maintenance therapy with infliximab for a minimum of 30 weeks and a maximum of 3 years
5. A clinical indication for further infliximab treatment
6. Subject capable of understanding and signing an informed consent form

   * Patients with psoriatic arthritis and predominantly axial manifestations should be included and assessed as spondyloarthritis

Exclusion Criteria:

NOR-DRUM A

1. Major co-morbidities, such as previous malignancies within the last 5 years, severe diabetes mellitus, severe infections (including HIV), uncontrollable hypertension, severe cardiovascular disease (NYHA class 3 or 4), severe respiratory diseases, demyelinating disease, significant chronic widespread pain syndrome, laboratory abnormalities or significant renal or hepatic disease and/or other diseases or conditions where treatment with infliximab is either found contra-indicated by the clinician or which make adherence to the protocol difficult
2. A positive screening for TB and hepatitis
3. Inadequate birth control, pregnancy or subject considering becoming pregnant during the study period
4. Psychiatric or mental disorders, alcohol abuse or other substance abuse, language barriers or other factors which makes adherence to the study protocol difficult
5. Prior use of infliximab within the last 6 months

NOR-DRUM B

1. Major co-morbidities, such as previous malignancies within the last 5 years, severe diabetes mellitus, severe infections, uncontrollable hypertension, severe cardiovascular disease (NYHA class 3 or 4), severe respiratory diseases, demyelinating disease, significant chronic widespread pain syndrome, laboratory abnormalities or significant renal or hepatic disease and/or other diseases or conditions where treatment with infliximab is either found contra-indicated by the clinician or which make adherence to the protocol difficult
2. Inadequate birth control, pregnancy or subject considering becoming pregnant during the study period
3. Psychiatric or mental disorders, alcohol abuse or other substance abuse, language barriers or other factors which makes adherence to the study protocol difficult