Associations between certolizumab pegol serum levels, anti-drug antibodies and treatment response in patients with inflammatory joint diseases: data from the NOR-DMARD study

Arthritis Res Ther. 2019 Nov 29;21(1):256. doi: 10.1186/s13075-019-2009-5.


Objectives: To identify a therapeutic target interval for certolizumab pegol drug levels and examine the influence of anti-drug antibodies in patients with inflammatory joint diseases.

Methods: Certolizumab pegol and anti-drug antibody levels were measured in serum samples collected after 3 months of certolizumab pegol treatment in 268 patients with inflammatory joint diseases (116 axial spondyloarthritis, 91 rheumatoid arthritis and 61 psoriatic arthritis) in the NOR-DMARD study. Treatment response was defined by Ankylosing Spondylitis Disease Activity Score Clinically important improvement in axial spondyloarthritis, European League Against Rheumatism good/moderate response in rheumatoid arthritis, and improvement in 28-joint Disease Activity Score of ≥ 0.6 in PsA. Serum drug levels and anti-drug antibodies were analysed using automated in-house assays.

Results: Certolizumab pegol serum levels varied considerably between individuals (median (IQR) 32.9 (17.3-43.9) mg/L). Certolizumab pegol level ≥ 20 mg/L was associated with treatment response for the total inflammatory joint disease population, with odds ratio (OR) 2.3 (95% CI 1.2-4.5, P = 0.01) and OR 1.9 (95% CI 1.0-3.5, P = 0.05) after 3 and 6 months of treatment, respectively. For individual diagnoses, this association was most consistent for axial spondyloarthritis, with OR 3.4 (95% CI 1.0-11.1, P < 0.05) and OR 3.3 (95% CI 1.0-10.8, P < 0.05), respectively. Certolizumab pegol level > 40 mg/L was not associated with any additional benefit for any of the diagnoses. Anti-drug antibodies were detected in 6.1% (19/310) of samples and were associated with low certolizumab pegol levels (P < 0.01).

Conclusions: Serum certolizumab pegol levels 20-40 mg/L were associated with treatment response in inflammatory joint diseases. Our study is the first to show this association in axial spondyloarthritis and psoriatic arthritis patients. The results suggest a possible benefit of therapeutic drug monitoring in patients with inflammatory joint disease on certolizumab pegol treatment.

Trial registration: NCT01581294, April 2012.

Keywords: Anti-drug antibodies; Axial spondyloarthritis; Certolizumab pegol; Inflammatory joint diseases; Psoriatic arthritis; Rheumatoid arthritis; Serum drug levels; TNF-inhibitors.

Publication types

  • Clinical Trial, Phase IV
  • Observational Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Antibodies / blood
  • Antibodies / immunology
  • Antirheumatic Agents / blood
  • Antirheumatic Agents / immunology
  • Antirheumatic Agents / therapeutic use
  • Arthritis, Psoriatic / drug therapy*
  • Arthritis, Rheumatoid / drug therapy*
  • Certolizumab Pegol / blood
  • Certolizumab Pegol / immunology
  • Certolizumab Pegol / therapeutic use*
  • Female
  • Humans
  • Longitudinal Studies
  • Male
  • Middle Aged
  • Spondylarthritis / drug therapy*
  • Spondylitis, Ankylosing / drug therapy*
  • Treatment Outcome


  • Antibodies
  • Antirheumatic Agents
  • Certolizumab Pegol

Associated data