Predictive value of serum amyloid a levels for requirement of concomitant methotrexate in tocilizumab initiation: A post hoc analysis of the SURPRISE study

Mod Rheumatol. 2020 May;30(3):442-449. doi: 10.1080/14397595.2019.1621026. Epub 2019 Jun 7.


Objectives: To identify predictive factors for remission by tocilizumab monotherapy in rheumatoid arthritis (RA) patients.Methods: This is a post hoc analysis of the SURPRISE study, a 2-year randomized, controlled study comparing the efficacy of tocilizumab with (ADD-ON) and without methotrexate (SWITCH). The primary endpoint was DAS28-ESR remission (<2.6) at week 24. The change in modified total Sharp score from baseline to week 52 (ΔmTSS/year) was also assessed as an endpoint. The effect of clinical parameters at baseline on remission was estimated by logistic regression analysis.Results: In SWITCH (n = 96), CRP, SAA, RF, and DAS28 at baseline showed predictive value for DAS28 remission in unadjusted analysis. Adjusted analysis confirmed SAA and DAS28 as predictive factors, with SAA having the highest value (ROC-AUC = 0.731). Furthermore, structural remission (ΔmTSS/year ≤ 0.5) rate was significantly higher in patients with SAA of < 50.0 μg/mL than other patients. In contrast, in ADD-ON (n = 98), only DAS28 showed predictive value for DAS28 remission. In patients with SAA < 50.0 μg/mL, both DAS28 remission and structural remission rate were comparable between SWITCH and ADD-ON.Conclusion: RA patients with low SAA levels at baseline may benefit similarly from tocilizumab with and without methotrexate.Trial registration number: NCT01120366.

Keywords: Monotherapy; prediction; remission; serum amyloid A; tocilizumab.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Antibodies, Monoclonal, Humanized / administration & dosage
  • Antibodies, Monoclonal, Humanized / therapeutic use*
  • Antirheumatic Agents / administration & dosage
  • Antirheumatic Agents / therapeutic use*
  • Arthritis, Rheumatoid / drug therapy*
  • Biomarkers / blood
  • Drug Administration Schedule
  • Female
  • Humans
  • Male
  • Methotrexate / administration & dosage
  • Methotrexate / therapeutic use*
  • Middle Aged
  • Serum Amyloid A Protein / analysis*


  • Antibodies, Monoclonal, Humanized
  • Antirheumatic Agents
  • Biomarkers
  • Serum Amyloid A Protein
  • tocilizumab
  • Methotrexate

Associated data