The following is a summary of “Improvement or Worsening of Disease Activity After Switch to Sarilumab in Patients With Rheumatoid Arthritis With a Partial Response to Adalimumab,” published in the March 2023 issue of Rheumatology by Curtis, et al.

For a study, researchers sought to evaluate the impact of transitioning from adalimumab to sarilumab monotherapy in patients with rheumatoid arthritis who were partial responders, using data from the MONARCH randomized trial and its open-label extension (OLE).

Partial response was defined as an improvement in the Clinical Disease Activity Index (CDAI) by either 6 or 12 units, based on the baseline score (baseline score: >22 or >10 and ≤22, respectively). The study assessed the proportions of adalimumab partial responders who experienced meaningful worsening or improvement at weeks 12 and 24 of the OLE using various thresholds, including CDAI (≥6 and ≥12 points), 28-joint Disease Activity Score (≥0.6 and ≥1.2 points), Health Assessment Questionnaire Disability Index (≥0.22 and ≥0.30 points), Simple Disease Activity Index (≥7 and ≥13 points), physician and patient global assessments (≥10 and ≥20), and swollen and tender joint counts (≥1 and ≥2 joints). Mixed-effect models with repeated measures were employed for analyzing outcomes in observed cases, and p-values were determined using Wilcoxon tests.

Among the 369 enrolled patients, 320 (87%) participated in the OLE, and 155 switched from adalimumab to sarilumab. Of the switch group, 59% (91/155) were partial responders. At week 24, 4% to 17% and 2% to 12% of partial responders experienced meaningful worsening using lower and higher thresholds, respectively, while 47% to 78% and 27% to 66% showed improvement.

For partial responders to adalimumab, transitioning to sarilumab monotherapy was associated with a low likelihood of experiencing a significant worsening of disease activity. Instead, most patients demonstrated meaningful improvement or experienced no significant change. The findings may provide reassurance to patients considering a switch to treatment with a different mechanism of action, alleviating concerns about the potential worsening of their condition.