Abstract
Objective: Tocilizumab (TCZ) has potent therapeutic effects in the treatment of rheumatoid arthritis (RA), but the factors for predicting these effects are not clear. We compared patients refractory to disease-modifying antirheumatic drugs (DMARDs) (biologic agent naïve: N group) and patients who had inadequate response to tumor necrosis factor (TNF) inhibitors (switch from TNF inhibitors: S group) to determine if matrix-metalloproteinase-3 (MMP-3) is a predictive factor for clinical disease activity index (CDAI) remission by TCZ treatment.
Methods: As of October 2010, the CDAI remission rate and MMP-3 levels were evaluated before treatment, every 12 weeks during treatment, and at the final observation in 96 patients treated with TCZ at 8 mg/kg at least twice every 4 weeks (N group: 43 patients, S group: 53 patients).
Results: Patients had a shorter disease duration, lower methotrexate (MTX) concomitant rate, and significantly lower erythrocyte sedimentation rate in the N group. CDAI was significantly reduced by 12 weeks in both groups, but the remission rate was significantly higher at 24 weeks and at final observation in the N group. The disease duration and the pretreatment MMP-3 level had significant effects on the achievement of CDAI remission. By group, patients in remission at the final observation had significantly lower MMP-3 levels before treatment in the N group, but no significant difference was observed in the S group.
Conclusion: The pretreatment MMP-3 level is considered to be a predictive factor for CDAI remission by TCZ in patients who are refractory to DMARDs.
