To explore predictive factors including MMP-3 for achievement of low disease activity (LDA) at 52 weeks in bio-switch rheumatoid arthritis (RA) patients treated with abatacept, for whom obtaining a good clinical response can be difficult.
Participants were 423 consecutive patients with RA treated with abatacept who were observed for longer than 52 weeks and registered in the TBCR, a Japanese multicentre registry system. Multivariate logistic regression analysis was used to study factors that predict the achievement of LDA at 52 weeks in bio-naïve (n=234) and bio-switch (n=189) groups.
ROC analysis revealed that MMP-3 improvement rates at 12 weeks in bio-switch patients had the highest AUC with a cut-off value of 20.0% for predicting LDA achievement at 52 weeks. Multivariate logistic regression analysis revealed that, in addition to DAS28-CRP at baseline, achieving 20% improvement in MMP-3 levels at 12 weeks was an independent predictive factor (adjusted OR: 4.277, p=0.003) in the bio-switch group, whereas DAS28 was the only predictor in the bio-naïve group. Patients who achieved 20% improvement in MMP-3 levels at 12 weeks had significantly higher achievement rates of LDA at 52 weeks compared to those who did not achieve 20% improvement in the bio-switch group (60.0 vs. 33.3%, p=0.001).
Our findings suggest that improvement in MMP-3 levels is key to predicting the clinical efficacy of abatacept. Closer attention paid not only to major clinical indices, but also changes in MMP-3 levels, could improve our ability to optimise clinical results when treating bio-switch patients.