Early non-response to certolizumab pegol in rheumatoid arthritis predicts failure to achieve low disease activity at 1 year: data from a prospective observational study

Objective To evaluate the performance of clinical criteria for predicting late treatment failure in patients with early non-response to certolizumab pegol (CZP). Methods A protocol-specified analysis of interim data from ECLAIR, a 3-year longitudinal, prospective, observational, multicentre study of patients with active rheumatoid arthritis (RA) initiating CZP treatment in France, was conducted. Clinical measures assessed were Clinical Disease Activity Index (CDAI), Disease Activity Score-28 with erythrocyte sedimentation rate (DAS28(ESR)) and Health Assessment Questionnaire Disability Index (HAQ-DI). Early non-response was measured at 3 months (M3) and failure to achieve low disease activity (LDA) at 12 months (M12). Results 574/792 enrolled patients were treated at M3. The numbers available for predictability analyses were 532 (CDAI), 434 (DAS28(ESR)) and 496 (HAQ-DI). Of the three indices evaluated, the highest predictor of non-response value was observed for the CDAI (88.8% (95% CI 81.0 to 94.1)), indicating that up to 88% of patients identified as non-responders at M3 failed to achieve LDA at M12, regardless of baseline disease severity or treatment history. The specificity for this measure was also very high (96.0%), indicating that less than 5% of patients who achieved CDAI response at M12 had not responded at M3. Similar predictability was observed for DAS28(ESR), but only in patients with high disease activity at baseline and/or those previously treated by a biological disease-modifying antirheumatic drug. Conclusion CDAI non-response at M3 is a predictor of failure to achieve the therapeutic target of LDA at M12 in patients with RA initiating treatment with CZP.