Treatment of Rheumatoid Arthritis with Certolizumab Pegol: Results from PROACTIVE, a Non-Interventional Study in the UK and Ireland

Introduction: The objective of this non-interventional study was to investigate the longterm safety and effectiveness of certolizumab pegol (CZP) in patients with rheumatoid arthritis (RA) in the UK and Ireland. Methods: Patients were prescribed CZP at their physicians' discretion and followed during routine clinical practice for up to 88 weeks. DAS28(ESR) response (defined as at least a 1.2point reduction from baseline) was measured in the full analysis set (FAS) at week 12, and patients were categorized by week 12 responder status in all subsequent analyses. The primary outcome was DAS28(ESR) response at week 78. Secondary outcomes included change from baseline in DAS28(ESR), HAQ-DI, and RADAI scores at week 78, and EULAR response at week 78. Adverse drug reactions (ADRs) were recorded for all patients who received at least one dose of CZP. Results: A total of 149 patients were enrolled, of whom 111 (74.5%) formed the FAS. At week 12, 80 patients (72.1%) were DAS28(ESR) responders and 31 (27.9%) non-responders. Compared to non-responders, a greater proportion of week 12 responders had a DAS28(ESR) response at week 78 (43.8% versus 22.6%). Improvements in DAS28(ESR), HAQ-DI, and RADAI scores were also greater on average among week 12 responders, as was the proportion of patients meeting EULAR criteria. Overall, 9 patients (6.1%) experienced 13 ADRs during the study. Conclusion: These data demonstrate the safety and effectiveness of CZP in adult patients with RA treated during routine clinical practice in the UK and Ireland.