Clinical and immunological effects of hydroxychloroquine in patients with active rheumatoid arthritis despite antirheumatic treatment

Objectives: To investigate the efficacy and safety of hydroxychloroquine (HCQ) in patients with rheumatoid arthritis (RA). Methods: Patients with active RA, despite conventional synthetic disease-modifying antirheumatic drugs (csDMARDs), were recruited. HCQ was administered for 24 weeks, in addition to prior treatment. The primary end-point was the proportion of patients achieving American College of Rheumatology (ACR) 20 at Week 24, compared to that of a propensity score–matched historical control group. Results: Sixty patients were enrolled and administered HCQ. We also identified 276 patients as candidates for the historical control group. Propensity score matching yielded 46 patients in each group. The proportion of patients achieving ACR20 at Week 24 was significantly higher in the HCQ group than in the control group (54.4% vs. 28.3%, P = .007). The proportion of patients achieving ACR50 and ACR70 at Week 24 were also higher in the HCQ group than in the control group (ACR50, 30.4% vs. 4.3%, P = .006; ACR70, 17.4% vs. 0%, P = .005). Neither HCQ retinopathy nor any new safety signal was observed during the study. Conclusion: The addition of HCQ to csDMARDs was effective, with no new safety signal in patients with RA.