Efficacy and Safety of Biologics in Polymyalgia Rheumatica: A Retrospective Study

Introduction: The study aimed to determine the efficacy and safety of biological disease-modifying antirheumatic drugs (bDMARDs) in the treatment of polymyalgia rheumatica (PMR) complicated by rheumatoid arthritis (RA).

Methods: Patients with PMR which could be classified as RA and who were treated with bDMARDs were included in the analysis. The primary endpoint was the clinical Polymyalgia Rheumatica Activity Score (Clin-PMR-AS) after 26 weeks of treatment, and the secondary endpoint was adverse events during the observation period.

Results: A total of 203 patients with PMR which was resistant or intolerant to glucocorticoids and could be classified as RA were receiving bDMARDs and were enrolled in the study. There were 83, 82, and 38 patients in the tumor necrosis factor inhibitor (TNFi), interleukin-6 receptor inhibitor (IL-6Ri), and cytotoxic T lymphocyte-associated antigen-4-immunoglobulin (CTLA4-Ig) groups, respectively. Twenty-six weeks after bDMARD initiation, Clin-PMR-AS levels were significantly lower in the IL-6Ri group as compared to other groups. Multiple regression analysis was performed with Clin-PMR-AS as the objective variable. Body mass index (BMI), history of bDMARDs, and IL-6Ri use were identified as factors involved in Clin-PMR-AS. After adjustment for group characteristics using inverse probability of treatment weighting with propensity scores, the Clin-PMR-AS score at 26 weeks was significantly lower in the IL-6Ri group (9.0) than in both the TNFi (12.4, p = 0.004) and CTLA4-Ig (15.9, p = 0.003) group.

Conclusion: IL-6Ri may potentially improve the disease activity of PMR compared to other bDMARDs.