To evaluate the effectiveness of select biologics, methotrexate (MTX), and other disease-modifying anti-rheumatic drugs (DMARDs) in the management of adult rheumatoid arthritis (RA) in routine clinical practice.
RADIUS (Rheumatoid Arthritis DMARD Intervention and Utilization Study) comprises two prospective, 5-year, observational registries of over 10 000 patients. Over 4600 patients who initiated MTX or a biologic regimen (etanercept [ETN], infliximab [INF], ETN + MTX, and INF + MTX) and who had at least one on-regimen, follow-up evaluation, were included in this analysis. Adalimumab was not included because it had not yet received FDA approval at RADIUS initiation. Other common DMARD regimens (N = 762) were also compared with MTX. Patients who initiated less commonly used regimens, such as anakinra or cyclosporine, and those who did not have at least one on-regimen, follow-up evaluation, were not eligible for this analysis. Because ESR/CRP measurements were often not available, a modified ACR20 response (mACR20), defined as three out of four response criteria excluding ESR/CRP, was used to assess response at 12 months. Logistic regression analysis was performed to control for baseline covariates that may affect outcomes.
The primary endpoint was the proportion of patients who achieved a mACR20 response at 12 months post-RADIUS entry.
After adjusting for baseline covariates, patients receiving either ETN + MTX or ETN monotherapy were more likely to achieve a mACR20 response at 12 months than patients receiving MTX alone (odds ratio [OR] 1.29, 95% confidence interval [CI] 1.09-1.52; p < 0.01 and OR 1.23, 95% CI 1.02-1.47; p < 0.05, respectively). Conversely, patients treated with MTX + leflunomide (LEF) were less likely to achieve a mACR20 response than those receiving MTX alone (OR 0.68, 95% CI 0.48-0.96; p < 0.05). Significant differences were not observed between patients receiving MTX alone and either INF + MTX, MTX + hydroxychloroquine, MTX + hydroxychloroquine + sulfasalazine, INF monotherapy, or LEF monotherapy.
These data from routine rheumatology clinical practice settings highlight the effectiveness of common biologic and DMARD therapies, and provide additional data beyond those of randomized, controlled trials.