To compare the real-life effectiveness of biologic therapy (a biologic disease-modifying antirheumatic drug plus methotrexate [MTX]) versus triple therapy (MTX plus sulfasalazine plus hydroxychloroquine/chloroquine) for sustained remission of rheumatoid arthritis (RA).
RA patients who were registered in the nationwide Swedish Rheumatology Quality Register between 2000 and 2012 and were receiving biologic or triple therapy as a first treatment strategy after MTX monotherapy were included. Sustained remission was defined as a Disease Activity Score in 28 joints (DAS28) of <2.6 for ≥6 months (short-term sustained remission) or for ≥24 months (long-term sustained remission). Treatment groups were compared during treatment, at 1 year, and at 2 years for 1) all patients starting therapy and 2) patients continuing to receive therapy, using propensity score-adjusted regression analyses. In addition, survival analyses were used to compare treatment groups at any time during follow-up irrespective of therapy retention.
A total of 1,502 patients were included (1,155 receiving biologic therapy and 347 receiving triple therapy). For patients starting therapy, the adjusted odds ratios (ORs) of achieving short-term and long-term remission, respectively, at 1 year after start of biologic therapy versus triple therapy were 1.79 (95% confidence interval [95% CI] 1.18-2.71) and 1.86 (95% CI 1.00-3.48). At 2 years, the ORs were 1.92 (95% CI 1.21-3.06) and 1.62 (95% CI 0.94-2.79), respectively. For patients continuing to receive therapy, corresponding results at 1 year were 1.12 (95% CI 0.72-1.75) and 1.1 (95% CI 0.59-2.16); at 2 years, 0.85 (95% CI 0.49-1.47) and 0.76 (95% CI 0.41-1.39). Hazard ratios for short-term and long-term sustained remission at any time during follow-up were 1.15 (95% CI 0.91-1.46) and 1.09 (95% CI 0.77-1.54), respectively.
Among patients starting biologic or triple therapy, biologic therapy was more effective for remaining on therapy and achieving sustained remission. However, similar probabilities were found for achieving sustained remission among patients remaining on therapy and at any time during follow-up irrespective of therapy retention. Although the likelihood of reaching sustained remission is higher with biologic therapy, for certain RA patients triple therapy may still be an alternative to biologic therapy without hampering future chances of obtaining sustained remission.