For patients with rheumatoid arthritis (RA), using conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) concomitantly with biologic DMARDs (bDMARDs) is associated with a significantly reduced risk for bDMARD discontinuation because of adverse events (AEs), according to results published in the Journal of Rheumatology.
The study included participants from the Ontario Best Practices Research Initiative (OBRI) who initiated bDMARD therapy and had ≥1 follow-up assessment (n=814). The researchers assessed the effect of concomitant csDMARD use and methotrexate (MTX) route of administration on bDMARD discontinuation for any reason, ineffectiveness, AEs, and both ineffectiveness and AEs using multivariate Cox regression.
Of 814 participants, 18.8% (n=153) received bDMARD monotherapy and 81.2% (n=661) received combination csDMARD/bDMARD therapy. Over a mean follow-up of 1.9 years, 38.7% of participants discontinued bDMARDs.
Using multivariate analysis, the researchers found a nonsignificant trend toward lower discontinuation rates in the combination therapy group compared with the bDMARD monotherapy group for any reason (hazard ratio [HR], 0.76; 95% CI, 0.55-1.05) and because of ineffectiveness/AE (HR, 0.73; 95% CI, 0.50-1.06).
The results indicated that participants in the combination therapy group had a significantly lower risk for bDMARD discontinuation because of AEs compared with those in the monotherapy group (HR, 0.43; 95% CI, 0.24-0.76).
The researchers did not find any statistical association between MTX dose or route of administration and bDMARD durability.
“Overall, these results support the use of bDMARD in combination with csDMARD among patients with active RA, and suggest that either oral or subcutaneous MTX is appropriate when used in combination with a bDMARD,” the researchers wrote.
Lau AN, Thorne JC, Movahedi M, et al. Effect of concomitant disease-modifying antirheumatic drugs and methotrexate administration route on biologic treatment durability in rheumatoid arthritis: OBRI cohort results. [published online April 15, 2019]. J Rheumatol. doi:10.3899/jrheum.180486