Effect of Concomitant Disease-modifying Antirheumatic Drugs and Methotrexate Administration Route on Biologic Treatment Durability in Rheumatoid Arthritis: OBRI Cohort Results.

OBJECTIVE: Prior studies have suggested that concurrent conventional synthetic disease-modifying antirheumatic drug (csDMARD) therapy enhances the efficacy of biologic DMARD (bDMARD). Here, we assessed the effect of concomitant csDMARD use and methotrexate (MTX) route of administration on time to bDMARD discontinuation in a large Canadian (Ontario), observational, rheumatoid arthritis (RA) cohort. METHODS: Patients from the Ontario Best Practices Research Initiative (OBRI) who initiated bDMARD therapy and had ≥ 1 followup assessment were included. The effect of concomitant csDMARD use (primary analysis) and MTX route of administration (secondary analysis) on bDMARD discontinuation owing to (1) any reason, (2) ineffectiveness, (3) adverse events (AE), and (4) both (2) and (3), were assessed with multivariate Cox regression. RESULTS: Among the 814 patients included, 153 (18.8%) received bDMARD monotherapy and 661 (81.2%) combination csDMARD/bDMARD therapy. Over a mean followup of 1.9 years, bDMARD were discontinued in 38.7% of patients. In multivariate analysis, there was a nonsignificant trend toward lower discontinuation for the csDMARD/bDMARD group compared to bDMARD monotherapy for any reason (HR 0.76, 95% CI 0.55-1.05) and owing to ineffectiveness/AE (HR 0.73, 95% CI 0.50-1.06). Further, patients taking combination therapy had significantly lower risk of bDMARD discontinuation due to AE (HR 0.43, 95% CI 0.24-0.76). In the secondary analysis, no statistical association between MTX dose or route of administration and bDMARD durability was observed. CONCLUSION: Concomitant csDMARD use was associated with a significantly lower hazard for bDMARD discontinuation due to AE among patients with RA followed in routine clinical practice in Ontario, Canada. Neither MTX route of administration nor dose were significant predictors of bDMARD durability.

Treatment patterns in rheumatoid arthritis after discontinuation of methotrexate: data from the Ontario Best Practices Research Initiative (OBRI).

OBJECTIVES: In active rheumatoid arthritis (RA) patients with inadequate response to methotrexate (MTX), guidelines support adding or switching to another conventional synthetic disease-modifying anti-rheumatic drug (csDMARD) and/or a biologic DMARD (bDMARD). The purpose of this analysis was to describe treatment practices in routine care and to evaluate determinants of regimen selection after MTX discontinuation. METHODS: Biologic-naïve patients in the Ontario Best Practice Research Initiatives registry discontinuing MTX due to primary/secondary failure, adverse events, or patient/physician decision were included. RESULTS: Of 313 patients discontinuing MTX, 102 (32.6%) were on MTX monotherapy, 156 (49.8%) on double, and 55 (17.6%) on multiple csDMARDs. Patients on MTX monotherapy were older than patients on double or multiple csDMARDs (p=0.013), less likely to have joint erosions (p=0.009) and had lower patient global assessment (p=0.046) at MTX discontinuation. Post-MTX discontinuation, 169 (54.0%) transitioned to, or added new DMARD(s) (new csDMARD(s): 139 [44.4%]; bDMARD: 30 [9.6%]), and 144 (46.0%) opted for no new DMARD treatment. Patients on MTX monotherapy transitioning monotherapy, whereas patients on combination csDMARDs switched more to new csDMARDs and bDMARD combination therapy. Early RA (adjOR [95%CI]: 3.07 [1.40-6.72]) and treatment with multiple csDMARDs vs. MTX monotherapy (4.15 [1.35-12.8]) at MTX discontinuation were significant predictors of transitioning to or adding new csDMARD(s)/bDMARD treatment versus opting for no new DMARD treatment. CONCLUSIONS: Differences in subsequent treatment patterns exist between patients discontinuing MTX when used as monotherapy versus in combination with other csDMARDs where the former are more likely to use a subsequent monotherapy treatment.