OBJECTIVES

This study describes outcomes at 6 months among RA patients receiving infliximab and its biosimilars in US community rheumatology practices.

METHODS

The study used electronic medical records from the American Rheumatology Network (ARN) - Trio Health Rheumatology registry. The ARN is a physician-led and owned organization with 200+ practicing rheumatologists in the US. Patients with RA diagnosis who initiated or switched to infliximab or biosimilars since Dec’2016 were selected for analysis. Logistic regression (LR) was used to evaluate binary outcome remission/low disease activity at 6 months (vs moderate/high) accounting for patient characteristics (age, payer, regimen, steroid use, number of prior regimens, and baseline disease activity).

RESULTS

Of 2806 patients, 1972 (70%) received infliximab and 834 (30%) biosimilars: infliximab-dyyb (69%) or infliximab-abda (31%). Compared to those on biosimilars, infliximab patients had significantly (p<.001) fewer prior synthetic disease-modifying antirheumatic drugs (DMARDs) or biologic regimens (mean regimens 1.4 (SD 1.8) vs 2.2 (1.9) infliximab-dyyb, 2 (1.6) infliximab-abda), were less likely to be Medicaid insured (4% vs 8% infliximab-dyyb, 24% infliximab-abda), were more likely to be in remission/low disease activity at treatment initiation (66% vs 43% infliximab-dyyb, 43% infliximab-abda) and at 6 months since treatment initiation (75% vs 60% infliximab-dyyb, 56% infliximab-abda).

In LR variables significantly associated the outcome were baseline disease activity (high/moderate vs low/remission: adjusted odds ratio (OR)=.09 CI .07-.14), payer type (Medicaid vs commercial: OR=.47 CI=.22-.99, and use of steroids (OR=.56 CI .40-.79) but not choice of a biologic (infliximab-abda vs infliximab OR=.91 CI .49-1.69, infliximab-dyyb vs infliximab OR=1.11 CI .74-1.65).

CONCLUSIONS

After accounting for patient characteristics, regimen choice was not significantly associated with treatment success at 6 months since regimen initiation.