Introduction: This study assessed if concomitant use of conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) or corticosteroids altered the response or safety outcomes to baricitinib in rheumatoid arthritis (RA) patients.
Methods: Patients with ≥ 6 swollen/tender joints and no prior biologic DMARD were eligible for study inclusion. In RA-BUILD, csDMARD-inadequate responder (IR) patients were randomized to placebo or baricitinib (2 or 4 mg) once daily (QD). In RA-BEAM, methotrexate (MTX)-IR patients were randomized to placebo QD, baricitinib 4-mg QD, or adalimumab 40-mg biweekly. Patients continued background csDMARD (including MTX) therapy. This post hoc analysis of placebo and baricitinib 4-mg patients assessed the number and type of concomitant csDMARDS and concurrent corticosteroid use.
Results: From 716 placebo patients, 71, 21, and 6% were taking MTX alone, MTX + ≥ 1 csDMARD, and non-MTX csDMARDs, respectively; from 714 baricitinib patients, the rates were 74, 18, and 6%; 56% of placebo and 55% of baricitinib patients used corticosteroids at baseline (mean dose, 6.0 mg/day for both groups); patients continued use throughout the studies. The odds ratios for achieving American College of Rheumatology response at the 20% improvement level (ACR20) and Clinical Disease Activity Index (CDAI) ≤ 10 at week 12 favored baricitinib for most subgroups; no significant interactions were observed. Rates of adverse events were similar regardless of csDMARD group or corticosteroid use. There were numerically more serious adverse events in placebo patients taking corticosteroids (4.2 vs. 1.6%) and a higher rate of discontinuations in baricitinib patients taking corticosteroids (4.1 vs. 1.2%).
Conclusions: Baricitinib was efficacious regardless of concomitant use of csDMARDs or corticosteroids; the incidence of adverse events was similar across all groups of patients.
Funding: Eli Lilly and Company and Incyte Corporation.
Keywords: Corticosteroids; DMARDs; Rheumatoid arthritis.