Efficacy of baricitinib in patients with moderate-to-severe rheumatoid arthritis up to 6.5 years of treatment: results of a long-term study

OBJECTIVES: To evaluate the long-term efficacy of once-daily baricitinib 4 mg or 2 mg in patients with active rheumatoid arthritis who had inadequate response (IR) to MTX, csDMARDs or bDMARDs. METHODS: Data from three completed phase III studies-RA-BEAM (MTX-IR), RA-BUILD (csDMARD-IR) and RA-BEACON (bDMARD-IR)-and one completed long-term extension study (RA-BEYOND) were analysed up to 6.5 years 340 weeks (RA-BEAM) and 336 weeks (RA-BUILD and RA-BEACON). Low disease activity (LDA) Simplified Disease Activity Index (SDAI) ≤11, clinical remission (SDAI ≤3.3) and physical function Health Assessment Questionnaire Disability Index (HAQ-DI) ≤0.5 were the main outcomes assessed. Completer and non-responder imputation (NRI) analyses were conducted on each population. RESULTS: At week 340 or 336, LDA was achieved in 37%/83% of MTX-IR, 35%/83% of csDMARD-IR and 23%/73% of bDMARD-IR patients treated with baricitinib 4 mg, assessed by NRI/completer analyses, respectively. Remission was achieved in 20%/40% of MTX-IR, 13%/32% of csDMARD-IR and 9%/30% of bDMARD-IR patients treated with baricitinib 4 mg, assessed by NRI/completer analyses, respectively. HAQ-DI ≤0.5 was reached in 31%/51% of MTX-IR, 25%/46% of csDMARD-IR and 24%/38% of bDMARD-IR patients treated with baricitinib 4 mg, assessed by NRI/completer analyses, respectively. CONCLUSION: Treatment with baricitinib 4 mg or 2 mg demonstrated efficacy up to 6.5 years with maintained LDA/remission results across SDAI, CDAI and DAS28-hsCRP consistent with previously reported data, and was well tolerated. TRIAL REGISTRATION: United States National Library of Medicine clinical trials database www.clinicaltrials.gov; RA-BEYOND; NCT01885078.