A long-term study published in Rheumatology (Oxford) has confirmed the efficacy of baricitinib in patients with moderate-to-severe rheumatoid arthritis (RA) who had inadequate responses to methotrexate (MTX), conventional synthetic DMARDs (csDMARDs), or biologic DMARDs (bDMARDs). Data from three phase III studies, RA-BEAM, RA-BUILD, and RA-BEACON, and the long-term extension study RA-BEYOND, were analyzed over a treatment period of up to 6.5 years.
At week 340 for RA-BEAM or week 336 for RA-BUILD and RA-BEACON, low disease activity (LDA) was achieved in 37% of patients with an inadequate response to methotrexate (MTX-IR), 35% of those with an inadequate response to conventional synthetic DMARDs (csDMARD-IR), and 23% of patients with an inadequate response to biologic DMARDs (bDMARD-IR), according to non-responder imputation (NRI). Completer analyses showed even higher LDA rates, with 83% in both the MTX-IR and csDMARD-IR groups, and 73% in the bDMARD-IR group. Clinical remission was observed in 20%, 13%, and 9% of these groups, respectively, based on NRI analysis, with higher remission rates in completer analysis. Physical function, as measured by HAQ-DI, improved in 31% of MTX-IR, 25% of csDMARD-IR, and 24% of bDMARD-IR patients. The study also confirmed that baricitinib was well-tolerated over the long term, with relatively low discontinuation rates due to adverse events, death, or lack of efficacy.
Baricitinib, an oral selective Janus kinase (JAK) 1/2 inhibitor, is approved for treating adults with moderate-to-severe RA, atopic dermatitis, severe alopecia areata, and hospitalized COVID-19 patients. It works by inhibiting Janus kinases, preventing the activation of signaling pathways that drive gene expression. Specifically, these kinases activate the STAT pathway, initiating a cascade that leads to the transcription of effector genes. This process triggers the autoimmune and inflammatory responses responsible for the main symptoms of RA. Baricitinib has shown efficacy in both treatment-naive RA patients and those with an inadequate response to biologic DMARDs, conventional synthetic DMARDs, and methotrexate.
The results from this extensive 6.5-year study validate the efficacy of baricitinib as a long-term treatment for moderate-to-severe rheumatoid arthritis. Whether in patients with an inadequate response to MTX, csDMARDs, or bDMARDs, baricitinib has consistently demonstrated its ability to maintain low disease activity, promote clinical remission, and improve physical function. Furthermore, the favorable safety profile supports its use as a durable option for managing RA over the long term. For rheumatologists treating patients with RA who have struggled with other treatment options, baricitinib offers a promising solution, backed by robust data from one of the longest studies of its kind.
References
- Caporali R, Taylor PC, Aletaha D, Sanmartí R, Takeuchi T, Mo D, et al. Efficacy of baricitinib in patients with moderate-to-severe rheumatoid arthritis up to 6.5 years of treatment: results of a long-term study. Rheumatology (Oxford). 2024 Oct 1;63(10):2799-2809.
- Urits I, Israel J, Hakobyan H, Yusin G, Lassiter G, Fackler N, Berger AA, Kassem H, Kaye A, Viswanath O. Baricitinib for the treatment of rheumatoid arthritis. Reumatologia. 2020;58(6):407-415.