Baricitinib: Well-Tolerated, Effective Long-Term Treatment for Moderate to Severe Rheumatoid Arthritis

Once-daily 4 mg baricitinib was well-tolerated and effective for treating moderate-to-severe rheumatoid arthritis (RA) over a 3-year period, according to study findings published in Rheumatology.

The study was an analysis of pooled data from 2 completed 52-week phase 3 studies as well as an ongoing long-term extension study. In the RA-BEGIN study (Clinicaltrials.gov Identifier: NCT01711359), patients with no history of disease-modifying anti-rheumatoid drugs (DMARDs) use who were treated with either methotrexate-immediate release (MTX) or 4mg baricitinib plus MTX-IR were switched to open-label 4 mg baricitinib monotherapy at week 52.

In the RA-BEAM study (Clinicaltrials.gov Identifier: NCT01710358), patients originally received either once-daily baricitinib 4 mg, adalimumab subcutaneously every 2 weeks, or placebo while continuing MTX therapy. At week 24, patients having an inadequate response to MTX (MTX-IR) and placebo were switched to open-label 4 mg baricitinib; 4 mg baricitinib was also given to any treatment group at week 16 as a rescue therapy. Patients in the 2 studies were also switched to open-label 4 mg baricitinib monotherapy or 4 mg baricitinib with MTX in the long-term extension study.

The investigators assessed changes in low disease activity (LDA) using the Simple Disease Activity Index (SDAI) of 11 or less, clinical remission (SDAI ≤3.3), and physical functioning using the Health Assessment Questionnaire Disability Index (HAQ-DI) of 0.5 or less.

By week 148, SDAI LDA was achieved in approximately 61% of DMARD-naïve patients and 59% of MTX patients who initially received baricitinib. Additionally, SDAI remission was achieved in 34% of DMARD-naïve patients and 24% of MTX-IR patients; HAQ-DI of 0.5 or less was reached in up to 48% of DMARD-naïve patients and 38% of MTX-IR patients who initially received baricitinib.

Discontinuation of therapy reported in 3.6% of MTX-IR patients for lack of efficacy and 10.7% of MTX-IR patients for adverse events. Similar discontinuation rates were observed in the DMARD-naïve population.

A limitation of this study included the lack of long-term data comparisons between groups, which was due to insufficient statistical power for the analysis.

Based on these findings, this study suggests “baricitinib 4 mg may be considered for long-term treatment of early and refractory” RA, the study authors concluded.

Disclosure: This clinical trial was supported by Eli Lilly. Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.

Reference

Smolen JS, Xie L, Jia B, et al. Efficacy of baricitinib in patients with moderate-to-severe rheumatoid arthritis with 3 years of treatment: results from a long-term study. Rheumatology (Oxford). Published online November 17, 2020. doi:10.1093/rheumatology/keaa576