Assessing Trends and Outcomes of Baricitinib Use in Severe RA

Based on real-world data, a high percentage of patients with severe rheumatoid arthritis (RA) continued to receive treatment with baricitinib at 6 and 12 months, and overall, had lower disease activity, according to findings of a study published in Rheumatology.

The aim of the study was to evaluate trends in baricitinib-associated use and outcomes between 2018 and 2020 among individuals enrolled in the British Society for Rheumatology Biologics Registry-RA (BSRBR-RA) registry.

Remission was defined as a disease activity score-28 for RA with erythrocyte sedimentation rate (DAS28-ESR) of less than 2.6 points; low disease activity (LDA) was a score of greater than 2.6 to 3.2 points; moderate disease activity (MDA) was a score of greater than 3.2 to 5.1 points; and high disease activity (HDA) was a score of greater than 5.1 points.

The study population included 561 patients, among whom 76.5% were women, with a median age of 61.1 years and a mean RA duration of 13.1±10.3 years.

With regarding to dosing, the majority of the cohort (85.2%) received an initial baricitinib dose of 4 mg and 60.6% received treatment with baricitinib plus a conventional synthetic disease-modifying antirheumatic drug (csDMARD).

The median DAS28-ESR score at baseline was 5.7 (IQR, 5.2-6.4) points and at 6 months, it was 3.2 (IQR, 2.2-4.2) points. Similar baseline and 6-month scores were observed across subgroups. The lowest score at 6 months was observed in the subset of patients who were biologic or targeted synthetic DMARD (b/tsDMARD)-naive (median, 2.7 points).

At baseline, 2.3% of patients were in DAS28-ESR-remission, 1.4% had LDA, 18.6% had MDA, and 77.6% had HDA. At 6 months, among 265 patients with available data, the rates were 35.4%, 13.7%, 37.1%, and 13.7%, respectively.

At the 6-month follow-up, 77.7% of the cohort continued to use baricitinib. Stratified by subgroups, the continuation rate was greater than 70% for all groups, ranging from 70.5% among those who received 2 mg baricitinib to 84.3% among those who were b/tsDMARD-naive.

At 12 months, the continuation rate was 69.1%, and stratified by subgroup, it ranged between 52.6% among 2 mg baricitinib recipients to 76.6% among baricitinib-monotherapy recipients.

At both 6 and 12 months, the most common reasons for treatment discontinuation were adverse events (62.5%-63.2%), lack of efficacy (24.6%-25.0%), and other reasons (12.3%-12.5%).

A major limitation of the study was the loss of participants to follow-up.

The study authors concluded, “It is notable that baricitinib performed well as monotherapy, providing a therapeutic option for patients unable to tolerate csDMARDs.”

Disclosure: This research was supported by Eli Lilly and Company. Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.