Real-World Study Sheds Light on Effects, Adherence to Baricitinib in Rheumatoid Arthritis

Rosario García-Vicuña, MD
Credit: LinkedIn

A new study from investigators in Europe is offering insight into the real-world effects of baricitinib (Olumiant) use in the management of rheumatoid arthritis (RA).

Results of the study, which enrolled more than 60 patients with RA, suggest use of baricitinib demonstrated effectiveness, durable persistence, high adherence to treatment, and an acceptable safety profile in real-world settings.¹

“The main findings in our study were the high rates of effectiveness, persistence, and adherence of [baricitinib] in a long-standing and mostly bDMARD experienced population with a significant proportion of seropositivity and erosive disease; nonetheless, biologic-naive patients achieved a better response to [baricitinib] treatment,” wrote investigators.¹

As cited by investigators, baricitinib was the first oral selective Janus kinase inhibitor approved in Europe for RA. In the US, baricitinib received approval in July 2018 and holds the total of second oral JAK inhibitor approved for RA, with the first approval going to tofacitinib (Xeljanz) in November 2012. Among the stipulations associated with the approval from the US Food and Drug Administration was the requirement for further study to assess the long-term safety and efficacy of the agent.^1,2

To better understand the real-world use and effects of oral JAK inhibitors in patients with RA, a team led by Rosario García-Vicuña, MD, of the Autonomous University of Madrid, designed a longitudinal ambispective chart review of patients who received baricitinib at La Princesa University Hospital in Madrid between October 2017 and June 2021. The investigators definedindex date as the first baricitinib prescription date and the follow-up was defined as the period between the index date and death, loss to follow-up, or last chart review data. For inclusion, patients needed to be 18 years of age or older and diagnosed with RA using the ACR/EULAR 2010 classification criteria.¹

The primary outcome of interest was the effectiveness of baricitinib. Secondary outcomes of interest included effects on treatment persistence, treatment adherence, and safety.¹

For the purpose of analysis, efficacy was assessed as changes from baseline in Disease Activity Score using 28-joint counts-C reactive protein (DAS28CRP), and the achievement of low disease activity/remission. Investigators assessed adherence using medication possession ratio (MPR) and the 5-item Compliance Questionnaire for Rheumatology. Additionally, Kaplan-Meier analyses were used to evaluate drug persistence and safety was expressed by determining global incidence proportion and adverse event adjusted incidence rates.¹

Among 64 patients who were recruited for the study, 61 were included in the final analysis. This cohort was 83.6% were female, 78.7% were seropositive, the mean age at initiation of baricitinib was 58.1 (Standard Deviation [SD], 15.4) years, the mean disease duration was 13.9 (SD, 8.3) years, and the median exposure to baricitinib was 12.4 (range, 3.1 to 51.4) months. When assessing treatment history, investigators found 32.8% of patients had no prior exposure to biologics, 49.1% reported previous exposure to glucocorticoid treatment, and 16.4% were using baricitinib as a monotherapy.¹

Upon analysis, results suggested use of baricitinib was associated with a significant change in DAS28CRP (difference −1.2; P = .0000), with 70.5% and 60.7% of patients achieved low disease activity or remission, respectively. Further analysis revealed that 50.8% of patients remained on baricitinib throughout the follow-up, with a median treatment persistence of 31.2 (95% Confidence interval 9.3 to 53.1) months observed in the trial. Investigators pointed out the mean MPR in the study was 0.96 (SD, 0.08) and all patients exhibited “good adherence” according to questionnaire data.¹

Safety analyses revealed the most prevalent adverse events among the cohort were anemia (39.3%), infection (36.1%), hypercholesterolemia (32.8%), and abnormal liver enzymes (31.1%). Overall, 21.3% of patients discontinued baricitinib due to toxicity and 0 deaths were reported in the study.¹

Investigators noted several limitations within their study to consider when interpreting results. These limitations included use of a non-interventional, ambispective design, use of a limited sample size, limited generalization due to the single-center nature of the study, and lack of information related to smoking status, body mass index, or other confounding variables that could interfere with the therapeutic response.¹

“In this real-world study, [baricitinib] was mainly used in patients with moderate, erosive, seropositive, long-standing RA, previously exposed to more than one b/tsDMARDs. These characteristics have been associated with more severe disease and a greater difficulty in reaching the therapeutic target,” investigators wrote.¹ “Despite this, [baricitinib] can provide significant benefits in several outcomes in RA patients, even in those with long-standing, severe, and refractory disease. However, patients without previous exposure to biologics appear to benefit more from the drug.”

References:

1. Calvo-Garcia A, Ramírez Herráiz E, Llorente Cubas IM, et al. The Real-World Effectiveness, Persistence, Adherence, and Safety of Janus Kinase Inhibitor Baricitinib in Rheumatoid Arthritis: A Long-Term Study. J Clin Med. 2024;13(9):2517. Published 2024 Apr 25. doi:10.3390/jcm13092517
2. Anderson LA. Which jak inhibitors are approved in the U.S? Drugs.com. December 6, 2023. Accessed May 16, 2024. https://www.drugs.com/medical-answers/jak-inhibitors-approved-3575793/.