ABSTRACT
Background/Aims Tofacitinib and baricitinib were the first orally available, targeted synthetic Janus kinase (JAK) inhibitors approved for the treatment of rheumatoid arthritis (RA) in the UK. Evidence suggests that JAK inhibitors are as efficacious as biological DMARDs in the treatment of RA. Their safety profile has been demonstrated in long term extension studies and RCTs. However, real-world, long-term data remains as important in bridging the gap between controlled studies and routine practice. We report our initial real-world experience of a cohort of RA patients commenced on JAKi before the SARS-CoV-2 pandemic within a regional centre in the UK. Methods All patients commenced on JAKi for the treatment of RA between February 2018 and March 2020 were identified from our in-house database. Data was retrospectively collected from clinical notes and electronic health records from February 2018 up until April 2022. This included patient demographics, disease duration, serological status, concurrent csDMARD usage, history of bDMARD exposure, duration of use and reason for discontinuation of the drug if appropriate. DAS- 28 scores were recorded at baseline and quarterly. SPSS (version 22.0) was used for data analysis. Results One hundred thirty patients were treated with JAK inhibitors (Tofacitinib 22%, Baricitinib 78%);80% female, mean (S.D.) age 61.5 (12.3) years. 92 (70.8%) patients were seropositive. 70 (53.8%) patients were on concurrent csDMARDs and 23 (17.7%) on concurrent steroids. The mean number of previous bDMARDs was 1.8 +/- 1.7;41 (31.5%) were bDMARD naive. The mean baseline DAS-28 ESR (S.D.) score was 5.96 (0.96). There were significant differences in mean DAS- 28 ESR scores (compared with baseline) of 1.54, 1.96, 2.41, 2.33 and 1.80 at 3, 6, 12, 18 and 24 months respectively (p<0.0001). Mean DAS-28 ESR scores were not statistically significant between bDMARD naive patients and those that had previously received bDMARDs. Overall JAKi retention rate was 66.9% with a mean follow up duration of 27.4+/-13.1 months. Persistence was 88.5%, 76.9%, 73.2% and 68.5% at 6, 12, 18, and 24 months, respectively. Of the 38 patients who stopped JAK inhibitors, 11 stopped due to inefficacy (6, primary inefficacy). 3 patients were lost to follow-up and 6 deceased. Cause of death was sepsis (2), venous thromboembolism (1) and unknown (3). 18 patients stopped because of adverse events (AEs). The most common AEs were recurrent infections (11), gastrointestinal side effects (9), lymphopenia (7), thromboembolic events (6) and herpes zoster (5). In total 6 (4.1%) patients had thromboembolic events which included pulmonary embolism (4) and deep vein thrombosis (1) and central retinal artery thrombosis (1). Conclusion JAK inhibitors in this real-world population of RA patients were effective in reducing disease activity and patients had high persistence rates. Recurrent infections, herpes zoster and thrombo-embolism remain adverse events of concern.