Arundathi Jayatilleke, MD
Despite the improved outcomes in rheumatoid arthritis (RA) observed in clinical trials from early use of biologic disease-modifying antirheumatic drugs (bDMARD) in a treat-to-target strategy, real-world use may be limited by stopping medications for various reasons. Burkard and colleagues used the Swiss RA registry to examine potential reasons for discontinuation of bDMARD and targeted synthetic disease-modifying antirheumatic drugs (tsDMARD) among over 2500 adults with RA who stopped these medications from 1999 through 2018. In this cohort study, patients were followed from date of discontinuation of their medication until restarting a bDMARD or tsDMARD. The most common reasons for discontinuation were nonresponse and adverse events; of these patients, over 80% restarted a bDMARD or tsDMARD. Only 8% of patients stopped due to remission; of these, nearly half restarted. The authors found a higher proportion of fibromyalgia among patients who stopped due to nonresponse and adverse events vs due to remission. Oddly, though 40%-50% of patients stopped for "unknown reasons" between 2002 and 2006, this proportion dropped to close to 0 after 2010; during the first time period, the proportions stopping medication due to adverse events and nonresponse were also low, suggesting possible misattribution of the reason for treatment cessation. As such, drawing further conclusions on association of different patient characteristics with reasons for treatment cessation is difficult.
The gap between control of inflammatory joint pain in RA and overall patient outcomes has come up frequently in recent studies. Gwinnutt and colleagues looked at patients participating in three European RA registries, comprising over 2500 patients followed over 8-10 years, and classified them as having high or low inflammation on the basis of Disease Activity Score (DAS28) and analyzed Health Assessment Questionnaire (HAQ) score trajectories as low vs high as a measure of disability. Overall, patients in the three registries had different trajectory patterns, though it appears clear, in keeping with other studies, that a subset of patients remain with high HAQ scores despite decreases in DAS28 scores. Older age; being a woman; and more pain, fatigue, and depressive symptoms were associated with higher HAQ trajectory in both the high and low inflammation pairs, suggesting that this phenomenon is not quite "excess disability" solely in patients with low inflammation.
An additional factor that increases morbidity as well as mortality in RA is frailty, which is associated with age as well as with RA (including people < 65 years old). Hanlon and colleagues examined the change in the "frailty phenotype" over time and its association with adverse clinical outcomes in people with early RA in the Scottish Early Rheumatoid Arthritis (SERA) and UK Biobank cohorts. Frailty was defined by different measures in the two cohorts, including elements of the HAQ disability index for SERA and self-reported fatigue, depression, and poor health for UK Biobank. The computed frailty index was higher in people with higher DAS28 scores and increased with age. Of note, frailty index values were higher prior to treatment initiation and improved somewhat with lower disease activity over time, though those with higher baseline frailty index values tended to have poorer physical function and disease activity over time. Understanding frailty in RA may allow us to better predict and prevent functional limitation, disease progression, and mortality in people with RA.
Of current interest is an observational study by van der Togt and colleagues on the response to COVID-19 vaccines in people with RA being treated with rituximab. Of patients who had previously been treated with 200, 500, or 1000 mg of rituximab prior to COVID-19 vaccination, those who received 200 mg rituximab as well as those who had longer intervals between rituximab dose and vaccination had a better response to vaccination as defined by immunoglobulins (total, IgG, and IgM) against SARS-CoV-2. Although this study lacked a control arm of people being treated with other disease-modifying antirheumatic drugs and did not evaluate COVID-19 infections or outcomes, its findings do suggest that dosage and timing of rituximab in people with RA should be studied further in regard to vaccine response and infection risk.