Clinical Edge Journal Scan Commentary: RA March 2022

Arundathi Jayatilleke, MD

The recent ORAL Surveillance trial has raised concerns about the safety of tofacitinib (and potentially other JAK inhibitors) in the treatment of rheumatoid arthritis. ¹ JAK inhibitors are known to increase cholesterol levels; however, this was not previously known to increase cardiovascular risk. The ORAL Surveillance trial was an open-label randomized non-inferiority trial comparing 5mg or 10 mg tofacitinib twice daily with tumor necrosis factor (TNF) inhibitor use. Both adverse cardiac events and cancer were increased in the tofacitinib groups (with hazard ratios of 1.33 and 1.48, respectively). The study did not include a control group and so the impact of RA itself on cardiac events and cancer is not known. However, the apparent risk was greatest in patients over the age of 65, suggesting caution should be used in treating older patients with RA with JAK inhibitors. Interestingly, the STAR-RA study, an observational cohort study, looked at claims data from several sources to try to replicate trial results as well as provide real-world evidence on the topic of cardiovascular risk associated with tofacitinib use. ² The authors were able to replicate the inclusion/exclusion criteria from the ORAL Surveillance trial and found that the results were similar. However, on “relaxing” inclusion and exclusion criteria, ie, the “real-world evidence” cohort, there was no difference in incidence of cardiovascular outcomes between tofacitinib and TNF-inhibitor groups. Specifically, patients in the real-world cohort who had no cardiovascular risk factors or prior events were not found to have an increased cardiovascular risk with tofacitinib use, a reassuring finding supporting careful attention to cardiovascular risk in patients with RA when evaluating treatment options.

One consideration in the use of rituximab for treatment of RA is the possibility of changing or lowering subsequent or maintenance doses. Past studies have suggested that halving the dose of rituximab to a single 1000 mg infusion was tolerated by RA patients. The REDO trial, published in 2019, looked at even lower doses: 500 mg and 200 mg. The study did not establish non-inferiority of lower doses at 6 months in a per-protocol analysis, only in intention-to-treat. An extension study of REDO presented at the ACR Convergence in 2021 looked at a subset of those patients for up to 4 years and did find non-inferiority in terms of disease activity. Wientjes et al ³ present further analysis of the REDO trial with 140 RA patients at 6 months, looking at the association of rituximab dosage with B cell counts as well as the predictive value of different patient characteristics in terms of response to lower dosages. Interestingly, serum drug levels and B cell counts at 3 and 6 months did not predict response to rituximab, nor did patient characteristics, such as age, smoking, disease, duration, or seropositivity for RF and CCP. Though the authors suggest that this implies even lower doses may be effective, it is not clear, and a similar analysis of the extension trial would be of interest.

Use of methotrexate as a first-line DMARD for RA is cost-effective but often limited by patient fears or intolerance due to adverse events (AE). This observational cohort study by Sherbini et al ⁴ evaluates not only the prevalence of AE, but also baseline factors that may predict the development of AE. Over 1,000 patients with early RA initiating methotrexate were included in analysis. More than 75% reported at least one AE in 12 months, with gastrointestinal AE, such as nausea, being most prevalent (42%); 18% developed elevated liver enzyme tests (defined as a single reading above the upper limit of normal). Few strong predictors of AE were identified, though women were overall more likely than men to report AE. Reassuringly, combination conventional synthetic DMARD therapy did not generally lead to more reported AE. Given the few predictive findings from this study, analysis of a comparator group or comparison of AE at different starting and maintenance doses of methotrexate would be of interest.

References

1. Ytterberg SR et al . Cardiovascular and cancer risk with tofacitinib in rheumatoid arthritis. N Engl J Med. 2022;386:316-326 (Jan 27).
2. Khosrow-Khavar F et al. Tofacitinib and risk of cardiovascular outcomes: results from the Safety of TofAcitinib in Routine care patients with Rheumatoid Arthritis (STAR-RA) study. Ann Rheum Dis. 2022 (Jan 13).
3. Wientjes MHM et al. Drug levels, anti-drug antibodies and B-cell counts were not predictive of response in rheumatoid arthritis patients on (ultra-)low-dose rituximab. Rheumatology (Oxford). 2022 (Jan 12).
4. Sherbini AA et al. Rates and predictors of methotrexate-related adverse events in patients with early rheumatoid arthritis: results from a nationwide UK study. Rheumatology (Oxford). 2022 (Jan 25).