Arundathi Jayatilleke, MD
In keeping with other studies suggesting that lower-than-standard doses of rituximab (for example, two 500 mg doses every 6 months) are effective in the treatment of rheumatoid arthritis (RA), Bertsias and colleagues evaluated the efficacy of low-dose rituximab (1 g every 6 months) in a cohort of patients with RA. Of 361 patients in the initial registry, 81 achieved sustained low disease activity or remission on standard rituximab regimens and were transitioned to the low-dose regimen; their outcomes were compared with the 280 patients in the registry who received a standard-dose regimen. Only 7.5% experienced flares of RA (compared with 5.9% in the standard-dose group), and patients in the low-dose group had fewer serious adverse events, infections, and hospitalizations. Tapering biologic disease-modifying antirheumatic drugs (DMARD) may thus be a reasonable strategy for some patients with RA, with an eye to their prior results with the medication.
The prospect of achieving sustained DMARD-free remission (SDFR) in people with RA has seemed increasingly feasible in recent studies, although it seems to be affected by anti-citrullinated protein/peptide antibody (ACPA) positivity. That is, people who are ACPA-negative are more likely to reach this target. Verstappen and colleagues examined MRI patterns of joint inflammation in the Leiden Early Arthritis Clinic cohort, as well as another cohort of patients with RA, but only included patients with an RA duration > 1 year to reduce the likelihood of misclassification. Interestingly, ACPA-positive patients who achieved SDFR tended to have lower baseline evidence of joint inflammation (including erosions, synovitis, and osteitis), which was persistent throughout follow-up, whereas ACPA-negative patients who achieved SDFR had similar joint inflammation at baseline to those who did not, but had a better initial response to DMARD therapy. Further study of the potential impact of treatment based on ACPA status would be helpful.
Recent results from the ORAL Surveillance postmarketing safety analysis suggest that tofacitinib is associated with an increased risk for cancer in patients with RA patients who are aged >50 years, compared with anti–tumor necrosis factor (TNF) agents. Khosrow-Khavar and colleagues used insurance claims data to further investigate the risk for cancer with tofacitinib vs anti-TNF agents. They created two cohorts of patients who were new users of anti-TNF agents or tofacitinib: One was a "real-world" cohort including all patients with RA, whereas the other applied the inclusion and exclusion criteria from the ORAL Surveillance trial, including age >50 years, one cardiovascular risk factor, and use of methotrexate. Results from the real-world cohort, including over 10,000 patients who had used tofacitinib, did not show any increase in cancer risk, whereas the trial-simulating conditions did yield higher numbers of cancers in the group exposed to tofacitinib. Though reassuring, these results are limited by the short follow-up duration, and longer-term follow-up studies are necessary for further evaluation.
In another interesting note with respect to medication morbidity and risk, Xu and colleagues performed a meta-analysis looking at the association of methotrexate use and mortality in patients with RA. Only 15 studies were included in the final analysis, though they did encompass a large total number of patients. Overall, methotrexate use in these studies was associated with lower rates of overall mortality as well as mortality due to cardiovascular and interstitial lung disease. However, conclusions as to the direct impact of methotrexate were limited by the heterogeneity of study designs, doses of methotrexate, and additional therapy as well as comparators.