Study finds no new safety concerns with long-term sarilumab use for rheumatoid arthritis

Sarilumab, an IL-6 receptor inhibitor, has been approved for the treatment of subjects with moderate to severe rheumatoid arthritis (RA). Now, a recent study published in Rheumatology found that long-term therapy with sarilumab did not raise any new safety concerns, regardless of concomitant usage of standard synthetic DMARDs.

Dr. Burmester and co-researchers conducted the open-label extension evaluation to study the long-term safety of sarilumab in RA patients with or without conventional synthetic (cs) DMARDs. The study found that the rate of treatment-related adverse events per 100 patient years was 126 in the sarilumab monotherapy group, 169 in the sarilumab + csDMARD group, 159 in the continuation group, and 159 in the switch group. The most frequent adverse event was neutropenia, which returned to normal with continued treatment. The study also reported uncommon adverse events, including malignancies, serious adverse cardiovascular events, venous thromboembolism, and gastrointestinal perforations. However, the overall safety and efficacy of sarilumab with or without csDMARDs for RA patients were not found to be significantly different from previous studies, and improvements in clinical indications, symptoms, and health-related quality of life were sustained throughout the evaluation period.

A 2020 study also reported a stable and consistent long-term use of sarilumab with or without csDMARDs in RA patients. The study reported corresponding incidence rates per 100 patient-years for serious adverse events in the combination and monotherapy groups as 9.4 and 6.7 respectively. The incidence rates for serious infections were 3.7 and 1.0, for herpes zoster were 0.6 and 0.5, for gastrointestinal perforations were 0.1 and 0, and for malignancy were 0.7 and 0.6, respectively. The researchers also noted neutrophil counts<1000 cells/mm3 in 13% and 15% of patients respectively. However, there was no evidence of an increased risk of infection or serious infection associated with neutropenia. Moreover, the analysis did not reveal any increase in the rate of adverse events with time over a 6-month interval. Hence, sarilumab was found to have a stable and expected long-term safety profile, whether used alone or in combination with csDMARDs.

Both sarilumab monotherapy and combination treatment with csDMARDs have been shown to be safe and effective in the treatment of RA, but it is important to consider individual patient characteristics and preferences when selecting the most appropriate treatment approach.


  1. Burmester GR, Strand V, Kivitz AJ, Hu CC, Wang S, van Hoogstraten H, et al. Long-term safety and efficacy of sarilumab with or without background csDMARDs in rheumatoid arthritis. Rheumatology. 2023 Feb 2:kead062.
  2. Fleischmann R, Genovese MC, Lin Y, St John G, van der Heijde D, Wang S, Gomez-Reino JJ, et al. Long-term safety of sarilumab in rheumatoid arthritis: an integrated analysis with up to 7 years’ follow-up. Rheumatology. 2020 Feb 1;59(2):292-302.