Differences Identified in Serious Infection Risk Among Biologic Drugs for Rheumatoid Arthritis

Although antitumor necrosis factor therapy has been associated with an increased risk for infection compared with conventional synthetic disease-modifying antirheumatic drugs in patients with RA, the infection risk with other biologics has not been confirmed.^2-4 Therefore, using data from the British Society for Rheumatology Biologics Register for Rheumatoid Arthritis, researchers compared the incidence of SI.

SI was defined as an infectious event requiring admission to a hospital, needing intravenous antibiotics, or resulting in death across biologic drugs used to treat RA.¹ The overall incidence of SI was found to be 5.51 events/100 patient years for a cohort of 19,282 patients with 46,771 years of follow-up. Etanercept was the largest cohort and was used as the reference for all other comparisons.

The only drugs that had significantly different rates of SI compared with etanercept were rituximab, tocilizumab, and certolizumab pegol. Tocilizumab and rituximab both had higher rates of infection (6.98 cases and 6.29 cases/100 patient years), whereas certolizumab pegol had the lowest crude incidence of infection (3.80 cases/100 patient years).

Respiratory infections accounted for 42% of all SI and were the most frequently reported, followed by soft tissue and skin infections. The overall 30-day mortality rate after a SI was 10.4%. Although sepsis was found to be a significant predictor of mortality, choice of biologic treatment was not.

“For the majority of patients, biologic therapies remain a safe and efficacious treatment strategy. However, in a population of ‘high-risk’ individuals, differences in the relative risk of infection can have a significant impact on the absolute risk of SI,” concluded the authors.¹

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References

1. Rutherford AI, Subesinghe S, Hyrich KL, et al. Serious infection across biologic-treated patients with rheumatoid arthritis: results from the British Society for Rheumatology Biologics Register for Rheumatoid Arthritis [published online March 28, 2018]. Ann Rheum Dis. doi: 10.1136/annrheumdis-2017-212825
2. Curtis JR, Patkar N, Xie A, et al. Risk of serious bacterial infections among rheumatoid arthritis patients exposed to tumor necrosis factor alpha antagonists. Arthritis Rheum. 2007;56:1125-1133.
3. Galloway JB, Hyrich KL, Mercer LK, et al. Anti-TNF therapy is associated with an increased risk of serious infections in patients with rheumatoid arthritis especially in the first 6 months of treatment: updated results from the British Society for Rheumatology Biologics Register with special emphasis on risks in the elderly. Rheumatology 2011;50:124-131.
4. Askling J, Fored CM, Brandt L, et al. Time-dependent increase in risk of hospitalization with infection among Swedish RA patients treated with TNF antagonists. Ann Rheum Dis. 2007;66:1339-1344.