Non-Serious Infection Risk with Biologics in RA Save

Nonserious infections (NSI) comprise the bulk of all infections seen with biologic therapies; new data from British Society for Rheumatology Biologics Register for Rheumatoid Arthritis (BSRBR-RA) shows that while NSI are more common than serious infections (SIE), the predictors of NSI are the same as serious infections (SIE). 

The BSRBR-RA prospectively and serially assesses patients starting biologic therapies for RA. For this study an NSI was defined as any infection not requiring hospitalization or intravenous therapy.  Biologics included rituximab, tocilizumab, etanercept, adalimumab, infliximab, and certolizumab. KAK inhibitors (tofacitinib and baricitinib) and sarilumab cohorts were recruited laters (2017/2018) and not included. Abatacept and golimumab cohorts were not recruited.

Among 8145 RA patients there were 17,304 NSI recorded.  The most common NSI were respiratory (6,268), urinary (2,921), ENT (2,486), skin (1,850) or 0ral (791).

An increased risk of NSI was associated with:

• Increasing age
• Female sex
• Comorbidity burden
• Glucocorticoid therapy
• Higher DAS28 Scores
• Higher Health Assessment Questionnaire disability index

The risk of NSI was significantly lower with csDMARDs compared to biologic treatments.

Compared to TNFi, IL-6 inhibition and rituximab were associated with a higher NSI risk (adjusted hazard ratio 1.45 [95% CI 1.29–1.63] and adjusted hazard ratio 1.28 [95% CI 1.14–1.45], respectively). By comparison, csDMARDs had a lower risk (adjusted hazard ratio 0.64 [95% CI 0.59–0.70]).

Among the TNF inhibitors, adalimumab was associated with a higher NSI risk than etanercept (adjusted hazard ratio 1.11 [95% CI 1.05–1.17]).

While NSI are more common than serious infections (SIE), the predictors of NSI and SIE are similar.