Should tumour necrosis factor antagonist safety information be applied from patients with rheumatoid arthritis to psoriasis? Rates of serious adverse events in the prospective rheumatoid arthritis BIOBADASER and psoriasis BIOBADADERM cohorts

Background Information on the safety of tumour necrosis factor (TNF) antagonists frequently arises from their use in rheumatic diseases, their first approved indications, and is later applied to psoriasis. Whether the risk of biological therapy is similar in psoriasis and rheumatoid arthritis has been considered a priority research question. Objectives To compare the safety profile of anti-TNF drugs in patients with rheumatoid arthritis and psoriasis. Methods We compared two prospective safety cohorts of patients with rheumatoid arthritis and psoriasis that share methods (BIOBADASER and BIOBADADERM). Results There were 1248 serious or mortal adverse events in 16 230 person-years of follow-up in the rheumatoid arthritis cohort (3171 patients), and 124 in the 2760 person-years of follow-up of the psoriasis cohort (946 patients). Serious and mortal adverse events were less common in patients with psoriasis than in rheumatoid arthritis (incidence rate ratio of serious adverse events in psoriasis/rheumatoid arthritis: 0.6, 95% confidence interval 0.5-0.7). This risk remained after adjustment for sex, age, treatment, disease, hypertension, diabetes, hypercholesterolaemia and simultaneous therapy with methotrexate (hazard ratio 0.54, 95% confidence interval 0.47-0.61), and after excluding patients receiving corticosteroids. Patients with rheumatoid arthritis showed a higher rate of infections, cardiac disorders, respiratory disorders and infusion-related reactions, whereas patients with psoriasis had more skin and subcutaneous tissue disorders and hepatobiliary disorders. Conclusions Patients with rheumatoid arthritis clinical practice have almost double the risk of serious adverse events compared with patients with psoriasis, with a different pattern of adverse events. Safety data from rheumatoid arthritis should not be fully extrapolated to psoriasis. These differences are likely to apply to other immune-mediated inflammatory diseases.