Serious adverse events in trials evaluating biologics in psoriasis

Psoriasis is a common skin disease that causes itchy scaly patches, most frequently on the knees, elbows and scalp. It affects about 2–3% of people in the world. Patients with moderate‐to‐severe cases are often treated with drugs called biologics. Research that has combined the results of a number of trials (meta‐analysis) of patients taking biologics who had moderate‐to‐severe psoriasis found an absence of increased risk of serious adverse events (SAEs) with these treatments compared with placebo (which looks like the drug being tested but does not contain any medicine). Yet, biologics are known to increase the risk of serious infections, because of the suppressant effect on these drugs on the immune system. SAEs are unwanted side‐effects during the trial that may be life‐threatening or result in (prolonged) hospitalization. All such events are counted including cases of disease worsening. Worsening is a treatment failure and thus logically occurs more frequently in the placebo group. Including cases of psoriasis worsening may explain the lack of difference. Our study aimed to explore the reasons for the absence of difference in SAEs between biologics and placebo. First, the number of SAEs observed (as reported in all trials) in patients in the treatment group was compared with that in the placebo group. Second, the same analysis was performed, but excluding cases of psoriasis worsening. Our analyses showed that the exclusion of cases of psoriasis worsening revealed an increased risk of SAEs in the treated group compared with the placebo group. We therefore recommend the results for SAEs overall and SAEs excluding disease worsening should be presented in the results of trials and meta‐analysis. Linked Article:   Afach et al. Br J Dermatol 2021; 184 :415–424.