Researchers used a large database containing information about psoriasis patients, known as the PSOLAR registry, to search for any connection between biologics and serious infections. Biologics included in the study were Enbrel, Humira, Remicade and Stelara. The list of non-biologic treatments researchers analyzed included methotrexate, systemic retinoids and phototherapy.
Infections were considered serious if they were life-threatening or led to disability, hospitalization or some other medical condition, the researchers noted. The most common serious infections occurring in the study were pneumonia and cellulitis, a bacterial skin infection, according to the findings.
More than 11,000 psoriasis patients were included in the study. Of these, more than 9,000 were on biologics, 490 were on methotrexate and 1,610 were taking other treatments, according to the findings.
According to the results, the risk of developing a serious infection more than doubled for patients on Remicade or Humira, compared with patients not taking a biologic. Taking Stelara or Enbrel was not associated with risk for a serious infection, researchers found.
The results are in line with other studies that found a connection between a risk of serious infection and a type of biologic known as a tumor necrosis factor-alpha (TNF-alpha) inhibitor, the researchers noted. Both Humira and Remicade are TNF-alpha inhibitors. Enbel also targets TNF-alpha, but in a different way from Humira and Remicade, according to the researchers.
Stelara does not target TNF-alpha, but instead targets two different pro-inflammatory proteins, or cytokines, known as interleukin 12 and interleukin 23.
The study was funded by Janssen, the company that makes Stelara.