The US Food and Drug Administration is requiring stronger warnings in the prescribing information for a class of drugs known as TNF blockers. The warnings, which include an updated boxed warning, highlight the increased risk of cancer in children and adolescents who receive these drugs to treat juvenile rheumatoid arthritis, the inflammatory bowel disorder, Crohn's disease, and other inflammatory diseases.

In addition, the FDA is working with manufacturers to explore new ways to further define the risk of cancer in children and adolescents who use these drugs.

TNF blockers target and neutralize tumour necrosis factor-alpha (TNF-a), a protein that, when overproduced in the body due to chronic inflammatory diseases, can cause inflammation and damage to bones, cartilage and tissue. The drugs in this class include Remicade (infliximab), Enbrel (etancercept), Humira (adalimumab), Cimzia (certolizumab pegol) and Simponi (golimumab).

This action is based on the completion of an investigation first announced by the FDA in June 2008. An analysis of US reports of cancer in children and adolescents treated with TNF-blockers showed an increased risk of cancer, occurring after 30 months of treatment on average. About half of the cancers were lymphomas, a type of cancer involving cells of the immune system. Some of the reported cancers were fatal.

Additional required updates to the prescribing information include incorporation of reports of psoriasis associated with the use of TNF blockers.