Although drugs that act to suppress part of the immune system are invaluable in the treatment of certain autoimmune disorders, there can be higher risks of cancers and infections associated with their use. Now the US Food and Drug Administration (FDA) is investigating a possible connection between a highly successful group of these drugs and cases of cancer in under 18s.

Tumour necrosis factor blockers, including the best-selling drugs Remicade, Enbrel and Humira, have been successful in treating diseases such as rheumatoid arthritis, psoriasis and Crohn disease, along with juvenile idiopathic arthritis (JIA) in children and young adults. However, in the last 10 years approximately 30 cancer cases, of which half were lymphomas, have been reported in young patients receiving the drugs.

Health professionals have welcomed the investigation, as Dr Chaim Putterman, of Montefiore Medical Center and Albert Einstein College of Medicine, explains: “this is an area of ongoing concern that has not been resolved” (http://www.washingtonpost.com/ 4 Jun 2008). Dr. Edward H. Giannini, professor of paediatric rheumatology at the University of Cincinnati, agrees, “We have to be careful with the safety aspects of giving immune response modifiers to very young children,” but emphasizes the benefits of the drugs: “[JIA] was a disease that put kids in wheelchairs” (http://www.nytimes.com/ 5 Jun 2008).

The FDA highlights the need for long-term studies to ascertain whether use of these products increases cancer incidence, owing to the time cancers take to develop. In the meantime it advises that the “potential benefits ... outweigh the potential risks in certain children and young adults having one of the diseases for which the TNF blockers are approved” (http://www.fda.gov/ 4 Jun 2008).