The agency is conducting a safety review of Enbrel, Humira, Cimzia and Remicade for a possible association with lymphoma and other cancers in children and young adults who have Juvenile Idiopathic Arthritis and Crohn’s disease. So far, the FDA has received 30 reports over the past 10 years, and about half of the cancers were lymphomas and included both Hodgkin’s and non-Hodgkin’s lymphoma.

The FDA notes that the drugs suppress the immune system by blocking the activity of TNF, a substance in the body that can cause inflammation and lead to immune system-related diseases such as JIA, and Crohn’s disease. And the agency has been aware of the possible association between the use of TNF blockers and the development of cancer - prescribing info for all four TNF blockers warns about the possible risk of cancer. This is the FDA statement.

Meanwhile, the FDA is requiring Nektar Therapeutics, which makes Cimzia to conduct a study to assess long-term risks, including lymphoma and other cancers, to begin in 2009. It will take about 10 years to complete. Amgen makes Enbrel, while Humira is sold by Abbott Labs and Johnson & Johnson markets Remicade. The FDA asked these drugmakers to provide info about all cases of cancer reported in children taking TNF blockers.

Here is a statement from Amgen and Wyeth, which jointly market Enbrel.