Humira, Enbrel, Remicade Being Investigated. Humira and other drugs used to treat autoimmune disorders are being investigated by federal regulators amid concern that they might be linked to cancer in children and young people. The drugs are known as tumor necrosis factor (TNF) blockers, and are used to treat various forms of arthritis including juvenile idiopathic arthritis and Crohn’s disease.
In addition to Humira, which is made by Abbott Laboratories, four other TNF blockers are currently on the market in the US. They are Enbrel, marketed by Wyeth and Amgen; Remicade sold by Schering-Plough; and Cimizia, made by UCB of Belgium. TNF blockers impede the action of a substance made by the body’s immune system called TNF. People with an autoimmune disease, such as rheumatoid arthritis, have too much TNF in their bodies.
Enbrel and Humira are approved to treat children with juvenile rheumatoid arthritis, according to the FDA. The FDA is requiring the maker of Cimzia to conduct a study to assess long-term risks of the product, including lymphoma and other cancers. This study will begin in 2009 and take about 10 years to complete. All of the labels for the drugs currently address the possible risk of cancer when taking the drug.
The FDA is investigating about 30 reports of leukemia
The FDA is investigating about 30 reports of leukemia, lymphoma and other cancers in children and young adults submitted between 1998, after the approval of the first TNF blocker, through April of this year. Approximately half of the reports were lymphomas, cancer of the immune system cells, that were both Hodgkin’s and non-Hodgkin’s based.
The FDA has requested that makers of TNF blockers approved for use in children and young adults supply information about all reported cases of cancer among patients in these age groups taking the drugs. The FDA has also asked health-care professionals to weigh the possible risks against the benefits when prescribing TNF blockers.
In addition to the possible cancer risk, TNF blockers have been associated with an increased risk of some infections. In May, Enbrel had its label modified to include a black box warning – the FDA’s strictest safety alert – about its association with serious infections, including tuberculosis. The warning was prompted by global studies of over 20,000 patients taking Enbrel, where tuberculosis was observed in about 200 people.