FDA: Arthritis Drugs Up Kid's Cancer Risks

Federal regulators on Tuesday added stronger warnings to a group of best-selling drugs used to treat arthritis and other inflammatory diseases, saying they can increase the risk of cancer in children and adolescents.

After more than a year of review, Food and Drug Administration scientists said the drugs appear to increase the risk of cancer after they are used beyond 2 1/2 years. The agency studied several dozen reports of cancer in children taking the drugs, some of which were fatal. Half of the cases were lymphomas, a cancer that attacks the immune system.

The drugs are known as tumor necrosis factor blockers and work by neutralizing a protein that, when overproduced, causes inflammation and damage to bones, cartilage and other tissue. The drugs are prescribed to children with rheumatoid arthritis, inflammatory bowel disorder and Crohn's disease.

The FDA will bolster the "black box" warning on the five drugs sold in the U.S., including Abbott Laboratories' Humira, Johnson & Johnson's Remicade and Simponi, and Enbrel which is co-marketed by Amgen Inc. and Wyeth. All the products are multibillion-dollar sellers. Enbrel was the biggest moneymaker of the group with sales of $3.4 billion last year.

The action also affects Belgian drugmaker UCB's Cimzia, which launched in May.

Shares of North Chicago-based Abbott Laboratories and New Brunswick, N.J.-based J&J fell after the FDA announcement.

Along with updating the drugs' labels, the FDA is requiring companies to add information about cancer risks to the medication guides given to patients. The FDA said it is also working with the manufacturers to further define the scope of the cancer risk.

J&J said in a statement it "will coordinate closely with the FDA to ensure that health care providers, patients and caregivers are properly informed."

Amgen and Wyeth said they will continue working with regulators to evaluate "the potential risks and benefits" of their drug.