The tumor necrosis factor inhibitors Enbrel (etanercept), Humira (adalimumab), Remicade (infliximab) and Cimzia (certolizumab pegol) are being investigated by the US Food and Drug Administration (FDA) after being linked to about 30 cases of cancer. The cancers (mostly lymphomas, though leukemia, melanoma and solid organ cancers also surfaced) occurred between 1998, the year Remicade was approved, and the end of April this year, and were found in children or young adults who began using the drugs before the age of 18 to fight Crohn's, juvenile idiopathic arthritis or other diseases. Though the patients also were taking other immunosuppressive drugs, and cancers can normally occur in children, FDA said the tumor necrosis factor (TNF) inhibitors-cancer connection is “of concern” and deserves “further investigation.” Toward that end, FDA asked Enbrel manufacturers Amgen, of Thousand Oaks, California, and Wyeth, of Madison, New Jersey; Humira manufacturer Abbott Laboratories of Abbott Park, Illinois; and Remicade manufacturer Eli Lilly of Indianapolis to provide information on all reported cancers in children taking the inhibitors. UCB, of Brussels, maker of Cimzia, is required to conduct a 10-year study beginning next year, as the product is approved for only Crohn's disease and not yet cleared for use in children. Still, FDA, the companies and the Arthritis Foundation all suggest the benefits of the products outweigh the risks, and so far, sales have not slipped. “The whole [TNF inhibitor] market has been growing really robustly,” says Mark Schoenebaum, an analyst in New York with Deutsche Bank. “People thought this market was mature years ago, but it's been growing...year on year.”