WASHINGTON U.S. health officials are investigating whether drugs for rheumatoid arthritis and Crohn's disease are linked to cancers in children and young adults, the Food and Drug Administration said on Wednesday.
The prescription drugs, members of a family called TNF blockers, include Johnson & Johnson's Remicade, Abbott Laboratories Inc's Humira, and Amgen Inc and Wyeth's Enbrel.
The FDA said it was probing about 30 reports of cancer in children and young adults treated with TNF blockers plus other immune-suppressing medicines between 1998 and April 29, 2008. About half of the cancers were lymphomas.
A fourth TNF blocker, UCB's Cimzia, won FDA approval on April 22, 2008.
The prescribing information for all four drugs already warns about a possible risk of cancer.
Still, "the reports of these events in children and young adults receiving TNF blockers are of concern and deserve further investigation," an FDA statement said.
The agency said it currently believed potential benefits outweighed the risks for certain young people with diseases the drugs are approved to treat.
The drugs are big sellers. Johnson & Johnson reported $998 million in revenue from Remicade in the first quarter. J&J reported $16.2 billion in total revenue for the quarter. Likewise, Humira sales hit $878 million in the quarter; Abbott's total revenue for the quarter was $6.76 billion.
Enbrel sales generated $951 million, according to the companies. Amgen had total revenue of $3.6 billion for the quarter and Wyeth had revenues of $5.7 billion.
The FDA said it asked the makers of Remicade, Enbrel and Humira for information on all cases of cancer reported in children and young adults treated with the drugs. UCB is planning a study of long-term risks of Cimzia, including cancer. That study is expected to start next year and take about 10 years to finish, the FDA said.
Amgen estimates that fewer than half of the 30 cases cited by the FDA were reported in Enbrel patients, company spokeswoman Sonia Fiorenza said. Enbrel was the first of the drugs approved, winning clearance in 1998.
Amgen and Wyeth support the FDA review and will provide any requested information, Fiorenza said.
For Remicade, the vast majority of patients who developed cancer were being treated for the bowel disorder Crohn's disease, and all but one also were given other immune-suppressing drugs that are suspected to carry a cancer risk, said Brian Kenney, a spokesman for J&J's Centocor unit.
Kenney said he could not provide the specific number of cancer cases reported for Remicade. Schering-Plough Corp sells Remicade outside the United States.
Abbott has not seen any cases of lymphoma or other cancers in children given Humira in clinical trials, company spokeswoman Raquel Powers said. The company is working with the FDA to evaluate all available data, she added.
UCB's Cimzia is not approved for children. The company will closely monitor for any health problems in Cimzia patients, UCB spokesman Bert Kelly said.
The injectable drugs suppress the immune system by blocking the activity of TNF, a chemical that can cause inflammation.
Each is approved to treat one or more immune system diseases including rheumatoid arthritis, plaque psoriasis and Crohn's disease.
Cancers were reported in patients treated with the drugs for juvenile idiopathic arthritis, which the FDA said was a new name for juvenile rheumatoid arthritis, as well as Crohn's and other conditions.
The FDA said it would announce findings of its review and any recommendations within about six months.
Long-term studies are needed, however, to provide definitive answers as cancers take a long time to develop, the FDA said.
(Additional reporting by Philip Blenkinsop in Brussels, editing by John Wallace, Leslie Gevirtz)