Enbrel has been linked to sometimes deadly infections when administered to children, casting doubts that the Food & Drug Administration (FDA) will approve the Amgen and Wyeth drug to treat severe psoriasis in children. Enbrel is already approved to treat psoriasis and rheumatoid arthritis in adults and juvenile arthritis in children.
Enbrel is made from a type of protein called a tumor necrosis factor (TNF) blocker that blocks the action of a substance made by the body’s immune system called TNF. People with an immune disease, such as rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis, and psoriasis, have too much TNF in their bodies. The FDA first approved Enbrel in 2000 for treating rheumatoid arthritis, and its approved uses where expanded several times to include psoriasis and other conditions.
In April, the FDA had Amgen and Wyeth include a new black box warning on the Enbrel label stating that the drug has been associated with serious infections, including tuberculosis in some patients. The new Enbrel black box warning was prompted by global studies of over 20,000 patients taking Enbrel, where tuberculosis was observed in about 200 people.
Today, FDA scientists expressed concern about broadening the drug’s approval, citing reports of dangerous side effects in children who have already taken the drug. Reports submitted to the agency linked to infections that sometimes led to hospitalization and death. Of the 14 deaths recorded by the FDA, more than half were in children taking Enbrel for arthritis, while the others were among children taking the drug for unapproved uses. The FDA scientists also recommended that stronger warnings about the possibly-fatal infections be added to Enbrel’s label.
On Wednesday, an FDA advisory panel will vote on whether Enbrel should be cleared for the new use. The FDA is not required to follow the panel’s advice, though it usually does.
The FDA is also reviewing Enbrel and other TNF blockers over a possible link to cancer. 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.