Boxed Warning for Infections and TB Added to Etanercept (Enbrel)

By Todd Neale
ROCKVILLE, Md., 05 may 2008-- A boxed warning has been added to the label for etanercept (Enbrel), the tumor necrosis factor-alpha inhibitor for rheumatoid arthritis, to strengthen awareness of the risk of infections, particularly tuberculosis, the FDA announced today.
The warning, which points out that serious infections leading to hospitalization or death can occur with the use of the agent, has been changed to recommend screening for latent tuberculosis infection (LTBI) before treatment.
It also says that patients who develop an infection should be monitored for possible antimicrobial treatment and that etanercept should be stopped if a serious infection develops.
"Tuberculosis (frequently disseminated or extrapulmonary at clinical presentation) has been observed in patients receiving TNF-blocking agents, including Enbrel," the warning points out. "Tuberculosis may be due to reactivation of latent tuberculosis infection or to new infection. Data from clinical trials and preclinical studies suggest that the risk of reactivation of latent tuberculosis infection is lower with Enbrel than with TNF-blocking monoclonal antibodies. Nonetheless, postmarketing cases of tuberculosis reactivation have been reported for TNF blockers, including Enbel."
The section on adverse events now reads, "In global clinical studies of 20,070 patients (28,308 patient-years of therapy), tuberculosis was observed in approximately 0.01% of patients. In 15,438 patients (23,524 patient-years of therapy) from clinical studies in the U.S. and Canada, tuberculosis was observed in approximately 0.007% of patients. These studies include reports of pulmonary and extra-pulmonary tuberculosis."
The changes were distributed to clinicians in a letter from Amgen and Wyeth, which market the drug for the manufacturer, Immunex.
Etanercept is approved for moderate-to-severe rheumatoid arthritis, moderate-to-severe polyarticular juvenile idiopathic arthritis, psoriatic arthritis, ankylosing spondylitis, and moderate to severe plaque psoriasis