Amgen and Wyeth Pharmaceuticals, a division of Wyeth, announced updates to the US Food and Drug Administration (FDA)-approved US Prescribing Information (PI) for Enbrel (etanercept).
The US PI now contains a boxed warning relating to the risk of infections, including tuberculosis, which is similar to labelling for other medicines in the tumour necrosis factor (TNF) inhibitor class. The PI had previously included a bolded warning regarding the risk of infections and tuberculosis. This information is now in a boxed warning and includes additional language regarding screening and monitoring patients for tuberculosis, including patients who tested negative for latent tuberculosis infection.
In addition, the boxed warning states that tuberculosis has been observed in patients receiving TNF-blocking agents, including Enbrel, and that tuberculosis may be due to reactivation of latent tuberculosis infection or to new infection. The boxed warning notes that 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. The boxed warning further notes that, nonetheless, post-marketing cases of tuberculosis reactivation have been reported for TNF blockers, including Enbrel.
The risks defined in the boxed warning are consistent with the risk of tuberculosis and infections that have been included in previous versions of the US PI. The primary concern of both Amgen and Wyeth is for the safety of patients, and both companies maintain an ongoing pharmacovigilance program to analyze and evaluate all safety reports from clinical and open-label trials as well as post-marketing surveillance. As always, it is important that physicians and patients fully understand the benefits and risks of Enbrel treatment, the company said.
Other PI updates include the addition of reported incidence of tuberculosis infection observed in clinical studies in the Adverse Reactions section. In global clinical studies of more than 20,000 patients, tuberculosis was observed in approximately 0.01 percent of patients. In more than 15,000 patients from clinical studies in the US and Canada, tuberculosis was observed in approximately 0.007 percent of patients. The Adverse Reaction Information from Spontaneous Reports section was also updated based on post-marketing surveillance reports. Additional information was added regarding antibody assays in the immunogenicity section.
The indication within the US PI for juvenile idiopathic arthritis (JIA) - formerly called juvenile rheumatoid arthritis (JRA) - also was changed. Enbrel now has an updated JIA indication for reducing the signs and symptoms of moderately to severely active polyarticular juvenile idiopathic arthritis in patients ages 2 and older.
In addition to these US PI updates, the current patient package insert (PPI) for Enbrel will be replaced with a Medication Guide when it becomes available. Patients will receive the Medication Guide when a prescription for Enbrel is dispensed in the US. As with the current PPI, Amgen and Wyeth will distribute the Medication Guide in conjunction with any company-sponsored patient communications about Enbrel.
Enbrel is a fully human soluble tumour necrosis factor (TNF) receptor. Enbrel was first approved in 1998 for moderate to severe rheumatoid arthritis and has more than 15 years of collective clinical experience.
Enbrel is indicated for reducing signs and symptoms, keeping joint damage from getting worse, and improving physical function in patients with moderate to severe rheumatoid arthritis. It is also indicated for reducing the signs and symptoms of moderately to severely active polyarticular juvenile idiopathic arthritis in patients ages 2 and older.