FDA forces manufacturers of TNF-blockers to highlight risk of fungal infections

The U.S. Food and Drug Administration today announced that the manufacturers of Humira, Cimzia, Enbrel, and Remicade must strengthen the existing warnings, in the Warnings and Precaution sections of the drugs' prescribing information and Medication Guides, on the risk of developing opportunistic fungal infections. Some patients with invasive fungal infections have died.

The four drugs, known as tumor necrosis factor alpha blockers (TNF-alpha blockers), which suppress the immune system, are approved to treat a variety of conditions which may include rheumatoid arthritis, juvenile idiopathic arthritis, psoriatic arthritis, plaque psoriasis, ankylosing spondylitis, and Crohn's disease.

FDA today exercised its new authority under the Food and Drug Administration Amendments Act of 2007 to require manufacturers of TNF inhibitors to make safety-related changes to prescribing information, or labeling.

"Under the FDA's new authorities, we can require safety label changes and a risk evaluation and mitigation strategy, known as REMS, when the agency becomes aware of new safety information," said Bob Rappaport, M.D., director of the Division of Anesthesia, Analgesia and Rheumatology Products, Center for Drug Evaluation and Research. "Requiring the risks to be highlighted will help health care professionals be more vigilant in watching for these adverse events, and is necessary to ensure that the benefits of these drugs outweigh their risks."

Since the initial approval of the four TNF blockers, the prescribing information for these drugs has included information about the risk of serious infections, including fungal infections. However, based on reports reviewed by FDA, health care professionals are not consistently recognizing cases of histoplasmosis and other invasive fungal infections, leading to delays in treatment.

Patients taking TNF blockers should be aware that they are more susceptible to serious fungal infections. Those who develop a persistent fever, cough, shortness of breath, and fatigue should promptly seek medical attention. To assist in the diagnosis, those being treated with TNF blockers should tell their health care professionals where they live and what areas they have recently visited. Patients who develop a fungal infection may be advised to stop the TNF blocker until they recover.

FDA has reviewed 240 reports of histoplasmosis, an infection caused by the fungusHistoplasma capsulatum, in patients being treated with Enbrel, Humira, or Remicade. The majority of the reports involved people in the Ohio River and Mississippi River valleys (the fungus is commonly found in those areas). In at least 21 of the reports, histoplasmosis was initially not recognized by health care professionals, and antifungal treatment was delayed. Twelve of those patients died.

The FDA reviewed one reported case of histoplasmosis in a patient taking Cimzia. The FDA also has received reports of cases of coccidioidomycosis and blastomycosis, including deaths, in patients treated with TNF blockers.

TNF blocker manufacturers are required to submit safety labeling changes, including strengthened warnings and revisions to the Medication Guides to the FDA within 30 days or to provide a reason why they do not believe labeling changes are necessary.

If they do not submit new language, or if the FDA disagrees with the new language the company proposes, the Food and Drug Administration Amendments Act of 2007 provides strict timelines for resolving the labeling changes and allows the agency to issue an order directing the labeling change as deemed appropriate to address the new safety information.

Medication Guides will become part of a REMS for Humira and Remicade and are already part of a REMS for Enbrel and Cimzia. The manufacturers for all four of these drugs will also be required to educate prescribers about the risks.

For more information: http://www.fda.gov/cder/drug/InfoSheets/HCP/TNF_blockersHCP.htm