Arthritis Drugs to Have Stricter Warning of Fungal Infection Risk

By Anastacia Mott Austin

Doctors prescribing the popular arthritis drugs Enbrel, Remicade, Humira, and Cimzia already knew of their risk for fungal infections.

Because these drugs belong to a class called TNF blockers, they suppress the immune system. Arthritic conditions are frequently caused by an overreaction of the immune system, causing joint inflammation, so TNF blockers will help control joint pain.

But because of the immune system suppression, patients using these drugs are more susceptible to some types of disease, in this case fungal infections.

And while doctors and patients have been aware of these risks, one particular type of fungal infection is proving to be deadly.

The FDA received 240 reports of histoplasmosis in patients taking one of these arthritis drugs. Forty-five of these patients died, a 20% rate of death.

Alarmed that doctors were possibly missing the signs of histoplasmosis and delaying crucial treatment, the FDA is requiring the drugs to carry a special warning about histoplasmosis. The drugs listed above all currently carry black-box warnings about fungal infections, but not histoplasmosis in particular.

Histoplasmosis can start as a respiratory infection, and because symptoms mimic the flu, sometimes patients don’t get proper treatment to stop the infection before it spreads throughout the rest of the body.

Patients in the Midwest are even more susceptible to this particular fungal infection, as it is more common in the area.

"We're going to make sure that all the boxed warnings state clearly that fungal infections – including in particular histoplasmosis, which is the main one that has come to our attention as having been missed in a number of cases – will be highlighted," said Dr. Jeffrey Siegel, the team leader in the rheumatology department of the FDA’s Center for Drug Evaluation and Research.

All of the drug makers in question have said they will comply with the FDA regulations to add specific warnings about histoplasmosis. Bert Kelly, a representative for UCB, which manufactures Cimzia, told reporters, "We had very strong safety language, [but] if the FDA thinks there needs to be some stronger language, we'll work to get that done."

The TNF blocker drugs are used in a variety of arthritic conditions, including rheumatoid arthritis, Crohn’s disease, and juvenile idiopathic arthritis.