November 17, 2011

Autoimmune drugs don’t boost infection risk: study

Autoimmune drugs don’t boost infection risk: study

Effective injectable biologic drugs used to treat autoimmune disorders such as rheumatoid arthritis (RA), inflammatory bowel disease (IBD) and psoriasis do not increase the risk of hospitalization for serious infection compared with the use of other non-biologic medications, according to a Vanderbilt study published in the Journal of the American Medical Association (JAMA).

A class of drugs, known as tumor necrosis factor (TNF)-α antagonists, has revolutionized the treatment of autoimmune disorders, which occur when the body’s immune system attacks healthy cells and tissue. They are known as biologic medications because their substances occur naturally in animals and humans. They work by blocking the TNF-a molecule.

Carlos Grijalva, M.D., MPH

Carlos Grijalva, M.D., MPH

But concerns about their safety have remained because they suppress the immune system. Previous studies have reported serious infections in users of TNF-a antagonists compared with placebo, but whether that risk is greater than with non-biologic medications had previously been unclear.

Carlos Grijalva, M.D., MPH, assistant professor of Preventive Medicine, and colleagues compared the risk of serious infections for both types of medications by combining data from four major U.S. databases (1998-2007) and comparing the occurrence of hospitalizations for infections among patients initiating TNF-a antagonists or non-biologic regimens.

Data analyses indicated that hospitalization rates for serious infection were not significantly different between the TNF-a antagonists overall and the comparator non-biologic regimens for RA, IBD, and psoriasis, psoriatic arthritis or ankylosing spondylitis.

“I think it should be reassuring for patients and providers that in this large study we observed that these biologic medications did not increase the risk of serious infections when compared with other non-biologic treatments,” Grijalva said.

“Patients and providers can evaluate this and other available information to make informed decisions about the best options for their treatment.”

Study authors did report that, among patients with RA, the medication infliximab was associated with a significant increase in serious infections compared with the drugs etanercept, adalimumab and other non-biologic medications.

A multi-institution collaboration, called the Safety Assessment of Biologic Therapies, or SABER, was established for the study and included Vanderbilt University, the University of Alabama at Birmingham, Harvard University, Kaiser Permanente Northern California, Oregon Health and Sciences University, University of Pennsylvania, the Food and Drug Administration (FDA) and the Agency for Healthcare Research and Quality (AHRQ).

The study was funded by the FDA, AHRQ, Department of Health and Human Services and the National Institutes of Health.