The U.S. Food and Drug Administration has approved the use of Humira (adalimumab) to treat adults suffering moderately to severely active Crohn's disease.

The FDA described Crohn's disease as a chronic, incurable, inflammatory bowel disease that causes diarrhea, cramping and abdominal pain and in some cases, abnormal connections (fistulas) leading from the intestine to the skin. It affects an estimated 1 million Americans.

Humira is a human-derived, genetically engineered monoclonal antibody that acts to reduce excessive levels of human tumor necrosis factor alpha, which plays an important role in abnormal inflammatory and immune responses.

The FDA's action Tuesday followed four clinical trials involving 1,478 patients.

The labeling of Humira includes a boxed warning, the strongest type of FDA label warning, that use of the product has been associated with serious, sometimes fatal, infections, including cases of tuberculosis, opportunistic infections, and sepsis.

The FDA said patients should be evaluated for TB risk factors and tested for latent tuberculosis infection before starting Humira treatment.

Humira, manufactured by Abbott Laboratories, was previously approved for the treatment of rheumatoid arthritis, psoriatic arthritis, and ankylosing spondylitis, a systemic rheumatic disease that affects the spine and sacroiliac joints. [UPI Science News - Feb. 28, 2007]