J&J warns Remicade may cause blood disorders

Johnson & Johnson has added a new warning to the label for rheumatoid arthritis drug Remicade about blood disorders that sometimes were fatal, US regulators have announced.

Johnson & Johnson, said in a letter to doctors that the "causal relationship" between Remicade and the disorders "remains unclear." The reported problems included a dangerous reduction in the number of white blood cells that can leave patients vulnerable to infections.

The company also added warning language about rare cases of blood vessel inflammation in the brain and spinal cord experienced by patients treated with Remicade.

Worldwide, 508 cases of both types of problems have been reported, said Craig Buchholz, a spokesman for Johnson & Johnson unit Centocor. He said he did not know how many were fatal.

About 509,000 patients have been treated with Remicade, Buchholz said.

The company's letter, which was posted on the Food and Drug Administration's Web site, advised caution when prescribing Remicade to patients with a history of significant blood abnormalities. Patients should be told to immediately seek medical attention if they develop a persistent fever or other signs suggestive of an infection.

Rival arthritis drugs, Amgen’s Enbrel and Abbott Laboratories’ Humira, carry similar warnings about blood disorders on their labels.

All three prescription drugs work by blocking an inflammation-causing protein called tumour necrosis factor. The drugs also carry warnings that they may raise the risk of contracting tuberculosis.

Despite those rare problems, the medicines are enjoying strong revenue growth because of their ability to control symptoms of rheumatoid arthritis -- the less common and hereditary form of arthritis in which the immune system attacks joints.

Remicade also is approved for treating the bowel disorder.