Drugs used to treat rheumatoid arthritis, psoriasis, Crohn's disease and other conditions have been found to lead to an increased risk of cancer and serious infection such as pneumonia, according to a US study released on May 17.
The Mayo Clinic study analysed nine previous studies of tumour necrosis factor (TNF) blocking antibodies which have been prescribed to more than half a million patients.
The researchers found that those treated with TNF-blocking antibodies had 3.3 times the risk of developing cancer than those given placebo, and 2.2 times the risk of serious infection, the Rochester, Minnesota-based Mayo Clinic said in a press release.
Cancers were much more common in those patients treated with high doses of TNF-blocking antibodies.
The antibodies might be connected with an increased risk for infection and malignancies because the drugs interfere with immunological mechanisms critical to fighting infection and the body's normal function in surveying itself for cancerous cells, researchers said.