Remicade & Humira Increase Cancer & Infection Risk

A Mayo Clinic study indicates that arthritis drugs Humira and Remicade triple the risk of many types of cancer and double the risk of serious infections . While the overall risk of developing cancer from these drugs remains small, the risk can vary widely by patient. The findings of this new study can be found in the May 17, 2006 issue of the Journal of the American Medical Association. It has been known for years that these treatments increase the risk of certain types of cancer or infection (such as lymphoma and tuberculosis). While even rarer than these previously-known (but uncommon) problems, there appears to be a slightly increased risk for a broader set of cancers and infections in patients undergoing anti-TNF treatment.

This is not the first time studies have indicated an increased risk of cancer and infection associated with these arthritis drugs. However, this study is the first to quantify these risks and discover additional types of cancer linked to Humira and Remicade. Previous evidence suggested that these drugs might increase the risk of lymphoma , a cancer of the lymph nodes. Past research also found that the risk of tuberculosis and pneumonia was greater for patients taking Humira or Remicade.

The study, led by investigators at Mayo Clinic, used "meta-analysis" to combine and assess the results from a large set of clinical studies already in the literature. With the large number of patients and years of treatment represented by these combined studies, less common events associated with treatment can be detected. Overall, the study suggests that the increased risk of cancer (lymphoma, skin, gastrointestinal, breast and lung) or serious infection may be three-fold and two-fold, respectively. These serious side effect risks appear to be greatest when higher doses are used. The risk appears to be mainly in patients receiving high dose treatment (more than 6 mg/kg every 8 weeks; or adalimumab, 40 mg every other week). Researchers also noted that older sicker patients who have taken this medication for an extended time are at the greatest risk for these arthritis drug side effects.

While medical researchers at the Mayo Clinic noted the benefits of Humira and Remicade-including increased range of motion, flexibility, and life expectancy and a reduction in pain-they caution patients and medical providers to be aware of these risks and their symptoms.
Patients taking these medications should seek medical attention at the first sign of infection , such as a fever, cough, or related symptoms. Some patients may wish to consider cancer screenings; those which are recommended to the general public.

Abbott Laboratories and Centocor, the makers of Humira and Remicade, respectively, have criticized the Mayo Clinic's study, claiming that this new evidence does not prove that these arthritis drugs cause cancer and infection. Other experts have raised questions as to whether the increased risk of cancer is actually attributable to the drugs or the disease itself. The exact reason for these increased risks remains unclear.

An additional drug, Enbrel , was not included in this study, as it differs at the molecular level. Researchers say a study on this arthritis drug is in the works.