Researchers now say that two biotech drugs used to treat rheumatoid arthritis, Humira (Abbott Laboratories) and Remicade (Johnson & Johnson), may not raise the risk of cancer and infections as much as was initially feared.
A series of published letters from several teams of researchers show that after a fresh look at the safety of the two drugs, they may double the risk of cancer and infections rather than tripling such risks, as was first stated.
The majority of the researchers along with the U.S. Food and Drug Administration (FDA), believe that patients need to know about the risks but say the benefits mean the drugs should remain on the market.
It was in May that a study showed that Humira, known generically as adalimumab, and Remicade, known generically as infliximab, tripled the risk of cancer, particularly lymphoma, and some infectious diseases such as tuberculosis in patients who used them.
The information had already been included in labels put on the drugs after a directive from the FDA six months earlier.
Dr. Eric L. Matteson, a professor of medicine at the Mayo Clinic, New York and colleagues who did the original study, later re-analyzed the data and added more from other studies they had not considered before; the new analysis showed the cancer risk was 2.4 times greater among patients who used the drugs, and the risk of infectious disease was 1.8 times greater.
Matteson says though the risk is still higher in treated groups than in untreated groups, that is to some extent to be expected as rheumatoid arthritis is an autoimmune disease, in which the immune system mistakenly attacks the joints, and the drugs target TNF-alpha, one of the immune system's signaling compounds.
Matteson says anything that modifies the immune systems has the potential for causing cancers.
Matteson's team is now looking at a third drug in the same class, which they are also concerned about, Enbrel (Amgen), known generically as etanercept.
So far, studies have shown no link between Enbrel and cancer or infectious diseases.
Rheumatoid arthritis affects about 2 million Americans and the drugs approved to treat it often work against skin conditions such as psoriasis, ulcerative colitis and similar autoimmune conditions.
On another issue connected to Matteson's May study, the failure of researchers to fully disclose pharmaceutical-industry connections in the study has resulted in a letter of apology to the Journal of the American Medical Association - JAMA.
Fortunately all those involved in the issue regard both the findings of the study and the methods used as sound and there appears to be no question as to the validity of the science involved.