A class of arthritis and psoriasis drugs, which includes Enbrel, Humira and Remicade, may be linked to an increased risk of skin cancer, according to a review of adverse events reported to the FDA last year.
In the latest edition of the Institute for Safe Medication Practices (ISMP)’s QuarterWatch report(PDF), which looks at data submitted to the FDA’s adverse event reporting system during 2012, investigators found a large number of cases of skin cancer among users of Humira, Remicade and Enbrel; a side effect not previously associated with the drugs.
According to the ISMP, the FDA received a combined total of 11,215 serious adverse event reports concerning the three drugs. While the largest number of reports, 3,324, dealt with the known problems involving infection risks, there were also 342 cases of skin cancer.
Humira, Enbrel and Remicade are tumor necrosis factor blockers, also known as TNF blockers, which are used for the treatment of rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, Crohn’s disease, moderate to severe chronic psoriasis and juvenile idiopathic arthritis, which was previously called juvenile rheumatoid arthritis. The medications are blockbuster treatments, with Humira alone generating sales of $6.5 billion in 2010.
In September 2008, the FDA issued a warning to health care professionals that TNF blockers carried the risk of fungal infections, including histoplasmosis, blastomycosis and coccidioidmycosis. Some of those infections could be life-threatening, the agency warned.
Many of the adverse event reports from 2012 were expedited reports from manufacturers. Drug makers have 15 days to report to the FDA any signs of new, serious adverse events which may not be adequately addressed on the drug label.
Humira, Enbrel and Remicade dominated that field last year, accounting for 75% of all expedited reports. Those reports most commonly involved infections, followed by reports of skin cancer, and then reports of demylination of nerve fibers; a disorder more commonly associated with Multiple Sclerosis.
“TNF also has a role in limiting cancer cells, and blocking it raised fears of increased cancer risk,” the report notes. “Although overall cancer rates are only modestly elevated in longer term studies, reports show unexpectedly large numbers of skin cancers reported for all three drugs.”
The report notes that many drugs used to treat serious problems also carry major risks. The question is always whether the risks outweigh the benefits, which can be a difficult question to answer when the drugs fight serious, debilitating and potentially deadly ailments.
In May, a Chicago jury deciding a Humira lawsuit refused to determine that Humira was defective due to its links to increased infection risk. However, the jury did order Abbott Laboratories to pay $2.24 million to the family of a woman who was seriously injured by an infection linked to Humira use, saying that the company should have done more to warn doctors about the risks.