The nationwide rate of severe allergic reactions to cetuximab is only about 2 percent. However, 22 percent of patients in this study showed severe allergic reactions to the drug. Cetuximab normally is infused over a two-hour period, but allergic patients had a reaction within minutes of starting the infusion, a classic anaphylactic reaction. The strongest predictor of a reaction to cetuximab was a history of other hypersensitivities, such as allergic asthma, food allergies, bee stings or allergies to other drugs, such as penicillin.
What is it about this strip across the middle South" A good question, said ONeil. The most likely places to look would be food- or plant-based allergens. If it is of plant origin, finding the source could be a needle-in-a-haystack search. And its a narrow geographic band; colleagues in Atlanta or the University of Virginia havent seen this type of reaction.
The research team felt that clinicians in this middle South region must obtain a thorough history of allergic reaction and be prepared to use an alternative drug, such as panitumimab, for patients with a history of hypersensitivity reactions, ONeil said.
Bristol-Myers Squibb is studying a screening test for the specific factor that leads to the reaction. In the meantime, doctors in the middle South need to be aware of, and be prepared to treat, sudden, severe allergic reactions when using cetuximab, ONeil said.
Based on the results of this study, UNC has a physician, physician assistant or nurse practitioner present for the first 30 minutes of all infusions of cetuximab. The Sarah Cannon Cancer Center halted all studies the drug.
|Contact: Les Lang|
University of North Carolina at Chapel Hill