AstraZeneca cancer drug carries toxic risks: FDA
An experimental drug developed by the pharmaceutical company AstraZeneca to treat thyroid cancer carries "substantial toxicity" risks, the US Food and Drug Administration warned on Tuesday.
A total of 31 percent of patients taking the drug, vandetanib, experienced serious side effects compared to 13 percent who did while taking a placebo.
Eighty percent of patients in a Phase II study that began with a 300 milligram dose of the drug "required a dose reduction or interruption," the FDA added in a report ahead of a meeting of outside experts to discuss the findings on December 2.
A subsequent study that gave patients a 100 milligram dose of the drug saw 21 percent require a dose reduction or interruption.
"Given the substantial toxicity seen with vandetanib, should its indication be limited to patients with progressive, symptomatic medullary thyroid cancer?" the FDA asked. "Should additional doses of vandetanib be explored?"
The FDA does not have to follow the recommendation of the expert panel but it often does.
Side effects included a potentially dangerous skin rash known as Stevens-Johnson syndrome, strokes and lung disease.
AstraZeneca expects to have a decision by January on its new drug application for the use of vandetanib in patients with medullary thyroid cancer, a relatively rare disease. Some 45,000 new cases will be diagnosed in 2010 in the United States.
The company says the drug works by slowing tumor growth.
Vandetanib was initially set to be a treatment for lung cancer but AstraZeneca withdrew its request for the drug to be put on the market for such use in 2009 after studies showed it failed to extend survival rates.
© 2010 AFP