FDA Eyes Safety of Popular Anemia Drugs
Chemo-Related Drugs May Spur Early Death in Cancer Patients and Others
Other studies showed no risk of dangerous heart problems with the drug and no signs that the drugs promote cancer. Overall FDA reviewers found four studies showing a higher risk of heart problems with EPO and three showing no increased risk.
Drug manufacturers defend their products, noting that large scale trials conducted in Europe show that EPO drugs have no impact on the overall survival rates of patients with lung cancer, lymphatic cancer, and other malignancies. While many studies have indicated an increased risk of blood clots in patients taking EPO, patients' overall life spans were not affected, says David Parkinson, MD, vice president for oncology clinical development for Amgen, Inc. The company makes the EPO drug Aranesp.
"We believe that our detailed examination confirms the safety profile of Aranesp," he says.
Parkinson referred to "a significant amount" of preliminary evidence showing that the drug could pose a measurable benefit to anemic patients on chemotherapy.
Both company and government officials agreed that more studies are needed to determine what effect EPO has on patients with different kinds of cancers, and whether or not the drug could actually have an effect directly on cancer cells, possibly causing them to grow.
American Volunteers Needed
Still, regulators and experts remain concerned that most if not all of the large EPO studies were performed in Europe and not the U.S. Officials expressed worry that American patients and their doctors may continue to shy away from signing up for trials where they could be randomized to take EPO or a placebo.
"The real question is, will they be willing to be randomly assigned," says Musa Meyer, a consumer advocate and member of the FDA's advisory panel for oncologic drugs. "I think there are physicians for whom it will be an issue."
Company officials said that several trials testing EPO drugs in patients with lung cancer, breast cancer, lymphoma, and head and neck cancers are continuing to recruit hundreds of patients. But those studies are all continuing in Europe.
"We will have those data very shortly," says Martine George, vice president for hematology and oncology research for Procrit maker Johnson and Johnson. Trials in the U.S. have largely ground to a halt because researchers have had trouble getting patients to sign up.