Amgen details higher death risk in Aranesp trial
Last Updated: 2007-04-16 16:08:09 -0400 (Reuters Health)
By Deena Beasley
LOS ANGELES (Reuters) - Amgen Inc. on Monday said 48.5 percent of cancer patients not undergoing chemotherapy or radiation who received its anemia drug Aranesp in a clinical trial died compared with 46 percent of patients on placebo as the company released details of a previously reported study.
Amgen, which had disclosed the higher Aranesp death rate in January, beginning a slide in the company's share price, released full data from the trial at a meeting of the American Association for Cancer Research.
The company had also reported in January that the study did not meet its primary goal of showing Aranesp could reduce the need for blood transfusions in those patients.
Amgen said the results suggest the risk of taking Aranesp is not justified for patients with unexplained anemia and active cancer -- those who are not in remission and not receiving chemotherapy -- and it would no longer seek approval for the condition known as anemia of cancer.
However Dr. John Glaspy, one of the study's researchers, said, "there is no clear explanation for the increase of deaths in the Aranesp group."
Some doctors have expressed concern that anemia drugs like Aranesp, which are forms of the red blood cell-boosting protein erythropoietin, may actually feed the growth of tumors.
"Since erythropoietic agents are sometimes used in the U.S. to treat anemia and reduce transfusion risk in patients not on chemotherapy, these results are of concern to the research and clinical cancer communities," Glaspy, a professor at the University of California, Los Angeles, said in a statement.
Aranesp, a longer-lasting version of Amgen's older anemia drug Epogen, is approved for use in patients with chronic kidney disease and for cancer patients whose anemia is caused by chemotherapy.
While chemotherapy-induced anemia is the drug's primary use, Amgen said off-label use in anemia of cancer accounted for about $560 million of Aranesp global sales last year.
The phase III study involved 985 patients, mostly from Central and Eastern Europe, who were treated with Aranesp, which is given by infusion, or a placebo.
Patients were treated for 16 weeks and followed for 2 years. During the study, Aranesp was withheld if the patient's hemoglobin count exceeded 13 grams per deciliter.
Amgen said that even after adjusting for factors such as gender, those who had the most advanced stage of cancer and prior treatment, there was a higher death rate for the Aranesp group. But after taking into account factors such as the patient's degree of illness and tumor type, the statistical significance diminished, the company said.
The researchers noted that Aranesp patients with kidney, prostrate, or stomach cancers, non-Hodgkin's lymphoma or multiple myeloma appeared to have worse survival outcomes, but the opposite was seen for patients with breast, colon, ovarian, or cervical cancer.
The U.S. Food and Drug Administration last month slapped a strong new warning on the label of Aranesp and similar anemia drugs calling on doctors to use the lowest dose that can effectively avoid the need for blood transfusions.
