Test may predict cancer response to anemia drugs

By Deena Beasley

CHICAGO (Reuters) - A genetic test may help predict whether giving cancer patients anemia drugs could make their cancer worse, U.S. researchers said on Sunday.

Over the past year and a half, eight late-stage clinical trials have shown that treatment with drugs known as erythropoiesis-stimulating agents, or ESAs, can have an adverse impact on cancer survival, the study's lead investigator, Dr. Anthony Blau at the University of Washington, told a meeting of the American Society of Clinical Oncology in Chicago.

Sales of the drugs -- Amgen Inc's Aranesp and Johnson & Johnson's Procrit -- have slumped in the wake of the safety concerns.

The drugs are genetically engineered forms of a protein that boosts production of red blood cells. They are used to treat anemia in patients with kidney disease and in cancer patients undergoing chemotherapy.

Blau's group measured levels of erythropoietin receptor messenger RNA in tumor samples from 101 patients with head and neck cancer who took part in a trial of Aranesp.

The aim was to test whether the drug might be acting on tumor blood vessels and other membranes as well as red blood cells, he said.

For the subset of patients treated with radiation therapy alone, without prior surgery, tumors with high-levels of this type of RNA messenger progressed faster in patients who received the anemia drug compared with patients given a placebo.

"There is really nothing new here," said Amgen vice president Roy Baynes. "There is not enough evidence to support or refute the theory."