Test may predict cancer response to anemia drugs

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."

Blau emphasized that the findings were preliminary and need to be confirmed with a larger analysis of tumor specimens.

Dr. Julie Gralow, a breast cancer specialist at the University of Washington, called the results "very exciting" and said if the findings hold up, they "may mean we can use ESAs in a targeted way."

Baynes said Amgen has done extensive studies and has discovered no evidence that levels of erythropoietin receptor messenger RNA have any bearing on cancer tumors.

Amgen and J&J are awaiting final word from the U.S. Food and Drug Administration on whether the drugs' labels should be changed following an advisory committee's recommendation earlier this year they not be given to cancer patients undergoing treatment that could cure their disease, or to patients with advanced breast cancer or head and neck cancer.

(Editing by Tim Dobbyn)