Amgen anxiety ahead cancer study of anemia drug

By Toni Clarke - Analysis

BOSTON (Reuters) - Amgen Inc.(AMGN.O: Quote, Profile, Research, Stock Buzz), the world's biggest biotechnology company struggling with safety concerns over its best-selling drug, is facing one of the most critical junctures in its history.

Results expected in May from a trial of the anemia drug Aranesp are likely to provide the clearest indication to date of whether the drug -- and those like it -- speed the growth of cancer.

"It's been a long time since we've seen an event that is this pivotal for Amgen," said Eric Schmidt, an analyst at Cowen & Co.

Last week U.S. regulators instructed Amgen and Johnson & Johnson (JNJ.N: Quote, Profile, Research, Stock Buzz), which makes a rival product called Procrit, to add the strongest possible warnings to their products after trials showed they increased the risk of death when given for unapproved uses or at higher-than-recommended doses.

Physicians and investors have become increasingly concerned that Aranesp, together with other drugs that are versions of the natural protein erythropoietin, or EPO, may speed the growth of cancerous tumors even as they help anemia. The drugs are designed to boost levels of oxygen-carrying hemoglobin in red blood cells.

So far, however, no trial has definitively shown whether these drugs increase the risk of death when given at recommended doses. That is what Amgen's trial of the drug in small cell lung cancer patients, known as study 145, is designed to do.

"For the first time in human history we will have a randomized trial that asks the question, "what is the effect of erythropoietin agents on survival?" said John Glaspy, professor of medicine at the Jonsson Comprehensive Cancer Center at the University of California, Los Angeles.

The implications for Amgen are huge.