UPDATE 1-FDA adds survival warning to anemia drug labels

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LOS ANGELES, March 7 (Reuters) - The U.S. Food and Drug Administration ordered that "black box" warnings on the labels of Amgen Inc's (AMGN.O) Aranesp and other anemia drugs now note the drugs have been shown to impair survival in certain cancer patients, Amgen said on Friday.

The strongest-possible warning states the drugs shortened overall survival, or caused more rapid tumor growth, in clinical studies in patients with breast, non-small cell lung, head and neck, lymphoid and cervical cancers, when given at high doses.

Mark Schoenebaum, an analyst at Bear Stearns, said in a research note he views the changes as minor since cervical cancer is an extremely small part of Aranesp sales and the label already contains negative survival data from other breast cancer trials.

The FDA a year ago first affixed a warning to the labels of Aranesp, as well as Amgen's Epogen and Johnson & Johnson's (JNJ.N) Procrit, after studies showed an increased risk of death for some patients.

Over the past year, there has been a steady drumbeat of negative news about the drugs, which are genetically-engineered versions of a protein that boosts production of oxygen-carrying red blood cells.

Sales of Aranesp, Amgen's top-selling product, fell 12 percent last year to $3.6 billion, while sales of Procrit, which is less important to J&J's bottom line, fell 9.4 percent to $2.9 billion.

The so-called erythropoiesis-stimulating agents (ESAs) are approved to treat anemia in patients with chronic kidney failure and in cancer patients undergoing chemotherapy. (Reporting by Deena Beasley, editing by Leslie Gevirtz/Andre Grenon)