RPT-UPDATE 2-U.S. panel cautiously backs Amgen anemia drugs

(Repeats to more subscribers)

* FDA panel: drugs still help some non-dialysis patients

* Amgen, J&J drugs expected to see $4.5 bln in 2010 sales

* FDA considering label changes, additional studies

* Analyst sees potential 1 percent sales impact on Amgen

* Amgen shares close up 2.2 percent (Adds comment from panel, analyst reaction, share prices)

By Susan Heavey

WASHINGTON, Oct 18 (Reuters) - The U.S. Food and Drug Administration should not restrict the use of popular anemia drugs sold by Amgen Inc (AMGN.O) and Johnson & Johnson (JNJ.N) in patients with chronic kidney disease, U.S. medical advisers said on Monday.

The FDA's panel of outside experts said the drugs, which include Amgen's Aranesp and Epogen and J&J's Procrit, clearly have safety issues but that more data was needed.

The Amgen and J&J drugs are expected to generate $4.5 billion in sales in 2010, although sales have declined in recent years over concerns about overuse in certain patients and reimbursement restrictions.

Panel members voted 9-5 against limiting dosing of the drug, known chemically as darbepoetin alfa. Many cited the need for doctors to be able to make their own adjustments depending on a patient's need. Three panel members abstained.

The FDA's advisers also said use of the drug should not be restricted in kidney patients who are getting dialysis, or in any kidney patients who have a history of prior stroke.

"One size fits all ... does not apply here," said panelist and University of Texas medical professor Darren McGuire, who like many panelists cited the need for doctors to personalize dosing for individual patients.

U.S. health officials are reviewing use of the anemia drugs amid concerns about their overuse in kidney disease and cancer patients. New guidelines have already been set for their use in cancer patients with anemia caused by chemotherapy.

Analysts said Monday's vote essentially left current use of the drugs untouched, thus avoiding another potential hit to sales. Amgen shares closed 2.2 percent higher at $57.96 on Nasdaq, climbing after the panel's first positive votes.

The panel's votes were "a best case" for the companies, said Mark Schoenebaum, a biotech and pharmaceuticals analyst for ISI Group.

Several recent studies have raised questions about cardiovascular risks with the drugs, known as erythropoiesis-stimulating agents or ESAs. FDA is considering various label changes to address such safety issues as well as possible new studies.

ESAs are genetically engineered versions of a protein that boosts production of oxygen-carrying red blood cells.

Amgen officials defended the benefits of using ESAs, saying they can help patients avoid blood transfusions, which carry their own risks.

"The benefit/risk profile remains positive here," said Mark Pfeffer, a Harvard Medical School professor who spoke on behalf of the company.

Amgen has suggested label changes to address proper use of the drugs, including limiting use in non-dialysis patients, maintaining hemoglobin levels at between 10 and 12 grams per deciliter, and curbing use in patients who do not respond.

Physician groups and patients at the meeting also urged the panel to let doctors tailor dosing as they see fit.

Most FDA panelists said they the drugs concerned them, but that more data was needed to make big changes to dosing.

Still, other panelists urged the FDA to make changes to lessen aggressive use of the drugs.

"I think until there's more certainty ... a conservative approach should be taken," said panel member James Neaton, a professor of biostatistics at the University of Minnesota.

Amgen's Epogen is an older and shorter-lasting version of Aranesp used in kidney patients who are undergoing dialysis. The company licensed Epogen in part to Johnson & Johnson (JNJ.N), which sells it in the United States under the brand Procrit. Both Aranesp and Procrit are marketed for predialysis kidney disease and cancer patient use.

While concerns have hit sales, ESAs still bring in billions of dollars.

Aranesp garnered $4.1 billion in 2006 global sales and is expected to generate $2.5 billion in 2010, according to Thomson Reuters data. Sales of J&J's drug were $3.2 billion in 2006 and are expected to reach $2 billion this year, the data showed.

However, Sanford Bernstein analyst Geoffrey Porges said that only about $300 million of annual Aranesp sales come from treating U.S. chronic kidney disease patients.

He said if new FDA restrictions were to cut those sales by half, "Amgen's total revenue would only be negatively impacted by 1 percent." (Additional reporting by Bill Berkrot in New York and Toni Clarke in Boston. Editing by Carol Bishopric and Robert MacMillan)