Aug. 30 (Bloomberg) -- The largest group of U.S. cancer doctors asked Medicare to lift rules that restrict use of anemia drugs made by Amgen Inc. and Johnson & Johnson, arguing the policy interferes with treatment of patients.

The American Society of Clinical Oncology, an organization with 23,000 members, said it submitted a written request today that Medicare change the policy adopted last month. Another physician group, the American Society of Hematology, plans to join the challenge.

Amgen has lost $25 billion, or 27 percent, of its value this year after its anemia medicines Aranesp and Epogen were linked to heart risks. U.S. sales of Aranesp dropped 19 percent in the second quarter after the Food and Drug Administration warned doctors to use the lowest doses possible. Medicare followed the FDA action on July 30 with a policy requiring doctors to use lower doses than are approved in the agency's label.

The rules imposed by Medicare, the U.S. health program for the elderly and disabled, may limit ``physicians' ability to provide the care they judge most appropriate for their patients,'' said Joseph Bailes, chairman of the cancer group's government relations council, in an Aug. 3 letter to the Medicare agency. He asked Medicare to revise its decision ``to avoid continued confusion and uncertainty'' among doctors and patients.

`Roller Coaster'

The policy states that Medicare won't pay for Amgen's anemia drugs and Johnson & Johnson's Procrit when a patient's hemoglobin count exceeds 10 grams a deciliter of blood. The current prescribing information approved by the FDA says the drugs can be used at up to 12 grams a deciliter.

The American Society of Hematology, a Washington-based group of 15,000 physicians who specialize in blood disorders, has also objected to Medicare's policy. The new rules may allow an anemia patient to get the drug, then stop taking it after four weeks, and then relapse, the group said.

That situation could lead to a ``roller coaster'' of treatment starting and stopping several times, said Samuel Silver, chairman of the group's subcommittee on reimbursement, in a letter to Medicare Aug. 8.

``This is extremely difficult for both the patient and the physician,'' Silver wrote. ``In addition, the new system would require additional lab work and office visits.''

Challenge Medicare Rule

The hematology group also plans to formally challenge the Medicare rule in the next week, said Mila Becker, the association's director of government relations and practice, in a telephone interview.

To succeed, the physician groups will need to show that Medicare misinterpreted or ignored certain medical evidence when it crafted the rule, Becker said. The rule will remain in force while it is being re-examined, she said.

Amgen also has said it would pressure the Medicare agency to reconsider its stance. The world's largest biotech company received almost half of its $14.3 billion revenue in 2006 from Aranesp and Epogen.

The medicines stimulate production of oxygen-carrying red blood cells to counteract weakness and fatigue. They are prescribed for patients with anemia caused by cancer chemotherapy and for patients with chronic kidney disease.

To contact the reporter on this story: Luke Timmerman in San Francisco at ltimmerman@bloomberg.net

Last Updated: August 30, 2007 18:04 EDT