WASHINGTON (AP) -- Medicare officials infuriated lawmakers and oncologists last year by limiting when the government would pay for anemia drugs used by cancer patients. Now, an advisory committee suggests even more limits on the drugs.

"I think it's been found that we seem to have done the right thing and indeed may need to go further," said Dr. Barry Straube, chief medical officer for the Centers for Medicare and Medicaid Services.

In July, Medicare determined that it would only reimburse doctors when they administered anemia medications to patients with hemoglobin levels below a certain threshold -- 10 grams per deciliter. Officials made the change after the Food and Drug Administration added stern warnings to the drugs' labels. The labels urged doctors to use the lowest possible dose to avoid the need for blood transfusions.

Typically, patients don't need blood transfusions unless they are in the range of 7 or 8 grams, Medicare officials reasoned, so a cap of 10 was deemed "reasonable and necessary." A normal level is above 12.

In its efforts to overturn Medicare's new reimbursement policy, Amgen Corp. spent more than $16 million on lobbying last year and nearly $700,000 on campaign contributions, according to the Center for Responsive Politics. Amgen manufactures all three of the anemia drugs involved -- Aranesp, Epogen and Procrit. Johnson & Johnson markets Procrit.

The aggressive lobbying campaign succeeded in generating numerous letters and speeches from lawmakers denouncing Medicare's actions and in legislation that would have voided the rule if passed.

But as lawmakers were protesting, the FDA was getting more worried that the anemia drugs actually may contribute to tumor growth and decrease survival rates for patients.

On Thursday, FDA's scientific advisers recommended that patients with breast cancer or head-and-neck cancers not take the drugs. Also, the panel urged limiting the drugs to patients with incurable forms of cancer, if they sign consent forms acknowledging the risk. The FDA isn't bound by its advisers' recommendations but usually follows them.

Dr. John Jenkins, the FDA's director of the Office of New Drugs, would not say whether the advisory panel justified or vindicated Medicare's reimbursement policies.

"We have been comfortable that their coverage decision was consistent with our understanding of the data and our understanding of what our labeling intended to communicate," Jenkins said.

Many outside observers agree that it's unlikely Congress will intervene and overturn Medicare's separate restrictions, which are more effective in limiting doctors' use of the drugs than label warnings.

"It's dead in the water and for very good medical reason," said Merrill Goozner of the Center for Science in the Public Interest.

Amgen officials said in an e-mail response to questions Friday that the company is deeply committed to patient safety and looks forward to working with CMS to align the agency's reimbursement policy with the latest updated label information.

Many doctors and consumer groups joined in the criticism last year when Medicare made its decision to restrict when it would pay for treatments. Amgen and J&J argued again Thursday that the safety problems cited by FDA have been inconsistently reported across dozens of studies. And they pointed out that only studies involving higher-than-recommended dosing levels showed significant safety risks.

The two drug companies have asked for more leeway from Medicare to reimburse doctors for maintaining hemoglobin levels up to 12. The Congressional Budget Office estimated that overturning CMS's decision could increase government spending by as much as $5.3 billion over the next decade.

Amgen estimates that 270,000 patients with anemia related to chemotherapy were treated with ESAs in 2007.

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