The new label says that therapy shouldn't be initiated until red blood cell counts fall below 10 grams per deciliter of blood and it will no longer include an upper bound of 12 g/dl, which had been tantamount to declaring the drugs safe at that level for which, as the NYT's article points out, there is no evidence.

It has been pointed out why did it take since March, when an advisory committee recommended the changes, for the FDA to act? Despite authority in the last year's FDA reform law to order changes without company negotiations, Amgen had been pushing to exclude certain restrictions from the label change, specifically, including a ban on using the drugs for breast or head and neck cancers, which the advisory committee had also recommended. The companies won that battle.

But, the FDA left out the warning about tumor growth. For over a year now, regulators have been looking into suggestions that these drugs might fuel the growth of tumors. But much of that evidence comes from studies in which patients were treated more aggressively than the drugs' labels recommend. The FDA had said there was now "mounting evidence" of documented effects on tumor progression which require a reassessment of the net benefit of this class of drugs.

Dr. Charles Bennett, a professor at Northwestion University, who authored the most recent analysis of anemia drug risks, said "It's clear that these drugs were overused because sales dropped so dramatically in the past years without seeing reports of people dying in the streets.

At the 12th annual NCCN conference, an executive with United Health Group, pointed out that in reviewing records of patients who were prescribed the drugs, 44% of those patients had blood work-ups that would indicate they were not even anemic.

Until this revelation, the drugs had a combined sales of over $6 billion a year. After this issue had started to be reported, U.S. Oncology took an 8-10 million dollar hit in its first-quarter SEC report last year, including reduced pre-tax income due to lower use of anemia drugs.

The problem is that few drugs work the way oncologists think and few of them take the time to think through what it is they are using them for.