US FDA ordered Amgen Inc on Wednesday to change the labels for Aranesp and similar anemia drugs to address concerns about the risks to cancer patients.

The FDA ordered the new labels to say that the drugs shouldn’t be used in cancer patients receiving chemotherapy. The changes apply to Amgen’s Aranesp and Procrit, which is sold by Johnson & Johnson under a license from Amgen. The drugs are known as as erythropoiesis-stimulating agents, or ESAs, made by the companies.

This is the first time the agency is using authority granted to it in 2007 to force a drug maker to change a drug’s label. Aranesp has been under review by U.S. health officials since it was tied to a greater risk of heart attack, stroke and death at high doses in cancer patients nearly two years ago. Studies suggested that the drugs could promote cancer growth in certain patients and accelerate their death.

Amgen said in a statement the label changes were consistent with the company’s expectations and the potential impact was factored into guidance issued on Monday.

“This label is consistent with our expectations....We will soon be communicating the revised product labeling for ESAs to both physicians and patients,” an Amgen spokesman said.

Johnson & Johnson, of New Brunswick, N.J., said it will cooperate with the FDA to implement the new label.

Shares of Johnson & Johnson fell 40 cents to close at $68.08 on the New York Stock Exchange. Shares of Amgen rose 2 cents, to $62.30 Wednesday, near their 52-week high.