Amgen and Johnson and Johnson have strengthened warnings about the risks, including death and stroke, associated with their blockbuster anemia drugs.
While sales of the drugs have suffered since the Food and Drug Administration raised safety concerns earlier this year, analysts said Thursday's action could provide some relief since the labeling is not as restrictive as it could have been.
The new labeling applies to Amgen's Epogen and Aranesp and Johnson & Johnson's Procrit, which are used to treat the blood-disorder anemia in kidney-failure and chemotherapy patients.
A new boxed warning label, the most serious a drug can carry, emphasizes that cancer patients had increased risk of death and showed accelerated tumor growth when treated with elevated doses of the drug. In March, the FDA approved a less serious warning that described studies that showed the risks.
The FDA said it is still unclear whether cancer patients face the same risks even when using normal doses of the drugs. The companies said they hope to answer that question by conducting six additional studies in different types of cancer patients.
At the FDA's request, the companies also strengthened a warning that using the drugs in higher doses can increase risk of heart attack, stroke and death in kidney failure patients. The label cautions physicians that using higher-than-recommended doses of the drugs does not benefit patients. Many doctors have prescribed elevated doses with the assumption it improves patients' quality of life.
Wall Street analysts, including Cowen and Co.'s Eric Schmidt, viewed the news in a positive light, noting that the labeling stops short of telling doctors exactly how much of the drugs to use.
"Although the label encourages a minimum dose ... in cancer patients, it does not restrict dosing," Schmidt wrote in a research note.
The FDA's stance on dosing could help bolster Amgen and Johnson & Johnson's arguments that a policy set in place by Medicare officials earlier this year is overly restrictive.
The Medicare rule, which took effect in July, states that doctors will only be paid if they use low levels of the drugs. Industry and physicians have lobbied against the policy, arguing that patients sometimes need to be treated with higher doses.
Amgen said Thursday it would renew a request that Medicare overturn the dosing restriction, pointing out that the new FDA labeling leaves dosing at the discretion of physicians.
Amgen and Johnson & Johnson are the only companies in the U.S. that make the anemia drugs. The treatments, which are man-made versions of a human protein, accounted for $10 billion in revenue for these two companies last year.