Drugs Xagena
The FDA ( Food and Drug Administration ) has approved revised boxed warnings and other safety-related product labeling changes for erythropoiesis-stimulating agents ( ESAs ), which treat certain types of anemia. These new statements address the risks that the drugs Aranesp ( Darbepoetin alpha ), Epogen and Procrit ( Epoetin alpha ) pose to patients with cancer and patients with chronic kidney failure.
The labeling changes, which incorporate advice from FDA Advisory Committees and expand upon labeling changes made in March 2007, also include a statement that symptoms of anemia, fatigue and quality of life have not been shown to improve in patients with cancer who are treated with ESAs.
Epogen, Procrit and Aranesp are approved to treat anemia in patients with chronic kidney failure and anemia caused by chemotherapy in certain patients with cancer.
Epogen and Procrit are also approved for use in certain patients with anemia who are scheduled to undergo major surgery to reduce blood transfusions during or shortly after surgery and for the treatment of anemia caused by Zidovudine ( AZT ) therapy in HIV patients.
For patients with cancer
For patients with cancer, the new boxed warnings emphasize that ESAs caused tumor growth and shortened survival in patients with advanced breast, head and neck, lymphoid and non-small cell lung cancer when they received a dose that attempted to achieve a hemoglobin level of 12 grams per deciliter ( g/dL ) or greater.
The boxed warnings also emphasize that no clinical data are available to determine whether there is a similar risk of shortened survival or increased tumor growth for patients with cancer who receive an ESA dose that attempts to achieve a hemoglobin level of less than 12 g/dL. This is the hemoglobin level commonly achieved in clinical practice.
Health care providers determine whether a patient is anemic and decide on ESA dosing by measuring how much of the protein known as hemoglobin is present in a patient's red blood cells.
An earlier boxed warning, approved in March, described the results of six studies demonstrating that survival was shorter and tumors progressed faster when ESAs were used to achieve hemoglobin levels of 12 g/dL or greater in cancer patients.
New boxed warning also clarifies that ESAs should only be used in patients with cancer when treating anemia specifically caused by chemotherapy and not for other causes of anemia. Moreover, it states that ESAs should be discontinued once the patient's chemotherapy course has been completed.
For patients with chronic kidney failure
For patients with chronic kidney failure, the new boxed warning states that ESAs should be used to maintain a hemoglobin level between 10 g/dL to 12 g/dL. Maintaining higher hemoglobin levels in patients with chronic kidney failure increases the risk for death and for serious cardiovascular reactions such as stroke, heart attack or heart failure, the boxed warning states.
In addition to the boxed warning, the new labeling provides specific instructions for dosage adjustments and hemoglobin monitoring for chronic kidney failure patients who do not respond to ESA treatment with an adequate increase in their hemoglobin levels.
The new labeling also emphasizes that there are no data from controlled trials demonstrating that ESAs improve symptoms of anemia, quality of life, fatigue, or patient well-being for patients with cancer or for patients with HIV undergoing AZT therapy.
In March 2007 the FDA approved labeling changes and issued a public health advisory outlining the new safety information about ESAs. Safety concerns regarding ESAs were discussed during May 2004 and May 2007 meetings of FDA's Oncologic Drug Advisory Committee and a September 2007 joint meeting of FDA's Cardiovascular and Renal Drugs Advisory Committee and the Drug Safety and Risk Management Advisory Committee. ESA product labeling was previously revised in 1997, 2004 and 2005 to reflect new safety information.
The FDA is currently reviewing a proposed Medication Guide that will better communicate the safety and effectiveness of ESAs to patients and will replace the existing patient labeling.
ESAs are a bioengineered version of a natural protein made in the kidney that stimulates the bone marrow to produce more red blood cells.
Source: FDA, 2007
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