FDA Issues Warning on ESAs
On March 9, the U.S. Food and Drug Administration (FDA) notified health care professionals of new safety information for drugs which stimulate red blood cell growth. The erythropoiesis-stimulating agents (ESAs) are Aranesp (darbepoetin alfa), Epogen (epoetin alfa), and Procrit (epoetin alfa). Four new studies in patients with cancer found a higher chance of serious and life-threatening side effects or death with the use of ESAs. These research studies were evaluating an unapproved dosing regimen, a patient population for which ESAs are not approved, or a new unapproved ESA. FDA believes these new concerns apply to all ESAs and is re-evaluating how to safely use this product class.
Complete information is available at http://www.fda.gov/medwatch/safety/2007/safety07.htm#ESA.
FDA Approves Lapatinib for Advanced Breast Cancer Patients
On March 13, FDA approved lapatinib (Tykerb), a new targeted anticancer treatment, to be used in combination with capecitabine (Xeloda) for patients with advanced or metastatic HER2-positive breast cancer. The combination treatment is indicated for women who have received prior therapy with other cancer drugs, including trastuzumab (Herceptin).
Lapatinib is a tyrosine kinase inhibitor that works through several molecular pathways to block the signals that tell tumor cells to grow. Unlike the monoclonal antibody trastuzumab - which is a large protein molecule that targets the part of the HER2 protein on the outside of the cell - lapatinib is a small molecule that enters the cell and blocks the activity of HER2 and other proteins from within. Because of this difference in mechanism of action, lapatinib works in some HER2-positive breast cancers that no longer respond to treatment with trastuzumab.
Additional information is available at http://www.fda.gov/bbs/topics/NEWS/2007/NEW01586.html.
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