Advances in the Treatment of BLOOD DISORDERS
Our bodies depend on small, specialized cells that make up blood to transport nutrients, gases, and waste products throughout our bodies. An imbalance of too many or too few specific cells can cause illnesses. Today's pharmaceutical innovations, however, are revolutionizing treatments for people with rare blood diseases.
Thrombocytopenia
Hemophilia B
Thrombocytopenia is caused by too few platelets in the blood, which are responsible for forming clots along with clotting factors if damage occurs to the blood vessels. Patients with this disorder bleed even with minor injuries, and in severe cases with no injury at all. This deficiency of platelets can be caused by a few factors, including low platelet production by the bone marrow, infection, other diseases, or sometimes drugs.85 Heparin, a drug used to prevent blood clots and to "thin" blood by inhibiting clotting factors in situations such as acute coronary syndromes including heart attacks, can cause thrombocytopenia in some patients.86
PHARMACEUTICAL ADVANCES
Alternative Blood-Thinning Treatment
In 1998, lepirudin was introduced as the first alternative to heparin for patients who experience heparin-induced thrombocytopenia. Lepirudin is a derivative of the saliva of a medicinal leech, a bloodsucking aquatic worm that is sometimes used in blood withdrawal. Lepirudin blocks thrombin, which is an enzyme that aids in clot formation. Lepirudin also promotes a rapid increase of platelets.87 The FDA estimates that 180,000 people could benefit from this new drug.88
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Hemophilia B is a rare congenital disorder caused by the lack of clotting Factor IX, a type of protein that works with platelets to form clots when damage to a blood vessel occurs. Hemophilia B affects approximately 18,000 Americans.89 People with this disease bleed excessively and for longer than other people. It can be life-threatening.
PHARMACEUTICAL ADVANCES
DNA-Derived Clotting Factor: A Better Treatment Option for Patients
Recombinant human Factor IX was approved in 1997 for the prevention and control of excessive, potentially life-threatening bleeding in hemophilia B patients. Recombinant DNA-derived clotting factors are lab-produced using Chinese hamster ovary cells that have been modified to express the human Factor IX gene.90 The advantage of recombinant human Factor IX over other sources of Factor IX is that it is free from the risk of transmitting human viruses.
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Endnotes:
85 Merck & Co., Inc., "Thrombocytopenia," The Merck Manual Online Medical Library: Home Edition for Patients and Caregivers, http://www.merck.com/mmhe/sec14/ch173/ch173d.html (accessed 14 July 2005).
86 S. Reents et al., Clinical Pharmacology, Gold Standard Multi-media, Inc., Heparin®, http://cp.gsm.com (accessed 14 July 2005).
87 Berlex Laboratories, Inc., "Product Overview," Refludan®, http://www.refludan.com/product/index.htm (accessed 15 July 2005).
88 Food and Drug Administration, Office of Orphan Products Development (OOPD), Approved Orphan Spreadsheet, available upon request from OOPD.
89 National Heart, Lung, and Blood Institute, What Is Hemophilia?, http://www.nhlbi.nih.gov/health/dci/Diseases/hemophilia/hemophilia_what.html (accessed 14 July 2005).
90 Food and Drug Administration, "New Recombinant Product for Hemophilia B," 11 February 1997, http://www.fda.gov/bbs/topics/ANSWERS/ANS00786.html (accessed 14 July 2005).
