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Organic Chemistry II 202 - DDB - 05 CAM Aranesp By Matthew Seidler (0588687) Winter 2007 John Abbott College Overview • Introduction • What is it? • History • Structure/Chemistry • Benefits/Risks • Competitors • Personal Thoughts Red Blood Cells • • • Transport oxygen to various parts of the body • Oxygen = NP, Blood = P • Need a way to transport oxygen Divide rapidly When your body makes fewer RBCs, anemia develops What exactly is Aranesp? • Darbepoetin alfa is a synthetic form of erythropoietin • Erythropoietin = produced by kidney, hormone that stimulates RBC production • Stimulates erythropoiesis (process by which erythrocytes (RBCs) are produced when oxygen is low (hypoxia) • Stimulates bone marrow to produce RBCs • When is oxygen supply lowered? • Exercise • High altitudes, etc How EPO works • EPO binds to receptors (EpoR) in bone marrow to speed up mitosis of cells responsible for making RBCs • Oxygen in blood rises, EPO production slows down EPO Amgen, Inc. • International Biotech company in California • The largest independent biotech firm, 15K staff members • As of 09/06, Amgen had eight FDA approved drugs (one of which was Aranesp) Back to the drug… • 09/01: approved by FDA for treatment in anemia in patients with chronic renal failure • Kidneys secrete erythropoetin, which stimulates RBC production • Patients w/ renal failure commonly suffer from anemia (lower RBC count) • 06/01: approved by European Medicines Agency for the same treatments, but also for anemia patients undergoing chemotherapy • Chemotherapy affects rapidly dividing cells (I.e. RBCs) • You therefore need more erythropoetin in order to stimulate RBC production Another Use • Patients who require a blood transfusion or have surgery where blood loss is expected, EPO is given in advance • If blood is lost in surgery… How is it made? • Produced by recombinant DNA technology in modified Chinese hamster ovary cells • Differs from real erythropoietin (EPO) in that it has two more N-linked oligosaccharide chains • Why not just use real EPO? Chemistry of the drug • C815H1317N233O241S5 • Ok, let’s draw it. IHD = 1/2(2*815+2…) • Molar mass = 18396.1 g/mol Anemic Cancer Patients • 01/07, Amgen wrote a letter that highlighted the results from a recent anemia of cancer trial, and warned doctors • They informed the FDA that control over the cancer was worse in patients on Aranesp (against those who weren’t on the drug) What did the FDA say? • Released a public health advisory, in March 07, and a clinical alert for doctors about the use of erythropoeisis-stimulating agents such as epogen and darbepoeitin • Use caution when using these drugs in cancer patients • Lack of clinical evidence to support improvements in these situations Risks • Increases the risk of… • Cardiovascular problems (RBCs increases viscocity of blood) • • • • • • • • • Strokes Hypertension Congestive heart failure Myocardial infarction (heart attack) Hypertension Seizures (why?) Vascular thrombosis (clot inside blood vessel) Edema (fluid collecting in cavities of body) (why?) Side effects = fever, chest pains, nausea, etc $10 000/ yr for drug (dialysis patient) $12 000/ yr for drug (chemo patient) Sales: $10 B in 2004 Abuse • Cross country skiers Larisa Lazutina & Olga Danilova of Russia and Johann Muhlegg of Spain EPO as a blood doping agent • Used by healthy athletes to give a competitive advantage • Increases oxygen carrying capacity of the blood • Therefore, increases aerobic respiratory capacity of the muscles • Helps make more ATP Continued • Useful for bicycle races (offsets decrease in RBC count that occurs over several races) • What happens if you OD? • The drug can produce so many RBCs that the blood thickens and strains the heart (I.e. during sleep when HR is low) Competitors • From Amgen: Epogen & Aranesp (Brand names) • There’s also Dynepo Dynepo • Pharmaceutical EPO under development by Shire Pharmaceuticals • Launched in Europe in 2006 • Amgen patents prevent it from launching here • Instead of being made from cultured animal cells, it’s made from cultured human cells Dynepo • Has a true form of sialic acid & oligosaccharide residues • This makes it longer lasting than Amgen’s products (this is not confirmed yet…) • Undetectible in urine tests for EPO that is used on athletes Personal Thoughts • Jehova’s Witnesses • Drug can be used for many things QUESTIONS?