Amgen Receives Complete Response Letter for Extended Dosing of Aranesp® for Patients with Chronic Kidney Disease and Anemia

Business Wire, Oct 13, 2006

THOUSAND OAKS, Calif. -- Amgen (NASDAQ:AMGN) today announced that the U.S. Food and Drug Administration (FDA) has issued a complete response letter, commonly referred to as an "approvable" letter, for Aranesp[R] (darbepoetin alfa) de novo once every-two-week and maintenance once-monthly dosing regimens for chronic kidney disease (CKD) patients with anemia not on dialysis.

In December 2005, Amgen submitted a biologics license supplement to the FDA for these Aranesp dosing regimens for CKD patients with anemia not on dialysis. The FDA has requested additional clinical data for the once-monthly dosing regimen, including an additional clinical study. The FDA has also requested additional label language and clarification of submitted data for the de novo once every-two-week dosing regimen. Amgen is committed to working closely with the FDA to resolve these questions in a timely and efficient manner.

About Anemia and Chronic Kidney Disease (CKD)

According to the National Kidney Foundation, CKD affects 20 million Americans (one in nine adults) and more than 20 million others are at increased risk for developing kidney disease. CKD is an irreversible condition characterized by kidney damage and impaired function that often progresses over time. Patients with CKD often suffer from serious complications such as anemia, which occurs when failing kidneys no longer produce sufficient erythropoietin, a hormone that stimulates the production of oxygen-carrying red blood cells. Red blood cells contain hemoglobin, a red, iron-rich protein that carries oxygen from the lungs to all of the body's tissues. Oxygen provides the energy the body needs for normal activities. Anemia occurs when the number of red blood cells (or the hemoglobin in them) falls below normal (12 to 18 g/dL of blood). Therefore, the body gets less oxygen and does not have enough energy to function properly.

About Aranesp

Amgen revolutionized anemia treatment with the development of Epoetin alfa, a recombinant erythropoietin (a protein that stimulates the production of oxygen-carrying red blood cells). Building on this heritage, Amgen developed Aranesp, a unique erythropoiesis-stimulating protein that can be dosed less frequently.

Aranesp was approved by the U.S. Food and Drug Administration (FDA) in September 2001 for the treatment of anemia associated with chronic renal failure (CRF), also known as CKD, for patients on dialysis and patients not on dialysis. In 2002, Aranesp was approved for the treatment of chemotherapy-induced anemia in patients with nonmyeloid malignancies in the U.S. and European Union (EU). Today, Aranesp is the only erythropoiesis-stimulating protein approved in the U.S. and EU for weekly and every-three-week administration, which allows physicians to synchronize anemia treatment with the majority of chemotherapy schedules. Since its introduction in 2001, more than 2 million CKD and chemotherapy patients with anemia have received treatment with Aranesp.

Important Safety Information

Aranesp is contraindicated in patients with uncontrolled hypertension. Erythropoietic therapies may increase the risk of thrombotic events and other serious events. Seizures have occurred in patients with Chronic Kidney Disease. The target hemoglobin (Hb) should not exceed 12 g/dL. If the Hb increase exceeds 1.0 g/dL in any 2-week period, dose reductions are recommended. In a study of Epoetin alfa treated hemodialysis patients with clinically evident cardiac disease, where the target hematocrit (Hct) was 42% (Hb = 14 g/dL), an increased incidence of thrombotic events and mortality was seen. The reason for increased mortality observed in this study is unknown. In a study with another erythropoietic product, in women with metastatic breast cancer receiving chemotherapy, where the target Hb was 12-14 g/dL, an increased incidence of thrombotic events, disease progression, and mortality was seen.

Cases of pure red cell aplasia (PRCA) and of severe anemia, with or without other cytopenias associated with neutralizing antibodies to erythropoietin have been reported in patients treated with Aranesp. This has been reported predominately in patients with CRF receiving Aranesp by subcutaneous administration. A sudden loss of response to Aranesp, accompanied by severe anemia and low reticulocyte count, should be evaluated. If anti-erythropoietin antibody-associated anemia is suspected, withhold Aranesp and other erythropoietic proteins. Aranesp should be permanently discontinued in patients with antibody-mediated anemia. Patients should not be switched to other erythropoietic proteins.

The most commonly reported side effects in clinical trials in patients with CRF were infection, hypertension, hypotension, myalgia, headache, and diarrhea. The most commonly reported side effects in clinical trials in patients with chemotherapy-induced anemia were fatigue, edema, nausea, vomiting, diarrhea, fever, and dyspnea.

About Amgen

Amgen discovers, develops and delivers innovative human therapeutics. A biotechnology pioneer since 1980, Amgen was one of the first companies to realize the new science's promise by bringing safe and effective medicines from lab, to manufacturing plant, to patient. Amgen therapeutics have changed the practice of medicine, helping millions of people around the world in the fight against cancer, kidney disease, rheumatoid arthritis, and other serious illnesses. With a broad and deep pipeline of potential new medicines, Amgen remains committed to advancing science to dramatically improve people's lives. To learn more about our pioneering science and our vital medicines, visit www.amgen.com.