Anaemia is a condition in which blood has a lower than normal number of red blood cells. It can also occur if red blood cells do not contain enough haemoglobin, an oxygen carrying part of blood. Anaemia is common in patients with chronic kidney disease. Healthy kidneys produce a hormone called erythropoietin, which stimulates the bone marrow to produce the proper number of red blood cells needed to carry oxygen to vital organs. Chronic kidney disease is a general term that means that the kidneys are not functioning to their full potential. The study drug, BAY85-3934, is being evaluated as a drug to increase the body's ability to produce erythropoietin.