AOP2014 vs. BAT in Patients With Polycythemia Vera Who Previously Participated in the PROUD-PV Study.

Polycythemia Vera (PV) is a disease of bone marrow stem cells that manifests in a drastic increase of red blood cells and frequently also of white blood cells. The "thickening" of the blood in relation with a modified function of the cells has several consequences like increased blood pressure, pruritus of the skin, fatigue, disturbed blood circulation in the brain as well as fingers and toes and an increased risk of arterial and venous thrombosis (thrombosis is the formation of a blood clot in a vessel); like stroke, cardiac infarction, deep vein thrombosis in the legs. In case of a strong increase of platelets there is an additional risk of bleedings. As the disease progresses the size of spleen and liver increased in most cases and the bone marrow shows signs of fibrosis. In some cases of PV a progression at a later time point to a leukemia (increased formation of white blood cells) can occur. The aim of this study is to show that the study drug AOP2014 (pegylated proline interferon alpha-2b) has the long term efficacy and safety in controlling the disease. A comparison arm is receiving best available therapy as selected by the investigator. Response to the treatment is measured by several blood parameters as well as size of the spleen. Interferon-alpha has been shown to be effective in controlling the blood parameters by immunologically influencing the blood building cells. This can lead to a suppression of the disease-causing stem cells and help healthy stem cells to proliferate. Through this mechanism it is possible that Interferon-alpha can avoid long-term damaging effects of the disease.