A Study of Low Dose Interferon Alpha Versus Hydroxyurea in Treatment of Chronic Myeloid Neoplasms

Inclusion Criteria: * Male or female \> 18 years of age * Newly diagnosed, or previously diagnosed untreated patients with ET, PV or PMF including prefibrotic myelofibrosis according to the WHO classification * Active disease defined by one of the following criteria: * need for phlebotomy * leukocytosis \> 10 mia/l * thrombocytosis \> 400 mia/l * constitutional symptoms (fatigue, weight loss, night sweats or fewer \> 38 degrees celsius) * Pruritus * splenomegaly causing symptoms * previous thrombosis Exclusion Criteria: * Fertile women without a negative pregnancy test * Other malignant disease within last 5 years * ECOG performance score \>/= 3 * Creatinine \> 2x ULN * Bilirubin \> 1.5x ULN * ALAT \> 3x ULN * Previous psychiatric disorder (depression) * active autoimmune disease * Uncontrolled thyroid disease