Pegylated Interferon Alpha-2b Versus Hydroxyurea in Polycythemia Vera

Inclusion Criteria:

1. 18 years or older
2. Diagnosis of Polycythemia Vera according to the WHO 2008 criteria (Barbui et al, 2011) with the mandatory presence of JAK2V617F mutation as the major disease criterion.
3. For previously cytoreduction untreated patients - documented need of cytoreductive treatment

   \- leukocytosis (WBC\>10G/L for two measurements within one week)
4. For patients currently treated or pre-treated with HU, all of the following criteria:

   * being non responders (as defined by the response criteria for primary endpoint)
   * total HU treatment duration shorter than three years
   * no documented resistance or intolerance as defined by modified Barosi et al, 2009 criteria
5. Hospital Anxiety and Depression Scale (HADS) score 0-7 on both subscales
6. Patients with HADS score of 8-10 inclusive on either or both of the subscales may be eligible following psychiatric assessment that excludes clinical significance of the observed symptoms in the context of potential treatment with an interferon alpha
7. Signed written informed consent

Exclusion Criteria:

1. Any systematic cytoreduction for PV prior study entry with exception of HU for shorter than 3 years (see respective inclusion criterion)
2. Any contraindication to any of the IMPs (pegylated interferon or hydroxyurea) or their excipients
3. Any systemic exposure to a non-pegylated or pegylated interferon alpha
4. Documented autoimmune disease at screening or in the medical history
5. Clinically relevant pulmonary infiltrates, pneumonia, and pneumonitis at screening
6. Systemic infections, e.g. hepatitis B, hepatitis C, or HIV at screening
7. Known PV-related thromboembolic complications in the abdominal area (e.g. portal vein thrombosis, Budd-chiari syndrome) and/or splenectomy in the medical history
8. Any investigational drug less than 6 weeks prior to the first dose of study drug or not recovered from effects of prior administration of any investigational agent
9. History or presence of depression requiring treatment with antidepressant
10. HADS score equal to or above 11 on either or both of the subscales
11. Any risk of suicide at screening or previous suicide attempts
12. Any significant morbidity or abnormality which may interfere with the study participation
13. Pregnancy and breast-feeding females of reproductive potential and males not using effective means of contraception
14. History of active substance or alcohol abuse within the last year
15. Evidence of severe retinopathy (e.g. cytomegalovirus retinitis, macular degeneration) or clinically relevant ophthalmological disorder (due to diabetes mellitus or hypertension)
16. Thyroid dysfunction not adequately controlled
17. Patients tested positively with TgAb and / or TPOAb at screening
18. History of major organ transplantation
19. History of uncontrolled severe seizure disorder
20. Leukocytopenia at the time of screening
21. Thrombocytopenia at the time of screening
22. History of malignant disease, including solid tumours and hematological malignancies (except basal cell and squamous cell carcinomas of the skin and carcinoma in situ of the cervix that have been completely excised and are considered cured) within the last 3 years