Evaluation of HU-resistance in Adult Patients With Polycythemia Vera Who Meet PV-AIM Predictors

Inclusion Criteria:

1. Signed informed consent must be obtained prior to participation in the study

2. Confirmed diagnosis of Polycythemia vera (according to WHO 2008, 2016, or 2022criteria)

3. Eastern Cooperative Oncology Group (ECOG) ≤ 2

4. No previous pharmacologic cytoreductive therapy (including investigational drugs)

5. No phlebotomy in last 14 days

6. HU-eligible

• High-risk: age ≥ 60 years and/or prior history of thrombosis

• Low-risk: showing at least one of the defined criteria

• Signs of disease progression (myeloproliferation)

• Increasing risk of thromboembolism and bleeding:

7. Female participants of childbearing potential should have a negative serum pregnancytest within 72 hours prior to receiving the first dose of study treatment.

Exclusion Criteria:

1. Patients with post- polycythemia vera myelofibrosis (post-PV MF) or acceleratedphase/ blast phase myeloproliferative neoplasm acute myeloid leukemia (AP/BP-MPNAML)

2. Patients with a contraindication to HU according to the SmPC (severe bone marrowdepression, leukopenia (< 2.5 x 109 leukocytes/l), thrombocytopenia (< 100 x 109platelets/L), severe anemia (< 10 g/dL HGB)

3. Patients with rare hereditary galactose intolerance, total lactase deficiency orglucose-galactose malabsorption in their past medical history

4. Active uncontrolled infection that is considered by the Investigator as a reason forexclusion

5. Active malignancies (except for carcinoma in situ; prostate cancer and breast cancerin remission and - where necessary- ongoing hormonal therapy)

6. Inadequate liver function as assessed by Investigator

7. Inadequate renal function as demonstrated by Modification of Diet in Renal Diseaseestimate glomerular filtration rate (MDRDeGFR) < 30 mL/min/1.73m2 or on dialysis

8. Pregnant or nursing (lactating) women, where pregnancy is defined as the state of afemale after conception and until the termination of gestation, confirmed by apositive human chorionic gonadotrophin (hCG) laboratory test.

9. Sexually active males unwilling to use a condom during intercourse while takingstudy treatment and for at least 6 months after stopping study treatment.

10. HIV patients treated with nucleoside reverse transcriptase inhibitors likedidanosine and stavudine

Other inclusion/exclusion criteria may apply