['myeloproliferative neoplasm', 'primary myelofibrosis', 'essential thrombocythemia', 'polycythemia vera']
['mirabegron']

        Inclusion Criteria:

          -  Histologically or cytologically confirmed diagnosis of JAK2-V617F positive ET, PV or
             PMF at primary diagnosis or pretreated

          -  JAK2-V617F mutant allele burden > 20% in the peripheral blood at study entry

          -  Patient must give written informed consent before registration

          -  WHO performance status 0-2

          -  Age ≥ 18 years

          -  Adequate hematological values: neutrophils ≥ 1.5 x 109/L, platelets ≥ 100 x 109/ L

          -  Adequate hepatic function: bilirubin ≤ 1.5 x ULN, AST/ALT/AP ≤ 2.5 x ULN

          -  Adequate renal function (calculated creatinine clearance > 50 mL/min, according to the
             formula of Cockcroft-Gault)

          -  Women are not breastfeeding. Women with child-bearing potential are using effective
             contraception, are not pregnant and agree not to become pregnant during participation
             in the trial and during 28 days thereafter. A negative pregnancy test before inclusion
             (within 7 days) into the trial is required for all women with child-bearing potential.
             Men agree not to father a child during participation in the trial and during 28 days
             thereafter.

          -  Patient compliance and geographic proximity allow proper staging and follow-up.

        Exclusion Criteria:

          -  Leukemic transformation (>20% blasts in blood, marrow or extramedullary site)

          -  Diabetic neuropathy

          -  Severe or uncontrolled cardiovascular disease (congestive heart failure NYHA III or
             IV, unstable angina pectoris, history of myocardial infarction within the last twelve
             months, known cardiac rhythm disturbance including atrial fibrillation or QT
             prolongation

          -  Uncontrolled hypertension

          -  Treatment of ET, PV or PMF with IFNα or treatment of PMF with JAK inhibitors such as
             ruxolitinib within 3 months prior to trial entry.

          -  Previous malignancy within 5 years with the exception of adequately treated cervical
             carcinoma in situ or localized non-melanoma skin cancer.

          -  Psychiatric disorder precluding understanding of information on trial related topics,
             giving informed consent or interfering with compliance for oral drug intake.

          -  Treatment with hematopoietic stem cell transplantation

          -  Concurrent treatment with cytoreductive drugs, other experimental drugs or other
             anti-cancer therapy as well as treatment in a clinical trial within 2 months prior to
             trial entry.

          -  Any serious underlying medical condition (at the judgment of the investigator), which
             could impair the ability of the patient to participate in the trial (e.g. active
             autoimmune disease, uncontrolled diabetes, uncontrolled infection (HIV, Hepatitis B
             and C).

          -  Known hypersensitivity to trial drug or hypersensitivity to any other component of the
             trial drug.

          -  Any concomitant drugs contraindicated for use with the trial drug according to the
             approved product information.
      