A Phase II Study of Re-treatment of Myelofibrosis Patients With Ruxolitinib/Jakavi After Treatment Interruption Due to Loss of Response and/or Adverse Event (ReTreatment Trial)

Inclusion Criteria:

- Confirmed diagnosis of PMF, PPV MF or PET-MF, irrespective of JAK2 mutational status
according to the 2008 revised International Standard Criteria

- Peripheral blast count < 10%

- Requires therapy for MF in the opinion of the investigator

- Received prior monotherapy treatment with ruxolitinib for at least 12 consecutive
weeks and experienced treatment interruption because of lossof response or adverse
event

- Patients adhering to the Screening phase assessments and undergoing a a
ruxolitinib-free washout period of a minimum of 1 week and a maximum of 8 weeks

- ECOG performance status 0, 1, 2, or 3

- Adequate bone marrow function

- Written informed consent

Exclusion Criteria:

- Patients not initially responding (primary resistance) to ruxolitinib therapy

- Patients who underwent a splenectomy or spleen radiation

- Patients currently scheduled for bone marrow transplant

- Patients who have discontinued ruxolitinib < 14 days prior to screening

- Patients who are not able to receive a starting dose of ruxolitinib of at least 15 mg
total daily dose

- Leukemic transformation

- Inadequate renal function

- Presence of clinically meaningful active bacterial, fungal, parasitic or viral
infection which requires therapy

- Previous history of Progressive Multifocal Leuko-encephalopathy (PML)

- Clinically significant cardiac disease or significant concurrent medical condition