Oral Pacritinib Versus Best Available Therapy to Treat Myelofibrosis With Thrombocytopenia


  • Study type

  • Study phase

  • Study IDs

  • Describes the nature of a clinical study. Types include:

    • Observational study — observes people and measures outcomes without affecting results.
    • Interventional study (clinical trial) — studies new tests, treatments, drugs, surgical procedures or devices.
    • Medical records research — uses historical information collected from medical records of large groups of people to study how diseases progress and which treatments and surgeries work best.
  • During the early phases (phases 1 and 2), researchers assess safety, side effects, optimal dosages and risks/benefits. In the later phase (phase 3), researchers study whether the treatment works better than the current standard therapy. They also compare the safety of the new treatment with that of current treatments. Phase 3 trials include large numbers of people to make sure that the result is valid. There are also less common very early (phase 0) and later (phase 4) phases. Phase 0 trials are small trials that help researchers decide if a new agent should be tested in a phase 1 trial. Phase 4 trials look at long-term safety and effectiveness, after a new treatment has been approved and is on the market.

  • Site IRB
    • Scottsdale/Phoenix, Arizona: 14-000507
    NCT ID: NCT02055781
    Sponsor Protocol Number: PAC326

About this study

The primary hypothesis of the study is that treatment with either once-daily or twice-daily pacritinib results in a greater proportion of patients with thrombocytopenia and myelofibrosis achieving ≥ 35% reduction in spleen volume from baseline to Week 24 than treatment with Best Available Therapy, and a greater proportion of patients achieving a ≥ 50% reduction in total symptom score from baseline to Week 24 as measured by the Myeloproliferative Neoplasm Symptom Assessment Form 2.0.

Participation eligibility

Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. If you need assistance understanding the eligibility criteria, please contact the study team.

See eligibility criteria

Inclusion Criteria:

  • Intermediate -1 or -2 or high-risk Myelofibrosis (per Passamonti et al 2010)
  • Thrombocytopenia (platelet count ≤ 100,000/µL) at any time after signing informed consent
  • Palpable splenomegaly ≥ 5 cm on physical examination
  • Total Symptom Score ≥ 13 on the MPN-SAF TSS 2.0, not including the inactivity question
  • Patients who are platelet or red blood cell transfusion-dependent are eligible
  • Adequate white blood cell counts (with low blast counts), liver function, and renal function
  • At least 6 months from prior splenic irradiation
  • At least 1-4 weeks since prior myelofibrosis therapy, including any erythropoietic or thrombopoietic agent
  • Not pregnant, not lactating, and agree to use effective birth control
  • Able and willing to undergo frequent MRI or CT assessments and complete symptom assessments using a patient-reported outcome instrument

Exclusion Criteria:

  • Prior treatment with more than 2 JAK2 inhibitors or with pacritinib
  • More than 6 months of cumulative prior JAK2 inhibitor treatment
  • History of (or plans to undergo) spleen removal surgery or allogeneic stem cell transplant
  • Ongoing gastrointestinal medical condition such as Crohn's disease, Inflammatory bowel disease, chronic diarrhea, or constipation
  • Active bleeding that requires hospitalization during the screening period
  • Cardiovascular disease, including recent history or currently clinically symptomatic and uncontrolled: congestive heart failure, arrhythmia, angina, QTc prolongation or other QTc risk factors, myocardial infarction
  • Other malignancy within last 3 years other than certain limited skin, cervical, prostate, breast, or bladder cancers
  • Other ongoing, uncontrolled illnesses (including HIV infection and active hepatitis A, B, or C), psychiatric disorder, or social situation that would prevent good care on this study
  • Life expectancy < 6 months

Participating Mayo Clinic locations

Study statuses change often. Please contact us for help.

Mayo Clinic Location Status Contact

Scottsdale/Phoenix, Ariz.

Mayo Clinic principal investigator

Ruben Mesa, M.D.

Open for enrollment

Contact information:

Cancer Center Clinical Trials Referral Office



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