A Randomized Controlled Phase 3 Study of Oral Pacritinib Versus Best Available Therapy in Patients With Thrombocytopenia and Primary Myelofibrosis, Post-Polycythemia Vera Myelofibrosis, or Post-Essential Thrombocythemia Myelofibrosis


Phoenix/Scottsdale, Ariz.

Trial status:

Open for Enrollment

Why is this study being done?

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.

Who is eligible to participate?

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 - There is no maximum 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

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