Pacritinib Effectiveness in Real-world Settings

Inclusion Criteria: * Adult patients must be ≥18 years of age at the index date * Patients diagnosed with MF with platelet counts ≥50 x 109/L at the time of treatment initiation with pacritinib. If multiple values are available within 30 days prior to initiating treatment with pacritinib will use the value closest to index date * Patients will be required to have ≥1 month of treatment with pacritinib and ≥6 months of observation from the start of pacritinib unless the patient died within 6 months of starting pacritinib * If peripheral blasts were evaluated prior to index, they must be \<10%. If not evaluated, patients will be included unless a healthcare provider has indicated in the medical record that there is a concern that the patient has transitioned to accelerated/blast phase disease at or prior to index * According to local regulations, waivers of consent will be sought for study patients from the appropriate regulatory authorities and/or the independent ethics committee (IEC)/institutional review board (IRB). For patients not covered by waivers of consent, signed and dated informed consent provided by the patient, or the patient's legally authorized representative(s) for patients under the legal age (with patient assent, as applicable), should be obtained before any study-related activities are undertaken. Exclusion Criteria: * Diagnosis of acute myeloid leukemia prior to index * Physician-concern that the patient has transitioned to accelerated/blast phase disease if peripheral blasts were not evaluated * Treated with 2 or more JAK inhibitors prior to initiating treatment with pacritinib * Treated with pacritinib in a clinical trial setting