Combination of Tagraxofusp With Pacritinib in Patients With Intermediate-1 or Higher Myelofibrosis, Who Have Had Prior Therapy With the Approved JAK Inhibitors or in Which Therapy With the Approved JAK Inhibitors is Not Appropriate, Contraindicated or Declined

The goal of this open-label, single-center, pilot trial is to test the combination of Tagraxofusp (TAG) with Pacritinib (PAC) in patients with intermediate-II or higher myelofibrosis (MF), who have had prior therapy with the approved JAK1/2 inhibitor or in which therapy with the approved JAK1/2 inhibitors is not appropriate, contraindicated or declined by the subjects.

The Primary Objective is to:

1\. Characterized efficacy of the combination of Tagraxofusp and Pacritinib.

The Secondary Objective is to:

1\. characterize the safety profile of the combination Tagraxofusp and Pacritinib.

2, Characterize the feasibility of the combination Tagraxofusp and Pacritinib. 3. Characterize hematologic improvement with the combination Tagraxofusp and Pacritinib.

4\. Evaluate and compare the effect of Tagraxofusp and Pacritinib on participant reports of MF symptoms.

Exploratory:

Pharmacokinetic (PK) testing of Tagraxofusp and Pacritinib to assess clinical predictors of response.

Next Generation Sequencing (NGS) Testing to define the number and the allele burden of pathological mutations, as well as the changes over the course of therapy, both in regard to progression and response.

Blood will be collected and stored at KU BRCF for future study related PK analysis