Pacritinib With Aza for Upfront Myelodysplastic Syndrome

This study will be conducted as a phase 1/2 study of safety and preliminary efficacy of pacritinib in combination with azacitidine for IPSS-M moderate low to very high risk MDS. Phase one will be a 3 + 3 design to assess the dose for the phase two portion. The phase two portion will employ a simon min-max two-stage design whereby fifteen patients will be enrolled in the first stage then ten more if at least two patients in stage one have a response. The dosing of pacritinib for the phase two study will be based on the phase one findings. Standard dosing of azacitidine will be used. A correlative study will be conducted in conjunction with the trial where the investigators will measure whole blood collected pre-treatment and at four days post-treatment to measure intracellular flow and phosflow to detect JAK/STAT, NF-κβ, and AKT/mTOR signaling in patient samples and how treatment affects these pathways.

Inclusion Criteria: * Individuals must meet all of the following inclusion criteria to be eligible to participate in the study: 1. Patients must have histologic evidence of intermediate to high-risk myelodysplastic syndrome defined as having an IPSS-M score of moderate low, moderate high, high or very high risk. This will be assessed based on evaluations performed prior to screening for trial. Of note, the most recent evaluation pre-trial may be used which does not have to necessarily be at diagnosis. 2. Subjects must have recovered from the toxic effects of any prior chemotherapy to ≤ Grade 1 (except alopecia). 3. Required screening visit laboratory values: CrCL ≥45; total bilirubin \