A Study of Fedratinib With IDH Inhibition in Advanced-Phase, IDH-Mutated Ph-Negative Myeloproliferative Neoplasms

The purpose of this research is to gather information on the safety and effectiveness of fedratinib (a drug called a \"jak inhibitor\" ) in combination with ivosidenib or enasidenib (two anti-cancer drugs). While all three drugs are FDA-approved for various conditions, the US Food and Drug Administration (FDA) has not approved the combination of these drugs for the treatment of rare blood cancers that present Isocitrate dehydrogenase (IDH) mutations, and therefore these drugs can only be given in a research study.