P1101 in Treating Patients With Myelofibrosis

Inclusion Criteria: * Evaluable myelofibrosis by IWG-MRT criteria including one or more of the following: * Spleen \>= 5 cm below the left costal margin * MPN-SAF total symptom score (TSS) \> 10 at baseline * Hemoglobin \< 10 g/dL * Confirmed diagnosis of myelofibrosis (primary myelofibrosis or myelofibrosis secondary to essential thrombocythemia or polycythemia vera) by World Health Organization (WHO) diagnostic criteria (3 major and 2 minor criteria: major criteria: megakaryocyte proliferation and atypia with either reticulin and/or collagen fibrosis, not meeting criteria for chronic myelogenous leukemia \[CML\], polycythemia vera \[PV\], myelodysplastic syndrome \[MDS\], or other myeloid neoplasm, JAK2V617F or other clonal marker or no evidence of reactive marrow fibrosis; minor criteria: leukoerythroblastosis, increased lactate dehydrogenase \[LDH\], anemia, palpable splenomegaly) * For cohort 1: early stage MF (low or intermediate 1 stage as defined by Dynamic International Prognostic Scoring System \[DIPSS\]) without currently available treatment options * For cohort 2: intermediate-2 or high risk MF patients as defined by DIPSS either not eligible for ruxolitinib or having failed under ruxolitinib * No prior treatment for myelofibrosis (for cohort 1 only) * Eastern Cooperative Oncology Group (ECOG) performance status (PS) 0, 1 or 2 * Platelet count \>= 100,000/mm\^3 (obtained =\< 14 days prior to registration) * Absolute neutrophil count (ANC) \>= 1000/mm\^3 (o…