This is a 2-part study. In Part 1, participants will be dosed at 2 different dose levels in order to select the RP2D for Part 2 of the study.



Eligible Ages
Over 18 Years
Eligible Genders
Accepts Healthy Volunteers

Inclusion Criteria

  • Diagnosis of primary MF meeting the 2016 WHO criteria for overt PMF or secondary MF (PPV-MF or PET-MF) meeting the 2008 IWG-MRT criteria. - At least Intermediate 1 risk MF according to the DIPSS. - Prior treatment with ruxolitinib and/or fedratinib monotherapy - Currently receiving ruxolitinib or fedratinib monotherapy for PMF or secondary MF. - Splenomegaly defined as palpable spleen at least 5 cm below the left costal margin or volume ≥ 450 cm3 on imaging assessed during screening. - Allogeneic stem cell transplant not planned. - Platelet is greater than or equal to 50 × 109/L at screening. - Ability to comprehend and willingness to sign a written ICF for the study. - Willingness to avoid pregnancy or fathering children.

Exclusion Criteria

  • Prior treatment with a JAK inhibitor other than ruxolitinib or fedratinib - Record of ≥ 10% myeloid blasts in the peripheral blood (on peripheral blood smear) or bone marrow prior to or at the time of screening - For participants on ruxolitinib or fedratinib, unable to be tapered from that treatment over the course of 14 days without corticosteroids, hydroxyurea, or other agents - Treatment with ruxolitinib, fedratinib or other MF-directed therapy (approved or investigational) within 2 weeks of Day 1 - Prior splenectomy or splenic irradiation within 6 months before receiving the first dose of itacitinib - Unable or unwilling to undergo serial MRI or CT scans for spleen volume measurement - Unable or unwilling to complete MFSAF v4.0 diary on a daily basis during the study - ECOG performance status ≥ 3 - Life expectancy less than 24 weeks - Not willing to receive RBC or platelet transfusions - Participants with laboratory values at screening outside of protocol defined ranges - Significant concurrent, uncontrolled medical condition - Participants with impaired cardiac function or clinically significant cardiac disease unless approved by medical monitor/sponsor - History or presence of an abnormal ECG that, in the investigator's opinion, is clinically meaningful - Chronic or current active infectious disease requiring systemic antibiotics, antifungal, or antiviral treatment. - Evidence of HBV or HCV infection or risk of reactivation - Known HIV infection.

Study Design

Phase 2
Study Type
Intervention Model
Sequential Assignment
Primary Purpose
None (Open Label)

Arm Groups

ArmDescriptionAssigned Intervention
Part 1 : Dose Escalation of itacitinib
Participants will be dosed at different dose levels with a maximum of up to 9 participants per dose level.
  • Drug: itacitinib
    itacitinb Immediate Release (IR) will be dosed orally twice a day
    Other names:
    • INCB039110
Part 2 : Dose Expansion of itacitinib
Participants will be dosed at the recommended Phase 2 dose (RP2D) identified in Part 1.
  • Drug: itacitinib
    itacitinb Immediate Release (IR) will be dosed orally twice a day
    Other names:
    • INCB039110

More Details

Active, not recruiting
Incyte Corporation

Study Contact


Study information shown on this site is derived from ClinicalTrials.gov (a public registry operated by the National Institutes of Health). The listing of studies provided is not certain to be all studies for which you might be eligible. Furthermore, study eligibility requirements can be difficult to understand and may change over time, so it is wise to speak with your medical care provider and individual research study teams when making decisions related to participation.