for people ages 18 years and up (full criteria)
at La Jolla, California and other locations
study started
estimated completion



This study evaluates KRT-232, a novel oral small molecule inhibitor of MDM2, for the treatment of patients with myelofibrosis (MF) who no longer benefit from treatment with a JAK inhibitor. Inhibition of MDM2 is a novel mechanism of action in MF. This study will be conducted in 2 phases. Phase 2 will determine the KRT-232 recommended dose and dosing schedule; Phase 3 will test KRT-232 vs Best Available Therapy (BAT). Patients in the Phase 3 part of the study will be randomized 2:1 to receive either KRT-232 (Arm 1) or BAT (Arm 2). The BAT administered will be determined by the treating physician, with the option to "cross-over" to KRT-232 treatment after 6 months of BAT or if the disease worsens at any time.

Official Title

A Phase 2/3 Randomized, Controlled, Open-Label Study of KRT 232 in Subjects With Primary Myelofibrosis (PMF), Post Polycythemia Vera MF (Post-PV-MF), Or Post Essential Thrombocythemia MF (Post-ET-MF) Who Are Relapsed or Refractory to Janus Kinase (JAK) Inhibitor Treatment


Primary Myelofibrosis (PMF) Post-Polycythemia Vera MF (Post-PV-MF) Post-Essential Thrombocythemia MF (Post-ET-MF) navtemadlin Polycythemia Vera Primary Myelofibrosis Polycythemia Thrombocytosis Thrombocythemia, Essential KRT-232 Best Available Therapy (BAT)


You can join if…

Open to people ages 18 years and up

  • Confirmed diagnosis of PMF, post-PV MF or post-ET MF (WHO)
  • High, intermediate-2, or intermediate-1 risk Dynamic International Prognostic System (DIPSS)
  • Failure of prior treatment with JAK inhibitor
  • ECOG ≤ 2

You CAN'T join if...

  • Prior splenectomy
  • Splenic irradiation within 3 months prior to randomization
  • History of major hemorrhage or intracranial hemorrhage within 6 months prior to randomization
  • History of stroke, reversible ischemic neurological defect or transient ischemic attack within 6 months prior to randomizatio
  • Prior MDM2 inhibitor therapy or p53-directed therapy
  • Prior allogeneic stem-cell transplant or plans for allogeneic stem cell transplant
  • History of major organ transplant
  • Grade 2 or higher QTc prolongation (> 480 milliseconds per NCI-CTCAE criteria, version 5.0)


  • University of California San Diego Moores Cancer Center accepting new patients
    La Jolla California 92093 United States
  • Innovative Clinical Research Institute accepting new patients
    Whittier California 90603 United States


accepting new patients
Start Date
Completion Date
Kartos Therapeutics, Inc.
Phase 2/3
Study Type
Last Updated