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 JAK inhibitor. Inhibition of MDM2 is a novel mechanism of action in MF. This study is a global, open-label Phase 2 study to determine the efficacy and safety of KRT-232 in patients with primary MF, post-polycythemia vera MF, or post-essential thrombocythemia MF who have failed previous treatment with JAK inhibitor (Part A), or Ruxolitinib (Part B). In Part A of the study, patients will be randomly assigned to 2 different doses and 3 different dosing schedules of KRT-232. In Part B of the study, patients will be treated at the recommended dose and schedule from Part A.

Official Title

An Open-Label, Phase 2a/2b 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 Have Failed a JAK Inhibitor


Primary Myelofibrosis (PMF) Post-Polycythemia Vera MF (Post-PV-MF) Post-Essential Thrombocythemia MF (Post-ET-MF) Polycythemia Vera Primary Myelofibrosis Polycythemia Thrombocytosis Thrombocythemia, Essential KRT-232


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 (Part A) or ruxolitinib (Part B)
  • ECOG ≤ 2

You CAN'T join if...

  • Prior splenectomy
  • Splenic irradiation within 3 months prior to the first dose of KRT-232
  • Active or chronic bleeding within 4 weeks prior to the first dose of KRT-232
  • Prior MDM2 inhibitor therapy or p53-directed therapy
  • Prior treatment with HDAC or BCL-2 inhibitors
  • 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
Study Type
Last Updated