KRT-232 Versus Best Available Therapy for the Treatment of Subjects With Myelofibrosis Who Are Relapsed or Refractory to JAK Inhibitor Treatment

Purpose

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.

Conditions

  • Primary Myelofibrosis (PMF)
  • Post-Polycythemia Vera MF (Post-PV-MF)
  • Post-Essential Thrombocythemia MF (Post-ET-MF)

Eligibility

Eligible Ages
Over 18 Years
Eligible Genders
All
Accepts Healthy Volunteers
No

Inclusion Criteria

  • 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

Exclusion Criteria

  • 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 randomization - 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)

Study Design

Phase
Phase 2/Phase 3
Study Type
Interventional
Allocation
Randomized
Intervention Model
Crossover Assignment
Primary Purpose
Treatment
Masking
Single (Outcomes Assessor)

Arm Groups

ArmDescriptionAssigned Intervention
Experimental
Part A Cohort 1
KRT-232 120 mg by mouth once daily for Days 1-7, off treatment for Days 8-21 (21-day cycles)
  • Drug: KRT-232
    KRT-232, administered by mouth
Experimental
Part A Cohort 2
KRT-232 240 mg by mouth once daily for Days 1-7, off treatment for Days 8-21 (21-day cycles)
  • Drug: KRT-232
    KRT-232, administered by mouth
Experimental
Part A Cohort 3
KRT-232 240 mg by mouth once daily for Days 1-7, off treatment for Days 8-28 (28-day cycles)
  • Drug: KRT-232
    KRT-232, administered by mouth
Experimental
Part A Cohort 4b
KRT-232 240 mg by mouth once daily for Days 1-5, off treatment for Days 6-28 (28-day cycles)
  • Drug: KRT-232
    KRT-232, administered by mouth
Experimental
Part B Arm 1 KRT-232
KRT-232 240 mg by mouth once daily for Days 1-7, off treatment for Days 8-28 (28-day cycles)
  • Drug: KRT-232
    KRT-232, administered by mouth
Active Comparator
Part B Arm 2 Best Available Therapy
Best available therapy at the discretion of the investigator, on a 28-day cycle.
  • Drug: Best Available Therapy (BAT)
    Best available therapy options include: hydroxyurea chemotherapy or supportive care (including but not limited to corticosteroids and androgens; JAK inhibitors not allowed).

Recruiting Locations

More Details

Status
Recruiting
Sponsor
Kartos Therapeutics, Inc.

Study Contact

John Mei
650-542-0136
jmei@kartosthera.com