In September 2023, the study was terminated because of a Sponsor decision, unrelated to safety concerns.

This study evaluates KRT-232, a novel oral small molecule inhibitor of MDM2, when administered alone and in combination with low-dose cytarabine (LDAC) or Decitabine for the treatment of adults with Acute Myeloid Leukemia (AML) and AML secondary to myeloproliferative neoplasms (MPN). Participants must be relapsed/refractory (having failed prior therapy) and will be assigned to receive monotherapy (KRT-232 alone) or combination therapy (KRT-232 with LDAC or KRT-232 with Decitabine).

Key Inclusion Criteria:

• Part A: Patients with relapsed or refractory AML, or newly-diagnosed AML secondary to MPN
• Part B:Patients with relapsed or refractory AML secondary to MPN (myelofibrosis [MF], polycythemia vera [PV], or essential thrombocythemia [ET]); patients may have been treated with ≥1 prior lines of therapy for their AML secondary to MPN.
• Adequate hepatic and renal function
• Appropriate prior treatment with an FLT3 or IDH1/2 inhibitor where applicable

Key Exclusion Criteria:

• Patients who are TP53 mutation positive
• Prior treatment with an MDM2 antagonist therapy
• Patients treated with ≥ 18 g/m2 of cytarabine within the prior 90 days are not eligible to be treated with cytarabine on this study but may be treated with decitabine (for Part A) .
• Patients previously treated with decitabine are not eligible to receive decitabine on this study but may be treated with cytarabine (for Part A) .
• Patients who have received an allogeneic HSCT within 90 days of enrollment or who have active graft-versus-host disease requiring active therapy (for Part A)
• Allogeneic stem cell transplant within 3 months; autologous stem cell transplant within 3 months or active graft-versus-host disease prior to first dose of study treatment (for Part B)
• Patients who have received immunosuppressive therapy for graft-versus-host disease within 1 month prior to enrollment into this study
• Patients who are eligible for an allogeneic HSCT per the opinion of the investigator and have a donor. Patients who are HSCT-eligible in the opinion of the investigator, but who refuse a transplant, are eligible for the study.
• Patients with known CNS involvement with AML, acute promyelocytic leukemia (APL), or a history of bleeding diathesis
• Patients who have had major surgery within 28 days prior to the first treatment with KRT-232
• Women who are pregnant or breastfeeding