A Study to Compare Standard Chemotherapy to Therapy With CPX-351 and/or Gilteritinib for Patients With Newly Diagnosed AML With or Without FLT3 Mutations

PRIMARY OBJECTIVE:

1. To compare event-free survival (EFS) in children with de novo acute myeloid leukemia (AML) without FLT3 mutations who are randomly assigned to standard induction therapy on Arm A with daunorubicin, cytarabine (DA) and gemtuzumab ozogamicin (GO) (DA-GO) versus Arm B with CPX-351 and GO.

SECONDARY OBJECTIVES:

1. To compare overall survival (OS) and rates of end of Induction 1 (EOI1) minimal residual disease (MRD) in children with de novo AML without FLT3 mutations who are randomly assigned to standard induction therapy (Arm A) with DA-GO versus CPX-351 and GO (Arm B).

II. To estimate the EFS and rate of EOI1 MRD in FLT3 internal tandem duplication mutation positive patients (FLT3/ITD+; as defined by allelic ratio > 0.1) without favorable cytomolecular characteristics (NPM1 and/or CEBPA) receiving gilteritinib fumarate (gilteritinib) in combination with DA-GO (Arm AC).

III. To estimate the EFS and rate of EOI1 MRD in patients with non-ITD FLT3 activating mutations who receive backbone therapy (DA-GO or CPX-351 and GO) with gilteritinib (Arms AD and BD).

IV. To determine the feasibility of combining gilteritinib and DA-GO or CPX-351 and GO in patients with FLT3/ITD and FLT3/TKD mutations (Arm AC/Arm BC/Arm AD/Arm BD).

1. To compare EOI1 MRD and EFS in patients with FLT3/ITD AML+ (allelic ratio [AR] > 0.1) without favorable cytogenetic/molecular characteristics treated with DA-GO-gilteritinib versus (vs) CPX-GO-gilteritinib (Arm AC vs Arm BC).

VI. To compare the incidence of significant left ventricular systolic dysfunction (LVSD) in children with de novo AML without FLT3 mutations who are randomly assigned to standard induction therapy (Arm A) with DA-GO versus CPX-351 and GO (Arm B).

VII. To compare the changes in echocardiography-derived measures of cardiac function, including left ventricular ejection fraction (EF) and global longitudinal strain (GLS), throughout AML therapy in patients with low and high risk AML without FLT3 mutations receiving Arm A vs Arm B.

VIII. Determine if early changes in sensitive echocardiographic measures of cardiac function (i.e., post-Induction 1 decline in GLS) and elevations in circulating cardiac biomarkers (i.e., cardiac troponin T and N-terminal pro b-type natriuretic peptide) are associated with subsequent declines in left ventricular ejection fraction in patients with non-FLT3 mutant AML receiving therapy on Arms A or B.

IX. To compare longitudinal acute changes in neuropsychological functioning and neurocognitive late effects between those with central nervous system (CNS) disease and those without CNS disease and between those treated with hematopoietic stem cell transplant (HSCT) and those treated with chemotherapy only for patients on Arms A and B.

1. To compare cardiotoxicity measures (EF, GLS, and cardiac biomarkers) in patients receiving standard induction with dexrazoxane hydrochloride (dexrazoxane) vs. CPX-351 in the context of gilteritinib therapy and explore whether the differential cardiotoxicity across arms varies from that observed in non-FLT3 mutant AML without gilteritinib exposure.

EXPLORATORY OBJECTIVES:

1. To estimate the EFS and rate of EOI1 MRD in patients with high allelic ratio (HAR) FLT3/ITD+ patients, as historically defined by an AR > 0.4, receiving gilteritinib in combination with DA-GO (Arm AC with AR > 0.4).

II. To estimate the EFS, OS, and rate of EOI1 MRD in FLT3/ITD+ patients (as defined by allelic ratio > 0.1) with NPM1 and/or bZIP CEBPA mutations receiving gilteritinib in combination with DA-GO (Arm AC).

III. Compare the changes in high sensitivity troponin and natriuretic peptide elevations throughout AML therapy, as measured at the end of each chemotherapy course, in patients with low and high risk AML without FLT3 mutations receiving Arm A vs Arm B.

IV. Quantify the association of host factors (age, sex, body mass index [BMI], race), treatment exposures (cumulative anthracycline dose, anthracycline arm, hematopoietic stem cell transplant vs. chemotherapy alone), early declines in GLS, and elevations in cardiac biomarkers (cTnT and NT-proBNP) with subsequent LVSD.

1. To describe the rates of CNS disease utilizing an updated strategy for diagnosing and defining CNS disease in pediatric AML.

VI. To describe the rates of CNS relapse (both isolated CNS and combined bone marrow/CNS) when utilizing this updated strategy as well as changing CNS prophylaxis and treatment to include triple intrathecal chemotherapy.

VII. To describe the rate of bone marrow measurable residual disease, detected by multi-dimensional flow cytometry, prior to hematopoietic stem cell transplant (HSCT).

VIII. To describe plasma metabolomics that may impact efficacy, toxicity, and/or pharmacokinetics of allogeneic HSCT.

IX. To estimate the prevalence of non-risk stratifying cytogenetic/molecular variants and assess their impact on outcome in childhood AML.

1. To describe the pharmacokinetic parameters of plasma cytarabine and daunorubicin after CPX-351 administration to pediatric and young adult patients with new diagnosis of AML.

XI. To describe the pharmacokinetic parameters of orally administered gilteritinib when administered to pediatric and young adult patients with new diagnosis of AML.

XII. To describe the pharmacodynamic parameters of gilteritinib using the FLT3 plasma inhibitory activity assay (PIA) when administered to children and young adults with new diagnosis of AML and FLT3 mutations.

XIII. To estimate OS in patients with FLT3/ITD+ AML (AR > 0.1) without favorable cytogenetic/molecular characteristics treated with DA-GO-gilteritinib or CPX-351-GO-gilteritinib (Separate analyses will be conducted for Arm AC vs Arm BC).

XIV. To compare results of molecular MRD, including RT-qPCR and digital droplet PCR, with centralized flow MRD in KMT2A and NUP98 rearranged pediatric AML patients at the end of Induction 1 and end of Induction 2.

1. Evaluate the utility of molecular MRD following EOI2 to serve as a prognostic biomarker in KMT2A rearranged AML by comparing disease free survival (DFS) and OS for patients according to their molecular MRD status at the end of Induction 2.

OUTLINE: Patients are randomized to either Arm A or B and assigned to Arm C or D based on FLT3 testing results. As of 11/19/24 arms B, BC and BD are closed and new patients receive treatment in Arm A Low Risk Group 2 Induction 1 or Arm A High Risk Induction 1, and then assigned to arm AC or AD per FLT3 results.

Risk group assignments are calculated based on cytogenetic, molecular and genomic findings (details in protocol)

1. Low Risk 1
2. Low Risk 2
3. High Risk TREATMENT FOR PATIENTS WITHOUT FLT3 MUTATIONS: ARM A LOW RISK GROUP 1: INDUCTION 1: Patients receive cytarabine intravenously (IV) over 1-30 minutes every 12 hours (Q12H) on days 1-10, dexrazoxane IV over 15 minutes and daunorubicin IV over 1-15 minutes on days 1, 3, and 5, and gemtuzumab ozogamicin IV over 2 hours on day 6. Patients with CNS1 receive methotrexate intrathecally (IT), therapeutic hydrocortisone (hydrocortisone) IT, and cytarabine IT on day 8. Patients with CNS2, CNS3a, and CNS3b receive methotrexate IT, hydrocortisone IT, and cytarabine IT once weekly (QW) starting on day 8 for 4-6 weeks (may continue into Induction 2) until the cerebral spinal fluid (CSF) is clear of blasts (CNS1 status). Patients with CNS3c receive methotrexate IT, hydrocortisone IT, and cytarabine IT QW starting on day 1 for 6 weeks (may continue into Induction 2). INDUCTION 2: Patients with CNS1 receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 0. Patients with CNS2 receive methotrexate IT, hydrocortisone IT, and cytarabine IT QW starting on day 0 until CNS1 status is reached. Patients also receive cytarabine IV over 1-30 minutes Q12H on days 1-8 and dexrazoxane IV over 15 minutes and daunorubicin IV over 1-15 minutes on days 1, 3, and 5. INTENSIFICATION 1: Patients receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 0. Patients also receive high-dose cytarabine IV over 1-3 hours Q12H and etoposide IV over 90-120 minutes on days 1-5. INTENSIFICATION 2: Patients receive high-dose cytarabine IV over 3 hours Q12H on days 1, 2, 8, and 9. Patients also receive asparaginase Erwinia chrysanthemi intramuscularly (IM) on days 2 and 9 or IV over 1-2 hours on days 2 and 9. ARM B LOW RISK GROUP 1: INDUCTION 1: Patients receive CPX-351 IV over 90 minutes on days 1, 3, and 5, and gemtuzumab ozogamicin IV over 2 hours on day 6. Patients with CNS1 receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 8. Patients with CNS2, CNS3a, and CNS3b receive methotrexate IT, hydrocortisone IT, and cytarabine IT QW starting on day 8 for 4-6 weeks (may continue into Induction 2) until the CSF is clear of blasts (CNS1 status). Patients with CNS3c receive methotrexate IT, hydrocortisone IT, and cytarabine IT QW starting on day 1 for 6 weeks (may continue into Induction 2). INDUCTION 2: Patients with CNS1 receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 0. Patients with CNS2 receive methotrexate IT, hydrocortisone IT, and cytarabine IT QW starting on day 0 until CNS1 status is reached. Patients also receive CPX-351 IV over 90 minutes on days 1, 3, and 5. INTENSIFICATION 1: Patients receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 0. Patients also receive high-dose cytarabine IV over 1-3 hours Q12H and etoposide IV over 90-120 minutes on days 1-5. INTENSIFICATION 2: Patients receive high-dose cytarabine IV over 3 hours Q12H on days 1, 2, 8, and 9. Patients also receive asparaginase Erwinia chrysanthemi IM on days 2 and 9 or IV over 1-2 hours on days 2 and 9. ARM A LOW RISK GROUP 2: INDUCTION 1: Patients receive cytarabine IV over 1-30 minutes Q12H on days 1-10, dexrazoxane IV over 15 minutes and daunorubicin IV over 1-15 minutes on days 1, 3, and 5, and gemtuzumab ozogamicin IV over 2 hours on day 6. Patients with CNS1 receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 8. Patients with CNS2, CNS3a, and CNS3b receive methotrexate IT, hydrocortisone IT, and cytarabine IT QW starting on day 8 for 4-6 weeks (may continue into Induction 2) until the CSF is clear of blasts (CNS1 status). Patients with CNS3c receive methotrexate IT, hydrocortisone IT, and cytarabine IT QW starting on day 1 for 6 weeks (may continue into Induction 2). INDUCTION 2: Patients with CNS1 receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 0. Patients with CNS2 receive methotrexate IT, hydrocortisone IT, and cytarabine IT QW starting on day 0 until CNS1 status is reached. Patients also receive cytarabine IV over 1-30 minutes Q12H on days 1-8 and dexrazoxane IV over 15 minutes and daunorubicin IV over 1-15 minutes on days 1, 3, and 5. INTENSIFICATION 1: Patients receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 0. Patients also receive high-dose cytarabine IV over 1-3 hours Q12H and etoposide IV over 90-120 minutes on days 1-5. INTENSIFICATION 2: Patients receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 0. Patients also receive high-dose cytarabine IV over 1-3 hours Q12H on days 1-4 and dexrazoxane IV over 15 minutes and mitoxantrone hydrochloride (mitoxantrone) IV over 5-15 minutes on days 3-6. INTENSIFICATION 3: Patients receive high-dose cytarabine IV over 3 hours Q12H on days 1, 2, 8, and 9. Patients also receive asparaginase Erwinia chrysanthemi IM on days 2 and 9 or IV over 1-2 hours on days 2 and 9. ARM B LOW RISK GROUP 2: INDUCTION 1: Patients receive CPX-351 IV over 90 minutes on days 1, 3, and 5, and gemtuzumab ozogamicin IV over 2 hours on day 6. Patients with CNS1 receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 8. Patients with CNS2, CNS3a, and CNS3b receive methotrexate IT, hydrocortisone IT, and cytarabine IT QW starting on day 8 for 4-6 weeks (may continue into Induction 2) until the CSF is clear of blasts (CNS1 status). Patients with CNS3c receive methotrexate IT, hydrocortisone IT, and cytarabine IT QW starting on day 1 for 6 weeks (may continue into Induction 2). INDUCTION 2: Patients with CNS1 receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 0. Patients with CNS2 receive methotrexate IT, hydrocortisone IT, and cytarabine IT QW starting on day 0 until CNS1 status is reached. Patients also receive CPX-351 IV over 90 minutes on days 1, 3, and 5. INTENSIFICATION 1: Patients receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 0. Patients also receive high-dose cytarabine IV over 1-3 hours Q12H and etoposide IV over 90-120 minutes on days 1-5. INTENSIFICATION 2: Patients receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 0. Patients also receive high-dose cytarabine IV over 1-3 hours Q12H on days 1-4 and dexrazoxane IV over 15 minutes and mitoxantrone hydrochloride (mitoxantrone) IV over 5-15 minutes on days 3-6. INTENSIFICATION 3: Patients receive high-dose cytarabine IV over 3 hours Q12H on days 1, 2, 8, and 9. Patients also receive asparaginase Erwinia chrysanthemi IM on days 2 and 9 or IV over 1-2 hours on days 2 and 9. ARM A HIGH RISK GROUP: INDUCTION 1: Patients receive cytarabine IV over 1-30 minutes Q12H on days 1-10, dexrazoxane IV over 15 minutes and daunorubicin IV over 1-15 minutes on days 1, 3, and 5, and gemtuzumab ozogamicin IV over 2 hours on day 6. Patients with CNS1 receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 8. Patients with CNS2, CNS3a, and CNS3b receive methotrexate IT, hydrocortisone IT, and cytarabine IT QW starting on day 8 for 4-6 weeks (may continue into Induction 2) until the CSF is clear of blasts (CNS1 status). Patients with CNS3c receive methotrexate IT, hydrocortisone IT, and cytarabine IT QW starting on day 1 for 6 weeks (may continue into Induction 2). INDUCTION 2: Patients with CNS1 receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 0. Patients with CNS2 receive methotrexate IT, hydrocortisone IT, and cytarabine IT QW starting on day 0 until CNS1 status is reached. Patients also receive cytarabine IV over 1-30 minutes Q12H on days 1-8 and dexrazoxane IV over 15 minutes and daunorubicin IV over 1-15 minutes on days 1, 3, and 5. INTENSIFICATION 1: Patients receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 0. Patients also receive high-dose cytarabine IV over 1-3 hours Q12H and etoposide IV over 90-120 minutes on days 1-5. HSCT: After completion of Intensification 1 and investigator assigned conditioning regimen, patients undergo allogeneic HSCT. ARM B HIGH RISK GROUP: INDUCTION 1: Patients receive CPX-351 IV over 90 minutes on days 1, 3, and 5, and gemtuzumab ozogamicin IV over 2 hours on day 6. Patients with CNS1 receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 8. Patients with CNS2, CNS3a, and CNS3b receive methotrexate IT, hydrocortisone IT, and cytarabine IT QW starting on day 8 for 4-6 weeks (may continue into Induction 2) until the CSF is clear of blasts (CNS1 status). Patients with CNS3c receive methotrexate IT, hydrocortisone IT, and cytarabine IT QW starting on day 1 for 6 weeks (may continue into Induction 2). INDUCTION 2: Patients with CNS1 receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 0. Patients with CNS2 receive methotrexate IT, hydrocortisone IT, and cytarabine IT QW starting on day 0 until CNS1 status is reached. Patients also receive CPX-351 IV over 90 minutes on days 1, 3, and 5. INTENSIFICATION 1: Patients receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 0. Patients also receive high-dose cytarabine IV over 1-3 hours Q12H and etoposide IV over 90-120 minutes on days 1-5. HSCT: After completion of Intensification 1 and investigator assigned conditioning regimen, patients undergo allogeneic HSCT. TREATMENT FOR PATIENTS WITH FLT3/ITD MUTATIONS (ITD AR > 0.1): ARM AC LOW RISK GROUP 2: CONTINUED INDUCTION 1 (WITH GILTERITINIB): Patients receive cytarabine IV over 1-30 minutes Q12H on days 1-10, dexrazoxane IV over 15 minutes and daunorubicin IV over 1-15 minutes on days 1, 3, and 5, gemtuzumab ozogamicin IV over 2 hours on day 6, and gilteritinib orally (PO)/nasogastric (NG)/gastrostomy (G)-tube once daily (QD) on days 11-31. Patients with CNS1 receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 8. Patients with CNS2, CNS3a, and CNS3b receive methotrexate IT, hydrocortisone IT, and cytarabine IT QW starting on day 8 for 4-6 weeks (may continue into Induction 2) until the CSF is clear of blasts (CNS1 status). Patients with CNS3c receive methotrexate IT, hydrocortisone IT, and cytarabine IT QW starting on day 1 for 6 weeks (may continue into Induction 2). INDUCTION 2 (WITH GILTERITINIB): Patients with CNS1 receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 0. Patients with CNS2 receive methotrexate IT, hydrocortisone IT, and cytarabine IT QW starting on day 0 until CNS1 status is reached. Patients also receive cytarabine IV over 1-30 minutes Q12H on days 1-8, dexrazoxane IV over 15 minutes and daunorubicin IV over 1-15 minutes on days 1, 3, and 5, and gilteritinib PO/NG/G-tube QD on days 11-31. INTENSIFICATION 1 (WITH GILTERITINIB): Patients receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 0. Patients also receive high-dose cytarabine IV over 1-3 hours Q12H and etoposide IV over 90-120 minutes on days 1-5, and gilteritinib PO/NG/G-tube QD on days 6-26. INTENSIFICATION 2 (WITH GILTERITINIB): Patients receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 0. Patients also receive high-dose cytarabine IV over 1-3 hours Q12H on days 1-4, dexrazoxane IV over 15 minutes and mitoxantrone IV over 5-15 minutes on days 3-6, and gilteritinib PO/NG/G-tube QD on days 7-27. INTENSIFICATION 3 (WITH GILTERITINIB): Patients receive high-dose cytarabine IV over 3 hours Q12H on days 1, 2, 8, and 9, asparaginase Erwinia chrysanthemi IM or IV over 1-2 hours, and gilteritinib PO/NG/G-tube QD on days 10-30. POST-CHEMOTHERAPY GILTERITINIB MAINTENANCE: Patients receive gilteritinib PO/NG/G-tube QD on days 1-365. ARM BC LOW RISK GROUP 2: CONTINUED INDUCTION 1 (WITH GILTERITINIB): Patients receive CPX-351 IV over 90 minutes on days 1, 3, and 5, gemtuzumab ozogamicin IV over 2 hours on day 6, and gilteritinib PO/NG/G-tube QD on days 11-31. Patients with CNS1 receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 8. Patients with CNS2, CNS3a, and CNS3b receive methotrexate IT, hydrocortisone IT, and cytarabine IT QW starting on day 8 for 4-6 weeks (may continue into Induction 2) until the CSF is clear of blasts (CNS1 status). Patients with CNS3c receive methotrexate IT, hydrocortisone IT, and cytarabine IT QW starting on day 1 for 6 weeks (may continue into Induction 2). INDUCTION 2 (WITH GILTERITINIB): Patients with CNS1 receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 0. Patients with CNS2 receive methotrexate IT, hydrocortisone IT, and cytarabine IT QW starting on day 0 until CNS1 status is reached. Patients also receive CPX-351 IV over 90 minutes on days 1, 3, and 5 and gilteritinib PO/NG/G-tube QD on days 11-31. INTENSIFICATION 1 (WITH GILTERITINIB): Patients receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 0. Patients also receive high-dose cytarabine IV over 1-3 hours Q12H and etoposide IV over 90-120 minutes on days 1-5, and gilteritinib PO/NG/G-tube QD on days 6-26. INTENSIFICATION 2 (WITH GILTERITINIB): Patients receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 0. Patients also receive high-dose cytarabine IV over 1-3 hours Q12H on days 1-4, dexrazoxane IV over 15 minutes and mitoxantrone IV over 5-15 minutes on days 3-6, and gilteritinib PO/NG/G-tube QD on days 7-27. INTENSIFICATION 3 (WITH GILTERITINIB): Patients receive high-dose cytarabine IV over 3 hours Q12H on days 1, 2, 8, and 9, asparaginase Erwinia chrysanthemi IM or IV over 1-2 hours, and gilteritinib PO/NG/G-tube QD on days 10-30. POST-CHEMOTHERAPY GILTERITINIB MAINTENANCE: Patients receive gilteritinib PO/NG/G-tube QD on days 1-365. ARM AC HIGH RISK GROUP: CONTINUED INDUCTION 1 (WITH GILTERITINIB): Patients receive cytarabine IV over 1-30 minutes Q12H on days 1-10, dexrazoxane IV over 15 minutes and daunorubicin IV over 1-15 minutes on days 1, 3, and 5, gemtuzumab ozogamicin IV over 2 hours on day 6, and gilteritinib PO/NG/G-tube QD on days 11-31. Patients with CNS1 receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 8. Patients with CNS2, CNS3a, and CNS3b receive methotrexate IT, hydrocortisone IT, and cytarabine IT QW starting on day 8 for 4-6 weeks (may continue into Induction 2) until the CSF is clear of blasts (CNS1 status). Patients with CNS3c receive methotrexate IT, hydrocortisone IT, and cytarabine IT QW starting on day 1 for 6 weeks (may continue into Induction 2). INDUCTION 2 (WITH GILTERITINIB): Patients with CNS1 receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 0. Patients with CNS2 receive methotrexate IT, hydrocortisone IT, and cytarabine IT QW starting on day 0 until CNS1 status is reached. Patients also receive cytarabine IV over 1-30 minutes Q12H on days 1-8, dexrazoxane IV over 15 minutes and daunorubicin IV over 1-15 minutes on days 1, 3, and 5, and gilteritinib PO/NG/G-tube QD on days 11-31. INTENSIFICATION 1 (WITH GILTERITINIB): Patients receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 0. Patients also receive high-dose cytarabine IV over 1-3 hours Q12H and etoposide IV over 90-120 minutes on days 1-5, and gilteritinib PO/NG/G-tube QD on days 6-26. HSCT: After completion of Intensification 1 and investigator assigned conditioning regimen, patients undergo allogeneic HSCT. POST-HSCT GILTERITINIB MAINTENANCE: Beginning 30-120 days after completion of HSCT, patients receive gilteritinib PO/NG/G-tube QD on days 1-365. ARM BC HIGH RISK GROUP: CONTINUED INDUCTION 1 (WITH GILTERITINIB): Patients receive CPX-351 IV over 90 minutes on days 1, 3, and 5, gemtuzumab ozogamicin IV over 2 hours on day 6, and gilteritinib PO/NG/G-tube QD on days 11-31. Patients with CNS1 receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 8. Patients with CNS2, CNS3a, and CNS3b receive methotrexate IT, hydrocortisone IT, and cytarabine IT QW starting on day 8 for 4-6 weeks (may continue into Induction 2) until the CSF is clear of blasts (CNS1 status). Patients with CNS3c receive methotrexate IT, hydrocortisone IT, and cytarabine IT QW starting on day 1 for 6 weeks (may continue into Induction 2). INDUCTION 2 (WITH GILTERITINIB): Patients with CNS1 receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 0. Patients with CNS2 receive methotrexate IT, hydrocortisone IT, and cytarabine IT QW starting on day 0 until CNS1 status is reached. Patients also receive CPX-351 IV over 90 minutes on days 1, 3, and 5 and gilteritinib PO/NG/G-tube QD on days 11-31. INTENSIFICATION 1 (WITH GILTERITINIB): Patients receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 0. Patients also receive high-dose cytarabine IV over 1-3 hours Q12H and etoposide IV over 90-120 minutes on days 1-5, and gilteritinib PO/NG/G-tube QD on days 6-26. HSCT: After completion of Intensification 1 and investigator assigned conditioning regimen, patients undergo allogeneic HSCT. POST-HSCT GILTERITINIB MAINTENANCE: Beginning 30-120 days after completion of HSCT, patients receive gilteritinib PO/NG/G-tube QD on days 1-365. TREATMENT FOR NON-ITD FLT3 ACTIVATING MUTATIONS: ARM AD LOW RISK GROUP 2: CONTINUED INDUCTION 1 (WITH GILTERITINIB): Patients receive cytarabine IV over 1-30 minutes Q12H on days 1-10, dexrazoxane IV over 15 minutes and daunorubicin IV over 1-15 minutes on days 1, 3, and 5, gemtuzumab ozogamicin IV over 2 hours on day 6, and gilteritinib PO/NG/G-tube QD on days 11-31. Patients with CNS1 receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 8. Patients with CNS2, CNS3a, and CNS3b receive methotrexate IT, hydrocortisone IT, and cytarabine IT QW starting on day 8 for 4-6 weeks (may continue into Induction 2) until the CSF is clear of blasts (CNS1 status). Patients with CNS3c receive methotrexate IT, hydrocortisone IT, and cytarabine IT QW starting on day 1 for 6 weeks (may continue into Induction 2). INDUCTION 2 (WITH GILTERITINIB): Patients with CNS1 receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 0. Patients with CNS2 receive methotrexate IT, hydrocortisone IT, and cytarabine IT QW starting on day 0 until CNS1 status is reached. Patients also receive cytarabine IV over 1-30 minutes Q12H on days 1-8, dexrazoxane IV over 15 minutes and daunorubicin IV over 1-15 minutes on days 1, 3, and 5, and gilteritinib PO/NG/G-tube QD on days 11-31. INTENSIFICATION 1 (WITH GILTERITINIB): Patients receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 0. Patients also receive high-dose cytarabine IV over 1-3 hours Q12H and etoposide IV over 90-120 minutes on days 1-5, and gilteritinib PO/NG/G-tube QD on days 6-26. INTENSIFICATION 2 (WITH GILTERITINIB): Patients receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 0. Patients also receive high-dose cytarabine IV over 1-3 hours Q12H on days 1-4, dexrazoxane IV over 15 minutes and mitoxantrone IV over 5-15 minutes on days 3-6, and gilteritinib PO/NG/G-tube QD on days 7-27. INTENSIFICATION 3 (WITH GILTERITINIB): Patients receive high-dose cytarabine IV over 3 hours Q12H on days 1, 2, 8, and 9, asparaginase Erwinia chrysanthemi IM or IV over 1-2 hours, and gilteritinib PO/NG/G-tube QD on days 10-30. POST-CHEMOTHERAPY GILTERITINIB MAINTENANCE: Patients receive gilteritinib PO/NG/G-tube QD on days 1-365. ARM BD LOW RISK GROUP 2: CONTINUED INDUCTION 1 (WITH GILTERITINIB): Patients receive CPX-351 IV over 90 minutes on days 1, 3, and 5, gemtuzumab ozogamicin IV over 2 hours on day 6, and gilteritinib PO/NG/G-tube QD on days 11-31. Patients with CNS1 receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 8. Patients with CNS2, CNS3a, and CNS3b receive methotrexate IT, hydrocortisone IT, and cytarabine IT QW starting on day 8 for 4-6 weeks (may continue into Induction 2) until the CSF is clear of blasts (CNS1 status). Patients with CNS3c receive methotrexate IT, hydrocortisone IT, and cytarabine IT QW starting on day 1 for 6 weeks (may continue into Induction 2). INDUCTION 2 (WITH GILTERITINIB): Patients with CNS1 receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 0. Patients with CNS2 receive methotrexate IT, hydrocortisone IT, and cytarabine IT QW starting on day 0 until CNS1 status is reached. Patients also receive CPX-351 IV over 90 minutes on days 1, 3, and 5 and gilteritinib PO/NG/G-tube QD on days 11-31. INTENSIFICATION 1 (WITH GILTERITINIB): Patients receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 0. Patients also receive high-dose cytarabine IV over 1-3 hours Q12H and etoposide IV over 90-120 minutes on days 1-5, and gilteritinib PO/NG/G-tube QD on days 6-26. INTENSIFICATION 2 (WITH GILTERITINIB): Patients receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 0. Patients also receive high-dose cytarabine IV over 1-3 hours Q12H on days 1-4, dexrazoxane IV over 15 minutes and mitoxantrone IV over 5-15 minutes on days 3-6, and gilteritinib PO/NG/G-tube QD on days 7-27. INTENSIFICATION 3 (WITH GILTERITINIB): Patients receive high-dose cytarabine IV over 3 hours Q12H on days 1, 2, 8, and 9, asparaginase Erwinia chrysanthemi IM or IV over 1-2 hours, and gilteritinib PO/NG/G-tube QD on days 10-30. POST-CHEMOTHERAPY GILTERITINIB MAINTENANCE: Patients receive gilteritinib PO/NG/G-tube QD on days 1-365. ARM AD HIGH RISK GROUP: CONTINUED INDUCTION 1 (WITH GILTERITINIB): Patients receive cytarabine IV over 1-30 minutes Q12H on days 1-10, dexrazoxane IV over 15 minutes and daunorubicin IV over 1-15 minutes on days 1, 3, and 5, gemtuzumab ozogamicin IV over 2 hours on day 6, and gilteritinib PO/NG/G-tube QD on days 11-31. Patients with CNS1 receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 8. Patients with CNS2, CNS3a, and CNS3b receive methotrexate IT, hydrocortisone IT, and cytarabine IT QW starting on day 8 for 4-6 weeks (may continue into Induction 2) until the CSF is clear of blasts (CNS1 status). Patients with CNS3c receive methotrexate IT, hydrocortisone IT, and cytarabine IT QW starting on day 1 for 6 weeks (may continue into Induction 2). INDUCTION 2 (WITH GILTERITINIB): Patients with CNS1 receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 0. Patients with CNS2 receive methotrexate IT, hydrocortisone IT, and cytarabine IT QW starting on day 0 until CNS1 status is reached. Patients also receive cytarabine IV over 1-30 minutes Q12H on days 1-8, dexrazoxane IV over 15 minutes and daunorubicin IV over 1-15 minutes on days 1, 3, and 5, and gilteritinib PO/NG/G-tube QD on days 11-31. INTENSIFICATION 1 (WITH GILTERITINIB): Patients receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 0. Patients also receive high-dose cytarabine IV over 1-3 hours Q12H and etoposide IV over 90-120 minutes on days 1-5, and gilteritinib PO QD on days 6-26. HSCT: After completion of Intensification 1 and investigator assigned conditioning regimen, patients undergo allogeneic HSCT. POST-HSCT GILTERITINIB MAINTENANCE: Beginning 30-120 days after completion of HSCT, patients receive gilteritinib PO or NG or G tube QD on days 1-365. ARM BD HIGH RISK GROUP: CONTINUED INDUCTION 1 (WITH GILTERITINIB): Patients receive CPX-351 IV over 90 minutes on days 1, 3, and 5, gemtuzumab ozogamicin IV over 2 hours on day 6, and gilteritinib PO QD on days 11-31. Patients with CNS1 receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 8. Patients with CNS2, CNS3a, and CNS3b receive methotrexate IT, hydrocortisone IT, and cytarabine IT QW starting on day 8 for 4-6 weeks (may continue into Induction 2) until the CSF is clear of blasts (CNS1 status). Patients with CNS3c receive methotrexate IT, hydrocortisone IT, and cytarabine IT QW starting on day 1 for 6 weeks (may continue into Induction 2). INDUCTION 2 (WITH GILTERITINIB): Patients with CNS1 receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 0. Patients with CNS2 receive methotrexate IT, hydrocortisone IT, and cytarabine IT QW starting on day 0 until CNS1 status is reached. Patients also receive CPX-351 IV over 90 minutes on days 1, 3, and 5 and gilteritinib PO QD on days 11-31. INTENSIFICATION 1 (WITH GILTERITINIB): Patients receive methotrexate IT, hydrocortisone IT, and cytarabine IT on day 0. Patients also receive high-dose cytarabine IV over 1-3 hours Q12H and etoposide IV over 90-120 minutes on days 1-5, and gilteritinib PO QD on days 6-26. HSCT: After completion of Intensification 1 and investigator assigned conditioning regimen, patients undergo allogeneic HSCT. POST-HSCT GILTERITINIB MAINTENANCE: Beginning 30-120 days after completion of HSCT, patients receive gilteritinib PO or NG or G tube QD on days 1-365. NOTE: During Induction 2 or Intensification 2, patients in Arms A and B with left ventricular systolic dysfunction receive a replacement course of high-dose cytarabine IV over 3 hours on days 1, 2, 8, and 9, and asparaginase Erwinia chrysanthemi IM or IV over 1-2 hours. Patients in Arms AC, BC, AD, and BD receive treatment as in Arms A and B and also receive gilteritinib PO QD on days 10-30 (Induction 2) or days 10-30 (Intensification 2). OPTIONAL NEUROCOGNITIVE STUDY: Patients may complete the Cogstate assessment battery at the end.