Safety and tolerability of AMG 330 in adults with relapsed/refractory AML: a phase 1a dose-escalation study.

AMG 330, a bispecific T-cell engager (BiTE®) that binds CD33 and CD3 on T cells facilitates T-cell-mediated cytotoxicity against CD33+ cells. This first-in-human, open-label, dose-escalation study evaluated the safety, pharmacokinetics, pharmacodynamics, and preliminary efficacy of AMG 330 in adults with relapsed/refractory acute myeloid leukemia (R/R AML). Amongst 77 patients treated with AMG 330 (0.5 µg/day-1.6 mg/day) on 14-day or 28-day cycles, maximum tolerated dose was not reached; median duration of treatment was 29 days. The most frequent treatment-related adverse events were cytokine release syndrome (CRS; 78%) and rash (30%); 10% of patients experienced grade 3/4 CRS. CRS was mitigated with stepwise dosing of AMG 330, prophylactic dexamethasone, and early treatment with tocilizumab. Among 60 evaluable patients, eight achieved complete remission or morphologic leukemia-free state; of the 52 non-responders, 37% had ≥50% reduction in AML bone marrow blasts. AMG 330 is a promising CD33-targeted therapeutic strategy for R/R AML.

Assessment of an embedded primary care-derived electronic health record (EHR) frailty index (eFI) in older adults with acute myeloid leukemia.

INTRODUCTION: Assessing frailty is integral to treatment decision-making for older adults with acute myeloid leukemia (AML). Prior electronic frailty indices (eFI) derive from an accumulated-deficit model and are associated with mortality in older primary care populations. We evaluated use of an embedded eFI in AML by describing baseline eFI categories by treatment type and exploring associations between eFI categories, survival, and treatment received. MATERIALS AND METHODS: This was a retrospective study of subjects ≥60 years old with new AML treated at an academic medical center from 1/2018-10/2020. The eFI requires ≥2 ambulatory visits over two years and uses demographics, vitals, ICD-10 codes, outpatient labs, and available functional information from Medicare Annual Wellness Visits. Frailty was defined as fit (eFI ≤ 0.10), pre-frail (0.10 < eFI ≤ 0.21), and frail (eFI > 0.21). Chemotherapy was intensive (anthracycline-based) or less-intensive (hypomethylating agent, low dose cytarabine +/- venetoclax). Therapy type, pre-treatment characteristics, and chemotherapy cycles were compared by eFI category using chi-square and Fisher's exact tests and ANOVA. Median survival was compared by eFI category using log-rank tests stratified by therapy type. RESULTS: Among 166 older adults treated for AML (mean age 74 years, 61% male, 85% Caucasian), only 79 (48%) had a calculable eFI score before treatment. Of these, baseline eFI category was associated with treatment received (fit (n = 31): 68% intensive, 32% less intensive; pre-frail (n = 38): 37% intensive, 63% less intensive; frail (n = 10): 0% intensive, 100% less intensive; not calculable (n = 87): 48% intensive, 52% less-intensive; p < 0.01). The prevalence of congestive heart failure and secondary AML differed by frailty status (p < 0.01). Median survival did not differ between eFI categories for intensively (p = 0.48) or less-intensively (p = 0.09) treated patients. For those with less-intensive therapy who lived ≥6 months, eFI category was not associated with the number of chemotherapy cycles received (p = 0.97). The main reason for an incalculable eFI was a lack of outpatient visits in our health system prior to AML diagnosis. DISCUSSION: A primary care-derived eFI was incalculable for half of older adults with AML at an academic medical center. Frailty was associated with chemotherapy intensity but not survival or treatment duration. Next steps include testing adaptations of the eFI to the AML setting.

Comparison of survival for metastatic pancreatic cancer patients treated with CPI-613 versus resected borderline-resectable pancreatic cancer patients.

INTRODUCTION: Treatment of advanced pancreatic adenocarcinoma remains suboptimal. Therapeutic agents with a novel mechanism of action are desperately needed; one such novel agent is CPI-613 targets. We here analyze the outcomes of 20 metastatic pancreatic cancer patients treated with CPI-613 and FOLFIRINOX in our institution and evaluate their outcomes to borderline-resectable patients treated with curative surgery. METHODS: A post hoc analysis was performed of the phase I CPI-613 trial data (NCT03504423) comparing survival outcomes to borderline-resectable cases treated with curative resection at the same institution. Survival was measured by overall survival (OS) for all study cases and disease-free survival (DFS) for resected cases with progression-free survival for CPI-613 cases. RESULTS: There were 20 patients in the CPI-613 cohort and 60 patients in the surgical cohort. Median follow-up times were 441 and 517 days for CPI-613 and resected cases, respectively. There was no difference in survival times between CPI-613 and resected cases with a mean OS of 1.8 versus 1.9 year (p = 0.779) and mean PFS/DFS of 1.4 versus 1.7 years (p = 0.512). There was also no difference in 3-year survival rates for OS (hazard ratio [HR] = 1.063, 95% confidence interval [CI] 0.302-3.744, p = 0.925) or DFS/PFS (HR = 1.462, 95% CI 0.285-7.505, p = 0.648). CONCLUSION: The first study to evaluate the survival between metastatic patients treated with CPI-613 versus borderline-resectable cases undergoing curative resection. Analysis revealed no significant differences in survival outcomes between the cohorts. Study results are suggestive that there may be potential utility with the addition of CPI-613 to potentially resectable pancreatic adenocarcinoma, although additional research with more comparable study groups are required.

Real-world outcomes of adult patients with acute lymphoblastic leukemia treated with a modified CALGB 10102 regimen.

Acute lymphoblastic leukemia (ALL) is an aggressive bone marrow cancer with disparate outcomes. Data on patient outcomes in real world settings outside of clinical trials is limited. The current study reports on outcomes for 137 ALL patients who received an adult induction and consolidation regimen derived from the CALGB 10102 trial modified without alemtuzumab. Of the 137 patients, 32 were < 40 years old, 52 were between 40 and 59, and 53 were ≥ 60 years old. Overall, 109 (79.6%) patients achieved a complete remission (< 40: 96.1%, 40-59: 86.5%, and 62.3% ≥ 60 (p = 0.0002)). Progression free survival for the entire cohort was 13.5 months and by age was 19.8 months for less than 40, 23.4 months for 40 to 59 and 6.7 months for ≥ 60; p = 0.0002. Median survival was 22.1 months for the entire cohort (32.9 months for ages < 40, 26.6 months ages 40-59, 7.8 months ≥ 60, p < 0.001).

Pyruvate Dehydrogenase Inhibition Leads to Decreased Glycolysis, Increased Reliance on Gluconeogenesis and Alternative Sources of Acetyl-CoA in Acute Myeloid Leukemia.

Acute myeloid leukemia (AML) is an aggressive disease characterized by poor outcomes and therapy resistance. Devimistat is a novel agent that inhibits pyruvate dehydrogenase complex (PDH). A phase III clinical trial in AML patients combining devimistat and chemotherapy was terminated for futility, suggesting AML cells were able to circumvent the metabolic inhibition of devimistat. The means by which AML cells resist PDH inhibition is unknown. AML cell lines treated with devimistat or deleted for the essential PDH subunit, PDHA, showed a decrease in glycolysis and decreased glucose uptake due to a reduction of the glucose transporter GLUT1 and hexokinase II. Both devimistat-treated and PDHA knockout cells displayed increased sensitivity to 2-deoxyglucose, demonstrating reliance on residual glycolysis. The rate limiting gluconeogenic enzyme phosphoenolpyruvate carboxykinase 2 (PCK2) was significantly upregulated in devimistat-treated cells, and its inhibition increased sensitivity to devimistat. The gluconeogenic amino acids glutamine and asparagine protected AML cells from devimistat. Non-glycolytic sources of acetyl-CoA were also important with fatty acid oxidation, ATP citrate lyase (ACLY) and acyl-CoA synthetase short chain family member 2 (ACSS2) contributing to resistance. Finally, devimistat reduced fatty acid synthase (FASN) activity. Taken together, this suggests that AML cells compensate for PDH and glycolysis inhibition by gluconeogenesis for maintenance of essential glycolytic intermediates and fatty acid oxidation, ACLY and ACSS2 for non-glycolytic production of acetyl-CoA. Strategies to target these escape pathways should be explored in AML.

P2RY2-AKT activation is a therapeutically actionable consequence of XPO1 inhibition in acute myeloid leukemia.

Selinexor is a first-in-class inhibitor of the nuclear exportin XPO1 that was recently approved by the US Food and Drug Administration for the treatment of multiple myeloma and diffuse large B-cell lymphoma. In relapsed/refractory acute myeloid leukemia (AML), selinexor has shown promising activity, suggesting that selinexor-based combination therapies may have clinical potential. Here, motivated by the hypothesis that selinexor's nuclear sequestration of diverse substrates imposes pleiotropic fitness effects on AML cells, we systematically catalog the pro- and anti-fitness consequences of selinexor treatment. We discover that selinexor activates PI3Kγ-dependent AKT signaling in AML by upregulating the purinergic receptor P2RY2. Inhibiting this axis potentiates the anti-leukemic effects of selinexor in AML cell lines, patient-derived primary cultures and multiple mouse models of AML. In a syngeneic, MLL-AF9-driven mouse model of AML, treatment with selinexor and ipatasertib outperforms both standard-of-care chemotherapy and chemotherapy with selinexor. Together, these findings establish drug-induced P2RY2-AKT signaling as an actionable consequence of XPO1 inhibition in AML.

Phase II trial of cytarabine and mitoxantrone with devimistat in acute myeloid leukemia.

Devimistat is a TCA cycle inhibitor. A previously completed phase I study of devimistat in combination with cytarabine and mitoxantrone in patients with relapsed or refractory AML showed promising response rates. Here we report the results of a single arm phase II study (NCT02484391). The primary outcome of feasibility of maintenance devimistat following induction and consolidation with devimistat in combination with high dose cytarabine and mitoxantrone was not met, as maintenance devimistat was only administered in 2 of 21 responders. The secondary outcomes of response (CR + CRi) and median survival were 44% (21/48) and 5.9 months respectively. There were no unexpected toxicities observed. An unplanned, post-hoc analysis of the phase I and II datasets suggests a trend of a dose response in older but not younger patients. RNA sequencing data from patient samples reveals an age-related decline in mitochondrial gene sets. Devimistat impairs ATP synthesis and we find a correlation between mitochondrial membrane potential and sensitivity to chemotherapy. Devimistat also induces mitochondrial reactive oxygen species and turnover consistent with mitophagy. We find that pharmacological or genetic inhibition of mitochondrial fission or autophagy sensitizes cells to devimistat. These findings suggest that an age related decline in mitochondrial quality and autophagy may be associated with response to devimistat however this needs to be confirmed in larger cohorts with proper trial design.

Adenosine Monophosphate Activated Protein Kinase (AMPK) enhances chemotherapy response in Acute Myeloid Leukemia (AML).

Adenosine monophosphate activated protein kinase (AMPK) is a master regulator of cell metabolism and is involved in cancer as both a tumor suppressor and a source of resistance to metabolic stress. The role of AMPK in response to chemotherapy has been examined in solid tumor models but remains unclear in acute myeloid leukemia (AML). To determine the role of AMPK in chemotherapy response, AML cell lines were generated lacking AMPK activity. AMPK knock out cells demonstrated significant resistance to cytarabine and doxorubicin both in vitro and in vivo. Mitochondrial mass and function were unchanged in AMPK knockout cells. Mechanistically, AMPK knock out cells demonstrated a diminished DNA damage response with significantly lower γH2AX foci, p53 and p21 induction as well as decreased apoptosis following chemotherapy exposure. Most importantly, TCGA datasets revealed that patients expressing low levels of the PRKAA1 subunit of AMPK had significantly shorter survival. Finally, AML cells were sensitized to chemotherapy with the addition of the AMPK activator AICAR. These data demonstrate that AMPK sensitizes AML cells to chemotherapy and suggests a contribution of the cellular metabolic state to cell fate decisions ultimately affecting therapy response.

hDirect-MAP: projection-free single-cell modeling of response to checkpoint immunotherapy.

There is a lack of robust generalizable predictive biomarkers of response to immune checkpoint blockade in multiple types of cancer. We develop hDirect-MAP, an algorithm that maps T cells into a shared high-dimensional (HD) expression space of diverse T cell functional signatures in which cells group by the common T cell phenotypes rather than dimensional reduced features or a distorted view of these features. Using projection-free single-cell modeling, hDirect-MAP first removed a large group of cells that did not contribute to response and then clearly distinguished T cells into response-specific subpopulations that were defined by critical T cell functional markers of strong differential expression patterns. We found that these grouped cells cannot be distinguished by dimensional-reduction algorithms but are blended by diluted expression patterns. Moreover, these identified response-specific T cell subpopulations enabled a generalizable prediction by their HD metrics. Tested using five single-cell RNA-seq or mass cytometry datasets from basal cell carcinoma, squamous cell carcinoma and melanoma, hDirect-MAP demonstrated common response-specific T cell phenotypes that defined a generalizable and accurate predictive biomarker.

A Pilot Phase II Study of the Feasibility and Efficacy of Vincristine Sulfate Liposome Injection in Patients With Relapsed or Refractory Acute Myeloid Leukemia.

BACKGROUND: Resistance to therapy and a poor outcome characterize relapsed or refractory acute myeloid leukemia (AML). There is a clear need for additional palliative approaches with acceptable toxicities. Vincristine sulfate liposome injection (VSLI) confers enhanced pharmacokinetics and activity when compared to the parent compound. It is effective and well tolerated in heavily pretreated acute lymphoblastic leukemia (ALL) patients. Preclinically VSLI has activity in vincristine-resistant cancers. As relapsed or refractory AML patients would have minimal exposure to vincristine it was hypothesized that VSLI would be well tolerated and may have activity. METHODS: A pilot phase II clinical trial was conducted. Five patients with relapsed or refractory disease were treated using the Food and Drug Administration (FDA)-approved dose and schedule. RESULTS: Of the five patients treated none completed more than one cycle; there were no responses and two patients did not complete one cycle of therapy. Surprisingly, three of the five patients had treatment-related constipation, and two had neuropathy consistent with the known toxicities of VSLI. Given the toxicity and lack of response, the trial was terminated early. CONCLUSIONS: VSLI had no activity against relapsed or refractory AML in this limited, single institution dataset.

Efficacy of 10-day decitabine in acute myeloid leukemia.

The azanucleotide decitabine is used in the treatment of acute myeloid leukemia (AML). Studies have shown conflicting results with 10-day regimens used in previously untreated AML patients. Additionally, there is little data on 10-day decitabine regimens in the relapsed setting. This study investigated outcomes of 108 adult patients with AML in the upfront and relapsed setting treated with a 10-day decitabine regimen. In the upfront group, the overall response rate (ORR, CR + CRi) was 36.1% and the median overall survival (OS) was 6.6 months, while the relapsed/refractory group had an ORR of 25% with an OS of 4.8 months. When analyzed with respect to cytogenetics, the upfront group featured an ORR of 28.1% with an OS of 9.4 months in the intermediate cytogenetic cohort compared to a 40.5% ORR and an OS of 5.4 months in the unfavorable cytogenetic cohort. An analysis of the relapsed/refractory group demonstrated an ORR of 26.3% with an OS of 7.9 months for intermediate cytogenetics versus 25.0% with an OS of 1.8 months in the unfavorable cohort. While these response rates are similar to previously published data, the median OS appears shorter.

Safety and efficacy of BAY1436032 in IDH1-mutant AML: phase I study results.

The mutant IDH1 (mIDH1) inhibitor BAY1436032 demonstrated robust activity in preclinical AML models, supporting clinical evaluation. In the current dose-escalation study, BAY1436032 was orally administered to 27 mIDH1 AML subjects across 4 doses ranging from 300 to 1500 mg twice-daily. BAY1436032 exhibited a relatively short half-life and apparent non-linear pharmacokinetics after continuous dosing. Most subjects experienced only partial target inhibition as indicated by plasma R-2HG levels. BAY1436032 was safe and a maximum tolerated dose was not identified. The median treatment duration for all subjects was 3.0 months (0.49-8.5). The overall response rate was 15% (4/27; 1 CRp, 1 PR, 2 MLFS), with responding subjects experiencing a median treatment duration of 6.0 months (3.9-8.5) and robust R-2HG decreases. Thirty percent (8/27) achieved SD, with a median treatment duration of 5.5 months (3.1-7.0). Degree of R-2HG inhibition and clinical benefit did not correlate with dose. Although BAY1436032 was safe and modestly effective as monotherapy, the low overall response rate and incomplete target inhibition achieved at even the highest dose tested do not support further clinical development of this investigational agent in AML.

The Novel Phospholipid Mimetic KPC34 Is Highly Active Against Acute Myeloid Leukemia with Activated Protein Kinase C.

Acute myeloid leukemia (AML) is an aggressive malignancy with poor outcomes. Nucleoside analogs are subject to resistance mechanisms including downregulation of equilibrative nucleoside transporter (ENT1) and deoxycytidine kinase (dCK). KPC34 is a novel phospholipid mimetic that when cleaved by phospholipase C (PLC) liberates gemcitabine monophosphate and a diacylglycerol mimetic that inhibits the classical isoforms of protein kinase C (PKC). KPC34 acts independently of ENT1 and dCK. KPC34 was active against all AML cell lines tested with IC50s in the nanomolar range. Enforced expression of PLC increased response to KPC34 in vivo. In an orthotopic, xenograft model, KPC34 treatment resulted in a significant increase in survival compared to control animals and those treated with high-dose cytarabine. In a PDX model with activated PKC, there was a significant survival benefit with KPC34, and at progression, there was attenuation of PKC activation in the resistant cells. In contrast, KPC34 was ineffective against a syngeneic, orthotopic AML model without activated PKC. However, when cells from that model were forced to express PKC, there were significantly increased sensitivity in vitro and survival benefit in vivo. These data suggest that KPC34 is active against AML and that the presence of activated PKC can be a predictive biomarker.

Combination of dasatinib with chemotherapy in previously untreated core binding factor acute myeloid leukemia: CALGB 10801.

Acute myeloid leukemia (AML) with either t(8;21)(q22;q22) or inv(16)(p13q22)/t(16;16)(p13;q22) is referred to as core binding factor (CBF) AML. Although categorized as favorable risk, long-term survival for these patients is only ∼50% to 60%. Mutated (mut) or overexpressed KIT, a gene encoding a receptor tyrosine kinase, has been found almost exclusively in CBF AML and may increase the risk of disease relapse. We tested the safety and clinical activity of dasatinib, a multi-kinase inhibitor, in combination with chemotherapy. Sixty-one adult patients with AML and CBF fusion transcripts (RUNX1/RUNX1T1 or CBFB/MYH11) were enrolled on Cancer and Leukemia Group B (CALGB) 10801. Patients received cytarabine/daunorubicin induction on days 1 to 7 and oral dasatinib 100 mg/d on days 8 to 21. Upon achieving complete remission, patients received consolidation with high-dose cytarabine followed by dasatinib 100 mg/d on days 6 to 26 for 4 courses, followed by dasatinib 100 mg/d for 12 months. Fifteen (25%) patients were older (aged ≥60 years); 67% were CBFB/MYH11-positive, and 19% harbored KITmut. There were no unexpected or dose-limiting toxicities. Fifty-five (90%) patients achieved complete remission. With a median follow-up of 45 months, only 16% have relapsed. The 3-year disease-free survival and overall survival rates were 75% and 77% (79% and 85% for younger patients [aged <60 years], and 60% and 51% for older patients). Patients with KITmut had comparable outcome to those with wild-type KIT (3-year rates: disease-free survival, 67% vs 75%; overall survival, 73% vs 76%), thereby raising the question of whether dasatinib may overcome the negative impact of these genetic lesions. CALGB 10801 was registered at www.clinicaltrials.gov as #NCT01238211.

The prognostic value of standardized phase angle in adults with acute leukemia: A prospective study.

Standardized phase angle (SPhA) is a tool used to estimate body composition and cell membrane integrity. Standardized phase angle has been shown to predict survival in solid malignancies and hematopoietic stem cell transplant patients. We investigated the predictive value of SPhA on 60-day mortality, overall survival (OS), and length of hospital stay (LHS) for adults with acute myelogenous and lymphoblastic leukemia (AML and ALL). Consecutive patients ≥18 years with newly diagnosed acute leukemia receiving intensive chemotherapy were enrolled. Phase angle measurements were taken on day 1 of therapy for all patients and on the day of nadir marrow for AML patients. Measurements were standardized by BMI, gender, and age to calculate the SPhA. The difference between SPhA at nadir bone marrow compared to day 1 of induction was used to calculate change in SPhA. A cutoff of 25th percentile was used to dichotomize baseline SPhA. Among 100 patients, 88% were AML, 56% were female, and mean age was 59 years. Though not statistically significant, OS by Kaplan-Meier analysis was shorter for those below the 25th percentile SPhA compared to those above (median OS: 11.0 months vs 19.5 months; P = .09). Lower baseline SPhA was associated with increased incidence of 60-day mortality in univariable (odds ratio [OR] = 5.25; 1.35, 20.44; P = .02) but not multivariable analysis (OR = 3.12; 0.67, 14.48; P = .15) adjusted for age, creatinine, and cytogenetics. Increased change in SPhA was associated with worse OS (hazard ratio = 1.15; 1.00,1.33; P = .05) in multivariable analysis. Standardized phase angle is a rapid, noninvasive, and objective measure that may be used to inform risk stratification.

Inflammatory biomarkers, geriatric assessment, and treatment outcomes in acute myeloid leukemia.

OBJECTIVES: To investigate changes in inflammatory biomarkers during induction therapy for older adults with acute myeloid leukemia (AML) and their associations with geriatric assessment (GA) measures and outcomes. METHODS: This was a single institution ancillary study to a prospective observational study (N = 20 consecutive adults aged ≥60 with newly diagnosed AML who received induction chemotherapy). Biomarkers (Interleukin-6 [IL-6], IL-6 soluble receptor [IL-6 sR], tumor necrosis factor alpha [TNFα], TNFα soluble receptor 1 [TNFα sR1], interleukin-3 [IL-3], C-reactive protein [CRP]) were collected at start of induction, weekly for three weeks, and post-induction and were compared over time using paired t-tests. GA was administered at baseline and post-induction, and correlated with biomarker levels using Spearman correlations. Survival was estimated using Kaplan-Meier and compared by categorized biomarker level using Wilcoxon tests. RESULTS: Biomarker levels were stable during induction, except for CRP and IL-6 sR. Declines in objectively measured physical function [Short Physical Performance Battery (SPPB); r = 0.71, p < 0.01] and increases in self-reported limitation in instrumental activities of daily living (r = 0.81, p < 0.01) were correlated with increased TNFα sR1. Declines in SPPB were correlated with increased CRP (r = -0.73, p < 0.01). Improvement in depression was correlated with increased IL-6 sR (r = -0.59 p = 0.02). Survival was shorter in those with baseline TNFα or CRP levels above the median (6.1 vs. 40.2 months and 5.5 vs. 27.6 months respectively, p = 0.04 for both). CONCLUSION: Among older adults with AML, the relationships between TNFα sR1, CRP, and IL-6 sR with change in physical and emotional health during treatment warrants further investigation.

Gilteritinib or Chemotherapy for Relapsed or Refractory FLT3-Mutated AML.

BACKGROUND: Patients with relapsed or refractory acute myeloid leukemia (AML) with mutations in the FMS-like tyrosine kinase 3 gene (FLT3) infrequently have a response to salvage chemotherapy. Gilteritinib is an oral, potent, selective FLT3 inhibitor with single-agent activity in relapsed or refractory FLT3-mutated AML. METHODS: In a phase 3 trial, we randomly assigned adults with relapsed or refractory FLT3-mutated AML in a 2:1 ratio to receive either gilteritinib (at a dose of 120 mg per day) or salvage chemotherapy. The two primary end points were overall survival and the percentage of patients who had complete remission with full or partial hematologic recovery. Secondary end points included event-free survival (freedom from treatment failure [i.e., relapse or lack of remission] or death) and the percentage of patients who had complete remission. RESULTS: Of 371 eligible patients, 247 were randomly assigned to the gilteritinib group and 124 to the salvage chemotherapy group. The median overall survival in the gilteritinib group was significantly longer than that in the chemotherapy group (9.3 months vs. 5.6 months; hazard ratio for death, 0.64; 95% confidence interval [CI], 0.49 to 0.83; P<0.001). The median event-free survival was 2.8 months in the gilteritinib group and 0.7 months in the chemotherapy group (hazard ratio for treatment failure or death, 0.79; 95% CI, 0.58 to 1.09). The percentage of patients who had complete remission with full or partial hematologic recovery was 34.0% in the gilteritinib group and 15.3% in the chemotherapy group (risk difference, 18.6 percentage points; 95% CI, 9.8 to 27.4); the percentages with complete remission were 21.1% and 10.5%, respectively (risk difference, 10.6 percentage points; 95% CI, 2.8 to 18.4). In an analysis that was adjusted for therapy duration, adverse events of grade 3 or higher and serious adverse events occurred less frequently in the gilteritinib group than in the chemotherapy group; the most common adverse events of grade 3 or higher in the gilteritinib group were febrile neutropenia (45.9%), anemia (40.7%), and thrombocytopenia (22.8%). CONCLUSIONS: Gilteritinib resulted in significantly longer survival and higher percentages of patients with remission than salvage chemotherapy among patients with relapsed or refractory FLT3-mutated AML. (Funded by Astellas Pharma; ADMIRAL ClinicalTrials.gov number, NCT02421939.).