CD34+ Cell Dose, Measurable Residual Disease, and Outcome After Myeloablative HLA-Matched Peripheral Blood Hematopoietic Cell Transplantation for Adults with Acute Myeloid Leukemia.

: The impact of donor graft cell composition on post-HCT outcomes in AML remains controversial. Furthermore, it is unknown whether this interacts with pre-HCT MRD status. We evaluated the impact of CD34+ and CD3+ cell doses on outcomes of myeloablative conditioning (MAC) HCT in patients with myelodysplastic neoplasm (MDS)/AML or AML with and without detectable MRD in pre-HCT bone marrow specimens.

Phase 1 trial of venetoclax with cladribine, cytarabine, G-CSF, and mitoxantrone for AML and high-grade myeloid neoplasm.

Intensifying induction by combining venetoclax with a high-dose cytarabine regimen may improve outcomes for high-risk populations such as adult patients with adverse-risk newly diagnosed or relapsed acute myeloid leukemia. In a phase 1 trial testing the novel combination of venetoclax and CLAG-M (cladribine, high-dose cytarabine, granulocyte colony-stimulating factor [G-CSF], and mitoxantrone), the maximum tolerated dose was venetoclax 400 mg on days 1 through 14, combined with cladribine 5 mg/m on days 1 through 5, cytarabine 1.5 g/m on days 1 through 5, G-CSF 5 μg/kg on days 0 through 5, and mitoxantrone 16 or 18 mg/m on days 1 through 3 (for relapsed/refractory and newly diagnosed adverse-risk patients, respectively).

Multiplex base editing to protect from CD33 directed drugs for immune and gene therapy.

The selection of genetically engineered immune or hematopoietic cells in vivo after gene editing remains a clinical problem and requires a method to spare on-target toxicity to normal cells. Here, we develop a base editing approach exploiting a naturally occurring CD33 single nucleotide polymorphism leading to removal of full-length CD33 surface expression on edited cells. CD33 editing in human and nonhuman primate hematopoietic stem and progenitor cells protects myeloid progeny from CD33-targeted therapeutics without affecting normal hematopoiesis in vivo, thus demonstrating potential for improved immunotherapies with reduced off-leukemia toxicity.

Distal gut colonization by oral bacteria during intensive chemotherapy: direct evidence from strain-level analysis of paired samples.

Oral bacteria have been found in the colon in pathologies such as inflammatory bowel disease. To ascertain niche coalescence, 2 elements are essential: (i) paired oral/fecal samples and (ii) strain-level resolution. We profiled the microbiota in 283 samples from 39 patients undergoing intensive chemotherapy at baseline (saliva: 49, plaque: 51, stool: 43), week 2 (saliva: 18, plaque: 17, stool: 17), week 3 (saliva: 18, plaque: 21, stool: 21), and week 4 (saliva: 8, plaque: 10, stool: 10) of chemotherapy.

Predictors of Cardiac Recovery in Adults With AML Who Develop Heart Failure During Treatment.

Purpose: Heart failure is a leading cause of death in patients with AML, who face higher risks of cardiac complications than nonleukemic cancer patients treated with anthracyclines. This study examines factors associated with myocardial dysfunction and recovery occurring during treatment of AML.

Methods: We retrospectively analyzed patients with AML who sustained reduced left ventricular ejection fraction (LVEF) during induction therapy at the University of Washington/Fred Hutchinson Cancer Center (2008-2022).

Significance of Measurable Residual Disease in Patients Undergoing Allogeneic Hematopoietic Cell Transplantation for Acute Myeloid Leukemia.

Allogeneic hematopoietic cell transplantation (HCT) remains an important curative-intent treatment for many patients with acute myeloid leukemia (AML), but AML recurrence after allografting is common. Many factors associated with relapse after allogeneic HCT have been identified over the years. Central among these is measurable ("minimal") residual disease (MRD) as detected by multiparameter flow cytometry, quantitative polymerase chain reaction, and/or next-generation sequencing.

Protection of CD33-modified hematopoietic stem cell progeny from CD33-directed CAR T cells in rhesus macaques.

The treatment of monogenetic disorders, such as hemoglobinopathies and lysosomal storage diseases, has markedly improved with the advent of cell and gene therapies, particularly allogeneic or gene-modified autologous stem cell transplantations. However, therapeutic efficacy is reliant on maintaining engraftment above a critical threshold. To maintain such engraftment levels, we and others have pursued approaches to shield edited cells from antibody or chimeric antigen receptor (CAR) T-cell-mediated selection.

Fitness assessment in acute myeloid leukemia: recommendations from an expert panel on behalf of the European LeukemiaNet.

Fitness assessment in patients with acute myeloid leukemia (AML) is critical to deliver the right therapy to the right patient. Although several scoring systems are available to aid in determining fitness, the absence of validation studies has resulted in the lack of universally accepted assessment procedures. This limitation, combined with the increasing availability of novel agents expanding the spectrum of less-intensive options, has introduced additional complexity to the fitness assessment process.

Relationship between age, conditioning intensity, and outcome after allografting in adults age ≥60 years with AML.

Methodological advancements now allow older adults with AML to receive allografts although conflicting data exist regarding relative outcomes across age groups and benefits of different conditioning intensities. We retrospectively analyzed 495 adults aged 60-64 (n = 184), 65-69 (n = 189), or ≥70 (n = 122) allografted for AML in remission at our institution from 2006 to 2023. There were no significant differences in relapse or relapse-free survival (RFS) among the 3 age cohorts after multivariable adjustment.

Relationship between donor source, pre-transplant measurable residual disease, and outcome after allografting for adults with acute myeloid leukemia.

Lack of HLA-matched related/unrelated donor remains a barrier to allogeneic hematopoietic cell transplantation (HCT) for adult acute myeloid leukemia (AML), with ongoing uncertainty about optimal donor type if more than one alternative donor is available. To assess the relationship between donor type, pre-HCT measurable residual disease (MRD), and post-HCT outcomes, we retrospectively analyzed 1265 myelodysplastic neoplasm (MDS)/AML and AML patients allografted in first or second remission with an HLA-matched sibling (MSD) or unrelated donor (MUD), HLA-mismatched unrelated donor (MMD), an HLA-haploidentical donor, or umbilical cord blood (UCB) at a single institution. Relapse risk was non-significantly higher after HLA-haploidentical and lower after UCB HCT.

Optimizing Siglec-8-Directed Immunotherapy for Eosinophilic and Mast Cell Disorders.

Current treatments for eosinophilic and mast cell disorders are often ineffective. One promising target to improve outcomes is sialic acid-binding immunoglobulin-like lectin-8 (Siglec-8). As limitations, there are few Siglec-8 monoclonal antibodies (mAbs) available to date, and Siglec-8-directed treatments have so far primarily focused on unconjugated mAbs, which may be inadequate, especially against mast cells.

Lower-intensity CPX-351 plus venetoclax induction for adults with newly diagnosed AML unfit for intensive chemotherapy.

Preclinical data suggest a rationale for combining CPX-351, a dual-drug liposomal encapsulation of daunorubicin and cytarabine, with venetoclax, a B-cell lymphoma-2 inhibitor. This phase 1b study evaluated lower-intensity CPX-351 combined with venetoclax in adults with acute myeloid leukemia (AML) considered unfit/ineligible for intensive chemotherapy. In a dose-exploration phase using a 3+3 design, patients received stepwise dosing of CPX-351 IV on days 1 and 3 plus venetoclax 400 mg orally on days 2 to 21 per cycle to determine the recommended phase 2 dose (RP2D) for this combination.

Measurable residual disease as predictor of post-day +100 relapses after allografting in adult AML.

Measurable residual disease (MRD) by multiparametric flow cytometry (MFC) before allogeneic hematopoietic cell transplantation (HCT) identifies patients at high risk of acute myeloid leukemia (AML) relapse, often occurring early after allografting. To examine the role of MFC MRD testing to predict later relapses, we examined 935 adults with AML or myelodysplastic neoplasm/AML transplanted in first or second morphologic remission who underwent bone marrow restaging studies between day 70 and 100 after HCT and were alive and without relapse by day +100. Of 935 adults, 136 (15%) had MRD before HCT, whereas only 11 (1%) had MRD at day +70 to +100.

Allogeneic hematopoietic cell transplantation for acute myeloid leukemia in adults over 70 years old.

The advent of reduced-intensity conditioning regimens, improvements in graft-versus-host disease prophylaxis, and better supportive care have permitted increasing use of allogeneic hematopoietic cell transplantation (allo-HCT) in adults aged ≥70 years with acute myeloid leukemia. However, although potentially curative, nonrelapse mortality and relapse represent the main causes of treatment failure, highlighting the importance of refining both patient selection and transplant strategies. At the same time, continuously evolving nontransplant therapies and transplant technologies mandate prospective trials (re-)examining the role of allo-HCT and its optimal delivery.

Targeting the membrane-proximal C2-set domain of CD33 for improved CAR T cell therapy.

Current CD33-targeted immunotherapies typically recognize the membrane-distal V-set domain of CD33. Here, we show that decreasing the distance between T cell and leukemia cell membrane increases the efficacy of CD33 chimeric antigen receptor (CAR) T cells. We therefore generated and optimized second-generation CAR constructs containing single-chain variable fragments from antibodies raised against the membrane-proximal C2-set domain, which bind CD33 regardless of whether the V-set domain is present (CD33 antibodies).

Relationship between morphologic remission with or without hematologic recovery and outcome after allogeneic hematopoietic cell transplantation in adult acute myeloid leukemia.

Outcomes of adults with AML after allografting vary widely. While numerous covariates have been associated with relapse, non-relapse mortality (NRM), and/or shorter survival, the impact of incomplete blood count recovery before transplantation has remained unclear. To address this uncertainty, we examined all adults with AML or MDS/AML who received an allograft in first or second remission between 2006 and 2023 at a single institution.

Care Patterns and Barriers to Outpatient Care for Adults With AML Following Intensive Chemotherapy at NCCN Member Institutions.

Background: Prolonged hospitalization following intensive (re)induction chemotherapy for acute myeloid leukemia (AML), while standard, is costly and resource intense, limits inpatient bed capacity, and negatively impacts quality of life. Early hospital discharge (EHD) following completion of chemotherapy has proven safe as an alternative at select institutions, but is not widely implemented.

Patients And Methods: From February 2023 through May 2023, the NCCN Best Practices Committee conducted a survey evaluating AML hospitalization patterns, care models, and barriers to EHD at its 33 member institutions.