NUP98-NSD1-positive acute myeloid leukemia (AML) is a poor prognostic subgroup that is frequently diagnosed in pediatric cytogenetically normal AML. NUP98-NSD1-positive AML often carries additional mutations in genes including FLT3, NRAS, WT1, and MYC. The purpose of our study was to characterize the cooperative potential of the fusion and its associated Neuroblastoma rat sarcoma (NRAS) mutation. By constitutively expressing NUP98-NSD1 and NRASG12D in a syngeneic mouse model and using a patient-derived xenograft (PDX) model from a NUP98-NSD1-positive AML patient, we evaluated the functional role of these genes and tested a novel siRNA formulation that inhibits the oncogenic driver NUP98-NSD1. NUP98-NSD1 transformed murine bone marrow (BM) cells in vitro and induced AML in vivo. While NRASG12D expression was insufficient to transform cells alone, co-expression of NUP98-NSD1 and NRASG12D enhanced the leukemogenicity of NUP98-NSD1. We developed a NUP98-NSD1-targeting siRNA/lipid nanoparticle formulation that significantly prolonged the survival of the PDX mice. Our study demonstrates that mutated NRAS cooperates with NUP98-NSD1 and shows that direct targeting of the fusion can be exploited as a novel treatment strategy in NUP98-NSD1-positive AML patients.

Atrial fibrillation (AF) is the most common arrhythmia in adults but its impact on allogeneic stem cell transplantation (SCT) is not well characterized. We studied AF manifestation during the hospital stay for allogeneic SCT, referred to as AF in hospital (AFiH), and analyzed the incidence of, risk factors for, and clinical impact of AFiH on intensive care unit (ICU)-/hospital-/ and overall survival (OS), relapse-free survival (RFS), nonrelapse mortality (NRM), and graft-versus-host disease (GVHD)-free, relapse-free survival (GRFS). This retrospective matched cohort study comprised 553 consecutive SCT recipients at Hannover Medical School between January 2013 and October 2019. Patients with AFiH were compared with a non-AFiH control cohort matched for Hematopoietic Stem Cell-Specific Comorbidity Index (HCT-CI), European Group for Blood and Marrow Transplantation (EBMT) risk score, disease, conditioning regimen and availability of molecular genetic data for patients with myeloid diseases. AFiH occurred in 46 patients (8%) at a median of 2 days (interquartile range, 0 to 8 days) after SCT. Patient history of AF and elevated NT-proBNP and high-sensitivity troponin T levels, but not conventional echocardiographic parameters, were predictive for AFiH. AFiH occurred more often in patients with mutations in DNMT3A, TET2, and ASXL1 genes related to clonal hematopoiesis compared with patients with wild-type alleles, with the greatest impact from DMT3A mutations. ICU admission was significantly higher in the AFiH cohort (46% versus 7%), without significant differences in ICU or post-ICU hospital survival (62% versus 40% and 52% versus 40%, respectively). The main cause of death was sepsis. In terms of long-term outcomes, the incidences of relapse and grade II-IV acute GVHD did not differ significantly between the AFiH and the non-AFiH groups; however, OS was significantly shorter in the AFiH group (1 year OS, 39% versus 65%), owing to late noncardiac NRM (1 year NRM, 49% versus 27%). Although the underlying cellular and molecular mechanisms remain to be characterized in further detail, these data clearly demonstrate the impact of inpatient AF manifestation/AFiH on long-term outcomes of SCT recipients.

Donor lymphocyte infusions (DLIs) can directly target leukemic cells through a graft-versus-leukemia effect and play a key role in the prevention and management of relapse after allogeneic hematopoietic cell transplantation (alloHCT). Predictors of response to DLIs are not well established. We evaluated measurable residual disease (MRD) before, 30 and 90 days after DLI treatment as biomarkers of response. MRD was assessed by next-generation sequencing in 76 DLI-treated acute myeloid leukemia patients. MRD status before DLI treatment was independently prognostic for event-free survival (EFS, p < 0.001) and overall survival (OS, p < 0.001). Within 90 days of DLI treatment, 73% of MRD⁺ patients converted to MRD⁻ and 32% of patients without remission achieved remission. MRD status 90 days after DLI treatment was independently prognostic for the cumulative incidence of relapse (CIR, p = 0.011) and relapse-free survival (RFS, p = 0.001), but not for OS. To evaluate the role of DLI treatment in MRD⁻ patients, 23 MRD⁻ patients who received DLIs were compared with a control cohort of 68 MRD⁻ patients not receiving DLIs. RFS (p = 0.23) and OS (p = 0.48) were similar between the two cohorts. In conclusion, MRD is prognostic before (EFS, OS) and after (CIR, RFS) DLI treatment and may help in the selection of patients who benefit most from DLIs.

Chronic kidney disease (CKD) before treatment and renal function decline during treatment are common in elderly patients receiving hypomethylating agents (HMAs) and venetoclax (VEN). This retrospective multicenter study of 130 newly diagnosed older acute myeloid leukemia (AML) patients evaluated the prognostic impact of renal function before and during the first treatment cycle. A total of 56 patients (43%) had CKD, and 49 (38%) developed acute kidney injury (AKI) during treatment. AKI occurrence was associated with laboratory tumor lysis syndrome (LTLS). CKD before treatment showed a trend towards a lower overall response rate (ORR, OR 0.5, p = 0.07) in multivariable analysis (MVA) and inferior relapse-free survival (RFS, HR 2.16, p = 0.06) in univariate analysis (UVA), but not MVA (RFS, HR 1.93, p = 0.15). CKD did not affect overall survival (OS) or event-free survival (EFS). AKI during HMA/VEN therapy was associated with significantly higher 30-day and 60-day mortality rates and emerged as an independent prognostic factor for inferior OS (HR 1.86, p = 0.01) and EFS (HR 1.81, p = 0.007). RFS did not differ significantly by AKI status. Sepsis was a more frequent cause of death in patients with vs. without AKI (33% vs. 5%). In conclusion, kidney function is a key prognostic factor in HMA/VEN-treated patients, warranting further study on treatment adjustments and supportive care.

Acute myeloid leukemia (AML) is characterized by recurrent chromosomal abnormalities that form the basis of the European LeukemiaNet (ELN) risk classification and serve as essential determinants of prognosis and therapeutic decision-making. Conventional metaphase karyotyping remains the diagnostic gold standard for detecting these abnormalities; however, its utility is limited by longer turnaround times, often delaying critical clinical management. Here, we present a long-read sequencing-based (LRS) low-coverage whole genome sequencing (lcWGS) approach using Oxford Nanopore Technology as a rapid and scalable alternative for cytogenetic profiling. A total of 100 diagnostic AML samples were analyzed, comprising 50 retrospectively selected cases with known adverse-risk cytogenetics and 50 prospectively enrolled patients with clinically defined de novo AML. LcWGS demonstrated robust analytical performance, identifying chromosomal aberrations with 93% sensitivity, specificity, and overall accuracy, respectively. Complex karyotypes were reliably detected, with an area under the curve (AUC) of 0.971. Reproducibility was validated through replicate sequencing at two independent laboratories (R=0.99). LcWGS-derived estimates of clone size showed moderate correlation with conventional cytogenetic assessments (R=0.54). Patients with complex karyotypes identified by lcWGS exhibited significantly shorter overall and relapse-free survival, closely mirroring outcomes defined by conventional karyotyping and underscoring the value of lcWGS for risk stratification. Median turnaround time from sample receipt to bioinformatics interpretation was approximately 34 hours, enabling delivery of actionable karyotype results within 72 hours. These findings establish lcWGS as a rapid, reproducible, and accurate platform for detecting clinically relevant chromosomal abnormalities, addressing a critical need for timely risk stratification and treatment initiation in AML.