Venetoclax-obinutuzumab (Ven-Obi) is a standard first-line therapy for chronic lymphocytic leukemia (CLL). The impact of age, fitness, and dose reductions remains unclear. We analyzed patients treated with Ven-Obi in the CLL13 and CLL14 trials, excluding patients with TP53 aberrations. Fitness was assessed using the cumulative illness rating scale (CIRS, >6) and creatinine clearance (≤70 mL/min). Among 410 patients (median age, 67 years), 55.7% were unfit (median age, 72 years) and 44.3% were fit (median age, 58 years). Overall response rate (ORR) was 89.5% in unfit and 96.1% in fit patients. Rates of undetectable minimal residual disease (uMRD) at <10-4 were 80.3% in unfit and 85.1% in fit patients. Progression-free survival (PFS) at 3 years was 86.4% vs 87.5% (hazard ratio, [HR], 1.12; 95% confidence interval [CI], 0.70-1.81; P = .63). Overall survival at 3 years was 91.8% vs 96.9% (HR, 2.02; 95% CI, 0.90-4.55; P = .088). Adverse events included neutropenia (62.7% unfit, 56.9% fit), infusion-related-reactions (44.3% unfit, 56.9% fit), fatigue (15.8% unfit, 35.9% fit), and infections (57.5% unfit, 69.6% fit). Venetoclax dose reductions of <80% occurred in 39.6% of unfit and 17.6% of fit patients, with lower ORR (83.3% vs 98.2%) and uMRD rates (74.2% vs 87.9%) in those with reduced dose intensities, but similar PFS. Dose reductions of <70% were associated with shorter PFS. Overall, this study shows comparable efficacy and toxicity of Ven-Obi in fit and unfit patients with CLL.

Obesity is a major health issue and a risk factor for venous thromboembolic disease. Plasminogen activator inhibitor 1 (PAI-1), encoded by the gene SERPINE1, is a negative regulator of fibrinolysis and has been associated with obesity. The liver, which senses obesity-induced metabolic stress, is a key determinant of circulating PAI-1 levels. However, the mechanisms underlying the increased PAI-1 expression in obesity are unclear. This study investigated the upstream regulation of PAI-1 and its role in fibrinolysis and deep vein thrombosis (DVT). Compared with lean mice, diet-induced obesity mice presented significantly shorter fibrinolysis times and larger venous thrombi, largely due to increased hepatocyte expression of PAI-1. A publicly available single-cell RNA sequence data set from the livers of individuals with obesity suggested that increased PAI-1 expression may be related to reduced hepatocyte farnesoid X receptor (FXR) signaling. FXR activation also suppressed Serpine1 mRNA and PAI-1 protein expression levels in both mice and primary mouse hepatocytes (MPHs), but a decrease in PAI-1 in MPHs of Fxr-null mice after FXR activation was not observed. Both Fxr-null mice and Fxrfl/fl mice with AAV8-TBG-Cre exhibited significantly elevated plasma PAI-1, resulting in further impaired fibrinolysis and increased DVT burden. Dual-luciferase reporter assays and chromatin immunoprecipitation suggested that FXR activation directly represses Serpine1 transcription. Importantly, tropifexor treatment of obese mice lowered plasma PAI-1 levels and further alleviated fibrinolysis and the DVT load. These findings suggest that targeting FXR in hepatocytes may improve fibrinolysis and reduce DVT risk.

Acute myeloid leukemia (AML) is characterized by a low 5-year survival rate. Despite having many clinical metrics to assess patient prognosis, there remain opportunities to improve risk stratification. We hypothesized that an underexplored resource to examine the prognosis of patients with AML is plasma metabolome. Circulating metabolites are influenced by patients' clinical status and can serve as accessible cancer biomarkers. To establish a resource of circulating metabolites in genetically diverse patients with AML, we performed an unbiased metabolomic and lipidomic analysis of 231 diagnostic AML plasma samples before treatment with intensive chemotherapy. Intriguingly, circulating metabolites were highly associated with the mutation status within the AML cells. Furthermore, lipids were associated with refractory status. We established a machine learning algorithm trained on chemotherapy-refractory-associated lipids to predict patient survival. Cox regression and Kaplan-Meier analysis demonstrated that the high-risk lipid signature predicted overall survival in this patient cohort. Impressively, the top lipid in the high-risk lipid signature, sphingomyelin (d44:1), was sufficient to predict overall survival in both the original data set and an independent validation data set. Overall, this research underscores the potential of circulating metabolites to capture AML heterogeneity and lipids to be used as potential AML biomarkers.

Fetal hemoglobin reactivation is a promising therapy for β-hemoglobinopathies. We developed a prime editing strategy that introduces multiple mutations in the fetal γ-globin promoters that are expected to increase their activity. We tested multiple targets and optimized a variety of parameters to achieve ∼50% of precise edits in a hematopoietic cell line, with minimal off-target effects. This work improved our understanding of the complex DNA repair mechanisms involved in prime editing. We tested this strategy in patients' hematopoietic stem/progenitor cells. Although editing efficiency was variable among donors, erythroid clones carrying multiple mutations expressed a significantly higher γ-globin level than cells carrying individual mutations, confirming the potential therapeutic benefit of our combined strategy for patients with β-hemoglobinopathies.

Until recently, the JAK1/2 inhibitor ruxolitinib (Jakafi) was the only therapy for steroid-refractory acute graft-versus-host disease approved by the US Food and Drug Administration (FDA) for use in patients aged >12 years. The FDA has now approved a potent mesenchymal stromal cell product, remestemcel-L-rknd (Ryoncil), for children aged ≤18 years, showing 70% response rates and ∼70% 6-month survival. In this spotlight, we highlight this important advance in the field.

Functional high-risk (FHR) multiple myeloma (MM) is defined as an unexpected, early relapse (ER) of disease in the absence of baseline molecular or clinical risk factors (RF), making FHR MM inherently dependent on which RFs were assessed at diagnosis, and what treatment patients received. To establish the true incidence of FHR, we analyzed uniformly treated, transplant-eligible patients from the Myeloma-XI (MyXI) trial that had been profiled for the International Myeloma Society and Working Group (IMS/IMWG) defined high-risk cytogenetic aberrations (HRCA), and the SKY92 gene expression HR signature (GEP-HR). A total of 135 MyXI patients were studied, with a median follow-up of 88 months; 25 (18.5%) experienced ER, defined as relapse <18 months from maintenance randomization post-autologous stem-cell transplantation. Hereof, 15 (60%) were IMS/IMWG-HR at diagnosis, of whom 8 were also GEP-HR. Another 6 patients were GEP-HR only and would have been missed by IMS/IMWG-HR. Among 4 patients with IMS/IMWG- and GEP-standard risk, 2 had isolated HR markers at diagnosis, leaving only 2 patients (8% of ER; 1.5% of all) truly meeting all FHR-criteria. Combined IMS/IMWG-HR and GEP-HR profiling identified 84% of ER, and differentiated long-term outcome across all 135 patients: co-occurring IMS/IMWG and GEP-HR was associated with very short overall survival compared to the absence of both (HR = 13.1; 95% CI, 6.5-26.1, P < .0001), followed by GEP-HR only (HR = 5.1; 95% CI, 2.4-11.1, P < .0001) and IMS/IMWG-HR only (HR = 3.2; 95% CI, 1.6-6.2, P = .0007). Our results support more comprehensive baseline diagnostic profiling to identify those at risk of ER upfront. The trials were registered at the ISRCTN Registry as ISRCTN49407852 and at clinicaltrials.gov as #NCT01554852.

Acute myeloid leukemia (AML) is a highly heterogeneous hematological malignancy that increasingly affects the older population, with its posttranscriptional landscape remaining largely elusive. Establishing a stable proteomics-based classification system and systematically screening age-related proteins and regulatory networks are crucial for understanding the pathogenesis and outcomes of AML. In this study, we leveraged a multiomics cohort of 374 patients newly diagnosed with AML, integrating proteome, phosphoproteome, genome, transcriptome, and drug screening data. Through similarity network fusion clustering, we established 8 proteomic subtypes with distinct clinical and molecular properties, including S1 (CEBPA mutations), S3 (myelodysplasia-related AML), S4 (PML::RARA), S5 (NPM1 mutations), S6 (PML::RARA and RUNX1::RUNX1T1), S8 (CBFB::MYH11), S2 and S7 (mixed), aligning well with and adding actionable value to the latest World Health Organization nomenclature of AML. Hematopoietic lineage profiling of proteins indicated that megakaryocyte/platelet- and immune-related networks characterized distinct aging patterns in AML, which were consistent with our recent findings at the RNA level. Phosphosites also demonstrated distinct age-related features. The high protein abundance of megakaryocytic signatures was observed in S2, S3, and S7 subtypes, which were associated with advanced age and dismal prognosis of patients. A hematopoietic aging score with an independent prognostic value was established based on proteomic data, where higher scores correlated with myelodysplasia-related AML, NPM1 mutations, and clonal hematopoiesis-related gene mutations. Collectively, this study provides an overview of the molecular circuits and regulatory networks of AML during the aging process, advancing current classification systems and offering a comprehensive perspective on the disease.

Platelets are specialized cells for hemostasis which circulate in close contact to the glycocalyx, an extracellular layer of interwoven glycoproteins, proteoglycans, and glycosaminoglycans that maintain vascular homeostasis. Platelets survey their circulating environment, balancing inhibitory signals that prevent inappropriate activation with activating signals that initiate thrombus formation. Disease can disrupt this delicate balance of endogenous inhibitory signaling, leading to an increased risk of thrombosis as in patients with inflammatory bowel disease (IBD). In this study, we demonstrate that physiological concentrations of hyaluronan (HA), an essential component of the glycocalyx, acts as an inhibitor of activation and aggregation in human platelets. Using a combination of affinity chromatography and functional assays of platelets from humans and genetically modified mice, we identify layilin as the receptor for HA and an endogenous inhibitor of platelet activation. Platelets from layilin knockout mice display agonist-induced hyperactivation of αIIbβ3 and increased adhesion to fibrinogen under venous shear. Loss of layilin results in dysregulation of Rho guanosine triphosphatase (GTPase) family members (RAC1, Cdc42, RhoA, and Ras-like Rap1) via layilin's binding partner, merlin, and downstream p21-activated kinase 1. Furthermore, platelets of patients with IBD contain reduced layilin protein levels correlating with heightened basal Rac1-guanosine triphosphate levels and increased reactivity. Finally, although IBD platelets have enhanced sensitivity to activation, pharmacologic inhibition of RAC1 effectively reduces platelet hyperactivity in platelet of patients with IBD. These findings highlight a novel role for layilin and HA in the maintenance of platelet homeostasis that becomes disrupted in patients with IBD.

Older patients with diffuse large B-cell lymphoma (DLBCL) present unfavorable genetic and microenvironmental alterations. In this phase 2 trial, we assessed the efficacy and safety of zanubrutinib in combination with rituximab and lenalidomide (ZR2) in patients with de novo DLBCL aged ≥75 years. Forty patients were enrolled, and the primary end point was the complete response rate, which was 65.0% (95% confidence interval [CI], 48.3-78.9) at the end of induction treatment. The 2-year progression-free and overall survival rates were 67.1% (95% CI, 50.1-79.4) and 82.4% (95% CI, 66.5-91.2). The most common grades 3 and 4 hematologic adverse event (AE) was neutropenia (n = 14 [35.0%]). The most common grades 3 and 4 nonhematologic AEs were increased alanine transaminase (n = 5 [12.5%]) and aspartate transaminase levels (n = 5; 12.5%), and pulmonary infection (n = 5 [12.5%]). No events of atrial fibrillation were observed. Importantly, the efficacy of ZR2 was more dependent on tumor microenvironmental than genetic alterations, and was associated with upregulation of class I and II human leukocyte antigen and increased number and function of conventional type 1 dendritic cells. Preexisting expansion of intratumoral CD8+ T cells and treatment-induced clonal T-cell receptor (TCR) repertoire contributed to better clinical outcome. TCR sequencing of the peripheral blood mononuclear cell samples from patients with durable remission detected the expanded T-cell clones 3 years after treatment. These findings thus improve the understanding of the effect of T-cell immunological memory on ZR2-based immunotherapy, and support a paradigm shift toward mechanism-based targeted therapy of aggressive lymphoma. This trial was registered at www.clinicaltrials.gov as #NCT04460248.

Detection of KIT p.D816V is a cornerstone in the diagnosis and classification of mast cell activation syndromes (MCAS) and mastocytosis. However, KIT p.D816V may be undetected due to a low mutated-cell burden in the blood and bone marrow (BM) of many patients, particularly those without skin lesions. These findings underscore the need for ultrasensitive molecular techniques for the detection of KIT p.D816V in these clinical settings. Here, we evaluated, to our knowledge, for the first time, the sensitivity and specificity of a novel Flow-SuperRCA KIT p.D816V assay, compared with conventional allele-specific oligonucleotide quantitative polymerase chain reaction (ASOqPCR), through the analysis of 548 blood and BM samples from 337 adult patients with MCAS and mastocytosis. Our results demonstrated greater sensitivity of the new technique vs ASOqPCR (limit of detection: 0.001% vs 0.01% variant allele frequency), with higher rates of positivity for KIT p.D816V in whole blood and/or BM of 64% of patients with monoclonal MCAS and 55% of patients with BM mastocytosis (P < .0001). Notably, the sensitivity of the new assay went beyond that of ASOqPCR in purified BM mast cells (P < .0001). Additionally, clonality was newly identified in 18% of patients previously diagnosed with nonclonal MCAS, who presented with a unique cutaneous MCA-related symptomatic profile. These results confirm the high specificity and ultrasensitivity of the Flow-SuperRCA assay for the detection of KIT p.D816V, emerging as a well-suited whole-blood and whole-BM test for diagnostic screening and classification of patients with MCAS and mastocytosis. These findings further highlight the clonal nature of an unprecedently high fraction of patients who presented with anaphylaxis and MCAS, with important pathogenic, diagnostic, and clinical implications.

Blood clotting is triggered in hemostasis and thrombosis when the membrane-bound tissue factor (TF)/factor VIIa (FVIIa) complex activates factor X (FX). There are no structures of TF/FVIIa on membranes, with or without FX. Using cryoelectron microscopy (cryo-EM) to address this gap, we assembled TF/FVIIa complexes on nanoscale membrane bilayers (nanodiscs), bound to XK1 and an antibody fragment. XK1 is a FX mimetic whose protease domain is replaced by the first Kunitz-type (K1) domain of the TF pathway inhibitor, whereas 10H10 is a noninhibitory, anti-TF antibody. We determined a cryo-EM structure of a TF/FVIIa/XK1/10H10/nanodisc complex with a resolution of 3.7 Å, allowing us to model all the protein backbones. TF/FVIIa extends perpendicularly from the membrane, interacting with a "handle-shaped" XK1 at 2 locations: the K1 domain docks into FVIIa's active site, whereas the γ-carboxyglutamate-rich (GLA) domain binds to the TF substrate-binding exosite. The FX and FVIIa GLA domains also contact each other and the membrane surface. Except for a minor contact between the first epidermal growth factor (EGF)-like domain of XK1 and TF, the rest of the FX light chain does not interact with TF/FVIIa. The structure reveals a previously unrecognized, membrane-dependent allosteric activation mechanism between FVIIa and TF, in which a serine-rich loop in TF that partially obscures the TF exosite must undergo a shift to allow access of the FX GLA domain to its final binding location on the membrane-bound TF/FVIIa complex. This mechanism also provides a novel explanation for the otherwise puzzling phenomenon of TF encryption/decryption on cell surfaces.

Aberrant activation of BCL11B (BCL11B-a) defines a subtype of lineage-ambiguous leukemias with T-lymphoid and myeloid features, co-occurring activating FLT3 mutations, and a stem/progenitor immunophenotype and gene expression profile. Similar to other lineage-ambiguous leukemias, optimal treatment is unclear, and there are limited targeted therapeutic options. Here, we investigated the efficacy of B-cell lymphoma 2 (BCL-2) and FMS-like tyrosine kinase 3 (FLT3) inhibition with venetoclax and gilteritinib, respectively, in preclinical models of BCL11B-a leukemia. Despite variation in response to single-agent therapies, the combination of venetoclax plus gilteritinib (VenGilt) was highly effective in all models evaluated. BH3 profiling suggested that resistance to venetoclax monotherapy was due to the tumor-intrinsic dependence on additional BCL-2 family proteins before drug treatment. Longitudinal single-cell RNA sequencing analysis identified mitochondrial pathways and a pro-lymphoid gene expression signature as potential drivers of rare cell survival on VenGilt therapy. These data support clinical evaluation of venetoclax in combination with gilteritinib in BCL11B-a lineage-ambiguous leukemias.

Understanding the roles of myeloid cells in the tumor microenvironment (TME) has emerged as a promising strategy to identify novel targets to counteract the immunosuppressive barriers protecting multiple myeloma (MM). Neutrophils are a new cancer research focus due to their potential to reduce the efficacy of immune-based therapies. This study aimed to deepen understanding of neutrophil function in MM by analyzing freshly isolated myeloid cells from paired focal lesions (FLs) and bone marrow using single-cell RNA sequencing, immunofluorescence imaging, and functional assays. We describe 3 distinct CXCR2+ mature neutrophil subsets: TREM1+CD10+, RETN+LCN2+, and TNFAIP3+CXCL8+, each exhibiting unique phenotypes within the TME. Notably, the TREM1+CD10+ subset was highly prevalent, particularly in FLs, demonstrating potent immunosuppressive effects on T cells. This subset's gene signature was correlated with shorter overall survival (OS) in a large data set of patients with MM, underscoring its clinical significance. Targeted inhibition of neutrophil activity through CXCR2 blockade, alone or combined with standard anti-MM therapies, significantly reduced tumor burden, improving OS in preclinical MM models. These insights into neutrophil-mediated immunosuppression in MM provide valuable knowledge regarding mechanisms driving immune evasion, and reveal new therapeutic approaches to enhance the efficacy of MM treatment.

Hematopoietic stem cells (HSCs) exhibit a distinctive antioxidant profile during steady-state and stress hematopoiesis. HSCs and multipotential progenitors (MPPs) are metabolically coupled to bone marrow mesenchymal stromal cells through mitochondrial transfer, a process dependent on hematopoietic connexin 43 (Cx43) and low adenosine monophosphate-activated protein kinase (AMPK) activity. However, the mechanism by which Cx43 preserves mitochondrial functionality in HSCs remains elusive. Here, through integrated transcriptomic, proteomic, metabolomic, phenotypic, and functional analyses of HSCs and their isolated mitochondria, we identified that Cx43 is present on the inner and outer mitochondrial membranes of HSCs/MPPs, in which it primarily regulates mitochondrial metabolism and adenosine triphosphate synthesis by preserving the mitochondrial cristae, activation of mitochondrial AMPK, and 2-oxoglutarate dehydrogenase, a rate-liming enzyme in tricarboxylic acid cycle and electron transfer chain. During replicative stress, Cx43-deficient HSCs/MPPs fail to adapt metabolically and accumulate mitochondrial Ca2+, leading to increased mitochondrial AMPK activity, mitochondrial fission, mitophagy, and production of reactive oxygen species, thereby limiting HSC/MPP regeneration potential. Disruption of hyperfragmentation of mitochondria and mitophagy by Drp1 dominant-negative mutant (Drp1K38A) or restoration of mitochondrial function through ex vivo heteroplasmy prevents the harmful effects of Cx43 deficiency on mitochondrial metabolism and restore HSC activity in serial transplantation experiments. Re-expression analysis of Cx43 structure-function mutants indicates that Cx43 hemichannels are sufficient to reset HSC mitochondrial metabolism, dynamics, Ca2+ levels, and regeneration capacity. This report defines the cell-autonomous mechanism of action behind the role of Cx43 in HSC activity and opens a venue to translational applications in transplantation.

The current approach to minimize transplant-associated complications, including graft-versus-host disease (GVHD) includes long-term pharmacological immune suppression frequently accompanied by unwanted side effects. Advances in targeted immunotherapies regulating alloantigen responses in the recipient continue to reduce the need for pan-immunosuppression. Here, in vivo targeting of the tumor necrosis factor superfamily receptor TNFRSF25 (also known as DR3) and the high-affinity interleukin-2 (IL-2) receptor with a TL1A-immunoglobulin (TL1A-Ig) fusion protein and low-dose IL-2, respectively, was used to pretreat recipient mice before allogeneic hematopoietic stem cell transplantation (aHSCT). Pretreatment induced regulatory T cell (Treg) expansion persisting 1 to 2 weeks after HSCT, leading to diminished GVHD and improved transplant outcomes. Expansion was accompanied by an increase in the frequency of stable and active Tregs, creating a suppressive tissue environment in the colon, liver, and eye. Importantly, pretreatment supported epithelial cell function/integrity, a diverse microbiome including reduction of pathologic bacteria outgrowth, and promotion of butyrate producing bacteria, while maintaining physiologic levels of obligate/facultative anaerobes. Notably, using a sphingosine 1-phosphate receptor agonist to sequester T cells in lymphoid tissues, it was found that the increased tissue Treg frequency included resident CD69+CD103+FoxP3+ hepatic Tregs. In contrast to infusion of donor Tregs, the strategy developed here resulted in the presence of immunosuppressive target tissue environments in the recipient before the receipt of donor allogeneic-reactive T cells and successful perseveration of graft-versus-leukemia responses. We posit strategies that circumvent the need of producing large numbers of ex vivo manipulated Tregs may be accomplished through in vivo recipient Treg expansion, providing translational approaches to improve aHSCT outcomes.

T-cell engagers (TCEs) are transformative therapeutics in hematologic malignancies, including non-Hodgkin lymphoma. Initially approved for relapsed/refractory disease settings, TCEs are now explored in first-line and second-line settings, often combined with standard-of-care (SOC) treatments, including chemotherapy and antibody-drug conjugates. This study investigates glofitamab (CD20×CD3 TCE) combinations in preclinical humanized lymphoma models, addressing heterogeneity of tumor antigen expression, immune evasion, and T-cell exhaustion. Combining glofitamab with R-CHP-Pola (rituximab, cyclophosphamide, doxorubicin, prednisone, and polatuzumab vedotin) chemotherapy or Pola demonstrated strong synergistic antitumor efficacy with rapid tumor regression and reduced tumor cell proliferation. Glofitamab combination with gemcitabine/oxaliplatin also demonstrated strong efficacy, enhancing intratumor T-cell number, activation, and reduced exhaustion. These combinations were particularly advantageous in models with low and heterogeneous CD20 expression, facilitating rapid tumor debulking and elimination of CD20-low/CD20- cells. Translational studies with patient-derived peripheral blood mononuclear cells receiving glofitamab combination with chemotherapies demonstrated sustained T-cell functionality throughout extended treatment cycles. Novel chemotherapy-free combinations, including CD19-targeted 4-1BBL and CD19-CD28, amplified glofitamab activity, especially in CD20 high- and homogenous-expressing tumor models, with dual costimulatory approaches revealing synergy. In addition, the combination with checkpoint inhibitors (programmed cell death protein 1/Lag3-bispecific antibody) and regulatory T-cell depletion (α-CD25) emerged as promising approaches for enhanced efficacy and to sustain T-cell functionality. These findings highlight the versatility of glofitamab when integrated with SOC and innovative combinations, addressing resistance and improving patient outcomes. The preclinical investigations provide a strong foundation for ongoing and future clinical trials, emphasizing the need to tailor TCE-based combination therapies to maximize efficacy while minimizing toxicity in lymphoma treatment. These trials were registered at www.clinicaltrials.gov as #NCT04408638 and NCT03467373.

Dysregulated RNA modifications contribute to cancer progression and therapy resistance, yet the underlying mechanism often remains unknown. Here, we perform CRISPR-based synthetic lethality screens to systematically explore the role of RNA modifications in mediating resistance to antileukemic drugs. We identify the tRNA methyltransferase 5 (TRMT5)-mediated formation of N1-methylguanosine (m1G) in the transfer RNA (tRNA) anticodon loop as essential for mediating drug tolerance to cytarabine and venetoclax (Ven) in acute myeloid leukemia (AML). TRMT5 methylates nearly all mitochondrial and nuclear tRNAs with a guanosine at position 37, but its role in promoting drug tolerance specifically depends on its mitochondrial function. TRMT5 is essential for the dynamic upregulation of mitochondrial messenger RNA translation and oxidative phosphorylation, which are critical for sustaining drug tolerance in leukemia cells. This mitochondrial dependency correlates with therapy outcomes in patients with leukemia: lower expression of electron transport chain genes is linked to poorer outcomes in a cohort of nearly 100 patients with AML undergoing first induction therapy. Finally, we demonstrate that targeted depletion of the TRMT5 protein using a conditional degron, in conjunction with cytarabine and Ven treatment, synergistically induces cell death in drug-tolerant AML cells. Thus, our study reveals TRMT5 as a promising drug target for therapy-resistant leukemia.

Chronic active Epstein-Barr virus (EBV) infection (CAEBV) is an orphan disease characterized by the proliferation and infiltration of EBV-infected T/natural killer (NK) cells into multiple organs. Although CAEBV is a heterogeneous disease with diverse clinical courses, its pathogenesis remains poorly understood. In this study, we explored the molecular mechanisms underlying CAEBV by performing a comprehensive multiomics analysis, including genome, transcriptome, epigenome, and single-cell transcriptome and surface proteome analyses, of 65 patients with CAEBV. Methylation analysis identified 2 distinct subtypes of NK cell-type CAEBV based on the CpG island methylator phenotype (CIMP). In CIMP-positive CAEBV, regions associated with enhancer of zeste homolog 2 binding sites and histone H3 lysine 27 trimethylation exhibited increased DNA hypermethylation, resulting in downregulation of tumor suppressor and antiherpesvirus genes. CIMP-positive CAEBV had a particularly poor prognosis and displayed a "neoplastic" phenotype with a DNA methylation pattern similar to that of extranodal NK/T-cell lymphoma, a higher tumor mutation burden, and frequent copy number alterations. In addition, both in vitro and in vivo functional assays demonstrated that 5-azacytidine, a hypomethylating agent, was a potentially effective agent for high-risk CIMP-positive CAEBV. Finally, we established a method to effectively detect EBV-infected cells in single-cell analysis, suggesting that EBV-infected NK cells have tissue-resident properties and that innate and adaptive immunity to EBV is compromised in patients with CAEBV. The present findings provide insight into the complex molecular features of CAEBV and suggest potential molecular therapies.

With up to 10 years of follow-up, we report results from the final analysis of RESONATE- 2, a phase 3 study of first-line ibrutinib vs chlorambucil for the treatment of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). Patients aged ≥65 years with previously untreated CLL/SLL without del(17p) were randomly assigned to receive either single-agent ibrutinib (420 mg/d; n = 136) or chlorambucil (0.5-0.8 mg/kg; ≤12 cycles; n = 133). With a median follow-up of 9.6 years in the ibrutinib arm, the median progression-free survival (PFS) was 8.9 years (95% confidence interval [CI], 7.0 to not estimable [NE]) vs 1.3 years (95% CI, 0.9-1.6) for the chlorambucil arm. Among patients with unmutated immunoglobulin heavy chain variable (uIGHV), del (11q), mutated TP53, or complex karyotype, the median PFS was 8.4 years (95% CI, 6.8 to NE) with ibrutinib and 0.7 years (95% CI, 0.4-1.2) with chlorambucil. Median overall survival (OS) with ibrutinib was not reached. The most common adverse events (AEs) of any grade included diarrhea (52%), fatigue (41%), cough (39%), nausea (32%), arthralgia (31%), peripheral edema (31%), and hypertension (30%). During the entire study period, 34 of 136 patients (25%) had an ibrutinib dose reduction due to AEs; these AEs improved in 30 of 34 patients (88%). At study completion, 27% of patients remained on first-line ibrutinib treatment. This landmark RESONATE-2 study defines median PFS and demonstrates continued OS benefit of first-line ibrutinib treatment for patients with CLL/SLL, including those with high-risk genomic features. Sustained efficacy and tolerability of ibrutinib reemphasize the favorable benefit-risk profile. This trial was registered at www.ClinicalTrials.gov as NCT01722487/NCT01724346.

Attempting to induce a complete remission before allogeneic hematopoietic cell transplant (alloHCT) is current practice in patients with acute myeloid leukemia (AML). However, benefit of remission induction strategy (RIST) before alloHCT has never been proven in a prospective trial. Potent conditioning regimens exist that allow for successful alloHCT in patients with active AML. Therefore, the ASAP trial was conducted to test RIST by salvage chemotherapy before alloHCT against immediate transplant after intensified conditioning. In total, 281 patients with AML with poor response after first induction or untreated first relapse were randomized 1:1 to RIST with high-dose cytarabine plus mitoxantrone vs immediate alloHCT with sequential conditioning after nonintensive disease control (DisC) measures, preferentially watchful waiting only. Overall survival at 5 years from randomization analyzed according to intention-to-treat was 46.1% for DisC vs 47.5% for RIST (P = .82). In multivariable Cox regression analysis, genetic AML risk according to European LeukemiaNet criteria (P < .0001), age (P = .001), and comorbidities (P = .046) predicted survival, but not treatment arm (hazard ratio, 1.08 for DisC vs RIST; P = .67). In conclusion, long-term follow-up of the ASAP trial showed no survival advantage for standard salvage chemotherapy before alloHCT as opposed to immediate alloHCT. The trial results question the general concept of RIST with intensive standard salvage therapy before alloHCT for all patients, because immediate alloHCT may reduce time in hospital and health care expenses. Novel bridging therapies that are well tolerated, and posttransplant maintenance with targeted drugs are urgently warranted, especially for adverse-risk AML, to improve outcomes after alloHCT. This trial was registered at www.ClinicalTrials.gov as #NCT02461537.