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.

Recent clinical trials in both transplant-eligible and -ineligible newly diagnosed multiple myeloma using 3- and 4-drug combinations have demonstrated unprecedented levels of response. However, 2 recently published studies redefining high risk in newly diagnosed multiple myeloma in the context of these newer and more effective treatments demonstrate that a significant minority of patients likely derive little benefit from these newer approaches. These new prognostic systems thus provide an evidence-based framework for the development of much-needed risk-stratified clinical trials.

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.

TP53-mutated myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) are among the most aggressive and chemotherapy-refractory myeloid neoplasms, with a median overall survival of <6 months. An enormous unmet need exists to develop novel therapeutic strategies, and understand resistance mechanisms to suboptimal existing therapies for this disease. In 2 parallel, phase 2 clinical trials that combined eprenetapopt with azacitidine in TP53-mutated MDS/AML, we observed complete remission rates of 40% to 50%, and molecular remission rates of 38%. However, unless allogeneic stem cell transplant was performed, relapse inevitably occurred. To understand the mechanisms of secondary resistance responsible for this, we genotyped sequential clinical trial samples, conducted a genome-wide CRISPR screen in TP53-mutated leukemia cells, and identified XPO1 as a therapeutically tractable mediator of resistance. We demonstrate that XPO1 is overexpressed in patient samples after eprenetapopt and azacitidine treatment, elucidate the mechanism by which this occurs, and determine that it is necessary and sufficient for resistance to combination therapy. Finally, we validate in a variety of model systems, including a novel patient-derived xenograft model of TP53 mutant MDS, that eprenetapopt in combination with XPO1 inhibitors can overcome this resistance, providing preclinical rationale that this novel combination strategy is a viable therapeutic approach in patients with TP53 mutant MDS/AML.

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.

JAK2V617F is one of the most common mutations in clonal hematopoiesis of indeterminate potential (CHIP) and a major driver of myeloproliferative neoplasms (MPNs). To determine the impact of a low-frequency JAK2V617F clone on both the hematopoietic system and the bone marrow (BM) stroma, we developed a traceable murine MPN model, in which whole BM transplantation (BMT) was performed using CD45.2 5.0 × 106 JAK2V617F donor cells transplanted into unconditioned CD45.1 recipient mice. BMT recipients developed a polycythemia vera-like phenotype (elevated hematocrit and leukocytosis) with a 2.7% average donor cell chimerism in peripheral blood. Eight months after BMT, RNA sequencing (RNA-seq) analysis of BM cells sorted according to CD45.1/CD45.2 expression showed significant upregulation of early erythroblast- and myeloid cell-specific transcripts, and downregulation of lymphoid transcripts in donor-derived cells compared to controls. Surprisingly, recipient-derived cells also showed upregulation of myeloid- and erythroblast-related transcripts, indicating a skewing of the non-JAK2V617F-carrying recipient hematopoietic system toward an MPN-like phenotype. In addition, RNA-seq analysis of the BM stroma from JAK2V617F BMT recipients indicated significant loss of osteomesenchymal transcripts. Consistently, micro-computed tomography imaging indicated loss of trabecular bone. In sum, our results indicate that low-frequency MPN-driving cells in unconditioned recipients not only impact hematopoiesis-supporting stroma but also profoundly influence unmutated cells, uniquely altering their transcriptomic and phenotypic profiles. These observations are challenging our current understanding of the etiology and therapeutic approaches to MPNs and other CHIP-associated diseases.

TP53 mutations are found in 10% to 15% of myeloid neoplasms and are one of its most important prognostic factors. Emerging data show that TP53 mutational allele status is a key determinant of clinical outcomes, with multihit TP53 mutant myeloid neoplasms having a very poor prognosis. Significant differences exist among the methods used in clinical and research settings to assess TP53 mutational status, leading to variability in reported patient characteristics, response to therapy, and survival. Indeed, differences in the criteria used to define TP53 mutational states among professional societies and in landmark research studies have led to confusion, suboptimal clinical testing, and variability in therapy recommendations. We review the methods used to assess for TP53 mutational allele status and provide recommendations, based on clinically available testing, for the accurate evaluation of TP53 gene mutations in myeloid neoplasms. Hotspot mutations represent ∼35% of all TP53 missense mutations in myeloid neoplasms. There is evidence that these hotspot mutations may have dominant-negative or gain-of-function properties. Here, we review this evidence and discuss the potential impact of TP53 mutation identity on patient outcomes and clinical management.

The treatment landscape for chronic lymphocytic leukemia (CLL) has been transformed by the advent of covalent Bruton tyrosine kinase (BTK) inhibitors (cBTKis) and B-cell lymphoma 2 (BCL-2) inhibitors, leading to markedly improved outcomes and, for many, near-normal life expectancy. However, patients progressing after both classes of therapy (double-refractory) have limited options and poor prognoses. This review outlines a practical approach to managing double-exposed or double-refractory CLL, incorporating clinical cases, trial data, and expert perspectives. For cBTKi intolerance, second-generation agents may remain effective. Venetoclax retreatment is reasonable after prior fixed-duration use. In true double-refractory disease, noncovalent BTK inhibitors (eg, pirtobrutinib) and CD19-directed chimeric antigen receptor T-cell (CAR-T) therapy (lisocabtagene maraleucel) are standard-of-care options. Pirtobrutinib induces rapid responses, though often of limited duration, underscoring the need for early consolidation planning with CAR-T or allogeneic stem cell transplant. Persistent disease after CAR-T therapy warrants close monitoring and timely transplant referral in eligible patients. Phosphoinositide 3-kinase inhibitors remain available but are limited by toxicity and modest benefit. Emerging agents, including BTK degraders, bispecific antibodies, and novel cellular therapies, offer promising future directions. Optimizing outcomes in double-refractory CLL requires an individualized, nuanced strategy integrating available treatments with innovative approaches under investigation.