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•The major cause of death in patients with ataxia-telangiectasia and hematological malignancies is treatment-related toxicity.•The germ line ATMpathogenic variant functional class is a robust outcome predictor, which can be applied to therapy stratification.

•Higher gut microbiota diversity before transplantation correlates with better overall survival and lower acute GVHD incidence.•In pediatric patients, higher pretransplant diversity is associated with higher abundance of short-chain fatty acid–producing taxa.

•The novel combination of tafasitamab ± lenalidomide + R-CHOP showed signs of efficacy in patients with untreated DLBCL, with no new safety signals.•The results, including a post hoc analysis in patients with high-risk disease (IPI 3-5), support the ongoing phase 3 frontMIND trial.

Recirculation of chronic lymphocytic leukemia (CLL) cells between the peripheral blood and lymphoid niches plays a critical role in disease pathophysiology, and inhibiting this process is one of the major mechanisms of action for B-cell receptor (BCR) inhibitors such as ibrutinib and idelalisib. Migration is a complex process guided by chemokine receptors and integrins. However, it remains largely unknown how CLL cells integrate multiple migratory signals while balancing survival in the peripheral blood and the decision to return to immune niches. Our study provided evidence that CXCR4/CD5 intraclonal subpopulations can be used to study the regulation of migration of CLL cells. We performed RNA profiling of CXCR4dimCD5bright vs CXCR4brightCD5dim CLL cells and identified differential expression of dozens of molecules with a putative function in cell migration. GRB2–associated binding protein 1 (GAB1) positively regulated CLL cell homing capacity of CXCR4brightCD5dim cells. Gradual GAB1 accumulation in CLL cells outside immune niches was mediated by FoxO1-induced transcriptional GAB1 activation. Upregulation of GAB1 also played an important role in maintaining basal phosphatidylinositol 3-kinase (PI3K) activity and the “tonic” AKT phosphorylation required to sustain the survival of resting CLL B cells. This finding is important during ibrutinib therapy, because CLL cells induce the FoxO1-GAB1-pAKT axis, which represents an adaptation mechanism to the inability to home to immune niches. We have demonstrated that GAB1 can be targeted therapeutically by novel GAB1 inhibitors, alone or in combination with BTK inhibition. GAB1 inhibitors induce CLL cell apoptosis, impair cell migration, inhibit tonic or BCR-induced AKT phosphorylation, and block compensatory AKT activity during ibrutinib therapy.

Sutimlimab, a first-in-class humanized immunoglobulin G4 (IgG4) monoclonal antibody that selectively inhibits the classical complement pathway at C1s, rapidly halted hemolysis in the single-arm CARDINAL study in recently transfused patients with cold agglutinin disease (CAD). CADENZA was a 26-week randomized, placebo-controlled phase 3 study to assess safety and efficacy of sutimlimab in patients with CAD without recent (within 6 months prior to enrollment) transfusion history. Forty-two patients with screening hemoglobin ≤10 g/dL, elevated bilirubin, and ≥1 CAD symptom received sutimlimab (n = 22) or placebo (n = 20) on days 0 and 7 and then biweekly. Composite primary endpoint criteria (hemoglobin increase ≥1.5 g/dL at treatment assessment timepoint [mean of weeks 23, 25, 26], avoidance of transfusion, and study-prohibited CAD therapy [weeks 5-26]) were met by 16 patients (73%) on sutimlimab, and 3 patients (15%) on placebo (odds ratio, 15.9 [95% confidence interval, 2.9, 88.0; P < .001]). Sutimlimab, but not placebo, significantly increased mean hemoglobin and FACIT-Fatigue scores at treatment assessment timepoint. Sutimlimab normalized mean bilirubin by week 1. Improvements correlated with near-complete inhibition of the classical complement pathway (2.3% mean activity at week 1) and C4 normalization. Twenty-one (96%) sutimlimab patients and 20 (100%) placebo patients experienced ≥1 treatment-emergent adverse event. Headache, hypertension, rhinitis, Raynaud phenomenon, and acrocyanosis were more frequent with sutimlimab vs placebo, with a difference of ≥3 patients between groups. Three sutimlimab patients discontinued owing to adverse events; no placebo patients discontinued. These data demonstrate that sutimlimab has potential to be an important advancement in the treatment of CAD. This trial was registered at www.clinicaltrials.gov as #NCT03347422.

B-cell receptor (BCR) signaling and T-cell interactions play a pivotal role in chronic lymphocytic leukemia (CLL) pathogenesis and disease aggressiveness. CLL cells can use microRNAs (miRNAs) and their targets to modulate microenvironmental interactions in the lymph node niches. To identify miRNA expression changes in the CLL microenvironment, we performed complex profiling of short noncoding RNAs in this context by comparing CXCR4/CD5 intraclonal cell subpopulations (CXCR4dimCD5bright vs CXCR4brightCD5dim cells). This identified dozens of differentially expressed miRNAs, including several that have previously been shown to modulate BCR signaling (miR-155, miR-150, and miR-22) but also other candidates for a role in microenvironmental interactions. Notably, all 3 miR-29 family members (miR-29a, miR-29b, miR-29c) were consistently down-modulated in the immune niches, and lower miR-29(a/b/c) levels associated with an increased relative responsiveness of CLL cells to BCR ligation and significantly shorter overall survival of CLL patients. We identified tumor necrosis factor receptor–associated factor 4 (TRAF4) as a novel direct target of miR-29s and revealed that higher TRAF4 levels increase CLL responsiveness to CD40 activation and downstream nuclear factor-κB (NF-κB) signaling. In CLL, BCR represses miR-29 expression via MYC, allowing for concurrent TRAF4 upregulation and stronger CD40–NF-κB signaling. This regulatory loop is disrupted by BCR inhibitors (bruton tyrosine kinase [BTK] inhibitor ibrutinib or phosphatidylinositol 3-kinase [PI3K] inhibitor idelalisib). In summary, we showed for the first time that a miRNA-dependent mechanism acts to activate CD40 signaling/T-cell interactions in a CLL microenvironment and described a novel miR-29–TRAF4–CD40 signaling axis modulated by BCR activity.

B-cell receptor (BCR) signaling and T-cell interactions play a pivotal role in chronic lymphocytic leukemia (CLL) pathogenesis and disease aggressiveness. CLL cells can use microRNAs (miRNAs) and their targets to modulate microenvironmental interactions in the lymph node niches. To identify miRNA expression changes in the CLL microenvironment, we performed complex profiling of short noncoding RNAs in this context by comparing CXCR4/CD5 intraclonal cell subpopulations (CXCR4dimCD5brightvs CXCR4brightCD5dimcells). This identified dozens of differentially expressed miRNAs, including several that have previously been shown to modulate BCR signaling (miR-155, miR-150, and miR-22) but also other candidates for a role in microenvironmental interactions. Notably, all 3 miR-29family members (miR-29a, miR-29b, miR-29c) were consistently down-modulated in the immune niches, and lower miR-29(a/b/c)levels associated with an increased relative responsiveness of CLL cells to BCR ligation and significantly shorter overall survival of CLL patients. We identified tumor necrosis factor receptor–associated factor 4 (TRAF4) as a novel direct target of miR-29sand revealed that higher TRAF4 levels increase CLL responsiveness to CD40 activation and downstream nuclear factor-κB (NF-κB) signaling. In CLL, BCR represses miR-29expression via MYC, allowing for concurrent TRAF4 upregulation and stronger CD40–NF-κB signaling. This regulatory loop is disrupted by BCR inhibitors (bruton tyrosine kinase [BTK] inhibitor ibrutinib or phosphatidylinositol 3-kinase [PI3K] inhibitor idelalisib). In summary, we showed for the first time that a miRNA-dependent mechanism acts to activate CD40 signaling/T-cell interactions in a CLL microenvironment and described a novel miR-29–TRAF4–CD40 signaling axis modulated by BCR activity.

Genetic alterations in the DNA damage response (DDR) pathway are a frequent mechanism of resistance to chemoimmunotherapy (CIT) in B-cell malignancies. We have previously shown that the synergy of CIT relies on secretory crosstalk elicited by chemotherapy between the tumor cells and macrophages. Here, we show that loss of multiple different members of the DDR pathway inhibits macrophage phagocytic capacity in vitro and in vivo. Particularly, loss of TP53 led to decreased phagocytic capacity ex vivo across multiple B-cell malignancies. We demonstrate via in vivo cyclophosphamide treatment using the Eμ-TCL1 mouse model that loss of macrophage phagocytic capacity in Tp53-deleted leukemia is driven by a significant downregulation of a phagocytic transcriptomic signature using small conditional RNA sequencing. By analyzing the tumor B-cell proteome, we identified a TP53-specific upregulation of proteins associated with extracellular vesicles (EVs). We abrogated EV biogenesis in tumor B-cells via clustered regularly interspaced short palindromic repeats (CRISPR)-knockout (KO) of RAB27A and confirmed that the EVs from TP53-deleted lymphoma cells were responsible for the reduced phagocytic capacity and the in vivo CIT resistance. Furthermore, we observed that TP53 loss led to an upregulation of both PD-L1 cell surface expression and secretion of EVs by lymphoma cells. Disruption of EV bound PD-L1 by anti–PD-L1 antibodies or PD-L1 CRISPR-KO improved macrophage phagocytic capacity and in vivo therapy response. Thus, we demonstrate enhanced EV release and increased PD-L1 expression in TP53-deficient B-cell lymphomas as novel mechanisms of macrophage function alteration in CIT resistance. This study indicates the use of checkpoint inhibition in the combination treatment of B-cell malignancies with TP53 loss.

Richter’s transformation (RT) is an aggressive lymphoma that occurs upon progression from chronic lymphocytic leukemia (CLL). Transformation has been associated with genetic aberrations in the CLL phase involving TP53, CDKN2A, MYC, and NOTCH1; however, a significant proportion of RT cases lack CLL phase–associated events. Here, we report that high levels of AKT phosphorylation occur both in high-risk CLL patients harboring TP53 and NOTCH1 mutations as well as in patients with RT. Genetic overactivation of Akt in the murine Eµ-TCL1 CLL mouse model resulted in CLL transformation to RT with significantly reduced survival and an aggressive lymphoma phenotype. In the absence of recurrent mutations, we identified a profile of genomic aberrations intermediate between CLL and diffuse large B-cell lymphoma. Multiomics assessment by phosphoproteomic/proteomic and single-cell transcriptomic profiles of this Akt-induced murine RT revealed an S100 protein-defined subcluster of highly aggressive lymphoma cells that developed from CLL cells, through activation of Notch via Notch ligand expressed by T cells. Constitutively active Notch1 similarly induced RT of murine CLL. We identify Akt activation as an initiator of CLL transformation toward aggressive lymphoma by inducing Notch signaling between RT cells and microenvironmental T cells.

The phase 2 CAVALLI (NCT02055820) study assessed efficacy and safety of venetoclax, a selective B-cell lymphoma-2 (Bcl-2) inhibitor, with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) in first-line (1L) diffuse large B-cell lymphoma (DLBCL), including patients demonstrating Bcl-2 protein overexpression by immunohistochemistry (Bcl-2 IHC+). Eligible patients were ≥18 years of age and had previously untreated DLBCL, Eastern Cooperative Oncology Group performance status ≤2, and International Prognostic Index 2 to 5. Venetoclax 800 mg (days 4-10, cycle 1; days 1-10, cycles 2-8) was administered with rituximab (8 cycles) and cyclophosphamide, doxorubicin, vincristine, and prednisone (6-8 cycles) in 21-day cycles. Primary end points were safety, tolerability, and complete response (CR) at end of treatment (EOT). Secondary end points were progression-free survival (PFS) and overall survival. Comparative analyses used covariate-adjusted R-CHOP controls from the GOYA/BO21005 study, an appropriate contemporary benchmark for safety and efficacy. Safety and efficacy analyses included 206 patients. CR rate at EOT was 69% in the overall population and was maintained across Bcl-2 IHC+ subgroups. With a median follow-up of 32.2 months, trends were observed for improved investigator-assessed PFS for venetoclax plus R-CHOP in the overall population (hazard ratio [HR], 0.61; 95% confidence interval [CI], 0.43-0.87) and Bcl-2 IHC+ subgroups (HR, 0.55; 95% CI, 0.34-0.89) vs R-CHOP. Despite a higher incidence of grade 3/4 hematologic adverse events (86%), related mortality was not increased (2%). Chemotherapy dose intensity was similar in CAVALLI vs GOYA. The addition of venetoclax to R-CHOP in 1L DLBCL demonstrates increased, but manageable, myelosuppression and the potential of improved efficacy, particularly in high-risk Bcl-2 IHC+ patient subgroups.

Mastocytosis is a hematopoietic neoplasm characterized by expansion of KITD816V-mutated clonal mast cells in various organs and severe or even life-threatening anaphylactic reactions. Recently, hereditary α-tryptasemia (HαT) has been described as a common genetic trait with increased copy numbers of the α-tryptase encoding gene, TPSAB1, and associated with an increased basal serum tryptase level and a risk of mast cell activation. The purpose of our study was to elucidate the clinical relevance of HαT in patients with mastocytosis. TPSAB1germline copy number variants were assessed by digital polymerase chain reaction in 180 mastocytosis patients, 180 sex-matched control subjects, 720 patients with other myeloid neoplasms, and 61 additional mastocytosis patients of an independent validation cohort. α-Tryptase encoding TPSAB1copy number gains, compatible with HαT, were identified in 17.2% of mastocytosis patients and 4.4% of the control population (P< .001). Patients with HαT exhibited higher tryptase levels than patients without HαT (median tryptase in HαT+cases: 49.6 ng/mL vs HαT−cases: 34.5 ng/mL, P= .004) independent of the mast cell burden. Hymenoptera venom hypersensitivity reactions and severe cardiovascular mediator-related symptoms/anaphylaxis were by far more frequently observed in mastocytosis patients with HαT than in those without HαT. Results were confirmed in an independent validation cohort. The high prevalence of HαT in mastocytosis hints at a potential pathogenic role of germline α-tryptase encoding TPSAB1copy number gains in disease evolution. Together, our data suggest that HαT is a novel emerging robust biomarker in mastocytosis that is useful for determining the individual patient´s risk of developing severe anaphylaxis.

Bruton tyrosine kinase (BTK) inhibition is an effective treatment approach for patients with Waldenström macroglobulinemia (WM). The phase 3 ASPEN study compared the efficacy and safety of ibrutinib, a first-generation BTK inhibitor, with zanubrutinib, a novel highly selective BTK inhibitor, in patients with WM. Patients with MYD88L265P disease were randomly assigned 1:1 to treatment with ibrutinib or zanubrutinib. The primary end point was the proportion of patients achieving a complete response (CR) or a very good partial response (VGPR) by independent review. Key secondary end points included major response rate (MRR), progression-free survival (PFS), duration of response (DOR), disease burden, and safety. A total of 201 patients were randomized, and 199 received ≥1 dose of study treatment. No patient achieved a CR. Twenty-nine (28%) zanubrutinib patients and 19 (19%) ibrutinib patients achieved a VGPR, a nonstatistically significant difference (P = .09). MRRs were 77% and 78%, respectively. Median DOR and PFS were not reached; 84% and 85% of ibrutinib and zanubrutinib patients were progression free at 18 months. Atrial fibrillation, contusion, diarrhea, peripheral edema, hemorrhage, muscle spasms, and pneumonia, as well as adverse events leading to treatment discontinuation, were less common among zanubrutinib recipients. Incidence of neutropenia was higher with zanubrutinib, although grade ≥3 infection rates were similar in both arms (1.2 and 1.1 events per 100 person-months). These results demonstrate that zanubrutinib and ibrutinib are highly effective in the treatment of WM, but zanubrutinib treatment was associated with a trend toward better response quality and less toxicity, particularly cardiovascular toxicity.

Follicular lymphoma (FL) is a common indolent B-cell malignancy with a variable clinical course. An unfavorable event in its course is histological transformation to a high-grade lymphoma, typically diffuse large B-cell lymphoma. Recent studies show that genetic aberrations of MYC or its overexpression are associated with FL transformation (tFL). However, the precise molecular mechanisms underlying tFL are unclear. Here we performed the first profiling of expression of microRNAs (miRNAs) in paired samples of FL and tFL and identified 5 miRNAs as being differentially expressed. We focused on one of these miRNAs, namely miR-150, which was uniformly downmodulated in all examined tFLs (∼3.5-fold), and observed that high levels of MYC are responsible for repressing miR-150 in tFL by binding in its upstream region. This MYC-mediated repression of miR-150 in B cells is not dependent on LIN28A/B proteins, which influence the maturation of miR-150 precursor (pri-miR-150) in myeloid cells. We also demonstrated that low miR-150 levels in tFL lead to upregulation of its target, namely FOXP1 protein, which is a known positive regulator of cell survival, as well as B-cell receptor and NF-κB signaling in malignant B cells. We revealed that low levels of miR-150 and high levels of its target, FOXP1, are associated with shorter overall survival in FL and suggest that miR-150 could serve as a good biomarker measurable in formalin-fixed paraffin-embedded tissue. Overall, our study demonstrates the role of the MYC/miR-150/FOXP1 axis in malignant B cells as a determinant of FL aggressiveness and its high-grade transformation.

Follicular lymphoma (FL) is a common indolent B-cell malignancy with a variable clinical course. An unfavorable event in its course is histological transformation to a high-grade lymphoma, typically diffuse large B-cell lymphoma. Recent studies show that genetic aberrations of MYCor its overexpression are associated with FL transformation (tFL). However, the precise molecular mechanisms underlying tFL are unclear. Here we performed the first profiling of expression of microRNAs (miRNAs) in paired samples of FL and tFL and identified 5 miRNAs as being differentially expressed. We focused on one of these miRNAs, namely miR-150, which was uniformly downmodulated in all examined tFLs (∼3.5-fold), and observed that high levels of MYC are responsible for repressing miR-150in tFL by binding in its upstream region. This MYC-mediated repression of miR-150in B cells is not dependent on LIN28A/B proteins, which influence the maturation of miR-150precursor (pri-miR-150) in myeloid cells. We also demonstrated that low miR-150levels in tFL lead to upregulation of its target, namely FOXP1 protein, which is a known positive regulator of cell survival, as well as B-cell receptor and NF-κB signaling in malignant B cells. We revealed that low levels of miR-150and high levels of its target, FOXP1, are associated with shorter overall survival in FL and suggest that miR-150could serve as a good biomarker measurable in formalin-fixed paraffin-embedded tissue. Overall, our study demonstrates the role of the MYC/miR-150/FOXP1 axis in malignant B cells as a determinant of FL aggressiveness and its high-grade transformation.

Central nervous system (CNS) relapse carries a poor prognosis in diffuse large B-cell lymphoma (DLBCL). Integrating biomarkers into the CNS–International Prognostic Index (CNS-IPI) risk model may improve identification of patients at high risk for developing secondary CNS disease. CNS relapse was analyzed in 1418 DLBCL patients treated with obinutuzumab or rituximab plus cyclophosphamide, doxorubicin, vincristine, prednisone chemotherapy in the phase 3 GOYA study. Cell of origin (COO) was assessed using gene-expression profiling. BCL2 and MYC protein expression was analyzed by immunohistochemistry. The impact of CNS-IPI, COO, and BCL2/MYC dual-expression status on CNS relapse was assessed using a multivariate Cox regression model (data available in n = 1418, n = 933, and n = 688, respectively). High CNS-IPI score (hazard ratio [HR], 4.0; 95% confidence interval [CI], 1.3-12.3; P = .02) and activated B-cell?like (ABC) (HR, 5.2; 95% CI, 2.1-12.9; P = .0004) or unclassified COO subtypes (HR, 4.2; 95% CI, 1.5-11.7; P = .006) were independently associated with CNS relapse. BCL2/MYC dual-expression status did not impact CNS relapse risk. Three risk subgroups were identified based on the presence of high CNS-IPI score and/or ABC/unclassified COO (CNS-IPI-C model): low risk (no risk factors, n = 450 [48.2%]), intermediate risk (1 factor, n = 408 [43.7%]), and high risk (both factors, n = 75 [8.0%]). Two-year CNS relapse rates were 0.5%, 4.4%, and 15.2% in the respective risk subgroups. Combining high CNS-IPI and ABC/unclassified COO improved CNS relapse prediction and identified a patient subgroup at high risk for developing CNS relapse. The study was registered at www.clinicaltrials.gov as #NCT01287741.

Background:Ibrutinib (Ibr) is a once-daily Bruton tyrosine kinase (BTK) inhibitor approved in multiple regions for patients (pts) with mantle cell lymphoma (MCL) who have received ≥1 prior therapy. Venetoclax (Ven) is a BCL-2 inhibitor approved in the US for pts with chronic lymphocytic leukemia and previously untreated acute myeloid leukemia. Ibr and Ven have distinct and complementary modes of action, and the combination has shown promising clinical activity in early phase studies in MCL (Tam, N Engl J Med2018; Wang, J Hematol Oncol2021). Here, we report the primary analysis results from the multinational, randomized, double-blind, phase 3 SYMPATICO (NCT03112174) study comparing Ibr+Ven vs Ibr + placebo (Pbo) in pts with relapsed/refractory (R/R) MCL.

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Background:Patients with relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) who fail or are ineligible for autologous stem cell transplant (ASCT) have poor outcomes with standard chemotherapy, and novel, effective therapeutic options are needed. A retrospective analysis showed that treatment with rituximab and gemcitabine + oxaliplatin (GemOx) in a transplant-ineligible population resulted in a complete response rate of 33% in the overall population; among patients refractory to previous therapy, 10% achieved complete response (Cazelles et al, Leuk Lymphoma2021). Epcoritamab, a subcutaneously administered (SC) CD3xCD20 bispecific antibody, has demonstrated deep, durable responses with a manageable safety profile as a single agent in patients with R/R DLBCL. Based on these data, epcoritamab SC was approved by the US FDA for the treatment of adults with R/R DLBCL, not otherwise specified, including DLBCL arising from indolent lymphoma, and high-grade B-cell lymphoma, after ≥2 lines of systemic therapy. In the EPCORE ™ NHL-2 phase 1/2 trial (NCT04663347), epcoritamab + GemOx treatment showed encouraging preliminary efficacy with overall expected and manageable safety in patients with R/R DLBCL who failed or were ineligible for ASCT. Here, we present updated results with longer follow-up.

Background:Cold agglutinin disease (CAD) is a rare, chronic autoimmune hemolytic anemia characterized by complement-mediated hemolysis. The classical complement inhibitor sutimlimab, is the first approved pharmacotherapy for treating patients with CAD. The second-generation complement inhibitor SAR445088 (BIVV020) is a humanized monoclonal antibody that selectively inhibits the activated form of C1s (sutimlimab inhibits total C1s). Furthermore, SAR445088 contains mutations that increase FcRn binding, preventing its degradation and allowing it to be recycled back into the system, resulting in reduced drug clearance and a prolonged half-life, which may allow a longer dosing interval than that of sutimlimab.

IntroductionAtaxia telangiectasia (A-T) is a multisystem disorder caused by biallelic germline pathogenic variants (PV) in the ATM gene. An important feature of A-T is an increased predisposition to cancer with a reported incidence of 25%, primarily attributed to hematological malignancies. Patients with A-T and cancer are usually excluded from therapeutic clinical trials, limited information thus exists concerning their treatment outcomes and toxicity profiles and consequently, optimal management strategies are unclear and an unmet need. In this multinational study, we aimed to investigate the characteristics and outcomes of leukemia and lymphoma in a large cohort of children with A-T and to determine risk factors which impact treatment outcome in order to generate consensus and data-based prospective treatment recommendations.

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Background:Clinical outcome of patients (pts) with diffuse large B-cell lymphoma (DLBCL) has improved during the last two decades. However, a significant proportion of DLBCL pts is still at risk of lymphoma relapse (REL)/progression or death due to progression. DLBCL pts with adverse clinical features, i.e., those with high IPI or CNS IPI scores are at the highest risk of lymphoma REL, systemic (S) or central nervous system (CNS) REL. CNS prophylaxis is questionable based on retrospective analyses. Moreover, the risk of S-REL should be discussed in those pts as well. However, the comparison of the risks of CNS vs S-REL within the different CNS IPI risk groups has not been shown.

Introduction:In the POLARIX study (NCT03274492), polatuzumab vedotin in combination with rituximab plus cyclophosphamide, doxorubicin, and prednisone (Pola-R-CHP) demonstrated prolonged progression-free survival (PFS) versus rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) in patients with previously untreated diffuse large B-cell lymphoma (DLBCL; Tilly et al. N Eng J Med 2022); the PFS benefit was maintained with longer follow-up (Herrera et al. Blood 2022). We previously validated the prognostic value of ctDNA at baseline, on treatment, and at the end of treatment in POLARIX (Herrera et al. Blood 2022). Here, we assess and compare the mutation landscape and molecular subtyping of DLBCL by plasma ctDNA versus tissue DNA using the LymphGen classifier.

Background:Primary mediastinal B-cell lymphoma (PMBCL) is clinically and biologically distinct from other types of aggressive lymphoma, it is characterized by a bulky mediastinal mass and most commonly occurs in women between 30 and 40 years of age. Although consolidation radiotherapy (RT) has yielded extremely positive outcomes in PMBCL, it carries a higher risk of long-term complications. Consequently, there has been an ongoing debate regarding the necessity of RT in patients responding to frontline immunochemotherapy.

Background:Cold agglutinin disease (CAD) is a rare, chronic, autoimmune hemolytic anemia mediated by the classical complement pathway (CP).Sutimlimab is a first-in-class, humanized, monoclonal antibody that selectively inhibits C1s of the C1 complex, preventing CP activation and CP-mediated hemolysis. CARDINAL (NCT03347396) was an open-label, single-arm, Phase 3 study of sutimlimab in patients with CAD and recent history of transfusion; CADENZA (NCT03347422) was a randomized, double-blind, placebo-controlled, Phase 3 study of sutimlimab in patients with CAD and no recent history of transfusion. Both studies had a 26-week treatment period (Part A) followed by a long-term extension (Part B), reporting data up to 2 years after the last patient finished Part A of CARDINAL and up to 1 year after the last patient finished Part A of CADENZA. With long-term treatment in both studies, sutimlimab demonstrated sustained efficacy with improvements in hemolysis and anemia, sustained clinically meaningful improvements in quality of life, and it had a favorable safety profile.

Mantle cell lymphoma (MCL) is a chronically relapsing B cell lymphoproliferative malignancy characterized by translocation t(11;14)(q13;q32), cyclin D1 overexpression and significant chromosomal instability. One of the main hypotheses of MCL relapses is a clonal evolution driven by therapy selection of subpopulations carrying adverse genetic and epigenetic aberrations. Our previous whole exome sequencing analysis of 25 MCL tumors showed that the majority of the detected single-nucleotide variants and copy number variants (CNV) were already detectable at diagnosis. To further analyze the subclonal structure of MCL at diagnosis and clonal evolution at relapse, we implemented single cell RNA sequencing analysis of five patients with MCL at diagnosis and at the first clinical relapse after failure of standard immunochemotherapy. All analyzed patients achieved at least partial remission.

Introduction:In the POLARIX study, polatuzumab vedotin in combination with rituximab plus cyclophosphamide, doxorubicin, and prednisone (Pola-R-CHP) demonstrated prolonged progression-free survival (PFS) vs rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) in patients (pts) with previously untreated diffuse large B-cell lymphoma (DLBCL; NCT03274492; Tilly et al. N Engl J Med 2022); the PFS benefit was sustained with longer follow-up (Herrera et al. Blood 2022). Exploratory analyses demonstrated a trend towards greater PFS improvement in activated B cell-like (ABC) DLBCL with Pola-R-CHP vs R-CHOP (Tilly et al. N Engl J Med 2022). Although not yet available for daily practice, more granular molecular subtypes of DLBCL beyond cell of origin (COO) classification have demonstrated poor prognosis with R-CHOP, including EZH2mutations/ BCL2translocations (EZB), MYD88/ CD79B-mutated (MCD; as defined by LymphGen; Wright et al. Cancer Cell 2020), and dark zone gene expression signature (DZsig; Alduaij et al. Blood 2023). Here, in a post hoc exploratory analysis, we investigate the prevalence and clinical outcomes of molecularly defined subtypes of DLBCL in pts treated with Pola-R-CHP vs R-CHOP in POLARIX.

Large body of evidence suggests that hypoxia drives aggressive molecular features irrespective of cancer type. Non-Hodgkin lymphomas (NHL) are the most common hematologic malignancies characterized by widespread disease and frequent involvement of diverse hypoxic microenvironments (e.g., bone marrow, malignant effusions, large lymphoma masses). Impact of long-term hypoxia on the biology of lymphoma cells and its potential role in mediating drug resistance and disease relapses due to adaptive changes shaped by the hypoxic microenvironment remain only partially understood.

Agents targeting B-cell receptor (BCR) signaling-associated kinases such as Bruton tyrosine kinase (BTK) or phosphatidylinositol 3-kinase can induce mobilization of neoplastic B cells from the lymphoid tissues into the blood, which makes them potentially ideal to combine with anti-CD20 monoclonal antibodies (such as rituximab, obinutuzumab, or ofatumumab) for treatment of B-cell lymphomas and chronic lymphocytic leukemia (CLL). Here we show that interactions between leukemia cells and stromal cells (HS-5) upregulate CD20 on CLL cells and that administering ibrutinib downmodulates CD20 (MS4A1) expression in vivo. We observed that CLL cells that have recently exited the lymph node microenvironment and moved into the peripheral blood (CXCR4dimCD5bright subpopulation) have higher cell surface levels of CD20 than the cells circulating in the bloodstream for a longer time (CXCR4brightCD5dim cells). We found that CD20 is directly upregulated by CXCR4 ligand stromal cell-derived factor 1 (SDF-1α, CXCL12) produced by stromal cells, and BTK-inhibitor ibrutinib and CXCR4-inhibitor plerixafor block SDF-1α–mediated CD20 upregulation. Ibrutinib also downmodulated Mcl1 levels in CLL cells in vivo and in coculture with stromal cells. Overall, our study provides a first detailed mechanistic explanation of CD20 expression regulation in the context of chemokine signaling and microenvironmental interactions, which may have important implications for microenvironment-targeting therapies.

Background