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Despite their unprecedented success in relapsed/refractory (R/R) large B-cell lymphoma (LBCL), anti-CD19 CAR T cells are associated with significant toxicity, and more than half of patients relapse. As monocytes emerged as key players in CAR therapy, we sought to evaluate the evolution of HLA-DR expression on monocytes (mHLA-DR) before and after commercial anti-CD19 CAR T-cell infusion in a large cohort (n = 103) of patients with R/R LBCL and its association with adverse events and treatment response. Cy-Flu-based lymphodepletion (LD) upregulated mHLA-DR in 79% of the cases, whereas in 2l% of cases (15 patients), the mHLA-DR level decreased after LD, and this decrease was associated with poorer outcome. Low mHLA-DR at day minus 7 (D−7) (

VEXAS syndrome has an unmet need for therapeutic interventions. Even if few data exist regarding the treatment of this newly described syndrome, different options can be proposed given the unique pathophysiological consequences of the clonal dominance of UBA1 mutated hematopoietic stem cells. To date, allogeneic transplantation is the only curative option, but many questions remain regarding the selection of eligible patients, the conditioning regimen or management of toxicities that may be unique to VEXAS patients. Alternatively, drugs used in myelodysplastic syndrome such as hypomethylating agents or lenalidomide are interesting candidates, which could theoretically have also an effect on the clone. Another strategy is to target the inflammatory cascade, by inhibiting proinflammatory cytokines (such as TNFα, IL1, IL6) or effector cells, for example with JAK inhibitors. Whatever the choice of treatment for VEXAS patients, supportive care is always needed to be considered to manage frequent complications such as cytopenia, thrombosis and infections. Finally, we discuss the challenges of the design of clinical trials for VEXAS patients, from inclusion criteria to clinical and biological endpoints of activity.

Chimeric antigen receptors (CAR)-T cells are genetically engineered T-lymphocytes redirected with a predefined specificity to any target antigen, in a non-HLA restricted manner, therefore combining antibody-type specificity with effector T-cell function. This strategy was developed some thirty years ago, after extensive work established the key role of the immune system against cancer. The first-engineered T-cell with chimeric molecule was designed in 1993 by Israeli immunologist Zelig Eshhar. Since then, several modifications took place, including the addition of co-stimulatory domain, to further improve CAR-T cell anti-tumor potency. The first clinical application of CAR-T cell was done in Rotterdam in 2005 for metastatic renal cell carcinoma and simultaneously at the National Cancer Institute (NCI) for metastatic ovarian cancer. These pioneered studies failed to demonstrate a therapeutic benefit, but warning emerged concerning their safety of use. The real clinical success came with anti-CD19 CAR-T cells, used since 2009 by Steven Rosenberg at the NCI in a patient with refractory follicular lymphoma and in 2011 by Carl June and David Porter from the University of Pennsylvania in patients with chronic lymphocytic leukemia and B-cell acute lymphoblastic leukemia. From that time, large centers in North America have embarked in several early phase and pivotal trials that have demonstrated unprecedent response rate in heavily pretreated chemo refractory patient with B-cell malignancies. Theses clinical success have led to the approval of three anti-CD19 CAR-T cells products for the management of B-cell malignancies in the United States and in Europe as of December 2020.

In this retrospective study, we report 70 cases of Epstein-Barr virus (EBV)+ diffuse large B-cell lymphoma not otherwise specified (DLBCL-NOS) among 1696 DLBCL-NOS cases diagnosed between 2006 and 2019 (prevalence of 4.1%). At diagnosis, median age was 68.5 years; 79% of the cases presented with an advanced-stage disease (III-IV), 48% with extranodal lesions, and 14% with an hemophagocytic lymphohistiocytosis (HLH) (8 at diagnosis and 1 on therapy). A total of 46 cases presented a polymorphic pattern, and 21 were monomorphic. All had a non-germinal center B phenotype, with the majority of tumor cells expressing CD30 and programmed death ligand 1 (98% and 95%, respectively). Type II and III EBV latency was seen in 88% and 12% of the cases, respectively. Patients were treated with immunochemotherapy (59%) or chemotherapy (22%), and 19% received palliative care due to advanced age and altered performance status. After a median follow-up of 48 months, progression-free survival (PFS) and overall survival (OS) at 5 years were 52.7% and 54.8%, respectively. Older age (>50 years) and HLH were associated with shorter PFS and OS in multivariate analysis (PFS: hazard ratio [HR], 14.01; 95% confidence interval [CI], 2.34-83.97; and HR, 5.78; 95% CI, 2.35-14.23; OS: HR, 12.41; 95% CI, 1.65-93.53; and HR, 6.09; 95% CI, 2.42-15.30, respectively). Finally, using a control cohort of 425 EBV− DLBCL-NOS, EBV positivity was associated with a shorter OS outcome within patients >50 years (5-year OS, 53% [95% CI, 38.2-74] vs 60.8% [95% CI, 55.4-69.3], P = .038), but not in younger patients.

As the impact of targeted next-generation sequencing (TNGS) on daily diagnosis has not been evaluated, we performed TNGS (46 genes) on lymphomas of unclear subtype following expert haematopathological review. The potential impact on patient care and modifications of final diagnosis were divided into major and minor changes according to the European Society of Medical Oncology (ESMO) guidelines. Among 229 patients [19 primary central nervous system lymphomas (PCNSL), 48 large B-cell lymphomas (LBCLs), 89 small BCLs (SBCLs), seven Hodgkin lymphomas (HL), 66 T-cell lymphomas], the overall concordance rate of histological and TNGS diagnosis was 89·5%. TNGS confirmed the histological diagnosis in 144 cases (62·9%), changed the diagnosis in 24 cases (10·5%) and did not help to clarify diagnosis in 61 cases (26·7%). Modifications to the final diagnosis had a clinical impact on patient care in 8·3% of cases. Diagnostic modifications occurred in all types of lymphoma except in PCNSL and HL; the modification rate was 14·6% in SBCL and 12·5% in LBCL. While comparing informative and uninformative cases, no differences were found in terms of DNA amplification, quality or depth of sequencing and biopsy type. The present study highlights that TNGS may directly contribute to a more accurate diagnosis in difficult-to-diagnose lymphomas, thus improving the clinical management in routine practice.

Adult T-cell leukemia (ATL) is a lymphoid neoplasm caused by human T-cell leukemia virus type 1 (HTLV-1), which encodes the transcriptional activator Tax, which participates in the immortalization of infected T cells. ATL is classified into 4 subtypes: smoldering, chronic, acute, and lymphoma. We determined whether natural killer receptors (NKRs) were expressed in ATL. NKR expression (KIR2DL1/2DS1, KIR2DL2/2DL3/2DS2, KIR3DL2, NKG2A, NKG2C, and NKp46) was assessed in a discovery cohort of 21 ATL, and KIR3DL2 was then assessed in 71 patients with ATL. KIR3DL2 was the only NKR among those studied frequently expressed by acute-type vs lymphoma- and chronic/smoldering-type ATL (36 of 40, 4 of 16, and 1 of 15, respectively; P = .001), although acute- and lymphoma-type ATL had similar mutation profiles by targeted exome sequencing. The correlation of KIR3DL2 expression with promoter demethylation was determined by microarray-based DNA methylation profiling. To explore the role of HTLV-1, KIR3DL2 and TAX messenger RNA (mRNA) expression levels were assessed by PrimeFlow RNA in primary ATL and in CD4+ T cells infected with HTLV-1 in vitro. TAX mRNA and KIR3DL2 protein expressions were correlated on ATL cells. HTLV-1 infection triggered KIR3DL2 by CD4+ cells but Tax alone did not induce KIR3DL2 expression. Ex vivo, autologous, antibody-dependent cell cytotoxicity using lacutamab, a first-in-class anti-KIR3DL2 humanized antibody, selectively killed KIR3DL2+ primary ATL cells ex vivo. To conclude, KIR3DL2 expression is associated with acute-type ATL. Transcription of KIR3DL2 may be triggered by HTLV-1 infection and correlates with hypomethylation of the promoter. The benefit of targeting KIR3DL2 with lacutamab is being further explored in a randomized phase 2 study in peripheral T-cell lymphoma, including ATL (registered on https://clinicaltrials.gov as #NCT04984837).

New agents for managing B-cell non-Hodgkin lymphomas (NHLs) are needed, particularly for high-risk and relapsed or refractory patients. Antibody-drug conjugates (ADCs) provide targeted drug delivery to tumors with a broaden therapeutic index of cytotoxic agent, reducing their systemic toxicity while increasing intracellular concentrations. Polatuzumab vedotin, an anti-CD79b conjugated to the microtubule inhibitor monomethyl auristatin E (MMAE) raises particular interest.We discuss here polatuzumab vedotin development, challenges of designing a successful ADC, preclinical studies and recent trials, leading to FDA approval and the ongoing phase III POLARIX trial.Clinical data from early studies hold promises for polatuzumab vedotin in association with rituximab-bendamustine in relapsed or refractory (R/R) DLBCL and other combinations are investigated in this setting. In first line, with rituximab, cyclophosphamide, doxorubicin and prednisone (R-CHP), promising results lead to develop the phase III POLARIX trial that may represent a new advance for untreated patients. If dosing and scheduling are adequately managed to avoid peripheral neuropathy risk, polatuzumab vedotin might become a key component of DLBCL therapeutic management. This antibody drug conjugate also offers new opportunities of combination with non-cytotoxic agents or immunological interventions that might reshape the treatment of DLBCL in the future.

The analysis of circulating tumor DNA (ctDNA) released by tumor cells holds great promise for patients with lymphoma, to refine the diagnostic procedure, clarify the prognosis, monitor the response to treatment, and detect relapses earlier. One of the main challenges of the coming years is to adapt techniques from highly specialized translational teams to routine laboratories as this requires a careful technical and clinical validation, and we have to achieve this as fast as possible to transform a promising biomarker into a routine analysis to have a direct consequence on patient care. Whatever the analytical technology used, the prerequisite is to obtain high yields of ctDNA of optimal quality. In this review, we propose a step-by-step description of the preanalytical process to obtain high-quality ctDNA, emphasizing the technical choices that need to be made and the experimental data that can support these choices.

In the rituximab era, one-third of diffuse large B-cell lymphoma patients experience relapse/refractory disease after first-line anthracycline-based immunochemotherapy. Optimal management remains an unmet medical need. The aim of this study was to report the outcomes of a cohort of refractory patients according to their patterns of refractoriness and the type of salvage option. We performed a retrospective analysis, which included 104 diffuse large B-cell lymphoma patients treated at Lyon Sud University Hospital (2002-2017) who presented with refractory disease. Refractoriness was defined as progressive/stable disease during first-line treatment (primary refractory, N = 47), a partial response after the end of first-line treatment that required subsequent treatment (residual disease, N = 19), or relapse within 1 year of diagnosis after an initial complete response (CR) (early relapse, N = 38). The 2-year overall survival (OS) rates for primary refractory, early relapse, and residual disease patients were 27%, 25%, and 52%, respectively, while the event-free survival rates for those groups were 13%, 13%, and 42%, respectively. In a univariate analysis, lactate dehydrogenase level, Ann Arbor stage, poor performance status, high age-adjusted International Prognostic Index score, and age > 65 years were associated with shorter OS. The use of rituximab and platinum-based chemo during the first salvage treatment was associated with prolonged OS. In a multivariate analysis, age (HR:2.06) and rituximab use (HR:0.54) were associated with OS. Among patients

The aim of this retrospective cohort study was to investigate the incidence of delayed methotrexate elimination in patients treated with high-dose methotrexate (≥1 g/m2 ) for haematological malignancy and to identify the impact of interacting drugs, especially proton-pump inhibitors (PPIs) and ranitidine. All patients treated with high-dose methotrexate over a 6 year period in the haematology department of the Lyon Sud University Hospital (Hospices Civils de Lyon, France) were included. Potential risk factors for delayed methotrexate elimination were tested in a generalized linear model by univariate analysis: patient age, gender, methotrexate dose, administration of PPI or ranitidine, and concomitant nephrotoxic drugs. A total of 412 cycles of methotrexate were administered to 179 patients. Proton-pump inhibitors were co-administered with methotrexate in 127 cycles and ranitidine in 192 cycles. Ninety-three cycles included no antacid drugs. A total of 918 plasma methotrexate assays were performed. Methotrexate concentrations were checked at 24 hours in 92% of cycles. Delayed methotrexate elimination was observed in 20.9% of cycles. A total of 63 cycles with delayed methotrexate elimination were only identified on plasma methotrexate measures at 72 hours: ie, plasma methotrexate was in the normal range at 24 and 48 hour post injection. Use of PPI/ranitidine or no antacid drugs did not increase risk of delayed elimination, with respectively delayed methotrexate elimination in 20.5%, 21.9%, and 19.4% of cycles (P = .89). Impaired baseline creatinine clearance showed significant association in univariate analysis. Fifteen patients showed grade 1 acute kidney injury, 1 grade 2, 2 grade 3, and none grade 4. For half of these cases, delayed methotrexate elimination was observed and the 2 grade 3 events appeared in patients treated with PPIs. This retrospective study suggests that there is no association between concomitant use of proton-pump inhibitors (pantoprazole and esomeprazole) or ranitidine and delayed methotrexate elimination.

Abstract 3483 Activated Hedgehog (HH) signaling was identified in our laboratory to contribute to cell survival, proliferation and chemotolerance of diffuse large B-cell lymphoma (DLBCL) (Leukemia 2010;24:1025 & Oncogene 2011, in press). The HH receptor complex is integrated by two main proteins, smoothened (SMO) and patched-1 (PTCH1). SMO is a seven-transmembrane G protein-coupled receptor that transduces HH signal to the cytoplasm and has glioma-associated oncogene homologue (GLI) proteins as major signaling transcription effectors. PTCH1 is a 12 transmembrane protein that inhibits SMO in the absence of HH ligands. Here, we investigated potential cross talk between SMO with the activation status of PI3K/AKT and NF-kB, two relevant oncogenic pathways in DLBCL. Using a small interfering (si)RNA approach and DLBCL cell lines of germinal center (GC) and activated B-cell (ABC) type we found that the expression levels of SMO modulate the activation status of AKT and canonical NF-KB pathways in DLBCL cells of GC type and mainly AKT in those of ABC type. In DLBCL cells of GC cell type, silencing SMO resulted in decrease of the phosphorylation levels of ser473p-AKT and ser536p-P65 and silencing PTCH1 resulted in increase of the phosphorylation levels of both proteins. The same silencing experimental approach in DLBCL cells of ABC type resulted in similar modulation in the activation status of the AKT but not, or to less extent, in the activation of NF-kB pathway. The modulation of the activation status of the NF-KB pathway was also confirmed using protein nuclear extracts and DNA binding ELISA assays. In cells of both DLBCL subtypes, silencing of the SMO transcriptional effector GLI1 showed no changes in the activation status of both pathways. The modulation in the activation status of AKT and NF-KB was also detected using SMO inhibitors, cyclopamine-KAAD and HhAntag (Genentech Inc) or activators, purmorphamine and recombinant HH protein. Combinatorial treatments with increasing concentrations of SMO inhibitors (cyclopamine and HhAntag [1.6, 3.2 and 4.8 μM]) with minimal lethal doses of Ly294002 (PI3K inhibitor) or BAY-11 (NF-KB inhibitor) were also performed. Using cell viability, and apoptosis (Annexin-V) assays, we found that combined treatments of PI3K or NF-KB inhibitors with a SMO inhibitor resulted in an additive/synergistic decrease of cell viability and increase of apoptosis in comparison to the treatments with SMO inhibitors alone. Taken together, our data shed novel light on the contribution of SMO on the activation of PI3K/AKT and NF-kB pathways in DLBCL. Our data also provide a rationale to use SMO inhibitors in combination with inhibitors of other oncogenic pathways such as PI3K/AKT and/or NF-KB for the treatment of patients with DLBCL. Disclosures: No relevant conflicts of interest to declare.