Prognostic Significance of Cytokine Release Syndrome in B Cell Hematological Malignancies Patients After Chimeric Antigen Receptor T Cell Therapy.

Cytokine release syndrome (CRS) is the most common on-target toxicity of chimeric antigen receptor (CAR) T cell therapy. However, the prognostic significance of CRS has not been well elucidated. The aim of our study was to evaluate the association between CRS and efficacy after anti-CD19 CAR-T therapy in a retrospective cohort of 22 patients with relapsed/refractory B cell hematological malignancies. The complete remission (CR) rates after CAR-T therapy were 68%, and median value for progression-free survival (PFS) was 6.8 months. Eight of 22 (36.4%) patients showed ≥ grade 2 CRS. Statistical analysis found that patients with ≥ grade 2 CRS had higher CR rates and longer PFS than those with < grade 2 CRS. Moreover, bridging hematopoietic stem cell transplantation was another independent predictor for PFS. These data suggested that appropriate CRS may be beneficial to the efficacy of CAR-T therapy. The Clinical Trial Registration number is NCT03110640, NCT03302403.

Loss of synergistic transcriptional feedback loops drives diverse B-cell cancers.

BACKGROUND: The most common B-cell cancers, chronic lymphocytic leukemia/lymphoma (CLL), follicular and diffuse large B-cell (FL, DLBCL) lymphomas, have distinct clinical courses, yet overlapping "cell-of-origin". Dynamic changes to the epigenome are essential regulators of B-cell differentiation. Therefore, we reasoned that these distinct cancers may be driven by shared mechanisms of disruption in transcriptional circuitry. METHODS: We compared purified malignant B-cells from 52 patients with normal B-cell subsets (germinal center centrocytes and centroblasts, naïve and memory B-cells) from 36 donor tonsils using >325 high-resolution molecular profiling assays for histone modifications, open chromatin (ChIP-, FAIRE-seq), transcriptome (RNA-seq), transcription factor (TF) binding, and genome copy number (microarrays). FINDINGS: From the resulting data, we identified gains in active chromatin in enhancers/super-enhancers that likely promote unchecked B-cell receptor signaling, including one we validated near the immunoglobulin superfamily receptors FCMR and PIGR. More striking and pervasive was the profound loss of key B-cell identity TFs, tumor suppressors and their super-enhancers, including EBF1, OCT2(POU2F2), and RUNX3. Using a novel approach to identify transcriptional feedback, we showed that these core transcriptional circuitries are self-regulating. Their selective gain and loss form a complex, iterative, and interactive process that likely curbs B-cell maturation and spurs proliferation. INTERPRETATION: Our study is the first to map the transcriptional circuitry of the most common blood cancers. We demonstrate that a critical subset of B-cell TFs and their cognate enhancers form self-regulatory transcriptional feedback loops whose disruption is a shared mechanism underlying these diverse subtypes of B-cell lymphoma. FUNDING: National Institute of Health, Siteman Cancer Center, Barnes-Jewish Hospital Foundation, Doris Duke Foundation.

CAR-T cell therapy: practical guide to routine laboratory monitoring.

Chimeric antigen receptor (CAR)-T cell therapy is a genetically-modified cellular immunotherapy that has a current established role in the treatment of relapsed/refractory B-cell acute lymphoblastic leukaemia and diffuse large B-cell lymphoma, with emerging utility in a spectrum of other haematological and solid organ malignancies. It is associated with a number of characteristic toxicities, most notably cytokine release syndrome and neurotoxicity, for which laboratory testing can aid in the prediction of severity and in monitoring. Other toxicities, such as cytopenias/marrow hypoplasia, hypogammagloblinaemia and delayed immune reconstitution are recognised and require monitoring due to the implications for infection risk and prophylaxis. The detection or quantitation of circulating CAR-T can be clinically useful, and is achieved through both direct methods, if available, or indirect/surrogate methods. It is important that the laboratory is informed of the CAR-T therapy and target antigen whenever tissue is collected, both for response assessment and investigation of possible relapse, so that the expression of the relevant antigen can be assessed, in order to distinguish antigen-positive and -negative relapses. Finally, the measurement of circulating tumour DNA has an evolving role in the surveillance of malignancy, with evidence of its utility in the post-CAR-T setting, including predicting patients who will inevitably experience frank relapse, potentially allowing for pre-emptive therapy.

Occult Diffuse Neoplasm in the Lungs: Intravascular Large B-Cell Lymphoma.

BACKGROUND: Intrathoracic involvement with lymphomas is common and manifests lymphadenopathy as well as a wide spectrum of imaging abnormalities in the lungs. Intravascular large B-cell lymphoma (IVLBCL) is a rare extranodal subtype of large B-cell lymphoma that typically involves small blood vessels and is difficult to detect. METHODS: Using a computer-assisted search, we identified patients with histopathologically proven IVLBCL in the lungs at Mayo Clinic from 2001 through 2018. Medical records, imaging studies, and pathologic specimens were reviewed. RESULTS: A total of 5 patients were diagnosed with a median age at diagnosis of 68 years (range, 44-73); 4 patients were male. The diagnosis of IVLBCL was achieved by surgical lung biopsy in 3 and at autopsy in 2. At presentation, all 5 patients had dyspnea and systemic symptoms including fever, fatigue, night sweats, and/or weight loss. Chest radiography and computed tomography (CT) failed to demonstrate the diffuse infiltrative process; positron emission tomography (PET) scan performed in 2 patients did not show fluorodeoxyglucose (FDG) uptake in the lungs. Pulmonary function tests obtained in 3 patients showed reduced diffusing capacity in all; transthoracic echocardiography yielded evidence of pulmonary hypertension in 2 of 4 patients. All 3 patients diagnosed antemortem underwent chemotherapy with 1 patient remaining alive at 4 years after diagnosis. CONCLUSIONS: IVLBCL is difficult to diagnose given variable and nonspecific clinical presentations. Microvascular disease processes such as IVLBCL should be kept in mind in cases of undiagnosed progressive dyspnea accompanied by systemic symptoms even when imaging studies are unrevealing.

Analysis and Clinical Characteristics of 23 Cases of Bone Marrow Necrosis.

BACKGROUND: Bone marrow necrosis (BMN) is a rare secondary disorder of many discrepant neoplastic processes. The etiology is diverse, and malignancy is the most common background disease. PATIENTS AND METHODS: Between 2005 and 2019, a total of 23 cases of BMN were detected and analyzed at Zhujiang Hospital and Nanfang Hospital. RESULTS: In our study, the 40-60-year-old age group was the one with the highest incidence of BMN (n = 12, 52.2%). The background diseases of patients with BMN varied. Eighteen (78.3%) of 23 patients were diagnosed with hematologic diseases at the same time, most of which were acute B lymphocytic leukemia (n = 8, 34.8%). The complete blood count of these 23 patients noted a decrease in hemoglobin (100%), a decrease or increase in white blood cells and neutrophils, and thrombocytopenia (78.3%). The levels of lactate dehydrogenase (> 300 U/L) and serum ferritin (> 500 µg/L) were elevated in all patients, and 16 (94.1%) of 17 patients presented with increased d-dimer levels. The 2-week cumulative survival and 2-year cumulative survival of patients with BMN were 56.5% and 47.4%, respectively. The mortality probability within 2 weeks was 43.5%, and the adjusted mortality probability was 26.7% within 2 weeks to 2 years, indicating that patients with BMN had the greatest risk of death within 2 weeks. CONCLUSION: BMN patients with B lymphocytic leukemia as the background disease had a better prognosis than those with other background diseases. BMN of unknown etiology may have an extremely poor prognosis. Therefore, diagnosing the background disease plays an important role in the treatment of BMN.

Clinical and laboratory features associated with myeloperoxidase expression in pediatric B-lymphoblastic leukemia.

BACKGROUND: B-lymphoblastic leukemia (B-ALL) is the most common childhood malignancy, and its diagnosis requires immunophenotypically demonstrating blast B cell lineage differentiation. Expression of myeloperoxidase (MPO) in B-ALL is well-described and it has been recognized that a diagnosis of mixed phenotype acute leukemia should be made cautiously if MPO expression is the sole myeloid feature in these cases. We sought to determine whether MPO expression in pediatric B-ALL was associated with differences in laboratory, immunophenotypic, or clinical features. METHODS: We reviewed clinical, diagnostic bone marrow flow cytometry, and laboratory data for all new B-ALL diagnoses at our pediatric institution in 5 years. Cases were categorized as MPO positive (MPO+) or negative (MPO-) using a threshold of ≥20% blasts expressing MPO at intensity greater than the upper limit of normal lymphocytes on diagnostic bone marrow flow cytometry. RESULTS: A total of 148 cases were reviewed, 32 of which (22%) were MPO+. MPO+ B-ALL was more frequently hyperdiploid and less frequently harbored ETV6-RUNX1; no MPO+ cases had KMT2A rearrangements or BCR-ABL1. Although not significantly so, MPO+ B-ALL was less likely than MPO- B-ALL to have positive end-of-induction minimal residual disease studies (9.4 and 24%, respectively), but relapse rates and stem cell transplantation rates were similar between groups. Aberrant expression of other more typically myeloid markers was similar between these groups. CONCLUSION: In our study cohort, MPO+ B-ALL showed minimal residual disease persistence less often after induction chemotherapy but otherwise had similar clinical outcomes to MPO- B-ALL, with similar rates of additional myeloid antigen aberrancy.

Immunophenotypic shift in the B-cell precursors from regenerating bone marrow samples: A critical consideration for measurable residual disease assessment in B-lymphoblastic leukemia.

Accurate knowledge of expression patterns/levels of commonly used MRD markers in regenerative normal-B-cell-precursors (BCP) is highly desirable to distinguish leukemic-blasts from regenerative-BCP for multicolor flow cytometry (MFC)-based measurable residual disease (MRD) assessment in B-lymphoblastic leukemia (B-ALL). However, the data highlighting therapy-related immunophenotypic-shift in regenerative-BCPs is scarce and limited to small cohort. Herein, we report the in-depth evaluation of immunophenotypic shift in regenerative-BCPs from a large cohort of BALL-MRD samples. Ten-color MFC-MRD analysis was performed in pediatric-BALL at the end-of-induction (EOI), end-of-consolidation (EOC), and subsequent-follow-up (SFU) time-points. We studied normalized-mean fluorescent intensity (nMFI) and coefficient-of-variation of immunofluorescence (CVIF) of CD10, CD19, CD20, CD34, CD38, and CD45 expression in regenerative-BCP (early, BCP1 and late, BCP2) from 200 BALL-MRD samples, and compared them with BCP from 15 regenerating control (RC) TALL-MRD samples and 20 treatment-naïve bone-marrow control (TNSC) samples. Regenerative-BCP1 showed downregulation in CD10 and CD34 expression with increased CVIF and reduced nMFI (p < 0.001), upregulation of CD20 with increased nMFI (p = 0.014) and heterogeneous CD45 expression with increased CVIF (p < 0.001). Immunophenotypic shift was less pronounced in the BCP2 compared to BCP1 compartment with increased CVIF in all but CD45 (p < 0.05) and reduced nMFI only in CD45 expression (p = 0.005). Downregulation of CD10/CD34 and upregulation of CD20 was higher at EOI than EOC and SFU time-points (p < 0.001). Regenerative-BCPs are characterized by the significant immunophenotypic shift in commonly used B-ALL-MRD markers, especially CD10 and CD34 expression, as compared to treatment-naïve BCPs. Therefore, the templates/database for BMRD analysis must be developed using regenerative-BCP.

Constitutive Activation of RAS/MAPK Pathway Cooperates with Trisomy 21 and Is Therapeutically Exploitable in Down Syndrome B-cell Leukemia.

PURPOSE: Children with Down syndrome (constitutive trisomy 21) that develop acute lymphoblastic leukemia (DS-ALL) have a 3-fold increased likelihood of treatment-related mortality coupled with a higher cumulative incidence of relapse, compared with other children with B-cell acute lymphoblastic leukemia (B-ALL). This highlights the lack of suitable treatment for Down syndrome children with B-ALL. EXPERIMENTAL DESIGN: To facilitate the translation of new therapeutic agents into clinical trials, we built the first preclinical cohort of patient-derived xenograft (PDX) models of DS-ALL, comprehensively characterized at the genetic and transcriptomic levels, and have proven its suitability for preclinical studies by assessing the efficacy of drug combination between the MEK inhibitor trametinib and conventional chemotherapy agents. RESULTS: Whole-exome and RNA-sequencing experiments revealed a high incidence of somatic alterations leading to RAS/MAPK pathway activation in our cohort of DS-ALL, as well as in other pediatric B-ALL presenting somatic gain of the chromosome 21 (B-ALL+21). In murine and human B-cell precursors, activated KRASG12D functionally cooperates with trisomy 21 to deregulate transcriptional networks that promote increased proliferation and self renewal, as well as B-cell differentiation blockade. Moreover, we revealed that inhibition of RAS/MAPK pathway activation using the MEK1/2 inhibitor trametinib decreased leukemia burden in several PDX models of B-ALL+21, and enhanced survival of DS-ALL PDX in combination with conventional chemotherapy agents such as vincristine. CONCLUSIONS: Altogether, using novel and suitable PDX models, this study indicates that RAS/MAPK pathway inhibition represents a promising strategy to improve the outcome of Down syndrome children with B-cell precursor leukemia.

CD19 chimeric antigen receptor-T cells in B-cell leukemia and lymphoma: current status and perspectives.

The approval of tisagenlecleucel and axicabtagene ciloleucel represents a breakthrough in the field of immune and cellular therapy for hematologic malignancies. These anti-CD19 chimeric antigen receptor-T cells (CAR) proved to be highly effective in the treatment of relapsed/refractory B-cell acute lymphoblastic leukemia (B-ALL) and specific histologic subtypes of B-cell non-Hodgkin lymphomas. This expert review aims to summarize the current available research evidence in this field, with a special focus on the different challenges faced by treating physicians, and we also provide future perspectives.

[Biological diagnosis of mature B cell malignancies]. / Apport des examens de biologie dans la prise en charge des hémopathies lymphoïdes B matures. L'intérêt de l'intégration des données clinicobiologiques.

Diagnosis of mature B cell malignancies is highly multidisciplinary. Biological tools provide diagnostic, prognostic and theranostic information. Biological hematology allows considering mature B cell diseases from two perspectives : cellular and molecular approaches. Cytomorphology and flow cytometry are tools from cell hematology. Conventional cytogenetics, FISH and molecular biology are tools from molecular hematology. NGS is a new technique that could dramatically change diagnostic and therapeutic management of B cell malignancies in the near future. Integration of clinical, pathological and biological data allows for personalized management of these diseases.

Updates on CAR T-cell therapy in B-cell malignancies.

By increasing disease-free survival and offering the potential for long-term cure, chimeric antigen receptor (CAR) T-cell therapy has dramatically expanded therapeutic options among those with high-risk B-cell malignancies. As CAR T-cell utilization evolves however, novel challenges are generated. These include determining how to optimally integrate CAR T cells into standard of care and overcoming mechanisms of resistance to CAR T-cell therapy, such as evolutionary stress induced on cancer cells leading to immunophenotypic changes that allow leukemia to evade this targeted therapy. Compounding these challenges are the limited ability to determine differences between various CAR T-cell constructs, understanding the generalizability of trial outcomes from multiple sites utilizing unique CAR manufacturing strategies, and comparing distinct criteria for toxicity grading while defining optimal management. Additionally, as understanding of CAR behavior in humans has developed, strategies have appropriately evolved to proactively mitigate toxicities. These challenges offer complimentary insights and guide next steps to enhance the efficacy of this novel therapeutic modality. With a focus on B-cell malignancies as the paradigm for effective CAR T-cell therapy, this review describes advances in the field as well as current challenges and future directions.

The Utilization of Chromosomal Microarray Technologies for Hematologic Neoplasms: An ACLPS Critical Review.

OBJECTIVES: Chromosome (G-banding) and fluorescence in situ hybridization (FISH) serve as the primary methodologies utilized for detecting genetic aberrations in hematologic neoplasms. Chromosomal microarray can detect copy number aberrations (CNAs) with greater resolution when compared to G-banding and FISH, and can also identify copy-neutral loss of heterozygosity (CN-LOH). The purpose of our review is to highlight a preselected group of hematologic neoplasms for which chromosomal microarray has the greatest clinical utility. METHODS: A case-based approach and review of the literature was performed to identify the advantages and disadvantages of utilizing chromosomal microarray for specific hematologic neoplasms. RESULTS: Chromosomal microarray identified CNAs and CN-LOH of clinical significance, and could be performed on fresh or paraffin-embedded tissue and liquid neoplasms. Microarray studies could not detect balanced rearrangements, low-level clones, or distinguish independent clones. CONCLUSIONS: When utilized appropriately, chromosomal microarray can provide clinically significant information that complements traditional cytogenetic testing methodologies.

Investigational Antibody-Drug Conjugates for Treatment of B-lineage Malignancies.

Antibody-drug conjugates (ADCs) are tripartite molecules consisting of a monoclonal antibody, a covalent linker, and a cytotoxic payload. ADC development has aimed to target the specificity inherent in antigen-antibody interactions to deliver potent cytotoxins preferentially to tumor cells and maximize antitumor activity and simultaneously minimize off-target toxicity. The earliest ADCs provided disappointing results in the clinic; however, the lessons learned regarding the need for human or humanized antibodies, more stable linkers, and greater potency payloads led to improved ADCs. Three ADCs, gemtuzumab ozogamicin, brentuximab vedotin (BV), and inotuzumab ozogamicin, have been approved for hematologic malignancies. Site-specific conjugation methods have now resulted in a new generation of more uniform, molecularly defined ADCs. These are expected to display improved in vivo properties and have recently entered the clinic. We reviewed investigational ADCs currently in clinical testing for the treatment of B-cell lineage malignancies, including leukemias, lymphomas, and multiple myeloma. The rationales for antigen targeting, data reported to date, current trial status, and preclinical results for several newer ADCs expected to enter first-in-human studies are presented. Owing to the large number of ongoing and reported BV clinical studies, only the studies of BV for diffuse large B-cell lymphoma and those combining BV with checkpoint inhibitors in B-lineage malignancies have been reviewed. With > 40 ongoing clinical trials and 7 investigational ADCs already having advanced to phase II studies, the role of ADCs in the armamentarium for the treatment of B-lineage malignancies continues to be elucidated.

Quantitative assessment of informative immunophenotypic markers increases the diagnostic value of immunophenotyping in mature CD5-positive B-cell neoplasms.

BACKGROUND: The data on the clinical utility of the quantitative assessment of immunophenotypes in distinguishing mature CD5-positive B-cell neoplasms is limited. The study aim was to assess the diagnostic value of the quantitative assessment of a panel of 18 markers and to identify the most informative ones. METHODS: The immunophenotype of the neoplastic population was determined in diagnostic specimens from 188 patients. BD FACSCanto II flow cytometer and FACSDiva software were used to analyze the positivity/negativity and mean fluorescence intensity (MFI) of the surface expression of 18 markers. Advanced data mining methods were used to define the key differential diagnostic features of CLL/SLL (chronic lymphocytic leukemia/small lymphocytic lymphoma), MCL (mantle cell lymphoma), and CD5+ MZL (marginal zone lymphoma). RESULTS: The most informative markers for the distinction of CLL/SLL, MCL, CD5+ MZL, including atypical cases, were the MFI values of CD79b, CD20, CD23, CD43, CD38, CD11c, FMC7, CD200, kappa light chain, and their combinations. CD23 and CD200 were the most discriminant between CLL/SLL and MCL and CD23 plus CD79b between CLL/SLL and CD5+ MZL. The quantitative analysis of the most informative markers failed to accurately distinguish MCL and CD5+ MZL. The study highlights the data mining methods for the analysis and selection of the most informative immunophenotypic markers and for the design of a predictive model (diagnostic classifier), minimizing the subjectivity of expert-based assessment. CONCLUSIONS: Our data confirmed that the quantification of the expression of informative markers increases the diagnostic value of immunophenotyping in mature CD5+ B-cell neoplasms. © 2017 International Clinical Cytometry Society.

Hairy Cell Leukemia, Version 2.2018, NCCN Clinical Practice Guidelines in Oncology.

Hairy cell leukemia (HCL) is a rare type of indolent B-cell leukemia, characterized by symptoms of fatigue and weakness, organomegaly, pancytopenia, and recurrent opportunistic infections. Classic HCL should be considered a distinct clinical entity separate from HCLvariant (HCLv), which is associated with a more aggressive disease course and may not respond to standard HCL therapies. Somatic hypermutation in the IGHV gene is present in most patients with HCL. The BRAF V600E mutation has been reported in most patients with classic HCL but not in those with other B-cell leukemias or lymphomas. Therefore, it is necessary to distinguish HCLv from classic HCL. This manuscript discusses the recommendations outlined in the NCCN Guidelines for the diagnosis and management of classic HCL.

The use of ofatumumab in the treatment of B-cell malignancies.

Ofatumumab has been extensively studied in the treatment of B-cell malignancies. Currently, it has been approved for the treatment of chronic lymphocytic leukemia in a number of different situations. However, there is still no compelling evidence confirming the superiority of ofatumumab over rituximab in vivo. In this article, we summarize the currently available clinical data supporting the use of ofatumumab in the treatment of B-cell malignancies. The clinical studies were searched from clinicaltrials.gov with the key words ofatumumab, HuMax-CD20. Out of 115 trials available, studies for B-cell malignancies were selected, followed by selection of completed studies with results and active ongoing studies. The results from completed studies were thoroughly analyzed and active ongoing studies were listed in tables.