Outcome and feasibility of radiotherapy bridging in large B-cell lymphoma patients receiving CD19 CAR T in the UK.

Radiotherapy (RT) has potential synergistic effects with chimeric antigen receptor (CAR) T but is not widely used as bridging therapy due to logistical challenges and lack of standardised protocols. We analysed RT bridging in a multicentre national cohort of large B-cell lymphoma patients approved for 3L axicabtagene ciloleucel or tisagenlecleucel across 12 UK centres. Of 763 approved patients, 722 were leukapheresed, 717 had data available on bridging therapy. 169/717 (24%) received RT bridging, 129 as single modality and 40 as combined modality treatment (CMT). Of 169 patients, 65.7% had advanced stage, 36.9% bulky disease, 86.5% elevated LDH, 41.7% international prognostic index (IPI) ≥3 and 15.2% double/triple hit at the time of approval. Use of RT bridging varied from 11% to 32% between centres and increased over time. Vein-to-vein time and infusion rate did not differ between bridging modalities. RT-bridged patients had favourable outcomes with 1-year progression-free survival (PFS) of 56% for single modality and 47% for CMT (1-year PFS 43% for systemic bridging). This is the largest cohort of LBCL patients receiving RT bridging prior to CAR T reported to date. Our results show that RT bridging can be safely and effectively used even in advanced stage and high-risk disease, with low dropout rates and excellent outcomes.

The landscape of cytogenetic and molecular genetic methods in diagnostics for hematologic neoplasia.

Improvements made during the last decades in the management of patients with hematologic neoplasia have resulted in increase of overall survival. These advancements have become possible through progress in our understanding of genetic basis of different hematologic malignancies and their role in the current risk-adapted treatment protocols. In this review, we provide an overview of current cytogenetic and molecular genetic methods, commonly used in the genetic characterization of hematologic malignancies, describe the current developments in the cytogenetic and molecular diagnostics, and give an outlook into their future development. Furthermore, we give a brief overview of the most important public databases and guidelines for sequence variant interpretation.

Circulating tumor DNA for monitoring classic Hodgkin lymphoma patients: Correlation with FDG-PET/CT.

The value of circulating tumor DNA (ctDNA) as a biomarker of disease activity in classic Hodgkin lymphoma (cHL) patients has not yet been well established. By profiling primary tumors and ctDNA, we identified common variants between primary tumors and longitudinal plasma samples in most of the cases, confirming high spatial and temporal heterogeneity. Although ctDNA analyses mirrored HRS cell genetics overall, the prevalence of variants shows that none of them can be used as a single biomarker. Conversely, the estimation of hGE/mL, based on measures of total ctDNA, reflects disease activity and is almost perfectly correlated with standard parameters such as PET/CT that are associated with refractoriness.

Mosunetuzumab Safety Profile in Patients With Relapsed/Refractory B-cell Non-Hodgkin Lymphoma: Clinical Management Experience From a Pivotal Phase I/II Trial.

BACKGROUND: Mosunetuzumab is a CD20xCD3 T-cell engaging bispecific antibody approved in Europe and the United States for relapsed/refractory (R/R) follicular lymphoma (FL) after ≥ 2 prior therapies. MATERIALS AND METHODS: We present interim safety data from the mosunetuzumab GO29781 (NCT02500407) phase I/II dose-escalation study in R/R non-Hodgkin lymphoma (NHL), focusing on FL. RESULTS: Overall, 218 patients with R/R NHL, including 90 with R/R FL, received a median of eight 21-day cycles of intravenous mosunetuzumab with step-up dosing in Cycle (C) 1 (C1 Day [D] 1, 1 mg; C1D8, 2 mg; C1D15/C2D1, 60 mg; C3D1 and onwards, 30 mg). Cytokine release syndrome (CRS) was the most common adverse event (AE), occurring in 39.4% (NHL) and 44.4% (FL) of patients. Events occurred predominantly during C1 at the first loading dose; the majority were grade 1/2. CRS events were managed at the investigator's discretion with supportive care, steroids, and tocilizumab, based on protocol management guidelines. Immune effector cell-associated neurotoxicity syndrome was uncommon, reported in 0.9% (NHL) and 1.1% (FL) of patients. Neutropenia occurred in 27.5% (NHL) and 28.9% (FL) of patients (mostly grade 3/4) and could be effectively managed using granulocyte colony-stimulating factor. Tumor lysis syndrome occurred in 0.9% (NHL) and 1.1% (FL) of patients (all grade 3/4 with CRS; all resolved). CONCLUSION: Mosunetuzumab monotherapy as treatment for R/R B-cell NHL, including FL, was associated with low rates of severe AEs (including CRS) and is suitable for outpatient administration in the community setting. Adapted protocol guidance for the management of select AEs during mosunetuzumab treatment is included.

Death from mantle cell lymphoma limits sequential therapy, particularly after first relapse: Patterns of care and outcomes in a series from Australia and the United Kingdom.

Mantle cell lymphoma (MCL) is a B-cell non-Hodgkin lymphoma characterised by a heterogeneous clinical course. Patients can often receive sequential treatments, yet these typically yield diminishing periods of disease control, raising questions about optimal therapy sequencing. Novel agents, such as chimeric antigen receptor T-cell therapies and bispecific antibodies, show promise in relapsed MCL, but are often reserved for later treatment lines, which may underserve patients with aggressive disease phenotypes who die early in the treatment journey. To assess the problem of patient attrition from lymphoma-related death limiting sequential treatment, we performed a multicentre retrospective cohort analysis of 389 patients treated at Australian and UK centres over a 10-year period. Deaths from MCL increased after each treatment line, with 7%, 23% and 26% of patients dying from uncontrolled MCL after first, second and third lines respectively. Patients with older age at diagnosis and early relapse after induction therapy were at particular risk of death after second-line treatment. This limitation of sequential treatment by lymphoma-related death provides support for the trial of novel therapies in earlier treatment lines, particularly in high-risk patient populations.

HTLV-1 cell-free DNA in plasma as a potential biomarker in HTLV-1 carriers and adult T-cell leukemia-lymphoma.

Viral cell-free DNA (cfDNA) in plasma has been widely evaluated for detecting cancer and monitoring disease in virus-associated tumors. We investigated whether the amount of cfDNA of human T-cell leukemia virus type 1 (HTLV-1) correlates with disease state in adult T-cell leukemia-lymphoma (ATL). HTLV-1 cfDNA in aggressive ATL was significantly higher than that in indolent ATL and asymptomatic carriers. Notably, patients with lymphoma type represented higher HTLV-1 cfDNA amount than chronic and smoldering subtypes, though they had no abnormal lymphocytes in the peripheral blood. HTLV-1 cfDNA can be a universal biomarker that reflects the expansion of ATL clones.

SOHO State of the Art Updates and Next Questions | From Biology to Therapy: Progress in Hodgkin Lymphoma.

Classic Hodgkin lymphoma (HL) is a unique lymphoid malignancy where the malignant cells comprise only 1% to 2% of the total tumor cellularity. Over the past 2 decades, the treatment of HL has evolved drastically based on the advent of novel targeted therapies. Novel agents including programmed death-1 (PD-1) inhibitors, antibody-drug conjugates such as brentuximab vedotin, bispecific antibodies, and chimeric antigen receptor (CAR) T cell therapies have served to shape the management of HL in the frontline as well as the relapsed and refractory (R/R) setting. Some of these agents have been incorporated into treatment algorithms, while others are currently under investigation demonstrating promising results. This review focuses on highlighting the underlying tumor biology forming the basis of therapeutics in HL, and reviews some of the emerging and established novel therapies.

Humoral and cellular immune responses after three or four doses of BNT162b2 in patients with hematological malignancies.

OBJECTIVES: Initial responses to coronavirus disease 2019 vaccination are impaired in patients with hematological malignancies. We investigated immune responses after three or four doses of BNT162b2 in patients with myeloid and lymphoid malignancies compared to controls, and identified risk factors for humoral and cellular nonresponse 1 year after first vaccination. METHODS: In 407 hematological patients (45 myeloid, 362 lymphoid) and 98 matched controls, we measured immunoglobulin G (IgG) and neutralizing antibodies specific for the receptor-binding domain of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) at baseline, 3 weeks, 2, 6, and 12 months, and interferon-γ release at 12 months. RESULTS: In patients with lymphoid malignancies, SARS-CoV-2 receptor-binding domain IgG concentration and mean neutralizing capacity was lower than in controls at all time points. A diagnosis of chronic lymphocytic B-cell leukemia (CLL) or lymphoma was associated with humoral nonresponse at 12 months compared to having multiple myeloma/amyloidosis (p < .001 and p = .013). Compared to controls, patients with lymphoid malignancies had increased risk of cellular nonresponse. A lymphoma diagnosis was associated with lower risk of cellular nonresponse compared to patients with multiple myeloma/amyloidosis, while patients with CLL had comparable response rates to patients with multiple myeloma/amyloidosis (p = .037 and p = .280). CONCLUSIONS: In conclusion, long-term humoral and cellular immune responses to BNT162b2 were impaired in patients with lymphoid malignancies.

Liquid biopsies and minimal residual disease in lymphoid malignancies.

Minimal residual disease (MRD) assessment using peripheral blood instead of bone marrow aspirate/biopsy specimen or the biopsy of the cancerous infiltrated by lymphoid malignancies is an emerging technique with enormous interest of research and technological innovation at the current time. In some lymphoid malignancies (particularly ALL), Studies have shown that MRD monitoring of the peripheral blood may be an adequate alternative to frequent BM aspirations. However, additional studies investigating the biology of liquid biopsies in ALL and its potential as an MRD marker in larger patient cohorts in treatment protocols are warranted. Despite the promising data, there are still limitations in liquid biopsies in lymphoid malignancies, such as standardization of the sample collection and processing, determination of timing and duration for liquid biopsy analysis, and definition of the biological characteristics and specificity of the techniques evaluated such as flow cytometry, molecular techniques, and next generation sequencies. The use of liquid biopsy for detection of minimal residual disease in T-cell lymphoma is still experimental but it has made significant progress in multiple myeloma for example. Recent attempt to use artificial intelligence may help simplify the algorithm for testing and may help avoid inter-observer variation and operator dependency in these highly technically demanding testing process.

Cytotoxicity of CD19-CAR-NK92 cells is primarily mediated via perforin/granzyme pathway.

Chimeric antigen receptors (CARs) have improved cancer immunotherapy in recent years. Immune cells, such as Natural killer cells (NK-cells) or T cells, are used as effector cells in CAR-therapy. NK92-cells, a cell line with known cytotoxic activity, are of particular interest in CAR-therapy since culturing conditions are simple and anti-tumor efficacy combined with a manageable safety profile was proven in clinical trials. The major pathways of immune effector cells, including NK92-cells, to mediate cytotoxicity, are the perforin/granzyme and the death-receptor pathway. Detailed knowledge of CAR-effector cells' cytotoxic mechanisms is essential to unravel resistance mechanisms, which potentially arise by resistance against apoptosis-inducing signaling. Since mutations in apoptosis pathways are frequent in lymphoma, the impact on CAR-mediated cytotoxicity is of clinical interest. In this study, knockout models of CD19-CAR-NK92 cells were designed, to investigate cytotoxic pathways in vitro. Knockout of perforin 1 (Prf1) and subsequent abrogation of the perforin/granzyme pathway dramatically reduced the cytotoxicity of CD19-CAR-NK92 cells. In contrast, knockout of FasL and inhibition of TRAIL (tumor necrosis factor-related apoptosis-inducing ligands) did not impair cytotoxicity in most conditions. In conclusion, these results indicate the perforin/granzyme pathway as the major pathway to mediate cytotoxicity in CD19-CAR-NK92 cells.

Ars2-containing bispecific, Fab- and IgG1-format BAR-bodies to target DLBCL cells.

Despite recent advances in the therapy of diffuse large B-cell lymphoma, not otherwise specified (DLBCL), around 30% of patients develop refractory disease or relapse after first-line treatment. Recently, Ars2 was reported as the auto-antigenic target of the B-cell receptor (BCR) in approximately 25% of activated B-cell DLBCL cases. Ars2 could be used to specifically target B cells expressing Ars2-reactive BCRs. However, the optimal therapeutic format to integrate Ars2 into has yet to be determined. To mimic therapeutic antibody formats, Ars2-containing bispecific and IgG1-like constructs (BCR antigens for reverse [BAR]-bodies) were developed. Two bispecific BAR-bodies connecting single-chain antibodies against CD16 or CD3 to the BCR-binding epitope of Ars2 were constructed. Both constructs showed strong binding to U2932 cells and induced effector cell-dependent and selective cytotoxicity against U2932 cells of up to 44% at concentrations of 20 µg/ml. Additionally, IgG1-format Ars2 BAR-bodies were constructed by replacing the variable heavy- and light-chain regions of a full-length antibody with the Ars2 epitope. IgG1-format Ars2 BAR-bodies also bound selectively to U2932 and OCI-Ly3 cells and induced selective cytotoxicity of up to 60% at 10 µg/ml. In conclusion, Ars2-containing bispecific and IgG1-format BAR-bodies both are new therapeutic formats to target DLBCL cells.

Patient reported outcome measures in Waldenström macroglobulinaemia: A real-world data analysis from the WMUK Rory Morrison Registry.

Waldenström macroglobulinaemia (WM) is an incurable chronic B-cell malignancy, but highly responsive to treatment. Treatments include fixed-duration chemotherapy and continuous oral chemoimmunotherapy. In this expanding field, it is important to have reliable information on the impact of the various therapies on patients' quality of life (QoL). Patient reported outcome measures (PROMs) are increasingly recognised as important to understand patient experience of disease beyond traditional clinical outcome measures. Four QoL questionnaires (EORTC QLQ-C30 [European Organisation for Research and Treatment of Cancer quality of life core questionnaire], BIPQ [Brief Illness Perception Questionnaire], HADS [Hospital Anxiety and Depression Scale], EQ-5D-5L [EuroQoL 5-dimensional descriptive system questionnaire]) are embedded in the UK national WM registry, the Rory Morrison Registry. We reviewed the results from a snapshot of PROMs. As of November 2021, 155 patients completed PROM data with 98% completion rate across all 58 questions. Complete clinical information was available for 52 patients. The majority of QoL questions (69%) failed to elicit a notable median response. Only four questions elicited statistically significant responses when comparing groups, and these were exclusively found in the EuroQoL-5D-5L and HADS questionnaires. Our data suggest that widely used questionnaires may not be suitable for patients with WM. We advocate the development of WM-specific outcome measures to overcome this.

B-Cell Receptor Signaling and Beyond: The Role of Igα (CD79a)/Igß (CD79b) in Normal and Malignant B Cells.

B-cell receptor (BCR) is a B cell hallmark surface complex regulating multiple cellular processes in normal as well as malignant B cells. Igα (CD79a)/Igß (CD79b) are essential components of BCR that are indispensable for its functionality, signal initiation, and signal transduction. CD79a/CD79b-mediated BCR signaling is required for the survival of normal as well as malignant B cells via a wide signaling network. Recent studies identified the great complexity of this signaling network and revealed the emerging role of CD79a/CD79b in signal integration. In this review, we have focused on functional features of CD79a/CD79b, summarized signaling consequences of CD79a/CD79b post-translational modifications, and highlighted specifics of CD79a/CD79b interactions within BCR and related signaling cascades. We have reviewed the complex role of CD79a/CD79b in multiple aspects of normal B cell biology and how is the normal BCR signaling affected by lymphoid neoplasms associated CD79A/CD79B mutations. We have also summarized important unresolved questions and highlighted issues that remain to be explored for better understanding of CD79a/CD79b-mediated signal transduction and the eventual identification of additional therapeutically targetable BCR signaling vulnerabilities.

Humoral Immune Responses after an Omicron-Adapted Booster BNT162b2 Vaccination in Patients with Lymphoid Malignancies.

To accommodate waning COVID-19 vaccine immunity to emerging SARS-CoV-2 variants, variant-adapted mRNA vaccines have been introduced. Here, we examine serological responses to the BA.1 and BA.4-5 Omicron variant-adapted BNT162b2 COVID-19 vaccines in people with lymphoid malignancies. We included 233 patients with lymphoid malignancies (chronic lymphocytic B-cell leukemia: 73 (31.3%), lymphoma: 89 (38.2%), multiple myeloma/amyloidosis: 71 (30.5%)), who received an Omicron-adapted mRNA-based COVID-19 vaccine. IgG and neutralizing antibodies specific for the receptor-binding domain (RBD) of SARS-CoV-2 were measured using ELISA-based methods. Differences in antibody concentrations and neutralizing capacity and associations with risk factors were assessed using mixed-effects models. Over the period of vaccination with an Omicron-adapted COVID-19 vaccine, the predicted mean concentration of anti-RBD IgG increased by 0.09 log10 AU/mL/month (95% CI: 0.07; 0.11) in patients with lymphoid malignancies across diagnoses. The predicted mean neutralizing capacity increased by 0.9 percent points/month (95% CI: 0.2; 1.6). We found no associations between the increase in antibody concentration or neutralizing capacity and the variant included in the adapted vaccine. In conclusion, a discrete increase in antibody concentrations and neutralizing capacity was found over the course of Omicron-adapted vaccination in patients with lymphoid malignancies regardless of the adapted vaccine variant, indicating a beneficial effect of Omicron-adapted booster vaccination in this population.

Butyrate-producing Eubacterium rectale suppresses lymphomagenesis by alleviating the TNF-induced TLR4/MyD88/NF-κB axis.

Microbiota-induced tumorigenesis is well established in solid tumors of the gastrointestinal tract but rarely explored in hematologic malignancies. To determine the role of gut microbiota in lymphoma progression, we performed metagenomic sequencing on human primary gastrointestinal B cell lymphomas. We identified a distinct microbiota profile of intestinal lymphoma, with significantly decreased symbiotic microbes, particularly the genus Eubacterium and notably butyrate-producing Eubacterium rectale. Transfer of E. rectale-deficit microbiota of intestinal lymphoma patients to mice caused inflammation and tumor necrosis factor (TNF) production. Conversely, E. rectale treatment reduced TNF levels and the incidence of lymphoma in sensitized Eµ-Myc mice. Moreover, lipopolysaccharide from the resident microbiota of lymphoma patients and mice synergizes with TNF signaling and reinforces the NF-κB pathway via the MyD88-dependent TLR4 signaling, amalgamating in enhanced intestinal B cell survival and proliferation. These findings reveal a mechanism of inflammation-associated lymphomagenesis and a potential clinical rationale for therapeutic targeting of gut microbiota.

LGL leukemia patients exhibit substantial protective humoral responses following SARS-CoV-2 vaccination.

Large granular lymphocyte leukemia is a rare chronic lymphoproliferative disorder of cytotoxic cells. Other hematological malignancies such as CLL and multiple myeloma have been associated with poor vaccination response and markedly increased severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mortality rates, specifically in patients who have undergone immunosuppressive therapy. Given the immunosuppressive therapies often used to treat the disease, large granular lymphocytic (LGL) patients may be especially vulnerable to SARS-CoV-2 infection. A questionnaire was sent to all patients in the LGL Leukemia Registry at the University of Virginia (UVA) to obtain information on vaccination status, type of vaccine received, side effects of vaccination, patient treatment status before, during, and after vaccination, antibody testing, history of coronavirus disease 2019 (COVID-19) infection, and presence or absence of booster vaccination. Antibody testing of 27 patients who had quantitative SARS-CoV-2 Spike Protein IgG levels determined by University of Virginia medical laboratories via the Abbott Architect SARS-CoV-2 IgG II assay were collected. The assay was scored as reactive at a threshold of ≥50.0 AU/mL or nonreactive with a threshold of <50.0 AU/mL. LGL patients without treatment as well as patients who held treatment prior to their vaccination have a robust humoral response to SARS-CoV-2 vaccines. Patients who did not hold their immunosuppressive treatments have signifigantly diminished vaccine response compared to those who held their immunosuppressive treatment. Our findings support a dual strategy of pausing immunotherapy during the vaccination window and administration of the SARS-CoV-2 booster to all LGL leukemia patients to maximize protective antibodies.