TIM-3+ CD8 T cells with a terminally exhausted phenotype retain functional capacity in hematological malignancies

Chronic antigen stimulation is thought to generate dysfunctional CD8 T cells. Here, we identify a CD8 T cell subset in the bone marrow tumor microenvironment that, despite an apparent terminally exhausted phenotype (TPHEX), expressed granzymes, perforin, and IFN-γ. Concurrent gene expression and DNA accessibility revealed that genes encoding these functional proteins correlated with BATF expression and motif accessibility. IFN-γ+ TPHEX effectively killed myeloma with comparable efficacy to transitory effectors, and disease progression correlated with numerical deficits in IFN-γ+ TPHEX. We also observed IFN-γ+ TPHEX within CD19-targeted chimeric antigen receptor T cells, which killed CD19+ leukemia cells. An IFN-γ+ TPHEX gene signature was recapitulated in TEX cells from human cancers, including myeloma and lymphoma. Here, we characterize a TEX subset in hematological malignancies that paradoxically retains function and is distinct from dysfunctional TEX found in chronic viral infections. Thus, IFN-γ+ TPHEX represent a potential target for immunotherapy of blood cancers.

Immune status and selection of patients for immunotherapy in myeloma: a Proposal

Newer immune-based approaches based on recruitment and redirection of endogenous and/or synthetic immunity such as chimeric antigen-receptor-T (CAR-T) cells or bispecific antibodies are transforming the clinical management of multiple myeloma (MM). Contributions of the immune system to the anti-tumor effects of myeloma therapies are also increasingly appreciated. Clinical malignancy in MM originates in the setting of systemic immune alterations that begin early in myelomagenesis and regional changes in immunity impacted by spatial contexture. Pre-existing and therapy-induced changes in immune cells correlate with outcomes in MM patients including following immune therapies. Here we discuss insights from and limitation of current data about immune status and outcomes following immune therapies in MM patients. Pre-existing variation in systemic and/or regional immunity is emerging as a major determinant of the efficacy of current immune therapies as well as vaccines. MM is however a multifocal malignancy. As with solid tumors, integrating spatial aspects of the tumor and consideration of immune targets with biology of immune cells may be critical to optimize the application of immune therapy including T cell redirection in MM. We propose 5 distinct spatial immune types of MM- immune-depleted, immune-permissive, immune-excluded, immune-suppressed, and immune-resistant, that may provide an initial framework for optimal application of specific immune therapies in MM. Such considerations may also help optimize rational patient selection for emerging immune therapies to improve outcomes.

Immune-Pathogenesis of Myeloma

This research indicates that monoclonal gammopathy of undetermined significance (MGUS) and myeloma may stem from chronic immune activation and inflammation, causing immune dysfunction and spatial immune exclusion. As the conditions progress, a shift toward myeloma involves ongoing immune impairment, affecting both innate and adaptive immunity. Intriguingly, even in advanced myeloma stages, susceptibility to immune effector cells persists. This insight highlights the intricate interplay between immune responses and the development of these conditions, paving the way for potential therapeutic interventions targeting immune modulation in the management of MGUS and myeloma.

SARS-CoV-2 vaccination in the first year after hematopoietic cell transplant or chimeric antigen receptor T cell therapy: A prospective, multicenter, observational study (BMT CTN 2101)

Background

The optimal timing of vaccination with SARS-CoV-2 vaccines after cellular therapy is incompletely understood.

Objective

To describe humoral and cellular responses after SARS-CoV-2 vaccination initiated <4 months versus 4-12 months after cellular therapy.

Design

Multicenter prospective observational study.

Setting

34 centers in the United States.

Participants

466 allogeneic hematopoietic cell transplant (HCT; n=231), autologous HCT (n=170), or chimeric antigen receptor T cell (CAR-T cell) therapy (n=65) recipients enrolled between April 2021 and June 2022.

Interventions

SARS-CoV-2 vaccination as part of routine care.

Measurements

We obtained blood prior to and after vaccinations at up to five time points and tested for SARS-CoV-2 spike (anti-S) IgG in all participants and neutralizing antibodies for Wuhan D614G, Delta B.1.617.2, and Omicron B.1.1.529 strains, as well as SARS-CoV-2-specific T cell receptors (TCRs), in a subgroup.

Results

Anti-S IgG and neutralizing antibody responses increased with vaccination in HCT recipients irrespective of vaccine initiation timing but were unchanged in CAR-T cell recipients initiating vaccines within 4 months. Anti-S IgG ≥2,500 U/mL was correlated with high neutralizing antibody titers and attained by the last time point in 70%, 69%, and 34% of allogeneic HCT, autologous HCT, and CAR-T cell recipients, respectively. SARS-CoV-2-specific T cell responses were attained in 57%, 83%, and 58%, respectively. Humoral and cellular responses did not significantly differ among participants initiating vaccinations <4 months vs 4-12 months after cellular therapy. Pre-cellular therapy SARS-CoV-2 infection or vaccination were key predictors of post-cellular therapy anti-S IgG levels.

Limitations

The majority of participants were adults and received mRNA vaccines.

Conclusions

These data support starting mRNA SARS-CoV-2 vaccination three to four months after allogeneic HCT, autologous HCT, and CAR-T cell therapy.

Funding

National Marrow Donor Program, Leukemia and Lymphoma Society, Multiple Myeloma Research Foundation, Novartis, LabCorp, American Society for Transplantation and Cellular Therapy, Adaptive Biotechnologies, and the National Institutes of Health.

Role of Natural Killer T (NKT) Cells in Myeloma Biology and Therapy

Natural Killer T (NKT) cells are distinct innate lymphocytes that recognize lipid antigens in the context of nonpolymorphic molecule CD1d. Multiple myeloma (MM) is a hematologic malignancy wherein malignant plasma cells express CD1d and are sensitive to lysis by NKT cells. Progressive malignancy in MM is characterized by NKT cell dysfunction. Several studies have tried to harness the anti-tumor properties of NKT cells in MM to mediate tumor regression. NKT cells are also attractive targets for approaches at immune redirection in MM with chimeric-antigen receptor NKT (CAR-NKT) and bispecific antibodies. In addition to the commonly studied invariant-NKT (iNKT) cells, MM patients often also exhibit alterations in type-II NKT cells and their ligands. In patients and mouse models with Gaucher disease (GD), an inherited lipid-storage disorder with markedly increased risk for MM, distinct type-II NKT cells exhibit a T-follicular helper (NKT-TFH) phenotype and provide help to lipid-specific B cells. Chronic immune activation in this setting eventually sets the stage for malignancy, which can be targeted in both mouse models and GD patients by reducing the underlying antigen. NKT cells are thus integrally linked to MM pathogenesis and an attractive target for MM immunotherapy.

BA.5 bivalent booster vaccination enhances neutralization of XBB.1.5, XBB.1.16 and XBB.1.9 variants in patients with lung cancer

This study reports that most patients with NSCLC had a significant increase in the nAb response to the currently circulating Omicron variants after bivalent booster vaccination and had Ab titers comparable to healthy participants. Interestingly, though the durability of the nAb response persisted in most of the healthy participants, patients with NSCLC had significantly reduced nAb titers after 4-6 months of vaccination. Our data highlight the importance of COVID-19 bivalent booster vaccination as the standard of care for patients with NSCLC given the evolution of new variants of concern.

Rapid, high throughput, automated detection of SARS-CoV-2 neutralizing antibodies against Wuhan-WT, delta and omicron BA1, BA2 spike trimers

Traditional cellular and live-virus methods for detection of SARS-CoV-2 neutralizing antibodies (nAbs) are labor- and time-intensive, and thus not suited for routine use in the clinical lab to predict vaccine efficacy and natural immune protection. Here, we report the development and validation of a rapid, high throughput method for measuring SARS-CoV-2 nAbs against native-like trimeric spike proteins. This assay uses a blockade of human angiotensin converting enzyme 2 (hACE-2) binding (BoAb) approach in an automated digital immunoassay on the Quanterix HD-X platform. BoAb assays using Wuhan-WT (vaccine strain), delta (B.1.167.2), omicron BA1 and BA2 variant viral strains showed strong correlation with cell-based pseudovirus neutralization activity (PNA) and live-virus neutralization activity. Importantly, we were able to detect similar patterns of delta and omicron variant resistance to neutralization in samples with paired vaccine strain and delta variant BoAb measurements. Finally, we screened clinical samples from patients with or without evidence of SARS-CoV-2 exposure by a single-dilution screening version of our assays, finding significant nAb activity only in exposed individuals. Importantly, this completely automated assay can be performed in 4 h to measure neutralizing antibody titers for 16 samples over 8 serial dilutions or, 128 samples at a single dilution with replicates. In principle, these assays offer a rapid, robust, and scalable alternative to time-, skill-, and cost-intensive standard methods for measuring SARS-CoV-2 nAb levels.

Harnessing Dendritic Cells: Next Frontier for Durable Immune Control in Myeloma

Immune-based approaches including T-cell redirection have transformed the therapeutic landscape in myeloma. Injection of dendritic cells (DC) led to the induction of immune responses in vaccinated patients with myeloma. These studies pave the way for future combination strategies harnessing DCs to enhance tumor immunity and improve outcomes in myeloma. See related article by Freeman et al., p. 4575.

Trans-vaccenic acid reprograms CD8+ T cells and anti-tumour immunity

Diet-derived nutrients are inextricably linked to human physiology by providing energy and biosynthetic building blocks and by functioning as regulatory molecules. However, the mechanisms by which circulating nutrients in the human body influence specific physiological processes remain largely unknown. Here we use a blood nutrient compound library-based screening approach to demonstrate that dietary trans-vaccenic acid (TVA) directly promotes effector CD8+ T cell function and anti-tumour immunity in vivo. TVA is the predominant form of trans-fatty acids enriched in human milk, but the human body cannot produce TVA endogenously1. Circulating TVA in humans is mainly from ruminant-derived foods including beef, lamb and dairy products such as milk and butter2,3, but only around 19% or 12% of dietary TVA is converted to rumenic acid by humans or mice, respectively4,5. Mechanistically, TVA inactivates the cell-surface receptor GPR43, an immunomodulatory G protein-coupled receptor activated by its short-chain fatty acid ligands6-8. TVA thus antagonizes the short-chain fatty acid agonists of GPR43, leading to activation of the cAMP-PKA-CREB axis for enhanced CD8+ T cell function. These findings reveal that diet-derived TVA represents a mechanism for host-extrinsic reprogramming of CD8+ T cells as opposed to the intrahost gut microbiota-derived short-chain fatty acids. TVA thus has translational potential for the treatment of tumours.

Divergence of variant binding/neutralizing antibodies following SARS-CoV-2 booster vaccines in myeloma: Impact of hybrid immunity

We characterized virus-neutralization and spike-binding antibody profiles in myeloma patients following monovalent or bivalent-SARS-CoV-2 booster vaccination. Vaccination improves the breadth of binding antibodies but not neutralization activity against current variants. Hybrid immunity and immune imprinting impact vaccine-elicited immunity.

Role of B cells in immune-related adverse events following checkpoint blockade

Blockade of immune checkpoints has transformed the therapy of several cancers. However, immune-related adverse events (irAEs) have emerged as a major challenge limiting the clinical application of this approach. B cells are recognized as major players in the pathogenesis of human autoimmunity and have been successfully targeted to treat these disorders. While T cells have been extensively studied as therapeutic targets of immune checkpoint blockade (ICB), these checkpoints also impact B cell tolerance. Blockade of immune checkpoints in the clinic is associated with distinct changes in the B cell compartment that correlate with the development of irAEs. In this review, we focus on the possible role of humoral immunity, specifically human B cell subsets and autoantibodies in the pathogenesis of ICB-induced irAEs. There remains an unmet need to better understand the T:B cell cross talk underlying the activation of pathogenic B cells and the development of ICB-induced irAEs. Such studies may identify new targets or approaches to prevent or treat irAEs and improve the application of ICB therapy in cancer.

Divergence of variant binding/neutralizing antibodies following SARS-CoV-2 booster vaccines in myeloma: Impact of hybrid immunity

We characterized virus-neutralization and spike-binding antibody profiles in myeloma patients following monovalent or bivalent-SARS-CoV-2 booster vaccination. Vaccination improves the breadth of binding antibodies but not neutralization activity against current variants. Hybrid immunity and immune imprinting impact vaccine-elicited immunity.

Regulation of antigen-specific T cell infiltration and spatial architecture in multiple myeloma and premalignancy

Entry of antigen-specific T cells into human tumors is critical for immunotherapy, but the underlying mechanisms are poorly understood. Here, we combined high-dimensional spatial analyses with in vitro and in vivo modeling to study the mechanisms underlying immune infiltration in human multiple myeloma (MM) and its precursor monoclonal gammopathy of undetermined significance (MGUS). Clustered tumor growth was a feature of MM but not MGUS biopsies, and this growth pattern was reproduced in humanized mouse models. MM biopsies exhibited intralesional as well as spatial heterogeneity, with coexistence of T cell-rich and T cell-sparse regions and the presence of areas of T cell exclusion. In vitro studies demonstrated that T cell entry into MM clusters was regulated by agonistic signals and CD2-CD58 interactions. Upon adoptive transfer, antigen-specific T cells localized to the tumor site but required in situ DC-mediated antigen presentation for tumor entry. C-type lectin domain family 9 member A-positive (CLEC9A+) DCs appeared to mark portals of entry for gradients of T cell infiltration in MM biopsies, and their proximity to T cell factor 1-positive (TCF1+) T cells correlated with disease state and risk status. These data illustrate a role for tumor-associated DCs and in situ activation in promoting the infiltration of antigen-specific T cells in MM and provide insights into spatial alterations in tumor/immune cells with malignant evolution.

SARS-CoV-2 vaccination in the first year after allogeneic hematopoietic cell transplant: a prospective, multicentre, observational study

Background

The optimal timing for SARS-CoV-2 vaccines within the first year after allogeneic hematopoietic cell transplant (HCT) is poorly understood.

Methods

We conducted a prospective, multicentre, observational study of allogeneic HCT recipients who initiated SARS-CoV-2 vaccinations within 12 months of HCT. Participants were enrolled at 22 academic cancer centers across the United States. Participants of any age who were planning to receive a first post-HCT SARS-CoV-2 vaccine within 12 months of HCT were eligible. We obtained blood prior to and after each vaccine dose for up to four vaccine doses, with an end-of-study sample seven to nine months after enrollment. We tested for SARS-CoV-2 spike protein (anti-S) IgG; nucleocapsid protein (anti-N) IgG; neutralizing antibodies for Wuhan D614G, Delta B.1.617.2, and Omicron B.1.1.529 strains; and SARS-CoV-2-specific T-cell receptors (TCRs). The primary outcome was a comparison of anti-S IgG titers at the post-V2 time point in participants initiating vaccinations <4 months versus 4-12 months after HCT using a propensity-adjusted analysis. We also evaluated factors associated with high-level anti-S IgG titers (≥2403 U/mL) in logistic regression models.

Findings

Between April 22, 2021 and November 17, 2021, 175 allogeneic HCT recipients were enrolled in the study, of whom all but one received mRNA SARS-CoV-2 vaccines. SARS-CoV-2 anti-S IgG titers, neutralizing antibody titers, and TCR breadth and depth did not significantly differ at all tested time points following the second vaccination among those initiating vaccinations <4 months versus 4-12 months after HCT. Anti-S IgG ≥2403 U/mL correlated with neutralizing antibody levels similar to those observed in a prior study of non-immunocompromised individuals, and 57% of participants achieved anti-S IgG ≥2403 U/mL at the end-of-study time point. In models adjusted for SARS-CoV-2 infection pre-enrollment, SARS-CoV-2 vaccination pre-HCT, CD19+ B-cell count, CD4+ T-cell count, and age (as applicable to the model), vaccine initiation timing was not associated with high-level anti-S IgG titers at the post-V2, post-V3, or end-of-study time points. Notably, prior graft-versus-host-disease (GVHD) or use of immunosuppressive medications were not associated with high-level anti-S IgG titers. Grade ≥3 vaccine-associated adverse events were infrequent.

Interpretation

These data support starting mRNA SARS-CoV-2 vaccination three months after HCT, irrespective of concurrent GVHD or use of immunosuppressive medications. This is one of the largest prospective analyses of vaccination for any pathogen within the first year after allogeneic HCT and supports current guidelines for SARS-CoV-2 vaccination starting three months post-HCT. Additionally, there are few studies of mRNA vaccine formulations for other pathogens in HCT recipients, and these data provide encouraging proof-of-concept for the utility of early vaccination targeting additional pathogens with mRNA vaccine platforms.

Funding

National Marrow Donor Program, Leukemia and Lymphoma Society, Multiple Myeloma Research Foundation, Novartis, LabCorp, American Society for Transplantation and Cellular Therapy, Adaptive Biotechnologies, and the National Institutes of Health.

BCMA CAR-T induces complete and durable remission in refractory plasmablastic lymphoma

Plasmablastic lymphoma (PBL) is a rare subtype of aggressive large B-cell lymphoma, with a dismal prognosis despite aggressive therapies. New approaches are needed for those with refractory disease. PBL expresses antigens similar to multiple myeloma (MM), including B-cell maturation antigen (BCMA). Chimeric antigen receptor T-cell (CAR-T) therapy directed against BCMA has shown efficacy for the treatment of heavily pretreated MM with low rates of grades 3 and 4 cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) in a phase Ib/II trial (A Study of JNJ-68284528, a CAR-T Directed Against BCMA in Participants With Relapsed or Refractory Multiple Myeloma (CARTITUDE-1), NCT03548207). However, data for the use of BCMA CAR-T for treating PBL are lacking.We report a challenging case of multiple refractory PBL that emerged from B-cell acute lymphoblastic leukemia in an adolescent who failed to respond to an allogeneic hematopoietic cell transplant. The patient developed rapidly advancing disease despite withdrawal of immunosuppression, treatment with etoposide, ibrutinib, and daratumumab, prompting consideration of BCMA CAR-T (under emergency investigational new drug (eIND)). The patient achieved a complete remission (CR), without recurrent acute graft versus host disease (GVHD), CRS or ICANS after BCMA CAR-T therapy. BCMA CAR-T expansion was detected in vivo, peaking on day 15. The patient remains in CR for more than a year post CAR-T therapy, supporting consideration of immunotherapy for future patients with refractory PBL, a disease with few treatment options.

Immune Reconstitution and Vaccinations in Multiple Myeloma: A Report From the 19th International Myeloma Society Annual Workshop

Given the significance of the immune system and the important role of therapies within the context of the immune system in plasma cell disorders, the International Myeloma Society annual workshop convened a session dedicated to this topic. A panel of experts covered various aspects of immune reconstitution and vaccination. The top oral presentations were highlighted and discussed. This is a report of the proceedings.

Impaired SARS-CoV-2 Variant Neutralization and CD8+ T-cell Responses Following 3 Doses of mRNA Vaccines in Myeloma: Correlation with Breakthrough Infections

Patients with multiple myeloma (MM) mount suboptimal neutralizing antibodies (nAb) following 2 doses of SARS-CoV-2 mRNA vaccines. Currently, circulating SARS-CoV-2 variants of concern (VOC) carry the risk of breakthrough infections. We evaluated immune recognition of current VOC including BA.1, BA.2, and BA.5 in 331 racially representative patients with MM following 2 or 3 doses of mRNA vaccines. The third dose increased nAbs against WA1 in 82%, but against BA variants in only 33% to 44% of patients. Vaccine-induced nAbs correlated with receptor-binding domain (RBD)-specific class-switched memory B cells. Vaccine-induced spike-specific T cells were detected in patients without seroconversion and cross-recognized variant-specific peptides but were predominantly CD4+ T cells. Detailed clinical/immunophenotypic analysis identified features correlating with nAb/B/T-cell responses. Patients who developed breakthrough infections following 3 vaccine doses had lower live-virus nAbs, including against VOC. Patients with MM remain susceptible to SARS-CoV-2 variants following 3 vaccine doses and should be prioritized for emerging approaches to elicit variant-nAb and CD8+ T cells.

SIGNIFICANCE

Three doses of SARS-CoV-2 mRNA vaccines fail to yield detectable VOC nAbs in nearly 60% and spike-specific CD8+ T cells in >80% of myeloma patients. Patients who develop breakthrough infections following vaccination have low levels of live-virus nAb. This article is highlighted in the In This Issue feature, p. 101.

The immune system in multiple myeloma and precursor states: Lessons and implications for immunotherapy and interception

Multiple myeloma (MM) and its precursor monoclonal gammopathy of undetermined significance (MGUS) are distinct disorders that likely originate in the setting of chronic immune activation. Evolution of these lesions is impacted by cross-talk with both innate and adaptive immune systems of the host. Harnessing the immune system may, therefore, be an attractive strategy to prevent clinical malignancy. While clinical MM is characterized by both regional and systemic immune suppression and paresis, immune-based approaches, particularly redirecting T cells have shown remarkable efficacy in MM patients. Optimal application and sequencing of these new immune therapies and their integration into clinical MM management may depend on the underlying immune status, in turn impacted by host, tumor, and environmental features. Immune therapies carry the potential to achieve durable unmaintained responses and cures in MM.

Cross center single-cell RNA sequencing study of the immune microenvironment in rapid progressing multiple myeloma

Despite advancements in understanding the pathophysiology of Multiple Myeloma (MM), the cause of rapid progressing disease in a subset of patients is still unclear. MM's progression is facilitated by complex interactions with the surrounding bone marrow (BM) cells, forming a microenvironment that supports tumor growth and drug resistance. Understanding the immune microenvironment is key to identifying factors that promote rapid progression of MM. To accomplish this, we performed a multi-center single-cell RNA sequencing (scRNA-seq) study on 102,207 cells from 48 CD138^- BM samples collected at the time of disease diagnosis from 18 patients with either rapid progressing (progression-free survival (PFS) < 18 months) or non-progressing (PFS > 4 years) disease. Comparative analysis of data from three centers demonstrated similar transcriptome profiles and cell type distributions, indicating subtle technical variation in scRNA-seq, opening avenues for an expanded multicenter trial. Rapid progressors depicted significantly higher enrichment of GZMK⁺ and TIGIT⁺ exhausted CD8⁺ T-cells (P = 0.022) along with decreased expression of cytolytic markers (PRF1, GZMB, GNLY). We also observed a significantly higher enrichment of M2 tolerogenic macrophages in rapid progressors and activation of pro-proliferative signaling pathways, such as BAFF, CCL, and IL16. On the other hand, non-progressive patients depicted higher enrichment for immature B Cells (i.e., Pre/Pro B cells), with elevated expression for markers of B cell development (IGLL1, SOX4, DNTT). This multi-center study identifies the enrichment of various pro-tumorigenic cell populations and pathways in those with rapid progressing disease and further validates the robustness of scRNA-seq data generated at different study centers.

Antibody binding and neutralization of live SARS-CoV-2 variants including BA.4/5 following booster vaccination of patients with B-cell malignancies

Non-Hodgkin lymphoma and chronic lymphocytic leukemia (NHL/CLL) patients elicit inadequate antibody responses after initial SARS-CoV-2 vaccination and remain at high risk of severe COVID-19 disease. We investigated IgG, IgA, and IgM responses after booster vaccination against recent SARS-CoV-2 variants including Omicron BA.5 in 67 patients. Patients had lower fold increase and total anti-spike binding titers after booster than healthy individuals. Antibody responses negatively correlated with recent anti-CD20 therapy and low B cell numbers. Antibodies generated after booster demonstrated similar binding properties against SARS-CoV-2 variants compared to those generated by healthy controls with lower binding against Omicron variants. Importantly, 43% of patients showed anti-Omicron BA.1 neutralizing antibodies after booster and all these patients also had anti-Omicron BA.5 neutralizing antibodies. NHL/CLL patients demonstrated inferior antibody responses after booster vaccination, particularly against Omicron variants. Prioritization of prophylactic and treatment agents and vaccination of patients and close contacts with updated vaccine formulations are essential.

Antibody Response to COVID-19 mRNA Vaccine in Patients With Lung Cancer After Primary Immunization and Booster: Reactivity to the SARS-CoV-2 WT Virus and Omicron Variant

PURPOSE

To examine COVID-19 mRNA vaccine-induced binding and neutralizing antibody responses in patients with non-small-cell lung cancer (NSCLC) to SARS-CoV-2 614D (wild type [WT]) strain and variants of concern after the primary 2-dose and booster vaccination.

METHODS

Eighty-two patients with NSCLC and 53 healthy volunteers who received SARS-CoV-2 mRNA vaccines were included in the study. Blood was collected longitudinally, and SARS-CoV-2-specific binding and neutralizing antibody responses were evaluated by Meso Scale Discovery assay and live virus Focus Reduction Neutralization Assay, respectively.

RESULTS

A majority of patients with NSCLC generated binding and neutralizing antibody titers comparable with the healthy vaccinees after mRNA vaccination, but a subset of patients with NSCLC (25%) made poor responses, resulting in overall lower (six- to seven-fold) titers compared with the healthy cohort (P = < .0001). Although patients age > 70 years had lower immunoglobulin G titers (P = < .01), patients receiving programmed death-1 monotherapy, chemotherapy, or a combination of both did not have a significant impact on the antibody response. Neutralizing antibody titers to the B.1.617.2 (Delta), B.1.351 (Beta), and in particular, B.1.1.529 (Omicron) variants were significantly lower (P = < .0001) compared with the 614D (WT) strain. Booster vaccination led to a significant increase (P = .0001) in the binding and neutralizing antibody titers to the WT and Omicron variant. However, 2-4 months after the booster, we observed a five- to seven-fold decrease in neutralizing titers to WT and Omicron viruses.

CONCLUSION

A subset of patients with NSCLC responded poorly to the SARS-CoV-2 mRNA vaccination and had low neutralizing antibodies to the B.1.1.529 Omicron variant. Booster vaccination increased binding and neutralizing antibody titers to Omicron, but antibody titers declined after 3 months. These data highlight the concern for patients with cancer given the rapid spread of SARS-CoV-2 Omicron variant.

Changes in Bone Marrow Tumor and Immune Cells Correlate with Durability of Remissions Following BCMA CAR T Therapy in Myeloma

Chimeric antigen-receptor (CAR) T cells lead to high response rates in myeloma, but most patients experience recurrent disease. We combined several high-dimensional approaches to study tumor/immune cells in the tumor microenvironment (TME) of myeloma patients pre- and post-B-cell maturation antigen (BCMA)-specific CAR T therapy. Lower diversity of pretherapy T-cell receptor (TCR) repertoire, presence of hyperexpanded clones with exhaustion phenotype, and BAFF+PD-L1+ myeloid cells in the marrow correlated with shorter progression-free survival (PFS) following CAR T therapy. In contrast, longer PFS was associated with an increased proportion of CLEC9A+ dendritic cells (DC), CD27+TCF1+ T cells with diverse T-cell receptors, and emergence of T cells expressing marrow-residence genes. Residual tumor cells at initial response express stemlike genes, and tumor recurrence was associated with the emergence of new dominant clones. These data illustrate a dynamic interplay between endogenous T, CAR T, myeloid/DC, and tumor compartments that affects the durability of response following CAR T therapy in myeloma.

SIGNIFICANCE

There is an unmet need to identify determinants of durable responses following BCMA CAR T therapy of myeloma. High-dimensional analysis of the TME was performed to identify features of immune and tumor cells that correlate with survival and suggest several strategies to improve outcomes following CAR T therapy. See related commentary by Graham and Maus, p. 478. This article is highlighted in the In This Issue feature, p. 476.

Humoral Responses Against SARS-CoV-2 and Variants of Concern After mRNA Vaccines in Patients With Non-Hodgkin Lymphoma and Chronic Lymphocytic Leukemia

PURPOSE

Patients with non-Hodgkin lymphoma including chronic lymphocytic leukemia (NHL/CLL) are at higher risk of severe SARS-CoV-2 infection. We investigated vaccine-induced antibody responses in patients with NHL/CLL against the original SARS-CoV-2 strain and variants of concern including B.1.167.2 (Delta) and B.1.1.529 (Omicron).

MATERIALS AND METHODS

Blood from 121 patients with NHL/CLL receiving two doses of vaccine were collected longitudinally. Antibody binding against the full-length spike protein, the receptor-binding, and N-terminal domains of the original strain and of variants was measured using a multiplex assay. Live-virus neutralization against Delta, Omicron, and the early WA1/2020 strains was measured using a focus reduction neutralization test. B cells were measured by flow cytometry. Correlation between vaccine response and clinical factors was determined.

RESULTS

Mean anti-SARS-CoV-2 spike immunoglobulin G-binding titers were 85-fold lower in patients with NHL/CLL compared with healthy controls, with seroconversion occurring in only 67% of patients. Neutralization titers were also lower and correlated with binding titers (P < .0001). Treatment with anti-CD20-directed therapies within 1 year resulted in 136-fold lower binding titers. Peripheral blood B-cell count also correlated with vaccine response. At 3 months from last anti-CD20-directed therapy, B-cell count ≥ 4.31/μL blood around the time of vaccination predicted response (OR 7.46, P = .04). Antibody responses also correlated with age. Importantly, neutralization titers against Delta and Omicron were reduced six- and 42-fold, respectively, with 67% of patients seropositive for WA1/2020 exhibiting seronegativity for Omicron.

CONCLUSION

Antibody binding and live-virus neutralization against SARS-CoV-2 and its variants of concern including Delta and Omicron were substantially lower in patients with NHL/CLL compared with healthy vaccinees. Anti-CD20-directed therapy < 1 year before vaccination and number of circulating B cells strongly predict vaccine response.

Comprehensive characterization of the multiple myeloma immune microenvironment using integrated scRNA-seq, CyTOF, and CITE-seq analysis

As part of the Multiple Myeloma Research Foundation (MMRF) immune atlas pilot project, we compared immune cells of Multiple Myeloma (MM) bone marrow samples from 18 patients assessed by single-cell RNA-seq (scRNA-seq), mass cytometry (CyTOF), and Cellular Indexing of Transcriptomes and Epitopes by Sequencing (CITE-seq) to understand the concordance of measurements among single-cell techniques. Cell type abundances are relatively consistent across the three approaches, while variations are observed in T cells, macrophages, and monocytes. Concordance and correlation analysis of cell type marker gene expression across different modalities highlighted the importance of choosing cell type marker genes best suited to particular modalities. By integrating data from these three assays, we found International Staging System (ISS) stage 3 patients exhibited decreased CD4+ T/ CD8+ T cells ratio. Moreover, we observed upregulation of RAC2 and PSMB9, in NK cells of fast progressors (FP) compared to those of non-progressors (NP), as revealed by both scRNA-seq and CITE-seq RNA measurement. This detailed examination of the immune microenvironment in MM using multiple single cell technologies revealed markers associated with MM rapid progression which will be further characterized by the full-scale immune atlas project.

Abstract 580: MM3 CAR T: A novel tumor targeting and T cell redirection platform for multiple myeloma

Novel strategies to target tumors are needed to enhance the efficacy of immune redirection therapies. The detection of tumors based on mammalian immunoglobulin scFvs has been a significant innovation in immunotherapy but is impacted by limits of immune tolerance and immune system evolution. The discovery of unique variable lymphocyte receptors (VLRs) - analogues to antibodies in evolutionarily distant jawless vertebrates - in the Cooper lab (Pancer, Nature) provides an opportunity to target antigens beyond those recognized by conventional antibodies. A particular VLR, termed MM3, was found to identify a distinct epitope specific to human plasma cells (PCs) and plasmablasts (PBs), created by CD38 dimerization with activity as an NAD+ glycohydrolase (Yu, JCI Insight). CD38 is an extensively explored target for treating multiple myeloma (MM); however, specific scFv-based targeting of CD38 on malignant plasma cells is difficult, as the protein is expressed on a variety of other immune cell lineages. Therefore, MM3 provides a unique, novel mechanism to target CD38 in a tumor-specific manner in MM and other plasma cell dyscrasias. Here, we present a CAR T cell with an MM3 binding domain replacing the standard scFv. Our CAR construct consists of the MM3 binding domain, a CD8 hinge and transmembrane domain, and 4-1BB and CD3zeta intracellular domains. Staining of MM patient bone marrow specimens revealed that the strong specificity for PCs and PBs previously observed in healthy donors was maintained in MM bone marrow, illustrating the ability of MM3 to target the malignant PC population. To assess in vitro function of the MM3 CAR T cells, flow cytometry analysis of co-cultures using healthy donor-derived MM3 CAR T cells and target cell lines revealed specific increased degranulation (CD107a expression), activation (CD69 expression), and killing (target cell Annexin V binding) over untransduced control T cells only in cell lines sensitive to MM3 binding, with no differences in negative control cell lines, demonstrating specific recognition and killing of target cells. Preliminary in vivo studies in the MISTRG6 myeloma xenograft mouse model were performed using intrafemorally injected INA-6, an IL-6-dependent MM cell line, which MM3 binds after growth in vivo. After treatment with MM3 CAR T cells via intravenous injection, we observed that the MM3 CAR T cells specifically homed to and were retained in the injected femur along with the tumor cells, suggesting tumor recognition and potential for in vivo efficacy. In summary, these data demonstrate that VLR-based targeting may allow design of novel CAR constructs. Specifically, the VLR MM3 is a promising novel, non-scFv mechanism for targeting CD38 in a malignant PC-specific manner, and the MM3 CAR T cells have shown promising preliminary activity. Therefore, the VLR-based MM3 CAR T cell platform may provide a novel strategy to improve T cell redirection to target tumors in MM.

Citation Format: Samuel S. McCachren, Julia Manalo, Katherine Pendleton, Mary E. Ballestas, Kavita M. Dhodapkar, Melissa L. Kemp, Max D. Cooper, Madhav V. Dhodapkar. MM3 CAR T: A novel tumor targeting and T cell redirection platform for multiple myeloma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 580.

Abstract 2825: Stromal cell derived IL6 inhibits the extrinsic apoptotic pathway in multiple myeloma cell lines

Multiple myeloma (MM) is a disease of malignant plasma cells that resides in the bone marrow microenvironment (BMM). While advances in therapy have improved patient outcomes, the majority of patients relapse. Clinical trials have shown that BCMA targeted CAR-T therapy induces MM remission in most patients with heavily pretreated relapsed refractory MM; however, the duration of the response has been disappointing. CAR-T cells induce target cell death through two primary mechanisms, granzyme B and FASL. To define the role of FAS-induced cell death in CAR-T therapy in MM, we first evaluated if FAS-induced cell death was important for CAR-T activity in MM. We utilized CRISPR-Cas9 to generate FAS KOs in three MM cell lines: RPMI8226, KMS18, and OCIMY5. These lines were utilized in vitro in cytotoxic CAR-T assays where MM cells were cultured with BMCA CAR-T cells at five effector to target (E:T) ratios (range: 0:1 to 1:1). The loss of FAS protected KMS18 and OCIMY5 from CAR-T induced cell death, changing the E:T ratio needed to induce 50% MM cell death 3.2 and 3.4 fold respectively, but did not protect RPMI8226. We determined the expression of FAS negatively correlated with the EC50 of rFASL, suggesting that FAS expression levels are important for this response. To determine the role of the intrinsic apoptotic pathway in FASL-induced death, we knocked out BAK and BAX in KMS12 PE and OCIMY5. This did not protect KMS12 PE or OCIMY5 from rFASL-induced cell death, suggesting that FAS uses the type I mitochondria-independent pathway in these cell lines. The BMM supports MM progression and promotes drug resistance in part by altering the apoptotic threshold. Therefore, we examined the impact of the BMM on FASL-induced cell death. Coculture of MM cells with the HS5 stromal cell line protected KSM12 PE and KMS18 from rFASL, with the EC50 of rFASL changing 2.72 and 3.1 fold respectively, but did not protect OCIMY5. To determine if the protection observed was cell contact dependent, or only required soluble factors, we utilized HS5 conditioned media (CM). HS5 CM protected KMS12 PE, KMS18, and surprisingly OCIMY5 from rFASL, causing a change in EC50 from control of 1.65 - 2.23 fold. CM lacking IL6 did not protect MM cells from rFASL. Therefore, we tested the effects of IL6 addition IL6(10 ng/ml) and observed protection from rFASL in KMS12 PE and KMS18 cells with a change in EC50 of 2.03 and 3.84 fold respectively; however, we did not see protection in OCIMY5. To identify the mechanism of IL6-induced resistance to rFASL, we cultured BAK/BAX KO cells in HS5 CM and observed protection of these apoptosis-deficient KMS12 PE and OCIMY5 cells from rFASL. This suggests that soluble factors in the BMM can convert cells from type I to type II (mitochondrial-dependent) death receptor signaling and that inhibiting BMM signals such as IL6 may enhance FASL-induced cell death in MM. However, the data also demonstrate that the role of FAS in CAR-T killing is cell context dependent.

Citation Format: James C. Ackley, Samuel McCachren, Sagar Lonial, Damien J. Green, Stanley R. Riddell, Geoffrey R. Hill, Madhav V. Dhodapkar, Lawrence H. Boise. Stromal cell derived IL6 inhibits the extrinsic apoptotic pathway in multiple myeloma cell lines [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2825.

Clinical features of patients with multiple myeloma harboring t(4;14) and impact on long-term survival

8062

Background: Translocation (4;14) is a known adverse prognostic factor in myeloma. However, utilization of proteasome inhibitors (PIs) in myeloma has abrogated the negative impact of t(4;14) in myeloma, and some investigators question whether t(4;14) still needs to be considered a high-risk marker. Here, we present a retrospective analysis of 142 patients with t(4;14) and describe disease characteristics, treatment patterns, and long-term outcomes. Methods: From January 2007 to August 2016, 42 patients with newly diagnosed myeloma and t(4;14) were identified. Demographics, clinical characteristics, and outcomes data for the patients were obtained from our institutional review board-approved myeloma database. Responses were evaluated per IMWG Uniform Response Criteria. Results: The median age of this cohort was 59.6 years (range 33-78). Notable patient characteristics include: W/AA/Asian 25.9%/23.6%/50%; ISS I/II/III 36.4%/22.9%/24.1%; R-ISS I/II/III 0%/27.8%/25.8%. Median lab values at diagnosis include: Hgb 10.4 g/dL, Hct 30.8%, Cr 1.01, and Ca 9.4, Frequency of concurrent cytogenetic abnormalities include del(17p): 19.7%; del(13): 44.4%, and +1q21: 46.5%. A majority of patients (86.7%) were induced with either triplet or quadruplet regimens, with 88% of these regimens including a proteasome inhibitor. 78.9% of patients underwent ASCT. Of those responses captured, 75.3% achieved ≥VGPR (sCR 4.8%, CR 30.5%, VGPR 40%, PR 20%). Post-transplant, 88% achieved ≥VGPR (sCR 35.1%, CR 30.9%, VGPR 22.3%), and 82% received maintenance therapy. The most common maintenance regimens included revlimid (34.8%), bortezomib (16.5%), and RVD (11.3%); one-third of patients received triplet maintenance regimens. With a median follow up of 99.5 months, the overall mPFS and mOS for this cohort of t(4;14) patients was 47.6 m (95% CI 32.3-62.8) and 108.5 months (95% CI 87.9-129.2). In patients with both t(4;14) and del(17p), the mPFS was 20.8 months and mOS was 89.6 months; for concurrent t(4;14) and +1q21, the mPFS was 32.0 months and 89.6 months. In patients that received maintenance therapy versus no maintenance, the mPFS and mOS was 54.9 months (95% CI 47.4-62.4) and 115.3 months (95% CI 96.3-134.3) versus 14.7 months (95% CI 13.1-16.3) and 34.3 months (95% CI 10.1-58.5), respectively. Conclusions: Overall, the prognosis of t(4;14) myeloma patients significantly improved compared to the pre-proteasome inhibitor era. In particular, maintenance therapies (predominantly PI- based) have made a clear survival impact (doubling of mPFS to 4.5 years and mOS to 9.5 years) compared to patients that did not receive maintenance therapy. However, presence of other concomitant cytogenetic abnormalities such as +1q21 and del(17p) continues to confer poorer outcomes, and innovative approaches are needed to obtain better outcomes for this subgroup of patients.

Updated survival with extended follow-up on patients with newly diagnosed multiple myeloma treated with lenalidomide, bortezomib, and dexamethasone (RVD) induction therapy and a risk-stratified maintenance approach

8061

Background: Lenalidomide, bortezomib, and dexamethasone (RVD) has been established as an effective and well-tolerated induction regimen in patients with newly diagnosed myeloma (NDMM). We have previously published a retrospective analysis of 1000 patients treated with RVD and risk-stratified maintenance therapy showing a median PFS of 65 months and median OS of 126 months for the entire cohort (Joseph et al, JCO 2020). This data has served as an important benchmark for evaluating upfront treatment strategies in NDMM. Here, we present updated survival data with extended follow up on this patient population treated at the Winship Cancer Institute of Emory University. Methods: From January 2007 to August 2016, 1000 consecutive newly diagnosed myeloma patients treated with RVD induction therapy (R-25 mg/day on days 1-14, V-1.3 mg/m2 on days 1,4,8,11 and D-40 mg once/twice weekly as tolerated) were identified. Demographics, clinical characteristics, and outcomes data for the patients were obtained from our institutional review board-approved myeloma database. Responses were evaluated per IMWG Uniform Response Criteria. Results: The median age of this cohort was 61 (range 16-83). Other notable patient characteristics include: M/F 54.6%/45.4%, W/AA 61.8%/35.9%; ISS I/II/III 45.8%/30.8%/23.4%. R-ISS I/II/III 39.9%/48.7%/11.5%; Isotype IgG/IgA/FLC 59.2%/19.0%/15.7%; standard risk(SR)/high risk (HR) 71.2%/15.8%.. High risk disease was defined as the presence of t(4;14), t(14;16), del(17p), and/or complex karyotype by conventional metaphase cytogenetics. 81.8% of patients underwent ASCT, with 16.8% having deferred ASCT. 75.3% of patients were initiated on maintenance therapy. With a median follow up of 88.4 months, the median PFS for the entire cohort was 68.7 months (95% CI 61.8-75.5) and the median OS was 128.9 months. The median PFS for HR patients was 42.4 months (95% CI 35.7-48.9), and the median PFS for SR patients was 80.3 months (95% CI 72.8-87.8). The median OS for SR patients was not reached, and for HR patients was 86.6 months (95% CI 70.1-103.1). Conclusions: Updated analysis with long-term follow up of this database of 1000 NDMM patients treated with RVD continues to demonstrate that, in combination with a risk-stratified maintenance strategy, RVD delivers durable remissions and impressive long-term outcomes. This study remains the largest cohort of patients treated with RVD reported to date, and continues to show the efficacy of this upfront treatment approach in newly diagnosed myeloma.

Prognostic impact of t(11;14) on PFS1 among patients with myeloma receiving triplet induction therapy

8064

Background: Presence of t(11;14) on plasma cells by FISH or metaphase cytogenetics is considered a standard-risk prognostic factor per IMWG risk-stratification. However, recent studies suggest inferior PFS and OS observed among t(11;14) patients relative to the standard-risk myeloma patients. In the context of the ongoing trials of BCL-2 inhibitors (venetoclax) among t(11;14) relapse/refractory myeloma patients yielding response rates closer to 90%, we review the prognostic impact of t(11;14) on PFS. These results may have implications for earlier incorporation of BCL-2 inhibitors among t(11;14) myeloma patients. Methods: Among the 1000 consecutive newly diagnosed myeloma patients uniformly treated with RVD induction therapy from January 2008 until August 2016, we have information on FISH probes for t(11;14) tested for 869 patients [121 - t(11;14) and 748 – no t(11;14)]. First, we explore the frequency of IMWG defined concomitant high-risk cytogenetic characteristics [del 17p, t(4;14), t (14;16)]. Next, we create a synthetic control cohort that received maintenance, and excluded patients exhibiting high-risk features to evaluate the relative prognostication conferred by presence of t(11;14). Median follow up was 91 months. Demographic and outcomes data were collected from IRB approved myeloma database and responses were evaluated per IMWG Uniform Response Criteria. Results: Median age is 61.2 years (range 16.3-79.83). 34% of the patients are above the age of 65. Men (14.1% vs 11.7%, p = NS) and blacks had higher rates of t(11;14) (16.1% vs 11.1%, p = 0.028). 17 (14%) had concomitant high-risk features – 4 (3.3%) had t(4;14), 3 (2.5%) had t(14;16) and 11 (9.1%) had del17p. Interestingly, the rates of amplification of 1q (26.1% vs 14.9%, p = 0.002), and del13 (34.7% vs 24.4%, p = 0.015) were higher among t(11;14) patients. Compared to the synthetic cohort, the post-induction and post-transplant responses were lower for t(11;14) patients as summarized in table 1. ≥VGPR for t(11;14) vs no t(11;14) post-induction were 48.2% vs 71.5% p < 0.001 and post-transplant were 83.1% vs 92.8% p = 0.001, respectively. The median progression-free survival for the t(11;14) and non-t(11;14) groups were 61.4 months (95% confidence interval (CI), 49.13-73.67) and 82.56 months (95% CI, 70.47-94.65) months, respectively (p = 0.002). Conclusions: Even with the use of modern day induction regimens and transplant, patients with t(11;14) seem to have inferior response rates compared to the other standard-risk myelomas. The lower rates of ≥VGPR post-induction and the shorter median PFS suggests BCL-2 inhibitors such as venetoclax may be incorporated earlier in myeloma treatments to improve the outcomes of t(11;14) patients on par with the other standard-risk myeloma patients.

Randomized phase II trial of bortezomib, lenalidomide, dexamthasone with/without elotuzumab for newly diagnosed, high risk multiple myeloma (SWOG-1211)

8054

Background: The introduction of immunomodulatory agents, proteasome inhibitors, and autologous stem cell transplantation (ASCT) has improved outcomes for patients with multiple myeloma (MM), but those with high risk MM (HRMM) have a poor long-term prognosis. Herein we provide survival outcomes on the first randomized trial in newly diagnosed HRMM, S1211, to follow-up on the previously reported progression-free survival (PFS) (NCT01668719, Usmani SZ et al, Lancet Haem 2021). Methods: S1211 is a randomized phase II trial comparing 8 cycles of lenalidomide, bortezomib and dexamethasone (RVd) induction followed by dose-attenuated RVd maintenance until disease progression with or without elotuzumab (RVd-Elo). Stem cell collection was allowed, but ASCT was deferred until progression. HRMM was defined by one of the following: gene expression profiling high-risk (GEPhi), t(14;16), t(14;20), del(17p), amplification 1q21, primary plasma cell leukemia (pPCL), or elevated serum LDH (> 2X ULN). Median PFS was the primary endpoint, using a one-sided stratified log-rank test at a one-sided significance level of 0.1. Secondary endpoints included overall response rate (ORR), adverse events (AE), serious adverse events (SAE) and OS. Response was assessed using the IMWG 2009 criteria. Results: S1211 enrolled 103 evaluable patients, RVd n=54, RVd-Elo n=49. 74% had ISS II/III, 48% amp1q21, 38% del(17p), 11% t(14;16), 9% GEPhi, 7% pPCL, 5% t(14;20) and 4% elevated LDH (17% >1 feature). With median follow-up of 72 months (mos.), no difference in median PFS was observed [RVd-Elo=29 mos., RVd= 34 mos., HR = 1.11 (80% CI=0.82, 1.49, p=0.66]. No difference in OS was observed [RVd-Elo = median not reached (NR), RVd= 68 mos., HR = 0.85 (80% CI: 0.59, 1.23), p-value = 0.58]. 76% pts had >Grade 3 AEs, no differences in the safety profile were observed. Amongst patients with gain/amp 1q21, median PFS was [RVd-Elo=31 mos., RVd= 37 mos., HR = 1.48 (80% CI= 0.95, 2.31), p=0.25], median OS was [RVd-Elo = 61 mos., RVd= 68 mos., HR = 1.23 (80% CI: 0.72, 2.10), p-value = 0.63]. In patients with del(17p), median PFS was RVd-Elo=41 mos., RVd= 30 mos.[HR = 0.98 (80% CI= 0.60, 1.58), p=0.95], median OS RVd-Elo = NR, RVd= 72 mos., [HR = 0.77 (80% CI: 0.40, 1.48), p-value = 0.61]. Conclusions: In the first randomized HRMM study reported to date, the addition of Elo to RVd induction and maintenance did not improve PFS and OS with a median follow-up of 6 years. Although the median PFS for Del17p subgroup on RVd-Elo arm is higher than RVd, it did not achieve statistical significance. The PFS and OS observed for gain/amp 1q21 and del17p in the RVd control arm may serve as important benchmarks for future enrichment design HRMM clinical trials. The PFS and OS in both arms of the study exceeded the original statistical assumptions and support the role for PI/IMiD combination induction/maintenance therapy for this population. Clinical trial information: NCT01668719.

The impact of complex karyotype identified by conventional cytogenetics on survival outcomes of 1,000 patients with newly diagnosed myeloma (NDMM)

8063

Background: Complex karyotype (CK), defined as two or more cytogenetic abnormalities on conventional metaphase cytogenetics, is not routinely used for the risk-stratification or treatment determination in patients with newly diagnosed myeloma (NDMM). Here, we present a retrospective analysis utilizing our institutional data of NDMM patients treated with RVD and a risk-adapted maintenance strategy at the Winship Cancer Institute of Emory University to assess the impact of CK on long-term outcomes. Methods:1000 consecutive NDMM patients treated with RVD induction therapy (R25mg/day, days 1-14; V1.3 mg/m2, days 1,4,8,11 and D40mg once/twice weekly as tolerated) were identified from January 2007 to August 2016. Demographics, clinical characteristics and outcome data for patients were obtained from our institutional review board-approved myeloma database. Responses were evaluated per IMWG Uniform Response Criteria. Results: The median age of this cohort was 61 (range 16-83). Notable patient characteristics include: M/F 54.6%/45.4%, W/AA 61.8%/35.9%; ISS I/II/III 45.8%/30.8%/23.4%. R-ISS I/II/III 39.9%/48.7%/11.5%; Isotype IgG/IgA/FLC 59.2%/19.0%/15.7%; standard risk(SR)/high risk(HR) 71.2%/15.8%. ISS data was available for 75% of patients; R-ISS was available for 41% of patients. HR disease defined as the presence of t(4;14), t(14;16), del(17p) and/or CK. Frequency of specific CTG abnormalities were:14.9% with +1q21, 8.3% with del(1p),12.1% with t(11;14), 25.7% with del(13), 13.9% with CK, 2.8% with t(14;16), 10% with del(17p), and 4.8% with t(4;14). 11.9% of patients were classified high risk by FISH alone, 10.0% of patients were classified as high risk by complex karyotype(CK), and 3.9% of patients were classified as high risk by the presence of both high-risk FISH and CK. With a median follow up of 88.4 months, the median PFS (mPFS) for patients HR by FISH alone was 47.6 months (95% CI 35.2-59.9), for HR by CK alone was 46.9 months (95% CI 28.1-65.7) and for HR by both was 24.0 months (95% CI 8.3-39.7). The mOS for HR by FISH alone was 94.7 months (95% CI 74.4-115.1),HR by CK alone was 105.9 months (95% CI 60.8-151.0) and HR by both was 41.0 months (95% CI 24.2-57.8). Conclusions: CK by conventional metaphase cytogenetics is not currently included in the risk-stratification or risk stratification models of NDMM patients. In patients with a complex karyotype at time of diagnosis, mPFS and mOS is essentially the same as patients classified HR by FISH abnormalities. When compared to SR patients, prognosis is significantly worse, therefore the standard treatment approach is likely insufficient. As many centers do not routinely perform chromosome analysis, this highlights a gap in providing appropriate risk-stratified care. Moreover, NDMM with HR features by FISH and CK portends a poor prognosis for which alternative treatment strategies may need to be explored.

Analysis of long-term outcomes in R-ISS stage 2 multiple myeloma with and without the presence of high-risk cytogenetics

8059

Background: The Revised International Staging System (R-ISS) is the current standard for risk-stratification of newly diagnosed myeloma (NDMM), incorporating albumin and β2M with high-risk cytogenetics and/or elevated LDH. (Palumbo et al, JCO 2015) R-ISS stage 2 represents a heterogeneous cohort including myeloma with and without high-risk cytogenetics, a known poor prognosticator. Here, we present a retrospective analysis on outcomes of R-ISS stage 2 NDMM utilizing our institutional database of patients treated at the Winship Cancer Institute of Emory University. Methods: From January 2007 to August 2016, 1,000 consecutive newly diagnosed myeloma patients treated with RVD induction therapy were identified. Demographics, clinical characteristics, and outcomes data for the patients were obtained from our institutional review board-approved myeloma database. Responses were evaluated per IMWG Uniform Response Criteria. Results: The median age of this cohort was 61 years (range 16-83). Other notable patient characteristics include: M/F 54.6%/45.4%, W/AA 61.8%/35.9%; ISS I/II/III 45.8%/30.8%/23.4%. R-ISS I/II/III 39.9%/48.7%/11.5%; Isotype IgG/IgA/FLC 59.2%/19.0%/15.7%; standard risk (SR)/high risk (HR) 71.2%/15.8%. ISS data was available for 75% of patients; R-ISS was available for 41% of patients. HR disease was defined as the presence of t(4;14), t(14;16), del(17p), and/or complex karyotype by conventional metaphase cytogenetics. Frequency of specific CTG abnormalities were 2.8% with t(14;16), 10% with del(17p), and 4.8% with t(4;14). With a median follow up of 88.4 months, the median PFS (mPFS) for the entire cohort was 68.7 months (95% CI 61.8-75.5) and the median OS was 128.9 months. The median PFS for HR vs SR patients was 42.4 months (95% CI 35.7-48.9) vs 80.3 months (95% CI 72.8-87.8). The median OS for SR patients was not reached, and for HR patients was 86.6 months (95% CI 70.1-103.1). The mPFS for R-ISS 1,2 and 3 was 95.4 months (95% CI 73.4-117.5), 56.6 months (95% CI 44.4-68.7), and 31.1 months (95% CI 16.3-45.9). When the R-ISS 2 cohort was divided into those without HR CTG and with HR CTG, the mPFS was 67.1 months (95% CI 53.3-80.8) versus 40.2 months (95% CI 30.1-50.3), respectively. The mOS for R-ISS I/II/III was NR, 122.7 months (95% CI 101.6-143.9), and 60.6 months (95% CI 11.6-109.5). For R-ISS 2 without and with HR CTG, the mOS was 129.1 months and 94.8 months (95% CI 61.3-128.3), respectively. Conclusions: The R-ISS is a validated risk model clearly defining three distinct groups in terms of long-term outcomes. However, these data suggest R-ISS stage 2 can further be characterized into two distinct groups based on the presence or absence of high risk cytogenetics. R-ISS 2 with HR-CTG portends both inferior mPFS and increased risk of death when compared to R-ISS 2 without HR-CTG (HR 2.63 versus HR 1.65), and behaves more similarly to R-ISS 3 disease.

Determinants of Neutralizing Antibody Response After SARS CoV-2 Vaccination in Patients With Myeloma

PURPOSE

Vaccine-induced neutralizing antibodies (nAbs) play a critical role in protection from SARS CoV-2. Patients with B-cell malignancies including myeloma are at increased risk of COVID-19-related mortality and exhibit variable serologic response to the vaccine. The capacity of vaccine-induced antibodies in these patients to neutralize SARS CoV-2 or its variants is not known.

METHODS

Sera from 238 patients with multiple myeloma (MM) undergoing SARS CoV-2 vaccination were analyzed. Antibodies against the SARS CoV-2 spike receptor-binding domain (RBD) and viral nucleocapsid were measured to detect serologic response to vaccine and environmental exposure to the virus. The capacity of antibodies to neutralize virus was quantified using pseudovirus neutralization assay and live virus neutralization against the initial SARS CoV-2 strain and the B1.617.2 (Delta) variant.

RESULTS

Vaccine-induced nAbs are detectable at much lower rates (54%) than estimated in previous seroconversion studies in MM, which did not monitor viral neutralization. In 33% of patients, vaccine-induced antispike RBD antibodies lack detectable neutralizing capacity, including against the B1.617.2 variant. Induction of nAbs is affected by race, disease, and treatment-related factors. Patients receiving mRNA1273 vaccine (Moderna) achieved significantly greater induction of nAbs compared with those receiving BNT162b2 (Pfizer; 67% v 48%, P = .006).

CONCLUSION

These data show that vaccine-induced antibodies in several patients with MM lack detectable virus-neutralizing activity. Vaccine-mediated induction of nAbs is affected by race, disease, vaccine, and treatment characteristics. These data have several implications for the emerging application of booster vaccines in immunocompromised hosts.

Rapid, high throughput, automated detection of SARS-CoV-2 neutralizing antibodies against native-like vaccine and delta variant spike trimers

Traditional cellular and live-virus methods for detection of SARS-CoV-2 neutralizing antibodies (nAbs) are labor- and time-intensive, and thus not suited for routine use in the clinical lab to predict vaccine efficacy and natural immune protection. Here, we report the development and validation of a rapid, high throughput method for measuring SARS-CoV-2 nAbs against native-like trimeric spike proteins. This assay uses a blockade of hACE-2 binding (BoAb) approach in an automated digital immunoassay on the Quanterix HD-X platform. BoAb assays using vaccine and delta variant viral strains showed strong correlation with cell-based pseudovirus and live-virus neutralization activity. Importantly, we were able to detect similar patterns of delta variant resistance to neutralization in samples with paired vaccine and delta variant BoAb measurements. Finally, we screened clinical samples from patients with or without evidence of SARS-CoV-2 exposure by a single-dilution screening version of our assays, finding significant nAb activity only in exposed individuals. In principle, these assays offer a rapid, robust, and scalable alternative to time-, skill-, and cost-intensive standard methods for measuring SARS-CoV-2 nAb levels.

Rapid, high throughput, automated detection of SARS-CoV-2 neutralizing antibodies against native-like vaccine and delta variant spike trimers

Traditional cellular and live-virus methods for detection of SARS-CoV-2 neutralizing antibodies (nAbs) are labor- and time-intensive, and thus not suited for routine use in the clinical lab to predict vaccine efficacy and natural immune protection. Here, we report the development and validation of a rapid, high throughput method for measuring SARS-CoV-2 nAbs against native-like trimeric spike proteins. This assay uses a blockade of hACE-2 binding (BoAb) approach in an automated digital immunoassay on the Quanterix HD-X platform. BoAb assays using vaccine and delta variant viral strains showed strong correlation with cell-based pseudovirus and live-virus neutralization activity. Importantly, we were able to detect similar patterns of delta variant resistance to neutralization in samples with paired vaccine and delta variant BoAb measurements. Finally, we screened clinical samples from patients with or without evidence of SARS-CoV-2 exposure by a single-dilution screening version of our assays, finding significant nAb activity only in exposed individuals. In principle, these assays offer a rapid, robust, and scalable alternative to time-, skill-, and cost-intensive standard methods for measuring SARS-CoV-2 nAb levels.

How to Provide the Needed Protection from COVID-19 to Patients with Hematologic Malignancies

Patients with hematologic malignancies are particularly vulnerable to COVID-19 infections, and upon a pooled data analysis of 24 publications, there is evidence that they have suboptimal antibody responses to COVID-19 vaccination and boosters. To provide them the needed additional protection from COVID-19, it is imperative to achieve a 100% full immunization rate in health care workers and adult caretakers, and to foster research to test higher doses and repeated rounds of COVID-19 vaccines and the use of passive immune prophylaxis and therapy.

Aberrant Extrafollicular B Cells, Immune Dysfunction, Myeloid Inflammation, and MyD88-Mutant Progenitors Precede Waldenstrom Macroglobulinemia

Waldenstrom macroglobulinemia (WM) and its precursor IgM gammopathy are distinct disorders characterized by clonal mature IgM-expressing B-cell outgrowth in the bone marrow. Here, we show by high-dimensional single-cell immunogenomic profiling of patient samples that these disorders originate in the setting of global B-cell compartment alterations, characterized by expansion of genomically aberrant extrafollicular B cells of the nonmalignant clonotype. Alterations in the immune microenvironment preceding malignant clonal expansion include myeloid inflammation and naïve B- and T-cell depletion. Host response to these early lesions involves clone-specific T-cell immunity that may include MYD88 mutation-specific responses. Hematopoietic progenitors carry the oncogenic MYD88 mutations characteristic of the malignant WM clone. These data support a model for WM pathogenesis wherein oncogenic alterations and signaling in progenitors, myeloid inflammation, and global alterations in extrafollicular B cells create the milieu promoting extranodal pattern of growth in differentiated malignant cells.

SIGNIFICANCE

These data provide evidence that growth of the malignant clone in WM is preceded by expansion of extrafollicular B cells, myeloid inflammation, and immune dysfunction in the preneoplastic phase. These changes may be related in part to MYD88 oncogenic signaling in pre-B progenitor cells and suggest a novel model for WM pathogenesis. This article is highlighted in the In This Issue feature, p. 549.

Venetoclax sensitivity in multiple myeloma is associated with B-cell gene expression

Venetoclax is a highly potent, selective BCL2 inhibitor capable of inducing apoptosis in cells dependent on BCL2 for survival. Most myeloma is MCL1-dependent; however, a subset of myeloma enriched for translocation t(11;14) is codependent on BCL2 and thus sensitive to venetoclax. The biology underlying this heterogeneity remains poorly understood. We show that knockdown of cyclin D1 does not induce resistance to venetoclax, arguing against a direct role for cyclin D1 in venetoclax sensitivity. To identify other factors contributing to venetoclax response, we studied a panel of 31 myeloma cell lines and 25 patient samples tested for venetoclax sensitivity. In cell lines, we corroborated our previous observation that BIM binding to BCL2 correlates with venetoclax response and further showed that knockout of BIM results in decreased venetoclax sensitivity. RNA-sequencing analysis identified expression of B-cell genes as enriched in venetoclax-sensitive myeloma, although no single gene consistently delineated sensitive and resistant cells. However, a panel of cell surface makers correlated well with ex vivo prediction of venetoclax response in 21 patient samples and may serve as a biomarker independent of t(11;14). Assay for transposase-accessible chromatin sequencing of myeloma cell lines also identified an epigenetic program in venetoclax-sensitive cells that was more similar to B cells than that of venetoclax-resistant cells, as well as enrichment for basic leucine zipper domain-binding motifs such as BATF. Together, these data indicate that remnants of B-cell biology are associated with BCL2 dependency and point to novel biomarkers of venetoclax-sensitive myeloma independent of t(11;14).

Tandem high-dose influenza vaccination is associated with more durable serologic immunity in patients with plasma cell dyscrasias

Patients with plasma cell dyscrasias (PCDs) experience an increased burden of influenza, and current practice of single-dose annual influenza vaccination yields suboptimal protective immunity in these patients. Strategies to improve immunity to influenza in these patients are clearly needed. We performed a randomized, double-blind, placebo-controlled clinical trial comparing tandem Fluzone High-Dose influenza vaccination with standard-of-care influenza vaccination. Standard-of-care vaccination was single-dose age-based vaccination (standard dose, <65 years; high dose, ≥65 years), and patients in this arm received a saline placebo injection at 30 days. A total of 122 PCD patients were enrolled; 47 received single-dose standard-of-care vaccination, and 75 received 2 doses of Fluzone High-Dose vaccine. Rates of hemagglutinin inhibition (HAI) titer seroprotection against all 3 strains (H1N1, H3N2, and influenza B) were significantly higher for patients after tandem high-dose vaccination vs control (87.3% vs 63.2%; P = .003) and led to higher seroprotection at the end of flu season (60.0% vs 31.6%; P = .04). These data demonstrate that tandem high-dose influenza vaccination separated by 30 days leads to higher serologic HAI titer responses and more durable influenza-specific immunity in PCD patients. Similar vaccine strategies may also be essential to achieve protective immunity against other emerging pathogens such as novel coronavirus in these patients. This trial was registered at www.clinicaltrials.gov as #NCT02566265.

Co-evolution of Immune Response in Multiple Myeloma: Implications for Immune Prevention

Multiple myeloma (MM), a malignant neoplasm of plasma cells that reside in the bone marrow (BM), is universally preceded by a precursor state termed monoclonal gammopathy of undetermined significance (MGUS). Many individuals with MGUS never progress to MM or progress over many years. Therefore, MGUS provides a unique opportunity to surveil changes in the BM tumor microenvironment throughout disease progression. It is increasingly appreciated that MGUS cells carry many of the genetic changes found in MM. Prior studies have also shown that MGUS cells can be recognized by the immune system, leading to early changes in the BM immune environment compared to that of healthy individuals, including alterations in both innate and adaptive immunity. Progression to clinical MM is associated with attrition of T cells with stem memory-like features and instead accumulation of T cells with more terminally differentiated features. Recent clinical studies have suggested that early application of immune-modulatory drugs, which are known to activate both innate and adaptive immunity, can delay the progression to clinical MM. Understanding the biology of how the immune response and tumors coevolve over time is needed to develop novel immune-based approaches to achieve durable and effective prevention of clinical malignancy.

Game of Bones: How Myeloma Manipulates Its Microenvironment

Multiple myeloma is a clonal disease of long-lived plasma cells and is the second most common hematological cancer behind Non-Hodgkin’s Lymphoma. Malignant transformation of plasma cells imparts the ability to proliferate, causing harmful lesions in patients. In advanced stages myeloma cells become independent of their bone marrow microenvironment and form extramedullary disease. Plasma cells depend on a rich array of signals from neighboring cells within the bone marrow for survival which myeloma cells exploit for growth and proliferation. Recent evidence suggests, however, that both the myeloma cells and the microenvironment have undergone alterations as early as during precursor stages of the disease. There are no current therapies routinely used for treating myeloma in early stages, and while recent therapeutic efforts have improved patients’ median survival, most will eventually relapse. This is due to mutations in myeloma cells that not only allow them to utilize its bone marrow niche but also facilitate autocrine pro-survival signaling loops for further progression. This review will discuss the stages of myeloma cell progression and how myeloma cells progress within and outside of the bone marrow microenvironment.

Viral Immunity and Vaccines in Hematologic Malignancies: Implications for COVID-19

Patients with hematologic malignancies have increased susceptibility to viral infections and suboptimal immunologic responses to current vaccines due to both disease-associated and therapy-related immune dysfunction. These considerations may impact the efficacy of emerging COVID-19 vaccines in this patient population as well and warrant the need to systematically study natural and vaccine-induced virus-specific immunity in these patients.

Bone marrow microenvironments that contribute to patient outcomes in newly diagnosed multiple myeloma: A cohort study of patients in the Total Therapy clinical trials

BACKGROUND

The tumor microenvironment (TME) is increasingly appreciated as an important determinant of cancer outcome, including in multiple myeloma (MM). However, most myeloma microenvironment studies have been based on bone marrow (BM) aspirates, which often do not fully reflect the cellular content of BM tissue itself. To address this limitation in myeloma research, we systematically characterized the whole bone marrow (WBM) microenvironment during premalignant, baseline, on treatment, and post-treatment phases.

METHODS AND FINDINGS

Between 2004 and 2019, 998 BM samples were taken from 436 patients with newly diagnosed MM (NDMM) at the University of Arkansas for Medical Sciences in Little Rock, Arkansas, United States of America. These patients were 61% male and 39% female, 89% White, 8% Black, and 3% other/refused, with a mean age of 58 years. Using WBM and matched cluster of differentiation (CD)138-selected tumor gene expression to control for tumor burden, we identified a subgroup of patients with an adverse TME associated with 17 fewer months of progression-free survival (PFS) (95% confidence interval [CI] 5-29, 49-69 versus 70-82 months, χ2 p = 0.001) and 15 fewer months of overall survival (OS; 95% CI -1 to 31, 92-120 versus 113-129 months, χ2 p = 0.036). Using immunohistochemistry-validated computational tools that identify distinct cell types from bulk gene expression, we showed that the adverse outcome was correlated with elevated CD8+ T cell and reduced granulocytic cell proportions. This microenvironment develops during the progression of premalignant to malignant disease and becomes less prevalent after therapy, in which it is associated with improved outcomes. In patients with quantified International Staging System (ISS) stage and 70-gene Prognostic Risk Score (GEP-70) scores, taking the microenvironment into consideration would have identified an additional 40 out of 290 patients (14%, premutation p = 0.001) with significantly worse outcomes (PFS, 95% CI 6-36, 49-73 versus 74-90 months) who were not identified by existing clinical (ISS stage III) and tumor (GEP-70) criteria as high risk. The main limitations of this study are that it relies on computationally identified cell types and that patients were treated with thalidomide rather than current therapies.

CONCLUSIONS

In this study, we observe that granulocyte signatures in the MM TME contribute to a more accurate prognosis. This implies that future researchers and clinicians treating patients should quantify TME components, in particular monocytes and granulocytes, which are often ignored in microenvironment studies.

Summary of the 2019 Blood and Marrow Transplant Clinical Trials Network Myeloma Intergroup Workshop on Minimal Residual Disease and Immune Profiling

The Blood and Marrow Transplant Clinical Trials Network (BMT CTN) Myeloma Intergroup has organized an annual workshop focused on minimal residual disease (MRD) testing and immune profiling (IP) in multiple myeloma since 2016. In 2019, the workshop took place as an American Society of Hematology (ASH) Friday Scientific Workshop titled "Immune Profiling and Minimal Residual Disease Testing in Multiple Myeloma." This workshop focused on 4 main topics: the molecular and immunologic evolution of plasma cell disorders, development of new laboratory- and imaging-based MRD assessment approaches, chimeric antigen receptor T cell therapy research, and statistical and regulatory issues associated with novel clinical endpoints. In this report, we provide a summary of the workshop and discuss future directions.

Tissue-resident memory-like T cells in tumor immunity: Clinical implications

Tissue-resident memory (T_RM) T cells are distinct population of non-circulating lymphocytes that play an important role in mediating regional immunity. T_RM- like cells have now been identified as a component of tumor-infiltrating lymphocytes in several human tumors and correlate with outcome and response to immunotherapy. T_RM cells have also been shown to mediate anti-tumor immunity in murine models. Biology of T_RM cells has several implications for clinical cancer immunotherapy. Here we discuss newer insights into the biology of T_RM T cells and discuss their implications for understanding the heterogeneity of immune microenvironment in tumors as well as improving the efficacy of cancer vaccines, immune-checkpoint blockade and adoptive cellular therapies in the clinic.

Risk-associated alterations in marrow T cells in pediatric leukemia

Current management of childhood leukemia is tailored based on disease risk determined by clinical features at presentation. Whether properties of the host immune response impact disease risk and outcome is not known. Here, we combine mass cytometry, single cell genomics, and functional studies to characterize the BM immune environment in children with B cell acute lymphoblastic leukemia and acute myelogenous leukemia at presentation. T cells in leukemia marrow demonstrate evidence of chronic immune activation and exhaustion/dysfunction, with attrition of naive T cells and TCF1⁺ stem-like memory T cells and accumulation of terminally differentiated effector T cells. Marrow-infiltrating NK cells also exhibit evidence of dysfunction, particularly in myeloid leukemia. Properties of immune cells identified distinct immune phenotype–based clusters correlating with disease risk in acute lymphoblastic leukemia. High-risk immune signatures were associated with expression of stem-like genes on tumor cells. These data provide a comprehensive assessment of the immune landscape of childhood leukemias and identify targets potentially amenable to therapeutic intervention. These studies also suggest that properties of the host response with depletion of naive T cells and accumulation of terminal-effector T cells may contribute to the biologic basis of disease risk. Properties of immune microenvironment identified here may also impact optimal application of immune therapies, including T cell–redirection approaches in childhood leukemia.

In high risk pediatric leukemia, naive and stem-like memory T cells are depleted and terminally differentiated effector T cells accumulate.