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

Follow-up of humoral and cellular immune responses after the third SARS-CoV-2 vaccine dose in multiple myeloma patients

The stability of immune responses to SARS-CoV-2 vaccines, especially concerning the cross-reactive recognition of the Omicron variant, remains incompletely characterized in multiple myeloma (MM) patients. This study evaluated humoral responses in 29 MM patients and cellular responses in a subset of 19 MM patients, specific to Wuhan and Omicron spike proteins, between 16 and 26 weeks following the third vaccine dose. After 26 weeks, we highlighted a significant reduction in the neutralizing antibodies to both spikes and the percentages of IFN-γ+CD107a+ spike-specific CD8+ T cells. On the other hand, patients who underwent an additional stimulation between the two time points, through either a fourth vaccine dose or breakthrough infection, showed a significant increase in neutralizing antibodies and stable levels of cytotoxic CD8+ T cells. Additionally, those with only three doses experienced a higher rate of breakthrough infections during the 32-week follow-up period. These findings underscore the waning of vaccine-induced immunity over time and may help benefit-risk evaluation in vaccination strategies in MM patients.

The characterization of CD8+ T-cell responses in COVID-19

This review gives an overview of the protective role of CD8+ T cells in SARS-CoV-2 infection. The cross-reactive responses intermediated by CD8+ T cells in unexposed cohorts are described. Additionally, the relevance of resident CD8+ T cells in the upper and lower airway during infection and CD8+ T-cell responses following vaccination are discussed, including recent worrisome breakthrough infections and variants of concerns (VOCs). Lastly, we explain the correlation between CD8+ T cells and COVID-19 severity. This review aids in a deeper comprehension of the association between CD8+ T cells and SARS-CoV-2 and broadens a vision for future exploration.

COVID-19 Vaccination Recommendations for Immunocompromised Patient Populations: Delphi Panel and Consensus Statement Generation in the United States

INTRODUCTION

The United States Advisory Committee on Immunization Practices (ACIP) and the Centers for Disease Control (CDC) recommend COVID-19 vaccines for all immunocompromised individuals. Certain disease groups are at increased risk of comorbidity and death for which disease-specific recommendations should be considered. The objective of the Delphi panel of experts was to summarize expert consensus on COVID-19 vaccinations for patients with rheumatologic disease, renal disease, hematologic malignancy and solid organ transplant (SOT) in the US.

METHODS

A two-stage Delphi panel method was employed, starting with qualitative interviews with key opinion leaders (KOLs) in the four disease areas (n = 4 KOLs, n = 16 total) followed by three rounds of iterative revision of disease-specific COVID-19 vaccine recommendations. Final consensus was rated after the third round. Statements addressed primary and booster dosing (e.g., number and frequency) and other considerations such as vaccine type or heterologous messenger ribonucleic acid (mRNA) vaccination. Following the Delphi Panel, an online survey was conducted to assess physician agreement within the disease areas (n = 50 each, n = 200 total) with the consensus statements.

RESULTS

Moderate to strong consensus was achieved for all primary series vaccination statements across disease groups, except one in hematology. Similarly, moderate to strong consensus was achieved for all booster series statements in all disease areas. However, statements on antibody titer measurements for re-vaccination considerations and higher dosages for immunocompromised patients did not reach agreement. Overall, approximately 62%-96% of physicians strongly agreed with the primary and booster vaccine recommendations. However, low agreement (29%-69%) was found among physicians for time interval between disease-specific treatment and vaccination, recommendations for mRNA vaccines, heterologous mRNA vaccination, antibody titer measurement and higher vaccine dosage for immunocompromised groups.

CONCLUSION

Consensus was achieved for disease-specific COVID-19 vaccine recommendations concerning primary and booster series vaccines and was generally well accepted by practicing physicians.

Divergence of variant antibodies following SARS-CoV-2 booster vaccines in myeloma and impact of hybrid immunity

Hematological malignancies are associated with an increased risk of complications during SARS-CoV-2 infections. Primary series or monovalent booster vaccines reduce disease severity, hospitalization, and death among multiple myeloma patients. We characterized virus-neutralizing and spike-binding antibody profiles following monovalent (WA1) or bivalent (WA1/BA.5) SARS-CoV-2 booster vaccination in MM patients. Bivalent vaccination improved the breadth of binding antibodies but not neutralization activity against contemporary variants. Hybrid immunity and immune imprinting impact vaccine-elicited immunity.

Immune dysfunction prior to and during vaccination in multiple myeloma: a case study based on COVID-19

Infection is the leading cause of death in multiple myeloma (MM). However, the cellular composition associated with immune dysfunction is not defined. We analyzed immune profiles in the peripheral blood of patients with MM (n = 28) and B-cell chronic lymphoproliferative disorders (n = 53) vs. health care practitioners (n = 96), using multidimensional and computational flow cytometry. MM patients displayed altered distribution of most cell types (41/56, 73%), particularly within the B-cell (17/17) and T-cell (20/30) compartments. Using COVID-19 as a case study, we compared the immune response to vaccination based on 64,304 data points generated from the analysis of 1099 longitudinal samples. MM patients showed limited B-cell expansion linked to lower anti-RBD and anti-S antibody titers after the first two doses and booster. The percentages of B cells and CD4+ T cells in the blood, as well as the absolute counts of B cells and dendritic cells, predicted vaccine immunogenicity at different time points. In contrast with the humoral response, the percentage and antigen-dependent differentiation of SARS-CoV-2-specific CD8+ T cells was not altered in MM patients. Taken together, this study defined the cellular composition associated with immune dysfunction in MM and provided biomarkers such as the B-cell percentage and absolute count to individualize vaccination calendars.

Next-Generation Therapies for Multiple Myeloma

Recent therapeutic advances have significantly improved the outcome for patients with multiple myeloma (MM). The backbone of successful standard therapy is the combination of Ikaros degraders, glucocorticoids, and proteasome inhibitors that interfere with the integrity of myeloma-specific superenhancers by directly or indirectly targeting enhancer-bound transcription factors and coactivators that control expression of MM dependency genes. T cell engagers and chimeric antigen receptor T cells redirect patients' own T cells onto defined tumor antigens to kill MM cells. They have induced complete remissions even in end-stage patients. Unfortunately, responses to both conventional therapy and immunotherapy are not durable, and tumor heterogeneity, antigen loss, and lack of T cell fitness lead to therapy resistance and relapse. Novel approaches are under development to target myeloma-specific vulnerabilities, as is the design of multimodality immunological approaches, including and beyond T cells, that simultaneously recognize multiple epitopes to prevent antigen escape and tumor relapse.

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

ABSTRACT

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

Breakthrough Infections in SARS-CoV-2-Vaccinated Multiple Myeloma Patients Improve Cross-Protection against Omicron Variants

Patients with multiple myeloma (MM) are a heterogenous, immunocompromised group with increased risk for COVID-19 morbidity and mortality but impaired responses to primary mRNA SARS-CoV-2 vaccination. The effects of booster vaccinations and breakthrough infections (BTIs) on antibody (Ab) levels and cross-protection to variants of concern (VOCs) are, however, not sufficiently evaluated. Therefore, we analysed humoral and cellular vaccine responses in MM patients stratified according to disease stage/treatment into group (1) monoclonal gammopathy of undetermined significance, (2) after stem cell transplant (SCT) without immunotherapy (IT), (3) after SCT with IT, and (4) progressed MM, and in healthy subjects (prospective cohort study). In contrast to SARS-CoV-2 hu-1-specific Ab levels, Omicron-specific Abs and their cross-neutralisation capacity remained low even after three booster doses in a majority of MM patients. In particular, progressed MM patients receiving anti-CD38 mAb and those after SCT with IT were Ab low responders and showed delayed formation of spike-specific B memory cells. However, MM patients with hybrid immunity (i.e., vaccination and breakthrough infection) had improved cross-neutralisation capacity against VOCs, yet in the absence of severe COVID-19 disease. Our results indicate that MM patients require frequent variant-adapted booster vaccinations and/or changes to other vaccine formulations/platforms, which might have similar immunological effects as BTIs.

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.

The impact of COVID-19 on cancer patients

The COVID-19 pandemic poses a significant challenge for individuals with compromised immune systems, such as patients with cancer, as they face a heightened susceptibility to severe infections compared to the general population. Such severe infections substantially increase the risk of morbidity and mortality among these patients. Notable risk factors for mortality include advanced age (> 70 years), current or past smoking history, advanced disease stage, the use of cytotoxic chemotherapy, and an Eastern Cooperative Oncology Group (ECOG) score of 2 or higher. Multiple types of vaccines have been developed and implemented, demonstrating remarkable efficacy in preventing infections. However, there have been observable reductions in their ability to elicit an immune response, particularly among individuals with hematological malignancies. The situation becomes more challenging due to the emergence of viral variants of concern (VOCs). Despite the increase in neutralizing antibody levels after vaccination, they remain lower in response to these evolving variants. The need for booster vaccinations has become apparent, particularly for this vulnerable population, due to the suboptimal immune response and waning of immunity post-vaccination. Examining and comprehending how the immune system reacts to various vaccination regimens for SARS-CoV-2 and its VOCs in cancer patients is crucial for designing clinical and public health strategies. This review aims to provide an updated overview of the effectiveness of COVID-19 vaccines in cancer patients, including those undergoing treatments such as hematopoietic stem cell transplantation (HCT) or chimeric antigen receptor (CAR) T cell therapy, by exploring the extent of both humoral and cellular immune responses to COVID-19 vaccination. Furthermore, it outlines risk factors and potential biomarkers that are associated with severe SARS-CoV-2 infection and vaccine responses, and offers suggestions for improving SARS-CoV-2 protection in cancer patients.

Teclistamab impairs humoral immunity in patients with heavily pretreated myeloma: importance of immunoglobulin supplementation

ABSTRACT

Teclistamab and other B-cell maturation antigen (BCMA)-targeting bispecific antibodies (BsAbs) have substantial activity in patients with heavily pretreated multiple myeloma (MM) but are associated with a high rate of infections. BCMA is also expressed on normal plasma cells and mature B cells, which are essential for the generation of a humoral immune response. The aim of this study was to improve the understanding of the impact of BCMA-targeting BsAbs on humoral immunity. The impact of teclistamab on polyclonal immunoglobulins and B cell counts was evaluated in patients with MM who received once-weekly teclistamab 1.5 mg/kg subcutaneously. Vaccination responses were assessed in a subset of patients. Teclistamabinduced rapid depletion of peripheral blood B cells in patients with MM and eliminated normal plasma cells in ex vivo assays. In addition, teclistamab reduced the levels of polyclonal immunoglobulins (immunoglobulin G [IgG], IgA, IgE, and IgM), without recovery over time while receiving teclistamab therapy. Furthermore, response to vaccines against Streptococcus pneumoniae, Haemophilus influenzae type B, and severe acute respiratory syndrome coronavirus 2 was severely impaired in patients treated with teclistamab compared with vaccination responses observed in patients with newly diagnosed MM or relapsed/refractory MM. Intravenous immunoglobulin (IVIG) use was associated with a significantly lower risk of serious infections among patients treated with teclistamab (cumulative incidence of infections at 6 months: 5.3% with IVIG vs 54.8% with observation only [P < .001]). In conclusion, our data show severe defects in humoral immunity induced by teclistamab, the impact of which can be mitigated by the use of immunoglobulin supplementation. This trial was registered at www.ClinicalTrials.gov as #NCT04557098.

mRNA vaccines against SARS-CoV-2 induce divergent antigen-specific T-cell responses in patients with lung cancer

BACKGROUND

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant is highly transmissible and evades pre-established immunity. Messenger RNA (mRNA) vaccination against ancestral strain spike protein can induce intact T-cell immunity against the Omicron variant, but efficacy of booster vaccination in patients with late-stage lung cancer on immune-modulating agents including anti-programmed cell death protein 1(PD-1)/programmed death-ligand 1 (PD-L1) has not yet been elucidated.

METHODS

We assessed T-cell responses using a modified activation-induced marker assay, coupled with high-dimension flow cytometry analyses. Peripheral blood mononuclear cells (PBMCs) were stimulated with various viral peptides and antigen-specific T-cell responses were evaluated using flow cytometry.

RESULTS

Booster vaccines induced CD8+ T-cell response against the ancestral SARS-CoV-2 strain and Omicron variant in both non-cancer subjects and patients with lung cancer, but only a marginal induction was detected for CD4+ T cells. Importantly, antigen-specific T cells from patients with lung cancer showed distinct subpopulation dynamics with varying degrees of differentiation compared with non-cancer subjects, with evidence of dysfunction. Notably, female-biased T-cell responses were observed.

CONCLUSION

We conclude that patients with lung cancer on immunotherapy show a substantial qualitative deviation from non-cancer subjects in their T-cell response to mRNA vaccines, highlighting the need for heightened protective measures for patients with cancer to minimize the risk of breakthrough infection with the Omicron and other future variants.

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.

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.

Defective Immunity Against SARS-CoV-2 Omicron Variants Despite Full Vaccination in Hematologic Malignancies

SUMMARY

In patients with multiple myeloma, completion of mRNA-based vaccination schemes failed to yield detectable SARS-CoV-2 Omicron-neutralizing antibodies and S1-RBD-specific CD8+ T cells in approximately 60% and 80% of the cases, respectively. Patients who develop breakthrough infections exhibited very low levels of live-virus neutralizing antibodies and the absence of follicular T helper cells. See related article by Azeem et al., p. 106 (9). See related article by Chang et al., p. 1684 (10).

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.