Viral infection/reactivation during long-term follow-up in multiple myeloma patients with anti-BCMA CAR therapy

When Chinese patients with plasma cell disorders encountered the nationwide Omicron outbreak (December 2022): a real-world multicenter and multiregional study

OBJECTIVES

This study aims to assess the impact of the nationwide Omicron outbreak in December 2022 on Chinese patients with plasma cell disorders (PCD), focusing on the clinical characteristics of PCD patients with COVID-19 and the risk factors contributing to adverse clinical courses (severity and hospitalization) and outcomes.

METHODS

A multicenter retrospective study was performed from December 1, 2022, to January 19, 2023. The study population includes 404 PCD patients, divided into a COVID-19 group (n = 342) and an uninfected group (n = 62).

RESULTS

The frequency of COVID-19 infection was 84.7% (342/404), and 16.4% (56/342) were severe COVID-19. Among the 277 patients with complete follow-up, 2 deaths (0.7%) were reported, while 231 (83.4%) recovered from COVID-19. Age > 65 (P = 0.02) and prior anti-CD38 monoclonal antibody (mAb) treatment within six months (P = 0.03) were independent risk factors for severe infection. Additionally, previous chimeric antigen receptor T-cell (CAR-T) therapy within six months was correlated with a higher risk of hospitalization (P = 0.04) and prolonged recovery time (P = 0.03). No significant protective effect of vaccination on infection or severe infection was observed (P > 0.05).

CONCLUSIONS

The latest Omicron outbreak results in higher rates of severe infection and mortality in PCD patients compared with the general population in China, highlighting the need to protect this vulnerable population during the pandemic. Recent use of anti-CD38 mAb and CAR-T therapy are associated with poorer clinical courses and outcomes of PCD patients with COVID-19.

Chimeric antigen receptor-T-cell therapies going viral: latent and incidental viral infections

PURPOSE OF REVIEW

Infections are the leading cause of non-relapse mortality following chimeric antigen receptor (CAR)-T-cell therapy, with viral infections being frequent both in the early and late phases post-infusion. We review the epidemiology of viral infections and discuss critical approaches to prevention and management strategies in this setting.

RECENT FINDINGS

Herpesviruses dominate the early period. herpes simplex virus and varicella zoster virus infections are rare due to widespread antiviral prophylaxis, but cytomegalovirus (CMV) reactivation is increasingly observed, particularly in high-risk groups including B cell maturation antigen (BCMA)-CAR-T-cell therapy recipients and patients receiving corticosteroids. While CMV end-organ disease is rare, CMV is associated with increased mortality, emphasizing the need to evaluate the broader impact of CMV on long-term hematological, infection, and survival outcomes. Human herpesvirus-6 (HHV-6) has also emerged as a concern, with its diagnosis complicated by overlapping symptoms with neurotoxicity, underscoring the importance of considering viral encephalitis in differential diagnoses. Respiratory viruses are the most common late infections with a higher incidence after BCMA CAR-T-cell therapy. Vaccination remains a critical preventive measure against respiratory viruses but may be less immunogenic following CAR-T-cell therapy. The optimal timing, type of vaccine, and dosing schedule require further investigation.

SUMMARY

A better understanding of viral epidemiology and preventive trials are needed to improve infection prevention practices and outcomes following CAR-T-cell therapies.

Recommendations for the effective use of T-cell-redirecting therapies: a Canadian consensus statement

Background

T-cell-redirecting therapies, such as bispecific antibodies and chimeric antigen receptor T-cells, exploit the cytotoxic capabilities of the immune system to destroy cells expressing specific surface antigens, including malignant cells. These therapies have demonstrated unprecedented rates, depth, and duration of responses in relapsed and refractory multiple myeloma. However, there are significant challenges in implementing these therapies into practice, which require multidisciplinary and multicenter coordination and significant healthcare resources to effectively manage these patients. So far, there are no Canadian guidelines for the effective implementation and use of T-cell-redirecting therapies.

Methods

This consensus statement was developed based on three advisory meetings held in March, July, and November 2023. During these meetings, a panel of Canadian subject matter experts and representation from Myeloma Canada gathered to discuss the optimal procedures for the use of T-cell-redirecting therapies in the treatment of multiple myeloma. Members of the panel performed a thorough review of randomized clinical trials, real-world data, and other current literature, and provided their up-to-date clinical experience with T-cell-redirecting therapies in Canadian practice settings. Subsequently, asynchronous working groups were appointed to develop unified criteria for patient selection, appraise referral pathways, and devise strategies for management of short-term and long-term adverse events arising from the use of T-cell-redirecting therapies in multiple myeloma.

Results

Here, we present recommendations for optimizing patient selection, referral pathways, and adverse event management in the Canadian practice setting. These recommendations are relevant for hematologists/oncologists, oncology nurses, pharmacists, nurse practitioners, physician assistants, and other providers who treat patients with multiple myeloma, as well as individuals with multiple myeloma and their care partners. These recommendations will be of interest to clinicians who treat patients with MM at community clinics and hospitals and who may be interested in referring patients for T-cell-redirecting therapy.

Equecabtagene Autoleucel in Patients With Relapsed or Refractory Multiple Myeloma: The FUMANBA-1 Nonrandomized Clinical Trial

Importance

Equecabtagene autoleucel (eque-cel), a fully human-derived B-cell maturation antigen-targeting chimeric antigen receptor (CAR) T-cell therapy, has exhibited potential for the treatment of relapsed or refractory multiple myeloma (RRMM), and further investigation in a larger cohort is necessary.

Objective

To evaluate whether eque-cel can benefit patients with RRMM and determine the overall response rate postinfusion.

Design, Setting, and Participants

The FUMANBA-1 trial was a single-arm, open-label, phase 1b/2 trial that evaluated eque-cel in adult patients with RRMM. Enrollment began in April 2020, and patients who received eque-cel will be monitored for a minimum of 15 years following the infusion. As of September 2022, patients with heavily pretreated RRMM who received at least 3 prior courses of therapy from 14 centers were enrolled. Data were analyzed from April 2020 to September 2022.

Interventions

Patients received a single infusion of eque-cel at 1.0 × 106 CAR-positive T cells/kg after the lymphodepletion.

Main Outcomes and Measures

Efficacy was the primary objective, and safety, pharmacokinetics, and pharmacodynamics were secondary objectives.

Results

Of 103 patients who received an eque-cel infusion, 55 (53.4%) were male, and the median (range) age was 58 (39-70) years. A total of 101 patients were evaluable for efficacy. At a median (range) follow-up of 13.8 (0.4-27.2) months, the overall response rate was 96.0% (97 of 101), with 74.3% (75 of 103) achieving a complete response or better. Among the 12 patients who had prior CAR T-cell treatment, 75% (9 of 12) achieved a response. The median progression-free survival was not reached, with a 12-month progression-free survival rate of 78.8% (95% CI, 68.6-86.0). A total of 96 patients (95.0%) achieved minimal residual disease negativity at a sensitivity threshold of 10-5. Adverse events were favorable: 96 of 103 patients (93.2%) experienced cytokine release syndrome (grade 1 to 2 in 95 patients [92.3%]) and 2 (1.9%) experienced immune effector cell-associated neurotoxicity syndrome (grade 1 to 2). All cases of immune effector cell-associated neurotoxicity syndrome and 94 of 96 cases of cytokine release syndrome resolved with treatment. Additionally, only 20 patients (19.4%) developed antidrug antibodies. Cellular kinetic analysis confirmed CAR-positive T cells in all patients, with the longest duration at 735 days.

Conclusions and Relevance

In this trial, eque-cel led to early, deep, and durable responses in patients with heavily pretreated RRMM with a manageable safety profile. Patients with prior CAR T-cell therapy also benefitted from eque-cel.

Trial Registration

Chinese Clinical Trial Registry Identifier: ChiCTR2000033946.

Best Practice Considerations by The American Society of Transplant and Cellular Therapy: Infection Prevention and Management After Chimeric Antigen Receptor T Cell Therapy for Hematological Malignancies

Chimeric antigen receptor (CAR) T-cell therapy is rapidly advancing, offering promising treatments for patients with hematological malignancy. However, associated infectious complications remain a significant concern because of their contribution to patient morbidity and non-relapse mortality. Recent epidemiological insights shed light on risk factors for infections after CAR T-cell therapy. However, the available evidence is predominantly retrospective, highlighting a need for further prospective studies. Institutions are challenged with managing infections after CAR T-cell therapy but variations in the approaches taken underscore the importance of standardizing infection prevention and management protocols across different healthcare settings. Therefore, the Infectious Diseases Special Interest Group of the American Society of Transplantation and Cellular Therapy assembled an expert panel to develop best practice considerations. The aim was to guide healthcare professionals in optimizing infection prevention and management for CAR T-cell therapy recipients and advocates for early consultation of Infectious Diseases during treatment planning phases given the complexities involved. By synthesizing current evidence and expert opinion these best practice considerations provide the basis for understanding infection risk after CAR T-cell therapies and propose risk-mitigating strategies in children, adolescents, and adults. Continued research and collaboration will be essential to refining and effectively implementing these recommendations.

A Primer on Chimeric Antigen Receptor T-cell Therapy-related Toxicities for the Intensivist

Chimeric antigen receptor (CAR) T-cell therapy is an innovative treatment approach that has shown remarkable efficacy against several hematologic malignancies. However, its use can be associated with unique and sometimes severe toxicities that require admission to intensive care unit in 30% of patients, and intensivists should be aware of immune-mediated toxicities of CAR T-cell therapy and management of adverse events. We will review available literature on current diagnostic criteria and therapeutic strategies for mitigating these most common toxicities associated with CAR T-cell therapy including cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) in the post-infusion period. The authors will also review other toxicities associated with CAR T-cell therapy including cytopenias, acquired immunocompromised states, and infections, and discuss the available literature on best supportive care and prophylaxis recommendations. Critical care medicine specialists play a crucial role in the management of patients undergoing CAR T-cell therapies. With the expanding use of these products in increasing numbers of treating centers, intensivists' roles as part of the multidisciplinary team caring for these patients will have an outsized impact on the continued success of these promising therapies.

Multiple myeloma and infections in the era of novel treatment modalities

Infections are major cause of morbidity and mortality in patients with multiple myeloma. Current treatment landscape of newly-diagnosed multiple myeloma includes different classes of drugs, such as proteasome inhibitors, immunomodulatory drugs, and monoclonal antibodies, all of which are characterized by specific risk and pattern of infectious complications. Additionally, autologous and allogeneic hematopoietic cell transplantation, widely used in the treatment of multiple myeloma, are complex procedures, carrying a significant risk of complications, and mainly infections. Finally, novel treatment modalities such as bispecific T-cell engagers and chimeric antigen receptor T-lymphocytes have been changing the paradigm of myeloma treatment in relapsed-refractory setting. These agents due to unique mechanism of action carry distinct pattern of infectious complications. In this review, an attempt has been made to summarize the incidence, risk factors, and patterns of infections during different stages of myeloma treatment including novel treatment modalities, and to provide evidence underlying the current concept of infectious disease prophylaxis in this category of patients.

Incidence and outcomes of cytomegalovirus reactivation after chimeric antigen receptor T-cell therapy

ABSTRACT

Cytomegalovirus (CMV) reactivation is a major complication among seropositive allogeneic hematopoietic cell transplantation recipients; however, data on CMV reactivation after chimeric antigen receptor (CAR) T-cell therapy are limited. We report the incidence and outcomes of 95 adult CMV-seropositive patients who received CAR T-cell therapy between February 2018 and February 2023. CMV outcomes were CMV reactivation (any viremia) and clinically significant CMV infection (cs-CMV). Thirty-one patients (33%) had evidence of CMV reactivation (any viremia), and 10 patients (11%) had cs-CMV. The median time from CAR T-cell infusion to CMV reactivation was 19 days (interquartile range [IQR], 9-31). The cumulative incidence of CMV (any viremia) was significantly higher among patients with grade 3 to 4 cytokine release syndrome (67 vs 28%; P = .01), and those who received corticosteroids (39 vs 21%; P = .03), anakinra (56 vs 28%; P = .02), or ≥2 immunosuppressants (41 vs 21%; P = .02). Receipt of corticosteroids (18 vs 0%; P = .004), tocilizumab (14 vs 0%; P = .04), anakinra (33 vs 7%; P = .008), and ≥2 immunosuppressants (20 vs 0%; P = .001) were all associated with cs-CMV. Receiving ≥2 immunosuppressants was associated with a twofold increase in CMV reactivation in multivariate analyses (adjusted odds ratio [aOR], 2.27; 95% confidence interval, 1.1-4.8; P = .03). Overall, the 1-year mortality was significantly higher in those with CMV reactivation (57% vs 23%; P = .001). Immunosuppression, particularly with corticosteroids, for the management of CAR T-cell toxicities, is a major risk factor for CMV reactivation.

Infectious complications in pediatric patients undergoing CD19+CD22+ chimeric antigen receptor T-cell therapy for relapsed/refractory B-lymphoblastic leukemia

Chimeric antigen receptor T-cell (CAR-T) therapy is effective in the treatment of relapsed/refractory acute B-lymphoblastic leukemia (R/R B-ALL); however, patients who receive CAR-T therapy are predisposed to infections, with considerable detrimental effects on long-term survival rates and the quality of life of patients. This study retrospectively analyzed infectious complications in 79 pediatric patients with R/R B-ALL treated with CAR-T cells at our institution. Overall, 53 patients developed 88 infections. Nine patients experienced nine infections during lymphodepletion chemotherapy, 35 experienced 41 infections during the early phase (days 0-+ 30 after infusion), and 29 experienced 38 infections during the late phase (day + 31-+ 90 after infusion). Pathogens were identified in 31 infections, including 23 bacteria, seven viruses, and one fungus. Four patients were admitted to the intensive care unit for infection and one died. In a univariate analysis, there were ten factors associated with infection, including tumor load, lymphodepleting chemotherapy, neutrophil deficiency and lymphocyte reduction, cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS), etc. In a multivariate analysis, CRS ≥ grade 3 was identified as a risk factor for infection (hazard ratio = 2.41, 95% confidence interval: 1.08-5.36, P = 0.031). Therefore, actively reducing the CRS grade may decrease the risk of infection and improve the long-term quality of life of these patients.

Cytomegalovirus (CMV) Reactivation and CMV-Specific Cell-Mediated Immunity After Chimeric Antigen Receptor T-Cell Therapy

BACKGROUND

The epidemiology of cytomegalovirus (CMV) after chimeric antigen receptor-modified T-cell immunotherapy (CARTx) is poorly understood owing to a lack of routine surveillance.

METHODS

We prospectively enrolled 72 adult CMV-seropositive CD19-, CD20-, or BCMA-targeted CARTx recipients and tested plasma samples for CMV before and weekly up to 12 weeks after CARTx. We assessed CMV-specific cell-mediated immunity (CMV-CMI) before and 2 and 4 weeks after CARTx, using an interferon γ release assay to quantify T-cell responses to IE-1 and pp65. We tested pre-CARTx samples to calculate a risk score for cytopenias and infection (CAR-HEMATOTOX). We used Cox regression to evaluate CMV risk factors and evaluated the predictive performance of CMV-CMI for CMV reactivation in receiver operator characteristic curves.

RESULTS

CMV was detected in 1 patient (1.4%) before and in 18 (25%) after CARTx, for a cumulative incidence of 27% (95% confidence interval, 16.8-38.2). The median CMV viral load (interquartile range) was 127 (interquartile range, 61-276) IU/mL, with no end-organ disease observed; 5 patients received preemptive therapy based on clinical results. CMV-CMI values reached a nadir 2 weeks after infusion and recovered to baseline levels by week 4. In adjusted models, BCMA-CARTx (vs CD19/CD20) and corticosteroid use for >3 days were significantly associated with CMV reactivation, and possible associations were detected for lower week 2 CMV-CMI and more prior antitumor regimens. The cumulative incidence of CMV reactivation almost doubled when stratified by BCMA-CARTx target and use of corticosteroids for >3 days (46% and 49%, respectively).

CONCLUSIONS

CMV testing could be considered between 2 and 6 weeks in high-risk CARTx recipients.

Improving the safety of CAR-T-cell therapy: The risk and prevention of viral infection for patients with relapsed or refractory B-cell lymphoma undergoing CAR-T-cell therapy

Chimeric antigen receptor (CAR) T-cell therapy, an innovative immunotherapeutic against relapsed/refractory B-cell lymphoma, faces challenges due to frequent viral infections. Despite this, a comprehensive review addressing risk assessment, surveillance, and treatment management is notably absent. This review elucidates immune response compromises during viral infections in CAR-T recipients, collates susceptibility risk factors, and deliberates on preventive strategies. In the post-pandemic era, marked by the Omicron variant, new and severe threats to CAR-T therapy emerge, necessitating exploration of preventive and treatment measures for COVID-19. Overall, the review provides recommendations for viral infection prophylaxis and management, enhancing CAR-T product safety and recipient survival.

Adoptive cell therapy for solid tumors beyond CAR-T: Current challenges and emerging therapeutic advances

Adoptive cellular immunotherapy using immune cells expressing chimeric antigen receptors (CARs) is a highly specific anti-tumor immunotherapy that has shown promise in the treatment of hematological malignancies. However, there has been a slow progress toward the treatment of solid tumors owing to the complex tumor microenvironment that affects the localization and killing ability of the CAR cells. Solid tumors with a strong immunosuppressive microenvironment and complex vascular system are unaffected by CAR cell infiltration and attack. To improve their efficacy toward solid tumors, CAR cells have been modified and upgraded by "decorating" and "pruning". This review focuses on the structure and function of CARs, the immune cells that can be engineered by CARs and the transformation strategies to overcome solid tumors, with a view to broadening ideas for the better application of CAR cell therapy for the treatment of solid tumors.

Toxicities, intensive care management, and outcome of chimeric antigen receptor T cells in adults: an update

BACKGROUND

Chimeric antigen receptor T cells are a promising new immunotherapy for haematological malignancies. Six CAR-T cells products are currently available for adult patients with refractory or relapsed high-grade B cell malignancies, but they are associated with severe life-threatening toxicities and side effects that may require admission to ICU.

OBJECTIVE

The aim of this short pragmatic review is to synthesize for intensivists the knowledge on CAR-T cell therapy with emphasis on CAR-T cell-induced toxicities and ICU management of complications according to international recommendations, outcomes and future issues.

Neutrophil activation and clonal CAR-T re-expansion underpinning cytokine release syndrome during ciltacabtagene autoleucel therapy in multiple myeloma

Cytokine release syndrome (CRS) is the most common complication of chimeric antigen receptor redirected T cells (CAR-T) therapy. CAR-T toxicity management has been greatly improved, but CRS remains a prime safety concern. Here we follow serum cytokine levels and circulating immune cell transcriptomes longitudinally in 26 relapsed/refractory multiple myeloma patients receiving the CAR-T product, ciltacabtagene autoleucel, to understand the immunological kinetics of CRS. We find that although T lymphocytes and monocytes/macrophages are the major overall cytokine source in manifest CRS, neutrophil activation peaks earlier, before the onset of severe symptoms. Intracellularly, signaling activation dominated by JAK/STAT pathway occurred prior to cytokine cascade and displayed regular kinetic changes. CRS severity is accurately described and potentially predicted by temporal cytokine secretion signatures. Notably, CAR-T re-expansion is found in three patients, including a fatal case characterized by somatic TET2-mutation, clonal expanded cytotoxic CAR-T, broadened cytokine profiles and irreversible hepatic toxicity. Together, our findings show that a latent phase with distinct immunological changes precedes manifest CRS, providing an optimal window and potential targets for CRS therapeutic intervention and that CAR-T re-expansion warrants close clinical attention and laboratory investigation to mitigate the lethal risk.

Managing side effects: guidance for use of immunotherapies in multiple myeloma

Chimeric antigen receptor T-cell therapy and bispecific T-cell recruiting antibodies have transformed the treatment landscape for relapsed/refractory multiple myeloma, with B-cell maturation antigen being the most common target and other targets in clinical development. However, these therapies are associated with unique and severe toxicities, including cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), delayed neurotoxicity, cytopenias, and infection. In addition, immune effector cell-associated hemophagocytic lymphohistiocytosis (HLH)-like syndrome (IEC-HS), which exhibits overlap between CRS and HLH, can be challenging to diagnose and treat. In this review, we provide an overview of toxicities associated with novel immunotherapies for treatment of multiple myeloma and describe management recommendations. The pathophysiology and risk factors behind these toxicities are not yet comprehensively understood. Based on consensus recommendations, treatment for CRS consists of tocilizumab and steroids, while treatment for ICANS includes steroids and anakinra in severe cases. Management of cytopenias and infection is similar to post-hematopoietic cell transplantation principles with antimicrobial prophylaxis, growth factor support, immunoglobulin replacement, and vaccinations. In contrast, effective treatments for delayed neurotoxicity and IEC-HS are lacking, although steroids and anakinra are commonly used. Management of all these toxicities should include a broad differential and multidisciplinary collaboration with infectious diseases, neurology, and/or critical care providers.

Recommendations on prevention of infections during chimeric antigen receptor T-cell and bispecific antibody therapy in multiple myeloma

Chimeric antigen receptor T (CAR T) cell and bispecific antibody therapies have shown unprecedented efficacy in heavily pretreated patients with multiple myeloma (MM). However, their use is associated with a significant risk of severe infections, which can be attributed to various factors such as hypogammaglobulinemia, neutropenia, lymphopenia, T-cell exhaustion, cytokine-release syndrome and immune-effector cell-associated neurotoxicity syndrome. As these therapies have been recently approved by regulatory agencies, it is crucial to establish practical guidelines for infection monitoring and prevention until robust data from prospective clinical trials become available. To address this issue, a panel of experienced investigators from the Academic Consortium to Overcome Multiple Myeloma through Innovative Trials (COMMIT) developed consensus recommendations for mitigating infections associated with CAR T-cell and bispecific antibody therapies in MM patients.

Early and Late Toxicities of Chimeric Antigen Receptor T-Cells

As chimeric antigen receptor (CAR) T-cell therapy is increasingly integrated into clinical practice across a range of malignancies, identifying and treating inflammatory toxicities will be vital to success. Early experiences with CD19-targeted CAR T-cell therapy identified cytokine release syndrome and neurotoxicity as key acute toxicities and led to unified initiatives to mitigate the influence of these complications. In this section, we provide an update on the current state of CAR T-cell-related toxicities, with an emphasis on emerging acute toxicities affecting additional organ systems and considerations for delayed toxicities and late effects.

Toxicity Profile of Chimeric Antigen Receptor T-Cell and Bispecific Antibody Therapies in Multiple Myeloma: Pathogenesis, Prevention and Management

Multiple myeloma is the second-most common hematologic malignancy in adults worldwide. Despite ongoing advancement in therapeutic modalities, it remains an incurable disease with a 5-year survival rate of approximately 50%. The recent development and introduction of anti-BCMA immunotherapies into clinical practice, including chimeric antigen receptor T-cell (CAR-T) therapies and bispecific antibodies, has radically shifted the treatment paradigm. However, despite the promising potential of these therapies for broader application, frequent and significant adverse effects have been reported, both in short- and in long-term settings, requiring increasing awareness and vigilance in the treating team, close monitoring, and prompt interventions with a multidisciplinary approach. In this review, we will discuss the toxicities associated with CAR-T cell and bispecific antibody therapies, focusing on results from major clinical studies and real-world observations. In addition, we will emphasize on effective strategies for prevention, monitoring and management, and provide expert recommendations.

A novel ACE2 decoy for both neutralization of SARS-CoV-2 variants and killing of infected cells

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) led to millions of infections and deaths worldwide. As this virus evolves rapidly, there is a high need for treatment options that can win the race against new emerging variants of concern. Here, we describe a novel immunotherapeutic drug based on the SARS-CoV-2 entry receptor ACE2 and provide experimental evidence that it cannot only be used for (i) neutralization of SARS-CoV-2 in vitro and in SARS-CoV-2-infected animal models but also for (ii) clearance of virus-infected cells. For the latter purpose, we equipped the ACE2 decoy with an epitope tag. Thereby, we converted it to an adapter molecule, which we successfully applied in the modular platforms UniMAB and UniCAR for retargeting of either unmodified or universal chimeric antigen receptor-modified immune effector cells. Our results pave the way for a clinical application of this novel ACE2 decoy, which will clearly improve COVID-19 treatment.

COVID-19 and Other Viral Infections in Patients With Hematologic Malignancies

COVID-19 and our armamentarium of strategies to combat it have evolved dramatically since the virus first emerged in late 2019. Vaccination remains the primary strategy to prevent severe illness, although the protective effect can vary in patients with hematologic malignancy. Strategies such as additional vaccine doses and now bivalent boosters can contribute to increased immune response, especially in the face of evolving viral variants. Because of these new variants, no approved monoclonal antibodies are available for pre-exposure or postexposure prophylaxis. Patients with symptomatic, mild-to-moderate COVID-19 and risk features for developing severe COVID-19, who present within 5-7 days of symptom onset, should be offered outpatient therapy with nirmatrelvir/ritonavir (NR) or in some cases with intravenous (IV) remdesivir. NR interacts with many blood cancer treatments, and reviewing drug interactions is essential. Patients with severe COVID-19 should be managed with IV remdesivir, tocilizumab (or an alternate interleukin-6 receptor blocker), or baricitinib, as indicated based on the severity of illness. Dexamethasone can be considered on an individual basis, weighing oxygen requirements and patients' underlying disease and their perceived ability to clear infection. Finally, as CD19-targeted and B-cell maturation (BCMA)-targeted chimeric antigen receptor (CAR) T-cell therapies become more heavily used for relapsed/refractory hematologic malignancies, viral infections including COVID-19 are increasingly recognized as common complications, but data on risk factors and prophylaxis in this patient population are scarce. We summarize the available evidence regarding viral infections after CAR T-cell therapy.

Infectious Complications of Targeted Therapies for Solid Cancers or Leukemias/Lymphomas

Background: Infections are well known complications of some targeted drugs used to treat solid organ cancer and hematological malignancies. Furthermore, Individual patient risk factors are associated with underlying pathologies, concomitant immunosuppressive treatment, prior treatment and use of anti-infective prophylaxis. Immune-related adverse events (irAEs) are frequent among patients treated with new targeted drugs. Objectives: In this narrative review, we present the current state of knowledge concerning the infectious complications occurring in patients treated with immune checkpoint inhibitors (ICIs), Bruton’s tyrosine kinase (BTK) inhibitors, phosphatidylinositol 3-kinase (PI3K) inhibitors, antiapoptotic protein BCL-2 inhibitors, Janus kinase inhibitors or CAR-T cell infusion. Sources: We searched for studies treating infectious complications of ICIs, BTK inhibitors, PI3K inhibitors, antiapoptotic protein BCL-2 inhibitors and CAR-T cell therapy. We included randomized, observational studies and case reports. Content: Immune-related adverse events (irAEs) are frequent among patients treated with new targeted drugs. Treatment of irAEs with corticosteroids and other immunosuppressive agents can lead to opportunistic infections. Bruton’s tyrosine kinase (BTK) inhibitors are associated with higher rate of infections, including invasive fungal infections. Implications: Infections, particularly fungal ones, are common in patients treated with BTK inhibitors even though most of the complications occurring among patients treated by ICIs or CART-cells infusion are associated with the treatment of side effects related to the use of these new treatments. The diagnosis of these infectious complications can be difficult and may require extensive investigations.

Mutations in immunodeficiency-related genes may increase the risk of infection after CAR-T-cell therapy: a report of two cases

BACKGROUND

Chimeric antigen receptor T-cell therapy (CAR-T) has yielded unprecedented efficacy in B-cell malignancies. With the increasing use of CAR-T-cell therapy, infection has become one of the major concerns after CAR-T-cell infusion. Some patients even develop refractory or recurrent infections, posing challenges in treatment, prophylactic, and monitoring strategies. However, the mechanisms underlying the development of these infections were not clear.

CASE PRESENTATION

We report two cases of infection after CAR-T-cell therapy. Patient 1, diagnosed with multiple myeloma, received anti-B-cell maturation antigen (BCMA) chimeric antigen receptor T (CAR-T)-cell therapy. He developed a refractory urinary infection lasting for over 5 weeks, which was caused by Candida albicans. Whole-exome sequencing revealed that he had an IL-17RA gene mutation. Patient 2, diagnosed with acute lymphoblastic B-cell leukaemia, received anti-CD19 and anti-CD22 CAR-T-cell cocktail therapy and remained in complete remission for over 4 years. The patient had pneumonia five times during the 4 years. Whole-exon sequencing revealed that he had a CX3CR1 gene mutation.

CONCLUSION

For patients who develop persistent or recurrent infections after CAR-T-cell therapy, it is recommended to screen for immunodeficiency-related gene mutations, and the results may contribute to the management of infections post-CAR-T treatment.

Infectious complications of chimeric antigen receptor (CAR) T-cell therapies

CAR T-cells have revolutionized the treatment of many hematological malignancies. Thousands of patients with lymphoma, acute lymphoblastic leukemia, and multiple myeloma have received this "living medicine" and achieved durable remissions. Their place in therapy continues to evolve, and there is ongoing development of new generation CAR constructs, CAR T-cells against solid tumors and CAR T-cells against chronic infections like human immunodeficiency virus and hepatitis B. A significant fraction of CAR T-cell recipients, unfortunately, develop infections. This is in part due to factors intrinsic to the patient, but also to the treatment, which requires lymphodepletion (LD), causes neutropenia and hypogammaglobulinemia and necessarily increases the state of immunosuppression of the patient. The goal of this review is to present the infectious complications of CAR T-cell therapy, explain their temporal course and risk factors, and provide recommendations for their prevention, diagnosis, and management.

Innovation in BCMA CAR-T therapy: Building beyond the Model T

Autologous chimeric antigen receptor T-cell (CAR-T) therapies targeting B-cell maturation antigen (BCMA) have revolutionized the field of multiple myeloma in the same way that the Ford Model T revolutionized the original CAR world a century ago. However, we are only beginning to understand how to improve the efficacy and usability of these cellular therapies. In this review, we explore three automotive analogies for innovation with BCMA CAR-T therapies: stronger engines, better mileage, and hassle-free delivery. Firstly, we can build stronger engines in terms of BCMA targeting: improved antigen binding, tools to modulate antigen density, and armoring to better reach the antigen itself. Secondly, we can improve "mileage" in terms of response durability through ex vivo CAR design and in vivo immune manipulation. Thirdly, we can implement hassle-free delivery through rapid manufacturing protocols and off-the-shelf products. Just as the Model T set a benchmark for car manufacturing over 100 years ago, idecabtagene vicleucel and ciltacabtagene autoleucel have now set the starting point for BCMA CAR-T therapy with their approvals. As with any emerging technology, whether automotive or cellular, the best in innovation and optimization is yet to come.

CAR-T Cell Therapy in Hematological Malignancies: Current Opportunities and Challenges

Chimeric antigen receptor T (CAR-T) cell therapy represents a major breakthrough in cancer treatment, and it has achieved unprecedented success in hematological malignancies, especially in relapsed/refractory (R/R) B cell malignancies. At present, CD19 and BCMA are the most common targets in CAR-T cell therapy, and numerous novel therapeutic targets are being explored. However, the adverse events related to CAR-T cell therapy might be serious or even life-threatening, such as cytokine release syndrome (CRS), CAR-T-cell-related encephalopathy syndrome (CRES), infections, cytopenia, and CRS-related coagulopathy. In addition, due to antigen escape, the limited CAR-T cell persistence, and immunosuppressive tumor microenvironment, a considerable proportion of patients relapse after CAR-T cell therapy. Thus, in this review, we focus on the progress and challenges of CAR-T cell therapy in hematological malignancies, such as attractive therapeutic targets, CAR-T related toxicities, and resistance to CAR-T cell therapy, and provide some practical recommendations.

Managing Hypogammaglobulinemia in Patients Treated with CAR-T-cell Therapy: Key Points for Clinicians

INTRODUCTION

The unprecedented success of chimeric antigen receptor (CAR)-T-cell therapy in the management of B-cell malignancies comes with a price of specific side effects. Healthy B-cell depletion is an anticipated 'on-target' 'off-tumor' side effect and can contribute to severe and prolonged hypogammaglobulinemia. Evidence-based guidelines for the use of immunoglobulin replacement therapy (IGRT) for infection prevention are lacking in this population.

AREAS COVERED

This article reviews the mechanisms and epidemiology of hypogammaglobulinemia and antibody deficiency, association with infections, and strategies to address these issues in CD19- and BCMA-CAR-T-cell recipients.

EXPERT OPINION

CD19 and BCMA CAR-T-cell therapy result in unique immune deficits due to depletion of specific B-lineage cells and may require different infection prevention strategies. Hypogammaglobulinemia before and after CAR-T-cell therapy is frequent, but data on the efficacy and cost-effectiveness of IGRT are lacking. Monthly IGRT should be prioritized for patients with severe or recurrent bacterial infections. IGRT may be more broadly necessary to prevent infections in BCMA-CAR-T-cell recipients and children with severe hypogammaglobulinemia irrespective of infection history. Vaccinations are indicated to augment humoral immunity and can be immunogenic despite cytopenias; re-vaccination(s) may be required. Controlled trials are needed to better understand the role of IGRT and vaccines in this population.

China's top 10 hematological advances in 2021 lists the key developments in hematology in China for that year

The China's top 10 hematological advances in 2021 was announced at the 2nd Annual Meeting of Chinese Alliance for Societies of Hematology on January 16, 2022.