COVID-19 and CAR-T cells: current challenges and future directions-a report from the EPICOVIDEHA survey by EHA-IDWP

A systematic review and meta-analysis of nonrelapse mortality after CAR T cell therapy

Although chimeric antigen receptor (CAR) T cell therapy represents a transformative immunotherapy, it is also associated with distinct toxicities that contribute to morbidity and mortality. In this systematic review and meta-analysis, we searched MEDLINE, Embase and CINAHL (Cochrane) for reports of nonrelapse mortality (NRM) after CAR T cell therapy in lymphoma and multiple myeloma up to March 2024. After extraction of causes and numbers of death, we analyzed NRM point estimates using random-effect models. We identified 7,604 patients across 18 clinical trials and 28 real-world studies. NRM point estimates varied across disease entities and were highest in patients with mantle-cell lymphoma (10.6%), followed by multiple myeloma (8.0%), large B cell lymphoma (6.1%) and indolent lymphoma (5.7%). Entity-specific meta-regression models for large B cell lymphoma and multiple myeloma revealed that axicabtagene ciloleucel and ciltacabtagene autoleucel were independently associated with increased NRM point estimates, respectively. Of 574 reported nonrelapse deaths, over half were attributed to infections (50.9%), followed by other malignancies (7.8%) and cardiovascular/respiratory events (7.3%). Conversely, the CAR T cell-specific side effects, immune effector cell-associated neurotoxicity syndrome/neurotoxicity, cytokine release syndrome and hemophagocytic lymphohistiocytosis, represented only a minority of nonrelapse deaths (cumulatively 11.5%). Our findings underline the critical importance of infectious complications after CAR T cell therapy and support the comprehensive reporting of NRM, including specific causes and long-term outcomes.

Late events after anti-CD19 CAR T-cell therapy for relapsed/refractory B-cell non-Hodgkin lymphoma

Background

The short-term complications from chimeric antigen receptor T-cell therapy (CART) are well characterized, but the long-term complications still need to be further investigated. Therefore, herein, we will review the currently available literature published on the late adverse events following CART.

Methods

We reviewed published data available from pivotal trials and real-world experiences with anti-CD19 CART (CART19) for adults with lymphoma. We defined late events as occurring or persisting beyond 1 month after CART infusion. We focused our literature review on the following late-event outcomes post-CART19: cytopenia, immune reconstitution, infections, and subsequent malignancies.

Results

Grade 3-4 cytopenia beyond 30 days occurs in 30%-40% of patients and beyond 90 days in 3%-22% of patients and is usually managed with growth-factor and transfusion support, along with neutropenic prophylaxis. B-cell aplasia and hypogammaglobulinemia are expected on-target off-tumor effects of CART19, 44%-53% of patients have IgG < 400 mg/dL, and approximately 27%-38% of patients receive intravenous immunoglobulin (IVIG) replacement. Infections beyond the initial month from CART19 are not frequent and rarely severe, but they are more prevalent and severe when patients receive subsequent therapies post-CART19 for their underlying disease. Late neurotoxicity and neurocognitive impairment are uncommon, and other causes should be considered. T-cell lymphoma (TCL) after CART is an extremely rare event and not necessarily related to CAR transgene. Myeloid neoplasm is not rare post-CART, but unclear causality given heavily pretreated patient population is already at risk for therapy-related myeloid neoplasm.

Conclusion

CART19 is associated with clinically significant long-term effects such as prolonged cytopenia, hypogammaglobulinemia, and infections that warrant clinical surveillance, but they are mostly manageable with a low risk of non-relapse mortality. The risk of subsequent malignancies post-CART19 seems low, and the relationship with CART19 and/or prior therapies is unclear; but regardless of the possible causality, this should not impact the current benefit-risk ratio of CART19 for relapsed/refractory B-cell non-Hodgkin lymphoma (NHL).

Chimeric antigen receptor T cell therapy for autoimmune disease

Infusion of T cells engineered to express chimeric antigen receptors (CARs) that target B cells has proven to be a successful treatment for B cell malignancies. This success inspired the development of CAR T cells to selectively deplete or modulate the aberrant immune responses that underlie autoimmune disease. Promising results are emerging from clinical trials of CAR T cells targeting the B cell protein CD19 in patients with B cell-driven autoimmune diseases. Further approaches are being designed to extend the application and improve safety of CAR T cell therapy in the setting of autoimmunity, including the use of chimeric autoantibody receptors to selectively deplete autoantigen-specific B cells and the use of regulatory T cells engineered to express antigen-specific CARs for targeted immune modulation. Here, we highlight important considerations, such as optimal target cell populations, CAR construct design, acceptable toxicities and potential for lasting immune reset, that will inform the eventual safe adoption of CAR T cell therapy for the treatment of autoimmune diseases.

Decoding the historical tale: COVID-19 impact on haematological malignancy patients-EPICOVIDEHA insights from 2020 to 2022

Background

The COVID-19 pandemic heightened risks for individuals with hematological malignancies due to compromised immune systems, leading to more severe outcomes and increased mortality. While interventions like vaccines, targeted antivirals, and monoclonal antibodies have been effective for the general population, their benefits for these patients may not be as pronounced.

Methods

The EPICOVIDEHA registry (National Clinical Trials Identifier, NCT04733729) gathers COVID-19 data from hematological malignancy patients since the pandemic's start worldwide. It spans various global locations, allowing comprehensive analysis over the first three years (2020-2022).

Findings

The EPICOVIDEHA registry collected data from January 2020 to December 2022, involving 8767 COVID-19 cases in hematological malignancy patients from 152 centers across 41 countries, with 42% being female. Over this period, there was a significant reduction in critical infections and an overall decrease in mortality from 29% to 4%. However, hospitalization, particularly in the ICU, remained associated with higher mortality rates. Factors contributing to increased mortality included age, multiple comorbidities, active malignancy at COVID-19 onset, pulmonary symptoms, and hospitalization. On the positive side, vaccination with one to two doses or three or more doses, as well as encountering COVID-19 in 2022, were associated with improved survival.

Interpretation

Patients with hematological malignancies still face elevated risks, despite reductions in critical infections and overall mortality rates over time. Hospitalization, especially in ICUs, remains a significant concern. The study underscores the importance of vaccination and the timing of COVID-19 exposure in 2022 for enhanced survival in this patient group. Ongoing monitoring and targeted interventions are essential to support this vulnerable population, emphasizing the critical role of timely diagnosis and prompt treatment in preventing severe COVID-19 cases.

Funding

Not applicable.

Managing Infection Complications in the Setting of Chimeric Antigen Receptor T cell (CAR-T) Therapy

Chimeric antigen receptor T-cell (CAR T-cell) therapy has changed the paradigm of management of non-Hodgkin's lymphoma (NHL) and Multiple Myeloma. Infection complications have emerged as a concern that can arise in the setting of therapy and lead to morbidity and mortality. In this review, we classified infection complications into three categories, pre-infusion phase from the time pre- lymphodepletion (LD) up to day zero, early phase from day of infusion to day 30 post-infusion, and late phase after day 30 onwards. Infections arising in the pre-infusion phase are closely related to previous chemotherapy and bridging therapy. Infections arising in the early phase are more likely related to LD chemo and the expected brief period of grade 3-4 neutropenia. Infections arising in the late phase are particularly worrisome because they are associated with adverse risk features including prolonged neutropenia, dysregulation of humoral and adaptive immunity with lymphopenia, hypogammaglobinemia, and B cell aplasia. Bacterial, respiratory and other viral infections, protozoal and fungal infections can occur during this time . We recommend enhanced supportive care including prompt recognition and treatment of neutropenia with growth factor support, surveillance testing for specific viruses in the appropriate instance, management of hypogammaglobulinemia with repletion as appropriate and extended antimicrobial prophylaxis in those at higher risk (e.g. high dose steroid use and prolonged cytopenia). Finally, we recommend re-immunizing patients post CAR-T based on CDC and transplant guidelines.

Efficacy of Multiple SARS-CoV-2 Vaccine Doses in Patients with B Cell Hematologic Malignancies Receiving Chimeric Antigen Receptor T Cell Therapy: A Contemporary Cohort Analysis

The mortality due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) approaches 40% in recipients of chimeric antigen receptor (CAR) T cell therapy (CAR-T). The efficacy of repeated vaccine doses, including bivalent boosters, remains unknown. We examined the efficacy of repeated vaccine doses among CAR-T recipients who received at least 2 or more vaccine doses after T cell infusion. This single-center retrospective study included adults age >18 years receiving CAR-T for relapsed/refractory (R/R) B cell hematologic malignancies targeting CD19, BCMA, or CD19 and CD20 between September 2018 through March 2022 and were alive beyond 2021 to receive incremental SARS-CoV-2 vaccine doses with available seroconversion data. Multivariable analyses were performed using the design-adjusted Cox regression and logistic regression approaches with stratification. In multivariable analysis, seroconversion rates were significantly greater with a total of 4 or more vaccine doses (odds ratio [OR], 8.22; P = .008). CAR-T recipients with other B cell hematologic malignancies had significantly lower seroconversion rates and diminished Ab titers compared to those with R/R multiple myeloma (OR, .07; P = .003). One patient died due to COVID-19 in this vaccinated study cohort, accounting for a COVID-19-attributable mortality rate of 1.7%. The results provide baseline vaccine response data in a contemporary cohort including patients with diverse group of SARS-COV2 variants and support the latest Centers for Disease Control and Prevention guidelines for repeated vaccinations directed against the prevalent variant of concern.

Real-Life Comparison of Antivirals for SARS-CoV-2 Omicron Infection in Patients With Hematologic Malignancies

BACKGROUND

We aimed to describe a cohort of hematologic patients with COVID-19 treated with antivirals early.

METHODS

Non-interventional chart review study. Comparison of baseline characteristics and outcomes in high-risk hematologic patients treated with remdesivir between December 2021 and April 2022 versus those treated with nirmatrelvir/ritonavir between May and August 2022.

RESULTS

Eighty-three patients were analyzed. Forty-two received remdesivir, and 41 nirmatrelvir/ritonavir. Patients with remdesivir were younger, vaccinated with lower number of doses, and received prior corticosteroids less frequently and sotrovimab, hyperimmune plasma and corticosteroids more often. Viral shedding median (IQR) duration was 18 (13-23) and 11 (8-21) days in the remdesivir and nirmatrelvir/ritonavir groups, respectively (p = 0.004). Median (IQR) Ct values before treatment were similar in both groups. Within 5 days of treatment, median (IQR) Ct values were 26 (23-29) and 33 (30-37) in the remdesivir and nirmatrelvir/ritonavir groups, respectively (p < 0.0001). All patients were hospitalized for remdesivir administration and only four (9.8%) in the nirmatrelvir/ritonavir group. The overall outcomes in this cohort of COVID-19 patients with Omicron variant was good, as no patient needed oxygen or ICU admission. One patient in remdesivir group died from septic shock. No severe adverse event was recorded in both treatment groups.

CONCLUSIONS

Patients with hematologic malignancies and non-severe COVID-19 who received nirmatrelvir/ritonavir experienced faster decrease in viral load and shorter viral shedding. Furthermore, besides the advantage of oral administration, nirmatrelvir/ritonavir administration reduced the need of hospital admission.

Long-term survivorship care after CAR-T cell therapy

While cytokine release syndrome and immune effector cell-associated neurotoxicity syndrome are well-recognized acute toxicities of chimeric antigen receptor (CAR) T cell therapy, these complications have become increasingly manageable by protocolized treatment algorithms incorporating the early administration of tocilizumab and corticosteroids. As CAR-T cell therapy expands to new disease indications and the number of long-term survivors steadily increases, there is growing recognition of the need to appropriately evaluate and manage the late effects of CAR-T cell therapy, including late-onset or persistent neurotoxicity, prolonged cytopenias, delayed immune reconstitution and infections, subsequent malignancies, organ dysfunction, psychological distress, and fertility implications. In this review, we provide a practical approach to the long-term survivorship care of the CAR-T cell recipient, with a focus on the optimal strategies to address the common and challenging late complications affecting this unique population.

Chimeric Antigen Receptor T-Cell Therapy in Aggressive B-Cell Lymphoma

Chimeric antigen receptor (CAR) T-cell therapy is a revolutionary therapy increasingly used in the treatment of non-Hodgkin B-cell lymphoma. This review focuses on the use of CAR T-cell therapy in aggressive B-cell lymphoma including clinical indications, known short- and long-term toxicity, mechanisms of CAR T-cell efficacy and tumor resistance, and future directions in the treatment of aggressive lymphoma with CAR T-cell therapy.

Age, successive waves, immunization, and mortality in elderly COVID-19 hematological patients: EPICOVIDEHA findings

OBJECTIVES

Elderly patients with hematologic malignancies face the highest risk of severe COVID-19 outcomes. The infection's impact on different age groups remains unstudied in detail.

METHODS

We analyzed elderly patients (age groups: 65-70, 71-75, 76-80, and >80 years old) with hematologic malignancies included in the EPICOVIDEHA registry between January 2020 and July 2022. Univariable and multivariable Cox regression models were conducted to identify factors influencing death in COVID-19 patients with hematological malignancy.

RESULTS

The study included data from 3,603 elderly patients (aged 65 or older) with hematological malignancy, with a majority being male (58.1%) and a significant proportion having comorbidities. The patients were divided into four age groups, and the analysis assessed COVID-19 outcomes, vaccination status, and other variables in relation to age and pandemic waves. The 90-day survival rate for patients with COVID-19 was 71.2%, with significant differences between groups. The pandemic waves had varying impacts, with the first wave affecting patients over 80 years old, the second being more severe in 65-70, and the third being the least severe in all age groups. Factors contributing to 90-day mortality included age, comorbidities, lymphopenia, active malignancy, acute leukemia, less than three vaccine doses, severe COVID-19, and using only corticosteroids as treatment.

CONCLUSION

These data underscore the heterogeneity of elderly hematological patients, highlight the different impacts of COVID-19 waves and the pivotal importance of vaccination, and may help in planning future healthcare efforts.

Infectious complications among CD19 CAR-T cell therapy recipients: A single-center experience

BACKGROUND

CD19 chimeric antigen receptor (CAR)-T cell therapy has emerged as an effective treatment in those with refractory or relapsed lymphoma. CD19 CAR-T cell therapy can cause direct and indirect toxic adverse effects and increased risk for infection. Infectious complications and optimal antimicrobial prophylaxis strategies are an ongoing area of investigation.

METHODS

A single-center retrospective cohort study was conducted to review recipients of CD19 CAR-T cell therapy between April 2018 and December 2020. Patient characteristics and clinical outcomes were extracted from the electronic health records.

RESULTS

Infectious complications were identified in 18/50 (36%) recipients with 31 episodes of infection. The median time to infection was 225 days (range 0-614). Bacterial infections were most common with bloodstream infection followed by sinusitis and skin and soft tissue infection. Eight viral infections were identified, most being respiratory viral illnesses. Two fungal infections were identified: Pneumocystis jirovecii pneumonia (PJP) and disseminated fusariosis. Seventeen infections (54.8%) were classified as severe: leading to death, requiring hospitalization, need for empiric intravenous antibiotics, or significant alteration in hospital course. No characteristics were found to be statistically significant risks for infection, although a trend toward significance was seen in prior autologous stem cell transplant recipients (p = .12) and those with recurrent neutropenia (p = .14). Three patients (6%) died from infection.

CONCLUSION

Infections were common after CD19 CAR-T cell therapy and occurred beyond the first year. Further multicenter studies are needed to define infectious risks and optimize antimicrobial prophylaxis recommendations in recipients of CD19 CAR-T cell therapy.

Vaccine schedule recommendations and updates for patients with hematologic malignancy post-hematopoietic cell transplant or CAR T-cell therapy

Revaccination after receipt of a hematopoietic cell transplant (HCT) or cellular therapies is a pillar of patient supportive care, with the potential to reduce morbidity and mortality linked to vaccine-preventable infections. This review synthesizes national, international, and expert consensus vaccination schedules post-HCT and presents evidence regarding the efficacy of newer vaccine formulations for pneumococcus, recombinant zoster vaccine, and coronavirus disease 2019 in patients with hematological malignancy. Revaccination post-cellular therapies are less well defined. This review highlights important considerations around poor vaccine response, seroprevalence preservation after cellular therapies, and the optimal timing of revaccination. Future research should assess the immunogenicity and real-world effectiveness of new vaccine formulations and/or vaccine schedules in patients post-HCT and cellular therapy, including analysis of vaccine response that relates to the target of cellular therapies.

COVID-19 in hematopoietic stem-cell transplant recipients: A systematic review and meta-analysis of clinical characteristics and outcomes

Patients who undergo hematopoietic stem-cell transplantation (HSCT) are more susceptible to developing severe forms of COVID-19 with an increased risk of mortality. The aim of this study was to analyze, by performing a systematic review and meta-analysis, all studies that evaluated COVID-19 in HSCT adult recipients and present clinical characteristics and outcomes. Studies were eligible for inclusion if they: (I) described the clinical characteristics of COVID-19 in adult (aged 18 years old or above) HSCT recipients; (II) described outcomes of COVID-19 in this population, mainly lethality; (III) were full-text articles. We searched MedLine, Embase, SCOPUS, LILACS and Web of Science for full-text studies that evaluated COVID-19 in adult HSCT patients until 26 Apr 2023. Two independent reviewers screened the articles and extracted the data. The Joanna Briggs Institute (JBI) Critical Appraisal Checklist for Studies Reporting Prevalence Data was used to assess quality of the included studies. Meta-analysis was performed and the pooled prevalence of severe/critical disease and of death with a 95% CI was calculated with the random-effects model. Sixteen studies were included; seven (43.7%) were multicenter. Most of the studies were from Europe (37.5%). All of them had a low risk of bias using the JBI Checklist. A total of 1186 patients were included. Allogeneic HSCT patients were the majority in most studies, with a total of 861 patients (72.5%). The symptomatic rate was 79.4%. The pooled prevalence of severe/critical COVID-19 was 24.0% (95% CI 0.13-0.36; I2  = 94%; n = 334/990). The pooled prevalence of death for the entire population was 17% (95% CI 0.13-0.22; I2  = 76%; n = 221/1117), 17% (95% CI 0.12-0.23; I2  = 67%; n = 152/822) for allogeneic-HSCT and 14% (95% CI 0.08-0.22; I4  = 65%; n = 48/293) for autologous-HSCT. In conclusion, frequently the infection of SARS-CoV-2 in HSCT was symptomatic and lethality is higher than in general population. Thus, it is essential to focus on the implementation of measures to mitigate the risk of SARS-CoV-2 infection in this population, as well as to carefully assess HSCT recipients who develop COVID-19.

Evaluation of pulmonary abnormalities in recipients of hematopoietic cell transplants and cellular therapies

Hematopoietic cell transplant (HCT) and chimeric antigen receptor T-cell (CAR-T) therapy recipients are susceptible to multiple pulmonary complications that are caused by infectious and noninfectious processes. Numerous variables can be associated with specific pulmonary diseases including time from transplantation, presence of graft versus host disease (GVHD), underlying disease, and prolonged neutropenia and lymphocytopenia. Most pulmonary complications are infectious in origin, with bacterial pneumonia remaining the most common pulmonary infection, particularly before neutrophil engraftment. Invasive fungal infections continue to affect this patient population even when antifungal prophylaxis is used. Noninfectious pulmonary complications include a wide differential of pathologies in this population, and as clinical presentations of these various pulmonary disorders often overlap, clinicians frequently will use a multidisciplinary approach in diagnosing these abnormalities. Radiography, particularly with chest computed tomography (CT) imaging, is an essential tool in identifying pulmonary pathology and potential sources. While standard microbiological cultures of respiratory specimens are still utilized, their role is limited by low sensitivity and diagnostic yield. The likelihood of obtaining a diagnosis can be improved by using other microbiological assays, including fungal antigen tests and molecular diagnostic methods, particularly if specimens are collected via bronchoscopy. This review will highlight the more common causes of pulmonary diseases encountered after HCT and CAR-T and will examine the different methods in their diagnosis.

COVID-19 after hematopoietic cell transplantation and chimeric antigen receptor (CAR)-T-cell therapy

More than 3 years have passed since Coronavirus disease 2019 (COVID-19) was declared a global pandemic, yet COVID-19 still severely impacts immunocompromised individuals including those treated with hematopoietic cell transplantation (HCT) and chimeric antigen receptor-T-cell therapies who remain at high risk for severe COVID-19 and mortality. Despite vaccination efforts, these patients have inadequate responses due to immunosuppression, which underscores the need for additional preventive approaches. The optimal timing, schedule of vaccination, and immunological correlates for protective immunity remain unknown. Antiviral therapies used early during disease can reduce mortality and severity due to COVID-19. The combination or sequential use of antivirals could be beneficial to control replication and prevent the development of treatment-related mutations in protracted COVID-19. Despite conflicting data, COVID-19 convalescent plasma remains an option in immunocompromised patients with mild-to-moderate disease to prevent progression. Protracted COVID-19 has been increasingly recognized among these patients and has been implicated in intra-host emergence of SARS-CoV-2 variants. Finally, novel SARS-CoV2-specific T-cells and natural killer cell-boosting (or -containing) products may be active against multiple variants and are promising therapies in immunocompromised patients.

Omicron related COVID-19 prevention and treatment measures for patients with hematological malignancy and strategies for modifying hematologic treatment regimes

The Omicron variant of SARS-CoV-2 has rapidly become the dominant strain worldwide due to its high transmissibility, although it appears to be less pathogenic than previous strains. However, individuals with hematological malignancy (HM) and COVID-19 remain susceptible to severe infection and mortality, especially those with chronic lymphocytic leukemia (CLL) and those undergoing chimeric antigen receptor T-cell (CAR-T) treatment. Hematologists should thoroughly assess the severity of the patient's hematological disease and the potential risk of SARS-CoV-2 infection before initiating chemotherapy or immunosuppressive treatment. Vaccination and booster doses are strongly recommended and patients with a poor vaccine response may benefit from long-acting COVID-19 neutralizing monoclonal antibodies (such as Evusheld). Early use of small molecule antiviral drugs is recommended for managing mild COVID-19 in HM patients and those with severe immunodeficiency may benefit from SARS-CoV-2 neutralizing monoclonal antibody therapy and high-titer COVID-19 convalescent plasma (CCP). For moderate to severe cases, low-dose glucocorticoids in combination with early antiviral treatment can be administered, with cytokine receptor antagonists or JAK inhibitors added if the condition persists or worsens. In the treatment of hematological malignancies, delaying chemotherapy is preferable for CLL, acute leukemia (AL), and low-risk myelodysplastic syndrome (MDS), but if the disease progresses, appropriate adjustments in dosage and frequency of treatment are required, with the avoidance of anti-CD20 monoclonal antibody, CAR-T and hematopoietic stem cell transplantation (HSCT). Patients with chronic myelocytic leukemia (CML) and myeloproliferative neoplasms (MPNs) can continue current treatment. What's more, non-drug protective measures, the development of new vaccines and antiviral drugs, and monitoring of mutations in immunocompromised populations are particularly important.

[Characteristics and impact factors of SARS-CoV-2 infection in adult patients with relapsed/refractory B-cell non-Hodgkin lymphoma receiving chimeric antigen receptor T-cell therapy]

Objective: To explore the clinical characteristics and treatment of COVID-19 infection in patients with relapsed/refractory B-cell non-Hodgkin lymphoma before and after receiving chimeric antigen receptor T-cell therapy, and study the influencing factors of severe COVID-19 infection in these patients. Methods: The data of 59 patients with relapsed/refractory B-cell non-Hodgkin lymphoma who received chimeric antigen receptor T-cell therapy at the Department of Hematology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology and Department of Hematology, the Second Affiliated Hospital, College of Medicine, Zhejiang University between December 2017 and February 2023, and who were infected with novel coronavirus between December 2022 and February 2023 were retrospectively studied. Patients were divided into light, medium, severe, and critical groups, and the differences between the groups were analyzed using the chi-square test. A univariate logistic regression model was used to evaluate the contribution of each variable and its relationship with severe infection. The chi-square and Fisher's exact tests were used to analyze the differences between the B-cell aplasia and B-cell recovery (BCR) groups. Results: Of the 59 pre- and post-infusion infections, 39 (66.1%) led to mild COVID-19, 9 (15.3%) resulted in moderate COVID-19, 10 (16.9%) resulted in severe COVID-19, and 1 (1.7%) led to critical COVID-19. Moroever, age greater than 55 years, having received autologous hematopoietic stem cell transplantation, progressive disease status, and B-cell aplasia at the time of diagnosis of COVID-19 infection are factors affecting severe infection. Patients with B-cell aplasia had a more severe infection with COVID-19 (P<0.001), a longer duration (P=0.015), a longer antiviral therapy course (P<0.001), and a higher hospitalization rate (P<0.001) than the BCR group. Conclusion: Active prevention and treatment of COVID-19 infection remains a crucial issue requiring urgent attention in managing patients with relapsed/refractory B-cell non-Hodgkin lymphoma treated with chimeric antigen receptor T-cell therapy.

Infectious complications during monoclonal antibodies treatments and cell therapies in Acute Lymphoblastic Leukemia

Infections represent one of the most frequent complications during the treatment of patients with Acute Lymphoblastic Leukemia (ALL): of these, almost half develop an infectious event in the majority of cases in induction. The new monoclonal and bispecific antibodies and CAR-T, besides offering new perspectives in the overall survival and disease-free survival of patients, may also transform the epidemiology of infections in ALL by improving the toxicity of treatments. In this review, we examined studies published in the literature over the past 12 years and described the infectious complications of therapy with Blinatumomab, Inotuzumab, Rituximab and CAR-T in adult and pediatric patients with ALL. Infections are less frequent than in traditional chemotherapy treatment with vincristine, corticosteroids and anthracyclines, which has been the backbone of therapy for patients with ALL for years. On the other hand, the infection scenario in the CAR-T setting is quite peculiar: In these patients, infections are more frequent in the first month after infusion and are predominantly bacterial. As the time moves away from day zero, viral infections become more frequent, occurring mainly in patients who have had prolonged cytopenia and major cytokine release syndrome.

Multidisciplinary recommendations for the management of CAR-T recipients in the post-COVID-19 pandemic era

The outbreak of coronavirus disease 2019 (COVID-19) posed an unprecedented challenge on public health systems. Despite the measures put in place to contain it, COVID-19 is likely to continue experiencing sporadic outbreaks for some time, and individuals will remain susceptible to recurrent infections. Chimeric antigen receptor (CAR)-T recipients are characterized by durable B-cell aplasia, hypogammaglobulinemia and loss of T-cell diversity, which lead to an increased proportion of severe/critical cases and a high mortality rate after COVID-19 infection. Thus, treatment decisions have become much more complex and require greater caution when considering CAR T-cell immunotherapy. Hence, we reviewed the current understanding of COVID-19 and reported clinical experience in the management of COVID-19 and CAR-T therapy. After a panel discussion, we proposed a rational procedure pertaining to CAR-T recipients with the aim of maximizing the benefit of CAR-T therapy in the post COVID-19 pandemic era.

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.

Current outcomes of SARS-CoV-2 Omicron variant infection in high-risk haematological patients treated early with antivirals

OBJECTIVES

We aimed to describe the clinical outcomes and duration of viral shedding in high-risk patients with haematological malignancies hospitalized with COVID-19 during Omicron variant predominance who received early treatment with antivirals.

METHODS

We conducted a prospective observational study on high-risk haematological patients admitted in our hospital between December 2021 and March 2022. We performed detection techniques on viral subgenomic mRNAs until negative results were obtained to document active, prolonged viral replication.

RESULTS

This analysis included 60 consecutive adults with high-risk haematological malignancies and COVID-19. All of these patients underwent early treatment with remdesivir. Thirty-two (53%) patients received combined antiviral strategies, with sotrovimab or hyperimmune plasma being added to remdesivir. The median length of viral replication-as measured by real-time RT-PCR and/or subgenomic RNA detection-was 20 (IQR 14-28) days. Prolonged viral replication (6 weeks after diagnosis) was documented in six (10%) patients. Only two patients had prolonged infection for more than 2 months. Overall mortality was 5%, whereas COVID-19-related mortality was 0%.

CONCLUSIONS

Current outcomes of high-risk patients with haematological malignancies hospitalized with COVID-19 during Omicron variant predminance are good with the use of early antiviral strategies. Persistent viral shedding is uncommon.

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.

Long-term outcomes following CAR T cell therapy: what we know so far

Chimeric antigen receptors (CAR) are engineered fusion proteins designed to target T cells to antigens expressed on cancer cells. CAR T cells are now an established treatment for patients with relapsed and/or refractory B cell lymphomas, B cell acute lymphoblastic leukaemia and multiple myeloma. At the time of this writing, over a decade of follow-up data are available from the initial patients who received CD19-targeted CAR T cells for B cell malignancies. Data on the outcomes of patients who received B cell maturation antigen (BCMA)-targeted CAR T cells for multiple myeloma are more limited owing to the more recent development of these constructs. In this Review, we summarize long-term follow-up data on efficacy and toxicities from patients treated with CAR T cells targeting CD19 or BCMA. Overall, the data demonstrate that CD19-targeted CAR T cells can induce prolonged remissions in patients with B cell malignancies, often with minimal long-term toxicities, and are probably curative for a subset of patients. By contrast, remissions induced by BCMA-targeted CAR T cells are typically more short-lived but also generally have only limited long-term toxicities. We discuss factors associated with long-term remissions, including the depth of initial response, malignancy characteristics predictive of response, peak circulating CAR levels and the role of lymphodepleting chemotherapy. We also discuss ongoing investigational strategies designed to improve the length of remission following CAR T cell therapy.

Respiratory Viral Infections in Recipients of Cellular Therapies: A Review of Incidence, Outcomes, Treatment, and Prevention

Respiratory viral infections (RVIs) are of major clinical importance in immunocompromised patients and represent a substantial cause of morbidity and mortality in patients with hematologic malignancies and those who have undergone hematopoietic cell transplantation. Similarly, patients receiving immunotherapy with CD19-targeted chimeric antigen receptor-modified T cells, natural killer cells, and genetically modified T-cell receptors are susceptible to RVIs and progression to lower respiratory tract infections. In adoptive cellular therapy recipients, this enhanced susceptibility to RVIs results from previous chemotherapy regimens such as lymphocyte-depleting chemotherapy conditioning regimens, underlying B-cell malignancies, immune-related toxicities, and secondary prolonged, profound hypogammaglobulinemia. The aggregated risk factors for RVIs have both immediate and long-term consequences. This review summarizes the current literature on the pathogenesis, epidemiology, and clinical aspects of RVIs that are unique to recipients of adoptive cellular therapy, the preventive and therapeutic options for common RVIs, and appropriate infection control and preventive strategies.

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.

Emergency department use by patients who received chimeric antigen receptor T cell infusion therapy

Background

Chimeric antigen receptor T cell infusion (CAR T) therapy has revolutionized the treatment of hematologic malignancies, but treatment-related toxicities are of concern. Understanding the timing and reasons for which patients present to the emergency department (ED) after CAR T therapy can assist with the early recognition and management of toxicities.

Methods

A retrospective observational cohort study was conducted for patients who had undergone CAR T therapy in the past 6 months and visited the ED of The University of Texas MD Anderson Cancer Center between 04/01/2018 and 08/01/2022. The timing of presentation after CAR T product infusion, patient characteristics, and outcomes of the ED visit were examined. Survival analyses were conducted using Cox proportional hazards regression and Kaplan-Meier estimates.

Results

During the period studied, there were 276 ED visits by 168 unique patients. Most patients had diffuse large B-cell lymphoma (103/168; 61.3%), multiple myeloma (21/168; 12.5%), or mantle cell lymphoma (16/168; 9.5%). Almost all 276 visits required urgent (60.5%) or emergent (37.7%) care, and 73.5% of visits led to admission to the hospital or observation unit. Fever was the most frequent presenting complaint, reported in 19.6% of the visits. The 30-day and 90-day mortality rates after the index ED visits were 17.0% and 32.2%, respectively. Patients who had their first ED visit &gt;14 days after CAR T product infusion had significantly worse overall survival (multivariable hazard ratio 3.27; 95% confidence interval 1.29–8.27; P=0.012) than patients who first visited the ED within 14 days of CAR T product infusion.

Conclusion

Cancer patients who receive CAR T therapy commonly visit the ED, and most are admitted and/or require urgent or emergent care. During early ED visits patients mainly present with constitutional symptoms such as fever and fatigue, and these early visits are associated with better overall survival.

B-cell malignancies and COVID-19: a narrative review

BACKGROUND

COVID-19 has been extensively characterized in immunocompetent hosts and to a lesser extent in immunocompromised populations. Among the latter, patients treated for B-cell malignancies have immunosuppression generated by B-cell lymphodepletion/aplasia resulting in an increased susceptibility to respiratory virus infections and poor response to vaccination. The consequence is that these patients are likely to develop severe or critical COVID-19.

OBJECTIVES

To examine the overall impact of COVID-19 in patients treated for a B-cell malignancy or receiving chimeric antigen receptor T (CAR-T) immunotherapy administered in case of relapsed or refractory disease.

SOURCES

We searched in the MEDLINE database to identify relevant studies, trials, reviews, or meta-analyses focusing on SARS-CoV-2 vaccination or COVID-19 management in patients treated for a B-cell malignancy or recipients of CAR-T cell therapy up to 8 July 2022.

CONTENT

The epidemiology and outcomes of COVID-19 in patients with B-cell malignancy and CAR-T cell recipients are summarized. Vaccine efficacy in these subgroups is compiled. Considering the successive surges of variants of concern, we propose a critical appraisal of treatment strategies by discussing the use of neutralizing monoclonal antibodies, convalescent plasma therapy, direct-acting antiviral drugs, corticosteroids, and immunomodulators.

IMPLICATIONS

For patients with B-cell malignancy, preventive vaccination against SARS-CoV-2 remains essential and the management of COVID-19 includes control of viral replication because of protracted SARS-CoV-2 shedding. Passive immunotherapy (monoclonal neutralizing antibody therapy and convalescent plasma therapy) and direct-active antivirals, such as remdesivir and nirmatrelvir/ritonavir are the best currently available treatments. Real-world data and subgroup analyses in larger trials are warranted to assess COVID-19 therapeutics in B-cell depleted populations.

Rehabilitation of patients after CAR T-cell therapy. Experiences on 5 patients

OBJECTIVE

CAR T-cell therapy is an effective treatment for various relapsed or refractory haemato-oncological diseases. However, this therapy results in significant immunosuppression that lasts for months. Whether these patients are at risk during a rehabilitation stay, e.g., due to infections, has not yet been answered.

METHODS

We describe the rehabilitation stay under special hygienic conditions of the five patients rehabilitated in our clinic after CAR T-cell therapy. Complications that occurred during rehabilitation are reported, as well as the positive effects of rehabilitation on physical performance, polyneuropathic complaints, anxiety and depression, and individual limitations.

RESULTS

One patient reported signs of infection already at the beginning of rehabilitation. This was treated with antibiotics, and rehabilitation could be continued. No complications occurred in any of the other patients. All patients reported having benefited physically and psychologically from the rehabilitation, and two expressed the intention to return to work.

CONCLUSIONS

As far as we know, this is the first report on several patients after CAR T-cell therapy. Based on the limited data, there is no reason to withhold a rehabilitation stay from patients after CAR T-cell therapy.

SARS-CoV-2 infections in pediatric and young adult recipients of chimeric antigen receptor T-cell therapy: an international registry report

BACKGROUND

Immunocompromised patients are at increased risk of SARS-CoV-2 infections. Patients undergoing chimeric antigen receptor (CAR) T-cell therapy for relapsed/refractory B-cell malignancies are uniquely immunosuppressed due to CAR T-mediated B-cell aplasia (BCA). While SARS-CoV-2 mortality rates of 33%-40% are reported in adult CAR T-cell recipients, outcomes in pediatric and young adult CAR T-cell recipients are limited.

METHODS

We created an international retrospective registry of CAR T recipients aged 0-30 years infected with SARS-CoV-2 within 2 months prior to or any time after CAR T infusion. SARS-CoV-2-associated illness was graded as asymptomatic, mild, moderate, or severe COVID-19, or multisystem inflammatory syndrome in children (MIS-C). To assess for risk factors associated with significant SARS-CoV-2 infections (infections requiring hospital admission for respiratory distress or supplemental oxygen), univariate and multivariable regression analyses were performed.

RESULTS

Nine centers contributed 78 infections in 75 patients. Of 70 SARS-CoV-2 infections occurring after CAR T infusion, 13 (18.6%) were classified as asymptomatic, 37 (52.9%) mild, 11 (15.7%) moderate, and 6 (8.6%) severe COVID-19. Three (4.3%) were classified as MIS-C. BCA was not significantly associated with infection severity. Prior to the emergence of the Omicron variant, of 47 infections, 19 (40.4%) resulted in hospital admission and 7 (14.9%) required intensive care, while after the emergence of the Omicron variant, of 23 infections, only 1 (4.3%) required admission and the remaining 22 (95.7%) had asymptomatic or mild COVID-19. Death occurred in 3 of 70 (4.3%); each death involved coinfection or life-threatening condition. In a multivariable model, factors associated with significant SARS-CoV-2 infection included having two or more comorbidities (OR 7.73, CI 1.05 to 74.8, p=0.048) and age ≥18 years (OR 9.51, CI 1.90 to 82.2, p=0.014). In the eight patients infected with SARS-CoV-2 before CAR T, half of these patients had their CAR T infusion delayed by 15-30 days.

CONCLUSIONS

In a large international cohort of pediatric and young adult CAR-T recipients, SARS-CoV-2 infections resulted in frequent hospital and intensive care unit admissions and were associated with mortality in 4.3%. Patients with two or more comorbidities or aged ≥18 years were more likely to experience significant illness. Suspected Omicron infections were associated with milder disease.

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.

Supportive Care for Patients with Lymphoma Undergoing CAR-T-cell Therapy: the Advanced Practice Provider's Perspective

PURPOSE OF REVIEW

The purpose of our paper is to describe the all-encompassing supportive care for patients with relapsed or refractory lymphoma undergoing cellular therapy, with a focus on the advanced practice provider's (APPs) perspective.

RECENT FINDINGS

Chimeric antigen receptor-T (CAR-T) cell therapy has become more available for treating relapsed or refractory B-cell hematologic malignancies, requiring proficient and adequate treatment of side effects, complications, and infections that may occur during therapy. APPs often meet these patients during the initial referral and help to support them through the CAR-T cell therapy process. As APPs acquire a complete understanding and comprehensive knowledge of how to treat, support, and guide patients with B-cell malignancies through CAR-T cell therapy, they play a pivotal role in these patients throughout their treatment. Standardization of supportive care is paramount.

CAR T-Cell Therapy for Patients with Multiple Myeloma: Current Evidence and Challenges

The therapeutic landscape of multiple myeloma (MM) has benefited from an emergence of novel therapies over the last decade. By inducing T-cell kill of target cancer cells, chimeric antigen receptor (CAR) T-cell therapies have improved outcomes of patients with hematologic malignancies. B-cell maturation antigen (BCMA) is the current target antigen of choice for most CAR T-cell products under investigation for MM. However, their shortcomings deal with logistical and clinical challenges, including limited availability, manufacturing times, and toxicities. This article provides an overview of recently developed and investigational CAR T-cell therapies for MM, highlighting current evidence and challenges.

Serologic response and safety of COVID-19 vaccination in HSCT or CAR T-cell recipients: a systematic review and meta-analysis

Background

Patients receiving hematopoietic stem cell transplantation (HSCT) or chimeric antigen receptor T cell (CAR T-cell) therapy are immunocompromised and at high risk of viral infection, including SAR2-CoV-2 infection. However, the effectiveness and safety of COVID-19 vaccines in these recipients is not well characterized. The present meta-analysis evaluated the serologic response and safety of COVID-19 vaccines in these population.

Methods

Literature databases (MEDLINE, EMBASE, Web of Science, MedRvix and BioRvix) were searched for original studies with serologic response post COVID-19 vaccination in HSCT or CAR T-cell recipients published until July 14, 2022. The analysis included 27 observational studies with a total of 2899 patients receiving allogeneic HSCT (2506), autologous HSCT (286) or CAR T-cell therapy (107), and 683 healthy participants with serologic response data. Random effects models were used to pool the rate of serologic response to COVID-19 vaccination in HSCT or CAR T-cell recipients and odds ratio comparing with healthy controls.

Results

The pooled seropositivity rates in HSCT and CAR T-cell recipients were 0.624 [0.506–0.729] for one dose, 0.745 [0.712–0.776] for two doses. The rates were significantly lower than those in healthy controls (nearly 100%). In subgroup analysis, CAR T-cell recipients exhibited an even lower seroconversion rate (one dose: 0.204 [0.094–0.386]; two doses: 0.277 [0.190–0.386]) than HSCT counterparts (one dose: 0.779 [0.666–0.862]; two doses: 0.793 [0.762–0.821]). The rates were comparable between autologous and allogeneic HSCT recipients. Other possible impact factors related to seropositivity were time interval between therapy and vaccination, use of immunosuppressive drugs and immune cell counts. Most vaccine-related adverse effects were mild and resolvable, comparable to general population.

Conclusions

This analysis revealed a diminished response to COVID-19 vaccines in HSCT or CAR T-cell recipients. Our findings may inform regular COVID-19 vaccination at appropriate intervals after HSCT or CAR T-cell therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40164-022-00299-6.

The burden of SARS-CoV-2 in patients receiving chimeric antigen receptor T cell immunotherapy: everything to lose

INTRODUCTION

Chimeric antigen receptor T (CAR-T) cell immunotherapy has revolutionized the prognosis of refractory or relapsed B-cell malignancies. CAR-T cell recipients have immunosuppression generated by B-cell aplasia leading to a higher susceptibility to respiratory virus infections and poor response to vaccination.

AREAS COVERED

This review focuses on the challenge posed by B-cell targeted immunotherapies: managing long-lasting B-cell impairment during the successive surges of a deadly viral pandemic. We restricted this report to data regarding vaccine efficacy in CAR-T cell recipients, outcomes after developing COVID-19 and specificities of treatment management. We searched in MEDLINE database to identify relevant studies until March 31^st 2022.

EXPERT OPINION

Among available observational studies, the pooled mortality rate reached 40% in CAR-T cell recipients infected by SARS-CoV-2. Additionally, vaccines responses seem to be widely impaired in recipients (seroconversion 20%, T-cell response 50%). In this setting of B-cell depletion, passive immunotherapy is the backbone of treatment. Convalescent plasma therapy has proven to be a highly effective curative treatment with rare adverse events. Neutralizing monoclonal antibodies could be used as pre-exposure prophylaxis or early treatment but their neutralizing activity is constantly challenged by new variants. In order to reduce viral replication, direct-acting antiviral drugs should be considered.

Infectious complications, immune reconstitution, and infection prophylaxis after CD19 chimeric antigen receptor T-cell therapy

CD19-targeted chimeric antigen receptor (CAR) T-cell becomes a breakthrough therapy providing excellent remission rates and durable disease control for patients with relapsed/refractory (R/R) hematologic malignancies. However, CAR T-cells have several potential side effects including cytokine release syndrome, neurotoxicities, cytopenia, and hypogammaglobulinemia. Infection has been increasingly recognized as a complication of CAR T-cell therapy. Several factors predispose CAR T-cell recipients to infection. Fortunately, although studies show a high incidence of infection post-CAR T-cells, most infections are manageable. In contrast to patients who undergo hematopoietic stem cell transplant, less is known about post-CAR T-cell immune reconstitution. Therefore, evidence regarding antimicrobial prophylaxis and vaccination strategies in these patients is more limited. As CAR T-cell therapy becomes the standard treatment for R/R B lymphoid malignancies, we should expect a larger impact of infections in these patients and the need for increased clinical attention. Studies exploring infection and immune reconstitution after CAR T-cell therapy are clinically relevant and will provide us with a better understanding of the dynamics of immune function after CAR T-cell therapy including insights into appropriate strategies for prophylaxis and treatment of infections in these patients. In this review, we describe infections in recipients of CAR T-cells, and discuss risk factors and potential mitigation strategies.

Vaccine-induced T-cell responses against SARS-CoV-2 and its Omicron variant in patients with B cell-depleted lymphoma after CART therapy

Patients receiving CD19 CAR T-cell therapy for relapsed/refractory lymphoma experience prolonged and profound B-cell aplasia and hypogammaglobulinemia, placing them at a higher risk for severe COVID-19. Independently, Oh et al and Atanackovic et al demonstrate that despite attenuated humoral response to mRNA-based vaccines, patients demonstrate normal or heightened functional T-cell responses, including antiviral T-cell activity against SARS-CoV-2 variants including Omicron. Collectively, these data reinforce the importance of COVID-19 vaccination following CD19 CAR T-cell therapy, despite long-term B-cell aplasia.

COVID-19 outcomes in children, adolescents and young adults with cancer

Pediatric oncology patients are at risk for poor outcomes with respiratory viral infections. Outcome data for COVID‐19 in children and young adults with cancer are needed; data are sparse for obese/overweight and adolescent and young adult subgroups. We conducted a single center cohort study of COVID‐19 outcomes in patients younger than 25 years with cancer. Candidate hospitalization risk factors were analyzed via univariable and multivariable analyses. Eighty‐seven patients with cancer and COVID‐19 were identified. Most were Hispanic/Latinx (n = 63, 72%). Forty‐two (48%) were overweight/obese. Anticancer therapy included chemotherapy only (n = 64, 74%), chimeric antigen receptor T‐cells (CAR‐T, n = 7), hematopoietic stem cell transplantation (HSCT, n = 12), or CAR‐T and HSCT (n = 4). There was no COVID‐19 related mortality. Twenty‐six patients (30%) required COVID‐19 related hospitalization; 4 required multiple hospitalizations. Nine (10%) had severe/critical infection; 6 needed intensive care. COVID‐19 resulted in anticancer therapy delays in 22 (34%) of 64 patients on active therapy (median delay = 14 days). Factors associated with hospitalization included steroids within 2 weeks prior to infection, lymphopenia, previous significant non‐COVID infection, and low COVID‐19 PCR cycle threshold value. CAR‐T recipients with B‐cell aplasia tended to have severe/critical infection (3 of 7 patients). A COVID‐19 antibody response was detected in 14 of 32 patients (44%). A substantial proportion of COVID‐19 infected children and young adults with cancer require inpatient management; morbidity may be high in B‐cell immunodeficiency. However, a majority of patients can be taken through chemotherapy without prolonged therapy delays. Viral load is a potential outcome predictor in COVID‐19 in pediatric cancer.

T cell responses against SARS-CoV-2 and its Omicron variant in a patient with B cell lymphoma after multiple doses of a COVID-19 mRNA vaccine

Anti-SARS-CoV-2 antibodies are crucial for protection from future COVID-19 infections, limiting disease severity, and control of viral transmission. While patients with the most common type of hematologic malignancy, B cell lymphoma, often develop insufficient antibody responses to messenger RNA (mRNA) vaccines, vaccine-induced T cells would have the potential to ‘rescue’ protective immunity in patients with B cell lymphoma. Here we report the case of a patient with B cell lymphoma with profound B cell depletion after initial chemoimmunotherapy who received a total of six doses of a COVID-19 mRNA vaccine. The patient developed vaccine-induced anti-SARS-CoV-2 antibodies only after the fifth and sixth doses of the vaccine once his B cells had started to recover. Remarkably, even in the context of severe treatment-induced suppression of the humoral immune system, the patient was able to mount virus-specific CD4⁺ and CD8⁺ responses that were much stronger than what would be expected in healthy subjects after two to three doses of a COVID-19 mRNA vaccine and which were even able to target the Omicron ‘immune escape’ variant of the SARS-CoV-2 virus. These findings not only have important implications for anti-COVID-19 vaccination strategies but also for future antitumor vaccines in patients with cancer with profound treatment-induced immunosuppression.

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.