Derivation and validation of a novel score for early prediction of severe CRS after CAR-T therapy in haematological malignancy patients: A multi-centre study

Chimeric antigen receptor T (CAR-T) cell therapy is highly effective in inducing complete remission in haematological malignancies. Severe cytokine release syndrome (CRS) is the most significant and life-threatening adverse effect of this therapy. This multi-centre study was conducted at six hospitals in China. The training cohort included 87 patients with multiple myeloma (MM), an external validation cohort of 59 patients with MM and another external validation cohort of 68 patients with acute lymphoblastic leukaemia (ALL) or non-Hodgkin lymphoma (NHL). The levels of 45 cytokines on days 1-2 after CAR-T cell infusion and clinical characteristics of patients were used to develop the nomogram. A nomogram was developed, including CX3CL1, GZMB, IL4, IL6 and PDGFAA. Based on the training cohort, the nomogram had a bias-corrected AUC of 0.876 (95% CI = 0.871-0.882) for predicting severe CRS. The AUC was stable in both external validation cohorts (MM, AUC = 0.907, 95% CI = 0.899-0.916; ALL/NHL, AUC = 0.908, 95% CI = 0.903-0.913). The calibration plots (apparent and bias-corrected) overlapped with the ideal line in all cohorts. We developed a nomogram that can predict which patients are likely to develop severe CRS before they become critically ill, improving our understanding of CRS biology, and may guide future cytokine-directed therapies.

Current status of CAR-T cell therapy for pediatric hematologic malignancies

Acute lymphoblastic leukemia (ALL) is the most common cancer in the pediatric population, and the long-term survival can reach 90%. However, approximately, 20% of pediatric ALL patients experience relapse and require second-line chemotherapy. This is frequently followed by hematopoietic stem cell transplantation, which can cause long-term sequelae. Recent advances in immunotherapy, such as monoclonal antibody therapy and chimeric antigen receptor (CAR)-T cell therapy, have revolutionized the treatment of relapsed and refractory ALL. Anti-CD19 CAR-T cells successfully eliminate B cell malignancies such as ALL. Tisagenlecleucel (Kymriah^®) is the first CAR-T cell immunotherapy approved by the FDA. CAR-T cell therapy can cause specific adverse events (AEs) such as cytokine release syndrome and immune effector cell-associated neurotoxicity syndrome, which are defined and graded according to the consensus grading system and treated with supportive therapies along with tocilizumab and corticosteroids. Other AEs include prolonged bone marrow suppression and hypogammaglobulinemia. Severe AEs are less common in the real-world experience than in clinical trials, probably due to better management of the patient before and during CAR-T cell therapy. The biggest challenge in CAR-T cell therapy against ALL is relapse. A high tumor burden on infusion, early loss of B cell aplasia, and minimal residual disease positivity after CAR-T cell infusion are predictive of relapse. Consolidative stem cell transplantation may improve the long-term outcome. The success of CD19 CAR-T cell therapy against B cell malignancy prompted extensive research into the use of CAR-T cells against other hematologic malignancies such as T cell leukemia or myeloid leukemia.

Adoptive Immunotherapy and High-Risk Myeloma

Despite significant improvements in the treatment of multiple myeloma (MM), it remains mostly incurable, highlighting a need for new therapeutic approaches. Patients with high-risk disease characteristics have a particularly poor prognosis and limited response to current frontline therapies. The recent development of immunotherapeutic strategies, particularly T cell-based agents have changed the treatment landscape for patients with relapsed and refractory disease. Adoptive cellular therapies include chimeric antigen receptor (CAR) T cells, which have emerged as a highly promising therapy, particularly for patients with refractory disease. Other adoptive cellular approaches currently in trials include T cell receptor-based therapy (TCR), and the expansion of CAR technology to natural killer (NK) cells. In this review we explore the emerging therapeutic field of adoptive cellular therapy for MM, with a particular focus on the clinical impact of these therapies for patients with high-risk myeloma.

Management of Relapsed-Refractory Multiple Myeloma in the Era of Advanced Therapies: Evidence-Based Recommendations for Routine Clinical Practice

Multiple myeloma (MM) is the second most common hematologic malignancy in adults worldwide. Over the past few years, major therapeutic advances have improved progression-free and overall survival, as well as quality of life. Despite this recent progress, MM remains incurable in the vast majority of cases. Patients eventually relapse and become refractory to multiple drug classes, making long-term management challenging. In this review, we will focus on the treatment paradigm of relapsed/refractory MM (RRMM) in the era of advanced therapies emphasizing the available novel modalities that have recently been incorporated into routine practice, such as chimeric antigen receptor T-cell therapy, bispecific antibodies, and other promising approaches. We will also discuss major factors that influence the selection of appropriate drug combinations or cellular therapies, such as relapse characteristics, and other disease and patient related parameters. Our goal is to provide insight into the currently available and experimental therapies for RRMM in an effort to guide the therapeutic decision-making process.

Metformin-containing hydrogel scaffold to augment CAR-T therapy against post-surgical solid tumors

Physiological barriers and immunosuppressive microenvironments of solid tumors present considerable hurdles to Chimeric antigen receptor T (CAR-T) cell therapy. Herein, we discovered that metformin, a prescribed drug for type 2 diabetes, could up-regulate the oxidative phosphorylation of CAR-T cells, increase their energy metabolism, and further promote their proliferation. Inspired by this finding, we designed a hydrogel scaffold to co-deliver metformin and CAR-T cells by adding CAR-T cells into a lyophilized alginate hydrogel containing metformin. The obtained hydrogel scaffold after being implanted into the tumor resection cavity could act as a cell reservoir to sustainably release both CAR-T cells and metformin. While the released metformin could suppress oxidative and glycolytic metabolism of cancer cells and lead to decreased tumor hypoxia, CAR-T cells would respond to metformin by markedly up-regulating oxidative metabolism and adopting a long-lived, highly activated phenotype, contributing to elevated antitumor responses. As demonstrated in several post-surgical tumor models, the proliferation and tumor-infiltration of CAR-T cells were significantly enhanced and the treatment efficacy of CAR-T cells was augmented, against both local tumors and distant abscopal tumors, while showing reduced systemic immune-related adverse effects. Our work presents a new strategy to achieve effective yet safe CAR-T therapy against solid tumors using a cell-delivery scaffold based on clinically validated drugs and biomaterials.

Hit and Run: Bilateral Massive Intraocular Lymphomatous Infiltration after CAR-T Therapy

PURPOSE

We report a case of bilateral intraocular infiltration of DLBCL after CAR-T therapy.

METHODS

Retrospective case report.

RESULTS

A 62-year-old Caucasian male with medical history of high-grade DLBCL presented with papillitis and vitritis upon completion of CAR-T therapy. Thorough infectious and diagnostic work-ups were performed. Diagnostic vitreous tap revealed intraocular lymphoma. The patient received external beam radiotherapy to both orbits with dramatic improvement in disc edema and vitritis. However, subsequent MRI showed development of intracranial metastatic disease, and the patient died within the same month.

CONCLUSION

Atypical intraocular metastasis of DLBCL may occur following CAR-T therapy and may indicate secondary changes in immunosurveillance within immune-privileged sites such as the eye.

piggyBac-transposon-mediated CAR-T cells for the treatment of hematological and solid malignancies

Since the introduction of the use of chimeric antigen receptor T-cell therapy (CAR-T therapy) dramatically changed the therapeutic strategy for B cell tumors, various CAR-T cell products have been developed and applied to myeloid and solid tumors. Although viral vectors have been widely used to produce genetically engineered T cells, advances in genetic engineering have led to the development of methods for producing non-viral, gene-modified CAR-T cells. Recent progress has revealed that non-viral CAR-T cells have a significant impact not only on the simplicity of the production process and the accessibility of non-viral vectors but also on the function of the cells themselves. In this review, we focus on piggyBac-transposon-based CAR-T cells among non-viral, gene-modified CAR-T cells and discuss their characteristics, preclinical development, and recent clinical applications.

Molecular basis and clinical application of targeted therapy in oncology

Targeted therapy and precision oncology aim to improve efficacy and minimize side effects by targeting specific molecules involved in cancer growth and spread. With the advancements in genomics, proteomics, and transcriptomics with the accessible modalities such as next-generation sequencing, circulating tumor cells, and tumor Deoxyribonucleic Acid (DNA), more number of patients are being offered the targeted therapy in form of monoclonal antibodies and various intracellular targets, specific for their tumor. The harnessing of host immunity against the cancer cells by utilizing immune-oncology agents and chimeric antigen receptor T-cell therapy has further revolutionized the management of various cancers. These agents, however, have the challenge of managing the adverse effects that are peculiar to the class of drugs and very different from the conventional chemotherapy. This review article discusses the molecular basis, diagnostics, and use of targeted therapy in oncology.

Explorations of CRISPR/Cas9 for improving the long-term efficacy of universal CAR-T cells in tumor immunotherapy

Chimeric antigen receptor (CAR) T therapy has shown remarkable success in discovering novel CAR-T cell products for treating malignancies. Despite of successful results from clinical trials, CAR-T cell therapy is ineffective for long-term disease progression. Numerous challenges of CAR-T cell immunotherapy such as cell dysfunction, cytokine-related toxicities, TGF-β resistance, GvHD risks, antigen escape, restricted trafficking, and tumor cell infiltration still exist that hamper the safety and efficacy of CAR-T cells for malignancies. The accumulated data revealed that these challenges could be overcome with the advanced CRISPR genome editing technology, which is the most promising tool to knockout TRAC and HLA genes, inhibiting the effects of dominant negative receptors (PD-1, TGF-β, and B2M), lowering the risks of cytokine release syndrome (CRS), and regulating CAR-T cell function in the tumor microenvironment (TME). CRISPR technology employs DSB-free genome editing methods that robustly allow efficient and controllable genetic modification. The present review explored the innovative aspects of CRISPR/Cas9 technology for developing next-generation/universal allogeneic CAR-T cells. The present manuscript addressed the ongoing status of clinical trials of CRISPR/Cas9-engineered CAR-T cells against cancer and pointed out the off-target effects associated with CRISPR/Cas9 genome editing. It is concluded that CAR-T cells modified by CRISPR/Cas9 significantly improved antitumor efficacy in a cost-effective manner that provides opportunities for novel cancer immunotherapies.

[Management of neurotoxicity following CAR-T cell therapy: Recommendations of the SFGM-TC]

The immune effector cell-associated syndrome (ICANS) has been described as the second most frequent specific complication following CAR-T cell therapy. The median time to the onset of neurological symptoms is five days after CAR-T infusion. ICANS can be concomitant to cytokine release syndrome but often follows the resolution of the latter. However, 10 % of patients experience delayed onset after 3 weeks of CAR-T cell infusion. The duration of symptoms is usually short, around five days if an early appropriate treatment is given. Symptoms are heterogeneous, ranging from mild symptoms quickly reversible (alterations of consciousness, deterioration in handwriting) to more serious forms with seizures or even a coma. The ICANS severity is currently based on the ASTCT score. The diagnosis of ICANS is clinical but EEG, MRI and lumbar punction can help ruling out alternative diagnoses. The first line treatment consists of high-dose corticosteroids. During the twelfth edition of practice harmonization workshops of the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC), a working group focused its work on updating the SFGM-TC recommendations on the management of ICANS. In this review we discuss the management of ICANS and other neurological toxicities in patients undergoing of CAR-T cell therapy. These recommendations apply to commercial CAR-T cells, in order to guide strategies for the management neurological complications associated with this new therapeutic approach.

Case report: Cryoablation as a novel bridging strategy prior to CAR-T cell therapy for B cell malignancies with bulky disease

Chimeric antigen receptor (CAR) T-cell therapy has emerged as a powerful immunotherapy in relapsed/refractory (R/R) hematological malignancies, especially in R/R B-cell acute lymphocytic leukemia (B-ALL), non-Hodgkin lymphoma (NHL), and multiple myeloma (MM). To prevent disease progression and reduce tumor burden during CAR-T cell manufacturing, bridging therapies prior to CAR-T cell infusion are crucial. At present, it has been demonstrated that targeted therapy, radiotherapy and autologous stem cell transplantation (ASCT) could serve as effective bridging strategies. However, whether cryoablation could serve as a novel bridging strategy is unknown. In this paper, we report 2 cases of R/R B cell malignancies with bulky disease that were successfully treated with a combination of cryoablation and CAR-T cell therapy. Patient 1 was a 65-year-old female who was diagnosed with R/R MM with extramedullary disease (EMD). She was enrolled in the anti-BCMA CAR-T cell clinical trial. Patient 2 was a 70-year-old man who presented with a subcutaneous mass in the right anterior thigh and was diagnosed with primary cutaneous diffuse large B cell lymphoma, leg type (PCLBCL-LT) 1 year ago. He failed multiline chemotherapies as well as radiotherapy. Thus, he requested anti-CD19 CAR-T cell therapy. Unfortunately, they all experienced local progression during CAR-T cell manufacturing. To rapidly achieve local tumor control and reduce tumor burden, they both received cryoablation as a bridging therapy. Patient 1 achieved a very good partial response (VGPR) 1 month after CAR-T cell infusion, and patient 2 achieved a partial response (PR) 1 month after CAR-T cell infusion. In addition, adverse effects were tolerable and manageable. Our study demonstrated the favorable safety and efficacy of combination therapy with cryoablation and CAR-T cell therapy for the first time, and it also indicates that cryoablation could serve as a novel therapeutic strategy for local tumor control in B cell malignancies.

Identifying effect modifiers of CAR-T cell therapeutic efficacy: a systematic review and individual patient data meta-analysis protocol

BACKGROUND

Chimeric antigen receptor T cell therapy (CAR-T) represents a promising and exciting new therapy for hematologic malignancies, where prognosis for relapsed/refractory patients remains poor. Encouraging results from clinical trials have often been tempered by heterogeneity in response to treatment among patients, as well as safety concerns including cytokine release syndrome. The identification of specific patient or treatment-specific factors underlying this heterogeneity may provide the key to the long-term sustainability of this complex and expensive therapy. An individual patient data meta-analysis (IPMDA) may provide potential explanations for the high degree of heterogeneity. Therefore, our objective is to perform a systematic review and IPDMA of CAR-T cell therapy in patients with hematologic malignancies to explore potential effect modifiers of CAR-T cell therapy.

METHODS AND ANALYSIS

We will search MEDLINE, Embase, and the Cochrane Central Register of Controlled Clinical Trials. Studies will be screened in duplicate at the abstract level, then at the full-text level by two independent reviewers. We will include any prospective clinical trial of CAR-T cell therapy in patients with hematologic malignancies. Our primary outcome is complete response, while secondary outcomes of interest include overall response, progression-free survival, overall survival, and safety. IPD will be collected from each included trial and, in the case of missing data, corresponding authors/study sponsors will be contacted. Standard aggregate meta-analyses will be performed, followed by the IPD meta-analysis using a one-stage approach. A modified Institute of Health Economics tool will be used to evaluate the risk of bias of included studies.

ETHICS AND DISSEMINATION

Identifying characteristics that may act as modifiers of CAR-T cell efficacy is of paramount importance and can help shape future clinical trials in the field. Results from this study will be submitted for publication in a peer-reviewed scientific journal, presented at relevant conferences and shared with relevant stakeholders.

Fatal Progression of Mutated TP53-Associated Clonal Hematopoiesis following Anti-CD19 CAR-T Cell Therapy

We present the case of a 64-year-old man diagnosed with large B-cell lymphoma who relapsed twice after standard-of-care therapy. Due to persisting cytopenia, Next generation sequencing analysis was performed, revealing a small TP53-mutated clone. As a third-line therapy, the patient was treated with CAR-T cells, which resulted in complete remission. However, this treatment also led to the expansion of the TP53-mutated clone and therapy-related myelodysplasia with a complex aberrant karyotype. This case may serve as a paradigmatic example of clonal hematopoietic progression in a patient undergoing CAR-T cell therapy, especially in the context of a TP53-mutated clone.

Amant H, Chung J, Dimitriades VR, Nakra NA. Case report: Clinical course and treatment of SARS-CoV-2 in a pediatric CAR-T cell recipient with persistent hypogammaglobulinemia

This report describes a pediatric patient who underwent chimeric antigen receptor (CAR) T-cell therapy for refractory B-cell acute lymphoblastic leukemia (B-ALL) four years prior, with resultant hypogammaglobulinemia for which he was receiving weekly subcutaneous immune globulin. He presented with persistent fever, dry cough, and a tingling sensation in his toes following a confirmed COVID-19 infection 3 weeks prior. His initial nasopharyngeal SARS-CoV-2 PCR was negative, leading to an extensive workup for other infections. He was ultimately diagnosed with persistent lower respiratory tract COVID-19 infection based on positive SARS-CoV-2 PCR from bronchoalveolar lavage (BAL) sampling. He was treated with a combination of remdesivir (antiviral) and casirivimab/imdevimab (combination monoclonal antibodies) with immediate improvement in fever, respiratory symptoms, and neurologic symptoms.

Assessment of Healthcare Resource Utilization and Hospitalization Costs in Patients With Relapsed or Refractory Follicular Lymphoma Undergoing CAR-T Cell Therapy With Tisagenlecleucel: Results From the ELARA Study

Follicular lymphoma (FL) is generally considered an indolent disease, although patients with relapsing FL experience progressively shorter durations of response to second or later lines of therapy. The ongoing ELARA trial in adult patients with relapsed/refractory (r/r) FL treated with tisagenlecleucel demonstrated an overall response rate of 86.2% and a complete response rate of 69.1%, with no treatment-related deaths. Tisagenlecleucel was administered in the outpatient setting in 18% of patients in ELARA; however, there is limited knowledge concerning the impact of inpatient versus outpatient tisagenlecleucel administration on healthcare resource utilization (HCRU) among patients with r/r FL. Here, we present the first HCRU analysis among patients with r/r FL who received tisagenlecleucel in the Phase II, single-arm, multicenter ELARA trial. HCRU was characterized using hospitalization data from day 1 to month 2 after tisagenlecleucel infusion. Information on length of stay, facility use, and discharge was assessed in patients who received tisagenlecleucel in the outpatient or inpatient setting. All costs were inflated to 2020 US dollars. As of August 3, 2021 (20-month median follow-up), 17/97 (18%) r/r FL patients were infused in an outpatient setting. Patients infused in the outpatient setting generally had favorable Eastern Cooperative Oncology Group performance status and Follicular Lymphoma International Prognostic Index scores, and less bulky disease at baseline. However, the outpatients had higher proportions of patients with grade 3A FL, primary refractory disease, and >5 lines of prior therapy compared with inpatients. Forty-one percent of patients treated in the outpatient setting did not require hospitalization within 30 days after infusion, and outpatients who did require hospitalization had a shorter average length of stay compared with inpatients (5 versus 13 days). No outpatients required intensive care unit (ICU) admission, whereas 9% of inpatients were admitted to the ICU. The mean postinfusion hospitalization costs were $7477 and $40,054 in the outpatient and inpatient settings, respectively. Efficacy between both groups was similar. Tisagenlecleucel can be safely administered to some patients in the outpatient setting, which may reduce HCRU for patients with r/r FL.

CAR-T cell therapy in multiple myeloma: Current limitations and potential strategies

Over the last decade, the survival outcome of patients with multiple myeloma (MM) has been substantially improved with the emergence of novel therapeutic agents, such as proteasome inhibitors, immunomodulatory drugs, anti-CD38 monoclonal antibodies, selective inhibitors of nuclear export (SINEs), and T cell redirecting bispecific antibodies. However, MM remains an incurable neoplastic plasma cell disorder, and almost all MM patients inevitably relapse due to drug resistance. Encouragingly, B cell maturation antigen (BCMA)-targeted chimeric antigen receptor T (CAR-T) cell therapy has achieved impressive success in the treatment of relapsed/refractory (R/R) MM and brought new hopes for R/R MM patients in recent years. Due to antigen escape, the poor persistence of CAR-T cells, and the complicated tumor microenvironment, a significant population of MM patients still experience relapse after anti-BCMA CAR-T cell therapy. Additionally, the high manufacturing costs and time-consuming manufacturing processes caused by the personalized manufacturing procedures also limit the broad clinical application of CAR-T cell therapy. Therefore, in this review, we discuss current limitations of CAR-T cell therapy in MM, such as the resistance to CAR-T cell therapy and the limited accessibility of CAR-T cell therapy, and summarize some optimization strategies to overcome these challenges, including optimizing CAR structure, such as utilizing dual-targeted/multi-targeted CAR-T cells and armored CAR-T cells, optimizing manufacturing processes, combing CAR-T cell therapy with existing or emerging therapeutic approaches, and performing subsequent anti-myeloma therapy after CAR-T cell therapy as salvage therapy or maintenance/consolidation therapy.

In Vitro Diffuse Large B-Cell Lymphoma Cell Line Models as Tools to Investigate Novel Immunotherapeutic Strategies

Despite the high incidence of diffuse large B-cell lymphoma (DLBCL), its management constitutes an ongoing challenge. The most common DLBCL variants include activated B-cell (ABC) and germinal center B-cell-like (GCB) subtypes including DLBCL with MYC and BCL2/BCL6 rearrangements which vary among each other with sensitivity to standard rituximab (RTX)-based chemoimmunotherapy regimens and lead to distinct clinical outcomes. However, as first line therapies lead to resistance/relapse (r/r) in about half of treated patients, there is an unmet clinical need to identify novel therapeutic strategies tailored for these patients. In particular, immunotherapy constitutes an attractive option largely explored in preclinical and clinical studies. Patient-derived cell lines that model primary tumor are indispensable tools that facilitate preclinical research. The current review provides an overview of available DLBCL cell line models and their utility in designing novel immunotherapeutic strategies.

It Is in the Eye of the Beholder: Ocular Ultrasound Enhanced Monitoring of Neurotoxicity after CAR-T Cell Therapy

Usually used in emergency settings, bedside sonographic measurement of optic nerve sheath diameter can aid in diagnosing elevated intracranial pressure. We report a case of a 26-year-old male hospitalized for CAR T-cell therapy with Axicabtagene Ciloleucel for treatment of relapsed diffuse large B-cell lymphoma, who developed progressive symptoms of immune effector cell-associated neurotoxicity syndrome. Fundoscopic examination suggested the presence of blurred optic disc margins. Bedside ocular ultrasound revealed wide optic nerve sheath diameters and bulging optic discs bilaterally. The patient had a ventriculostomy placed for monitoring and received treatment with steroids and mannitol, as well as tocilizumab. After 7 days in the ICU, the patient recovered with no evidence of long-term neurological deficits.

Engineering the Tumor Immune Microenvironment through Minimally Invasive Interventions

The tumor microenvironment (TME) is a unique landscape that poses several physical, biochemical, and immune barriers to anti-cancer therapies. The rapidly evolving field of immuno-engineering provides new opportunities to dismantle the tumor immune microenvironment by efficient tumor destruction. Systemic delivery of such treatments can often have limited local effects, leading to unwanted offsite effects such as systemic toxicity and tumor resistance. Interventional radiologists use contemporary image-guided techniques to locally deliver these therapies to modulate the immunosuppressive TME, further accelerating tumor death and invoking a better anti-tumor response. These involve local therapies such as intratumoral drug delivery, nanorobots, nanoparticles, and implantable microdevices. Physical therapies such as photodynamic therapy, electroporation, hyperthermia, hypothermia, ultrasound therapy, histotripsy, and radiotherapy are also available for local tumor destruction. While the interventional radiologist can only locally manipulate the TME, there are systemic offsite recruitments of the immune response. This is known as the abscopal effect, which leads to more significant anti-tumoral downstream effects. Local delivery of modern immunoengineering methods such as locoregional CAR-T therapy combined with immune checkpoint inhibitors efficaciously modulates the immunosuppressive TME. This review highlights the various advances and technologies available now to change the TME and revolutionize oncology from a minimally invasive viewpoint.

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.

Radiotherapy plus CAR-T cell therapy to date: A note for cautions optimism?

Radiotherapy (RT) is a traditional therapeutic regime that focuses on ionizing radiation, however, RT maintains largely palliative due to radioresistance. Factors such as hypoxia, the radiosensitivity of immune cells, and cancer stem cells (CSCs) all come into play in influencing the significant impact of radioresistance in the irradiated tumor microenvironment (TME). Due to the substantial advances in the treatment of malignant tumors, a promising approach is the genetically modified T cells with chimeric antigen receptors (CARs) to eliminate solid tumors. Moreover, CAR-T cells targeting CSC-related markers would eliminate radioresistant solid tumors. But solid tumors that support an immune deserted TME, are described as immunosuppressive and typically fail to respond to CAR-T cell therapy. And RT could overcome these immunosuppressive features; thus, growing evidence supports the combination of RT with CAR-T cell therapy. In this review, we provide a deep insight into the radioresistance mechanisms, advances, and barriers of CAR-T cells in response to solid tumors within TME. Therefore, we focus on how the combination strategy can be used to eliminate these barriers. Finally, we show the challenges of this therapeutic partnership.

A polyamine-centric, blood-based metabolite panel predictive of poor response to CAR-T cell therapy in large B cell lymphoma

Anti-CD19 chimeric antigen receptor (CAR) T cell therapy for relapsed or refractory (r/r) large B cell lymphoma (LBCL) results in durable response in only a subset of patients. MYC overexpression in LBCL tumors is associated with poor response to treatment. We tested whether an MYC-driven polyamine signature, as a liquid biopsy, is predictive of response to anti-CD19 CAR-T therapy in patients with r/r LBCL. Elevated plasma acetylated polyamines were associated with non-durable response. Concordantly, increased expression of spermidine synthase, a key enzyme that regulates levels of acetylated spermidine, was prognostic for survival in r/r LBCL. A broad metabolite screen identified additional markers that resulted in a 6-marker panel (6MetP) consisting of acetylspermidine, diacetylspermidine, and lysophospholipids, which was validated in an independent set from another institution as predictive of non-durable response to CAR-T therapy. A polyamine centric metabolomics liquid biopsy panel has predictive value for response to CAR-T therapy in r/r LBCL.

Identification of glioblastoma-specific antigens expressed in patient-derived tumor cells as candidate targets for chimeric antigen receptor T cell therapy

Background

New therapies for glioblastoma (GBM) are urgently needed because the disease prognosis is poor. Chimeric antigen receptor (CAR)-T cell therapy that targets GBM-specific cell surface antigens is a promising therapeutic strategy. However, extensive transcriptome analyses have uncovered few GBM-specific target antigens.

Methods

We established a library of monoclonal antibodies (mAbs) against a tumor cell line derived from a patient with GBM. We identified mAbs that reacted with tumor cell lines from patients with GBM but not with nonmalignant human brain cells. We then detected the antigens they recognized using expression cloning. CAR-T cells derived from a candidate mAb were generated and tested in vitro and in vivo.

Results

We detected 507 mAbs that bound to tumor cell lines from patients with GBM. Among them, E61 and A13 reacted with tumor cell lines from most patients with GBM, but not with nonmalignant human brain cells. We found that B7-H3 was the antigen recognized but E61. CAR-T cells were established using the antigen-recognition domain of E61-secreted cytokines and exerted cytotoxicity in co-culture with tumor cells from patients with GBM.

Conclusions

Cancer-specific targets for CAR-T cells were identified using a mAb library raised against primary GBM tumor cells from a patient. We identified a GBM-specific mAb and its antigen. More mAbs against various GBM samples and novel target antigens are expected to be identified using this strategy.

Blinatumomab Prior to CAR-T Cell Therapy-A Treatment Option Worth Consideration for High Disease Burden

The optimal bridging therapy before CAR-T cell infusion in pediatric relapsed or refractory B-cell precursor acute lymphoblastic leukemia (r/r BCP-ALL) still remains an open question. The administration of blinatumomab prior to CAR-T therapy is controversial since a potential loss of CD19+ target cells may negatively impact the activation, persistence, and, as a consequence, the efficacy of subsequently used CAR-T cells. Here, we report a single-center experience in seven children with chemorefractory BCP-ALL treated with blinatumomab before CAR-T cell therapy either to reduce disease burden before apheresis (six patients) or as a bridging therapy (two patients). All patients responded to blinatumomab except one. At the time of CAR-T cell infusion, all patients were in cytological complete remission (CR). Four patients had low positive PCR-MRD, and the remaining three were MRD-negative. All patients remained in CR at day +28 after CAR-T infusion, and six out of seven patients were MRD-negative. With a median follow-up of 497 days, four patients remain in CR and MRD-negative. Three children relapsed with CD19 negative disease: two of them died, and one, who previously did not respond to blinatumomab, was successfully rescued by stem cell transplant. To conclude, blinatumomab can effectively lower disease burden with fewer side effects than standard chemotherapeutics. Therefore, it may be a valid option for patients with high-disease burden prior to CAR-T cell therapy without clear evidence of compromising efficacy; however, further investigations are necessary.