CAR T-Cell Therapy Is Effective but Not Long-Lasting in B-Cell Lymphoma of the Brain

Anti-CD19 CAR T-cell therapy for primary and secondary CNS lymphomas

Central nervous system lymphomas (CNSL) are a heterogeneous group of generally aggressive tumors whose prognosis varies significantly, being more favorable in patients with primary disease and poorer in those with secondary lymphoma. Current treatments typically involve intensive chemotherapy followed by consolidation with autologous stem cell transplantation or whole-brain radiotherapy. However, if the disease relapses, there is no established standard of care. The recent approval of anti-CD19 chimeric antigen receptor (CAR) T-cell therapy for systemic B-cell lymphomas has shifted the treatment landscape for previously incurable patients. Even though this therapy was initially underexplored in the setting of CNSL due to safety and efficacy concerns, it could offer a new therapeutic avenue for these patients. In this review, we will provide a concise overview of the current treatment strategies for CNSL, highlighting their key limitations, including relapse rates and long-term toxicity. Following this, we will explore the most important studies and clinical trials on CNSL, focusing on recent advancements in anti-CD19 CAR T-cell therapy. This comprehensive analysis will offer insights into the successes and challenges of treating CNSL effectively.

CAR-T cell therapy in the treatment of relapsed or refractory primary central nervous system lymphoma: recent advances and challenges

Primary central nervous system lymphoma (PCNSL) is a rare and aggressive lymphoma that is isolated in the central nervous system (CNS) or vitreoretinal space. High-dose methotrexate (HD-MTX)-based immunochemotherapy is the frontline for its treatment, with a high early response rate. However, relapsed or refractory (R/R) patients present numerous difficulties and challenges in clinical treatment. Chimeric antigen receptor (CAR)-T cells offer a promising option for the treatment of hematologic malignancies, especially in the R/R B-cell lymphoma and multiple myeloma. Despite the exclusion of most PCNSL cases from pivotal CAR-T cell trials due to their specific tumor microenvironment (TME), available preclinical and clinical studies with small cohorts suggest an overall acceptable safety profile and remarkable anti-tumor effects. In this review, we will provide the development process of CAR-T cells and summarize the research progress, limitations, and future perspectives of CAR-T cell therapy in patients with R/R PCNSL.

Epileptic seizures in patients with primary central nervous system lymphoma: A systematic review

BACKGROUND

Primary central nervous system lymphoma (PCNSL) accounts for less than 5% of primary brain tumors. Epileptic seizures are a common manifestation of brain tumors; however, literature on the prevalence, characteristics, and oncological implications of seizures in patients with PCNSL is limited, and the management of antiepileptic drugs (AEDs) is unclear. This review aimed to summarize the existing knowledge on seizures in PCNSL, their potential association with surgery, oncological treatment, survival rates, and management of AEDs.

METHODS

A systematic review was performed according to the PRISMA recommendations and included articles published between 1953 and 2023 describing seizures in patients with PCNSL.

RESULTS

The search identified 282 studies, of which 21 were included. Up to 33% of patients with PCNSL developed seizures, mostly at the initial presentation. Little information was found on changes in seizure incidence through the course of the disease, and no details were found on seizure frequency, the percentage of treatment-resistant patients, or the evolution of seizures at remission. Younger age, cortical location, and immunodeficiency have been identified as potential risk factors for seizures, but evidence is very limited. The growing use of vigorous treatments including intensive chemotherapy with autologous stem cell transplantation and immunotherapy with CAR-T cells is associated with a higher incidence of seizures. The association between seizure development and patient mortality in PCNSL remains unknown. There are no data on AED prophylaxis or the use of specific AEDs in PCNSL.

CONCLUSIONS

Further studies are needed to investigate seizures in larger cohorts of PCNSL, to clarify their prevalence, better characterize them, identify risk factors, analyze survival rates, and make recommendations on AED management. We recommend following general practice guidelines for seizures symptomatic of brain tumors and not to prescribe AED prophylaxis in PCNSL.

Molecular Mechanisms and Therapeutic Prospects of Immunotherapy and Targeted Therapy in Primary Central Nervous System Lymphoma

Primary central nervous system lymphoma (PCNSL) is a very rare extranodal non-Hodgkin's lymphoma confined to the brain, eyes, spinal cord, and cerebrospinal fluid (CSF). This disease is highly aggressive. For decades, high-dose methotrexate-based induction regimens have been the standard treatment for PCNSL and have significantly improved patient overall survival (OS). However, some patients still experience disease recurrence or develop drug resistance. With a deeper understanding of the pathophysiology of PCNSL, various therapies, including CD20 monoclonal antibodies, Bruton's tyrosine kinase (BTK) inhibitors, immunomodulatory drugs, immune checkpoint inhibitors, phosphoinositide 3-kinase (PI3 K)/mammalian target of rapamycin(mTOR) inhibitors, and chimeric antigen receptor (CAR) -T cells are increasingly being applied and have demonstrated considerable efficacy. These therapies have paved the way for novel treatment strategies in PCNSL, representing a highly promising field. Investigating the mechanisms, specific targets, and signaling pathways, as well as interactions with the tumor microenvironment (TME), can provide a solid foundation for further exploration and potentially enhance the optimization of treatment approaches for PCNSL. This review seeks to explore the characteristics of the TME in PCNSL, elucidate the molecular mechanisms of various immunotherapies and targeted therapies, examine their interactions with the TME, and summarize the advancements in the research of PCNSL immunotherapy and targeted therapy.

CD19/CD22 CAR-T-cell cocktail therapy following autologous transplantation is an optimizing strategy for treating relapsed/refractory central nervous system lymphoma

Relapsed/refractory (R/R) primary and secondary central nervous system lymphomas (PCNSL, SCNSL) are associated with short survival and represent an unmet need, requiring novel effective strategies. We retrospectively compared the safety and efficacy of CD19/22 CAR-T-cell therapy following ASCT (ASCT + CAR-T group), CD19/22 CAR-T-cell cocktail therapy (CAR-T group) and chemoimmunotherapy (CIT group) in treating R/R CNSL patients. Analysis of the differences in clinical characteristics among the three groups revealed that the median age in the CIT group was older than that in the ASCT + CAR-T group and CAR-T group, and the median number of prior lines of therapy in the CIT group was less than that in the other groups. Patients in the two CAR-T-therapy groups exhibited comparable incidences and severities of CRS and ICANS. Grade 4-5 CRS and ICANS were not observed in either CAR-T-cell therapy group. The incidence of Grade 3/4 hematological toxicity in the ASCT + CAR-T and CAR-T groups was greater than that in the CIT group. The ORR was 82.75% in the ASCT + CAR-T group, 60.00% in the CAR-T group and 58.83% in the CIT group. As of December 31, 2022, the median follow-up after therapy was 16.73 months (range, 0.67-42.00 months). The median durations of PFS and OS were not reached in the ASCT + CAR-T group. The median PFS in the CAR-T group was 4.72 months, and OS was not reached. In the CIT group, the median PFS and OS were 6.63 months and 16.77 months, respectively. The 2-year PFS rate of patients in the ASCT + CAR-T group (65.52%) was significantly greater than that of patients in the CAR-T group (30.00%, P = 0.0321) and CIT group (23.53%, P = 0.0043). Our results support the development of CAR-T-cell therapy for R/R CNSL. With the durability of remission and low toxicity, ASCT combined with CAR-T-cell therapy appears to be a more effective and safer treatment option for primary and secondary R/R CNS lymphoma.

CNS bridging radiotherapy achieves rapid cytoreduction before CAR T-cell therapy for aggressive B-cell lymphomas

ABSTRACT

Chimeric antigen receptor (CAR) T-cell therapy (CART) for central nervous system lymphoma (CNSL) is a promising strategy, yet responses are frequently not durable. Bridging radiotherapy (BRT) is used for extracranial lymphoma in which it can improve CART outcomes through cytoreduction of high-risk lesions. We hypothesized that BRT would achieve similar, significant cytoreduction before CART for CNSL (CNS-BRT). We identified patients with CNSL with non-Hodgkin B-cell lymphoma who received CNS-BRT before commercial CART. Cytoreduction from CNS-BRT was calculated as change in lesion size before CART. Twelve patients received CNS-BRT, and the median follow-up among survivors is 11.8 months (interquartile range, 8.5-21.9). Ten patients had CNSL (9 secondary, 1 primary) and 2 patients had epidural disease (evaluable for toxicity). All 10 patients with CNSL had progressive disease at the time of CNS-BRT. Of 12 patients, 1 experienced grade ≥3 cytokine release syndrome, and 3 of 12 patients experienced grade ≥3 immune effector cell-associated neurotoxicity syndrome. CNS-BRT achieved a 74.0% (95% confidence interval, 62.0-86.0) mean reduction in lesion size from baseline (P = .014) at a median of 12 days from BRT completion and before CART infusion. Best CNS response included 8 complete responses, 1 partial response, and 1 progressive disease. Three patients experienced CNS relapse outside the BRT field. Preliminary data suggest CNS-BRT achieves rapid cytoreduction and is associated with a favorable CNS response and safety profile. These data support further study of BRT as a bridging modality for CNSL CART.

Updates of primary central nervous system lymphoma

Lymphoma occurring in the central nervous system is considered primary central nervous system lymphoma (PCNSL), usually without systematic lesions. Over the last few decades, a deep understanding of PCNSL has been lacking due to the low incidence rate, and the overall survival and progression-free survival of patients with PCNSL are lower than those with other types of non-Hodgkin lymphoma. Recently, there have been several advancements in research on PCNSL. Advances in diagnosis of the disease are primarily reflected in the promising diagnostic efficiency of novel biomarkers. Pathogenesis mainly involves abnormal activation of nuclear factor kappa-B signaling pathways, copy number variations, and DNA methylation. Novel therapies such as Bruton's tyrosine kinase inhibitors, immunomodulatory drugs, immune checkpoint inhibitors, and phosphoinositide 3-kinase/mammalian target of rapamycin inhibitors are being evaluated as possible treatment options for PCNSL, especially for relapsed/refractory (R/R) cases. Several clinical trials also indicated the promising feasibility and efficacy of chimeric antigen receptor T-cell therapy for selected R/R PCNSL patients. This review focuses on discussing recent updates, including the diagnosis, pathogenesis, and novel therapy of PCNSL.

Real-world experience of commercial relmacabtagene autoleucel (relma-cel) for relapsed/refractory central nervous system lymphoma: a multicenter retrospective analysis of patients in China

BACKGROUND

Relapsed/refractory (R/R) central nervous system lymphomas (CNSLs) are associated with a poor prognosis. Relmacabtagene autoleucel (relma-cel), expressing the same chimeric antigen receptor (CAR) as lisocabtagene maraleucel, with an optimized commercial-ready process developed in China, demonstrated remarkable efficacy and manageable safety in the pivotal RELIANCE study. However, no published data are available on the "real-world" use of relma-cel, especially for patients with CNS involvement.

PATIENTS AND METHODS

Retrospective analyses were conducted for commercial relma-cel used in patients with R/R CNSL at 12 clinics. The primary endpoint was to evaluate the proportion of patients who achieved complete response (CR) at 3 months. Secondary endpoints included best complete response (BCR), progression-free survival (PFS), duration of response (DOR), overall survival (OS), and the incidence of adverse events.

RESULTS

Among the 22 CNSL patients (12 primary CNSLs; 10 secondary CNSLs), the best overall response rate was 90.9% and the BCR rate was 68.2%. With median follow-up of 316 days (range, 55-618 days), the estimated 1-year PFS rate, DOR, and OS rate were 64.4%, 71.5%, and 79.2%, respectively. Significant clinical benefits were observed in patients who were in durable CR or partial response to the most recent prior therapy preleukapheresis and received relma-cel as consolidation therapy (n=8), with 1-year PFS rate of 100.0% versus 41.7% (p=0.02). In addition, in terms of primary endpoint, non-CR at 3 months postinfusion seemed to be predictive of a worse prognosis, with an estimated 1-year PFS of 83.3% versus 37.0% (p=0.03), respectively. CRS occurred in 72.9% of patients (grade 3: 4.5%) and immune effector cell-associated neurotoxicity syndrome in 36.4% of patients (grade 3: 4.5%). With the add-on agent PD-1 inhibitor (tislelizumab) to the ongoing BTKi, significant re-expansions of CAR T-cell were detected by quantitative PCR or flow cytometry after a median of 2 weeks (range, 12-32 days).

CONCLUSIONS

This study was the first and largest real-world study of commercial relma-cel for R/R CNSL, demonstrating promising efficacy and acceptable safety. We reaffirmed the benefit of immuno-agents such as BTKi or PD-1 inhibitor on CAR T-cell re-expansion and hypothesized a dual-agent CAR-T related combinatorial therapies, which warrants further validation. Most importantly, we highlighted the earlier use of CAR T-cell therapy as a consolidative therapy for patients sensitive to salvage therapy, which provided an impetus and inspired-future strategy.

Sustained efficacy of chimeric antigen receptor T-cell therapy in central nervous system lymphoma: a systematic review and meta-analysis of individual data

Background: Central nervous system lymphoma (CNSL) is considered an aggressive lymphoma with a poor prognosis. Studies investigating CNSL have shown that chimeric antigen receptor (CAR) T-cell therapy has demonstrated an effective response in limited sample sizes. Therefore, we conducted this systematic review and meta-analysis to clarify the sustained efficacy and factors associated with the sustained efficacy of CAR T-cell therapy in the treatment of CNSL. Methods: We searched studies from PubMed, Embase, Medline, and the Cochrane Center Register of Controlled Trials up to July 2023. Studies that included individual data on the duration of response (DoR) after receiving CAR T-cell therapy were enrolled. Pooled response rates were calculated using fixed-effects or random-effects models. Subgroup analysis was performed to analyze the heterogeneity, and a Cox regression model was performed to identify the factors associated with sustained efficacy. Results: In total, 12 studies including 69 patients were identified and included in this meta-analysis. The pooled relapse rate was 45% [95% CI 35, 56]. Subgroup analyses of relapse rates revealed that CAR T-cells using the CD28/4-1BB domain (CD28/4-1BB vs. CD28 vs. 4-1BB, p = 0.0151), parenchymal or leptomeningeal involvement (parenchymal or leptomeningeal vs. both parenchymal and leptomeningeal, p < 0.0001), and combined treatment with CAR T-cell therapy [Autologous stem cell transplantation (ASCT) plus CAR T-cell therapy vs. CAR T cells with maintenance therapy vs. CAR T-cell therapy alone, p = 0.003] were associated with lower relapse rates in patients. Time-to-event endpoints were assessed using reconstructed individual patient survival data to explore key modulators of DoR. Partial response status at CAR-T infusion and the use of ASCT plus CAR T-cell therapy were associated with longer DoR at the multivariate level, with hazard ratios of 0.25 and 0.26, respectively. Conclusion: CAR T-cell therapy shows promising and sustained efficacy in CNSL patients. However, further prospective large-scale studies are needed to assess these effect modifiers to optimize patient selection and improve the sustained efficacy of CAR T-cell therapy in the treatment of CNSL. Systematic review registration: https://clinicaltrials.gov/, identifier PROSPERO CRD42023451856.

Leptomeningeal disease in melanoma: An update on the developments in pathophysiology and clinical care

Leptomeningeal disease (LMD) remains a major challenge in the clinical management of metastatic melanoma patients. Outcomes for patient remain poor, and patients with LMD continue to be excluded from almost all clinical trials. However, recent trials have demonstrated the feasibility of conducting prospective clinical trials in these patients. Further, new insights into the pathophysiology of LMD are identifying rational new therapeutic strategies. Here we present recent advances in the understanding of, and treatment options for, LMD from metastatic melanoma. We also annotate key areas of future focus to accelerate progress for this challenging but emerging field.

Chimeric Antigen Receptor-T Cell Therapy for Lymphoma: New Settings and Future Directions

In the last decade, anti-CD19 CAR-T cell therapy has led to a treatment paradigm shift for B-cell non-Hodgkin lymphomas, first with the approval for relapsed/refractory (R/R) large B-cell lymphomas and subsequently for R/R mantle cell and follicular lymphoma. Many efforts are continuously being made to extend the therapeutic setting in the lymphoma field. Several reports are supporting the safety and efficacy of CAR-T cells in patients with central nervous system disease involvement. Anti-CD30 CAR-T cells for the treatment of Hodgkin lymphoma are in development and early studies looking for the optimal target for T-cell malignancies are ongoing. Anti-CD19/CD20 and CD19/CD22 dual targeting CAR-T cells are under investigation in order to increase anti-lymphoma activity and overcome tumor immune escape. Allogeneic CAR product engineering is on the way, representing a rapidly accessible 'off-the-shelf' and potentially more fit product. In the present manuscript, we will focus on recent advances in CAR-T cell therapy for lymphomas, including new settings and future perspectives in the field, reviewing data reported in literature in the last decade up to October 2023.

Branched-chain keto acids promote an immune-suppressive and neurodegenerative microenvironment in leptomeningeal disease

Leptomeningeal disease (LMD) occurs when tumors seed into the leptomeningeal space and cerebrospinal fluid (CSF), leading to severe neurological deterioration and poor survival outcomes. We utilized comprehensive multi-omics analyses of CSF from patients with lymphoma LMD to demonstrate an immunosuppressive cellular microenvironment and identified dysregulations in proteins and lipids indicating neurodegenerative processes. Strikingly, we found a significant accumulation of toxic branched-chain keto acids (BCKA) in the CSF of patients with LMD. The BCKA accumulation was found to be a pan-cancer occurrence, evident in lymphoma, breast cancer, and melanoma LMD patients. Functionally, BCKA disrupted the viability and function of endogenous T lymphocytes, chimeric antigen receptor (CAR) T cells, neurons, and meningeal cells. Treatment of LMD mice with BCKA-reducing sodium phenylbutyrate significantly improved neurological function, survival outcomes, and efficacy of anti-CD19 CAR T cell therapy. This is the first report of BCKA accumulation in LMD and provides preclinical evidence that targeting these toxic metabolites improves outcomes.

Long-term Complete Remission of Decitabine-Primed Tandem CD19/CD22 CAR-T Therapy with PD-1 and BTK Inhibitors Maintenance in a Refractory Primary Central Nervous System Lymphoma Patient

Primary central nervous system lymphoma (PCNSL) is a rare and aggressive non-Hodgkin's lymphoma that affects the brain, eyes, cerebrospinal fluid, or spinal cord without systemic involvement. The outcome of patients with PCNSL is worse compared to patients with systemic diffuse large B-cell lymphoma. Given potential mortality associated with severe immune effector cell-associated neurotoxicity syndrome (ICANS), patients with PCNSL have been excluded from most clinical trials involving chimeric antigen receptor T-cell (CAR-T) therapy initially. Here, we report for the first time to apply decitabine-primed tandem CD19/CD22 dual-targeted CAR-T therapy with programmed cell death-1 (PD-1) and Bruton's tyrosine kinase (BTK) inhibitors maintenance in one patient with multiline-resistant refractory PCNSL and the patient has maintained complete remission (CR) for a 35-month follow-up period. This case represents the first successful treatment of multiline resistant refractory PCNSL with long-term CR and without inducing ICANS under tandem CD19/CD22 bispecific CAR-T therapy followed by maintenance therapy with PD-1 and BTK inhibitors. This study shows tremendous potential in the treatment of PCNSL and offers a look toward ongoing clinical studies.

CAR T-cell-associated neurotoxicity in central nervous system hematologic disease: Is it still a concern?

Chimeric antigen receptor (CAR) T-cell systemic immunotherapy has revolutionized how clinicians treat several refractory and relapsed hematologic malignancies. Due to its peculiar mechanism of action, CAR T-cell-based therapy has enlarged the spectrum of neurological toxicities. CAR T-cell-associated neurotoxicity-initially defined as CAR T-cell-related encephalopathy syndrome (CRES) and currently coined within the acronym ICANS (immune effector cell-associated neurotoxicity syndrome)-is perhaps the most concerning toxicity of CAR T-cell therapy. Importantly, hematologic malignancies (especially lymphoid malignancies) may originate in or spread to the central nervous system (CNS) in the form of parenchymal and/or meningeal disease. Due to the emergence of deadly and neurological adverse events, such as fatal brain edema in some patients included in early CAR T-cell trials, safety concerns for those with CNS primary or secondary infiltration arose and contributed to the routine exclusion of individuals with pre-existing or active CNS involvement from pivotal trials. However, based primarily on the lack of evidence, it remains unknown whether CNS involvement increases the risk and/or severity of CAR T-cell-related neurotoxicity. Given the limited treatment options available for patients once they relapse with CNS involvement, it is of high interest to explore the role of novel clinical strategies including CAR T cells to treat leukemias/lymphomas and myeloma with CNS involvement. The purpose of this review was to summarize currently available neurological safety data of CAR T-cell-based immunotherapy from the clinical trials and real-world experiences in adult patients with CNS disease due to lymphoma, leukemia, or myeloma. Increasing evidence supports that CNS involvement in hematologic disease should no longer be considered per se as an absolute contraindication to CAR T-cell-based therapy. While the incidence may be high, severity does not appear to be impacted significantly by pre-existing CNS status. Close monitoring by trained neurologists is recommended.

Toxicity and efficacy of CAR T-cell therapy in primary and secondary CNS lymphoma: a meta-analysis of 128 patients

Relapsed/refractory primary central nervous system lymphoma (PCNSL) and secondary central nervous system lymphoma (SCNSL) are associated with short survival and represent an unmet need, requiring novel effective strategies. Anti-CD19 chimeric antigen receptor (CAR) T cells, effective in systemic large B-cell lymphoma (LBCL), have shown responses in PCNSL and SCNSL in early reports, but with limited sample size. We, therefore, performed a comprehensive systematic review and meta-analysis of all published data describing CAR T-cell use in PCNSL and SCNSL. This identified 128 patients with PCNSL (30) and SCNSL (98). Our primary objectives were to evaluate CAR T-cell specific toxicity (immune effector cell-associated neurotoxicity syndrome [ICANS] and cytokine release syndrome [CRS]) as well as response rates in these 2 populations. Seventy percent of patients with PCNSL had CRS of any grade (13% grade 3-4) and 53% had ICANS of any grade (18% grade 3-4). Comparatively, 72% of the SCNSL cohort experienced CRS of any grade (11% grade 3-4) and 48% had ICANS of any grade (26% grade 3-4). Of the patients with PCNSL, 56% achieved a complete remission (CR) with 37% remaining in remission at 6 months. Similarly, 47% of patients with SCNSL had a CR, with 37% in remission at 6 months. In a large meta-analysis of central nervous system (CNS) lymphomas, toxicity of anti-CD19-CAR T-cell therapy was similar to that of registrational studies in systemic LBCL with no increased signal of neurotoxicity observed. Encouraging efficacy was demonstrated in patients with CNS lymphoma with no discernible differences between PCNSL and SCNSL.

Is CD19-directed chimeric antigen receptor T cell therapy a smart strategy to combat central nervous system lymphoma?

Primary central nervous system lymphoma (PCNSL) is a rare form and aggressive type of diffuse large B-cell lymphoma (DLBCL) that occurs in both immunocompetent and immunocompromised adults. While adding rituximab to chemotherapeutic regimens resulted in dramatic improvement in both progression-free survival and overall survival in patients with non-central nervous system (CNS) DLBCL, the outcomes of PCNSL are generally poor due to the immune-privileged tumor microenvironment or suboptimal delivery of systemic agents into tumor tissues. Therefore, more effective therapy for PCNSL generally requires systemic therapy with sufficient CNS penetration, including high-dose intravenous methotrexate with rituximab or high-dose chemotherapy followed by autologous stem cell transplantation. However, overall survival is usually inferior in comparison to non-CNS lymphomas, and treatment options are limited for elderly patients or patients with relapsed/refractory disease. Chimeric antigen receptor T (CAR-T) cell therapy has emerged as a cutting-edge cancer therapy, which led to recent FDA approvals for patients with B-cell malignancies and multiple myeloma. Although CAR-T cell therapy in patients with PCNSL demonstrated promising results without significant toxicities in some small cohorts, most cases of PCNSL are excluded from the pivotal CAR-T cell trials due to the concerns of neurotoxicity after CAR-T cell infusion. In this review, we will provide an overview of PCNSL and highlight current approaches, resistance mechanisms, and future perspectives of CAR-T cell therapy in patients with PCNSL.

Radiotherapy or chemotherapy: a real-world study of the first-time relapsed and refractory primary central nervous system lymphoma

Background

Primary central nervous system lymphoma (PCNSL) is an uncommon variant of non-Hodgkin lymphoma (NHL) with high aggressiveness and poor prognosis. Although complete remission (CR) could be achieved with therapy, some patients remain refractory or recurrently with a worse response to salvage treatment and poor prognosis. No consensus on rescue therapy has been established currently. This study is aimed to evaluate the efficacy of radiotherapy or chemotherapy in first-time relapsed or refractory progressed PCNSL (R/R PCNSL) and analysis the prognostic factors, to explore differences between relapsed and refractory PCNSL.

Methods

Totally 105 R/R PCNSL patients from Huashan Hospital between 1 January 2016 and 31 December 2020 were enrolled, underwent salvage radiotherapy or chemotherapy and received response assessments after each course. PFS1 was defined as the time from diagnosis to the first time of recurrence or refractory progression. Statistical analysis was performed with SPSS version 26.0.

Results

Response and survival were analyzed over a 17.5months (median) follow-up. Compared to relapsed PCNSL (n = 42), refractory PCNSL (n = 63) had a shorter median PFS1 related to deep lesions. 82.4% of cases were discovered as the second relapse or progression. ORR and PFS were both higher in relapsed PCNSL than those in refractory PCNSL. ORR of radiotherapy in both relapsed and refractory PCNSL was higher than that of chemotherapy. Elevated CSF protein and ocular involvement were related to PFS and OS after recurrence respectively in relapsed PCNSL. Age ≥ 60y was unfavorable to OS-R (OS after recurrence or progression) in refractory PCNSL.

Conclusions

Our results indicate that relapsed PCNSL responds well to inducing and salvage therapy and has a better prognosis compared to refractory PCNSL. Radiotherapy is effective for PCNSL after the first relapse or progression. Age, CSF protein level, and ocular involvement could be potential factors to predict prognosis.

Chimeric Antigen Receptor T-Cell (CAR T-Cell) Therapy for Primary and Secondary Central Nervous System Lymphoma: A Systematic Review of Literature

Relapsed/refractory central nervous system (CNS) lymphoma, whether primary or secondary, is associated with poor prognosis with currently available treatment modalities, including high-dose chemotherapy-autologous stem cell transplantation. The pivotal ZUMA-1 and JULIET trials that led to FDA approval of Axicabtagene ciloleucel and Tisagenlecleucel for relapsed refractory large cell lymphoma excluded patients with CNS involvement due to concerns of increased toxicity. However, TRANSCEND study for Lisocabtagene maraleucel in relapsed refractory large cell lymphoma allowed patients with CNS involvement and reported manageable CNS toxicities in these patients. In the real-world experience, chimeric antigen receptor T-cell (CAR T) therapy has been deemed safe and effective for these patients with poor prognosis. In this systematic review, we analyzed available literature to evaluate the role of CAR T-cell therapy in both primary and secondary CNS lymphoma using Embase, Cochrane, and PubMed databases. A total of 14 studies, including 8 retrospective analyses and 6 prospective studies/clinical trials, were included in the qualitative synthesis to study the safety and efficacy of CAR T. Based on our analysis, CAR T-cell therapy appears to be associated with reasonable efficacy and a manageable safety for primary and secondary CNS lymphoma.

Efficacy and safety of chimeric antigen receptor T-cells treatment in central nervous system lymphoma: a PRISMA-compliant single-arm meta-analysis

BACKGROUND

Chimeric antigen receptor (CAR) T cells are used to treat refractory and recurrent B-cell lymphoma. When administered intravenously, CAR T cells can be detected in cerebrospinal fluid, and thus represent a promising method for the treatment of central nervous system lymphoma (CNSL). This meta-analysis aimed to clarify the effectiveness and safety of CAR T-cell therapy in the treatment of CNSL.

METHODS

Studies involving patients with CNSL who received CAR T-cell therapy that reported overall response (OR), complete response (CR), and partial response (PR) were included. A random-effects or fixed-effects model with double arcsine transformation was used for the pooled analysis and 95% confidence intervals (CI) were determined for all outcomes.

RESULTS

Eight studies, comprising 63 patients, were identified and were included in the meta-analysis. The pooled OR and CR rates after treatment with CAR T cells were 69% (95% CI, 56-81%) and 51% (95% CI, 37-64%), respectively. The pooled rate of progressive disease after remission was 38% (95% CI, 21-55%). The pooled rate for neurotoxicity grade 3 or above was 12% (95% CI, 3-24%, I² = 0.00%, p = 0.53). No treatment-related deaths were reported.

CONCLUSIONS

CAR T-cell therapy is a promising option for the treatment of CNSL owing to a high short-term remission rate and controllable side effects. However, the high recurrence rate after remission must be addressed. Long-term follow-up data with large sample sizes are also needed to better assess the effectiveness and safety of CAR T-cell therapy.

REGISTRATION

This meta-analysis was registered in the international prospective register of systematic reviews (PROSPERO) (CRD42022301332).

A Case of Relapsed Primary Central Nervous System Lymphoma Treated with CD19-directed Chimeric Antigen Receptor T Cell Therapy

Although high-dose methotrexate (HD-MTX) is the standard therapy for primary central nervous system lymphoma (PCNSL), the prognosis remains poor. Because 90% of PCNSL is diffuse large B-cell lymphoma (DLBCL), chimeric antigen receptor (CAR)-T cell therapy is expected to be beneficial. However, there are limited reports on CAR-T cell therapy for PCNSL because of the concern of neurotoxicity. Here, we report a case of relapsed PCNSL treated with anti-CD19 CAR-T cell therapy. A 40-year-old woman presenting with visual disturbance in her left eye was initially diagnosed with bilateral uveitis. Her histological diagnosis was DLBCL, and she was positive for CD19. Although she received chemotherapy including HD-MTX, the tumor relapsed in her right occipital lobe. She underwent remission induction therapy and then anti-CD19 CAR-T cell therapy. Cytokine release syndrome (CRS) grade 2 occurred, but there were no complications of CAR-T cell-related encephalopathy syndrome (CRES). She has achieved complete response for more than 1 year. Anti-CD19 CAR-T cell therapy is a revolutionary immunotherapy for treating relapsed or refractory (R/R) B lineage malignancies. Although there are concerns regarding CRS and CRES in central nervous system lymphoma, the use of anti-CD19 CAR-T cells to treat R/R PCNSL is safe and feasible.

Overcoming resistance to anti-CD19 CAR T-cell therapy in B-cell malignancies

Anti-CD19 chimeric antigen receptor (CAR) T-cell therapy has rapidly changed current treatment pattern, providing a better option for individuals with primary refractory or relapsed B-cell non-Hodgkin lymphoma (r/r B-NHL) and B-cell acute lymphoblastic leukemia (r/r B-ALL). However, despite the outstanding efficacy, a high relapse rate is still found in some B-cell malignancies after anti-CD19 CAR T-cell therapy, which emerges as a main barrier for improving the overall response and long-term outcomes. Understanding the resistance mechanism is crucial to improve current CAR T products, better incorporate them into the current therapy system and develop novel CAR approaches. Herein, we discuss the latest advances in understanding the mechanisms limiting efficacy of CAR T-cell therapy, resulting in CD19 negative (CD19^- ) and CD19 positive (CD19⁺ ) relapses. We also provide a whole scenario of current potential strategies to overcome these barriers.

The Autologous Hematopoietic Stem Cells Transplantation Combination-Based Chimeric Antigen Receptor T-Cell Therapy Improves Outcomes of Relapsed/Refractory Central Nervous System B-Cell Lymphoma

OBJECTIVE

The objective is to explore the effectiveness and safety of CAR T-cell therapy in advanced relapsed/refractory central nervous system B-cell lymphoma and compare the impact of autologous stem cell transplantation (ASCT) plus CAR T-cell therapy versus sequential CART therapy on the survival of patients.

METHODS

The retrospective analysis was based on the data of 17 patients with advanced relapsed/refractory central nervous system B-cell lymphoma. Bridging chemotherapy was applied before CAR T-cell infusion to further reduce the tumor burden. For patients with autologous hematopoietic stem cell successful collection, CD19/20/22CAR T-cell immunotherapy following ASCT was performed with the thiotepa-containing conditioning regimen, while sequential CD19/CD20/CD22CAR T-cell therapy was applied. For lymphodepletion, patients received bendamustine or fludarabine monotherapy or fludarabine combined with cyclophosphamide pre-CART-cell infusion.

RESULTS

Out of the 17 patients, 8 completed ASCT plus CART cell therapy, while 9 patients completed CART cell alone therapy. In efficacy assessment at 3 months after infusion, the objective response rate (ORR) was 12/17 (71%) and the complete response rate (CRR) was 11/17 (65%). The CRR of the ASCT group and non-ASCT was 100% and 44.4%, respectively (P < 0.01). The median progression-free survival was 16.3 (2.6-24.5) months, and the median overall survival was 19.3 (6-24.5) months. Patients who underwent ASCT plus CART cell therapy had significantly longer PFS (P < 0.01) and OS (P < 0.01). Grade 3 or higher immune effector cell-associated neurologic toxicity syndrome (≥grade 3 ICANS) and cytokine release syndrome (≥grade 3 CRS) events occurred in 29% and 41% of the patients, respectively. No treatment-related death occurred.

CONCLUSION

The CAR T-cell therapy could augment its efficacy in the treatment of advanced relapsed/refractory CNS B-cell lymphoma, while ASCT in combination with CART can induce durable responses and OS with a manageable side effect.

Efficacy and safety of CD19-specific CAR-T cell-based therapy in secondary central nervous system lymphoma

Encouraging response has been achieved in relapsed/refractory (R/R) B-cell lymphoma treated by chimeric antigen receptor T (CAR-T) cells. The efficacy and safety of CAR-T cells in central nervous system lymphoma (CNSL) are still elusive. Here, we retrospectively analyzed 15 patients with R/R secondary CNSL receiving CD19-specific CAR-T cell-based therapy. The patients were infused with CD19, CD19/CD20 or CD19/CD22 CAR-T cells following a conditioning regimen of cyclophosphamide and fludarabine. The overall response rate was 73.3% (11/15), including 9 (60%) with complete remission (CR) and 2 (13.3%) with partial remission (PR). During a median follow-up of 12 months, the median progression-free survival (PFS) was 4 months, and the median overall survival (OS) was 9 months. Of 12 patients with systemic tumor infiltration, 7 (58.3%) achieved CR in CNS, and 5 (41.7%) achieved CR both systemically and in CNS. Median DOR for CNS and systemic disease were 8 and 4 months, respectively. At the end point of observation, of the 7 patients achieved CNS disease CR, one was still alive with sustained CR of CNS disease and systemic disease. The other 6 died of systemic progression. Of the 15 patients, 11 (73.3%) experienced grades 1-2 CRS, and no patient had grades 3-4 CRS. Immune effector cell-associated neurotoxicity syndrome (ICANS) occurred in 3 (20%) patients, including 1 (6.6%) with grade 4 ICANS. All the CRS or ICANS were manageable. The CD19-specific CAR-T cell-based therapy appeared to be a promising therapeutic approach in secondary CNSL, based on its antitumor effects and an acceptable side effect profile, meanwhile more strategies are needed to maintain the response.

Systemic Relapse in a Young Adult Patient with Primary CNS Diffuse Large B-Cell Lymphoma

Primary central nervous system diffuse large B-cell lymphoma (PCNS-DLBCL) is a rare form of non-Hodgkin's lymphoma, characterized by an aggressive disease course. While CNS relapse is common, systemic relapse is rare with no consensus on optimal treatment. This paper presents an unusual case of advanced PCNS-DLBCL with systemic relapse, including adrenal gland involvement. A review of the existing literature and a discussion on the management of systemic relapse in PCNS-DLBCL is also provided.

Axicabtagene Ciloleucel in Patients Ineligible for ZUMA-1 Because of CNS Involvement and/or HIV: A Multicenter Experience

Secondary central nervous system lymphoma (SCNSL) is associated with poor prognosis and new therapeutic approaches are needed. The pivotal trial that led to US Food and Drug Administration (FDA) approval of axicabtagene ciloleucel excluded patients with SCNSL and human immunodeficiency virus. In this multi-institutional retrospective study, 14 SCNSL patients treated with axicabtagene ciloleucel, 3 of whom had human immunodeficiency virus, experienced rates of severe neurotoxicity and complete response of 32% and 58%, respectively. This is similar to rates observed in the pivotal ZUMA-1 trial that led to the approval of axi-cel at median follow-up of 5.9 months. Chimeric antigen receptor T-cell therapy is potentially a life-saving therapy for SCNSL patients and should not be withheld.

Advances in therapeutic strategies for primary CNS B-cell lymphomas

INTRODUCTION

Primary CNS lymphoma (PCNSL) has traditionally been treated with induction HD-MTX-based chemotherapy, followed by consolidation whole-brain radiotherapy. However, this approach is associated with significant neurocognitive complications, especially in older patients. Therefore, different consolidation protocols have been evaluated. High-dose chemotherapy followed by autologous stem cell transplantation (HD-ASCT) has the best long-term survival outcomes in younger patients.

AREAS COVERED

In this review of the literature, we focus on the overall therapeutic strategy and advances in the management of the aggressive primary CNS B-cell lymphomas.

EXPERT OPINION

In young and fit PCNSL patients, HD-ASCT is the preferred consolidation strategy to achieve long-term survivals. Older patients with good performance status should also be evaluated for MTX-based induction polychemotherapy followed by ASCT. However, management of PCNSL patients remains challenging, and new avenues with targeted therapies are under investigation. To date, ibrutinib, lenalidomide, and immune checkpoint inhibitors appearto be promising in PCNSL. However, as monotherapy, durable responses are less likely to be achieved. Unfortunately, when combined with chemoimmunotherapy, considerable toxicity and mortality have been reported. Clinical trials on these molecules are aiming to reduce toxicity and maintain responses. CAR-T-cell therapy has recently emerged as a further option. It has shown efficacy in patients with secondary CNS lymphoma, with few but encouraging results in primary CNSL.

Emerging Landscape of Immunotherapy for Primary Central Nervous System Lymphoma

Simple Summary

Primary central nervous system lymphoma (PCNSL) is characterized by its location in the central nervous system comprising the brain, the eye, the cerebrospinal fluid and the spinal cord and a poor prognosis with the current chemotherapies. Immunotherapies represent a new paradigm in the care of patients with B-cell lymphoma, but, till recently, immunotherapies studies excluded patients with PCNSL because of the lack of knowledge on the immune network in the brain. Recent studies shed a new light on the origin and characteristics of the CNS immune cells. We review the current experimental preclinical and clinical developments of immunotherapies in CNS lymphoma as well as the effects of targeted therapies on the brain microenvironment. We provide perspectives for improving the efficacy of immunotherapies in the specific setting of PCNSL for a better prognosis of this disease.

Abstract

Primary central nervous system lymphoma (PCNSL) is, mainly, a diffuse large B-cell lymphoma (DLBCL) with a non-germinal center B-cell (non-GCB) origin. It is associated with a poor prognosis and an unmet medical need. Immunotherapy has emerged as one of the most promising areas of research and is now part of the standard treatment for many solid and hematologic tumors. This new class of therapy generated great enthusiasm for the treatment of relapsed/refractory PCNSL. Here, we discuss the challenges of immunotherapy for PCNSL represented by the lymphoma cell itself and the specific immune brain microenvironment. We review the current clinical development from the anti-CD20 monoclonal antibody to CAR-T cells, as well as immune checkpoint inhibitors and targeted therapies with off-tumor effects on the brain microenvironment. Perspectives for improving the efficacy of immunotherapies and optimizing their therapeutic role in PCNSL are suggested.

Treatment of Primary CNS Lymphoma: Maximizing Clinical Benefit, Minimizing Neurotoxicity

PURPOSE OF REVIEW

The optimal treatment for newly diagnosed and refractory or relapsed primary central nervous system lymphoma (PCNSL) is not fully defined. We review the epidemiology, clinical presentation, and current management strategies for newly diagnosed PCNSL as well as emerging treatments for refractory and relapsed disease.

RECENT FINDINGS

In recent decades, the incidence of PCNSL has increased in the elderly population. With advancements in chemotherapy for PCNSL, survival has improved. However, outcomes remain inferior when compared with other forms of extranodal lymphoma. Additionally, treatments can be associated with clinically significant neurotoxicities. Despite advances in the treatment of PCNSL, current treatment regimens remain suboptimal in terms of response rates and neurotoxicity. Well-tolerated agents, especially for the elderly, are still needed.

Relapsed and refractory primary CNS lymphoma: treatment approaches in routine practice

Despite recent therapeutic progress and improved survival for many patients with primary central nervous system lymphoma (PCNSL), up to 50% of patients will experience refractory or relapsed disease following first-line treatment with high dose methotrexate (HD-MTX) based regimens. The majority of such events occur within 2 years of diagnosis although, unlike their systemic counterpart, the risk of PCNSL relapse remains, even for patients in radiologic complete response at 10 years following diagnosis. Currently, there are no approved therapies, and no widely accepted 'standard-of-care' approaches for the treatment of refractory or recurrent primary central nervous system lymphoma (rrPCNSL). Re-treatment with HD-MTX based regimens, use of non-cross resistant chemotherapy regimens, high-dose chemotherapy and autologous stem cell transplantation (HDT-ASCT), and brain irradiation all remain important therapeutic approaches for rrPCNSL. However, the survival outcomes for patients with rrPCNSL remain extremely poor and the vast majority of patients will die of their disease. Increasingly, novel treatment approaches are being investigated in early phase clinical studies. Importantly, such therapies need to be evaluated in the context of both refractory and relapsed disease; in older patients and those with co-morbid conditions; and those with neurocognitive dysfunction. A deeper understanding of the molecular genetic mechanisms underpinning rrPCNSL and its unique tumor microenvironment is urgently needed to inform biologically rational and effective therapies. rrPCNSL remains a clear unmet clinical need and a high priority area for clinical research that will require national and international collaborative studies with embedded translational science in order to improve outcomes for patients.

Sequential CD19/22 CAR T-cell immunotherapy following autologous stem cell transplantation for central nervous system lymphoma

Chimeric antigen receptor (CAR) T-cell immunotherapy following autologous stem cell transplantation (ASCT) is a promising method for refractory or relapsed multiple myeloma, but explicit data for central nervous system lymphoma (CNSL) are lacking. Here, we treated 13 CNSL patients with ASCT sequential CD19/22 CAR T-cell infusion and simultaneously evaluated the clinical efficacy and toxicity. The 13 CNSL patients analyzed included four primary CNSL and nine secondary CNSL patients. Patients 1 and 10, who had complete remission status before enrollment, maintained clinical efficacy without recurrence. Nine of the remaining 11 patients responded to our protocol with a median durable time of 14.03 months, and the overall response and complete remission rate were 81.81% and 54.55%, respectively. No patient suffered grades 3–4 cytokine-release syndrome (CRS), and only patient 10 experienced severe immune effector cell-associated neurotoxicity syndrome (ICANS). In addition, increases in serum ferritin and interleukin-6 levels were often accompanied by CRS and ICANS. After a median follow-up time of 14.20 months, the estimated 1-year progression-free survival and overall survival rates were 74.59% and 82.50%, respectively. Sequential CD19/22 CAR T-cell immunotherapy following ASCT as a novel method for CNSL appears to have encouraging long-term efficacy with relatively manageable side effects.

CAR T-Cells for CNS Lymphoma: Driving into New Terrain?

Primary CNS lymphomas (PCNSL) represent a group of extranodal non-Hodgkin lymphomas and secondary CNS lymphomas refer to secondary involvement of the neuroaxis by systemic disease. CNS lymphomas are associated with limited prognosis even after aggressive multimodal therapy. Chimeric antigen receptor (CAR) T-cells have proven as a promising therapeutic avenue in hematological B-cell malignancies including diffuse large B-cell lymphoma, B-cell acute lymphoblastic leukemia, and mantle-cell lymphoma. CARs endow an autologous T-cell population with MHC-unrestricted effectivity against tumor target antigens such as the pan B-cell marker CD19. In PCNSL, compelling and long-lasting anti-tumor effects of such therapy have been shown in murine immunocompromised models. In clinical studies on CAR T-cells for CNS lymphoma, only limited data are available and often include both patients with PCNSL but also patients with secondary CNS lymphoma. Several clinical trials on CAR T-cell therapy for primary and secondary CNS lymphoma are currently ongoing. Extrapolated from the available preliminary data, an overall acceptable safety profile with considerable anti-tumor effects might be expected. Whether these beneficial anti-tumor effects are as long-lasting as in animal models is currently in doubt; and the immunosuppressive tumor microenvironment of the brain may be among the most pivotal factors limiting efficacy of CAR T-cell therapy in CNS lymphoma. Based on an increasing understanding of CAR T-cell interactions with the tumor cells as well as the cerebral tissue, modifications of CAR design or the combination of CAR T-cell therapy with other therapeutic approaches may aid to release the full therapeutic efficiency of CAR T-cells. CAR T-cells may therefore emerge as a novel treatment strategy in primary and secondary CNS lymphoma.