PD-1 blockade with nivolumab in relapsed/refractory primary central nervous system and testicular lymphoma

Blockade of PD-1 and LAG-3 expression on CD8+ T cells promotes the tumoricidal effects of CD8+ T cells

Background

The diffuse large B-cell lymphoma (DLBCL) has the highest incidence of all lymphomas worldwide. To investigate the functions of lymphocyte activation gene 3 (LAG-3) and programmed cell death 1 (PD-1) in tissues and peripheral blood of patients with DLBCL, the expression of LAG-3 and PD-1 genes in DLBCL-TCGA were analyzed.

Methods

LAG-3 and PD-1 mRNA levels in DLBCL were analyzed using data from The Cancer Genome Atlas (TCGA) database. Utilize the Genotype-Tissue Expression (GTEx) database for assessing the variance in the expression of LAG-3, PD-1, and other associated factors between the tissues of DLBCL patients and healthy individuals. Immunohistochemistry was applied to detect the expression of LAG-3 and PD-1 levels in 137 cases of DLBCL tissues and 20 cases of reactive lymphoid hyperplasia. The prognostic value of LAG-3 and PD-1 were assessed using the Kaplan-Meier curve. The Estimation of Stromal and Immune cells in Malignant Tumor tissues using Expression data (ESTIMATE) and ssGSEA algorithm were used to explore the immune microenvironment of DLBCL. Additionally, the expression and co-expression of LAG-3 and PD-1 were detected on CD4 and CD8 T cells in peripheral blood samples from 100 cases of DLBCL tissues and 30 cases of healthy individuals using flow cytometry.

Results

According to TCGA database, LAG-3 and PD-1 gene expression levels were significantly up-regulated in DLBCL tissues. LAG-3 and PD-1 levels were also strongly positively correlated with those of most infiltrating immune cells. Overall survival of patients with high LAG-3 and PD-1 co-expression was significantly shorter than that of patients with low co-expression. In DLBCL patients, LAG-3 and PD-1 were highly expressed in peripheral blood CD8+ T cells. In addition, LAG-3 was highly expressed in CD4+ T cells, while the expression of PD-1 in CD4+ T cells of DLBCL patients showed no significant difference compared to healthy individuals. Additionally, CD8+ T cells and SU-DHL6/OCI-LY3 from patients with DLBCL were co-cultured in vitro; after addition of LAG-3 and/or PD-1 inhibitors alone, an increased perforin and granzyme B secretion levels by CD8+ T cells were detected, as well as an increase in the overall proportion of tumor cells undergoing apoptosis.

Conclusion

High LAG-3 and PD-1 levels significantly inhibit CD8+ T cell function, resulting in weakened ability to kill tumor cells. Combined LAG-3 and PD-1 blockade can restore CD8+ T cell function and provides a potential avenue for development of personalized cellular immunotherapy for DLBCL.

Immunochemotherapy or chemotherapy alone in primary central nervous system lymphoma: a National Cancer Database analysis

Debate remains over the role of rituximab, a large molecule with reduced central nervous system (CNS) penetration, in therapy for primary CNS lymphoma (PCNSL). Since 2013, the National Cancer Database has distinguished between chemotherapy and immunotherapy for frontline treatment. In this setting, rituximab would be the only standard frontline immunotherapy. We examined factors associated with the receipt of immunotherapy using a multivariate regression model for relative risk, with a random intercept to account for the hospital-specific treatment selection process. Patients were matched using a 1:1 propensity score to limit possible confounders, and overall survival (OS) was compared in the matched cohort. We identified 4691 patients with PCNSL diagnosed between 2013 and 2018. The use of immunotherapy has increased from 45% in 2013 to 76% in 2018. Immunotherapy use was associated with sociodemographic variables and local (hospital level) preference rather than clinical factors. The main factors associated with reduced use of immunotherapy included male sex, Black race or Hispanic ethnicity (compared with White non-Hispanic), HIV+ status, treatment in a lower-volume hospital, and earlier year of diagnosis. We matched 2830 patients for the survival analysis. Receipt of immunotherapy was associated with a significantly better OS (hazard ratio [HR], 0.75; 95% confidence interval [CI], 0.67-0.83). There was heterogeneity according to age, because the advantage of immunotherapy was more pronounced for patients aged ≤75 years (HR, 0.71; 95% CI, 0.63-0.80) than for those older than 75 years (HR, 0.87; 95% CI, 0.70-1.08). Overall, our findings support the current trend toward rituximab use, although a nuanced approach should be adopted when treating older patients.

Extranodal lymphoma: pathogenesis, diagnosis and treatment

Approximately 30% of lymphomas occur outside the lymph nodes, spleen, or bone marrow, and the incidence of extranodal lymphoma has been rising in the past decade. While traditional chemotherapy and radiation therapy can improve survival outcomes for certain patients, the prognosis for extranodal lymphoma patients remains unsatisfactory. Extranodal lymphomas in different anatomical sites often have distinct cellular origins, pathogenic mechanisms, and clinical manifestations, significantly influencing their diagnosis and treatment. Therefore, it is necessary to provide a comprehensive summary of the pathogenesis, diagnosis, and treatment progress of extranodal lymphoma overall and specifically for different anatomical sites. This review summarizes the current progress in the common key signaling pathways in the development of extranodal lymphomas and intervention therapy. Furthermore, it provides insights into the pathogenesis, diagnosis, and treatment strategies of common extranodal lymphomas, including gastric mucosa-associated lymphoid tissue (MALT) lymphoma, mycosis fungoides (MF), natural killer/T-cell lymphoma (nasal type, NKTCL-NT), and primary central nervous system lymphoma (PCNSL). Additionally, as PCNSL is one of the extranodal lymphomas with the worst prognosis, this review specifically summarizes prognostic indicators and discusses the challenges and opportunities related to its clinical applications. The aim of this review is to assist clinical physicians and researchers in understanding the current status of extranodal lymphomas, enabling them to make informed clinical decisions that contribute to improving patient prognosis.

Emerging entities: high-grade/large B-cell lymphoma with 11q aberration, large B-cell lymphoma with IRF4 rearrangement, and new molecular subgroups in large B-cell lymphomas. A report of the 2022 EA4HP/SH lymphoma workshop

Emerging entities and molecular subgroups in large B-cell lymphomas (LBCLs) were discussed during the 2022 European Association for Haematopathology/Society for Hematopathology workshop in Florence, Italy. This session focused on newly recognized diseases and their diagnostic challenges. High-grade/large B-cell lymphoma with 11q aberration (HG/LBCL-11q) is defined by chromosome 11q-gains and telomeric loss. FISH analysis is recommended for the diagnosis. HG/LBCL-11q can occur in the setting of immunodeficiency, including ataxia-telangiectasia, and predominates in children. The morphological spectrum of these cases is broader than previously thought with often Burkitt-like morphology and coarse apoptotic bodies. It has a Burkitt-like immunophenotype (CD10+, BCL6+, BCL2-) but MYC expression is weak or negative, lacks MYC rearrangement, and is in contrast to Burkitt lymphoma 50% of the cases express LMO2. LBCL with IRF4 rearrangement (LBCL-IRF4) occurs mainly in the pediatric population but also in adults. LBCL-IRF4 has an excellent prognosis, with distinguishing molecular findings. IRF4 rearrangements, although characteristic of this entity, are not specific and can be found in association with other chromosomal translocations in other large B-cell lymphomas. Other molecular subgroups discussed included primary bone diffuse large B-cell lymphoma (PB-DLBCL), which has distinctive clinical presentation and molecular findings, and B-acute lymphoblastic leukemia (B-ALL) with IGH::MYC translocation recently segregated from Burkitt lymphoma with TdT expression. This latter disorder has molecular features of precursor B-cells, often tetrasomy 1q and recurrent NRAS and KRAS mutations. In this report, novel findings, recommendations for diagnosis, open questions, and diagnostic challenges raised by the cases submitted to the workshop will be discussed.

Primary central nervous system lymphoma (PCNSL) in older patients

INTRODUCTION

Primary central nervous system lymphoma (PCNSL) is a rare, chemo and radio-sensitive tumor limited to the central nervous system. The incidence of PCSNL increases notably in the elderly population which represented approximately half of the patients. The limit of 'elderly' population remained debated and nonuniform, including 60 years as a cutoff for brain radiotherapy, 65 years for autologous stem-cell transplantation, and 70 years for the last clinical trials. Current therapeutic options include first line treatment based on high-dose methotrexate based polychemotherapy, consolidation chemotherapy, and adapted autologous stem cell transplantation for highly selected patients. At relapse, single agent targeted therapies or salvage chemotherapy followed by intensive consolidation are promising therapeutic options. Nevertheless, improving management of elderly patients is an urgent medical need that currently remains unresolved.

OBJECTIVE

We will focus on elderly patients with PCNSL and their specificities including clinical presentations, available therapeutic options and adaptations to be made.

CONCLUSION

To improve survival, it will be necessary to personalized and adapt the treatments, to each patient and his comorbidities, to increase their effectiveness and limit their toxicity in this frail population. Finally, inclusion of these patients in clinical trials is one of the major challenges to significantly change PCNSL elderly patient prognosis.

New hopes in relapsed refractory primary central nervous system lymphoma

PURPOSE OF REVIEW

Patients with relapsed/refractory primary central nervous system lymphoma (rrPCNSL) have poor prognosis, with a median survival after relapse of 6.8 months. In this review, we discuss the evolving landscape and the possible future directions related to this important unmet clinical need.

RECENT FINDINGS

The modern two-phase approach for newly diagnosed PCNSL based on an induction using high-dose methotrexate (HD-MTX) combinations and a subsequent consolidation, has significantly improved the outcome in this setting. However, this strategy is able to cure more or less 50% of patients. rrPCNSL patients have a very poor prognosis with a reported 5-year overall survival of 18%. Late relapses (after third year) and use of high-dose chemotherapy and autologous stem cell transplantation (HDT-ASCT) represent important factors associated with a better outcome in this setting. On the basis of the growing acquisition of knowledge on the molecular characteristics of PCNSL, the use of non-chemotherapeutic drugs such as bruton tyrosine kinase inhibitors (BTK-is), immunomodulatory drugs (IMiDs) and immune checkpoint blockers (ICBs) is increasing in the last years along with the introduction of novel approaches (CAR-T cells and blood--brain barrier disruption). However, despite high responses in some cases, durations are often short, translating in outcome results still unsatisfactory.

SUMMARY

Treatment of rrPCNSL patients is challenging. As no standard of care exist in this setting, it is of paramount importance to acquire new knowledge related to this condition and start multidisciplinary collaboration in order to improve pts outcome.

What factors are associated with the prognosis of primary testicular diffuse large B-cell lymphoma? A study based on the SEER database

PURPOSE

Primary testicular diffuse large B-cell lymphoma (PT-DLBCL) is a relatively rare urological tumor with a high degree of malignancy and a poor prognosis. This study aimed to investigate the prognostic risk factors for survival of patients with PT-DLBCL, and then to construct a predictive model and verify its reliability.

METHODS

First, we selected subjects from the SEER database (2000-2018) and analyzed the survival of PT-DLBCL patients by Kaplan-Meier test. Then, we analyzed prognostic factors by Cox regression. Finally, the data from the training cohort were used to construct a prediction model and represented with a nomogram. We evaluated the nomogram using the consistency index (C-index), decision curve analysis (DCA), and the area under the subject operating characteristic curve (ROC). In addition, calibration curves were plotted to assess the agreement between the column plot model and the actual model.

RESULTS

We identified five independent risk factors for patient prognosis affecting OS and CSS in patients with PT-DLBCL by univariate and multivariate analysis, including age, transversality, Ann Arbor staging, chemotherapy, and radiotherapy. According to the above factors, we constructed prognostic nomograms, and found that age contributed the most to the survival of patients with PT-DLBCL. The C-indexes for the nomogram of OS and CSS in the training cohort were 0.758 (0.716-0.799) and 0.763 (0.714-0.812), and in the validation cohort were OS and CSS 0.756 (0.697-0.815) and 0.748 (0.679-0.817).

CONCLUSION

We produced the first nomogram of PT-DLBCL, and it can be used to evaluate the CSS and OS of patients to determine the prognosis of patients.

Sustained response following BTK inhibitors based treatment in HIV-related primary central nervous system lymphoma: case report

BACKGROUND

Despite increasing effort for treating primary central nervous system lymphoma (PCNSL), the prognosis of human immunodeficiency virus (HIV) -related PCNSL was still unsatisfactory. There is currently a lack of clinical evidence for the application of Bruton tyrosine kinase (BTK) inhibitor in HIV-related PCNSL. We reported two HIV-related PCNSL patients, who achieved sustained remission by application of BTK inhibitor based treatment. This protocol had not been previously reported for the treatment of HIV-related PCNSL.

CASE PRESENTATION

The two cases were characterized by the treatment choice of Bruton tyrosine kinase (BTK) inhibitor. Rituximab was not recommended for them due to their very low CD4+ T cell counts. They both took MTX as the first-line therapy and got a relief in initial phase. For the first case, ibrutinib was kept both in the first-line therapy and in the maintenance therapy. When the second case underwent a progressive disease, we continued to use orelabrutinib as one of the salvage treatment, in combination with programmed cell death-1 (PD-1) inhibitor plus lenalidomide. They both achieved a continuous response of up to 20 months without opportunistic infection.

CONCLUSIONS

This report highlights the safety and effectiveness of BTK inhibitors, as well as lenalidomide and PD-1 inhibitor in HIV-related PCNSL patients. Both the new therapeutic approaches and a multidisciplinary team authentically contributed to improved survival outcome among HIV-positive PCNSL patients.

Immunotherapy in hematologic malignancies: achievements, challenges and future prospects

The immune-cell origin of hematologic malignancies provides a unique avenue for the understanding of both the mechanisms of immune responsiveness and immune escape, which has accelerated the progress of immunotherapy. Several categories of immunotherapies have been developed and are being further evaluated in clinical trials for the treatment of blood cancers, including stem cell transplantation, immune checkpoint inhibitors, antigen-targeted antibodies, antibody-drug conjugates, tumor vaccines, and adoptive cell therapies. These immunotherapies have shown the potential to induce long-term remission in refractory or relapsed patients and have led to a paradigm shift in cancer treatment with great clinical success. Different immunotherapeutic approaches have their advantages but also shortcomings that need to be addressed. To provide clinicians with timely information on these revolutionary therapeutic approaches, the comprehensive review provides historical perspectives on the applications and clinical considerations of the immunotherapy. Here, we first outline the recent advances that have been made in the understanding of the various categories of immunotherapies in the treatment of hematologic malignancies. We further discuss the specific mechanisms of action, summarize the clinical trials and outcomes of immunotherapies in hematologic malignancies, as well as the adverse effects and toxicity management and then provide novel insights into challenges and future directions.

Primary central nervous system lymphoma

Primary central nervous system lymphoma (PCNSL) is a diffuse large B cell lymphoma in which the brain, spinal cord, leptomeninges and/or eyes are exclusive sites of disease. Pathophysiology is incompletely understood, although a central role seems to comprise immunoglobulins binding to self-proteins expressed in the central nervous system (CNS) and alterations of genes involved in B cell receptor, Toll-like receptor and NF-κB signalling. Other factors such as T cells, macrophages or microglia, endothelial cells, chemokines, and interleukins, probably also have important roles. Clinical presentation varies depending on the involved regions of the CNS. Standard of care includes methotrexate-based polychemotherapy followed by age-tailored thiotepa-based conditioned autologous stem cell transplantation and, in patients unsuitable for such treatment, consolidation with whole-brain radiotherapy or single-drug maintenance. Personalized treatment, primary radiotherapy and only supportive care should be considered in unfit, frail patients. Despite available treatments, 15-25% of patients do not respond to chemotherapy and 25-50% relapse after initial response. Relapse rates are higher in older patients, although the prognosis of patients experiencing relapse is poor independent of age. Further research is needed to identify diagnostic biomarkers, treatments with higher efficacy and less neurotoxicity, strategies to improve the penetration of drugs into the CNS, and roles of other therapies such as immunotherapies and adoptive cell therapies.

Efficacy of Immune Checkpoint Blockade and Biomarkers of Response in Lymphoma: A Narrative Review

Immune checkpoint blockade (ICB) has revolutionized the prognosis of several advanced-stage solid tumors. However, its success has been far more limited in hematological malignancies and is mostly restricted to classical Hodgkin lymphoma (cHL) and primary mediastinal B cell lymphoma (PMBCL). In patients with non-Hodgkin lymphoma (NHL), response to PD-1/PD-L1 ICB monotherapy has been relatively limited, although some subtypes are more sensitive than others. Numerous predictive biomarkers have been investigated in solid malignancies, such as PD-L1 expression, tumor mutational burden (TMB) and microsatellite instability (MSI), among others. This review aims to appraise the current knowledge on PD-1/PD-L1 ICB efficacy in lymphoma when used either as monotherapy or combined with other agents, and describes potential biomarkers of response in this specific setting.

Molecular Farming of Pembrolizumab and Nivolumab

Immune checkpoint inhibitors (ICIs) are a class of immunotherapy agents capable of alleviating the immunosuppressive effects exerted by tumorigenic cells. The programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) immune checkpoint is one of the most ubiquitous checkpoints utilized by tumorigenic cells for immune evasion by inducing apoptosis and inhibiting the proliferation and cytokine production of T lymphocytes. Currently, the most frequently used ICIs targeting the PD-1/PD-L1 checkpoint include monoclonal antibodies (mAbs) pembrolizumab and nivolumab that bind to PD-1 on T lymphocytes and inhibit interaction with PD-L1 on tumorigenic cells. However, pembrolizumab and nivolumab are costly, and thus their accessibility is limited in low- and middle-income countries (LMICs). Therefore, it is essential to develop novel biomanufacturing platforms capable of reducing the cost of these two therapies. Molecular farming is one such platform utilizing plants for mAb production, and it has been demonstrated to be a rapid, low-cost, and scalable platform that can be potentially implemented in LMICs to diminish the exorbitant prices, ultimately leading to a significant reduction in cancer-related mortalities within these countries.

Management of primary and secondary CNS lymphoma

Central nervous system (CNS) lymphoma has traditionally had very poor outcomes however advances in management have seen dramatic improvements and long-term survival of patients. In primary CNS lymphoma there are now randomised trial data to inform practice, however secondary CNS lymphoma has a lack of randomised trial data and CNS prophylaxis remains a contentious area. We describe treatment strategies in these aggressive disorders. Dynamic assessment of patient fitness and frailty is key throughout treatment alongside delivery of CNS-bioavailable therapy and enrolment in clinical trials. Intensive high-dose methotrexate-containing induction followed by autologous stem cell transplantation is preferred for patients who are fit. Less intensive chemoimmunotherapy, whole brain radiotherapy and novel therapies may be reserved for patients unfit or chemoresistant. It is essential to better define patients at increased risk of CNS relapse, as well as effective prophylactic strategies to prevent it. Future prospective studies incorporating novel agents are key.

A bispecific antibody AP203 targeting PD-L1 and CD137 exerts potent antitumor activity without toxicity

BACKGROUND

Bispecific antibody has garnered considerable attention in the recent years due to its impressive preliminary efficacy in hematological malignancies. For solid tumors, however, the main hindrance is the suppressive tumor microenvironment, which effectively impedes the activation of infiltrating T cells. Herein, we designed a bispecific antibody AP203 with high binding affinity to PD-L1 and CD137 and assessed its safety and anti-tumor efficacy, as well as explored the mechanism of action.

METHODS

The optimal antibody binders against PD-L1 and CD137 were screened from the OmniMab phagemid library. The binding affinity of the constructed AP203 were evaluated using enzyme-linked immunosorbent assay (ELISA) and biolayer interferometry (BLI). T-cell stimulatory capacity was assessed using the allogeneic mixed lymphocyte reaction (MLR), antigen-specific recall response, and coculture with PD-L1-expressing cells. In vivo antitumor efficacy was evaluated using two models of tumor-xenografted humanized mice with profiling of tumor infiltrating lymphocytes (TILs). The possible toxicity of AP203 was examined using in vitro cytokine release assay by human PBMCs.

RESULTS

AP203, which simultaneously targeted PD-L1 and costimulatory CD137, elicit superior agonistic effects over parental antibodies alone or in combination in terms of T cell activation, enhanced memory recall responses, and overcoming Treg-mediated immunosuppression (P < 0.05). The agonistic activity of AP203 was further demonstrated PD-L1-dependent by coculturing T cells with PD-L1-expressing cells. In vivo animal studies using immunodeficient or immunocompetent mice both showed a dose-related antitumor efficacy superior to parental antibodies in combination (P < 0.05). Correspondingly, AP203 significantly increased tumor infiltrating CD8 + T cells, while decreased CD4 + T cells, as well as Treg cells (P < 0.05), resulting in a dose-dependent increase in the CD8 + /CD4 + ratio. Moreover, either soluble or immobilized AP203 did not induce the production of inflammatory cytokines by human PBMCs.

CONCLUSIONS

AP203 exerts potent antitumor activity not only by blocking PD-1/PD-L1 inhibitory signaling, but also by activating CD137 costimulatory signaling in effector T cells that consequently counteracts Treg-mediated immunosuppression. Based on promising preclinical results, AP203 should be a suitable candidate for clinical treatment of solid tumors.

PET/CT in Non-Hodgkin Lymphoma: An Update

Non-Hodgkin lymphomas represents a heterogeneous group of lymphoproliferative disorders characterized by different clinical courses, varying from indolent to highly aggressive. ¹⁸F-FDG-PET/CT is the current state-of-the-art diagnostic imaging, for the staging, restaging and evaluation of response to treatment in lymphomas with avidity for ¹⁸F-FDG, despite it is not routinely recommended for surveillance. PET-based response criteria (using five-point Deauville Score) are nowadays uniformly applied in FDG-avid lymphomas. In this review, a comprehensive overview of the role of ¹⁸F-FDG-PET in Non-Hodgkin lymphomas is provided, at each relevant point of patient management, particularly focusing on recent advances on diffuse large B-cell lymphoma and follicular lymphoma, with brief updates also on other histotypes (such as marginal zone, mantle cell, primary mediastinal- B cell lymphoma and T cell lymphoma). PET-derived semiquantitative factors useful for patient stratification and prognostication and emerging radiomics research are also presented.

Recent advances in the diagnosis and the treatment of primary CNS lymphoma

This review focuses on the recent progress in the management of primary central nervous system lymphoma (PCNSL). Multiomic analyses allowed to better understand the tumorigenesis of PCNSL and to establish a molecular classification with prognostic value that will optimize patient management and guide future targeted approaches. Cooperative clinical trials have demonstrated the feasibility and efficacy, in selected fit patients, of high-dose chemotherapy with autologous stem cell transplantation as post-induction consolidation, that will progressively replace whole brain radiotherapy associated with a much higher risk of delayed neurotoxicity. Several novel treatments have shown efficacy and overall good tolerance in PCNSL patients, such as Bruton's tyrosine kinase (BTK) inhibitors, imids, immune checkpoint inhibitors and chimeric antigen receptor T-cells (CAR-T). This opens promising therapeutic perspectives to improve the current standard treatment, especially for elderly and unfit patients who represent a growing population.

The Current Landscape of Immune Checkpoint Inhibitor Immunotherapy for Primary and Metastatic Brain Tumors

Antibodies against immune checkpoint inhibitors (ICIs) have revolutionized the treatment of multiple aggressive malignancies, including melanoma and non-small cell lung cancer. ICIs for the treatment of primary and metastatic brain tumors have been used with varying degrees of success. Here, we discuss the available evidence for the use of ICIs in the treatment of primary and metastatic brain tumors, highlighting challenges and opportunities for furthering this type of cancer immunotherapy in neuro-oncology.

Immune priming with avelumab and rituximab prior to R-CHOP in diffuse large B-cell lymphoma: the phase II AvR-CHOP study

Immune evasion, due to abnormal expression of programmed-death ligands 1 and 2 (PD-L1/PD-L2), predicts poor outcomes with chemoimmunotherapy in diffuse large B-cell lymphoma (DLBCL). Immune checkpoint inhibition (ICI) has limited efficacy at relapse but may sensitise relapsed lymphoma to subsequent chemotherapy. ICI delivery to immunologically intact patients may thus be the optimal use of this therapy. In the phase II AvR-CHOP study, 28 patients with treatment-naive stage II-IV DLBCL received sequential avelumab and rituximab priming ("AvRp;" avelumab 10 mg/kg and rituximab 375 mg/m2 2-weekly for 2 cycles), R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisolone for 6 cycles) and avelumab consolidation (10 mg/kg 2-weekly for 6 cycles). Grade 3/4 immune-related adverse events occurred in 11%, meeting the primary endpoint of a grade ≥3 irAE rate of <30%. R-CHOP delivery was not compromised but one patient ceased avelumab. Overall response rates (ORR) after AvRp and R-CHOP were 57% (18% CR) and 89% (all CR). High ORR to AvRp was observed in primary mediastinal B-cell lymphoma (67%; 4/6) and molecularly-defined EBV-positive DLBCL (100%; 3/3). Progression during AvRp was associated with chemorefractory disease. Two-year failure-free and overall survival were 82% and 89%. An immune priming strategy with AvRp, R-CHOP and avelumab consolidation shows acceptable toxicity with encouraging efficacy.

Survival, prognostic factors, hospitalization time and clinical performance status after first cerebral relapse or progression in 54 patients with primary CNS lymphoma not eligible for high dose chemotherapy: a retrospective analysis

BACKGROUND

Treatment of relapsed or refractory primary CNS lymphoma (r/r PCNSL) is difficult, particularly in patients not eligible for high dose chemotherapy with autologous stem cell transplantation (HDC-ASCT). No standard treatment has been defined for these patients yet.

METHODS

We retrospectively analyzed survival, prognostic factors, hospitalization time and Karnofsky performance score (KPS) before and after treatment in 54 r/r PCNSL patients with isolated cerebral relapse or progression (n = 23 refractory, n = 31 relapsed) not eligible for HDC-ASCT, who received heterogenous salvage treatments.

RESULTS

Treatments were temozolomide (+ rituximab) (n = 21), high dose methotrexate (HD-MTX)-based therapy (n = 11), whole brain radiotherapy (WBRT)/focal radiotherapy (n = 11), other systemic treatments (n = 2) and best supportive care (BSC, n = 9). Median progression free survival (PFS) and overall survival (OS) were 2.6 months (95% CI 1.0-4.2 months) and 4.8 months (95% CI 3.3-6.3 months), respectively. Eight patients survived for ≥ 3 years (13.1%, n = 3 received temozolomide, n = 3 WBRT, n = 2 HD-MTX-based treatment). Application of any salvage treatment (vs. BSC), younger age at relapse and asymptomatic (vs. symptomatic) relapse were positive prognostic factors. No significant differences in OS were found for the different salvage treatments. Median hospitalization time for treatment was 15/13 days for temozolomide (+ rituximab)/radiotherapy compared to 55 days for HD-MTX-based therapy. Median KPS in assessable patients (n = 41) was 60 (range 30-100) before treatment and 50 (range 20-90) after treatment. In patients with response to treatment (n = 16) KPS improved from 60 (range 40-90) before treatment to 70 (range 50-90) after treatment, while patients with PD (n = 25) deteriorated from 60 (range 30-100) to 40 (range 20-70).

CONCLUSION

Survival for this cohort of r/r PCNSL patients with isolated cerebral relapse or progression was poor. Considering long hospital stays associated with HD-MTX-based chemotherapy and neurotoxicity associated with WBRT, temozolomide might be worth considering with a chance of prolonged survival and avoidance of long hospitalization. Novel therapeutic agents are urgently needed to improve survival in r/r PCNSL patients.

Molecular classification and therapeutics in diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) encompasses a wide variety of disease states that have to date been subgrouped and characterized based on immunohistochemical methods, which provide limited prognostic value to clinicians and no alteration in treatment regimen. The addition of rituximab to CHOP therapy was the last leap forward in terms of treatment, but regimens currently follow a standardized course when disease becomes refractory with no individualization based on genotype. Research groups are tentatively proposing new strategies for categorizing DLBCL based on genetic abnormalities that are frequently found together to better predict disease course following dysregulation of specific pathways and to deliver targeted treatment. Novel algorithms in combination with next-generation sequencing techniques have identified between 4 and 7 subgroups of DLBCL, depending on the research team, with potentially significant and actionable genetic alterations. Various drugs aimed at pathways including BCR signaling, NF-κB dysfunction, and epigenetic regulation have shown promise in their respective groups and may show initial utility as second or third line therapies to patients with recurrent DLBCL. Implementation of subgroups will allow collection of necessary data to determine which groups are significant, which treatments may be indicated, and will provide better insight to clinicians and patients on specific disease course.

Frequent Gene Mutations and Their Possible Roles in the Pathogenesis, Treatment and Prognosis of Primary Central Nervous System Lymphoma

Primary central nervous system lymphoma (PCNSL) is a rare extranodal non-Hodgkin lymphoma with poor prognosis. In recent years, the emergence of genetic subtypes of systematic diffuse large B-cell lymphoma has highlighted the importance of molecular genetics, but large-scale research on the molecular genetics of PCNSL is lacking. Herein, we summarize the frequent gene mutations and discuss the possible pathogenesis of PCNSL. Myeloid differentiation primary response gene 88 (MYD88) and CD79B mutations, which cause abnormal activation of noncanonical nuclear factor-κB, are prominent genetic abnormalities in PCNSL. They are considered to play a major role in the pathogenesis of PCNSL. Other genes, such as caspase recruitment domain family member 11 (CARD11), tumor necrosis factor alpha induced protein 3 (TNFAIP3), transducin (β)-like 1 X-linked receptor 1, cyclin dependent kinase inhibitor 2A, PR domain zinc finger protein 1, and proviral insertion in murine malignancies 1, are also frequently mutated. Notably, the pathogenesis of immune insufficiency-associated PCNSL is related to Epstein-Barr virus infection, and its progression may be affected by different signaling pathways. The different mutational patterns in different studies highlight the heterogeneity of PCNSL. However, existing research on the molecular genetics of PCNSL is still limited, and further research into PCNSL is required to clarify the genetic characteristics of PCNSL.

Disease-Defining Molecular Features of Primary Cutaneous B-Cell Lymphomas: Implications for Classification and Treatment

Primary cutaneous B-cell lymphoma-primary cutaneous follicle center lymphoma; primary cutaneous marginal zone lymphoma; and primary cutaneous diffuse large B-cell, leg type-is a heterogeneous group with a variety of clinical and histological presentations. Until recently, the molecular bases of these disease subtypes have been unclear. We and others have identified the specific genetic characteristics that distinguish these subtypes from their respective systemic counterparts. These molecular features can improve diagnoses, determine the likelihood of concurrent or future systemic disease, and enable the rational design of novel clinical trials.

Genomic Profiling Reveals Differences in Primary Central Nervous System Lymphoma and Large B-Cell Lymphoma, With Subtyping Suggesting Sensitivity to BTK Inhibition

BACKGROUND

B-cell primary central nervous system (CNS) lymphoma (PCL) is diffuse large B-cell lymphoma (DLBCL) confined to the CNS. Less than 50% of patients with PCL achieve complete remission with current therapies. We describe the findings from comprehensive genomic profiling (CGP) of a cohort of 69 patients with PCL, 36 cases of secondary CNS lymphoma (SCL), and 969 cases of DLBCL to highlight their differences and characterize the PCL cohort. In addition, we highlight the differences in frequency of germinal center B-cell like (GCB) and non-GCB subtypes and molecular subtypes, particularly MCD and EZH subtypes, between PCL and DLBCL.

MATERIALS AND METHODS

Sixty-nine cases of B-cell PCL, 36 cases of secondary CNS lymphoma (SCL), and 969 cases of DLBCL were evaluated by CGP of 405 genes via DNAseq and 265 genes via RNAseq for fusions (FoundationOne Heme). Tumor mutational burden (TMB) was calculated from 1.23 Mb of sequenced DNA.

RESULTS

Genomic alterations with significant differences between PCL and DLBCL included MYD88, ETV6, PIM1, PRDM1, CXCR4, TP53, and CREBBP, while only MYD88 was significantly different between SCL and DLBCL. PCL cases were significantly enriched for the MCD molecular subtypes, which have an excellent response to BTKi. We report a patient with a durable complete response to BTKi consistent with their genomic profile. EBV status, CD274 amplification, and TMB status suggest that 38% of PCL patients may benefit from ICPI; however further study is warranted.

CONCLUSION

CGP of PCLs reveals biomarkers, genomic alterations, and molecular classifications predictive of BTKi efficacy and potential ICPI efficacy. Given the limitations of standard of care for PCL, CGP is critical to identify potential therapeutic approaches for patients in this rare form of lymphoma.

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.

European Association of Neuro-Oncology (EANO) guidelines for treatment of primary central nervous system lymphoma (PCNSL)

The management of primary central nervous system (PCNSL) is one of the most controversial topics in neuro-oncology because of the complexity of the disease and the limited number of controlled studies available. In 2021, given recent advances and the publication of practice-changing randomized trials, the European Association of Neuro-Oncology (EANO) created a multidisciplinary task force to update the previously published evidence-based guidelines for immunocompetent adult patients with PCNSL and added a section on immunosuppressed patients. The guideline provides consensus considerations and recommendations for the treatment of PCNSL, including intraocular manifestations and specific management of the elderly. The main changes from the previous guideline include strengthened evidence for the consolidation with ASCT in first-line treatment, prospectively assessed chemotherapy combinations for both young and elderly patients, clarification of the role of rituximab even though the data remain inconclusive, of the role of new agents, and the incorporation of immunosuppressed patients and primary ocular lymphoma. The guideline should aid the clinicians in everyday practice and decision making and serve as a basis for future research in the field.

Signaling pathways in brain tumors and therapeutic interventions

Brain tumors, although rare, contribute to distinct mortality and morbidity at all ages. Although there are few therapeutic options for brain tumors, enhanced biological understanding and unexampled innovations in targeted therapies and immunotherapies have considerably improved patients' prognoses. Nonetheless, the reduced response rates and unavoidable drug resistance of currently available treatment approaches have become a barrier to further improvement in brain tumor (glioma, meningioma, CNS germ cell tumors, and CNS lymphoma) treatment. Previous literature data revealed that several different signaling pathways are dysregulated in brain tumor. Importantly, a better understanding of targeting signaling pathways that influences malignant behavior of brain tumor cells might open the way for the development of novel targeted therapies. Thus, there is an urgent need for a more comprehensive understanding of the pathogenesis of these brain tumors, which might result in greater progress in therapeutic approaches. This paper began with a brief description of the epidemiology, incidence, risk factors, as well as survival of brain tumors. Next, the major signaling pathways underlying these brain tumors' pathogenesis and current progress in therapies, including clinical trials, targeted therapies, immunotherapies, and system therapies, have been systemically reviewed and discussed. Finally, future perspective and challenges of development of novel therapeutic strategies in brain tumor were emphasized.

Primary CNS lymphoma: update on molecular pathogenesis and therapy

Primary central nervous system lymphoma (PCNSL) is a rare and aggressive form of extra-nodal non-Hodgkin lymphoma that as a brain tumor poses a unique set of challenges in diagnosis and management. With the advent of next-generation sequencing, we review updates in the understanding of its molecular and genomic pathogenesis. We also highlight key issues in management, with a focus on emerging technologies and new biological therapies including monoclonal antibodies, IMiDs, BTK inhibitors, PD-1 inhibitors, and CAR-T therapy. Integration of these approaches will likely enhance induction and consolidation strategies to suppress NF-κB activation and the anti-tumor immune response, while minimizing the often noxious effects of genotoxic approaches.

Resistance mechanisms of immune checkpoint inhibition in lymphoma: Focusing on the tumor microenvironment

Immune checkpoint inhibitors (ICIs) have revolutionized the therapeutic strategies of multiple types of malignancies including lymphoma. However, efficiency of ICIs varies dramatically among different lymphoma subtypes, and durable response can only be achieved in a minority of patients, thus requiring unveiling the underlying mechanisms of ICI resistance to optimize the individualized regimens and improve the treatment outcomes. Recently, accumulating evidence has identified potential prognostic factors for ICI therapy, including tumor mutation burden and tumor microenvironment (TME). Given the distinction between solid tumors and hematological malignancies in terms of TME, we here review the clinical updates of ICIs for lymphoma, and focus on the underlying mechanisms for resistance induced by TME, which play important roles in lymphoma and remarkably influence its sensitivity to ICIs. Particularly, we highlight the value of multiple cell populations (e.g., tumor infiltrating lymphocytes, M2 tumor-associated macrophages, and myeloid-derived suppressor cells) and metabolites (e.g., indoleamine 2, 3-dioxygenase and adenosine) in the TME as prognostic biomarkers for ICI response, and also underline additional potential targets in immunotherapy, such as EZH2, LAG-3, TIM-3, adenosine, and PI3Kδ/γ.

Diffuse large B-cell lymphomas, not otherwise specified, and emerging entities

Diffuse large B-cell lymphoma (DLBCL) is an aggressive and heterogenous group of diseases and the most common subtype of non-Hodgkin lymphoma. In the past decade, there has been an explosion in molecular profiling that has helped to identify subgroups and shared oncogenic driving mechanisms. Since the 2017 World Health Organization (WHO) classification, additional studies investigating these genomic abnormalities and phenotypic findings have been reported. Here we review these findings in DLBCL and address the proposed changes by the 2022 International Consensus Classification.

Five-gene signature for the prediction of response to immune checkpoint inhibitors in patients with gastric and urothelial carcinomas

BACKGROUND

Ample evidence supports the potential of programmed death-ligand 1 (PD-L1) expression, detected by immunohistochemistry, as a predictive biomarker for immunotherapy in patients with advanced cancers. To predict the response to immune checkpoint inhibitors in patients with gastric and urothelial carcinomas, we aimed to replace PD-L1 combined positive score (CPS) with CD274 mRNA in the original four-gene signature and PD-L1 CPS model developed by us.

METHOD

We used quantitative real-time polymerase chain reaction (qRT-PCR) to measure the expression levels of five target genes in a cohort of 49 patients (33 with gastric cancer and 16 with urothelial carcinoma) who had received immunotherapy and whose therapeutic responses were available. The predictive performance was evaluated using R package maxstat.

RESULTS

Cutoff values of mRNA expression level were measured using the log-rank statistics for progression-free survival (PFS). Based on these cutoffs, immunotherapy responses were predicted and sorted into responder (n = 12, 24.5%) and non-responder (n = 37, 75.5%) groups. The median PFS values of predicted responders and non-responders were 14.8 months (95% confidence interval [CI]: 0-34.7) and 4.7 months (95% CI: 1.0-8.4, p = 0.02), respectively. Among the 12 predicted responders, 10 had microsatellite-stable tumors with a low tumor mutational burden. The actual clinical responses (complete and partial) were higher in the responder group than those in the non-responder group: 83.3% and 16.2%, respectively.

CONCLUSION

We modified a predictive biomarker for CD274 mRNA expression to predict the response to immunotherapy in patients with gastric or urothelial carcinomas.

Insights and Strategies of Melanoma Immunotherapy: Predictive Biomarkers of Response and Resistance and Strategies to Improve Response Rates

Despite the recent successes and durable responses with immune checkpoint inhibitors (ICI), many cancer patients, including those with melanoma, do not derive long-term benefits from ICI therapies. The lack of predictive biomarkers to stratify patients to targeted treatments has been the driver of primary treatment failure and represents an unmet medical need in melanoma and other cancers. Understanding genomic correlations with response and resistance to ICI will enhance cancer patients' benefits. Building on insights into interplay with the complex tumor microenvironment (TME), the ultimate goal should be assessing how the tumor 'instructs' the local immune system to create its privileged niche with a focus on genomic reprogramming within the TME. It is hypothesized that this genomic reprogramming determines the response to ICI. Furthermore, emerging genomic signatures of ICI response, including those related to neoantigens, antigen presentation, DNA repair, and oncogenic pathways, are gaining momentum. In addition, emerging data suggest a role for checkpoint regulators, T cell functionality, chromatin modifiers, and copy-number alterations in mediating the selective response to ICI. As such, efforts to contextualize genomic correlations with response into a more insightful understanding of tumor immune biology will help the development of novel biomarkers and therapeutic strategies to overcome ICI resistance.

BTK inhibitor combined with anti-PD-1 monoclonal antibody for the treatment of CD20-negative primary central nervous system lymphoma: A case report

CD20-negative diffuse large B-cell lymphoma (DLBCL) is a rare type of lymphoproliferative disorder characterized by a high degree of aggressiveness, a tendency for extranodal invasion and chemotherapeutic resistance. CD20-negative DLBCL originating from the nervous system is rarer. In primary central nervous system lymphoma (PCNSL), >90% of cases are histologically classified as DLBCL. The present study reports the case of a 65-year-old female with CD20-negative PCNSL, whose primary clinical symptom was a persistent headache. Serum tests for human immunodeficiency virus, Epstein-Barr virus-DNA, human herpesvirus 8, hepatitis B and hepatitis C were negative. Cranial magnetic resonance imaging suggested multiple intracranial occupancies. The neoplastic cells were found to be positive for CD19, CD79α, Bcl-2 (~92%) and c-Myc (~50%), while showing negative results for CD20, CD138, programmed cell death protein 1 (PD-1) and programmed cell death receptor 1 ligand 1 (PD-L1). The Ki-67 proliferation index was >80%. In the tumor microenvironment, <10% of the tumor-associated macrophages expressed PD-L1. The number of PD-1-positive tumor-infiltrating lymphocytes was 30-40 cells according to high-power field microscopy. The patient's disease progressed during methotrexate-based treatment, leading to a change in the treatment regimen to the Bruton tyrosine kinase inhibitor, zanubrutinib, combined with the anti-PD-1 monoclonal antibody tislelizumab. After two courses of the combined treatment, the patient achieved complete remission (CR) and continued to receive consolidation treatment. In the 20 months of follow-up since CR was achieved, the patient's general condition was good and the disease was in continuous remission. The present case report and literature review show that a combination of drugs targeting different mechanisms may be used to treat PCNSL to prolong patient survival time. The mechanism of the enhanced efficacy of a combination of the two drugs may be related to the enhancement of antitumor T-cell immune responses and reversal of T-cell immune metabolic dysfunctions by the inhibition of glycolysis.

Rituximab with high-dose methotrexate is effective and cost-effective in newly diagnosed primary central nervous system lymphoma

Induction chemotherapy based on high-dose methotrexate is considered as the standard approach for newly diagnosed primary central nervous system lymphomas (PCNSLs). However, the best combination chemotherapeutic regimen remains unclear. This study aimed to determine the efficacy and toxicities of rituximab with methotrexate (R-M regimen). Consecutive 37 Chinese patients receiving R-M regimen as induction chemotherapy were retrospectively identified from January 2015 to June 2020 from our center in eastern China. Fourteen patients receiving rituximab plus methotrexate with cytarabine (R-MA regimen) at the same period were identified as the positive control group. The response rates, survival, toxicities, length of hospital stay (LOS), and cost were compared. Compared with the R-MA regimen, the R-M regimen showed comparable response rate and survival outcomes, but had fewer grade 3-4 hematological toxicities, shorter LOS, lower mean total hospitalization cost and lower mean total antibiotic cost. Complete remission at the end of induction chemotherapy and ECOG > 3 were independent prognostic factors for overall survival. In conclusion, R-M regimen is an effective and cost-effective combination treatment for PCNSLs, which warrants further evaluation in randomized trials.

Cerebrospinal fluid soluble programmed death‐ligand 1 is a useful prognostic biomarker in primary central nervous system lymphoma

The increased expression of programmed death-ligands 1 and 2 (PD-L1 and PD-L2, respectively) on tumour cells contributes to immune evasion, suggesting that these proteins are attractive therapeutic targets. This study aimed to evaluate the validity of cerebrospinal fluid (CSF) soluble PD-L1 (sPD-L1) and soluble PD-L2 (sPD-L2) as biomarkers for primary central nervous system lymphoma (PCNSL). We determined the CSF concentrations of sPD-L1 and sPD-L2 in 46 patients with PCNSL using enzyme-linked immunosorbent assays (ELISAs). A control group comprised 153 patients with other brain tumours, inflammatory/infectious status, or neurodegenerative diseases. Only CSF sPD-L1 levels were significantly higher in patients with PCNSL relative to the controls. CSF sPD-L1 also exhibited superior overall discrimination performance compared to CSF sPD-L2 in diagnosing PCNSL. Compared with patients with PCNSL with low CSF sPD-L1 levels, more patients with high levels had high serum lactate dehydrogenase levels, leptomeningeal involvement, and deep-brain involvement. Furthermore, CSF sPD-L1 could predict poor survival in PCNSL but CSF sPD-L2 could not. Intriguingly, CSF sPD-L1 levels were correlated with disease status and their dynamic changes post treatment could predict time to relapse. In conclusion, this study identified CSF sPD-L1 as a promising prognostic biomarker, indicating a therapeutic potential of PD-L1 blockade in PCNSL.

Primary extranodal diffuse large B-cell lymphoma in the rituximab era: a single center, retrospective analysis

OBJECTIVES

To analyse the clinical characteristics and therapeutic response of Chinese patients with primary extranodal diffuse large B-cell lymphoma DLBCL (PE-DLBCL).

METHODS

We analysed the clinical features and outcomes of 197 patients who were newly diagnosed with PE-DLBCL between January 2015 and December 2020.

RESULTS

The gastrointestinal tract showed the highest rate of involvement (34%), followed by the central nervous system (CNS) and intraocular system (31.5%). The 3-year overall survival (OS) rate was 81% for the entire group and 79% for those with CNS and vitreoretinal involvement. Ann Arbour stage, lactate dehydrogenase level, International Prognostic Index > 2, and complete remission (CR) were significantly related to the survival of patients with PE-DLBCL. The lack of CR was the only independent adverse prognostic factor for OS.

CONCLUSION

The clinical outcomes of patients with PE-DLBCL at our centre were encouraging, especially for patients with CNS and vitreoretinal involvement.

Bruton's tyrosine kinase inhibitors in the treatment of primary central nervous system lymphoma: A mini-review

Primary central nervous system lymphoma (PCNSL) is a highly aggressive brain tumor with poor prognosis if no treatment. The activation of the NF-κB (nuclear factor kappa-B) is the oncogenic hallmark of PCNSL, and it was driven by B cell receptor (BCR) and Toll-like receptor (TLR) signaling pathways. The emergence of Bruton's tyrosine kinase inhibitors (BTKis) has brought the dawn of life to patients with PCNSL. This review summarizes the management of PCNSL with BTKis and potential molecular mechanisms of BTKi in the treatment of PCNSL. And the review will focus on the clinical applications of BTKi in the treatment of PCNSL including the efficacy and adverse events, the clinical trials currently being carried out, the underlying mechanisms of resistance to BTKi and possible solutions to drug resistance.

Primary CNS Lymphoma: Progress With Dose-Intensive Consolidation

The Oncology Grand Rounds series is designed to place original reports published in the Journal into clinical context. A case presentation is followed by a description of diagnostic and management challenges, a review of the relevant literature, and a summary of the authors' suggested management approaches. The goal of this series is to help readers better understand how to apply the results of key studies, including those published in Journal of Clinical Oncology, to patients seen in their own clinical practice.

Treatment Options for Recurrent Primary CNS Lymphoma

OPINION STATEMENT

Primary CNS lymphoma (PCNSL) constitutes a rare extranodal variant of non-Hodgkin lymphoma (NHL) with an annual incidence of 0.45/100,000. Given the paucity of large prospective clinical trials, there is no consensus treatment for refractory or relapsed (r/r) PCNSL, and available strategies are largely based on retrospective analyses. Patient age, performance status, previously administered treatment, duration of response, and molecular characteristics guide selection of salvage therapy. Patients with a good performance status (KPS >70), particularly ≤65 years, and adequate organ function should be considered for salvage polychemotherapy. Based on its high overall response rate even in the relapsed setting, we choose high-dose (≥ 3.5g/m²) methotrexate (HD-MTX) based regimens, e.g., R-MPV (rituximab, HD-MTX, procarbazine, and vincristine), for remission re-induction as long as patients were sensitive to first line HD-MTX-based regimens, especially when duration of previous response was ≥ 1 year. Following successful remission induction, we choose myeloablative chemotherapy (e.g., thiotepa, busulfan, cyclophosphamide) and subsequent autologous stem cell transplant in curative intent whenever feasible. Alternatively, conventional chemotherapy regimens (for example, monthly HD-MTX) or low-dose whole-brain radiation therapy (WBRT) are selected for consolidation in non-transplant candidates in complete remission. In cases of HD-MTX refractory disease or contraindications, we use pemetrexed; temozolomide/rituximab; high-dose cytarabine; or whole brain radiation for remission induction. Clinical trial participation is considered as well. Emerging therapies for upfront or salvage therapy under ongoing investigation include bruton tyrosine kinase inhibition (e.g., ibrutinib), immunomodulatory drugs (e.g., lenalidomide), immune checkpoint inhibitors (ICI, e.g., nivolumab), and chimeric antigen receptor T (CAR-T) cell therapy.

Mutation profile of diffuse large B-cell lymphoma with relapses in the central nervous system

Introduction. The recurrence of diffuse large B-cell cell lymphoma in the central nervous system in the vast majority of cases is a fatal manifestation of the disease. The study of the lymphoma mutational profile can improve the accuracy of the prognosis of relapse in the central nervous system and justify the selection of patients for preventive treatment. Aim. To evaluate the mutational profile of cases of diffuse large B-cell cell lymphoma with central nervous system damage in relapse based on the results of our own experiment on high-performance sequencing.

Materials and methods. On the Illumina platform, full-exome sequencing of diagnostic samples of diffuse large B-cell cell lymphoma with relapses in the central nervous system was performed. A panel including more than 70 genes was analyzed.

Results. Four main groups of genetic events can be distinguished in the group of studied samples, namely: combined mutations in the NF-kB (MYD88, NOTCH1, CD79B, CARD11) and JAK-STAT (PIM1, STAT6) signaling pathways, as well as aberrations in the main oncosuppressor TP53 and chromatin remodeling system genes (ARID1A, KMT2D, EP300, SMARCA4). A recurrent mutation c. 794T>C, p.L265P MYD88 was detected in the study group. Among other findings, mutations in the CIITA and CD58 genes should be noted, which are important in avoiding tumor cells from immune surveillance.

Conclusion. Despite the apparent heterogeneity of the mutational profile of diffuse large B-cell cell lymphoma with relapses in the central nervous system, in most cases, tumor cells were characterized by genetic disorders leading to the production of a large number of pro-inflammatory cytokines by malignant lymphocytes, as well as aberrations that reduce immunogenicity and contribute to the avoidance of immune surveillance by the tumor.

SOHO State of the Art Updates and Next Questions: Prophylaxis and Management of Secondary CNS Lymphoma

Secondary CNS lymphoma (SCNSL) is a rare but frequently fatal complication of systemic lymphoma. There is no standard treatment for SCNSL, and patients who develop SCNSL at diagnosis or after frontline therapy often receive highly intensive chemotherapy regimens that are inactive against primary chemorefractory disease and too toxic for older, frail patients to tolerate. Because the prognosis of SCNSL is so poor, management has historically emphasized prevention, but the current methods of CNS prophylaxis are not universally effective. To improve both the prevention and management of SCNSL, better characterization of the molecular determinants of CNS invasion is needed. Novel treatments that are currently being studied in SCNSL include targeted pathway inhibitors and cellular therapy, but SCNSL patients are often excluded from clinical trials of promising new therapies.

Intratumor heterogeneity and T cell exhaustion in primary CNS lymphoma

BACKGROUND

Primary central nervous system lymphoma (PCNSL) is a rare lymphoma of the central nervous system, usually of diffuse large B cell phenotype. Stereotactic biopsy followed by histopathology is the diagnostic standard. However, limited material is available from CNS biopsies, thus impeding an in-depth characterization of PCNSL.

METHODS

We performed flow cytometry, single-cell RNA sequencing, and B cell receptor sequencing of PCNSL cells released from biopsy material, blood, and cerebrospinal fluid (CSF), and spatial transcriptomics of biopsy samples.

RESULTS

PCNSL-released cells were predominantly activated CD19+CD20+CD38+CD27+ B cells. In single-cell RNA sequencing, PCNSL cells were transcriptionally heterogeneous, forming multiple malignant B cell clusters. Hyperexpanded B cell clones were shared between biopsy- and CSF- but not blood-derived cells. T cells in the tumor microenvironment upregulated immune checkpoint molecules, thereby recognizing immune evasion signals from PCNSL cells. Spatial transcriptomics revealed heterogeneous spatial organization of malignant B cell clusters, mirroring their transcriptional heterogeneity across patients, and pronounced expression of T cell exhaustion markers, co-localizing with a highly malignant B cell cluster.

CONCLUSIONS

Malignant B cells in PCNSL show transcriptional and spatial intratumor heterogeneity. T cell exhaustion is frequent in the PCNSL microenvironment, co-localizes with malignant cells, and highlights the potential of personalized treatments.

Investigation of the efficacy and safety of cryoablation and intra-arterial PD-1 inhibitor in patients with advanced disease not responding to checkpoint inhibitors: An exploratory study

Objective

To explore the effectiveness of cryoablation combined with arterial perfusion with programmed cell death protein 1 inhibitors in overcoming immune resistance in advanced solid cancers.

Methods

In this pilot retrospective study, nine patients with solid cancers were treated with tumour cryoablation and arterial perfusion with programmed cell death protein 1 inhibitors, which had previously proven ineffective. The CIBERSORT software was used to estimate the levels of tumour-infiltrating immune cells in the challenged tumour. Changes in the levels of circulating T cells were assessed using flow cytometry. The primary endpoints were disease control and objective response rates, and the secondary endpoint was safety.

Results

The nine patients with advanced solid tumours received cryoablation combined with arterial perfusion with programmed cell death protein 1 inhibitors between June and December 2021. The median follow-up time was 5.8 months. We recorded an objective response rate in two patients (22.22%). The best overall responses were partial responses in two patients (22.22%) and one case (11.11%) of stable disease, while six patients (66.67%) presented progressive disease. However, the median overall survival time was not reached. The median progression-free survival was 2.4 months. Treatment-related severe adverse events included one case of abdominal infection and one case of upper gastrointestinal bleeding, which were cured after the intervention. The CIBERSORT software confirmed the importance of cryoablation in regulating tumour-infiltrating immune cells. Thus, macrophage polarisation from the M2 to the M1 phenotype in the challenged tumour and a gradual increase in the levels of circulating CD4⁺ T cells were observed after administration of the combination therapy.

Conclusion

Cryoablation combined with arterial perfusion with programmed cell death protein 1 inhibitors has the potential efficacy and safety to overcome immune resistance in patients with advanced solid cancers. The combination therapy leads to macrophage polarisation from the M2 to the M1 phenotype in the challenged tumour to enhance antitumour immunity.

Primary central nervous system lymphoma

Primary central nervous system lymphoma (PCNSL) is a rare extranodal lymphomatous malignancy that affects the brain, spinal cord, leptomeninges, or vitreoretinal space, without evidence of systemic involvement. The diagnosis of PCNSL requires a high level of suspicion because clinical presentation varies depending upon involved structures. Initiation of treatment is time sensitive for optimal neurologic recovery and disease control. In general, the prognosis of PCNSL has improved significantly over the past few decades, largely as a result of the introduction and widespread use of high-dose methotrexate (MTX) chemotherapy, which is considered the backbone of first-line polychemotherapy treatment. Upon completion of MTX-based treatment, a consolidation strategy is often required to prolong duration of response. Consolidation can consist of radiation, maintenance therapy, nonmyeloablative chemotherapy, or myeloablative treatment followed by autologous stem cell transplant. Unfortunately, even with consolidation, relapse is common, and 5-year survival rates stand at only 30% to 40%. Novel insights into the pathophysiology of PCNSL have identified key mechanisms in tumor pathogenesis, including activation of the B-cell receptor pathway, immune evasion, and a suppressed tumor immune microenvironment. These insights have led to the identification of novel small molecules targeting these aberrant pathways. The Bruton tyrosine kinase inhibitor ibrutinib and immunomodulatory drugs (lenalidomide or pomalidomide) have shown promising clinical response rates for relapsed/refractory PCNSL and are increasingly used for the treatment of recurrent disease. This review provides a discussion of the clinical presentation of PCNSL, the approach to work-up and staging, and an overview of recent advancements in the understanding of the pathophysiology and current treatment strategies for immunocompetent patients.

Pemetrexed Plus Lenalidomide for Relapsed/Refractory Primary Central Nervous System Lymphoma: A Prospective Single-Arm Phase II Study

The prognosis of relapsed/refractory (R/R) primary central nervous system lymphoma (PCNSL) is dismal, and there are limited treatment options for these patients. This was a prospective single-arm phase II study of combined pemetrexed and lenalidomide for salvage treatment of R/R PCNSL. Patients with R/R PCNSL (n = 38) who had undergone two or more different therapeutic regimens and experienced disease progression or recurrence were enrolled. The primary endpoint was overall response rate (ORR). Secondary endpoints were progression-free survival (PFS) and overall survival (OS). Patients were followed up for a median of 18 (range, 1–36) months. ORR was 68.4%, with median PFS and OS of 6 and 18 months, respectively. Adverse events (AEs) included myelosuppression, fatigue, nausea, fever, infection, cardiac disease, and thrombogenesis. Commonly observed grade ≥ 3 AEs included neutropenia (5.3%), leukopenia (2.6%), thrombocytopenia (7.9%), and infection (2.6%). Elevated lactate dehydrogenase (LDH) levels (χ2 = 13.25; P = 0.0003) and bulky disease (P = 0.032; χ2 = 4.580) were associated with short PFS. Elevated serum LDH level (P = 0.011; χ2 = 6.560), abnormal lymphoma cells in the cerebrospinal fluid (CSF) [P = 0.011; χ2 = 6.445], and multiple lesions (P = 0.036; χ2 = 4.404) were significantly associated with poorer OS. Abnormal lymphoma cells in the CSF were an independent predictor of poor prognosis on multivariate analysis (P = 0.034; hazard ratio (HR) = 2.836; 95% confidence interval, 1.082–7.434). Our results indicate that pemetrexed plus lenalidomide is effective for heavily treated R/R PCNSL, with moderate toxicity. Trial registration: #ChiCTR1900028070.

Successful Consolidation/Maintenance Therapy with Single Agent Ibrutinib for Primary CNS Lymphoma after Initial Induction Therapy

Primary central nervous system lymphoma (PCNSL) is a rare and aggressive disease that originates from lymphocytes and develops in the central nervous system. There is no standard consolidation/maintenance therapy for PCNSL. While there exists a variety of options, the high chance of inferior outcomes for elderly patients and the risk of neurotoxicity requires exploration of alternative options for consolidation/maintenance therapy for PCNSL in the elderly population with CNS lymphoma. We treated one 77-year-old patient with single agent ibrutinib, a Bruton’s tyrosine kinase inhibitor that crosses the blood-brain-barrier, as consolidation/maintenance therapy after induction therapy with high-dose methotrexate (HD-MTX) and rituximab plus temozolomide. This treatment resulted in good tolerance, further resolution of a small residue lymphoma, and sustained remission. The patient has completed one year of consolidation/maintenance therapy and is currently under clinical and imaging surveillance. She has survived 27 months without recurrence since diagnosis. This case shows the potential effectiveness of single agent ibrutinib as consolidation/maintenance therapy for PCNSL after induction therapy. More cases are needed to confirm the findings.

CNS Lymphoma: Clinical Pearls and Management Considerations

Primary CNS lymphoma presents unique challenges for the clinician. New evidence has emerged regarding the appropriate workup, management considerations, and treatment. In this paper, we highlight the clinical presentations, disease prognosis, and management considerations. We place specific emphasis on the decision tree for immunocompetent and immunocompromised. The key imaging characteristics are discussed. Once biopsy prove lymphoma, important management considerations are addressed. We highlight need for follow up and role for surgery verse radiation. Finally, we present emerging treatment options and pre-clinical work that will be making its way through the pipeline. This up-to-date review will serve as a key learning tool for clinicians and researchers.

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.

Hodgkin Lymphoma: Biology and Differential Diagnostic Problem

Hodgkin lymphomas (HLs) are lymphoid neoplasms that are morphologically defined as being composed of dysplastic cells, namely, Hodgkin and Reed–Sternberg cells, in a reactive inflammatory background. The biological nature of HLs has long been unclear; however, our understanding of HL-related genetics and tumor microenvironment interactions is rapidly expanding. For example, cell surface overexpression of programmed cell death 1 ligand 1 (CD274/PD-L1) is now considered a defining feature of an HL subset, and targeting such immune checkpoint molecules is a promising therapeutic option. Still, HLs comprise multiple disease subtypes, and some HL features may overlap with its morphological mimics, posing challenging diagnostic and therapeutic problems. In this review, we summarize the recent advances in understanding the biology of HLs, and discuss approaches to differentiating HL and its mimics.