A functional mammalian display screen identifies rare antibodies that stimulate NK cell-mediated cytotoxicity.

Therapies that boost the antitumor immune response have shown a great deal of success. Although most of these therapies have focused on enhancing T cell functions, there is a growing interest in developing therapies that can target other immune cell subsets. Like T cells, natural killer (NK) cells are cytotoxic effector cells that play a key role in the antitumor response. To advance the development of NK-based therapies, we developed a functional screen to rapidly identify antibodies that can activate NK cells. We displayed antibodies on a mammalian target cell line and probed their ability to stimulate NK cell-mediated cytotoxicity. From this screen, we identified five antibodies that bound with high affinity to NK cells and stimulated NK cell-mediated cytotoxicity and interferon-γ (IFN-γ) secretion. We demonstrate that these antibodies can be further developed into bispecific antibodies to redirect NK cell-mediated cytotoxicity toward CD20+ B cell lymphoma cells and HER2+ breast cancer cells. While antibodies to two of the receptors, CD16 and NCR1, have previously been targeted as bispecific antibodies to redirect NK cell-mediated cytotoxicity, we demonstrate that bispecific antibodies targeting NCR3 can also potently activate NK cells. These results show that this screen can be used to directly identify antibodies that can enhance antitumor immune responses.

Older patients with primary central nervous system lymphoma: Survival and prognostication across 20 U.S. cancer centers.

There is a paucity of large-scale data delineating outcomes and prognostication of older patients with primary central nervous system lymphoma (PCNSL). We retrospectively analyzed 539 newly-diagnosed PCNSL patients ages ≥60 years across 20 U.S. academic centers. The median age was 70 years (range 60-88); at least one geriatric syndrome was present in 46%; the median Cumulative Index Ratings Scale-Geriatrics (CIRS-G) score was 6 (range, 0-27); and 36% had impairment in activities of daily living (ADL). The most common induction regimens were high-dose methotrexate (HD-MTX) ± rituximab; methotrexate, temozolomide, rituximab (MTR); and rituximab, methotrexate, procarbazine, vincristine (R-MPV). Overall, 70% of patients achieved remission, with 14% undergoing consolidative autologous stem cell transplant (ASCT) and 24% receiving maintenance. With 58-month median follow-up, median progression-free survival (PFS) and overall survival (OS) were 17 months (95% CI 13-22 months) and 43 months (95% CI 31-56 months), respectively. Three-year PFS and OS were highest with MTR (55% and 74%, respectively). With single-agent methotrexate ± rituximab, 3-year PFS and OS were 30% (p = .0002) and 47% (p = .0072). On multivariate analysis, increasing age at diagnosis and Cooperative Oncology Group (ECOG) performance status (PS) was associated with inferior PFS; age, hypoalbuminemia, higher CIRS-G score, and ECOG PS adversely affected OS. Among patients receiving maintenance, 3-year PFS was 65% versus 45% without maintenance (p = 0.02), with 3-year OS of 84% versus 61%, respectively (p = .0003). Altogether, outcomes in older PCNSL patients appeared optimized with HD-MTX combination induction regimens and maintenance therapy. Furthermore, several prognostic factors, including geriatric measures, were associated with inferior outcomes.

Blood Coagulation Factor Fibrinogen in Tumor Pathogenesis of Central Nervous System B-Cell Lymphoma.

Central nervous system (CNS) lymphoma is an extranodal non-Hodgkin B-cell lymphoma characterized by malignant lymph tissue arising in the brain or spinal cord, associated with inflammation and blood-brain barrier (BBB) disruption. Although BBB disruption is known to occur in patients with CNS lymphoma, a direct link between these two has not been shown. Herein, abundant deposition of the blood coagulation protein fibrinogen around B-cell lymphoma was detected in CNS lymphoma patients and in the CNS parenchyma in an orthotopic mouse model. Functional enrichment analysis of unbiased cerebrospinal fluid proteomics of CNS B-cell lymphoma patients showed that coagulation protein networks were highly connected with tumor-associated biological signaling pathways. In vivo two-photon imaging demonstrated that lymphoma growth was associated with BBB disruption, and in vitro experiments identified a role for fibrinogen in promoting lymphoma cell adhesion. Overall, these results identify perivascular lymphoma clustering at sites of fibrinogen deposition, and suggest that fibrinogen may be a target for pharmacologic intervention in metastatic B-cell lymphoma associated with BBB disruption.

On point in primary CNS lymphoma.

Primary CNS lymphoma (PCNSL) is an aggressive brain tumor that represents a significant challenge both to elucidate its biological pathogenesis as well as to develop definitive precision medicines with minimal collateral toxicity. We highlight the key issues in diagnosis and treatment and focus on emerging technologies, current options among consolidation strategies, and biological agents. We anticipate that further development of molecular diagnostics and molecular imaging approaches that elucidate minimal residual disease in brain parenchyma, leptomeninges, intraocular compartments and even bone marrow will greatly impact the delivery and timing of cytotoxic and biological therapies. Implementation of these approaches is likely essential to clarify ongoing discrepancies in the interpretation of clinical trial results that currently are based on relatively unrefined definitions of response. While the results of early phase investigations involving ibrutinib and the IMiD agents, lenalidomide, pomalidomide, as well as avadomide, strongly support the hypothesis that the B-cell receptor (BCR) pathway, involving MYD88 and CD79B and NF-kB activation, is critical to the pathogenesis of PCNSL, much work is needed to elucidate mechanisms of resistance. Similarly, development of strategies to overcome immunosuppressive mechanisms that are upregulated in the tumor microenvironment is a high priority. Finally, ongoing evidence supports the hypothesis that the blood-brain barrier represents a significant impediment to efficient brain tumor penetration of novel therapeutic agents and innovative strategies of drug delivery remain essential to further improve outcomes.

How I treat CNS lymphomas.

The pathogenesis of primary and secondary central nervous system (CNS) lymphoma poses a unique set of diagnostic, prognostic, and therapeutic challenges. During the past 10 years, there has been significant progress in the elucidation of the molecular properties of CNS lymphomas and their microenvironment, as well as evolution in the development of novel treatment strategies. Although a CNS lymphoma diagnosis was once assumed to be uniformly associated with a dismal prognosis, it is now reasonable to anticipate long-term survival, and possibly a cure, for a significant fraction of CNS lymphoma patients. The pathogenesis of CNS lymphomas affects multiple compartments within the neuroaxis, and proper treatment of the CNS lymphoma patient requires a multidisciplinary team with expertise not only in hematology/oncology but also in neurology, neuroradiology, neurosurgery, clinical neuropsychology, ophthalmology, pathology, and radiation oncology. Given the evolving principles of management and the evidence for improvements in survival, our goal is to provide an overview of current knowledge regarding the pathogenesis of CNS lymphomas and to highlight promising strategies that we believe to be most effective in establishing diagnosis, staging, and therapeutic management.

Multicenter phase 1 trial of intraventricular immunochemotherapy in recurrent CNS lymphoma.

UNLABELLED: Recurrent CNS lymphoma continues to be associated with poor outcomes in the rituximab era. Although IV rituximab mediates superior disease control of systemic non-Hodgkin lymphoma (NHL), it fails to completely eliminate the risk of meningeal recurrence, likely due to minimal CNS penetration. Given that rituximab acts synergistically with chemotherapy, we conducted the first phase 1 study of intraventricular immunochemotherapy in patients with recurrent CNS NHL. Fourteen patients received 10 mg or 25 mg intraventricular rituximab twice weekly for 4 weeks, with rituximab administered as monotherapy during the first treatment each week and rituximab administered in combination with methotrexate (MTX) during the second treatment each week. More than 150 doses were administered without serious toxicity. In a population with high-refractory CNS NHL, 75% of patients achieved complete cytologic responses and 43% achieved an overall complete response in CSF and/or brain parenchyma. Two patients achieved a first complete response of CNS NHL with intraventricular rituximab/MTX, including 1 with CNS lymphoma refractory to high-dose systemic and intrathecal MTX plus IV rituximab. We conclude that intraventricular rituximab in combination with MTX is feasible and highly active in the treatment of drug-resistant CNS NHL that is refractory or unresponsive to IV rituximab. KEY POINTS: Phase I study showed that intraventricular rituximab plus methotrexate is feasible and active in the treatment of refractory CNS lymphoma.

CXCL13 plus interleukin 10 is highly specific for the diagnosis of CNS lymphoma.

Establishing the diagnosis of focal brain lesions in patients with unexplained neurologic symptoms represents a challenge. The goal of this study is to provide evidence supporting functional roles for CXC chemokine ligand (CXCL)13 and interleukin (IL)-10 in central nervous system (CNS) lymphomas and to evaluate the utility of each as prognostic and diagnostic biomarkers. We demonstrate for the first time that elevated CXCL13 concentration in cerebrospinal fluid (CSF) is prognostic and that CXCL13 and CXCL12 mediate chemotaxis of lymphoma cells isolated from CNS lymphoma lesions. Expression of the activated form of Janus kinase 1 supported a role for IL-10 in prosurvival signaling. We determined the concentration of CXCL13 and IL-10 in CSF of CNS lymphoma patients and control cohorts including inflammatory and degenerative neurologic disease in a multicenter study involving 220 patients. Bivariate elevated CXCL13 plus IL-10 was 99.3% specific for primary and secondary CNS lymphoma, with sensitivity significantly greater than reference standard CSF tests. These results identify CXCL13 and IL-10 as potentially important biomarkers of CNS lymphoma that merit further evaluation and support incorporation of CXCL13 and IL-10 into diagnostic algorithms for the workup of focal brain lesions in which lymphoma is a consideration.

Performance of Apparent Diffusion Coefficient Values and Conventional MRI Features in Differentiating Tumefactive Demyelinating Lesions From Primary Brain Neoplasms.

OBJECTIVE: Tumefactive demyelinating lesions (TDLs) remain one of the most common brain lesions to mimic a brain tumor, particularly primary CNS lymphoma (PCNSL) and high-grade gliomas. The purpose of our study was to evaluate the ability of apparent diffusion coefficient (ADC) values and conventional MRI features to differentiate TDLs from PCNSLs and high-grade gliomas. MATERIALS AND METHODS: Seventy-five patients (24 patients with TDLs, 28 with PCNSLs, and 23 with high-grade gliomas) with 168 brain lesions (70 TDLs, 68 PCNSLs, and 30 high-grade gliomas) who underwent DWI before surgery or therapy were included in the study. Minimum ADC (ADC(min)) and average ADC (ADC(avg)) values were calculated for each lesion. ANOVA and ROC analyses were performed. ROC analyses were also performed for the presence of incomplete rim enhancement and for the number of lesions. Multiple-variable logistic regression with ROC analysis was then performed to evaluate performance in multiple-variable models. RESULTS: ADC(min) was statistically significantly higher (p < 0.01) in TDLs (mean, 0.886; 95% CI, 0.802-0.931) than in PCNSLs (0.547; 95% CI, 0.496-0.598) and high-grade gliomas (0.470; 95% CI, 0.385-0.555). (All ADC values in this article are reported in units of × 10(-3) mm(2)/s.) ADC(avg) was statistically significantly higher (p < 0.01) in TDLs (mean, 1.362; 95% CI, 1.268-1.456) than in PCNSLs (0.990; 95% CI, 0.919-1.061) but not in high-grade gliomas (1.216; 95% CI, 1.074-1.356). Multiple-variable models showed statistically significant individual effects and superior diagnostic performance on ROC analysis. CONCLUSION: TDLs can be diagnosed on preoperative MRI with a high degree of specificity; MRI features of incomplete rim enhancement, high ADC values, and a large number of lesions individually increase the probability and diagnostic confidence that a lesion is a TDL.

Prolonged Complete Response in a Pediatric Patient With Primary Peripheral T-Cell Lymphoma of the Central Nervous System.

We describe a child with a 2-week history of progressive headaches, blurry vision, and intermittent vomiting. Magnetic resonance imaging (MRI) of the brain showed a deep left hemispheric lesion with extension into the corpus callosum. Histology and immunophenotyping of the lesion was consistent with peripheral T-cell lymphoma, not otherwise specified. Chemotherapy was initiated and a complete remission was achieved. This case illustrates that a chemotherapeutic regimen used in adults with central nervous system (CNS) lymphoma can achieve durable remissions in pediatric patients with peripheral T-cell lymphoma, not otherwise specified of the CNS.

Progress in central nervous system lymphomas.

Until recently, primary central nervous system lymphoma (PCNSL) was associated with a uniformly dismal prognosis. It is now reasonable to anticipate long-term survival and possibly cure for a significant proportion of patients diagnosed with PCNSL. Accumulated data generated over the past 10 years has provided evidence that long-term progression-free survival (PFS) can reproducibly be attained in a significant fraction of PCNSL patients that receive dose-intensive chemotherapy consolidation, without whole brain radiotherapy. One consolidative regimen that has reproducibly demonstrated promise is the combination of infusional etoposide plus high-dose cytarabine (EA), administered in first complete remission after methotrexate, temozolomide and rituximab-based induction. Given evolving principles of management and the mounting evidence for reproducible improvements in survival rates in prospective clinical series, our goal in this review is to highlight and update principles in diagnosis, staging and management as well as to review data regarding the pathogenesis of central nervous system lymphomas, information that is likely to constitute a basis for the implementation of novel therapies that are requisite for further progress in this unique phenotype of non-Hodgkin lymphoma.

Utility of PD-1, PD-L1, and IDO-1 Stains in Ocular Extranodal Marginal Zone Lymphoma (MZL) and Diffuse Large B-cell Lymphoma (DLBCL).

Extranodal marginal zone lymphoma (EMZL) is the most common subtype of ocular lymphomas. Diffuse large B-cell lymphoma (DLBCL) and EMZL with large-cell transformation present diagnostic challenges. Radiotherapy is the standard treatment for ocular lymphomas, but complications and relapse are common. Diagnostic utility in challenging cases, as well as treatment options using immune checkpoint inhibitors, are unclear in ocular lymphomas. We herein investigated the PD-1, PD-L1, and IDO1 staining patterns in 20 cases of ocular lymphomas, including EMZL (n=14), EMZL with increased large cells (n=2), and DLBCL (n=4). PD-1, PD-L1, and IDO1 staining was not detected in lymphoma cells in any cases but was observed within the tumor microenvironment in all cases. Positivity for PD-1, PD-L1, and IDO1 in inflammatory cells was seen either intratumorally or peritumorally. In all 6 cases with significantly more large B cells, the density of PD-1, PD-L1, and IDO1 expression in the tumor microenvironment was higher than that of the remaining 14 cases without large B cells (P-value<0.0001), whereas other clinicopathologic features showed no statistical correlation. Increased expression of PD-1, PD-L1, and IDO1 in the inflammatory milieu in cases with large cells may provide diagnostic utility in small biopsies as well as therapeutic potential.

Myeloablative vs nonmyeloablative consolidation for primary central nervous system lymphoma: results of Alliance 51101.

ABSTRACT: Although it is evident that standard-dose whole-brain radiotherapy as consolidation is associated with significant neurotoxicity, the optimal consolidative strategy for primary central nervous system lymphoma (PCNSL) is not defined. We performed a randomized phase 2 clinical trial via the US Alliance cancer cooperative group to compare myeloablative consolidation supported by autologous stem cell transplantation with nonmyeloablative consolidation after induction therapy for PCNSL. To our knowledge, this is the first randomized trial to be initiated that eliminates whole-brain radiotherapy as a consolidative approach in newly diagnosed PCNSL. Patients aged 18 to 75 years were randomly assigned in a 1:1 manner to induction therapy (methotrexate, temozolomide, rituximab, and cytarabine) followed by consolidation with either thiotepa plus carmustine and autologous stem cell rescue vs induction followed by nonmyeloablative, infusional etoposide plus cytarabine. The primary end point was progression-free survival (PFS). A total of 113 patients were randomized, and 108 (54 in each arm) were evaluable. More patients in the nonmyeloablative arm experienced progressive disease or death during induction (28% vs 11%; P = .05). Thirty-six patients received autologous stem cell transplant, and 34 received nonmyeloablative consolidation. The estimated 2-year PFS was higher in the myeloablative vs nonmyeloablative arm (73% vs 51%; P = .02). However, a planned secondary analysis, landmarked at start of the consolidation, revealed that the estimated 2-year PFS in those who completed consolidation therapy was not significantly different between the arms (86% vs 71%; P = .21). Both consolidative strategies yielded encouraging efficacy and similar toxicity profiles. This trial was registered at www.clininicals.gov as #NCT01511562.

Liquid biopsy for improving diagnosis and monitoring of CNS lymphomas: A RANO review.

BACKGROUND: The utility of liquid biopsies is well documented in several extracranial and intracranial (brain/leptomeningeal metastases, gliomas) tumors. METHODS: The RANO (Response Assessment in Neuro-Oncology) group has set up a multidisciplinary Task Force to critically review the role of blood and cerebrospinal fluid (CSF)-liquid biopsy in CNS lymphomas, with a main focus on primary central nervous system lymphomas (PCNSL). RESULTS: Several clinical applications are suggested: diagnosis of PCNSL in critical settings (elderly or frail patients, deep locations, and steroid responsiveness), definition of minimal residual disease, early indication of tumor response or relapse following treatments, and prediction of outcome. CONCLUSIONS: Thus far, no clinically validated circulating biomarkers for managing both primary and secondary CNS lymphomas exist. There is need of standardization of biofluid collection, choice of analytes, and type of technique to perform the molecular analysis. The various assays should be evaluated through well-organized central testing within clinical trials.

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.

Stereotactic Radiosurgery for Primary Central Nervous System Lymphoma.

Background Primary central nervous system lymphoma (PCNSL) is rare, with a treatment backbone that typically includes high-dose methotrexate-based chemotherapy, with radiation often reserved for persistent or progressive disease. In this study, we report the outcomes of stereotactic radiosurgery (SRS) in patients with PCNSL to potentially defer whole brain radiotherapy (WBRT) or as salvage after WBRT. Methodology We performed a single-institution, retrospective review of 20 patients with PCNSL who received single-fraction or fractionated SRS to 32 lesions between September 1992 and July 2019. Results The median age at SRS was 67 years (interquartile range (IQR) = 56-74 years). The median Karnofsky Performance Status (KPS) at SRS was 80 (IQR = 50-80). In total, 18 (90%) patients received methotrexate-based chemotherapy prior to SRS, with a median of eight cycles (IQR = 5-10). A total of 10 patients received SRS for recurrent disease after chemotherapy and/or WBRT, nine patients received SRS for the persistent disease after chemotherapy alone, and one patient received up-front SRS. Overall, five patients received SRS following WBRT. The median SRS dose was 16 Gy (IQR = 14-22.5 Gy) in one fraction (IQR = 1-5 fractions). Eight patients (40%) were treated with consolidative pomalidomide or lenalidomide following SRS. The local control rate was 100% (32/32 lesions at a median follow-up of 15 months). In total, 13 of 16 (81%) patients with available follow-up experienced distant brain recurrence. The median time to distant failure following SRS was 10 months (IQR = 1-16 months). Three patients received salvage SRS, and three patients received salvage WBRT. The median overall survival from diagnosis was 39 months (95% confidence interval = 24-54 months). KPS at the time of SRS was significantly correlated with time to progression (p = 0.002). The use of lenalidomide or pomalidomide after SRS was associated with improved overall survival after SRS (three vs. 14 months, p = 0.035). Consolidative etoposide and cytarabine after initial methotrexate-based chemotherapy was also associated with improved survival following SRS (eight vs. 47 months, p = 0.028). Conclusions SRS offers effective local tumor control for patients with PCNSL; however, the majority of patients experience distant progression. SRS may have a role in the salvage setting for patients with recurrence after WBRT, or allow deferral of WBRT in select patients, although systemic therapy appears to strongly influence outcomes in this cohort.

EBV-positive PCNSL in older patients: incidence, characteristics, tumor pathology, and outcomes across a large multicenter cohort.

The objective of this multicenter retrospective study was to examine the incidence, patient characteristics, pathology, and outcomes associated with Epstein-Barr virus (EBV)-related CNS lymphoma (CNSL) in older patients. Among 309 CNSL patients aged ≥60, 11.7% had EBV + tumors of which 72.2% were solid organ transplant (SOT)-related post-transplant lymphoproliferative disorders (PTLD). Younger age, SOT or autoimmune disease, and immunosuppressive treatment correlated highly with EBV-positivity. EBV + tumors were associated with absent C-MYC and BCL6 expression. EBV + PTLD was more likely to be associated with the absence of CD5 expression. EBV + non-PTLD had better median OS (not reached) compared to EBV + PTLD (10.8 months) and EBV-negative patients (43 months). Multivariable Cox regression analysis showed that age, performance status, and PTLD were negative predictors of OS. EBV status and immunosuppressive treatment were not correlated with OS. Our findings merit further investigation of EBV + PCNSL tumors and EBV-directed therapies.

Efficacy of the ketogenic diet in Lennox-Gastaut syndrome: a retrospective review of one institution's experience and summary of the literature.

AIM: To determine the efficacy of the ketogenic diet for children with Lennox-Gastaut syndrome (LGS) at our institution and in the literature. METHOD: The records of children with LGS initiated on the ketogenic diet at our institution from 1994 to 2010 were reviewed. Inclusion criteria included the presence of ≤2.5Hz spike-and-wave complexes on electroencephalogram, multiple seizure types including tonic, atonic, or atypical absence, developmental delay, and age under 1 year. We additionally reviewed the literature for cases of LGS treated with the ketogenic diet and their outcomes. RESULTS: Seventy-one children (41 males, 30 females, median age 3y 6mo, range 18mo-18y), with LGS were initiated on the ketogenic diet. Using an intent-to-treat analysis, after 6 months, 36 (51%) achieved more than 50% seizure reduction, 16 (23%) experienced more than 90% seizure reduction, and 1 (1%) achieved seizure freedom. Results were similar after 12 months. Age, sex, side effects, valproate use, and history of infantile spasms were not predictive of more than 90% seizure reduction. In the literature, 88 of 189 (47%) children with LGS had more than 50% seizure reduction after 3 to 36 months of ketogenic diet treatment. INTERPRETATION: The ketogenic diet is efficacious in the treatment of LGS, with approximately one-half of children responding at 12 months.