Distinct peripheral T-cell and NK-cell profiles in HGBL-MYC/BCL2 vs patients with DLBCL NOS.

ABSTRACT: Patients with high-grade B-cell lymphoma with MYC and BCL2 rearrangements (HGBL-MYC/BCL2) respond poorly to immunochemotherapy compared with patients with diffuse large B-cell lymphoma not otherwise specified (DLBCL NOS) without a MYC rearrangement. This suggests a negative impact of lymphoma-intrinsic MYC on the immune system. To investigate this, we compared circulating T cells and natural killer (NK) cells of patients with HGBL-MYC/BCL2 (n = 66), patients with DLBCL NOS (n = 53), and age-matched healthy donors (HDs; n = 16) by flow cytometry and performed proliferation, cytokine production, and cytotoxicity assays. Compared with HDs, both lymphoma subtypes displayed similar frequencies of CD8+ T cells but decreased CD4+ T cells. Regulatory T-cell (Treg) frequencies were reduced only in patients with DLBCL NOS. Activated (HLA-DR+/CD38+) T cells, PD-1+CD4+ T cells, and PD-1+Tregs were increased in both lymphoma subtypes, but PD-1+CD8+ T cells were increased only in HGBL-MYC/BCL2. Patients with DLBCL NOS, but not patients with HGBL-MYC/BCL2, exhibited higher frequencies of senescent T cells than HDs. Functional assays showed no overt differences between both lymphoma groups and HDs. Deeper analyses revealed that PD-1+ T cells of patients with HGBL-MYC/BCL2 were exhausted with impaired cytokine production and degranulation. Patients with DLBCL NOS, but not patients with HGBL-MYC/BCL2, exhibited higher frequencies of NK cells expressing inhibiting receptor NKG2A. Both lymphoma subtypes exhibited lower TIM-3+- and DNAM-1+-expressing NK cells. Although NK cells of patients with HGBL-MYC/BCL2 showed less degranulation, they were not defective in cytotoxicity. In conclusion, our results demonstrate an increased exhaustion in circulating T cells of patients with HGBL-MYC/BCL2. Nonetheless, the overall intact peripheral T-cell and NK-cell functions in these patients emphasize the importance of investigating potential immune evasion in the microenvironment of MYC-rearranged lymphomas.

Multi-scale spatial modeling of immune cell distributions enables survival prediction in primary central nervous system lymphoma.

To understand the clinical significance of the tumor microenvironment (TME), it is essential to study the interactions between malignant and non-malignant cells in clinical specimens. Here, we established a computational framework for a multiplex imaging system to comprehensively characterize spatial contexts of the TME at multiple scales, including close and long-distance spatial interactions between cell type pairs. We applied this framework to a total of 1,393 multiplex imaging data newly generated from 88 primary central nervous system lymphomas with complete follow-up data and identified significant prognostic subgroups mainly shaped by the spatial context. A supervised analysis confirmed a significant contribution of spatial context in predicting patient survival. In particular, we found an opposite prognostic value of macrophage infiltration depending on its proximity to specific cell types. Altogether, we provide a comprehensive framework to analyze spatial cellular interaction that can be broadly applied to other technologies and tumor contexts.

Large B-cell Lymphomas of Immune-Privileged Sites Relapse via Parallel Clonal Evolution from a Common Progenitor B Cell.

Large B-cell lymphoma of immune-privileged sites (LBCL-IP) arise in immune sanctuaries including the testis and central nervous system (CNS). After initially reaching complete response, relapses occur in almost 50% of patients, typically at other immune-privileged sites. Resolution of the clonal relationships and evolutionary patterns of LBCL-IP is required to understand the unique clinical behavior. We collected a unique set of 33 primary-relapse LBCL-IP sample pairs and performed next-generation sequencing for copy number, mutation, translocation, and immunoglobulin clonality analysis. All LBCL-IP sample pairs were clonally related, and both tumors developed from a common progenitor cell (CPC) with MYD88 and TBL1XR1 mutations and/or BCL6 translocations in 30/33 cases, indicating that these are early genetic events. This was succeeded by intermediate genetic events including shared, as well as unique alterations in targets of aberrant somatic hypermutation (aSHM), CD79B mutations, and 9p21.3/CDKN2A loss. Genetic alterations in genes involved in immune escape (HLA, CD274/PDCD1LG2) were predominantly unique in primary and relapse samples and thus considered late genetic events. Together, this study indicates that primary and relapsed LBCL-IP follow an early parallel evolutionary pattern where the CPC contains genetic alterations that support prolonged survival/proliferation and retention in a memory B-cell state, followed by germinal center reentry, aSHM and immune escape. SIGNIFICANCE: Genomic analyses reveal that primary and relapse LBCL-IP originate from a common progenitor cell with a small set of genetic alterations, followed by extensive parallel diversification, elucidating the clonal evolution of LBCL-IP.

The path towards consensus genome classification of diffuse large B-cell lymphoma for use in clinical practice.

Diffuse large B-cell lymphoma (DLBCL) is a widely heterogeneous disease in presentation, treatment response and outcome that results from a broad biological heterogeneity. Various stratification approaches have been proposed over time but failed to sufficiently capture the heterogeneous biology and behavior of the disease in a clinically relevant manner. The most recent DNA-based genomic subtyping studies are a major step forward by offering a level of refinement that could serve as a basis for exploration of personalized and targeted treatment for the years to come. To enable consistent trial designs and allow meaningful comparisons between studies, harmonization of the currently available knowledge into a single genomic classification widely applicable in daily practice is pivotal. In this review, we investigate potential avenues for harmonization of the presently available genomic subtypes of DLBCL inspired by consensus molecular classifications achieved for other malignancies. Finally, suggestions for laboratory techniques and infrastructure required for successful clinical implementation are described.

Genomic and microenvironmental landscape of stage I follicular lymphoma, compared with stage III/IV.

Although the genomic and immune microenvironmental landscape of follicular lymphoma (FL) has been extensively investigated, little is known about the potential biological differences between stage I and stage III/IV disease. Using next-generation sequencing and immunohistochemistry, 82 FL nodal stage I cases were analyzed and compared with 139 FL stage III/IV nodal cases. Many similarities in mutations, chromosomal copy number aberrations, and microenvironmental cell populations were detected. However, there were also significant differences in microenvironmental and genomic features. CD8+ T cells (P = .02) and STAT6 mutations (false discovery rate [FDR] <0.001) were more frequent in stage I FL. In contrast, programmed cell death protein 1-positive T cells, CD68+/CD163+ macrophages (P < .001), BCL2 translocation (BCL2trl+) (P < .0001), and KMT2D (FDR = 0.003) and CREBBP (FDR = 0.04) mutations were found more frequently in stage III/IV FL. Using clustering, we identified 3 clusters within stage I, and 2 clusters within stage III/IV. The BLC2trl+ stage I cluster was comparable to the BCL2trl+ cluster in stage III/IV. The two BCL2trl- stage I clusters were unique for stage I. One was enriched for CREBBP (95%) and STAT6 (64%) mutations, without BLC6 translocation (BCL6trl), whereas the BCL2trl- stage III/IV cluster contained BCL6trl (64%) with fewer CREBBP (45%) and STAT6 (9%) mutations. The other BCL2trl- stage I cluster was relatively heterogeneous with more copy number aberrations and linker histone mutations. This exploratory study shows that stage I FL is genetically heterogeneous with different underlying oncogenic pathways. Stage I FL BCL2trl- is likely STAT6 driven, whereas BCL2trl- stage III/IV appears to be more BCL6trl driven.

A multi-platform reference for somatic structural variation detection.

Accurate detection of somatic structural variation (SV) in cancer genomes remains a challenging problem. This is in part due to the lack of high-quality, gold-standard datasets that enable the benchmarking of experimental approaches and bioinformatic analysis pipelines. Here, we performed somatic SV analysis of the paired melanoma and normal lymphoblastoid COLO829 cell lines using four different sequencing technologies. Based on the evidence from multiple technologies combined with extensive experimental validation, we compiled a comprehensive set of carefully curated and validated somatic SVs, comprising all SV types. We demonstrate the utility of this resource by determining the SV detection performance as a function of tumor purity and sequence depth, highlighting the importance of assessing these parameters in cancer genomics projects. The truth somatic SV dataset as well as the underlying raw multi-platform sequencing data are freely available and are an important resource for community somatic benchmarking efforts.

PCR-Free Shallow Whole Genome Sequencing for Chromosomal Copy Number Detection from Plasma of Cancer Patients Is an Efficient Alternative to the Conventional PCR-Based Approach.

Somatic copy number alterations can be detected in cell-free DNA (cfDNA) by shallow whole genome sequencing (sWGS). PCR is typically included in library preparations, but a PCR-free method could serve as a high-throughput alternative. To evaluate a PCR-free method for research and diagnostics, archival peripheral blood or bone marrow plasma samples, collected in EDTA- or lithium-heparin-containing tubes, were collected from patients with non-small-cell lung cancer (n = 10 longitudinal samples; 4 patients), B-cell lymphoma (n = 31), and acute myeloid leukemia (n = 15), or from healthy donors (n = 14). sWGS was performed on PCR-free and PCR library preparations, and the mapping quality, percentage of unique reads, genome coverage, fragment lengths, and copy number profiles were compared. The percentage of unique reads was significantly higher for PCR-free method compared with PCR method, independent of the type of collection tube: EDTA PCR-free method, 96.4% (n = 35); EDTA PCR method, 85.1% (n = 32); heparin PCR-free method, 94.5% (n = 25); and heparin PCR method, 89.4% (n = 10). All other evaluated metrics were highly comparable for PCR-free and PCR library preparations. These results demonstrate the feasibility of somatic copy number alteration detection by PCR-free sWGS using cfDNA from plasma collected in EDTA- or lithium-heparin-containing tubes and pave the way for an automated cfDNA analysis workflow for samples from cancer patients.

Extracellular vesicle miRNA predict FDG-PET status in patients with classical Hodgkin Lymphoma.

Minimally-invasive tools to assess tumour presence and burden may improve clinical management. FDG-PET (metabolic) imaging is the current gold standard for interim response assessment in patients with classical Hodgkin Lymphoma (cHL), but this technique cannot be repeated frequently. Here we show that microRNAs (miRNA) associated with tumour-secreted extracellular vesicles (EVs) in the circulation of cHL patients may improve response assessment. Small RNA sequencing and qRT-PCR reveal that the relative abundance of cHL-expressed miRNAs, miR-127-3p, miR-155-5p, miR-21-5p, miR-24-3p and let-7a-5p is up to hundred-fold increased in plasma EVs of cHL patients pre-treatment when compared to complete metabolic responders (CMR). Notably, in partial responders (PR) or treatment-refractory cases (n = 10) the EV-miRNA levels remain elevated. In comparison, tumour specific copy number variations (CNV) were detected in cell-free DNA of 8 out of 10 newly diagnosed cHL patients but not in patients with PR. Combining EV-miR-127-3p and/or EV-let-7a-5p levels, with serum TARC (a validated protein cHL biomarker), increases the accuracy for predicting PET-status (n = 129) to an area under the curve of 0.93 (CI: 0.87-0.99), 93.5% sensitivity, 83.8/85.0% specificity and a negative predictive value of 96%. Thus the level of tumour-associated miRNAs in plasma EVs is predictive of metabolic tumour activity in cHL patients. Our findings suggest that plasma EV-miRNA are useful for detection of small residual lesions and may be applied as serial response prediction tool.

Clinical Validation of Whole Genome Sequencing for Cancer Diagnostics.

Whole genome sequencing (WGS) using fresh-frozen tissue and matched blood samples from cancer patients may become the most complete genetic tumor test. With the increasing availability of small biopsies and the need to screen more number of biomarkers, the use of a single all-inclusive test is preferable over multiple consecutive assays. To meet high-quality diagnostics standards, we optimized and clinically validated WGS sample and data processing procedures, resulting in a technical success rate of 95.6% for fresh-frozen samples with sufficient (≥20%) tumor content. Independent validation of identified biomarkers against commonly used diagnostic assays showed a high sensitivity (recall; 98.5%) and precision (positive predictive value; 97.8%) for detection of somatic single-nucleotide variants and insertions and deletions (across 22 genes), and high concordance for detection of gene amplification (97.0%; EGFR and MET) as well as somatic complete loss (100%; CDKN2A/p16). Gene fusion analysis showed a concordance of 91.3% between DNA-based WGS and an orthogonal RNA-based gene fusion assay. Microsatellite (in)stability assessment showed a sensitivity of 100% with a precision of 94%, and virus detection (human papillomavirus), an accuracy of 100% compared with standard testing. In conclusion, whole genome sequencing has a >95% sensitivity and precision compared with routinely used DNA techniques in diagnostics, and all relevant mutation types can be detected reliably in a single assay.

Epcoritamab induces potent anti-tumor activity against malignant B-cells from patients with DLBCL, FL and MCL, irrespective of prior CD20 monoclonal antibody treatment.

Epcoritamab (DuoBody-CD3xCD20, GEN3013) is a novel bispecific IgG1 antibody redirecting T-cells toward CD20+ tumor cells. Here, we assessed the preclinical efficacy of epcoritamab against primary tumor cells present in the lymph node biopsies from newly diagnosed (ND) and relapsed/refractory (RR) B-NHL patients. In the presence of T-cells from a healthy donor, epcoritamab demonstrated potent activity against primary tumor cells, irrespective of prior treatments, including CD20 mAbs. Median lysis of 65, 74, and 84% were achieved in diffuse large B-cell lymphoma (n = 16), follicular lymphoma (n = 15), and mantle cell lymphoma (n = 8), respectively. Furthermore, in this allogeneic setting, we discovered that the capacity of B-cell tumors to activate T-cells was heterogeneous and showed an inverse association with their surface expression levels of the immune checkpoint molecule Herpesvirus Entry Mediator (HVEM). In the autologous setting, when lymph node (LN)-residing T-cells were the only source of effector cells, the epcoritamab-dependent cytotoxicity strongly correlated with local effector cell-to-target cell ratios. Further analyses revealed that LN-residing-derived or peripheral blood-derived T-cells of B-NHL patients, as well as heathy donor T-cells equally mediated epcoritamab-dependent cytotoxicity. These results show the promise of epcoritamab for treatment of newly-diagnosed or relapsed/refractory B-NHL patients, including those who became refractory to previous CD20-directed therapies.

In-depth cell-free DNA sequencing reveals genomic landscape of Hodgkin's lymphoma and facilitates ultrasensitive residual disease detection.

BACKGROUND: Individualization of treatment in Hodgkin's lymphoma is necessary to improve cure rates and reduce treatment side effects. Currently, it is hindered by a lack of genomic characterization and sensitive molecular response assessment. Sequencing of cell-free DNA is a powerful strategy to understand the cancer genome and can be used for extremely sensitive disease monitoring. In Hodgkin's lymphoma, a high proportion of cell-free DNA is tumor-derived, whereas traditional tumor biopsies only contain a little tumor-derived DNA. METHODS: We comprehensively genotype and assess minimal residual disease in 121 patients with baseline plasma as well as 77 follow-up samples from a subset of patients with our targeted cell-free DNA sequencing platform. FINDINGS: We present an integrated landscape of mutations and copy number variations in Hodgkin's lymphoma. In addition, we perform a deep analysis of mutational processes driving Hodgkin's lymphoma, investigate the clonal structure of Hodgkin's lymphoma, and link several genotypes to Hodgkin's lymphoma phenotypes and outcome. Finally, we show that minimal residual disease assessment by repeat cell-free DNA sequencing, as early as a week after treatment initiation, predicts treatment response and progression-free survival, allowing highly improved treatment guidance and relapse prediction. CONCLUSIONS: Our targeted cell-free DNA sequencing platform reveals the genomic landscape of Hodgkin's lymphoma and facilitates ultrasensitive detection of minimal residual disease. FUNDING: Mildred Scheel School of Oncology Aachen-Bonn-Cologne-Düsseldorf MD Research Stipend, Next Generation Sequencing Competence Network grant 423957469, Deutsche Krebshilfe grant 70112502, Deutsche Forschungsgemeinschaft (DFG) grant EN 179/13-1, the HL MRD consortium, and the Frau-Weiskam und Christel Ruranski-Stiftung.

Spatial signatures identify immune escape via PD-1 as a defining feature of T-cell/histiocyte-rich large B-cell lymphoma.

T-cell/histiocyte-rich large B-cell lymphoma (TCRLBCL) is an aggressive variant of diffuse large B-cell lymphoma (DLBCL) characterized by rare malignant B cells within a robust but ineffective immune cell infiltrate. The mechanistic basis of immune escape in TCRLBCL is poorly defined and not targeted therapeutically. We performed a genetic and quantitative spatial analysis of the PD-1/PD-L1 pathway in a multi-institutional cohort of TCRLBCLs and found that malignant B cells harbored PD-L1/PD-L2 copy gain or amplification in 64% of cases, which was associated with increased PD-L1 expression (P = .0111). By directed and unsupervised spatial analyses of multiparametric cell phenotypic data within the tumor microenvironment, we found that TCRLBCL is characterized by tumor-immune "neighborhoods" in which malignant B cells are surrounded by exceptionally high numbers of PD-L1-expressing TAMs and PD-1+ T cells. Furthermore, unbiased clustering of spatially resolved immune signatures distinguished TCRLBCL from related subtypes of B-cell lymphoma, including classic Hodgkin lymphoma (cHL) and DLBCL-NOS. Finally, we observed clinical responses to PD-1 blockade in 3 of 5 patients with relapsed/refractory TCRLBCL who were enrolled in clinical trials for refractory hematologic malignancies (NCT03316573; NCT01953692), including 2 complete responses and 1 partial response. Taken together, these data implicate PD-1 signaling as an immune escape pathway in TCRLBCL and also support the potential utility of spatially resolved immune signatures to aid the diagnostic classification and immunotherapeutic prioritization of diverse tumor types.

Chromosome 20 loss is characteristic of breast implant-associated anaplastic large cell lymphoma.

Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is a very rare type of T-cell lymphoma that is uniquely caused by a single environmental stimulus. Here, we present a comprehensive genetic analysis of a relatively large series of BIA-ALCL (n = 29), for which genome-wide chromosomal copy number aberrations (CNAs) and mutational profiles for a subset (n = 7) were determined. For comparison, CNAs for anaplastic lymphoma kinase (ALK)- nodal anaplastic large cell lymphomas (ALCLs; n = 24) were obtained. CNAs were detected in 94% of BIA-ALCLs, with losses at chromosome 20q13.13 in 66% of the samples. Loss of 20q13.13 is characteristic of BIA-ALCL compared with other classes of ALCL, such as primary cutaneous ALCL and systemic type ALK+ and ALK- ALCL. Mutational patterns confirm that the interleukin-6-JAK1-STAT3 pathway is deregulated. Although this is commonly observed across various types of T-cell lymphomas, the extent of deregulation is significantly higher in BIA-ALCL, as indicated by phosphorylated STAT3 immunohistochemistry. The characteristic loss of chromosome 20 in BIA-ALCL provides further justification to recognize BIA-ALCL as a separate disease entity. Moreover, CNA analysis may serve as a parameter for future diagnostic assays for women with breast implants to distinguish seroma caused by BIA-ALCL from other causes of seroma accumulation, such as infection or trauma.

Impact of MYC on Anti-Tumor Immune Responses in Aggressive B Cell Non-Hodgkin Lymphomas: Consequences for Cancer Immunotherapy.

Patients with MYC overexpressing high grade B cell lymphoma (HGBL) face significant dismal prognosis after treatment with standard immunochemotherapy regimens. Recent preclinical studies indicate that MYC not only contributes to tumorigenesis by its effects on cell proliferation and differentiation, but also plays an important role in promoting escape from anti-tumor immune responses. This is of specific interest, since reversing tumor immune inhibition with immunotherapy has shown promising results in the treatment of both solid tumors and hematological malignancies. In this review, we outline the current understanding of impaired immune responses in B cell lymphoid malignancies with MYC overexpression, with a particular emphasis on diffuse large B cell lymphoma. We also discuss clinical consequences of MYC overexpression in the treatment of HGBL with novel immunotherapeutic agents and potential future treatment strategies.

PD-L1 and PD-L2 Expression in Cervical Cancer: Regulation and Biomarker Potential.

PD-1/PD-L1 immune checkpoint inhibitors show potential for cervical cancer treatment. However, low response rates suggest that patient selection based on PD-L1 protein expression is not optimal. Here, we evaluated different PD-L1 detection methods and studied transcriptional regulation of PD-L1/PD-L2 expression by The Cancer Genome Atlas (TCGA) mRNAseq analysis. First, we determined the copy number of the PD-L1/PD-L2 locus by fluorescence in situ hybridization (FISH), PD-L1 mRNA expression by RNA in situ hybridization (RNAish), and PD-L1/PD-L2 protein expression by immunohistochemistry (IHC) on tissue microarrays containing a cohort of 60 patients. Additionally, distribution of PD-L1/PD-L2 was visualized based on flow cytometry analysis of single-cell suspensions (n = 10). PD-L1/PD-L2 locus amplification was rare (2%). PD-L1 mRNA expression in tumor cells was detected in 56% of cases, while 41% expressed PD-L1 protein. Discordant scores for PD-L1 protein expression on tumor cells between cores from one patient were observed in 27% of cases. Interestingly, with RNAish, PD-L1 heterogeneity was observed in only 11% of the cases. PD-L2 protein expression was found in 53%. PD-L1 mRNA and protein expression on tumor cells were strongly correlated (p < 0.001). PD-L1 and PD-L2 protein expression showed no correlation on tumor cells (p = 0.837), but a strong correlation on cells in stromal fields (p < 0.001). Co-expression of PD-L1 and PD-L2 on macrophage-like populations was also observed with flow cytometry analysis. Both PD-L1 and PD-L2 TCGA transcript levels strongly correlated in the TCGA data, and both PD-L1 and PD-L2 strongly correlated with interferon gamma (IFNG) expression/transcript levels (p < 0.0001). Importantly, patients with high PD-L1/PD-L2/IFNG transcript levels had a survival advantage over patients with high PD-L1/PD-L2 and low IFNG expression. Based on these findings, we conclude that PD-L1/PD-L2 expression in cervical cancer is mainly associated with interferon induction and not gene amplification, which makes FISH unsuitable as biomarker. The heterogeneous PD-L1 and PD-L2 expression patterns suggest IHC unreliable for patient selection. RNAish, in conjunction with interferon signaling evaluation, seems a promising technique for immune checkpoint detection. These results warrant further investigation into their prognostic and predictive potential.

High frequency of inactivating tetraspanin C D37 mutations in diffuse large B-cell lymphoma at immune-privileged sites.

Tetraspanin CD37 is predominantly expressed on the cell surface of mature B lymphocytes and is currently being studied as novel therapeutic target for B-cell lymphoma. Recently, we demonstrated that loss of CD37 induces spontaneous B-cell lymphoma in Cd37-knockout mice and correlates with inferior survival in patients with diffuse large B-cell lymphoma (DLBCL). Here, CD37 mutation analysis was performed in a cohort of 137 primary DLBCL samples, including 44 primary immune-privileged site-associated DLBCL (IP-DLBCL) samples originating in the testis or central nervous system. CD37 mutations were exclusively identified in IP-DLBCL cases (10/44, 23%) but absent in non-IP-DLBCL cases. The aberrations included 10 missense mutations, 1 deletion, and 3 splice-site CD37 mutations. Modeling and functional analysis of CD37 missense mutations revealed loss of function by impaired CD37 protein expression at the plasma membrane of human lymphoma B cells. This study provides novel insight into the molecular pathogenesis of IP-DLBCL and indicates that anti-CD37 therapies will be more beneficial for DLBCL patients without CD37 mutations.

Nivolumab for Relapsed/Refractory Diffuse Large B-Cell Lymphoma in Patients Ineligible for or Having Failed Autologous Transplantation: A Single-Arm, Phase II Study.

PURPOSE: Treatment options are limited for patients with relapsed/refractory diffuse large B-cell lymphoma (DLBCL). Tumor cells can exploit the programmed death-1 checkpoint pathway to evade immune surveillance. In the current study, we evaluated the efficacy and safety of programmed death-1 blockade by nivolumab in patients with relapsed/refractory DLBCL. METHODS: In this phase II, open-label study, patients with relapsed/refractory DLBCL who were ineligible for autologous hematopoietic cell transplantation (auto-HCT) or who had experienced failure with auto-HCT received nivolumab 3 mg/kg every 2 weeks. We assessed the efficacy and safety of nivolumab as well as genetic alterations of 9p24.1. RESULTS: Among 121 treated patients, patients in the auto-HCT-failed cohort (n = 87) received a median of four nivolumab doses and a median of three doses were administered to those in the auto-HCT-ineligible cohort (n = 34). At a median follow-up of 9 months in the auto-HCT-failed cohort and 6 months in the auto-HCT-ineligible cohort, independently assessed objective response rates were 10% and 3%, and median durations of response were 11 and 8 months, respectively. Median progression-free survival and overall survival were 1.9 and 12.2 months in the auto-HCT-failed cohort and 1.4 and 5.8 months in the auto-HCT-ineligible cohort respectively. All three patients with complete remission-3% of the auto-HCT-failed cohort-had durable response (11 or more, 14 or more, and 17 months). Treatment-related grade 3 and 4 adverse events were reported in 24% of patients. The most common were neutropenia (4%), thrombocytopenia (3%), and increased lipase (3%). Of all evaluable samples for 9p24.1 analysis, 16% exhibited low-level copy gain and 3% had amplification. CONCLUSION: Nivolumab monotherapy is associated with a favorable safety profile but a low overall response rate among patients with DLBCL who are ineligible for auto-HCT or who experienced failure with auto-HCT. Genetic alterations of 9p24.1 are infrequent in DLBCL.

IGFBP7 Induces Differentiation and Loss of Survival of Human Acute Myeloid Leukemia Stem Cells without Affecting Normal Hematopoiesis.

Leukemic stem cells (LSCs) are thought to be the major cause of the recurrence of acute myeloid leukemia (AML) due to their potential for self-renewal. To identify therapeutic strategies targeting LSCs, while sparing healthy hematopoietic stem cells (HSCs), we performed gene expression profiling of LSCs, HSCs, and leukemic progenitors all residing within the same AML bone marrow and identified insulin-like growth factor-binding protein 7 (IGFBP7) as differentially expressed. Low IGFBP7 is a feature of LSCs and is associated with reduced chemotherapy sensitivity. Enhancing IGFBP7 by overexpression or addition of recombinant human IGFBP7 (rhIGFBP7) resulted in differentiation, inhibition of cell survival, and increased chemotherapy sensitivity of primary AML cells. Adding rhIGFBP7 reduced leukemic stem and/or progenitor survival and reversed a stem-like gene signature, but it had no influence on normal hematopoietic stem cell survival. Our data suggest a potential clinical utility of the addition of rhIGFBP7 to current chemotherapy regimens to decrease AML relapse rates.