Gunther Glehr

Bio: Gunther Glehr is an academic researcher from University of Regensburg. The author has contributed to research in topics: Immune checkpoint & Medicine. The author has an hindex of 2, co-authored 5 publications receiving 17 citations.

A novel lymphoma-associated macrophage interaction signature (LAMIS) provides robust risk prognostication in diffuse large B-cell lymphoma clinical trial cohorts of the DSHNHL

Abstract: Diffuse large B-cell lymphoma (DLBCL) is a disease with heterogeneous outcome. Stromal signatures have been correlated to survival in DLBCL. Their use, however, is hampered by the lack of assays for formalin-fixed paraffin-embedded material (FFPE). We constructed a lymphoma-associated macrophage interaction signature (LAMIS) interrogating features of the microenvironment using a NanoString assay applicable to FFPE. The clinical impact of the signature could be validated in a cohort of 466 patients enrolled in prospective clinical trials of the German High-Grade Non-Hodgkin Lymphoma Study Group (DSHNHL). Patients with high expression of the signature (LAMIShigh) had shorter EFS, PFS, and OS. Multivariate analyses revealed independence from IPI factors in EFS (HR 1.7, 95% CI 1.2–2.4, p-value = 0.001), PFS (HR 1.8, 95% CI 1.2–2.5, p-value = 0.001) and OS (HR 1.8, 95% CI 1.3–2.7, p-value = 0.001). Multivariate analyses adjusted for the IPI factors showed the signature to be independent from COO, MYC rearrangements and double expresser status (DE). LAMIShigh and simultaneous DE status characterized a patient subgroup with dismal prognosis and early relapse. Our data underline the importance of the microenvironment in prognosis. Combined analysis of stromal features, the IPI and DE may provide a new rationale for targeted therapy.

Virus-specific memory T cell responses unmasked by immune checkpoint blockade cause hepatitis

Abstract: Treatment of advanced melanoma with combined PD-1/CTLA-4 blockade commonly causes serious immune-mediated complications. Here, we identify a subset of patients predisposed to immune checkpoint blockade-related hepatitis who are distinguished by chronic expansion of effector memory CD4+ T cells (TEM cells). Pre-therapy CD4+ TEM cell expansion occurs primarily during autumn or winter in patients with metastatic disease and high cytomegalovirus (CMV)-specific serum antibody titres. These clinical features implicate metastasis-dependent, compartmentalised CMV reactivation as the cause of CD4+ TEM expansion. Pre-therapy CD4+ TEM expansion predicts hepatitis in CMV-seropositive patients, opening possibilities for avoidance or prevention. 3 of 4 patients with pre-treatment CD4+ TEM expansion who received αPD-1 monotherapy instead of αPD-1/αCTLA-4 therapy remained hepatitis-free. 4 of 4 patients with baseline CD4+ TEM expansion given prophylactic valganciclovir and αPD-1/αCTLA-4 therapy remained hepatitis-free. Our findings exemplify how pathogen exposure can shape clinical reactions after cancer therapy and how this insight leads to therapeutic innovations.

Gene expression-based outcome prediction in advanced stage classical Hodgkin lymphoma treated with BEACOPP

Abstract: Classical Hodgkin Lymphoma (cHL) is a B cell-derived lymphoid malignancy, affecting 2.5–3/100,000 people per year. To date, in patients diagnosed with advanced cHL no reliable tool is able to—a priori—distinguish the subset of patients at high risk for relapse or refractory disease. Clinical risk indices for cHL, such as the International Prognostic Score (IPS), have not been successfully applied as a treatment decision tool in advanced stage cHL [1]. In this study we show, that a previously published gene expression-based predictor in advanced stage cHL patients treated with ABVD [2] does not prove prognostic in 401 BEACOPP-treated advanced stage cHL patients. Using transcriptome profiling, we identified however that three individual genes, PDGFRA, TNFRSF8 (encoding CD30) and CCL17 (encoding TARC), were significantly associated with progression-free survival (PFS) after multiple test correction in the BEACOPP-treated cohort, highlighting the potential of a modified gene expression profiling approach for pre-treatment risk assessment.

External validation of biomarkers for immune-related adverse events after immune checkpoint inhibition

Abstract: Immune checkpoint inhibitors have revolutionized treatment of advanced melanoma, but commonly cause serious immune-mediated complications. The clinical ambition of reserving more aggressive therapies for patients least likely to experience immune-related adverse events (irAE) has driven an extensive search for predictive biomarkers. Here, we externally validate the performance of 59 previously reported markers of irAE risk in a new cohort of 110 patients receiving Nivolumab (anti-PD1) and Ipilimumab (anti-CTLA-4) therapy. Alone or combined, the discriminatory value of these routine clinical parameters and flow cytometry biomarkers was poor. Unsupervised clustering of flow cytometry data returned four T cell subsets with higher discriminatory capacity for colitis than previously reported populations, but they cannot be considered as reliable classifiers. Although mechanisms predisposing some patients to particular irAEs have been described, we are presently unable to capture adequate information from pre-therapy flow cytometry and clinical data to reliably predict risk of irAE in most cases.

Development of a Flow Cytometry Assay to Predict Immune Checkpoint Blockade-Related Complications

Abstract: Treatment of advanced melanoma with combined immune checkpoint inhibitor (ICI) therapy is complicated in up to 50 % of cases by immune-related adverse events (irAE) that commonly include hepatitis, colitis and skin reactions. We previously reported that pre-therapy expansion of cytomegalovirus (CMV)-reactive CD4+ effector memory T cells (TEM) predicts ICI-related hepatitis in a subset of patients with Stage IV melanoma given αPD-1 and αCTLA-4. Here, we develop and validate a 10-color flow cytometry panel for reliably quantifying CD4+ TEM cells and other biomarkers of irAE risk in peripheral blood samples. Compared to previous methods, our new panel performs equally well in measuring CD4+ TEM cells (agreement = 98 %) and is superior in resolving CD4+ CD197+ CD45RA- central memory T cells (TCM) from CD4+ CD197+ CD45RA+ naive T cells (Tnaive). It also enables us to precisely quantify CD14+ monocytes (CV = 6.6 %). Our new “monocyte and T cell” (MoT) assay predicts immune-related hepatitis with a positive predictive value (PPV) of 83 % and negative predictive value (NPV) of 80 %. Our essential improvements open the possibility of sharing our predictive methods with other clinical centers. Furthermore, condensing measurements of monocyte and memory T cell subsets into a single assay simplifies our workflows and facilitates computational analyses.

T cell characteristics associated with toxicity to immune checkpoint blockade in patients with melanoma

Abstract: Severe immune-related adverse events (irAEs) occur in up to 60% of patients with melanoma treated with immune checkpoint inhibitors (ICIs). However, it is unknown whether a common baseline immunological state precedes irAE development. Here we applied mass cytometry by time of flight, single-cell RNA sequencing, single-cell V(D)J sequencing, bulk RNA sequencing and bulk T cell receptor (TCR) sequencing to study peripheral blood samples from patients with melanoma treated with anti-PD-1 monotherapy or anti-PD-1 and anti-CTLA-4 combination ICIs. By analyzing 93 pre- and early on-ICI blood samples and 3 patient cohorts (n = 27, 26 and 18), we found that 2 pretreatment factors in circulation-activated CD4 memory T cell abundance and TCR diversity-are associated with severe irAE development regardless of organ system involvement. We also explored on-treatment changes in TCR clonality among patients receiving combination therapy and linked our findings to the severity and timing of irAE onset. These results demonstrate circulating T cell characteristics associated with ICI-induced toxicity, with implications for improved diagnostics and clinical management.

CD4+ tumor infiltrating lymphocytes are prognostic and independent of R-IPI in patients with DLBCL receiving R-CHOP chemo-immunotherapy

Abstract: Free to read Despite the Revised International Prognostic Index's (R-IPI) undoubted utility in diffuse large B-cell lymphoma (DLBCL), significant clinical heterogeneity within R-IPI categories persists. Emerging evidence indicates that circulating host immunity is a robust and R-IPI independent prognosticator, most likely reflecting the immune status of the intratumoral microenvironment. We hypothesized that direct quantification of immunity within lymphomatous tissue would better permit stratification within R-IPI categories. We analyzed 122 newly diagnosed consecutive DLBCL patients treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) chemo-immunotherapy. Median follow-up was 4 years. As expected, the R-IPI was a significant predictor of outcome with 5-year overall survival (OS) 87% for very good, 87% for good, and 51% for poor-risk R-IPI scores (P < 0.001). Consistent with previous reports, systemic immunity also predicted outcome (86% OS for high lymphocyte to monocyte ratio [LMR], versus 63% with low LMR, P = 0.01). Multivariate analysis confirmed LMR as independently prognostic. Flow cytometry on fresh diagnostic lymphoma tissue, identified CD4+ T-cell infiltration as the most significant predictor of outcome with ≥23% infiltration dividing the cohort into high and low risk groups with regard to event-free survival (EFS, P = 0.007) and OS (P = 0.003). EFS and OS were independent of the R-IPI and LMR. Importantly, within very good/good R-IPI patients, CD4+ T-cells still distinguished patients with different 5 year OS (high 96% versus low 63%, P = 0.02). These results illustrate the importance of circulating and local intratumoral immunity in DLBCL treated with R-CHOP.

Toward a New Molecular Taxonomy of Diffuse Large B-cell Lymphoma.

Abstract: Diffuse large B-cell lymphoma (DLBCL) represents a grouping of clinically and biologically heterogeneous tumors Application of advanced molecular technology has significantly expanded our knowledge of DLBCL pathobiology, allowing identification of subgroups with common, potentially targetable, biological themes Here, we review the recent molecular analyses that could provide a paradigm shift to a new taxonomy, foundational to the rational transition to precision medicine We discuss how classification systems may be synthesized into a common taxonomy, drawing strength from the relationships between genetic alterations, gene expression, and tumor microenvironment Finally, challenges to translating such a taxonomy to the clinic will be outlined

The Tumor Microenvironment of DLBCL in the Computational Era.

Abstract: Among classical exemplifications of tumor microenvironment (TME) in lymphoma pathogenesis, the "effacement model" resembled by diffuse large B cell lymphoma (DLBCL) implies strong cell autonomous survival and paucity of non-malignant elements. Nonetheless, the magnitude of TME exploration is increasing as novel technologies allow the high-resolution discrimination of cellular and extra-cellular determinants at the functional, more than morphological, level. Results from genomic-scale studies and recent clinical trials revitalized the interest in this field, prompting the use of new tools to dissect DLBCL composition and reveal novel prognostic association. Here we revisited major controversies related to TME in DLBCL, focusing on the use of bioinformatics to mine transcriptomic data and provide new insights to be translated into the clinical setting.