Dendritic cells as cancer therapeutics.

The ability of immune therapies to control cancer has recently generated intense interest. This therapeutic outcome is reliant on T cell recognition of tumour cells. The natural function of dendritic cells (DC) is to generate adaptive responses, by presenting antigen to T cells, hence they are a logical target to generate specific anti-tumour immunity. Our understanding of the biology of DC is expanding, and they are now known to be a family of related subsets with variable features and function. Most clinical experience to date with DC vaccination has been using monocyte-derived DC vaccines. There is now growing experience with alternative blood-derived DC derived vaccines, as well as with multiple forms of tumour antigen and its loading, a wide range of adjuvants and different modes of vaccine delivery. Key insights from pre-clinical studies, and lessons learned from early clinical testing drive progress towards improved vaccines. The potential to fortify responses with other modalities of immunotherapy makes clinically effective "second generation" DC vaccination strategies a priority for cancer immune therapists.

Survival outcomes of patients with diffuse large B-cell lymphoma undergoing autologous stem cell transplantation in Germany: real-world evidence from an administrative database between 2010 and 2019.

Background: Limited real-world evidence is available for patients with diffuse large B-cell lymphoma (DLBCL) who received an autologous stem cell transplantation (ASCT) in Germany. Objectives: This study aims to describe the real-world survival outcomes of patients with DLBCL who received ASCT in Germany after diagnosis. Design: This study is a retrospective database analysis covering the period between 2010 and 2019. Methods: Unadjusted overall survival (OS) was plotted using the Kaplan-Meier estimator for the overall population and stratified by relapse status. A Cox regression was run to identify factors that influence OS. Results: A total of 112 patients received an ASCT, with the average time from first-line treatment to ASCT being 11.7 months. The median OS estimated by Kaplan-Meier was 83.4 months for the entire cohort. The only variable that significantly reduced the OS was the presence of subsequent treatment after ASCT in a time-dependent model. Conclusion: OS after ASCT for DLBCL patients in Germany is higher than previously reported and may still be considered a valid option for carefully selected patients with relapsed/refractory DLBCL.

Healthcare Resource Utilization and Associated Costs of German Patients with Diffuse Large B-Cell Lymphoma: A Retrospective Health Claims Data Analysis.

INTRODUCTION: Diffuse large B-cell lymphoma (DLBCL) is the most common form of non-Hodgkin's lymphoma with increasing prevalence. Although the disease burden associated with DLBCL is high, only limited data on healthcare resource utilization (HCRU) and associated costs of German patients with DLBCL is available. METHODS: Using a large claims database of the German statutory health insurance with 6.7 million enrollees, we identified patients who were newly diagnosed with DLBCL between 2011 and 2018 (index date). Treatment lines were identified based on a predefined set of medication. HCRU and related costs were collected for the entire post index period and per treatment line. RESULTS: A total of 2495 incident DLBCL patients were eligible for the analysis. The average follow-up time after index was 41.7 months. During follow-up, 1991 patients started a first-line treatment, 868 a second-line treatment, and 354 a third-line treatment. Overall, patients spent on average (SD) 5.24 (6.17) days per month in hospital after index. While on anti-cancer treatment, this number increased to nine (10.9) in first-line, 8.7 (13.7) in second-line, and 9.4 (15.8) in third-line treatments. Overall costs per patient per month (PPPM) increased from €421 (875.70) before to €3695 (4652) after index. While on a treatment line, PPPM costs were €17,170 (10,246) in first-line, €13,362 (12,685) in second-line, and €12,112 (16,173) in third-line treatments. Time-unadjusted absolute costs sum up to €59,868 (43,331), €35,870 (37,387), and €28,832 (40,540) during first-line, second-line, and third-line treatments, respectively. The main cost drivers were hospitalizations (71% of total costs) and drug acquisition costs (18% of total costs). CONCLUSIONS: The financial burden of DLBCL in Germany is high, mainly due to hospitalization and drug costs. Therefore, there is a high medical need for new cost-effective therapeutic options that can lower the disease burden and remain financially viable to support the growing number of patients with this aggressive disease.

Survival outcomes of patients newly diagnosed with diffuse large B-cell lymphoma: real-world evidence from a German claims database.

PURPOSE: Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin lymphoma with increasing incidence. Although the burden of disease is high, only limited current real-world data on survival analysis, especially survival time, of German patients with DLBCL are available. This retrospective claims-based analysis was conducted to describe real-world survival evidence and treatment patterns of patients with DLBCL in Germany. METHODS: Using a large claims database of the German statutory health insurance with 6.7 million enrollees, we identified patients between 2010 and 2019 who were newly diagnosed with DLBCL (index date) and had no other cancer co-morbidity. Overall survival (OS) from index date and from the end of each treatment line was plotted by means of the Kaplan-Meier estimator, both for the overall cohort and stratified by treatment regimen. Treatment lines were identified based on a predefined set of medications categorized by established DLBCL treatment recommendations. RESULTS: 2495 incident DLBCL patients were eligible for the study. After index date, 1991 patients started a first-line, 868 a second-line, and 354 a third-line therapy. In first line, 79.5% of patients received a Rituximab-based therapy. 5.0% of the of the 2495 patients received a stem cell transplantation. Overall, median OS after index was 96.0 months. CONCLUSION: DLBCL-associated mortality is still high, especially in relapsed patients and in the elderly. Therefore, there is a high medical need for new effective treatments that can improve survival outcomes in DLBCL patients.

Distinguishing human peripheral blood CD16+ myeloid cells based on phenotypic characteristics.

Myeloid lineage cells present in human peripheral blood include dendritic cells (DC) and monocytes. The DC are identified phenotypically as HLA-DR+ cells that lack major cell surface lineage markers for T cells (CD3), B cells (CD19, CD20), NK cells (CD56), red blood cells (CD235a), hematopoietic stem cells (CD34), and Mo that express CD14. Both DC and Mo can be phenotypically divided into subsets. DC are divided into plasmacytoid DC, which are CD11c- , CD304+ , CD85g+ , and myeloid DC that are CD11c+ . The CD11c+ DC are readily classified as CD1c+ DC and CD141+ DC. Monocytes are broadly divided into the CD14+ CD16- (classical) and CD14dim CD16+ subsets (nonclassical). A population of myeloid-derived cells that have DC characteristics, that is, HLA-DR+ and lacking lineage markers including CD14, but express CD16 are generally clustered with CD14dim CD16+ monocytes. We used high-dimensional clustering analyses of fluorescence and mass cytometry data, to delineate CD14+ monocytes, CD14dim CD16+ monocytes (CD16+ Mo), and CD14- CD16+ DC (CD16+ DC). We sought to identify the functional and kinetic relationship of CD16+ DC to CD16+ Mo. We demonstrate that differentiation of CD16+ DC and CD16+ Mo during activation with IFNγ in vitro and as a result of an allo-hematopoietic cell transplant (HCT) in vivo resulted in distinct populations. Recovery of blood CD16+ DC in both auto- and allo-(HCT) patients after myeloablative conditioning showed similar reconstitution and activation kinetics to CD16+ Mo. Finally, we show that expression of the cell surface markers CD300c, CCR5, and CLEC5a can distinguish the cell populations phenotypically paving the way for functional differentiation as new reagents become available.

A blood dendritic cell vaccine for acute myeloid leukemia expands anti-tumor T cell responses at remission.

Only modest advances in AML therapy have occurred in the past decade and relapse due to residual disease remains the major challenge. The potential of the immune system to address this is evident in the success of allogeneic transplantation, however this leads to considerable morbidity. Dendritic cell (DC) vaccination can generate leukemia-specific autologous immunity with little toxicity. Promising results have been achieved with vaccines developed in vitro from purified monocytes (Mo-DC). We now demonstrate that blood DC (BDC) have superior function to Mo-DC. Whilst BDC are reduced at diagnosis in AML, they recover following chemotherapy and allogeneic transplantation, can be purified using CMRF-56 antibody technology, and can stimulate functional T cell responses. While most AML patients in remission had a relatively normal T cell landscape, those who had received fludarabine as salvage therapy have persistent T cell abnormalities including reduced number, altered subset distribution, failure to expand, and increased activation-induced cell death. Furthermore, PD-1 and TIM-3 are increased on CD4T cells in AML patients in remission and their blockade enhances the expansion of leukemia-specific T cells. This confirms the feasibility of a BDC vaccine to consolidate remission in AML and suggests it should be tested in conjunction with checkpoint blockade.

CMRF-56(+) blood dendritic cells loaded with mRNA induce effective antigen-specific cytotoxic T-lymphocyte responses.

There are numerous transcriptional, proteomic and functional differences between monocyte-derived dendritic cells (Mo-DC) and primary blood dendritic cells (BDC). The CMRF-56 monoclonal antibody (mAb) recognizes a cell surface marker, which is upregulated on BDC following overnight culture. Given its unique ability to select a heterogeneous population of BDC, we engineered a human chimeric (h)CMRF-56 IgG4 mAb to isolate primary BDC for potential therapeutic vaccination. The ability to select multiple primary BDC subsets from patients and load them with in vitro transcribed (IVT) mRNA encoding tumor antigen might circumvent the issues limiting the efficacy of Mo-DC. After optimizing and validating the purification of hCMRF-56(+) BDC, we showed that transfection of hCMRF-56(+) BDC with mRNA resulted in efficient mRNA translation and antigen presentation by myeloid BDC subsets, while preserving superior DC functions compared to Mo-DC. Immune selected and transfected hCMRF-56(+) BDC migrated very efficiently in vitro and as effectively as cytokine matured Mo-DC in vivo. Compared to Mo-DC, hCMRF-56(+) BDC transfected with influenza matrix protein M1 displayed superior MHC peptide presentation and generated potent antigen specific CD8(+) T-cell recall responses, while Wilms tumor 1 (WT1) transfected CMRF-56(+) BDC generated effective primary autologous cytotoxic T-cell responses. The ability of the combined DC subsets within hCMRF-56(+) BDC to present mRNA delivered tumor antigens merits phase I evaluation as a reproducible generic platform for the next generation of active DC immune therapies.

Adherence and motility characteristics of clinical Acinetobacter baumannii isolates.

Acinetobacter baumannii continues to be a major health problem especially in hospital settings. Herein, features that may play a role in persistence and disease potential were investigated in a collection of clinical A. baumannii strains from Australia. Twitching motility was found to be a common trait in A. baumannii international clone I strains and in abundant biofilm formers, whereas swarming motility was only observed in isolates not classified within the international clone lineages. Bioinformatic analysis of the type IV fimbriae revealed a correlation between PilA sequence homology and motility. A high level of variability in adherence to both abiotic surfaces and epithelial cells was found. We report for the first time the motility characteristics of a large number of A. baumannii isolates and present a direct comparison of A. baumannii binding to nasopharyngeal and lung epithelial cells.