T-cell-based Immunotherapies for Haematological Cancers, Part A: A SWOT Analysis of Immune Checkpoint Inhibitors (ICIs) and Bispecific T-Cell Engagers (BiTEs).

Haematology has been at the vanguard of cancer immunotherapy. Immune checkpoint inhibitors (ICIs), bispecific T-cell engagers (BiTEs), allogeneic haematopoietic stem cell transplantation (allo-HSCT) and donor lymphocyte infusion (DLI), as well as adoptive T-cell therapies outside the setting of allo-HSCT, have been approved for distinct haematologic malignancies producing durable responses in otherwise untreatable patients. Despite recent advances, immunotherapies do not benefit most patients, due to resistance or lack of response, and are only approved in specific settings. Moreover, immunotherapies are expensive and may produce severe immune related adverse reactions. Combination therapy complicates the picture and requires further evaluation. This review considers the current status and future perspectives of ICIs and BiTEs approved for haematological malignancies by analysing their strengths, weaknesses, opportunities and threats (SWOT). The biological rationale for anti-cancer mechanisms, clinical data for specific haematological cancers, efficacy, toxicity, response and resistance profiles, novel strategies to improve these characteristics as well as the potential targets to enhance or expand the application of ICIs and BiTEs are also discussed.

T-cell-based Immunotherapies for Haematological Cancers, Part B: A SWOT Analysis of Adoptive Cell Therapies.

Haematology has been at the forefront of cancer immunotherapy advancements. Allogeneic haematopoietic stem cell transplant (allo-HSCT) is one of the earliest forms of cancer immunotherapy and continues to cure thousands of patients. Donor lymphocyte infusion (DLI) increases allo-HSCT efficacy and reduces graft-versus-host disease (GVHD). In recent years, chimeric antigen receptor (CAR)-T-cells have been approved for the treatment of distinct haematologic malignancies, producing durable response in otherwise untreatable patients. New target antigen identification and technological advances have enabled the structural and functional evolution of CARs, broadening their applications. Despite successes, adoptive T-cell (ATC) therapies are expensive, can cause severe adverse reactions and their use is restricted to few patients. This review considers the current status and future perspectives of allogeneic transplant and donor lymphocytes, as well as novel ATC therapies, such as CAR-T-cells in haematological malignancies by analysing their strengths, weaknesses, opportunities, and threats (SWOT). The biological rationale for anti-cancer mechanisms and development; current clinical data in specific haematological malignancies; efficacy, toxicity, response and resistance profiles; novel strategies to improve these characteristics; and potential targets to enhance or expand the application of these therapies are discussed.

Retinoic acid-responsive CD8 effector T cells are selectively increased in IL-23-rich tissue in gastrointestinal GVHD.

Gastrointestinal (GI) graft-versus-host disease (GVHD) is a major barrier in allogeneic hematopoietic stem cell transplantation (allo-HSCT). The metabolite retinoic acid (RA) potentiates GI-GVHD in mice via alloreactive T cells expressing the RA receptor-α (RARα), but the role of RA-responsive cells in human GI-GVHD remains undefined. Therefore, we used conventional and novel sequential immunostaining and flow cytometry to scrutinize RA-responsive T cells in tissues and blood of patients who had received allo-HSCT and to characterize the impact of RA on human T-cell alloresponses. Expression of RARα by human mononuclear cells was increased after exposure to RA. RARαhi mononuclear cells were increased in GI-GVHD tissue, contained more cellular RA-binding proteins, localized with tissue damage, and correlated with GVHD severity and mortality. By using a targeted candidate protein approach, we predicted the phenotype of RA-responsive T cells in the context of increased microenvironmental interleukin-23 (IL-23). Sequential immunostaining confirmed the presence of a population of RARαhi CD8 T cells with the predicted phenotype that coexpressed the effector T-cell transcription factor T-bet and the IL-23-specific receptor (IL-23R). These cells were increased in GI- but not skin-GVHD tissues and were also selectively expanded in the blood of patients with GI-GVHD. Finally, functional approaches demonstrated that RA predominantly increased alloreactive GI-tropic RARαhi CD8 effector T cells, including cells with the phenotype identified in vivo. IL-23-rich conditions potentiated this effect by selectively increasing ß7 integrin expression on CD8 effector T cells and reducing CD4 T cells with a regulatory cell phenotype. In summary, we have identified a population of RA-responsive effector T cells with a distinctive phenotype that is selectively expanded in human GI-GVHD and that represents a potential new therapeutic target.

EAU-EANM-ESTRO-ESUR-SIOG Prostate Cancer Guideline Panel Consensus Statements for Deferred Treatment with Curative Intent for Localised Prostate Cancer from an International Collaborative Study (DETECTIVE Study).

BACKGROUND: There is uncertainty in deferred active treatment (DAT) programmes, regarding patient selection, follow-up and monitoring, reclassification, and which outcome measures should be prioritised. OBJECTIVE: To develop consensus statements for all domains of DAT. DESIGN, SETTING, AND PARTICIPANTS: A protocol-driven, three phase study was undertaken by the European Association of Urology (EAU)-European Association of Nuclear Medicine (EANM)-European Society for Radiotherapy and Oncology (ESTRO)-European Association of Urology Section of Urological Research (ESUR)-International Society of Geriatric Oncology (SIOG) Prostate Cancer Guideline Panel in conjunction with partner organisations, including the following: (1) a systematic review to describe heterogeneity across all domains; (2) a two-round Delphi survey involving a large, international panel of stakeholders, including healthcare practitioners (HCPs) and patients; and (3) a consensus group meeting attended by stakeholder group representatives. Robust methods regarding what constituted the consensus were strictly followed. RESULTS AND LIMITATIONS: A total of 109 HCPs and 16 patients completed both survey rounds. Of 129 statements in the survey, consensus was achieved in 66 (51%); the rest of the statements were discussed and voted on in the consensus meeting by 32 HCPs and three patients, where consensus was achieved in additional 27 statements (43%). Overall, 93 statements (72%) achieved consensus in the project. Some uncertainties remained regarding clinically important thresholds for disease extent on biopsy in low-risk disease, and the role of multiparametric magnetic resonance imaging in determining disease stage and aggressiveness as a criterion for inclusion and exclusion. CONCLUSIONS: Consensus statements and the findings are expected to guide and inform routine clinical practice and research, until higher levels of evidence emerge through prospective comparative studies and clinical trials. PATIENT SUMMARY: We undertook a project aimed at standardising the elements of practice in active surveillance programmes for early localised prostate cancer because currently there is great variation and uncertainty regarding how best to conduct them. The project involved large numbers of healthcare practitioners and patients using a survey and face-to-face meeting, in order to achieve agreement (ie, consensus) regarding best practice, which will provide guidance to clinicians and researchers.

Correction: Genomic profiling reveals spatial intra-tumor heterogeneity in follicular lymphoma.

In the original version of this article the authors noted an omission in the author affiliations where the university details: Queen Mary University of London was not included in the original affiliation for the majority of the authors. The correct affiliations are as follows1. Centre for Haemato-Oncology, Barts Cancer Institute, Queen Mary University of London, London, UK3. Centre for Molecular Oncology, Barts Cancer Institute, Queen Mary University of London, London, UK6. Evolution and Cancer Laboratory, Barts Cancer Institute, Queen Mary University of London, London, UK.

Infusion of Alloanergized Donor Lymphocytes after CD34-selected Haploidentical Myeloablative Hematopoietic Stem Cell Transplantation.

Purpose: Allogeneic hematopoietic stem-cell transplantation (HSCT) is a curative treatment for many hematologic cancers. Use of haploidentical (mismatched) donors increases HSCT availability but is limited by severe graft-versus-host disease (GvHD) and delayed immune reconstitution. Alloanergization of donor T cells is a simple approach to rebuild immunity while limiting GvHD after haploidentical HSCT, but the optimal T-cell dose and impact on immune reconstitution remain unknown.Patients and Methods: We performed a multicenter phase I trial of alloanergized donor lymphocyte infusion (aDLI) after CD34-selected myeloablative haploidentical HSCT. The primary aim was feasibility and safety with secondary aims of assessing the less frequently addressed issue of impact on immune reconstitution.Results: Nineteen patients with high-risk acute leukemia or myelodysplasia were enrolled. Engraftment occurred in 18 of 19 patients (95%). Pre-aDLI, 12 patients (63%) had bacteremia, nine of 17 at-risk patients (53%) reactivated CMV, and one developed acute GvHD. Sixteen patients received aDLI at dose levels 1 (103 T cells/kg, n = 4), 2 (104, n = 8), and 3 (105, n = 4). After aDLI, five patients developed clinically significant acute GvHD, and four of 14 at-risk patients (29%) reactivated CMV. T-cell recovery was significantly greater, and functional virus- and tumor-associated antigen-specific T cells were detectable earlier in patients receiving dose level 2 or 3 versus dose level 1/no aDLI. Alloanergization of donor cells expanded the CD4+ T-regulatory cell frequency within aDLI, which increased further in vivo without impeding expansion of virus- and tumor-associated antigen-specific T cells.Conclusions: These data demonstrate safety and a potential role for aDLI in contributing to immune reconstitution and expanding tolerogenic regulatory T cells in vivo after CD34-selected myeloablative haploidentical HSCT. Clin Cancer Res; 24(17); 4098-109. ©2018 AACR.

Durable graft-versus-leukaemia effects without donor lymphocyte infusions - results of a phase II study of sequential T-replete allogeneic transplantation for high-risk acute myeloid leukaemia and myelodysplasia.

Allogeneic haematopoietic stem-cell transplantation remains the only curative treatment for relapsed/refractory acute myeloid leukaemia (AML) and high-risk myelodysplasia but has previously been limited to patients who achieve remission before transplant. New sequential approaches employing T-cell depleted transplantation directly after chemotherapy show promise but are burdened by viral infection and require donor lymphocyte infusions (DLI) to augment donor chimerism and graft-versus-leukaemia effects. T-replete transplantation in sequential approaches could reduce both viral infection and DLI usage. We therefore performed a single-arm prospective Phase II clinical trial of sequential chemotherapy and T-replete transplantation using reduced-intensity conditioning without planned DLI. The primary endpoint was overall survival. Forty-seven patients with relapsed/refractory AML or high-risk myelodysplasia were enrolled; 43 proceeded to transplantation. High levels of donor chimerism were achieved spontaneously with no DLI. Overall survival of transplanted patients was 45% and 33% at 1 and 3 years. Only one patient developed cytomegalovirus disease. Cumulative incidences of treatment-related mortality and relapse were 35% and 20% at 1 year. Patients with relapsed AML and myelodysplasia had the most favourable outcomes. Late-onset graft-versus-host disease protected against relapse. In conclusion, a T-replete sequential transplantation using reduced-intensity conditioning is feasible for relapsed/refractory AML and myelodysplasia and can deliver graft-versus-leukaemia effects without DLI.

Does Chronic Tinnitus Alter the Emotional Response Function of the Amygdala?: A Sound-Evoked fMRI Study.

Tinnitus is often associated with strong negative thoughts and emotions which can contribute to a distressing and chronic long-term condition. The amygdala, the "feeling and reacting" part of the brain, may play a key role in this process. Although implicated in several theoretical models of tinnitus, quantification of activity in the human amygdala has only been made possible more recently through neuroimaging methods such as functional magnetic resonance imaging (fMRI) but benefits from modified scanning parameters using a double-echo acquisition for improved BOLD sensitivity. This study thus examined the role of the amygdala in emotional sound processing in people with tinnitus using a novel double-echo imaging sequence for optimal detectability of subcortical activity. Our hypotheses were: (1) emotionally evocative sound clips rated as pleasant or unpleasant would elicit stronger amygdalar activation than sound clips rated as neutral, (2) people with tinnitus have greater amygdalar activation in response to emotionally evocative sounds (relative to neutral sounds) compared to controls. Methods: Twelve participants all with chronic, constant tinnitus took part. We also recruited 11 age and hearing-matched controls. Participants listened to a range of emotionally evocative sound clips; rated as pleasant, unpleasant or neutral. A region-of-interest analysis was chosen to test our a priori hypotheses. Results: Both groups displayed a robust and similar overall response to sounds vs. silence in the following ascending auditory pathways; inferior colliculus, medial geniculate body and the primary auditory cortex. In support of our first hypothesis, the amygdala's response to pleasant and unpleasant sound clips was significantly greater than neutral sounds. Opposing our second hypothesis, we found that the amygdala's overall response to pleasant and unpleasant sounds (compared to neutral sounds) was actually lower in the tinnitus group as compared to the controls. Conclusions: The "muted" amygdala activation observed in the tinnitus group could reflect an internal modification of emotional response perhaps as a result of successful habituation to emotionally negative sound. This interpretation would predict a heightened amygdala emotional response in individuals with a more clinically bothersome tinnitus.

Pre-market version of a commercially available hearing instrument with a tinnitus sound generator: feasibility of evaluation in a clinical trial.

OBJECTIVE: This report considers feasibility of conducting a UK trial of combination devices for tinnitus, using data from the study which evaluated different listener programmes available within the pre-market version of Oticon Alta with Tinnitus Sound Generator. DESIGN: Open and closed questions addressed the following feasibility issues: (1) Participant recruitment; (2) Device acceptability; (3) Programme preferences in different self-nominated listening situations; (4) Usability; (5) Compliance; (6) Adverse events. STUDY SAMPLE: Eight current combination hearing aid users (all males) aged between 62-72 years (mean age 67.25 years, SD = 3.8). RESULTS: All eight participants reported the physical aspects and noise options on the experimental device to be acceptable. Programmes with amplification and masking features were equally preferred over the basic amplification-only programme. Individual preferences for the different programme options varied widely, both across participants and across listening situations. CONCLUSIONS: A set of recommendations for future trials were formulated which calls for more "real world" trial design rather than tightly controlling the fitting procedure.

Neuroanatomical Alterations in Tinnitus Assessed with Magnetic Resonance Imaging.

Previous studies of anatomical changes associated with tinnitus have provided inconsistent results, with some showing significant cortical and subcortical changes, while others have found effects due to hearing loss, but not tinnitus. In this study, we examined changes in brain anatomy associated with tinnitus using anatomical scans from 128 participants with tinnitus and hearing loss, tinnitus with clinically normal hearing, and non-tinnitus controls with clinically normal hearing. The groups were matched for hearing loss, age and gender. We employed voxel- and surface-based morphometry (SBM) to investigate gray and white matter volume and thickness within regions-of-interest (ROI) that were based on the results of previous studies. The largest overall effects were found for age, gender, and hearing loss. With regard to tinnitus, analysis of ROI revealed numerous small increases and decreases in gray matter and thickness between tinnitus and non-tinnitus controls, in both cortical and subcortical structures. For whole brain analysis, the main tinnitus-related significant clusters were found outside sensory auditory structures. These include a decrease in cortical thickness for the tinnitus group compared to controls in the left superior frontal gyrus (SFG), and a decrease in cortical volume with hearing loss in left Heschl's gyrus (HG). For masked analysis, we found a decrease in gray matter volume in the right Heschle's gyrus for the tinnitus group compared to the controls. We found no changes in the subcallosal region as reported in some previous studies. Overall, while some of the morphological differences observed in this study are similar to previously published findings, others are entirely different or even contradict previous results. We highlight other discrepancies among previous results and the increasing need for a more precise subtyping of the condition.

Allospecific Tregs Expanded After Anergization Remain Suppressive in Inflammatory Conditions but Lack Expression of Gut-homing Molecules.

Cell therapy with antigen-specific regulatory T-cells (Treg) has great potential to selectively control unwanted immune responses after allogeneic stem-cell or solid organ transplantation and in autoimmune diseases. Ex vivo allostimulation with costimulatory blockade (alloanergization) of human T-cells expands populations of alloantigen-specific Treg, providing a cellular strategy to control donor T-cell alloresponses causing graft-versus-host disease after allogeneic hematopoietic stem-cell transplantation. Crucially, it is not known if Treg expanded in this way are stable in proinflammatory conditions encountered after transplantation, or if they possess capacity to migrate to key target organs. Using an in vitro model to functionally characterize human Treg expanded after alloanergization, we now show that these cells remain potently allosuppressive in the presence of relevant exogenous inflammatory signals. Expanded allospecific Treg retained expression of molecules conferring migratory capacity to several organs but small intestine-specific chemotaxis was markedly impaired, in keeping with the preponderance of gut graft-versus-host disease in previous clinical studies using this strategy. Importantly, impaired gut-specific chemotaxis could be partially corrected by pharmacological treatment. These findings will facilitate more effective application of this cellular approach to limit T-cell alloresponses after hematopoietic stem-cell transplantation and the wider application of the strategy to other clinical settings.

Acute myeloid leukemia does not deplete normal hematopoietic stem cells but induces cytopenias by impeding their differentiation.

Acute myeloid leukemia (AML) induces bone marrow (BM) failure in patients, predisposing them to life-threatening infections and bleeding. The mechanism by which AML mediates this complication is unknown but one widely accepted explanation is that AML depletes the BM of hematopoietic stem cells (HSCs) through displacement. We sought to investigate how AML affects hematopoiesis by quantifying residual normal hematopoietic subpopulations in the BM of immunodeficient mice transplanted with human AML cells with a range of genetic lesions. The numbers of normal mouse HSCs were preserved whereas normal progenitors and other downstream hematopoietic cells were reduced following transplantation of primary AMLs, findings consistent with a differentiation block at the HSC-progenitor transition, rather than displacement. Once removed from the leukemic environment, residual normal hematopoietic cells differentiated normally and outcompeted steady-state hematopoietic cells, indicating that this effect is reversible. We confirmed the clinical significance of this by ex vivo analysis of normal hematopoietic subpopulations from BM of 16 patients with AML. This analysis demonstrated that the numbers of normal CD34(+)CD38(-) stem-progenitor cells were similar in the BM of AML patients and controls, whereas normal CD34(+)CD38(+) progenitors were reduced. Residual normal CD34(+) cells from patients with AML were enriched in long-term culture, initiating cells and repopulating cells compared with controls. In conclusion the data do not support the idea that BM failure in AML is due to HSC depletion. Rather, AML inhibits production of downstream hematopoietic cells by impeding differentiation at the HSC-progenitor transition.

Long-term survival with low toxicity after allogeneic transplantation for acute myeloid leukaemia and myelodysplasia using non-myeloablative conditioning without T cell depletion.

The toxicity burden and long-term anti-leukaemic effect of non-myeloablative (NMA) allogeneic haematopoietic stem-cell transplantation (AHSCT) for acute myeloid leukaemia (AML) and myelodysplasia (MDS) remains undefined. We report the outcome of 56 patients with AML/MDS transplanted from human leucocyte antigen-matched donors using NMA conditioning without T-cell depletion. With a median follow-up of 5 years, treatment-related mortality was 9% and current disease-free survival (CDFS) was 45% (overall) and 55% (patients transplanted in remission). Development of graft-versus-host disease upon withdrawal of post-transplant immunosuppression was associated with less relapse and better CDFS. These data confirm that NMA AHSCT without T-cell depletion is safe and can result in sustained remissions of AML/MDS.

New ways to separate graft-versus-host disease and graft-versus-tumour effects after allogeneic haematopoietic stem cell transplantation.

A major challenge to transplant immunologists and physicians remains the separation of harmful graft-versus-host disease (GvHD) and beneficial graft-versus-tumour (GvT) effects after allogeneic haematopoietic stem cell transplantation. Recent advances in our understanding of the allogeneic immune response provide potential new opportunities to achieve this goal. Three potential new approaches that capitalize on this new knowledge are considered in depth; the manipulation of organ-specific cytokines and other pro-inflammatory signals, the selective manipulation of donor effector T cell migration, and the development of cell-mediated immunosuppressive strategies using donor-derived regulatory T cells. These new approaches could provide strategies for local control of allogeneic immune responses, a new paradigm to separate GvHD and GvT effects. Although these strategies are currently in their infancy and have challenges to successful translation to clinical practice, all have exciting potential for the future.

Ex vivo alloanergization with belatacept: a strategy to selectively modulate alloresponses after transplantation.

Ex vivo alloanergization of human immune cells, via allostimulation in the presence of costimulatory blockade with either a combination of anti-B7.1 and anti-B7.2 antibodies or first-generation cytotoxic T-lymphocyte antigen 4-immunoglobulin (CTLA4-Ig), induces alloantigen-specific hyporesponsiveness and expands alloantigen-specific regulatory T cells (Treg). We have successfully used this approach in the clinical setting of haploidentical hematopoietic stem cell transplantation. Recently, the in vivo use of a new second-generation CTLA4-Ig, belatacept, has shown promise in controlling alloresponses after transplantation of both human kidneys and islet cells. We therefore compared the efficiency of first- and second-generation CTLA4-Ig in alloanergizing human peripheral blood mononuclear cells (PBMCs) and investigated whether ex vivo alloanergization with belatacept could be used to engineer an alloantigen-specific immunoregulatory population of autologous cells suitable for administration to recipients of cellular or solid organ transplant recipients. Alloanergization of HLA-mismatched human PBMCs with belatacept resulted in a greater reduction in subsequent alloresponses than alloanergization with first generation CTLA4-Ig. Moreover, subsequent ex vivo re-exposure of alloanergized cells to alloantigen in the absence of belatacept resulted in a significant expansion of Tregs with enhanced alloantigen-specific suppressive function. Alloanergized PBMCs retained functional Epstein-Barr virus (EBV)-specific T-cell responses, and expanded Tregs did not suppress EBV-specific proliferation of autologous cells. These results suggest that ex vivo alloanergization with belatacept provides a platform to engineer populations of recipient Treg with specificity for donor alloantigens but without nonspecific suppressive capacity. The potential advantages of such cells for solid organ transplantation include (1) reduction of the need for nonspecific immunosuppression, (2) retention of pathogen-specific immunity, and (3) control of graft rejection, if used as an intervention.

T-cell replete fludarabine/cyclophosphamide reduced intensity allogeneic stem cell transplantation for lymphoid malignancies.

The relative merits of reduced-intensity allogeneic stem cell transplantation (RISCT) for high-risk indolent lymphoid malignancies are emerging, although the preferred conditioning regimen to manage the risks of graft-versus-host disease (GVHD) is not clearly defined. Here we report the outcome of 73 patients with lymphoid malignancies who received RISCT with a fludarabine/cyclophosphosphamide conditioning regimen and a median follow-up of 3 years. Median age was 54 years. Forty-eight per cent of patients had previously undergone autologous stem cell transplantation with a median of three prior therapies. Non-relapse mortality at 3 years was 19% but only 5% for patients with multiple myeloma (MM). Three-year overall survival and current progression-free survival was 67% and 63% respectively. Grade 2-4 acute GVHD occurred in 14% of patients while 49% had chronic GVHD requiring systemic immunosuppression. The preparatory regimen in this study has the advantage of reduced acute GVHD and low mortality, notably in patients with MM. In addition, this strategy provides long-term disease control in a significant proportion of patients with particular benefit in those with high-risk follicular lymphoma.