Single-cell multiomic dissection of response and resistance to chimeric antigen receptor T cells against BCMA in relapsed multiple myeloma.

Markers that predict response and resistance to chimeric antigen receptor (CAR) T cells in relapsed/refractory multiple myeloma are currently missing. We subjected mononuclear cells isolated from peripheral blood and bone marrow before and after the application of approved B cell maturation antigen-directed CAR T cells to single-cell multiomic analyses to identify markers associated with resistance and early relapse. Differences between responders and nonresponders were identified at the time of leukapheresis. Nonresponders showed an immunosuppressive microenvironment characterized by increased numbers of monocytes expressing the immune checkpoint molecule CD39 and suppressed CD8+ T cell and natural killer cell function. Analysis of CAR T cells showed cytotoxic and exhausted phenotypes in hyperexpanded clones compared to low/intermediate expanded clones. We identified potential immunotherapy targets on CAR T cells, like PD1, to improve their functionality and durability. Our work provides evidence that an immunosuppressive microenvironment causes resistance to CAR T cell therapies in multiple myeloma.

Phase to phase: Navigating drug combinations with hypomethylating agents in higher-risk MDS trials for optimal outcomes.

Recent developments in high-risk Myelodysplastic Neoplasms (HR MDS) treatment are confronted with challenges in study design due to evolving drug combinations with Hypomethylating Agents (HMAs). The shift from the International Prognostic Scoring System (IPSS) to its molecular revision (IPSS-M) has notably influenced research and clinical practice. Introducing concepts like the MDS/AML overlap complicate classifications and including chronic myelomonocytic leukemia (CMML) in MDS studies introduces another layer of complexity. The International Consortium for MDS emphasizes aligning HR MDS criteria with the 2022 ELN criteria for AML. Differences in advancements between AML and MDS treatments and hematological toxicity in HR MDS underline the importance of detailed trial designs. Effective therapeutic strategies require accurate reporting of adverse events, highlighting the need for clarity in criteria like the Common Terminology Criteria for Adverse Events (CTCAE). We provide an overview on negative clinical trials in HR MDS, analyze possible reasons and explore possibilities to optimize future clinical trials in this challenging patient population.

Cellular dynamics following CAR T cell therapy are associated with response and toxicity in relapsed/refractory myeloma.

B-cell maturation antigen (BCMA)-targeting chimeric antigen receptor (CAR) T cells revolutionized the treatment of relapsed/refractory multiple myeloma (RRMM). However, data on cellular (CAR) T cell dynamics and the association with response, resistance or the occurrence of cytokine release syndrome (CRS) are limited. Therefore, we performed a comprehensive flow cytometry analysis of 27 RRMM patients treated with Idecabtagene vicleucel (Ide-cel) to assess the expansion capacity, persistence and effects on bystander cells of BCMA-targeting CAR T cells. Additionally, we addressed side effects, like cytokine release syndrome (CRS) and cytopenia. Our results show that in vivo expansion of CD8+ CAR T cells is correlated to response, however persistence is not essential for durable remission in RRMM patients. In addition, our data provide evidence, that an increased fraction of CD8+ T cells at day of leukapheresis in combination with successful lymphodepletion positively influence the outcome. We show that patients at risk for higher-grade CRS can be identified already prior to lymphodepletion. Our extensive characterization contributes to a better understanding of the dynamics and effects of BCMA-targeting CAR T cells, in order to predict the response of individual patients as well as side effects, which can be counteracted at an early stage or even prevented.

Activation of distinct inflammatory pathways in subgroups of LR-MDS.

Aberrant innate immune signaling has been identified as a potential key driver of the complex pathophysiology of myelodysplastic neoplasms (MDS). This study of a large, clinically and genetically well-characterized cohort of treatment-naïve MDS patients confirms intrinsic activation of inflammatory pathways in general mediated by caspase-1, interleukin (IL)-1ß and IL-18 in low-risk (LR)-MDS bone marrow and reveals a previously unrecognized heterogeneity of inflammation between genetically defined LR-MDS subgroups. Principal component analysis resolved two LR-MDS phenotypes with low (cluster 1) and high (cluster 2) levels of IL1B gene expression, respectively. Cluster 1 contained 14/17 SF3B1-mutated cases, while cluster 2 contained 8/8 del(5q) cases. Targeted gene expression analysis of sorted cell populations showed that the majority of the inflammasome-related genes, including IL1B, were primarily expressed in the monocyte compartment, consistent with a dominant role in determining the inflammatory bone marrow environment. However, the highest levels of IL18 expression were found in hematopoietic stem and progenitor cells (HSPCs). The colony forming activity of healthy donor HSPCs exposed to monocytes from LR-MDS was increased by the IL-1ß-neutralizing antibody canakinumab. This work reveals distinct inflammatory profiles in LR-MDS that are of likely relevance to the personalization of emerging anti-inflammatory therapies.

Vitamin B5 and succinyl-CoA improve ineffective erythropoiesis in SF3B1-mutated myelodysplasia.

Patients with myelodysplastic syndrome and ring sideroblasts (MDS-RS) present with symptomatic anemia due to ineffective erythropoiesis that impedes their quality of life and increases morbidity. More than 80% of patients with MDS-RS harbor splicing factor 3B subunit 1 (SF3B1) mutations, the founder aberration driving MDS-RS disease. Here, we report how mis-splicing of coenzyme A synthase (COASY), induced by mutations in SF3B1, affects heme biosynthesis and erythropoiesis. Our data revealed that COASY was up-regulated during normal erythroid differentiation, and its silencing prevented the formation of erythroid colonies, impeded erythroid differentiation, and precluded heme accumulation. In patients with MDS-RS, loss of protein due to COASY mis-splicing led to depletion of both CoA and succinyl-CoA. Supplementation with COASY substrate (vitamin B5) rescued CoA and succinyl-CoA concentrations in SF3B1mut cells and mended erythropoiesis differentiation defects in MDS-RS primary patient cells. Our findings reveal a key role of the COASY pathway in erythroid maturation and identify upstream and downstream metabolites of COASY as a potential treatment for anemia in patients with MDS-RS.

A digital twin model for evidence-based clinical decision support in multiple myeloma treatment.

The treatment landscape for multiple myeloma (MM) has experienced substantial progress over the last decade. Despite the efficacy of new substances, patient responses tend to still be highly unpredictable. With increasing cognitive burden that is introduced through a complex and evolving treatment landscape, data-driven assistance tools are becoming more and more popular. Model-based approaches, such as digital twins (DT), enable simulation of probable responses to a set of input parameters based on retrospective observations. In the context of treatment decision-support, those mechanisms serve the goal to predict therapeutic outcomes to distinguish a favorable option from a potential failure. In the present work, we propose a similarity-based multiple myeloma digital twin (MMDT) that emphasizes explainability and interpretability in treatment outcome evaluation. We've conducted a requirement specification process using scientific literature from the medical and methodological domains to derive an architectural blueprint for the design and implementation of the MMDT. In a subsequent stage, we've implemented a four-layer concept where for each layer, we describe the utilized implementation procedure and interfaces to the surrounding DT environment. We further specify our solutions regarding the adoption of multi-line treatment strategies, the integration of external evidence and knowledge, as well as mechanisms to enable transparency in the data processing logic. Furthermore, we define an initial evaluation scenario in the context of patient characterization and treatment outcome simulation as an exemplary use case for our MMDT. Our derived MMDT instance is defined by 475 unique entities connected through 438 edges to form a MM knowledge graph. Using the MMRF CoMMpass real-world evidence database and a sample MM case, we processed a complete outcome assessment. The output shows a valid selection of potential treatment strategies for the integrated medical case and highlights the potential of the MMDT to be used for such applications. DT models face significant challenges in development, including availability of clinical data to algorithmically derive clinical decision support, as well as trustworthiness of the evaluated treatment options. We propose a collaborative approach that mitigates the regulatory and ethical concerns that are broadly discussed when automated decision-making tools are to be included into clinical routine.

Clonal hematopoiesis and cardiovascular disease: deciphering interconnections.

Cardiovascular and oncological diseases represent the global major causes of death. For both, a novel and far-reaching risk factor has been identified: clonal hematopoiesis (CH). CH is defined as clonal expansion of peripheral blood cells on the basis of somatic mutations, without overt hematological malignancy. The most commonly affected genes are TET2, DNMT3A, ASXL1 and JAK2. By the age of 70, at least 20-50% of all individuals carry a CH clone, conveying a striking clinical impact by increasing all-cause mortality by 40%. This is due predominantly to a nearly two-fold increase of cardiovascular risk, but also to an elevated risk of malignant transformation. Individuals with CH show not only increased risk for, but also worse outcomes after arteriosclerotic events, such as stroke or myocardial infarction, decompensated heart failure and cardiogenic shock. Elevated cytokine levels, dysfunctional macrophage activity and activation of the inflammasome suggest that a vicious cycle of chronic inflammation and clonal expansion represents the major functional link. Despite the apparently high impact of this entity, awareness, functional understanding and especially clinical implications still require further research. This review provides an overview of the current knowledge of CH and its relation to cardiovascular and hematological diseases. It focuses on the basic functional mechanisms in the interplay between atherosclerosis, inflammation and CH, identifies issues for further research and considers potential clinical implications.

Prospective validation of a biomarker-driven response prediction model to romiplostim in lower-risk myelodysplastic neoplasms - results of the EUROPE trial by EMSCO.

The EUROPE phase 2 trial investigated the predictive value of biomarkers on the clinical efficacy of single agent romiplostim (ROM) treatment in patients with lower-risk myelodysplastic neoplasms (LR-MDS) and thrombocytopenia within the 'European Myelodysplastic Neoplasms Cooperative Group' (EMSCO) network. A total of 77 patients with LR-MDS and a median platelet count of 25/nl were included, all patients received ROM at a starting dose of 750 µg by SC injection weekly. Thirty-two patients (42%) achieved a hematologic improvement of platelets (HI-P) with a median duration of 340 days. Neutrophil (HI-N) and erythroid (HI-E) responses were observed in three (4%) and seven (9%) patients, respectively. We could not confirm previous reports that HI-P correlated with baseline endogenous thrombopoietin levels and platelet transfusion history, but SRSF2 mutation status and hemoglobin levels at baseline were significantly linked to HI-P. Sequential analysis of variant allelic frequency of mutations like SRSF2 did not reveal an impact of ROM on clonal evolution in both responders and non-responders. In summary, our study confirms the safety and efficacy of ROM in LR-MDS patients and may allow to better define subgroups of patients with a high likelihood of response.

Case Report: Personalized Therapeutical Approaches with Lenalidomide in Del(5q): A Case Series.

Myelodysplastic Syndrome (MDS) with del(5q) represents a unique WHO entity, which is often treated with lenalidomide according to standard clinical practice. Guidelines concerning treatment duration have thus far not been implemented, but rather comprise an indefinite therapy until loss of response. This review presents three red blood cell (RBC) transfusion-dependent MDS with del(5q) cases, starting with one rare case with an unbalanced translocation t(2;5), involving the breakpoint of del(5q) and loss of the 5q15-5q31 region. To the best of our knowledge, no comparable case has been described before with a response to lenalidomide. Strikingly, treatment-induced and maintained cytogenetic complete remission (cCR) in this patient. Furthermore, we report two cases of classical del(5q), in which lenalidomide was interrupted after a short period of lenalidomide therapy at the time cCR was achieved. Despite drug holiday cCR was maintained for seven and nine years, respectively. Then del(5q) re-emerged in the absence of novel molecular aberrations and re-treatment with lenalidomide could again achieve cCR in both cases. Together, this series presents three cases of personalized therapy of MDS with del(5q).

Myelodysplastic syndromes: Biological and therapeutic consequences of the evolving molecular aberrations landscape.

Myelodysplastic syndromes (MDS) are clonal hematopoietic disorders with heterogeneous presentation, ranging from indolent disease courses to aggressive diseases similar to acute myeloid leukemia (AML). Approximately 90% of MDS patients harbor recurrent mutations , which - with the exception of mutated SF3B1 -have not (yet) been included into the diagnostic criteria or risk stratification for MDS. Accumulating evidence suggests their utility for diagnostic workup, treatment indication and prognosis. Subsequently, in patients with unexplained cytopenia or dysplasia identification of these mutations may lead to earlier diagnosis. The acquisition and expansion of additional driver mutations usually antecedes further disease progression to higher risk MDS or secondary AML and thus, can be clinically helpful to detect individuals that may benefit from aggressive treatment approaches. Here, we review our current understanding of somatic gene mutations, gene expression patterns and flow cytometry regarding their relevance for disease evolution from pre-neoplastic states to MDS and potentially AML.

AXL Inhibition in Macrophages Stimulates Host-versus-Leukemia Immunity and Eradicates Naïve and Treatment-Resistant Leukemia.

Acute leukemias are systemic malignancies associated with a dire outcome. Because of low immunogenicity, leukemias display a remarkable ability to evade immune control and are often resistant to checkpoint blockade. Here, we discover that leukemia cells actively establish a suppressive environment to prevent immune attacks by co-opting a signaling axis that skews macrophages toward a tumor-promoting tissue repair phenotype, namely the GAS6/AXL axis. Using aggressive leukemia models, we demonstrate that ablation of the AXL receptor specifically in macrophages, or its ligand GAS6 in the environment, stimulates antileukemic immunity and elicits effective and lasting natural killer cell- and T cell-dependent immune response against naïve and treatment-resistant leukemia. Remarkably, AXL deficiency in macrophages also enables PD-1 checkpoint blockade in PD-1-refractory leukemias. Finally, we provide proof-of-concept that a clinical-grade AXL inhibitor can be used in combination with standard-of-care therapy to cure established leukemia, regardless of AXL expression in malignant cells. SIGNIFICANCE: Alternatively primed myeloid cells predict negative outcome in leukemia. By demonstrating that leukemia cells actively evade immune control by engaging AXL receptor tyrosine kinase in macrophages and promoting their alternative priming, we identified a target which blockade, using a clinical-grade inhibitor, is vital to unleashing the therapeutic potential of myeloid-centered immunotherapy.This article is highlighted in the In This Issue feature, p. 2659.

Targeting health-related quality of life in patients with myelodysplastic syndromes - Current knowledge and lessons to be learned.

Using a range of health-related quality of life (HRQoL) instruments, most - but not all - studies of myelodysplastic syndromes (MDS) have reported that lower hemoglobin levels and red blood cell transfusion dependency are associated with worse HRQoL. In addition, some MDS treatments may significantly improve HRQoL, particularly among those patients who respond to therapy; however, the majority of these studies were underpowered for this secondary endpoint. Furthermore, decreased HRQoL has been associated with worse survival outcomes, and HRQoL scores can be used to refine classical prognostic systems. Despite the subjective nature of HRQoL, the importance and validity of measuring it in trials and clinical practice are increasingly being recognized, but properly validated MDS-specific instruments are required. We describe what is currently known about HRQoL in patients with MDS, and the limitations of measuring HRQoL, and we provide some recommendations to improve the measurement of this outcome in future trials.

Current challenges and unmet medical needs in myelodysplastic syndromes.

Myelodysplastic syndromes (MDS) represent a heterogeneous group of myeloid neoplasms that are characterized by ineffective hematopoiesis, variable cytopenias, and a risk of progression to acute myeloid leukemia. Most patients with MDS are affected by anemia and anemia-related symptoms, which negatively impact their quality of life. While many patients with MDS have lower-risk disease and are managed by existing treatments, there currently is no clear standard of care for many patients. For patients with higher-risk disease, the treatment priority is changing the natural history of the disease by delaying disease progression to acute myeloid leukemia and improving overall survival. However, existing treatments for MDS are generally not curative and many patients experience relapse or resistance to first-line treatment. Thus, there remains an unmet need for new, more effective but tolerable strategies to manage MDS. Recent advances in molecular diagnostics have improved our understanding of the pathogenesis of MDS, and it is becoming clear that the diverse nature of genetic abnormalities that drive MDS demands a complex and personalized treatment approach. This review will discuss some of the challenges related to the current MDS treatment landscape, as well as new approaches currently in development.

Iron Toxicity and Chelation Therapy in Hematopoietic Stem Cell Transplant.

Many patients with hematologic malignancies receive RBC transfusion support, which often causes systemic and tissue iron toxicity. Because of their compromised bone marrow function, hematopoietic stem cell transplant (HSCT) recipients are especially vulnerable to excess iron levels. Iron toxicity may compromise transplant engraftment and eventually promote relapse by mediating oxidative and genotoxic stress in hematopoietic stem cells (HSCs) and further impairing the already dysfunctional bone marrow microenvironment in HSCT recipients. Iron toxicity is thought to be primarily mediated by its ability to induce reactive oxygen species and trigger inflammation. Elevated iron levels in the bone marrow can decrease the number of HSCs and progenitor cells, as well as their clonogenic potential, alter mesenchymal stem cell differentiation, and inhibit the expression of chemokines and adhesion molecules involved in hematopoiesis. In vivo, in vitro, and clinical studies support the concept that iron chelation therapy may limit iron toxicity in the bone marrow and promote hematologic improvement and engraftment in HSCT recipients. This review will provide an overview of the current knowledge of the detrimental impact of iron toxicity in the setting of HSCT in patients with hematologic malignancies and the use of iron restriction approaches to improve transplant outcome.

Development of luspatercept to treat ineffective erythropoiesis.

Luspatercept (Reblozyl) was recently approved for treating patients with transfusion-dependent lower-risk myelodysplastic syndrome (MDS) with ring sideroblasts (RS) and/or SF3B1 mutation who were not eligible for erythropoiesis-stimulating agents (ESAs) or patients for whom those agents failed. Luspatercept acts as an activin receptor type IIB fusion protein ligand trap that targets the altered transforming growth factor beta pathway in MDS, which is associated with impaired terminal erythroid maturation. Treatment with luspatercept results in decreased SMAD signaling, which enables erythroid maturation by means of late-stage erythroblast differentiation and thus improves anemia. ESAs, the current standard first-line therapeutic option for anemic lower-risk patients with MDS, also improve red cell parameters mainly by expanding proliferation of early erythroid progenitor cells. However, erythropoietin (EPO) and its receptor (EPO-R) are also required for survival of late-stage definitive erythroid cells, and they play an essential role in promoting proliferation, survival, and appropriate timing of terminal maturation of primitive erythroid precursors. Thus, luspatercept joins the mechanism of ESAs in promoting erythroid maturation. Especially in the subgroup of MDS patients with RS, luspatercept showed high clinical activity for the treatment of anemia in the phase 2 (PACE-MDS) trial and subsequently in the phase 3 (MEDALIST) trial, which resulted in approval by both the US Food and Drug Administration and the European Medicines Agency in April 2020. Additional studies are needed to better understand the mechanism of action and pharmacodynamics of this novel agent in MDS.

Patient stratification in myelodysplastic syndromes: how a puzzle may become a map.

Heterogeneity is the disease-defining epithet of myelodysplastic syndromes (MDS), a clonal disorder of hematopoietic stem and progenitor cells. During the last decade, significant progress has been made to better understand the diversity of clinical, molecular, cellular, and immunological factors that are bound to the prognosis and outcomes of patients with MDS. Despite the rapid generation of all of this biological information, how to implement it has fallen short. Redefining clinical tools to use this new information remains a challenge. The holistic integration of novel, high-impact individual risk parameters such as patient-reported outcomes or mutational and immunological data into conventional risk stratification systems may further refine patient subgroups, improve predictive power for survival, and provide a next-generation classification and prognosis system for patients with MDS. Dichotomic treatment strategies in patients with MDS according to their patient and disease profiles highlight the importance of precise risk stratification, which may be complemented by the definition of granular cohorts of patients with myeloid neoplasms and a druggable target (ie, IDH1/2 mutations) across conventional blast thresholds.

Case Report: Allogeneic Stem Cell Transplantation Following Induction With CPX-351 in Patients With Acute Myeloid Leukemia Is Feasible.

Acute myeloid leukemia with myelodysplasia-related changes (AML-MRC) and treatment-related acute myeloid leukemia (tAML) after chemotherapy or radiation therapy for other neoplasms are associated with poor outcomes. CPX-351, a dual-drug liposomal encapsulation of daunorubicin and cytarabine, has been shown to improve outcomes in AML-MRC and tAML compared with standard 7+3 regimens. Here we report the cases of four consecutive patients with AML-MRC or tAML who received CPX-351 as outpatient induction therapy immediately followed by allogeneic hematopoietic stem cell transplantation (allo-HSCT). Two patients received allo-HSCT in remission (one in complete remission and one in partial remission) and two patients received allo-HSCT in aplasia (one at 11 days and one at 52 days after the start of induction therapy with CPX-351). With a median follow-up of 188 days after allo-HSCT, all but one patient are alive and two are in remission. Further studies will help define and expand the role of CPX-351 in the treatment of AML-MRC and tAML, especially in patients expected to undergo allo-HSCT.

Iron overload and its impact on outcome of patients with hematological diseases.

Systemic iron overload (SIO) is a common challenge in patients with hematological diseases and develops as a result of ineffective erythropoiesis, multiple red blood cell (RBC) transfusions and disease-specific therapies. Iron homeostasis is tightly regulated as there is no physiological pathway to excrete iron from the body. Excess iron is, therefore, stored in tissues like liver, heart and bone marrow and can lead to progressive organ damage. The presence of free iron in the form of non-transferrin bound iron (NTBI) is especially detrimental. Reactive oxygen species can also cause stromal damage in the bone marrow and promote leukemic cell growth in vitro. In acute leukemias and myelodysplastic syndromes outcome is worse in patients with SIO compared to patients without. Especially in patients undergoing allogeneic HSCT presence of NTBI before or during transplant has been shown to negatively affect non-relapse mortality and overall survival. Although the mechanisms, of how these effects are mediated by SIO are not very well understood monitoring of iron status by serum markers and imaging techniques is, therefore, mandatory especially in these patients. Whether peri-interventional iron chelation may improve outcome of these patients is part of current clinical research.

Disease management of patients with immune thrombocytopenia-results of a representative retrospective survey in Germany.

Clinical research has resulted in an improvement of treatment options for patients with immune thrombocytopenia (ITP) over the last years. However, only few data exist on the real-life management of patients with ITP. To expand the knowledge, a multicenter, national survey was undertaken in 26 hematology practices distributed all over Germany. All patients with a diagnosis of ITP were documented using questionnaires, irrespective of the diagnosis date over a period of 2 years. Overall, data of 1023 patients were evaluated with 56% of patients being older than 60 years. Seventy-nine percent of the patients had chronic (> 12 months), 16% persistent (> 3-12 months), and 5% newly diagnosed (0-3 months) ITP. In 61% of cases, the disease lasted 3 or more years before survey documentation started. Main strategies applied as first-line therapy consisted of steroids in 45% and a "watch and wait" approach in 41% of patients. During second- and third-line strategies, treatment with steroids decreased (36% and 28%, respectively), while treatment modalities such as TPO-RAs increased (19% and 26%, respectively). As expected, patients with a low platelet count and thus a higher risk for bleeding and mortality received treatment (esp. steroids) more frequently during first line than those with a higher platelet count. Up to a third of patients were treated with steroids for more than a year. Overall, our study provides a cross-section overview about the current therapeutic treatment landscape in German ITP patients. The results will help to improve therapeutic management of ITP patients.