Molecular subgroups of T-cell acute lymphoblastic leukemia in adults treated according to pediatric-based GMALL protocols

In contrast to B-cell precursor acute lymphoblastic leukemia (ALL), molecular subgroups are less well defined in T-lineage ALL. Comprehensive studies on molecular T-ALL subgroups have been predominantly performed in pediatric ALL patients. Currently, molecular characteristics are rarely considered for risk stratification. Herein, we present a homogenously treated cohort of 230 adult T-ALL patients characterized on transcriptome, and partly on DNA methylation and gene mutation level in correlation with clinical outcome. We identified nine molecular subgroups based on aberrant oncogene expression correlating to four distinct DNA methylation patterns. The subgroup distribution differed from reported pediatric T-ALL cohorts with higher frequencies of prognostic unfavorable subgroups like HOXA or LYL1/LMO2. A small subset (3%) of HOXA adult T-ALL patients revealed restricted expression of posterior HOX genes with aberrant activation of lncRNA HOTTIP. With respect to outcome, TLX1 (n = 44) and NKX2-1 (n = 4) had an exceptionally favorable 3-year overall survival (3y-OS) of 94%. Within thymic T-ALL, the non TLX1 patients had an inferior but still good prognosis. To our knowledge this is the largest cohort of adult T-ALL patients characterized by transcriptome sequencing with meaningful clinical follow-up. Risk classification based on molecular subgroups might emerge and contribute to improvements in outcome.

The immunoglobulin superfamily ligand B7H6 subjects T cell responses to NK cell surveillance

Understanding the mechanisms that regulate T cell immunity is critical for the development of effective therapies for diseases associated with T cell dysfunction, including autoimmune diseases, chronic infections, and cancer. Co-inhibitory "checkpoint molecules," such as programmed cell death protein-1, balance excessive or prolonged immune activation by T cell-intrinsic signaling. Here, by screening for mediators of natural killer (NK) cell recognition on T cells, we identified the immunoglobulin superfamily ligand B7H6 to be highly expressed by activated T cells, including patient-infused CD19-targeting chimeric antigen receptor (CAR) T cells. Unlike other checkpoint molecules, B7H6 mediated NKp30-dependent recognition and subsequent cytolysis of activated T cells by NK cells. B7H6+ T cells were prevalent in the tissue and blood of several diseases, and their abundance in tumor tissue positively correlated with clinical response in a cohort of patients with immune checkpoint inhibitor-treated esophageal cancer. In humanized mouse models, NK cell surveillance via B7H6 limited the persistence and antitumor activity of CAR T cells, and its genetic deletion enhanced T cell proliferation and persistence. Together, we provide evidence of B7H6 protein expression by activated T cells and suggest the B7H6-NKp30 axis as a therapeutically actionable NK cell-dependent immune checkpoint that regulates human T cell function.

Gemtuzumab ozogamicin plus midostaurin in combination with standard '7 + 3' induction therapy in newly diagnosed AML: Results from the SAL-MODULE phase I study

We conducted a phase I trial in newly diagnosed acute myeloid leukaemia (AML) to investigate the combination of two novel targeted agents, gemtuzumab ozogamicin (GO) and midostaurin, with intensive chemotherapy in FLT3-mutated AML and CBF leukaemia. Three dose levels of midostaurin and one to three sequential doses of 3 mg/m2 GO in combination with '7 + 3' induction were evaluated. Based on safety findings in 12 patients, our results show that 3 mg/m2 GO on Days 1 + 4 and 100 mg midostaurin on Days 8-21 can be safely combined with IC in newly diagnosed AML.

Reversible Host-Guest Crosslinks in Supramolecular Hydrogels for On-Demand Mechanical Stimulation of Human Mesenchymal Stem Cells

Stem cells are regulated not only by biochemical signals but also by biophysical properties of extracellular matrix (ECM). The ECM is constantly monitored and remodeled because the fate of stem cells can be misdirected when the mechanical interaction between cells and ECM is imbalanced. A well-defined ECM model for bone marrow-derived human mesenchymal stem cells (hMSCs) based on supramolecular hydrogels containing reversible host-guest crosslinks is fabricated. The stiffness (Young's modulus E) of the hydrogels can be switched reversibly by altering the concentration of non-cytotoxic, free guest molecules dissolved in the culture medium. Fine-adjustment of substrate stiffness enables the authors to determine the critical stiffness level E* at which hMSCs turn the mechano-sensory machinery on or off. Next, the substrate stiffness across E* is switched and the dynamic adaptation characteristics such as morphology, traction force, and YAP/TAZ signaling of hMSCs are monitored. These data demonstrate the instantaneous switching of traction force, which is followed by YAP/TAZ signaling and morphological adaptation. Periodical switching of the substrate stiffness across E* proves that frequent applications of mechanical stimuli drastically suppress hMSC proliferation. Mechanical stimulation across E* level using dynamic hydrogels is a promising strategy for the on-demand control of hMSC transcription and proliferation.

Altered serum metabolome as an indicator of paraneoplasia or concomitant cancer in patients with rheumatic disease

OBJECTIVES

A timely diagnosis is imperative for curing cancer. However, in patients with rheumatic musculoskeletal diseases (RMDs) or paraneoplastic syndromes, misleading symptoms frequently delay cancer diagnosis. As metabolic remodelling characterises both cancer and RMD, we analysed if a metabolic signature can indicate paraneoplasia (PN) or reveal concomitant cancer in patients with RMD.

METHODS

Metabolic alterations in the sera of rheumatoid arthritis (RA) patients with (n=56) or without (n=52) a history of invasive cancer were quantified by nuclear magnetic resonance analysis. Metabolites indicative of cancer were determined by multivariable regression analyses. Two independent RA and spondyloarthritis (SpA) cohorts with or without a history of invasive cancer were used for blinded validation. Samples from patients with active cancer or cancer treatment, pulmonary and lymphoid type cancers, paraneoplastic syndromes, non-invasive (NI) precancerous lesions and non-melanoma skin cancer and systemic lupus erythematosus and samples prior to the development of malignancy were used to test the model performance.

RESULTS

Based on the concentrations of acetate, creatine, glycine, formate and the lipid ratio L1/L6, a diagnostic model yielded a high sensitivity and specificity for cancer diagnosis with AUC=0.995 in the model cohort, AUC=0.940 in the blinded RA validation cohort and AUC=0.928 in the mixed RA/SpA cohort. It was equally capable of identifying cancer in patients with PN. The model was insensitive to common demographic or clinical confounders or the presence of NI malignancy like non-melanoma skin cancer.

CONCLUSIONS

This new set of metabolic markers reliably predicts the presence of cancer in arthritis or PN patients with high sensitivity and specificity and has the potential to facilitate a rapid and correct diagnosis of malignancy.

The remission status of AML patients after allo-HCT is associated with a distinct single-cell bone marrow T-cell signature

ABSTRACT

Acute myeloid leukemia (AML) is a hematologic malignancy for which allogeneic hematopoietic cell transplantation (allo-HCT) often remains the only curative therapeutic approach. However, incapability of T cells to recognize and eliminate residual leukemia stem cells might lead to an insufficient graft-versus-leukemia (GVL) effect and relapse. Here, we performed single-cell RNA-sequencing (scRNA-seq) on bone marrow (BM) T lymphocytes and CD34+ cells of 6 patients with AML 100 days after allo-HCT to identify T-cell signatures associated with either imminent relapse (REL) or durable complete remission (CR). We observed a higher frequency of cytotoxic CD8+ effector and gamma delta (γδ) T cells in CR vs REL samples. Pseudotime and gene regulatory network analyses revealed that CR CD8+ T cells were more advanced in maturation and had a stronger cytotoxicity signature, whereas REL samples were characterized by inflammatory tumor necrosis factor/NF-κB signaling and an immunosuppressive milieu. We identified ADGRG1/GPR56 as a surface marker enriched in CR CD8+ T cells and confirmed in a CD33-directed chimeric antigen receptor T cell/AML coculture model that GPR56 becomes upregulated on T cells upon antigen encounter and elimination of AML cells. We show that GPR56 continuously increases at the protein level on CD8+ T cells after allo-HCT and confirm faster interferon gamma (IFN-γ) secretion upon re-exposure to matched, but not unmatched, recipient AML cells in the GPR56+ vs GPR56- CD8+ T-cell fraction. Together, our data provide a single-cell reference map of BM-derived T cells after allo-HCT and propose GPR56 expression dynamics as a surrogate for antigen encounter after allo-HCT.

Mimicking clinical trials with synthetic acute myeloid leukemia patients using generative artificial intelligence

Clinical research relies on high-quality patient data, however, obtaining big data sets is costly and access to existing data is often hindered by privacy and regulatory concerns. Synthetic data generation holds the promise of effectively bypassing these boundaries allowing for simplified data accessibility and the prospect of synthetic control cohorts. We employed two different methodologies of generative artificial intelligence - CTAB-GAN+ and normalizing flows (NFlow) - to synthesize patient data derived from 1606 patients with acute myeloid leukemia, a heterogeneous hematological malignancy, that were treated within four multicenter clinical trials. Both generative models accurately captured distributions of demographic, laboratory, molecular and cytogenetic variables, as well as patient outcomes yielding high performance scores regarding fidelity and usability of both synthetic cohorts (n = 1606 each). Survival analysis demonstrated close resemblance of survival curves between original and synthetic cohorts. Inter-variable relationships were preserved in univariable outcome analysis enabling explorative analysis in our synthetic data. Additionally, training sample privacy is safeguarded mitigating possible patient re-identification, which we quantified using Hamming distances. We provide not only a proof-of-concept for synthetic data generation in multimodal clinical data for rare diseases, but also full public access to synthetic data sets to foster further research.

Epigenetic control over cell-intrinsic immune response antagonizes self-renewal in acute myeloid leukemia

Epigenetic modulation of the cell-intrinsic immune response holds promise as a therapeutic approach for leukemia. However, current strategies designed for transcriptional activation of endogenous transposons and subsequent interferon type-I (IFN-I) response, show limited clinical efficacy. Histone lysine methylation is an epigenetic signature in IFN-I response associated with suppression of IFN-I and IFN stimulated genes, suggesting histone demethylation as key mechanism of reactivation. In this study, we unveil the histone demethylase PHF8 as a direct initiator and regulator of cell-intrinsic immune response in acute myeloid leukemia (AML). Site-specific phosphorylation of PHF8 orchestrates epigenetic changes that upregulate cytosolic RNA sensors, particularly the TRIM25-RIG-I-IFIT5 axis, thereby triggering the cellular IFN-I response-differentiation-apoptosis network. This signaling cascade largely counteracts differentiation block and growth of human AML cells across various disease subtypes in vitro and in vivo. Through proteome analysis of over 200 primary AML bone marrow samples, we identify a distinct PHF8/IFN-I signature in half of the patient population, without significant associations with known clinically or genetically defined AML subgroups. This profile was absent in healthy CD34-positive hematopoietic progenitor cells, suggesting therapeutic applicability in a large fraction of AML patients. Pharmacological support of PHF8 phosphorylation significantly impairs growth of primary AML patient samples. These findings provide novel opportunities for harnessing the cell-intrinsic immune response in the development of immunotherapeutic strategies against AML.

Multimodal and spatially resolved profiling identifies distinct patterns of T cell infiltration in nodal B cell lymphoma entities

The redirection of T cells has emerged as an attractive therapeutic principle in B cell non-Hodgkin lymphoma (B-NHL). However, a detailed characterization of lymphoma-infiltrating T cells across B-NHL entities is missing. Here we present an in-depth T cell reference map of nodal B-NHL, based on cellular indexing of transcriptomes and epitopes, T cell receptor sequencing, flow cytometry and multiplexed immunofluorescence applied to 101 lymph nodes from patients with diffuse large B cell, mantle cell, follicular or marginal zone lymphoma, and from healthy controls. This multimodal resource revealed quantitative and spatial aberrations of the T cell microenvironment across and within B-NHL entities. Quantitative differences in PD1+ TCF7- cytotoxic T cells, T follicular helper cells or IKZF3+ regulatory T cells were linked to their clonal expansion. The abundance of PD1+ TCF7- cytotoxic T cells was associated with poor survival. Our study portrays lymphoma-infiltrating T cells with unprecedented comprehensiveness and provides a unique resource for the investigation of lymphoma biology and prognosis.

Predictors of early morbidity and mortality in newly diagnosed multiple myeloma: data from five randomized, controlled, phase III trials in 3700 patients

Early morbidity and mortality affect patient outcomes in multiple myeloma. Thus, we dissected the incidence and causes of morbidity/mortality during induction therapy (IT) for newly diagnosed multiple myeloma (NDMM), and developed/validated a predictive risk score. We evaluated 3700 transplant-eligible NDMM patients treated in 2005-2020 with novel agent-based triplet/quadruplet IT. Primary endpoints were severe infections, death, or a combination of both. Patients were divided in a training (n = 1333) and three validation cohorts (n = 2367). During IT, 11.8%, 1.8%, and 12.5% of patients in the training cohort experienced severe infections, death, or both, respectively. Four major, baseline risk factors for severe infection/death were identified: low platelet count (<150/nL), ISS III, higher WHO performance status (>1), and age (>60 years). A risk score (1 risk factor=1 point) stratified patients in low (39.5%; 0 points), intermediate (41.9%; 1 point), and high (18.6%; ≥2 points) risk. The risk for severe infection/death increased from 7.7% vs. 11.5% vs. 23.3% in the low- vs. intermediate- vs. high-risk groups (p < 0.001). The risk score was independently validated in three trials incorporating quadruplet IT with an anti-CD38 antibody. Our analyses established a robust and easy-to-use score to identify NDMM patients at risk of severe infection/death, covering the latest quadruplet induction therapies. Trial registrations: HOVON-65/GMMG-HD4: EudraCT No. 2004-000944-26. GMMG-MM5: EudraCT No. 2010-019173-16. GMMG-HD6: NCT02495922. EMN02/HOVON-95: NCT01208766. GMMG-HD7: NCT03617731.

Randomized phase III GnG study on two schedules of gemtuzumab ozogamicin as adjunct to intensive induction therapy and double-blinded intensive post-remission therapy with or without glasdegib in patients with newly diagnosed acute myeloid leukemia

Not available.

Extracorporeal photopheresis as a promising strategy for the treatment of GvHD after CAR-T cell therapy

Graft-versus-host disease (GvHD) occurs in about 10-33% of patients receiving "al-logeneic" or "autologous" CAR-T cells after preceding allogeneic hematopoietic stem cell transplantation (allo-HSCT) due to the substantial presence of alloreactive T cells. Extracorporeal photopheresis (ECP) shows promising clinical outcomes in the treatment of GvHD after allo-HSCT without hampering anti-tumor and anti-viral effects. This raises an interesting question: whether ECP might constitute a new way to treat patients with GvHD after CAR-T cell therapy without compromising CAR-T cells significantly. Third-generation CD19-specific CAR-T cells were generated and an in vitro ECP protocol was established. The impact of ECP on CAR-T cells was comprehensively investigated in two models: the non-dilution model reflects days following CAR-T cell infusion and the dilution model weeks after infusion. The ther-apeutic effect of ECP on GvHD was examined in an in vitro mixed lymphocyte reac-tion (MLR) assay. We found out that ECP treated CAR-T cells demonstrated reduced potency in inducing alloreaction compared to the group without ECP treatment in MLR assay. ECP could selectively induce apoptosis, thereby enriching the naive and central memory CAR-T cells with a reduced alloreactivity. The cytokine milieu of CAR-T cells could be switched from immune stimulation to immune tolerance in both models. Moreover, ECP could modulate the proliferative capacity of CAR-T cells without hampering their long-term functionality in the dilution model. In con-clusion, ECP constitutes a promising treatment strategy for GvHD after allo-HSCT and CAR-T cell transfusion, as ECP reduces the alloreactivity without hampering CAR-T cell functionality.

In Vitro Functionality and Endurance of GMP-Compliant Point-of-Care BCMA.CAR-T Cells at Different Timepoints of Cryopreservation

The search for target antigens for CAR-T cell therapy against multiple myeloma defined the B-cell maturation antigen (BCMA) as an interesting candidate. Several studies with BCMA-directed CAR-T cell therapy showed promising results. Second-generation point-of-care BCMA.CAR-T cells were manufactured to be of a GMP (good manufacturing practice) standard using the CliniMACS Prodigy® device. Cytokine release in BCMA.CAR-T cells after stimulation with BCMA positive versus negative myeloma cell lines, U266/HL60, was assessed via intracellular staining and flow cytometry. The short-term cytotoxic potency of CAR-T cells was evaluated by chromium-51 release, while the long-term potency used co-culture (3 days/round) at effector/target cell ratios of 1:1 and 1:4. To evaluate the activation and exhaustion of CAR-T cells, exhaustion markers were assessed via flow cytometry. Stability was tested through a comparison of these evaluations at different timepoints: d0 as well as d + 14, d + 90 and d + 365 of cryopreservation. As results, (1) Killing efficiency of U266 cells correlated with the dose of CAR-T cells in a classical 4 h chromium-release assay. There was no significant difference after cryopreservation on different timepoints. (2) In terms of endurance of BCMA.CAR-T cell function, BCMA.CAR-T cells kept their ability to kill all tumor cells over six rounds of co-culture. (3) BCMA.CAR-T cells released high amounts of cytokines upon stimulation with tumor cells. There was no significant difference in cytokine release after cryopreservation. According to the results, BCMA.CAR-T cells manufactured under GMP conditions exerted robust and specific killing of target tumor cells with a high release of cytokines. Even after 1 year of cryopreservation, cytotoxic functions were maintained at the same level. This gives clinicians sufficient time to adjust the timepoint of BCMA.CAR-T cell application to the patient's course of the underlying disease.

DNMT3A clonal hematopoiesis-driver mutations induce cardiac fibrosis by paracrine activation of fibroblasts

Hematopoietic mutations in epigenetic regulators like DNA methyltransferase 3 alpha (DNMT3A), play a pivotal role in driving clonal hematopoiesis of indeterminate potential (CHIP), and are associated with unfavorable outcomes in patients suffering from heart failure (HF). However, the precise interactions between CHIP-mutated cells and other cardiac cell types remain unknown. Here, we identify fibroblasts as potential partners in interactions with CHIP-mutated monocytes. We used combined transcriptomic data derived from peripheral blood mononuclear cells of HF patients, both with and without CHIP, and cardiac tissue. We demonstrate that inactivation of DNMT3A in macrophages intensifies interactions with cardiac fibroblasts and increases cardiac fibrosis. DNMT3A inactivation amplifies the release of heparin-binding epidermal growth factor-like growth factor, thereby facilitating activation of cardiac fibroblasts. These findings identify a potential pathway of DNMT3A CHIP-driver mutations to the initiation and progression of HF and may also provide a compelling basis for the development of innovative anti-fibrotic strategies.

The relevance of the hematopoietic niche for therapy resistance in acute myeloid leukemia

The expansion of acute myeloid leukemia (AML) blasts not only suppresses normal hematopoiesis, but also alters the microenvironment. The interplay of different components of the bone marrow gives rise to altered metabolic states and activates signaling pathways which lead to resistance and impede effective therapy. Therefore, the underlying processes and mechanisms represent attractive therapeutic leverage points for overcoming therapy resistance in AML. Here, we briefly discuss resistance mechanisms based on cell interactions and secreted soluble factors in the hematopoietic niche and provide an overview of niche-related therapeutic targets currently undergoing preclinical and clinical investigation which may help improve the outcome in AML therapy.

Sequence diversity of kappa light chains from patients with AL amyloidosis and multiple myeloma

BACKGROUND

AL amyloidosis (AL) results from the misfolding of immunoglobulin light chains (IG LCs). Aim of this study was to comprehensively analyse kappa LC sequences from AL patients in comparison with multiple myeloma (MM).

OBJECTIVE

We analysed IGKV/IGKJ usage and associated organ tropism and IGKV1/D-33 in terms of mutational analysis and theoretical biochemical properties.

MATERIAL AND METHODS

cDNA and bulk RNA sequencing of the LCs of AL and MM patients.

RESULTS

We studied 41 AL and 83 MM patients showing that IGKV1 was most expressed among kappa AL and MM, with higher frequency in AL (80% vs. 53%, p = .002). IGKV3 was underrepresented in AL (10% vs. 30%, p = .014). IGKJ2 was more commonly used in AL than in MM (39% vs. 29%). Patients with IGKV1/D-33 were associated with heart involvement (75%, p = .024). IGKV1/D-33-segments of AL had a higher mutation count (AL = 12.0 vs. MM = 10.0). FR3 and CDR3 were most frequently mutated in both, with a median mutation count in FR3 being the highest (AL = 4.0; MM = 3.5) and one mutation hotspot (FR3 (83I)) for IGKV1/D-33/IGKJ2 was associated with cardiac involvement.

CONCLUSION

This study confirmed that germline usage has an influence on AL amyloidosis risk and organ involvement.

Symptomatic Patients with Hyperleukocytic FLT3-ITD Mutated Acute Myeloid Leukemia Might Benefit from Leukapheresis

PURPOSE

We aimed to identify subsets of patients who benefit from emergency LA and to establish a therapeutic algorithm for AML patients with hyperleukocytosis.

METHODS

In this single-center retrospective cohort study, a total of 20 consecutive patients underwent LA because of their clinical symptoms. Overall survival (OS) analysis was conducted using the Kaplan-Meier plot method. Univariate and multivariate analyses (using multiple logistic regression) were performed. At the time of diagnosis, all patients received a standard diagnostic workup for AML including FLT3-ITD mutational analysis.

RESULTS

FLT3-ITD mut AML patients receiving LA had a median OS of 437 days (range 5-2379 days) with a corresponding 14-day survival of 92.3%, while FLT3 wt AML patients displayed a significantly lower median OS of only 5 days (range 1-203 days) with a corresponding 14-day survival of 14.3% (p = 0.0001).

CONCLUSIONS

Among patients with clinical symptoms of leukostasis, the subset of FLT3-ITD mut AML patients showed a better outcome with lower early mortality after emergency LA. Based on these observations, we established a therapeutic algorithm for AML patients with hyperleukocytosis.

Human and mouse neutrophils share core transcriptional programs in both homeostatic and inflamed contexts

Neutrophils are frequently studied in mouse models, but the extent to which findings translate to humans remains poorly defined. In an integrative analysis of 11 mouse and 13 human datasets, we find a strong correlation of neutrophil gene expression across species. In inflammation, neutrophils display substantial transcriptional diversity but share a core inflammation program. This program includes genes encoding IL-1 family members, CD14, IL-4R, CD69, and PD-L1. Chromatin accessibility of core inflammation genes increases in blood compared to bone marrow and further in tissue. Transcription factor enrichment analysis implicates members of the NF-κB family and AP-1 complex as important drivers, and HoxB8 neutrophils with JunB knockout show a reduced expression of core inflammation genes in resting and activated cells. In independent single-cell validation data, neutrophil activation by type I or type II interferon, G-CSF, and E. coli leads to upregulation in core inflammation genes. In COVID-19 patients, higher expression of core inflammation genes in neutrophils is associated with more severe disease. In vitro treatment with GM-CSF, LPS, and type II interferon induces surface protein upregulation of core inflammation members. Together, we demonstrate transcriptional conservation in neutrophils in homeostasis and identify a core inflammation program shared across heterogeneous inflammatory conditions.

High-throughput electron tomography identifies centriole over-elongation as an early event in plasma cell disorders

Plasma cell disorders are clonal outgrowths of pre-malignant or malignant plasma cells, characterized by extensive chromosomal aberrations. Centrosome abnormalities are a major driver of chromosomal instability in cancer but their origin, incidence, and composition in primary tumor cells is poorly understood. Using cutting-edge, semi-automated high-throughput electron tomography, we characterized at nanoscale 1386 centrioles in CD138pos plasma cells from eight healthy donors and 21 patients with plasma cell disorders, and 722 centrioles from different control populations. In plasma cells from healthy individuals, over-elongated centrioles accumulated with age. In plasma cell disorders, centriole over-elongation was notably frequent in early, pre-malignant disease stages, became less pronounced in overt multiple myeloma, and almost entirely disappeared in aggressive plasma cell leukemia. Centrioles in other types of patient-derived B cell neoplasms showed no over-elongation. In contrast to current belief, centriole length appears to be highly variable in long-lived, healthy plasma cells, and over-elongation and structural aberrations are common in this cell type. Our data suggest that structural centrosome aberrations accumulate with age in healthy CD138pos plasma cells and may thus play an important role in early aneuploidization as an oncogenic driver in plasma cell disorders.

A precision-based exercise program for patients with multiple myeloma

OBJECTIVES

Aim of this study was to retrospectively evaluate an interdisciplinary consultation followed by a precision-based exercise program (PEP) for myeloma patients with stable and unstable bone lesions.

METHODS

Data of myeloma patients (n = 100) who received a PEP according to an orthopedic evaluation were analyzed. Bone stability was assessed by established scoring systems (Spinal Instability Neoplastic Score [SINS], Mirels' score). All patients with stable and unstable osteolyses received a PEP and n = 91 were contacted for a follow-up interview.

RESULTS

In 60% of patients at least one osteolysis of the spine was considered potentially unstable or unstable. Following consultation, the number of patients performing resistance training could be significantly increased (≥2 sessions/week, 55%). Musculoskeletal pain was reported frequently. At the follow-up interview, 75% of patients who performed PEP stated that painful symptoms could be effectively alleviated by exercise. Moreover, only patients who exercised regularly discontinued pain medication. No injuries were reported in association with PEP.

CONCLUSION

We were able to demonstrate that individualized resistance training is implementable and safe for myeloma patients. By means of a PEP, patients' self-efficacy in managing musculoskeletal pain was enhanced and pain medication could be reduced.

Mutated IKZF1 is an independent marker of adverse risk in acute myeloid leukemia

Genetic lesions of IKZF1 are frequent events and well-established markers of adverse risk in acute lymphoblastic leukemia. However, their function in the pathophysiology and impact on patient outcome in acute myeloid leukemia (AML) remains elusive. In a multicenter cohort of 1606 newly diagnosed and intensively treated adult AML patients, we found IKZF1 alterations in 45 cases with a mutational hotspot at N159S. AML with mutated IKZF1 was associated with alterations in RUNX1, GATA2, KRAS, KIT, SF3B1, and ETV6, while alterations of NPM1, TET2, FLT3-ITD, and normal karyotypes were less frequent. The clinical phenotype of IKZF1-mutated AML was dominated by anemia and thrombocytopenia. In both univariable and multivariable analyses adjusting for age, de novo and secondary AML, and ELN2022 risk categories, we found mutated IKZF1 to be an independent marker of adverse risk regarding complete remission rate, event-free, relapse-free, and overall survival. The deleterious effects of mutated IKZF1 also prevailed in patients who underwent allogeneic hematopoietic stem cell transplantation (n = 519) in both univariable and multivariable models. These dismal outcomes are only partially explained by the hotspot mutation N159S. Our findings suggest a role for IKZF1 mutation status in AML risk modeling.

Clonal hematopoiesis with DNMT3A and PPM1D mutations impairs regeneration in autologous stem cell transplant recipients

Clonal hematopoiesis (CH) is an age-related condition driven by stem and progenitor cells harboring recurrent mutations linked to myeloid neoplasms. Currently, potential effects on hematopoiesis, stem cell function and regenerative potential under stress conditions are unknown. We performed targeted DNA sequencing of 457 hematopoietic stem cell grafts collected for autologous stem cell transplantation (ASCT) in myeloma patients and correlated our findings with high-dimensional longitudinal clinical and laboratory data (26,510 data points for blood cell counts/serum values in 25 days around transplantation). We detected CHrelated mutations in 152 patients (33.3%). Since many patients (n=54) harbored multiple CH mutations in one or more genes, we applied a non-negative matrix factorization (NMF) clustering algorithm to identify genes that are commonly co-mutated in an unbiased approach. Patients with CH were assigned to one of three clusters (C1-C3) and compared to patients without CH (C0) in a gene specific manner. To study the dynamics of blood cell regeneration following ASCT, we developed a time-dependent linear mixed effect model to validate differences in blood cell count trajectories amongst different clusters. The results demonstrated that C2, composed of patients with DNMT3A and PPM1D single and co-mutated CH, correlated with reduced stem cell yields and delayed platelet count recovery following ASCT. Also, the benefit of maintenance therapy was particularly strong in C2 patients. Taken together, these data indicate an impaired regenerative potential of hematopoietic stem cell grafts harboring CH with DNMT3A and PPM1D mutations.

Ex vivo drug response profiling for response and outcome prediction in hematologic malignancies: the prospective non-interventional SMARTrial

Ex vivo drug response profiling is a powerful tool to study genotype-drug response associations and is being explored as a tool set for precision medicine in cancer. Here we conducted a prospective non-interventional trial to investigate feasibility of ex vivo drug response profiling for treatment guidance in hematologic malignancies (SMARTrial, NCT03488641 ). The primary endpoint to provide drug response profiling reports within 7 d was met in 91% of all study participants (N = 80). Secondary endpoint analysis revealed that ex vivo resistance to chemotherapeutic drugs predicted chemotherapy treatment failure in vivo. We confirmed the predictive value of ex vivo response to chemotherapy in a validation cohort of 95 individuals with acute myeloid leukemia treated with daunorubicin and cytarabine. Ex vivo drug response profiles improved ELN-22 risk stratification in individuals with adverse risk. We conclude that ex vivo drug response profiling is clinically feasible and has the potential to predict chemotherapy response in individuals with hematologic malignancies beyond clinically established genetic markers.

Stem cell collection after lenalidomide, bortezomib and dexamethasone plus elotuzumab or isatuximab in newly diagnosed multiple myeloma patients: a single centre experience from the GMMG-HD6 and -HD7 trials

BACKGROUND

While quadruplet induction therapies deepen responses in newly diagnosed multiple myeloma patients, their impact on peripheral blood stem cell (PBSC) collection remains incompletely understood. This analysis aims to evaluate the effects of prolonged lenalidomide induction and isatuximab- or elotuzumab-containing quadruplet induction therapies on PBSC mobilization and collection.

METHODS

A total of 179 transplant-eligible patients with newly diagnosed MM treated at a single academic center were included. The patients were evaluated based on PBSC mobilization and collection parameters, including overall collection results, CD34+ cell levels in peripheral blood, leukapheresis (LP) delays, overall number of LP sessions, and the rate of rescue mobilization with plerixafor. The patients underwent four different induction regimens: Lenalidomide, bortezomib, and dexamethasone (RVd, six 21-day cycles, n = 44), isatuximab-RVd (six 21-day cycles, n = 35), RVd (four 21-day cycles, n = 51), or elotuzumab-RVd (four 21-day cycles, n = 49).

RESULTS

The patients' characteristics were well balanced across the different groups. Collection failures, defined as the inability to collect three sufficient PBSC transplants, were rare (n = 3, 2%), with no occurrences in the isatuximab-RVd and elotuzumab-RVd groups. Intensified induction with six 21-day cycles of RVd did not negatively impact the overall number of collected PBSCs (9.7 × 106/kg bw versus 10.5 × 106/kg bw, p = 0.331) compared to four 21-day cycles of RVd. Plerixafor usage was more common after six cycles of RVd compared to four cycles (16% versus 8%). Addition of elotuzumab to RVd did not adversely affect overall PBSC collection (10.9 × 106/kg bw versus 10.5 × 106/kg bw, p = 0.915). Patients treated with isatuximab-RVd (six cycles) had lower numbers of collected stem cells compared to those receiving RVd (six cycles) induction (8.8 × 106/kg bw versus 9.7 × 106/kg bw, p = 0.801), without experiencing significant delays in LP or increased numbers of LP sessions in a multivariable logistic regression analysis. Plerixafor usage was more common after isatuximab plus RVd compared to RVd alone (34% versus 16%).

CONCLUSIONS

This study demonstrates that stem cell collection is feasible after prolonged induction with isatuximab-RVd without collection failures and might be further explored as induction therapy.

TRIAL REGISTRATION

Patients were treated within the randomized phase III clinical trials GMMG-HD6 (NCT02495922, 24/06/2015) and GMMG-HD7 (NCT03617731, 24/07/2018). However, during stem cell mobilization and -collection, no study-specific therapeutic intervention was performed.

Resolving therapy resistance mechanisms in multiple myeloma by multiomics subclone analysis

Intratumor heterogeneity as a clinical challenge becomes most evident after several treatment lines, when multidrug-resistant subclones accumulate. To address this challenge, the characterization of resistance mechanisms at the subclonal level is key to identify common vulnerabilities. In this study, we integrate whole-genome sequencing, single-cell (sc) transcriptomics (scRNA sequencing), and chromatin accessibility (scATAC sequencing) together with mitochondrial DNA mutations to define subclonal architecture and evolution for longitudinal samples from 15 patients with relapsed or refractory multiple myeloma. We assess transcriptomic and epigenomic changes to resolve the multifactorial nature of therapy resistance and relate it to the parallel occurrence of different mechanisms: (1) preexisting epigenetic profiles of subclones associated with survival advantages, (2) converging phenotypic adaptation of genetically distinct subclones, and (3) subclone-specific interactions of myeloma and bone marrow microenvironment cells. Our study showcases how an integrative multiomics analysis can be applied to track and characterize distinct multidrug-resistant subclones over time for the identification of molecular targets against them.

First third-generation CAR T cell application targeting CD19 for the treatment of systemic IgM AL amyloidosis with underlying marginal zone lymphoma

Light chain amyloidosis (AL) is a rare disease caused by the generalized deposition of misfolded free light chains. Patients with immunoglobulin M gammopathy (IgM) and indolent B-cell lymphoma such as marginal zone lymphoma (MZL) may in some instances develop AL amyloidosis. So far, CAR T cells for AL amyloidosis have only been reported utilizing the B cell maturation antigen as target, while CD19 has so far not been used in AL amyloidosis.We report the case of a 71-year-old male, diagnosed with systemic AL kappa amyloidosis and MZL, receiving third-generation CAR T cell therapy targeting CD19. Prior treatment included bendamustine/rituximab and cyclophosphamide/ dexamethasone with subsequent autologous stem cell transplantation. CAR T application was well tolerated despite heart and kidney amyloid manifestations, and only early low-grade procedure-specific toxicities were observed. A continuous decrease in IgM, kappa light chains and kappa-to-lambda light chain difference was observed in the patient from day + 30 on, resulting in a deep hematological response six months after treatment.In summary, we present a novel case of CAR T cell treatment with third generation CD19 directed infusion for AL amyloidosis with an underlying secretory active B cell lymphoma, showing that this is an effective treatment modality and can be applied to patients with subsequent AL amyloidosis.

Comparing the value of mono- vs coculture for high-throughput compound screening in hematological malignancies

Large-scale compound screens are a powerful model system for understanding variability of treatment response and discovering druggable tumor vulnerabilities of hematological malignancies. However, as mostly performed in a monoculture of tumor cells, these assays disregard modulatory effects of the in vivo microenvironment. It is an open question whether and to what extent coculture with bone marrow stromal cells could improve the biological relevance of drug testing assays over monoculture. Here, we established a high-throughput platform to measure ex vivo sensitivity of 108 primary blood cancer samples to 50 drugs in monoculture and coculture with bone marrow stromal cells. Stromal coculture conferred resistance to 52% of compounds in chronic lymphocytic leukemia (CLL) and 36% of compounds in acute myeloid leukemia (AML), including chemotherapeutics, B-cell receptor inhibitors, proteasome inhibitors, and Bromodomain and extraterminal domain inhibitors. Only the JAK inhibitors ruxolitinib and tofacitinib exhibited increased efficacy in AML and CLL stromal coculture. We further confirmed the importance of JAK-STAT signaling for stroma-mediated resistance by showing that stromal cells induce phosphorylation of STAT3 in CLL cells. We genetically characterized the 108 cancer samples and found that drug-gene associations strongly correlated between monoculture and coculture. However, effect sizes were lower in coculture, with more drug-gene associations detected in monoculture than in coculture. Our results justify a 2-step strategy for drug perturbation testing, with large-scale screening performed in monoculture, followed by focused evaluation of potential stroma-mediated resistances in coculture.

Impact of Clinical Parameters and Induction Regimens on Peripheral Blood Stem-Cell Mobilization and Collection in Multiple Myeloma Patients

Introduction

High-dose chemotherapy (HDCT) followed by autologous blood stem-cell transplantation (ABSCT) remains the standard consolidation therapy for newly diagnosed eligible multiple myeloma (MM) patients. As a prerequisite, peripheral blood stem cells (PBSCs) must be mobilized and collected by leukapheresis (LP). Many factors can hamper PBSC mobilization/collection. Here, we provide a comprehensive multiparametric assessment of PBSC mobilization/collection outcome parameters in a large cohort.

Methods

In total, 790 MM patients (471 [60%] male, 319 [40%] female) who underwent PBSC mobilization/collection during first-line treatment were included. Evaluated PBSC mobilization/collection outcome parameters included the prolongation of PBSC mobilization, plerixafor administration, number of LP sessions, and overall PBSC collection goal/result.

Results

741 (94%) patients received cyclophosphamide/adriamycin/dexamethasone (CAD) and granulocyte-colony-stimulating factor (G-CSF) mobilization. Plerixafor was administered in 80 (10%) patients. 489 (62%) patients started LP without delay. 530 (67%) patients reached the PBSC collection goal at the first LP session. The mean overall PBSC collection result was 10.3 (standard deviation [SD] 4.4) × 106 CD34+ cells/kg. In a multiparametric analysis, variables negatively associated with PBSC mobilization/collection outcomes were female gender, age >60 years, an advanced ISS stage, and local radiation pre-/during induction, but not remission status postinduction. Notably, the identified risk factors contributed differently to each PBSC mobilization/collection outcome parameter. In this context, compared to all other induction regimens, lenalidomide-based induction with/without antibodies negatively affected only the number of LP sessions required to reach the collection goal, but no other PBSC mobilization/collection outcome parameters. In contrast, the probability of reaching a high collection goal of ≥6 × 106 CD34+ cells/kg body weight was higher after lenalidomide-based induction compared to VCD/PAD or VAD - taking into account - that a higher G-SCF dosage was given in approximately one-third of patients receiving lenalidomide-based induction with/without antibodies.

Conclusion

Considering the identified risk factors in the clinical setting can contribute to optimized PBSC mobilization/collection. Moreover, our study demonstrates the necessity for a differentiated evaluation of PBSC mobilization/collection outcome parameters.

Impact of BMI on patient outcome in acute myeloid leukaemia patients receiving intensive induction therapy: a real-world registry experience

BACKGROUND

Acute myeloid leukaemia (AML) is treated with intensive induction chemotherapy (IT) in medically fit patients. In general, obesity was identified as a risk factor for all-cause mortality, and there is an ongoing debate on its impact on outcome and optimal dosing strategy in obese AML patients.

METHODS

We conducted a registry study screening 7632 patients and assessed the impact of obesity in 1677 equally IT treated, newly diagnosed AML patients on the outcome (OS, EFS, CR1), comorbidities, toxicities and used dosing strategies.

RESULTS

Obese patients (BMI ≥ 30) displayed a significant inferior median OS (29.44 vs. 47.94 months, P = 0.015) and CR1 rate (78.7% vs. 84.3%, P = 0.015) without differences in median EFS (7.8 vs. 9.89 months, P = 0.3) compared to non-obese patients (BMI < 30). The effect was predominantly observed in older (≥60 years) patients. Obesity was identified as an independent risk factor for death, and obese patients demonstrated higher rates of cardiovascular or metabolic comorbidities. No differences for OS, EFS, CR1 or treatment-related toxicities were observed by stratification according to used dosing strategy or dose reduction.

CONCLUSIONS

In conclusion, this study identifies obesity as an independent risk factor for worse OS in older AML patients undergoing curative IT most likely due to obesity-related comorbidities and not to dosing strategy.

Autologous Stem Cell Collection after Daratumumab, Bortezomib, Thalidomide, and Dexamethasone versus Bortezomib, Cyclophosphamide, and Dexamethasone in Newly Diagnosed Multiple Myeloma

Introduction

In transplant-eligible, newly diagnosed multiple myeloma (NDMM) patients, autologous peripheral blood stem cell (PBSC) collection is usually pursued after induction therapy. While induction regimens are constantly refined regarding response, their impact on PBSC collection is not fully studied. The inclusion of the anti-CD38 antibody daratumumab into induction therapy significantly improved outcomes for patients with NDMM, e.g., as part of the daratumumab, bortezomib, thalidomide, and dexamethasone (Dara-VTD) protocol. Preliminary data from the phase 3 CASSIOPEIA study proved the efficacy of Dara-VTD. While overall PBSC collection upon addition of daratumumab was reduced in the study population, more detailed analyses on the impact are missing.

Methods

We here report on PBSC mobilization and collection metrics in n = 119 patients with NDMM who underwent induction therapy with bortezomib, cyclophosphamide, and dexamethasone (VCD, n = 61) or Dara-VTD (n = 58).

Results

Patient characteristics were well balanced between groups. The Dara-VTD group showed improved response parameters with 66% of patients reaching at least very good partial response versus 54% in the VCD group. Dara-VTD patients exhibited inferior mobilization metrics such as peripheral blood CD34+ cell count at the first leukapheresis (LP) session (65 vs. 106/μL, p = 0.001), median number of LP sessions (2 vs. 1, p = 0.001), and PBSC collection at first LP (5.5 vs. 8.3 × 106/kg body weight [bw], p = 0.001). Utilization of plerixafor was slightly higher after Dara-VTD (33% vs. 21% of patients, p = 0.143). The overall PBSC collection result was significantly lower after Dara-VTD (8.4 vs. 9.6 × 106/kg bw, p = 0.026). 78% and 85% of patients successfully collected 3 transplants with ≥2 × 106 CD34+ cells/kg bw in the Dara-VTD and the VCD groups, respectively.

Conclusion

In summary, Dara-VTD, possibly due to both anti-CD38 antibody and thalidomide exposure, imposes a limitation on PBSC collection which can be only partly overcome by utilization of plerixafor.

Idecabtagene Vicleucel Is Well Tolerated and Effective in Relapsed/Refractory Myeloma Patients with Prior Allogeneic Stem Cell Transplantation

BCMA-specific chimeric-antigen receptor (CAR-) T cell therapy has led to high response rates and durable remissions in patients with relapsed refractory multiple myeloma. However, little data are available for patients after prior allogeneic stem cell transplantation (allo-SCT) in whom T cells are chimeric. In this study, we aimed to assess the safety and efficacy of patient-derived donor CAR-T therapy in myeloma patients with prior allo-SCT, particularly with regard to graft-versus-host disease (GVHD). We report a comprehensive clinical analysis of 3 patients who had previously undergone allo-SCT for high-risk myeloma and were treated with idecabtagene vicleucel (ide-cel) at our institution. Ide-cel was well tolerated, with no clinically relevant immune effector cell-associated neurotoxicity syndrome or cytokine release syndrome observed in any patient. Importantly, no new GVHD was observed, even though all patients had a history of GVHD. All patients responded to treatment with at least a very good partial remission. Two patients relapsed within 6 months, and 1 patient was still in stringent complete remission at the time of this report. Our findings demonstrate that treatment with ide-cel is feasible, very well tolerated, and effective in patients with relapsed/refractory multiple myeloma after prior allo-SCT.

Q-HAM: a multicenter upfront randomized phase II trial of quizartinib and high-dose Ara-C plus mitoxantrone in relapsed/refractory AML with FLT3-ITD

BACKGROUND

About 50% of older patients with acute myeloid leukemia (AML) fail to attain complete remission (CR) following cytarabine plus anthracycline-based induction therapy. Salvage chemotherapy regimens are based on high-dose cytarabine (HiDAC), which is frequently combined with mitoxantrone (HAM regimen). However, CR rates remain low, with less than one-third of the patients achieving a CR. FLT3-ITD has consistently been identified as an unfavorable molecular marker in both relapsed and refractory (r/r)-AML. One-quarter of patients who received midostaurin are refractory to induction therapy and relapse rate at 2 years exceeds 40%. The oral second-generation bis-aryl urea tyrosine kinase inhibitor quizartinib is a very selective FLT3 inhibitor, has a high capacity for sustained FLT3 inhibition, and has an acceptable toxicity profile.

METHODS

In this multicenter, upfront randomized phase II trial, all patients receive quizartinib combined with HAM (cytarabine 3g/m2 bidaily day one to day three, mitoxantrone 10mg/m2 days two and three) during salvage therapy. Efficacy is assessed by comparison to historical controls based on the matched threshold crossing approach with achievement of CR, complete remission with incomplete hematologic recovery (CRi), or complete remission with partial recovery of peripheral blood counts (CRh) as primary endpoint. During consolidation therapy (chemotherapy and allogeneic hematopoietic cell transplantation), patients receive either prophylactic quizartinib therapy or measurable residual disease (MRD)-triggered preemptive continuation therapy with quizartinib according to up-front randomization. The matched threshold crossing approach is a novel study-design to enhance the classic single-arm trial design by including matched historical controls from previous clinical studies. It overcomes common disadvantages of single-armed and small randomized studies, since the expected outcome of the observed study population can be adjusted based on the matched controls with a comparable distribution of known prognostic and predictive factors. Furthermore, balanced treatment groups lead to stable statistical models. However, one of the limitations of our study is the inability to adjust for unobserved or unknown confounders. Addressing the primary endpoint, CR/CRi/CRh after salvage therapy, the maximal sample size of 80 patients is assessed generating a desirable power of the used adaptive design, assuming a logistic regression is performed at a one-sided significance level α=0.05, the aspired power is 0.8, and the number of matching partners per intervention patient is at least 1. After enrolling 20 patients, the trial sample size will be recalculated in an interim analysis based on a conditional power argument.

CONCLUSION

Currently, there is no commonly accepted standard for salvage chemotherapy treatment. The objective of the salvage therapy is to reduce leukemic burden, achieve the best possible remission, and perform a hemopoietic stem-cell transplantation. Thus, in patients with FLT3-ITD mutation, the comparison of quizartinib with intensive salvage therapy versus chemotherapy alone appears as a logical consequence in terms of efficacy and safety.

ETHICS AND DISSEMINATION

Ethical approval and approvals from the local and federal competent authorities were granted. Trial results will be reported via peer-reviewed journals and presented at conferences and scientific meetings.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03989713; EudraCT Number: 2018-002675-17.

Midostaurin in addition to intensive chemotherapy in acute myeloid leukemia with t(8;21) and KIT and/or FLT3- ITD mutations: results of the SAL MIDOKIT trial

Not available.

Comparison of IGLV2-14 light chain sequences of patients with AL amyloidosis or multiple myeloma

Light chain amyloidosis (AL) is one of the most common forms of systemic amyloidosis and is caused by the deposition of insoluble fibrils derived from misfolded and aggregated immunoglobulin light chains (LC). To uncover the causes leading to this aggregation, we compared AL LC sequences with those of patients with the related disease multiple myeloma (MM), which do not aggregate in insoluble fibrils in vivo. IGLV2-14 is one of the most common AL-associated IGLV subfamilies. Here, we analysed IGLV2-14 LC sequences of 13 AL and eight MM patients in detail. We found that AL-associated LCs presented a lower median mutation count (7.0 vs. 11.5 in MM; P = 0.045), as well as an overall composition of less charged amino acids than MM LCs. However, we did not find a mutation that was present in ≥ 50% of the AL and not in the MM sequences. Furthermore, we did not find a significant difference in the isoelectric point (pI) in general, suggesting similar stability of the LCs in AL and MM. However, the subgroup of patients without a detectable heavy chain stood out. Surprisingly, they are characterized by an increase in mutation count (median 7.0 vs. 5.5) and pI (median 7.82 vs. 6.44, P = 0.043). In conclusion, our data suggest that the amount of mutations and the introduction of charges play a crucial role in AL fibril formation, as well as the absence or presence of a potential heavy chain binding partner.

Resolving the spatial architecture of myeloma and its microenvironment at the single-cell level

In multiple myeloma spatial differences in the subclonal architecture, molecular signatures and composition of the microenvironment remain poorly characterized. To address this shortcoming, we perform multi-region sequencing on paired random bone marrow and focal lesion samples from 17 newly diagnosed patients. Using single-cell RNA- and ATAC-seq we find a median of 6 tumor subclones per patient and unique subclones in focal lesions. Genetically identical subclones display different levels of spatial transcriptional plasticity, including nearly identical profiles and pronounced heterogeneity at different sites, which can include differential expression of immunotherapy targets, such as CD20 and CD38. Macrophages are significantly depleted in the microenvironment of focal lesions. We observe proportional changes in the T-cell repertoire but no site-specific expansion of T-cell clones in intramedullary lesions. In conclusion, our results demonstrate the relevance of considering spatial heterogeneity in multiple myeloma with potential implications for models of cell-cell interactions and disease progression.

The ribosomal protein S6 kinase alpha-1 (RPS6KA1) induces resistance to venetoclax/azacitidine in acute myeloid leukemia

Venetoclax/azacitidine combination therapy is effective in acute myeloid leukemia (AML) and tolerable for older, multimorbid patients. Despite promising response rates, many patients do not achieve sustained remission or are upfront refractory. Identification of resistance mechanisms and additional therapeutic targets represent unmet clinical needs. By using a genome-wide CRISPR/Cas9 library screen targeting 18,053 protein- coding genes in a human AML cell line, various genes conferring resistance to combined venetoclax/azacitidine treatment were identified. The ribosomal protein S6 kinase A1 (RPS6KA1) was among the most significantly depleted sgRNA-genes in venetoclax/azacitidine- treated AML cells. Addition of the RPS6KA1 inhibitor BI-D1870 to venetoclax/azacitidine decreased proliferation and colony forming potential compared to venetoclax/azacitidine alone. Furthermore, BI-D1870 was able to completely restore the sensitivity of OCI-AML2 cells with acquired resistance to venetoclax/azacitidine. Analysis of cell surface markers revealed that RPS6KA1 inhibition efficiently targeted monocytic blast subclones as a potential source of relapse upon venetoclax/azacitidine treatment. Taken together, our results suggest RPS6KA1 as mediator of resistance towards venetoclax/azacitidine and additional RPS6KA1 inhibition as strategy to prevent or overcome resistance.

Cyclophosphamide etoposide dexamethasone as salvage and bridging therapy in relapsed refractory and extramedullary multiple myeloma

Patients with relapsed refractory multiple myeloma (RRMM) that are triple-exposed to immunomodulatory drugs, proteasome inhibitors, and anti-CD38 monoclonal antibodies have a poor prognosis. Standard treatment for these patients has not been established. Patients with extramedullary disease or secondary plasma cell leukemia often display high tumor cell proliferation and might therefore be susceptible to chemotherapy. While current regimens are often platinum-based, we present single-center data on 70 patients with RRMM who were treated with cyclophosphamide, etoposide, and dexamethasone (CED) after a median of four lines of therapy. An overall response rate of 52% was achieved after 1-6 cycles, with 23% of patients having a very good partial response. Comparable response rates and survival were observed in patients with extramedullary disease and high-risk cytogenetics. Treatment resulted in non-hematological °III-IV adverse events in 31% of patients. No treatment-related deaths occurred. The median progression-free and overall survival were 6.2 and 10.9 months, respectively. 23% of patients were bridged to autologous stem cell transplantation (ASCT) or chimeric antigen receptor (CAR) T cell therapy. In summary, CED is an effective treatment regimen for RRMM cases with a tolerable safety profile and suitable as bridging therapy to CAR T cell treatment and ASCT.

Treatment of adult ALL patients with third-generation CD19-directed CAR T cells: results of a pivotal trial

BACKGROUND

Third-generation chimeric antigen receptor (CAR)-engineered T cells (CARTs) might improve clinical outcome of patients with B cell malignancies. This is the first report on a third-generation CART dose-escalating, phase-1/2 investigator-initiated trial treating adult patients with refractory and/or relapsed (r/r) acute lymphoblastic leukemia (ALL).

METHODS

Thirteen patients were treated with escalating doses of CD19-directed CARTs between 1 × 10⁶ and 50 × 10⁶ CARTs/m². Leukapheresis, manufacturing and administration of CARTs were performed in-house.

RESULTS

For all patients, CART manufacturing was feasible. None of the patients developed any grade of Immune effector cell-associated neurotoxicity syndrome (ICANS) or a higher-grade (≥ grade III) catokine release syndrome (CRS). CART expansion and long-term CART persistence were evident in the peripheral blood (PB) of evaluable patients. At end of study on day 90 after CARTs, ten patients were evaluable for response: Eight patients (80%) achieved a complete remission (CR), including five patients (50%) with minimal residual disease (MRD)-negative CR. Response and outcome were associated with the administered CART dose. At 1-year follow-up, median overall survival was not reached and progression-free survival (PFS) was 38%. Median PFS was reached on day 120. Lack of CD39-expression on memory-like T cells was more frequent in CART products of responders when compared to CART products of non-responders. After CART administration, higher CD8 + and γδ-T cell frequencies, a physiological pattern of immune cells and lower monocyte counts in the PB were associated with response.

CONCLUSION

In conclusion, third-generation CARTs were associated with promising clinical efficacy and remarkably low procedure-specific toxicity, thereby opening new therapeutic perspectives for patients with r/r ALL. Trial registration This trial was registered at www.

CLINICALTRIALS

gov as NCT03676504.

Five-year follow-up of a phase I trial of donor-derived modified immune cell infusion in kidney transplantation

Background

The administration of modified immune cells (MIC) before kidney transplantation led to specific immunosuppression against the allogeneic donor and a significant increase in regulatory B lymphocytes. We wondered how this approach affected the continued clinical course of these patients.

Methods

Ten patients from a phase I clinical trial who had received MIC infusions prior to kidney transplantation were retrospectively compared to 15 matched standard-risk recipients. Follow-up was until year five after surgery.

Results

The 10 MIC patients had an excellent clinical course with stable kidney graft function, no donor-specific human leukocyte antigen antibodies (DSA) or acute rejections, and no opportunistic infections. In comparison, a retrospectively matched control group receiving standard immunosuppressive therapy had a higher frequency of DSA (log rank P = 0.046) and more opportunistic infections (log rank P = 0.033). Importantly, MIC patients, and in particular the four patients who had received the highest cell number 7 days before surgery and received low immunosuppression during follow-up, continued to show a lack of anti-donor T lymphocyte reactivity in vitro and high CD19⁺CD24^hiCD38^hi transitional and CD19⁺CD24^hiCD27⁺ memory B lymphocytes until year five after surgery.

Conclusions

MIC infusions together with reduced conventional immunosuppression were associated with good graft function during five years of follow-up, no de novo DSA development and no opportunistic infections. In the future, MIC infusions might contribute to graft protection while reducing the side effects of immunosuppressive therapy. However, this approach needs further validation in direct comparison with prospective controls.

Trial registration

https://clinicaltrials.gov/, identifier NCT02560220 (for the TOL-1 Study). EudraCT Number: 2014-002086-30.

Impact of serum‑free media on the expansion and functionality of CD19.CAR T‑cells

Fetal bovine serum (FBS) or human serum is widely used in the production of chimeric antigen receptor (CAR) T‑cells. In order to overcome a lot‑to‑lot inconsistency, the use of chemically defined medium that is free of animal-components would be highly desirable. The present study compared three serum‑free media [Prime‑XV™ T Cell CDM, Fujifilm™ (FF), LymphoONE™ T‑Cell Expansion Xeno‑Free Medium, Takara Bio™ (TB) and TCM GMP‑Prototype, CellGenix™ (CG)] to the standard CAR T‑cell medium containing FBS (RCF). After 12 days of CD19.CAR T‑cell culture, the expansion, viability, transduction efficiency and phenotype were assessed using flow cytometry. The functionality of CAR T‑cells was evaluated using intracellular staining, a chromium release assay and a long‑term co‑culture assay. Expansion and viability did not differ between the CAR T‑cells generated in serum‑free media compared to the standard FBS‑containing medium. The CG CAR T‑cells had a statistically significant higher frequency of IFNγ⁺ and IFNγ⁺TNF‑α⁺ CAR T‑cells than the CAR T‑cells cultured with FBS (22.5 vs. 7.6%, P=0.0194; 15.3 vs. 6.2%, P=0.0399, respectively) as detected by intracellular cytokine staining. The CAR T‑cells generated with serum‑free media exhibited a higher cytotoxicity than the CAR T‑cells cultured with FBS in the evaluation by chromium release assay [CG vs. RCF (P=0.0182), FF vs. RCF (P=0.0482) and TB vs. RCF (P=0.0482)]. Phenotyping on day 12 of CAR T‑cell production did not reveal a significant difference in the expression of the exhaustion markers, programmed cell death protein 1, lymphocyte‑activation gene 3 and T‑cell immunoglobulin and mucin‑domain containing‑3. The CAR T‑cells cultured in FF had a higher percentage of central memory CAR T‑cells (40.0 vs. 14.3%, P=0.0470) than the CAR T‑cells cultured with FBS, whereas the CAR T‑cells in FF (6.2 vs. 24.2%, P=0.0029) and CG (11.0% vs. 24.2%, P=0.0468) had a lower frequency of naïve CAR T‑cells. On the whole, the present study demonstrates that in general, the functionality and expansion of CAR T cells are maintained in serum‑free media. Given the advantages of freedom from bovine material and consistent quality, serum‑free media hold promise for the future development of the field of GMP manufacturing of CAR T‑cells.

Reduced proliferation of bone marrow MSC after allogeneic stem cell transplantation is associated with clinical outcome

Engraftment and differentiation of donor hematopoietic stem cells is decisive for the clinical success of allogeneic stem cell transplantation (alloSCT) and depends on the recipient's bone marrow (BM) niche. A damaged niche contributes to poor graft function after alloSCT; however, the underlying mechanisms and the role of BM multipotent mesenchymal stromal cells (MSC) are ill-defined. Upon multivariate analysis in 732 individuals, we observed a reduced presence of proliferation-capable MSC in BM aspirates from patients (N = 196) who had undergone alloSCT. This was confirmed by paired analysis in 30 patients showing a higher frequency of samples with a lack of MSC presence post-alloSCT compared with pre-alloSCT. This reduced MSC presence was associated with reduced survival of patients after alloSCT and specifically with impaired graft function. Post-alloSCT MSC showed diminished in vitro proliferation along with a transcriptional antiproliferative signature, upregulation of epithelial-mesenchymal transition and extracellular matrix pathways, and altered impact on cytokine release upon contact with hematopoietic cells. To avoid in vitro culture bias, we isolated the CD146+/CD45-/HLA-DR- BM cell fraction, which comprised the entire MSC population. The post-alloSCT isolated native CD146+MSC showed a similar reduction in proliferation capacity and shared the same antiproliferative transcriptomic signature as for post-alloSCT colony-forming unit fibroblast-derived MSC. Taken together, our data show that alloSCT confers damage to the proliferative capacity of native MSC, which is associated with reduced patient survival after alloSCT and impaired engraftment of allogeneic hematopoiesis. These data represent the basis to elucidate mechanisms of BM niche reconstitution after alloSCT and its therapeutic manipulation.

Interaction of mental comorbidity and physical multimorbidity predicts length-of-stay in medical inpatients

BACKGROUND

Mental comorbidities of physically ill patients lead to higher morbidity, mortality, health-care utilization and costs.

OBJECTIVE

The aim of the study was to investigate the impact of mental comorbidity and physical multimorbidity on the length-of-stay in medical inpatients at a maximum-care university hospital.

DESIGN

The study follows a retrospective, quantitative cross-sectional analysis approach to investigate mental comorbidity and physical multimorbidity in internal medicine patients.

PATIENTS

The study comprised a total of n = 28.553 inpatients treated in 2017, 2018 and 2019 at a German Medical University Hospital.

MAIN MEASURES

Inpatients with a mental comorbidity showed a median length-of-stay of eight days that was two days longer compared to inpatients without a mental comorbidity. Neurotic and somatoform disorders (ICD-10 F4), behavioral syndromes (F5) and organic disorders (F0) were leading with respect to length-of-stay, followed by affective disorders (F3), schizophrenia and delusional disorders (F2), and substance use (F1), all above the sample mean length-of-stay. The impact of mental comorbidity on length-of-stay was greatest for middle-aged patients. Mental comorbidity and Elixhauser score as a measure for physical multimorbidity showed a significant interaction effect indicating that the impact of mental comorbidity on length-of-stay was greater in patients with higher Elixhauser scores.

CONCLUSIONS

The findings provide new insights in medical inpatients how mental comorbidity and physical multimorbidity interact with respect to length-of-stay. Mental comorbidity had a large effect on length-of-stay, especially in patients with high levels of physical multimorbidity. Thus, there is an urgent need for new service models to especially care for multimorbid inpatients with mental comorbidity.

UBTF tandem duplications are rare but recurrent alterations in adult AML and associated with younger age, myelodysplasia, and inferior outcome

Tandem-duplication mutations of the UBTF gene (UBTF-TDs) coding for the upstream binding transcription factor have recently been described in pediatric patients with acute myeloid leukemia (AML) and were found to be associated with particular genetics (trisomy 8 (+8), FLT3-internal tandem duplications (FLT3-ITD), WT1-mutations) and inferior outcome. Due to limited knowledge on UBTF-TDs in adult AML, we screened 4247 newly diagnosed adult AML and higher-risk myelodysplastic syndrome (MDS) patients using high-resolution fragment analysis. UBTF-TDs were overall rare (n = 52/4247; 1.2%), but significantly enriched in younger patients (median age 41 years) and associated with MDS-related morphology as well as significantly lower hemoglobin and platelet levels. Patients with UBTF-TDs had significantly higher rates of +8 (34% vs. 9%), WT1 (52% vs. 7%) and FLT3-ITD (50% vs. 20.8%) co-mutations, whereas UBTF-TDs were mutually exclusive with several class-defining lesions such as mutant NPM1, in-frame CEBPA^bZIP mutations as well as t(8;21). Based on the high-variant allele frequency found and the fact that all relapsed patients analyzed (n = 5) retained the UBTF-TD mutation, UBTF-TDs represent early clonal events and are stable over the disease course. In univariate analysis, UBTF-TDs did not represent a significant factor for overall or relapse-free survival in the entire cohort. However, in patients under 50 years of age, who represent the majority of UBTF-mutant patients, UBTF-TDs were an independent prognostic factor for inferior event-free (EFS), relapse-free (RFS) and overall survival (OS), which was confirmed by multivariable analyses including established risk factors such as age and ELN2022 genetic risk groups (EFS [HR: 2.20; 95% CI 1.52-3.17, p < 0.001], RFS [HR: 1.59; 95% CI 1.02-2.46, p = 0.039] and OS [HR: 1.64; 95% CI 1.08-2.49, p = 0.020]). In summary, UBTF-TDs appear to represent a novel class-defining lesion not only in pediatric AML but also younger adults and are associated with myelodysplasia and inferior outcome in these patients.

Unsupervised meta-clustering identifies risk clusters in acute myeloid leukemia based on clinical and genetic profiles

BACKGROUND

Increasingly large and complex biomedical data sets challenge conventional hypothesis-driven analytical approaches, however, data-driven unsupervised learning can detect inherent patterns in such data sets.

METHODS

While unsupervised analysis in the medical literature commonly only utilizes a single clustering algorithm for a given data set, we developed a large-scale model with 605 different combinations of target dimensionalities as well as transformation and clustering algorithms and subsequent meta-clustering of individual results. With this model, we investigated a large cohort of 1383 patients from 59 centers in Germany with newly diagnosed acute myeloid leukemia for whom 212 clinical, laboratory, cytogenetic and molecular genetic parameters were available.

RESULTS

Unsupervised learning identifies four distinct patient clusters, and statistical analysis shows significant differences in rate of complete remissions, event-free, relapse-free and overall survival between the four clusters. In comparison to the standard-of-care hypothesis-driven European Leukemia Net (ELN2017) risk stratification model, we find all three ELN2017 risk categories being represented in all four clusters in varying proportions indicating unappreciated complexity of AML biology in current established risk stratification models. Further, by using assigned clusters as labels we subsequently train a supervised model to validate cluster assignments on a large external multicenter cohort of 664 intensively treated AML patients.

CONCLUSIONS

Dynamic data-driven models are likely more suitable for risk stratification in the context of increasingly complex medical data than rigid hypothesis-driven models to allow for a more personalized treatment allocation and gain novel insights into disease biology.

Physical biomarkers for human hematopoietic stem and progenitor cells

Adhesion of hematopoietic stem and progenitor cells (HSPCs) to the bone marrow niche plays critical roles in the maintenance of the most primitive HSPCs. The interactions of HSPC-niche interactions are clinically relevant in acute myeloid leukemia (AML), because (i) leukemia-initiating cells adhered to the marrow niche are protected from the cytotoxic effect by chemotherapy and (ii) mobilization of HSPCs from healthy donors' bone marrow is crucial for the effective stem cell transplantation. However, although many clinical agents have been developed for the HSPC mobilization, the effects caused by the extrinsic molecular cues were traditionally evaluated based on phenomenological observations. This review highlights the recent interdisciplinary challenges of hematologists, biophysicists and cell biologists towards the design of defined in vitro niche models and the development of physical biomarkers for quantitative indexing of differential effects of clinical agents on human HSPCs.

Clonally resolved single-cell multi-omics identifies routes of cellular differentiation in acute myeloid leukemia

Inter-patient variability and the similarity of healthy and leukemic stem cells (LSCs) have impeded the characterization of LSCs in acute myeloid leukemia (AML) and their differentiation landscape. Here, we introduce CloneTracer, a novel method that adds clonal resolution to single-cell RNA-seq datasets. Applied to samples from 19 AML patients, CloneTracer revealed routes of leukemic differentiation. Although residual healthy and preleukemic cells dominated the dormant stem cell compartment, active LSCs resembled their healthy counterpart and retained erythroid capacity. By contrast, downstream myeloid progenitors constituted a highly aberrant, disease-defining compartment: their gene expression and differentiation state affected both the chemotherapy response and leukemia's ability to differentiate into transcriptomically normal monocytes. Finally, we demonstrated the potential of CloneTracer to identify surface markers misregulated specifically in leukemic cells. Taken together, CloneTracer reveals a differentiation landscape that mimics its healthy counterpart and may determine biology and therapy response in AML.