Binder, Moritz

Abstract Extramedullary disease (EMD) is associated with an inferior prognosis and lower response rates to conventional multiple myeloma (MM)–directed therapies compared to MM without EMD. A deeper understanding of the molecular landscape and underlying drivers of EMD is essential to identify potential targets for novel therapeutic strategies. To address this, we performed whole-exome sequencing on EMD tumor tissue from 18 unique patients and bone marrow aspirates (BMAs) from 20 patients at the time of EMD development. Notably, paired EMD and BMA samples were collected from 6 patients at the point of EMD diagnosis, allowing for direct comparison of molecular profiles. Our analysis revealed a near-universal presence of mutations within the MAPK pathway in EMD samples (94%), compared to BMAs (60%; odds ratio, 10.7; P = .02; q < 0.1). Additionally, mutations in established driver genes (NRAS, KRAS, and BRAF) were common and frequently clonal, suggesting their central role in EMD pathogenesis. We also identified alterations in genes associated with cell adhesion and migration (ROBO1, ROBO2, and FAT1) and the SWI/SNF complex and epigenetic regulators (ARID1A, KMT2C, KMT2D, and EP300), although these were predominantly subclonal. Furthermore, we frequently detected biallelic alterations in the tumor suppressor genes MAX (22%), a binding partner for MYC, and CDKN2C (17%). Genomic complexity was significantly higher in EMD samples than BMAs, as evidenced by increased tumor mutational burden and the enrichment of 1q gain/amplifications. These findings underscore the distinct molecular profile of EMD compared to BMA and highlight the genomically complex and heterogeneous nature of extramedullary disease in MM.

PURPOSE Cytokine release syndrome (CRS) of any grade occurs in 56%-80% of bispecific antibodies (BsAbs) used in multiple myeloma (MM). Risk mitigation strategies are required to expedite escalation of care if toxicities develop. The rarity of grade 3 or 4 CRS compels protocolized outpatient management of BsAbs as outpatient practice may avoid hospital admissions and costly resource utilization without compromising safety. MATERIALS AND METHODS Patients with MM who received BsAb step-up dosing (SUD) from August 23, 2023, to March 29, 2024, were enrolled. Baseline demographics, patient outcomes, and CRS management were reviewed to assess the safety of outpatient practice. Resource utilization was also analyzed. RESULTS In this study, 34 patients received outpatient SUD of BsAbs (teclistamab n = 17, talequetamab n = 17) with 16 remaining outpatient throughout the entire SUD period. CRS occurred in seven patients who did not require hospitalization, demonstrating the safety of outpatient management of BsAb toxicity, regardless of low-grade CRS. CRS was observed in 24 patients (maximum grade 2) and immune effector cell–associated neurotoxicity syndrome in four patients (maximum grade 3). All patients with CRS received steroids, including 12 patients at home when instructed. Tocilizumab was given to 13 patients, accounting for 18 doses. If all doses of BsAbs and tocilizumab were given outpatient, the medication margin would be $115,004 in US dollars (USD). CONCLUSION An outpatient-based practice for BsAb administration demonstrated safety and cost savings. The description of our practice and results of this study provide valuable insights into the safety, feasibility, and resource stewardship of outpatient management of BsAbs. Future research should attempt to predict and stratify CRS risk to deliver a tailored supportive strategy and continued increase of outpatient management.

Abstract Multiple myeloma (MM) is a complex hematological malignancy characterized by genomic changes and transcriptomic dysregulation. Initial exome sequencing approaches have failed to identify any single, frequent (>25%) mutation in the coding genome. However, using whole-genome sequencing, we found that one of the genomic regions most frequently mutated (62% of the patients with MM) was the 5′ untranslated region and/or intron 1 of the BCL7A gene. RNA-sequencing data from a large cohort suggest a loss of BCL7A expression in a large majority of patients with MM as compared with normal plasma cells. BCL7A loss of function in a panel of MM cell lines led to a highly proliferative phenotype in vitro and in vivo, whereas its ectopic expression significantly reduced cell viability, suggesting a tumor suppressor function for BCL7A in MM. We studied the cellular and molecular effects of BCL7A loss and observed that it endows myeloma cells with proliferative potential in cooperation with the plasma cell–defining transcription factor IRF4. BCL7A is involved in a direct protein-protein interaction with IRF4, limiting its DNA-binding activity. Loss of BCL7A thus enhances the expression of IRF4-associated cytokines and reduces mitochondrial metabolism and reactive oxygen species levels. Our study therefore suggests that BCL7A loss provides the necessary molecular change to allow IRF4-mediated transcriptional activity and MM cell growth and survival.

Abstract In this study, we first analyzed data from 147 patients with solitary plasmacytomas treated at the Mayo Clinic between 2005 and 2022 and then expanded our investigation through a systematic review and meta-analysis of 62 studies, encompassing 3487 patients from the years 1960 to 2022. Our findings reveal that patients with up to 10% clonal plasma cells in their bone marrow (BM), denoted as plasmacytoma +, had a significantly reduced median disease-free survival (DFS) of 15.7 months vs 79 months, P < .05, observed in patients with true solitary plasmacytomas, with no clonal cells in the BM. Risk factors identified for shorter DFS included the presence of clonal plasma cells in the marrow and a difference between involved and uninvolved free light chains of >5 mg/dL. The meta-analysis portion of our study highlighted a male predominance among patients, with a median age of 58 years, and confirmed radiation therapy as the predominant treatment modality. We also found that DFS rates at 3, 5, and 10 years were 66.9%, 55%, and 42.1%, respectively, and noted a significant difference in outcomes between patients with bone and extramedullary plasmacytomas, with the latter group exhibiting better survival rates. This dual-faceted approach provides a thorough overview of survival rates and critical risk factors for patients with plasmacytoma, underscoring the vital role of accurate disease staging at diagnosis and the impact of tumor location on patient prognosis.

ASXL transcriptional regulator 1 (ASXL1) is one of the three most frequently mutated genes in age-related clonal hematopoiesis (CH), alongside DNA methyltransferase 3 alpha (DNMT3A) and Tet methylcytosine dioxygenase 2 ( TET2) . CH can progress to myeloid malignancies including chronic monomyelocytic leukemia (CMML) and is also strongly associated with inflammatory cardiovascular disease and all-cause mortality in humans. DNMT3A and TET2 regulate DNA methylation and demethylation pathways, respectively, and loss-of-function mutations in these genes reduce DNA methylation in heterochromatin, allowing derepression of silenced elements in heterochromatin. In contrast, the mechanisms that connect mutant ASXL1 and CH are not yet fully understood. CH/CMML-associated ASXL1 mutations encode C-terminally truncated proteins that enhance the deubiquitinase activity of the ASXL-BAP1 “PR-DUB” deubiquitinase complex, which removes monoubiquitin from H2AK119Ub. Here, we show that ASXL1 mutant proteins interact with the euchromatic histone lysine methyltransferases 1 and 2 (EHMT1–EHMT2) complex, which generates H3K9me1 and me2, the latter a repressive modification in constitutive heterochromatin. Compared to cells from age-matched wild-type mice, we found that expanded myeloid cells from old (≥18-mo-old) Asxl1tm/+ mice, a heterozygous knock-in mouse model of CH, display genome-wide decreases of H3K9me2, H3K9me3, and H2AK119Ub as well as an associated increase in expression of transposable elements (TEs) and satellite repeats. Increased TE expression was also observed in monocytes from ASXL1 -mutant CMML patients compared to monocytes from healthy controls. Our data suggest that mutant ASXL1 proteins compromise the integrity of both constitutive and facultative heterochromatin in an age-dependent manner by reducing the levels of H3K9me2/3 and H2AK119Ub. This increase in TE expression correlated with increased expression of nearby genes, including many interferon-inducible (inflammation-associated) genes (ISGs).

Abstract Patient-reported outcomes (PROs) are associated with treatment outcomes in multiple myeloma (MM) in the clinical trial setting. However, most PRO tools are time consuming, which hinders use in routine practice. Our institution incorporated a “Hematology Patient-Reported Symptom Screen” (HPRSS), a 3-item questionnaire for fatigue, pain, and quality of life (QOL). The main objective of this study was to evaluate the impact of these symptoms on progression-free survival (PFS) and overall survival (OS) in a real-world cohort of patients with newly diagnosed MM. This retrospective study included patients with MM diagnosed between April 2011 and December 2017, seen at Mayo Clinic (Rochester, MN), who completed the HPRSS. Patients rated their symptoms on a scale from 0 to 10. Clinically relevant symptoms were defined as scores ≥5 for pain and fatigue, and ≤5 for QOL. At diagnosis, 735 patients had scores for all domains. The median follow-up was 8.1 years. Age was associated with increased odds of fatigue and decreased QOL. Female sex and comorbidities were associated with fatigue and pain. Higher disease stage, anemia, lytic lesions, and increased plasma cell burden were associated with fatigue, pain, and decreased QOL. Clinically relevant fatigue, pain, and decreased QOL were associated with decreased PFS and OS. On multivariate analysis including age, International Staging System III, high-risk cytogenetics, and postinduction transplantation, fatigue and decreased QOL were independently associated with decreased OS. A composite HPRSS score stratified patients into 3 groups with distinct OS. Patient-reported symptoms are prognostic in patients with newly diagnosed MM. The prognostic values of fatigue and decreased QOL are independent of age, disease stage, and transplant status.

Abstract DNMT3A and TET2 are epigenetic regulator genes commonly mutated in age-related clonal hematopoiesis (CH). Despite having opposed epigenetic functions, these mutations are associated with increased all-cause mortality and a low risk for progression to hematologic neoplasms. Although individual impacts on the epigenome have been described using different model systems, the phenotypic complexity in humans remains to be elucidated. Here, we make use of a natural inflammatory response occurring during coronavirus disease 2019 (COVID-19), to understand the association of these mutations with inflammatory morbidity (acute respiratory distress syndrome [ARDS]) and mortality. We demonstrate the age-independent, negative impact of DNMT3A mutant (DNMT3Amt) CH on COVID-19–related ARDS and mortality. Using single-cell proteogenomics we show that DNMT3A mutations involve myeloid and lymphoid lineage cells. Using single-cell multiomics sequencing, we identify cell-specific gene expression changes associated with DNMT3A mutations, along with significant epigenomic deregulation affecting enhancer accessibility, resulting in overexpression of interleukin-32 (IL-32), a proinflammatory cytokine that can result in inflammasome activation in monocytes and macrophages. Finally, we show with single-cell resolution that the loss of function of DNMT3A is directly associated with increased chromatin accessibility in mutant cells. Hence, we demonstrate the negative prognostic impact of DNMT3Amt CH on COVID-19–related ARDS and mortality. DNMT3Amt CH in the context of COVID-19, was associated with inflammatory transcriptional priming, resulting in overexpression of IL32. This overexpression was secondary to increased chromatic accessibility, specific to DNMT3Amt CH cells. DNMT3Amt CH can thus serve as a potential biomarker for adverse outcomes in COVID-19.

Abstract As patients with relapsed/refractory multiple myeloma (RRMM) continue to live longer, they might get exposed to most available drugs and drug classes during the disease course. For such late line RRMM or among patients without access to novel therapies, retreatment with a drug that the disease had previously been refractory to might be one option. In this retrospective study, we describe 315 patients with RRMM at our institution who were retreated with a drug that the disease had been previously refractory to. We found an overall response rate of 56.2% and a median progression-free survival (PFS) of 11 months with retreatment. Patients with a longer time on initial therapy with the index drug (>28.4 months) had a superior PFS with retreatment (median PFS, 16.9 vs 8.1 months; P < .001). Similarly, patients with a longer time gap between the initial line of therapy with index drug and retreatment with index drug (>46.1 months) had better PFS with retreatment (28.2 vs 8.9 months; P = .016). In conclusion, retreatment with a previously refractory drug is a viable therapeutic option for RRMM, with the most significant benefit derived in disease demonstrating sensitivity to initial drug exposure and among those with a longer gap between initial drug exposure and retreatment.

Abstract TET2 mutations (mTET2) are common genetic events in myeloid malignancies and clonal hematopoiesis. These mutations arise in the founding clone and are implicated in many clinical sequelae associated with oncogenic feedforward inflammatory circuits. However, the direct downstream effector of mTET2 responsible for the potentiation of these inflammatory circuits is unknown. To address this, we performed scRNA-seq and scATAC-seq in patients with COVID-19 with and without TET2-mutated clonal hematopoiesis reasoning that inflammation from COVID-19 may highlight critical downstream transcriptional targets of mTET2. Using this approach, we identified metastasis-associated lung adenoma transcript 1 (MALAT1), a therapeutically tractable lncRNA, as a central downstream effector of mTET2 that is both necessary and sufficient to induce the oncogenic proinflammatory features of mTET2 in vivo. We also elucidate the mechanism by which mTET2 upregulate MALAT1 and describe an interaction between MALAT1 and p65, which leads to RNA “shielding” from protein phosphatase 2A dephosphorylation, thus preventing resolution of inflammatory signaling. Significance: This work identifies MALAT1 as a requisite downstream effector of oncogenic feedforward inflammatory circuits necessary for the development of TET2-mutated CH and fulminant myeloid malignancy. We elucidate a novel mechanism by which MALAT1 “shields” p65 from dephosphorylation to potentiate this circuit and nominate MALAT1 inhibition as a future therapeutic strategy.