Unscheduled healthcare interactions in multiple myeloma patients receiving T cell redirection therapies

Outcomes for relapsed/refractory multiple myeloma (RRMM) patients have dramatically improved following the development and now growing utilization of B cell maturation antigen targeted chimeric antigen receptor (CAR) T cell therapy and bispecific antibody (BsAb) therapy. However, healthcare utilization as a quality-of-life metric in these growing populations has not been thoroughly evaluated. We performed a retrospective cohort study evaluating the frequency and cause of unscheduled healthcare interactions (UHIs) among RRMM patients responding to B-cell maturation antigen targeted BsAbs and CAR T cell therapies (N = 46). This included analysis of remote UHIs including calls to physicians' offices and messages sent through an online patient portal. Our results showed that nearly all (89%) RRMM patients receiving these therapies required a UHI during the first 125 days of treatment, with a mean of 3.7 UHIs per patient. RRMM patients responding to BsAbs were significantly more likely to remotely contact their physicians' offices (1.8-fold increase, p = 0.038) or visit an urgent care center (>3-fold increase, p = 0.012) than RRMM patients responding to CAR T cell therapies. This was largely due to increased reports of mild upper respiratory tract infections in BsAb patients. Our results underscore the need to develop preemptive management strategies for commonly reported symptoms that RRMM patients experience while receiving CAR T cell or BsAb therapies. This preemptive management may significantly reduce unnecessary healthcare utilization in this vulnerable patient population.

Patterns of CRS with Teclistamab in Relapsed/Refractory Multiple Myeloma patients with Prior T-Cell Redirection Therapy

Teclistamab (Tec) is a first-in-class BCMA X CD3 bispecific T-cell engager antibody approved for treating multiple myeloma progressing after at least 4 lines of therapy. The objective of this study was to evaluate the rate of cytokine release syndrome (CRS) in patients who were treated with commercial Tec and had prior exposure to other T-cell redirection therapies. A retrospective chart review was performed to identify patients who completed the Tec step-up dosing phase between November 2022 and November 2023. Patients were divided into 2 cohorts based on prior exposure to T-cell redirection therapy (cohort 1: T-cell redirection therapy experienced; cohort 2: T-cell redirection therapy naïve). The primary objective was to compare the differences in the rates of CRS between the two cohorts. Univariate and multivariate logistic regression analyses were performed to assess the association between CRS rates with Tec and prior treatment with T-cell redirection therapy. A total of 72 patients were included in the analysis (27 in cohort 1 and 45 in cohort 2). The CRS rates were significantly lower in cohort 1 (37%, n=10) compared to cohort 2 (80%, n=36; p=0.0004). Based on multivariate logistic regression analysis, patients without prior exposure to T-cell redirection therapy (cohort 2) had about a 4-fold increase in the incidence of CRS (95% CI: 1.40-14.90, p=0.0002) with Tec. In our study, prior exposure to T-cell redirection therapy reduced the risk of CRS with Tec during the step-up dosing phase. This observation will allow for the optimization of CRS prophylactic strategies for Tec.

CD8 effector T cells enhance teclistamab response in BCMA-exposed and -naïve multiple myeloma

ABSTRACT

Teclistamab, a B-cell maturation antigen (BCMA)- and CD3-targeting bispecific antibody, is an effective novel treatment for relapsed/refractory multiple myeloma (R/RMM), but efficacy in patients exposed to BCMA-directed therapies and mechanisms of resistance have yet to be fully delineated. We conducted a real-world retrospective study of commercial teclistamab, capturing both clinical outcomes and immune correlates of treatment response in a cohort of patients (n = 52) with advanced R/RMM. Teclistamab was highly effective with an overall response rate (ORR) of 64%, including an ORR of 50% for patients with prior anti-BCMA therapy. Pretreatment plasma cell BCMA expression levels had no bearing on response. However, comprehensive pretreatment immune profiling identified that effector CD8+ T-cell populations were associated with response to therapy and a regulatory T-cell population associated with nonresponse, indicating a contribution of immune status in outcomes with potential utility as a biomarker signature to guide patient management.

Targeting the ribosome to treat multiple myeloma

The high rates of protein synthesis and processing render multiple myeloma (MM) cells vulnerable to perturbations in protein homeostasis. The induction of proteotoxic stress by targeting protein degradation with proteasome inhibitors (PIs) has revolutionized the treatment of MM. However, resistance to PIs is inevitable and represents an ongoing clinical challenge. Our first-in-human study of the selective inhibitor of RNA polymerase I transcription of ribosomal RNA genes, CX-5461, has demonstrated a potential signal for anti-tumor activity in three of six heavily pre-treated MM patients. Here, we show that CX-5461 has potent anti-myeloma activity in PI-resistant MM preclinical models in vitro and in vivo. In addition to inhibiting ribosome biogenesis, CX-5461 causes topoisomerase II trapping and replication-dependent DNA damage, leading to G2/M cell-cycle arrest and apoptotic cell death. Combining CX-5461 with PI does not further enhance the anti-myeloma activity of CX-5461 in vivo. In contrast, CX-5461 shows synergistic interaction with the histone deacetylase inhibitor panobinostat in both the Vk∗MYC and the 5T33-KaLwRij mouse models of MM by targeting ribosome biogenesis and protein synthesis through distinct mechanisms. Our findings thus provide strong evidence to facilitate the clinical development of targeting the ribosome to treat relapsed and refractory MM.

Gene interaction network analysis in multiple myeloma detects complex immune dysregulation associated with shorter survival

The plasma cell cancer multiple myeloma (MM) varies significantly in genomic characteristics, response to therapy, and long-term prognosis. To investigate global interactions in MM, we combined a known protein interaction network with a large clinically annotated MM dataset. We hypothesized that an unbiased network analysis method based on large-scale similarities in gene expression, copy number aberration, and protein interactions may provide novel biological insights. Applying a novel measure of network robustness, Ollivier-Ricci Curvature, we examined patterns in the RNA-Seq gene expression and CNA data and how they relate to clinical outcomes. Hierarchical clustering using ORC differentiated high-risk subtypes with low progression free survival. Differential gene expression analysis defined 118 genes with significantly aberrant expression. These genes, while not previously associated with MM, were associated with DNA repair, apoptosis, and the immune system. Univariate analysis identified 8/118 to be prognostic genes; all associated with the immune system. A network topology analysis identified both hub and bridge genes which connect known genes of biological significance of MM. Taken together, gene interaction network analysis in MM uses a novel method of global assessment to demonstrate complex immune dysregulation associated with shorter survival.

Molecular Evolution of Classic Hodgkin Lymphoma Revealed Through Whole-Genome Sequencing of Hodgkin and Reed Sternberg Cells

The rarity of malignant Hodgkin and Reed Sternberg (HRS) cells in classic Hodgkin lymphoma (cHL) limits the ability to study the genomics of cHL. To circumvent this, our group has previously optimized fluorescence-activated cell sorting to purify HRS cells. Using this approach, we now report the whole-genome sequencing landscape of HRS cells and reconstruct the chronology and likely etiology of pathogenic events leading to cHL. We identified alterations in driver genes not previously described in cHL, APOBEC mutational activity, and the presence of complex structural variants including chromothripsis. We found that high ploidy in cHL is often acquired through multiple, independent chromosomal gains events including whole-genome duplication. Evolutionary timing analyses revealed that structural variants enriched for RAG motifs, driver mutations in B2M, BCL7A, GNA13, and PTPN1, and the onset of AID-driven mutagenesis usually preceded large chromosomal gains. This study provides a temporal reconstruction of cHL pathogenesis.

SIGNIFICANCE

Previous studies in cHL were limited to coding sequences and therefore not able to comprehensively decipher the tumor complexity. Here, leveraging cHL whole-genome characterization, we identify driver events and reconstruct the tumor evolution, finding that structural variants, driver mutations, and AID mutagenesis precede chromosomal gains. This article is highlighted in the In This Issue feature, p. 171.

Abstract 2061: Protein network analysis uncovers a poor-survival subtype in multiple myeloma

Multiple myeloma (MM) prognosis incorporates a variety of metrics including treatment received, clinical factors, and genomic characteristics, with several specific genomic features predicting for shorter progression free survival (PFS). No study to date has integrated genomic data from a systems view, incorporating interactions between biomarkers in a network. We use a geometric network analysis that integrates complex interactions to characterize patterns of biological behavior not captured by individual genomic events. The methodology is mathematically well-defined and has no fitting parameters. We hypothesized that such a systems mathematical approach applied to gene interaction networks may delineate biologically relevant MM subtypes and potential new therapeutic targets. We overlaid RNA-Seq and copy number alteration data from the MMRF CoMMpass study (IA19) on a gene interactome derived from the Human Protein Reference Database using a novel graph metric of network robustness — Ollivier-Ricci curvature (ORC). Results were clustered, with the optimal number determined via silhouette score. Survival analysis for PFS was performed employing Kaplan-Meier and log-rank tests. A differential gene expression analysis between high and low risk groups was conducted. Differences in scalar ORC between the low-risk and high-risk groups were examined and contextualized using a pathway analysis. Pathway analysis was performed using the Broad Institute’s Gene Set Enrichment Analysis tool and the pathways used are from the hallmark gene set from the Human MSigDB collection. The dataset included 659 patients and the incorporated protein-protein interactions resulted in a network with 8,468 nodes and 33,695 edges. The ORC analysis discovered 6 clusters, with specific genomic features being associated with clusters predicting for long [hyperdiploidy, t(11:14)], and short [t(4;14), MAF/MAFB translocations] PFS. A differential gene expression analysis comparing the high risk and low risk groups identified 118 key genes. These genes were associated with various pathways both known and unknown to be associated with multiple myeloma, including mitotic spindle, DNA repair, inflammatory response, and the P53 pathways. Further scalar curvature analysis showed differences in the apoptosis, TGF beta signaling, and other signaling pathways. In summary, we applied the geometric network analysis tool ORC to multi-omics data in MM represented as biological networks to identify individuals at high risk of short PFS and relevant biological correlates. Decreased robustness of signaling near immune-related genes was associated with shorter survival, highlighting the plausible utility of using these methods to uncover new biological insights.

Citation Format: Anish K. Simhal, Kylee H. Maclachlan, Rena Elkin, Jiening Zhu, Saad Z. Usmani, Jonathan J. Keats, Larry Norton, Joseph O. Deasy, Jung Hun Oh, Allen Tannenbaum. Protein network analysis uncovers a poor-survival subtype in multiple myeloma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2061.

Waldenström macroglobulinemia whole genome reveals prolonged germinal center activity and late copy number aberrations

The genomic landscape of Waldenström macroglobulinemia (WM) is characterized by somatic mutations in MYD88, present from the precursor stages. Using the comprehensive resolution of whole genome sequencing (WGS) in 14 CD19-selected primary WM samples; comparing clonal and subclonal mutations revealed that germinal center (GC) mutational signatures SBS9 (poly-eta) and SBS84 (AID) have sustained activity, suggesting that the interaction between WM and the GC continues over time. Expanding our cohort size with 33 targeted sequencing samples, we interrogated the WM copy number aberration (CNA) landscape and chronology. Of interest, CNA prevalence progressively increased in symptomatic WM and relapsed disease when compared with stable precursor stages, with stable precursors lacking genomic complexity. Two MYD88 wild-type WGS contained a clonal gain affecting chromosome 12, which is typically an early event in chronic lymphocytic leukemia. Molecular time analysis demonstrated that both chromosomal 12 gain events occurred early in cancer development whereas other CNA changes tend to occur later in the disease course and are often subclonal. In summary, WGS analysis in WM allows the demonstration of sustained GC activity over time and allows the reconstruction of the temporal evolution of specific genomic features. In addition, our data suggest that, although MYD88-mutations are central to WM clone establishment and can be observed in precursor disease, CNA may contribute to later phases, and may be used as a biomarker for progression risk from precursor conditions to symptomatic disease.

Sustained Minimal Residual Disease Negativity in Multiple Myeloma is Associated with Stool Butyrate and Healthier Plant-Based Diets

PURPOSE

Sustained minimal residual disease (MRD) negativity is associated with long-term survival in multiple myeloma. The gut microbiome is affected by diet, and in turn can modulate host immunity, for example through production of short-chain fatty acids including butyrate. We hypothesized that dietary factors affect the microbiome (abundance of butyrate-producing bacteria or stool butyrate concentration) and may be associated with multiple myeloma outcomes.

EXPERIMENTAL DESIGN

We examined the relationship of dietary factors (via a food frequency questionnaire), stool metabolites (via gas chromatography-mass spectrometry), and the stool microbiome (via 16S sequencing - α-diversity and relative abundance of butyrate-producing bacteria) with sustained MRD negativity (via flow cytometry at two timepoints 1 year apart) in myeloma patients on lenalidomide maintenance. The Healthy Eating Index 2015 score and flavonoid nutrient values were calculated from the food frequency questionnaire. The Wilcoxon rank sum test was used to evaluate associations with two-sided P < 0.05 considered significant.

RESULTS

At 3 months, higher stool butyrate concentration (P = 0.037), butyrate producers (P = 0.025), and α-diversity (P = 0.0035) were associated with sustained MRD negativity. Healthier dietary proteins, (from seafood and plants), correlated with butyrate at 3 months (P = 0.009) and sustained MRD negativity (P = 0.05). Consumption of dietary flavonoids, plant nutrients with antioxidant effects, correlated with stool butyrate concentration (anthocyanidins P = 0.01, flavones P = 0.01, and flavanols P = 0.02).

CONCLUSIONS

This is the first study to demonstrate an association between a plant-based dietary pattern, stool butyrate production, and sustained MRD negativity in multiple myeloma, providing rationale to evaluate a prospective dietary intervention.

Are we ready to look beyond plasma cells in assessing high-risk smoldering myeloma?

Sklavenitis-Pistofidis et al. report clinical and correlative results of a single-arm phase II trial of elotuzumab, lenalidomide, and dexamethasone in patients with high-risk smoldering myeloma. The authors explore the interactions between the genetics of the plasma cell clone and the immune microenvironment as potential biomarkers of treatment susceptibility and efficacy.

Copy number signatures predict chromothripsis and clinical outcomes in newly diagnosed multiple myeloma

Chromothripsis is detectable in 20–30% of newly diagnosed multiple myeloma (NDMM) patients and is emerging as a new independent adverse prognostic factor. In this study we interrogate 752 NDMM patients using whole genome sequencing (WGS) to investigate the relationship of copy number (CN) signatures to chromothripsis and show they are highly associated. CN signatures are highly predictive of the presence of chromothripsis (AUC = 0.90) and can be used identify its adverse prognostic impact. The ability of CN signatures to predict the presence of chromothripsis is confirmed in a validation series of WGS comprised of 235 hematological cancers (AUC = 0.97) and an independent series of 34 NDMM (AUC = 0.87). We show that CN signatures can also be derived from whole exome data (WES) and using 677 cases from the same series of NDMM, we are able to predict both the presence of chromothripsis (AUC = 0.82) and its adverse prognostic impact. CN signatures constitute a flexible tool to identify the presence of chromothripsis and is applicable to WES and WGS data.

Chromothripsis is associated with unfavourable outcomes in multiple myeloma (MM), but its detection usually requires whole genome sequencing. Here the authors develop an approach to detect chromothripsis in MM based on copy-number signatures that also works with whole exome sequencing data.

Minimal residual disease in multiple myeloma: defining the role of next generation sequencing and flow cytometry in routine diagnostic use

For patients diagnosed with multiple myeloma (MM) there have been significant treatment advances over the past decade, reflected in an increasing proportion of patients achieving durable remissions. Clinical trials repeatedly demonstrate that achieving a deep response to therapy, with a bone marrow assessment proving negative for minimal residual disease (MRD), confers a significant survival advantage. To accurately assess for minute quantities of residual cancer requires highly sensitive methods; either multiparameter flow cytometry or next generation sequencing are currently recommended for MM response assessment. Under optimal conditions, these methods can detect one aberrant cell amongst 1,000,000 normal cells (a sensitivity of 10^-6). Here, we will review the practical use of MRD assays in MM, including challenges in implementation for the routine diagnostic laboratory, standardisation across laboratories and clinical trials, the clinical integration of MRD status assessment into MM management and future directions for ongoing research.

Initial Whole-Genome Sequencing of Plasma Cell Neoplasms in First Responders and Recovery Workers Exposed to the World Trade Center Attack of September 11, 2001

PURPOSE

The World Trade Center (WTC) attack of September 11, 2001 created an unprecedented environmental exposure to known and suspected carcinogens. High incidence of multiple myeloma and precursor conditions has been reported among first responders to the WTC disaster. To expand on our prior screening studies, and to characterize the genomic impact of the exposure to known and potential carcinogens in the WTC debris, we were motivated to perform whole-genome sequencing (WGS) of WTC first responders and recovery workers who developed a plasma cell disorder after the attack.

EXPERIMENTAL DESIGN

We performed WGS of nine CD138-positive bone marrow mononuclear samples from patients who were diagnosed with plasma cell disorders after the WTC disaster.

RESULTS

No significant differences were observed in comparing the post-WTC driver and mutational signature landscapes with 110 previously published WGSs from 56 patients with multiple myeloma and the CoMMpass WGS cohort (n = 752). Leveraging constant activity of the single-base substitution mutational signatures 1 and 5 over time, we estimated that tumor-initiating chromosomal gains were windowed to both pre- and post-WTC exposure.

CONCLUSIONS

Although limitations in sample size preclude any definitive conclusions, our findings suggest that the observed increased incidence of plasma cell neoplasms in this population is due to complex and heterogeneous effects of the WTC exposure that may have initiated or contributed to progression of malignancy.

Revealing the impact of structural variants in multiple myeloma

The landscape of structural variants (SVs) in multiple myeloma remains poorly understood. Here, we performed comprehensive analysis of SVs in a large cohort of 752 multiple myeloma patients by low coverage long-insert whole genome sequencing. We identified 68 SV hotspots involving 17 new candidate driver genes, including the therapeutic targets BCMA (TNFRSF17), SLAMF and MCL1. Catastrophic complex rearrangements termed chromothripsis were present in 24% of patients and independently associated with poor clinical outcomes. Templated insertions were the second most frequent complex event (19%), mostly involved in super-enhancer hijacking and activation of oncogenes such as CCND1 and MYC. Importantly, in 31% of patients two or more seemingly independent putative driver events were caused by a single structural event, demonstrating that the complex genomic landscape of multiple myeloma can be acquired through few key events during tumor evolutionary history. Overall, this study reveals the critical role of SVs in multiple myeloma pathogenesis.

Accelerated single cell seeding in relapsed multiple myeloma

Multiple myeloma (MM) progression is characterized by the seeding of cancer cells in different anatomic sites. To characterize this evolutionary process, we interrogated, by whole genome sequencing, 25 samples collected at autopsy from 4 patients with relapsed MM and an additional set of 125 whole exomes collected from 51 patients. Mutational signatures analysis showed how cytotoxic agents introduce hundreds of unique mutations in each surviving cancer cell, detectable by bulk sequencing only in cases of clonal expansion of a single cancer cell bearing the mutational signature. Thus, a unique, single-cell genomic barcode can link chemotherapy exposure to a discrete time window in a patient′s life. We leveraged this concept to show that MM systemic seeding is accelerated at relapse and appears to be driven by the survival and subsequent expansion of a single myeloma cell following treatment with high-dose melphalan therapy and autologous stem cell transplant.

In multiple myeloma, disease progresses via seeding to different anatomic sites and clonal expansion. Here, utilising autopsy material, the authors show that systemic seeding accelerates at relapse following treatment.

First-in-Human RNA Polymerase I Transcription Inhibitor CX-5461 in Patients with Advanced Hematologic Cancers: Results of a Phase I Dose-Escalation Study

RNA polymerase I (Pol I) transcription of ribosomal RNA genes (rDNA) is tightly regulated downstream of oncogenic pathways, and its dysregulation is a common feature in cancer. We evaluated CX-5461, the first-in-class selective rDNA transcription inhibitor, in a first-in-human, phase I dose-escalation study in advanced hematologic cancers. Administration of CX-5461 intravenously once every 3 weeks to 5 cohorts determined an MTD of 170 mg/m², with a predictable pharmacokinetic profile. The dose-limiting toxicity was palmar-plantar erythrodysesthesia; photosensitivity was a dose-independent adverse event (AE), manageable by preventive measures. CX-5461 induced rapid on-target inhibition of rDNA transcription, with p53 activation detected in tumor cells from one patient achieving a clinical response. One patient with anaplastic large cell lymphoma attained a prolonged partial response and 5 patients with myeloma and diffuse large B-cell lymphoma achieved stable disease as best response. CX-5461 is safe at doses associated with clinical benefit and dermatologic AEs are manageable. SIGNIFICANCE: CX-5461 is a first-in-class selective inhibitor of rDNA transcription. This first-in-human study establishes the feasibility of targeting this process, demonstrating single-agent antitumor activity against advanced hematologic cancers with predictable pharmacokinetics and a safety profile allowing prolonged dosing. Consistent with preclinical data, antitumor activity was observed in TP53 wild-type and mutant malignancies.This article is highlighted in the In This Issue feature, p. 983.