ABSTRACT
Adoptive T cell therapy is a promising therapy for multiple myeloma (MM), but its efficacy hinges on understanding relevant biological and predictive markers of response. B cell maturation antigen (BCMA) is a key target antigen in MM, with active development of multiple anti-BCMA T cell engagers (TCE) and chimeric antigen receptor T cell (CAR T) therapies. The regulation of surface BCMA expression by MM cells, resulting in the shedding of soluble BCMA (sBCMA), has triggered debate surrounding the significance of sBCMA as a predictive marker and its potential impact on treatment outcomes. In order to address this, we leveraged whole genome sequencing and in vitro assays to demonstrate that sBCMA may independently predict primary refractoriness to anti-BCMA therapies. In addition to sBCMA, tumor burden and surface BCMA antigen density collectively influence anti-BCMA TCE cytotoxic efficacy. Correlative analyses of 163 patients treated with anti-BCMA TCE teclistamab validated and further underscored the association between elevated baseline sBCMA (>400 ng/mL) and refractoriness. Importantly, increasing TCE dose, the use of TCE against alternative targets (e.g.,GPRC5D), or gamma secretase inhibitors were able to overcome high sBCMA. These findings highlight the importance of accounting for baseline sBCMA levels, disease burden, and TCE dose intensity when administering anti-BCMA TCEs, offering critical insights for optimizing therapeutic strategies to overcome specific high-risk features and primary anti-BCMA TCE refractoriness.
ABSTRACT
ABSTRACT: Acquisition of a hyperdiploid (HY) karyotype or immunoglobulin heavy chain (IgH) translocations are considered key initiating events in multiple myeloma (MM). To explore if other genomic events can precede these events, we analyzed whole-genome sequencing data from 1173 MM samples. By integrating molecular time and structural variants within early chromosomal duplications, we indeed identified pregain deletions in 9.4% of patients with an HY karyotype without IgH translocations, challenging acquisition of an HY karyotype as the earliest somatic event. Remarkably, these deletions affected tumor suppressor genes (TSGs) and/or oncogenes in 2.4% of patients with an HY karyotype without IgH translocations, supporting their role in MM pathogenesis. Furthermore, our study points to postgain deletions as novel driver mechanisms in MM. Using multiomics approaches to investigate their biologic impact, we found associations with poor clinical outcome in newly diagnosed patients and profound effects on both the oncogene and TSG activity despite the diploid gene status. Overall, this study provides novel insights into the temporal dynamics of genomic alterations in MM.
Subject(s)
Multiple Myeloma , Humans , Multiple Myeloma/genetics , Translocation, Genetic , Immunoglobulin Heavy Chains/genetics , Chromosome Aberrations , Gene Deletion , Male , Female , Genes, Tumor SuppressorABSTRACT
Patients treated with cytotoxic therapies, including autologous stem cell transplantation, are at risk for developing therapy-related myeloid neoplasms (tMN). Preleukemic clones (ie, clonal hematopoiesis [CH]) are detectable years before the development of these aggressive malignancies, although the genomic events leading to transformation and expansion are not well defined. Here, by leveraging distinctive chemotherapy-associated mutational signatures from whole-genome sequencing data and targeted sequencing of prechemotherapy samples, we reconstructed the evolutionary life-history of 39 therapy-related myeloid malignancies. A dichotomy was revealed, in which neoplasms with evidence of chemotherapy-induced mutagenesis from platinum and melphalan were hypermutated and enriched for complex structural variants (ie, chromothripsis), whereas neoplasms with nonmutagenic chemotherapy exposures were genomically similar to de novo acute myeloid leukemia. Using chemotherapy-associated mutational signatures as temporal barcodes linked to discrete clinical exposure in each patient's life, we estimated that several complex events and genomic drivers were acquired after chemotherapy was administered. For patients with prior multiple myeloma who were treated with high-dose melphalan and autologous stem cell transplantation, we demonstrate that tMN can develop from either a reinfused CH clone that escapes melphalan exposure and is selected after reinfusion, or from TP53-mutant CH that survives direct myeloablative conditioning and acquires melphalan-induced DNA damage. Overall, we revealed a novel mode of tMN progression that is not reliant on direct mutagenesis or even exposure to chemotherapy. Conversely, for tMN that evolve under the influence of chemotherapy-induced mutagenesis, distinct chemotherapies not only select preexisting CH but also promote the acquisition of recurrent genomic drivers.
Subject(s)
Antineoplastic Agents , Hematopoietic Stem Cell Transplantation , Leukemia, Myeloid, Acute , Neoplasms, Second Primary , Humans , Melphalan , Hematopoietic Stem Cell Transplantation/adverse effects , Transplantation, Autologous/adverse effects , Leukemia, Myeloid, Acute/drug therapy , Leukemia, Myeloid, Acute/genetics , Leukemia, Myeloid, Acute/pathology , Neoplasms, Second Primary/chemically induced , Neoplasms, Second Primary/genetics , Antineoplastic Agents/pharmacologyABSTRACT
CD19-directed chimeric antigen receptor (CAR-19) T cells are groundbreaking immunotherapies approved for use against large B-cell lymphomas. Although host inflammatory and tumor microenvironmental markers associate with efficacy and resistance, the tumor-intrinsic alterations underlying these phenomena remain undefined. CD19 mutations associate with resistance but are uncommon, and most patients with relapsed disease retain expression of the wild-type receptor, implicating other genomic mechanisms. We therefore leveraged the comprehensive resolution of whole-genome sequencing to assess 51 tumor samples from 49 patients with CAR-19-treated large B-cell lymphoma. We found that the pretreatment presence of complex structural variants, APOBEC mutational signatures, and genomic damage from reactive oxygen species predict CAR-19 resistance. In addition, the recurrent 3p21.31 chromosomal deletion containing the RHOA tumor suppressor was strongly enriched in patients for whom CAR T-cell therapy failed. Pretreatment reduced expression or monoallelic loss of CD19 did not affect responses, suggesting CAR-19 therapy success and resistance are related to multiple mechanisms. Our study showed that tumor-intrinsic genomic alterations are key among the complex interplay of factors that underlie CAR-19 efficacy and resistance for large B-cell lymphomas.
Subject(s)
Lymphoma, Large B-Cell, Diffuse , Receptors, Chimeric Antigen , Antigens, CD19 , Genomics , Humans , Immunotherapy, Adoptive , Lymphoma, Large B-Cell, Diffuse/genetics , Lymphoma, Large B-Cell, Diffuse/therapy , Receptors, Antigen, T-Cell/genetics , T-Lymphocytes , Treatment FailureABSTRACT
Alterations in KRAS have been identified as the most recurring somatic variants in the multiple myeloma (MM) mutational landscape. Combining DNA and RNA sequencing, we studied 756 patients and observed KRAS as the most frequently mutated gene in patients at diagnosis; in addition, we demonstrated the persistence or de novo occurrence of the KRAS aberration at disease relapse. Small-molecule inhibitors targeting KRAS have been developed; however, they are selective for tumors carrying the KRASG12C mutation. Therefore, there is still a need to develop novel therapeutic approaches to target the KRAS mutational events found in other tumor types, including MM. We used AZD4785, a potent and selective antisense oligonucleotide that selectively targets and downregulates all KRAS isoforms, as a tool to dissect the functional sequelae secondary to KRAS silencing in MM within the context of the bone marrow niche and demonstrated its ability to significantly silence KRAS, leading to inhibition of MM tumor growth, both in vitro and in vivo, and confirming KRAS as a driver and therapeutic target in MM.
Subject(s)
Multiple Myeloma/drug therapy , Multiple Myeloma/genetics , Mutation/drug effects , Oligonucleotides, Antisense/pharmacology , Proto-Oncogene Proteins p21(ras)/genetics , Animals , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , Cell Line, Tumor , Humans , Mice, SCID , Molecular Targeted Therapy , Neoplasm Recurrence, Local/drug therapy , Neoplasm Recurrence, Local/genetics , Oligonucleotides, Antisense/therapeutic use , Small Molecule Libraries/pharmacology , Small Molecule Libraries/therapeutic useABSTRACT
PURPOSE: Whole-genome sequencing (WGS) of patients with newly diagnosed multiple myeloma (NDMM) has shown recurrent structural variant (SV) involvement in distinct regions of the genome (i.e., hotspots) and causing recurrent copy-number alterations. Together with canonical immunoglobulin translocations, these SVs are recognized as "recurrent SVs." More than half of SVs were not involved in recurrent events. The significance of these "rare SVs" has not been previously examined. EXPERIMENTAL DESIGN: In this study, we utilize 752 WGS and 591 RNA sequencing data from patients with NDMM to determine the role of rare SVs in myeloma pathogenesis. RESULTS: Ninety-four percent of patients harbored at least one rare SV event. Rare SVs showed an SV class-specific enrichment within genes and superenhancers associated with outlier gene expression. Furthermore, known myeloma driver genes recurrently impacted by point mutations were dysregulated by rare SVs. CONCLUSIONS: Overall, we demonstrate the association of rare SVs with aberrant gene expression supporting a potential driver role in myeloma pathogenesis.
Subject(s)
Multiple Myeloma , Humans , Multiple Myeloma/diagnosis , Multiple Myeloma/genetics , Genome, Human , DNA Copy Number Variations , Whole Genome Sequencing , Translocation, GeneticABSTRACT
Intravascular large B-cell lymphoma (IVLBCL) is a rare aggressive extranodal non-Hodgkin lymphoma. The predominant, if not exclusive, growth of neoplastic cells within the lumina of small-sized vessels represents the hallmark of the disease. Diagnosis is challenging due to the absence of marked lymphadenopathy, the highly heterogeneous clinical presentation, and the rarity of the condition. Clinical presentation is characterized by variable combinations of nonspecific signs and symptoms (such as fever and weight loss), organ-specific focal manifestations due to altered perfusion, and hemophagocytic syndrome. The rarity of this entity and the paucity of neoplastic cells in biopsy samples hamper the study of recurrent molecular abnormalities. The purpose of this study was to explore the feasibility of a different approach to recover a sufficient amount of DNA of acceptable quality to perform next-generation sequencing studies. Here, we report the findings of whole-exome next-generation sequencing performed on a fresh-frozen cutaneous sample of IVLBCL, paired with the patient saliva used as germline DNA. To increase the cancer cell fraction, only the subcutaneous tissue was selected. With this approach, we obtained high-quality DNA and were able to identify oncogenic mutations specific for this entity and recapitulating its post-germinal center origin, even if the tumor fraction was low. Molecular studies performed on fresh-frozen cutaneous sample are feasible in IVLBCL, especially when analysis is restricted to the subcutaneous tissue. Wide adoption of this reproducible and cost-effective approach may foster further studies, which may be of help in supporting diagnosis, providing pathogenetic insights, and guiding treatment decisions.
Subject(s)
Lymphoma, Large B-Cell, Diffuse , Lymphoma, Non-Hodgkin , Humans , Exome Sequencing , Lymphoma, Large B-Cell, Diffuse/diagnosis , Lymphoma, Large B-Cell, Diffuse/genetics , Subcutaneous Tissue , DNAABSTRACT
Recent data highlight genomic events driving antigen escape as a recurring cause of chimeric antigen receptor T-cell (CAR-T) and bispecific T-cell engager (TCE) resistance in multiple myeloma (MM). Yet, it remains unclear if these events, leading to clonal dominance at progression, result from acquisition under treatment selection or selection of pre-existing undetectable clones. This differentiation gains importance as these immunotherapies progress to earlier lines of treatment, prompting the need for innovative diagnostic testing to detect these events early on. By reconstructing phylogenetic trees and exploring chemotherapy mutational signatures as temporal barcodes in 11 relapsed refractory MM patients with available whole genome sequencing data before and after CART/TCE treatment, we demonstrated that somatic antigen escape mechanisms for BCMA- and GPRC5D-targeting therapies are acquired post-diagnosis, likely during CART/TCE treatment. Longitudinal tracking of these mutations using digital PCR in 4 patients consistently showed that genomic events promoting antigen escape were not detectable during the initial months of therapy but began to emerge nearly 1 year post therapy initiation. This finding reduces the necessity for a diagnostic panel to identify these events before CART/TCE. Instead, it underscores the importance of surveillance and identifying patients at higher risk of acquiring these events.
ABSTRACT
PURPOSE: Early intervention for high-risk smoldering multiple myeloma (HR-SMM) achieves deep and prolonged responses. It is unclear if beneficial outcomes are due to the treatment of less complex, susceptible disease or inaccuracy in clinical definition of cases entered. EXPERIMENTAL DESIGN: In this study, we interrogated whole-genome and whole-exome sequencing for 54 patients across two HR-SMM interventional studies (NCT01572480 and NCT02279394). RESULTS: We reveal that the genomic landscape of treated HR-SMM is generally simple as compared with newly diagnosed multiple myeloma counterparts with less inactivation of tumor suppressor genes, RAS pathway mutations, MYC disruption, and APOBEC contribution. The absence of these events parallels that of indolent precursor conditions, possibly explaining overall excellent outcomes. However, some patients harboring genomic complexity fail to sustain response and experience resistant, progressive disease. Overall, clinical risk scores do not effectively discriminate between genomically indolent and aggressive disease. CONCLUSIONS: Genomic profiling can contextualize the advantage of early intervention in SMM and guide personalization of therapy. See related commentary by Weinhold and Rasche, p. 4263.
Subject(s)
Genomics , Mutation , Smoldering Multiple Myeloma , Humans , Smoldering Multiple Myeloma/genetics , Smoldering Multiple Myeloma/diagnosis , Smoldering Multiple Myeloma/therapy , Genomics/methods , Exome Sequencing , Female , Male , Middle Aged , Aged , Biomarkers, Tumor/genetics , Multiple Myeloma/genetics , Multiple Myeloma/therapy , Multiple Myeloma/pathology , Whole Genome Sequencing , Gene Expression ProfilingABSTRACT
Targeted immunotherapy combinations, including the anti-CD38 monoclonal antibody (MoAb) daratumumab, have shown promising results in patients with relapsed/refractory multiple myeloma (RRMM), leading to a considerable increase in progression-free survival. However, a large fraction of patients inevitably relapse. To understand this, we investigated 32 relapsed MM patients treated with daratumumab, lenalidomide, and dexamethasone (Dara-Rd; NCT03848676). We conducted an integrated analysis using whole-genome sequencing (WGS) and flow cytometry in patients with RRMM. WGS before and after treatment pinpointed genomic drivers associated with early progression, including RPL5 loss, APOBEC mutagenesis, and gain of function structural variants involving MYC and chromothripsis. Flow cytometry on 202 blood samples, collected every 3 months until progression for 31 patients, revealed distinct immune changes significantly impacting clinical outcomes. Progressing patients exhibited significant depletion of CD38-positive NK cells, persistence of T-cell exhaustion, and reduced depletion of regulatory T cells over time. These findings underscore the influence of immune composition and daratumumab-induced immune changes in promoting MM resistance. Integrating genomics and flow cytometry unveiled associations between adverse genomic features and immune patterns. Overall, this study sheds light on the intricate interplay between genomic complexity and the immune microenvironment driving resistance to Dara-Rd in patients with RRMM.
Subject(s)
Antibodies, Monoclonal , Drug Resistance, Neoplasm , Multiple Myeloma , Humans , Multiple Myeloma/drug therapy , Multiple Myeloma/genetics , Multiple Myeloma/immunology , Antibodies, Monoclonal/therapeutic use , Female , Male , Dexamethasone/therapeutic use , Dexamethasone/pharmacology , Aged , Middle Aged , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Lenalidomide/therapeutic use , Lenalidomide/pharmacology , Genomics/methodsABSTRACT
Multiple myeloma (MM) is a heterogeneous disease characterized by frequent MYC translocations. Sporadic MYC activation in the germinal center of genetically engineered Vk*MYC mice is sufficient to induce plasma cell tumors in which a variety of secondary mutations are spontaneously acquired and selected over time. Analysis of 119 Vk*MYC myeloma reveals recurrent copy number alterations, structural variations, chromothripsis, driver mutations, apolipoprotein B mRNA-editing enzyme, catalytic polypeptide (APOBEC) mutational activity, and a progressive decrease in immunoglobulin transcription that inversely correlates with proliferation. Moreover, we identify frequent insertional mutagenesis by endogenous retro-elements as a murine specific mechanism to activate NF-kB and IL6 signaling pathways shared with human MM. Despite the increased genomic complexity associated with progression, advanced tumors remain dependent on MYC. In summary, here we credential the Vk*MYC mouse as a unique resource to explore MM genomic evolution and describe a fully annotated collection of diverse and immortalized murine MM tumors.
Subject(s)
Multiple Myeloma , Proto-Oncogene Proteins c-myc , Animals , Multiple Myeloma/genetics , Multiple Myeloma/pathology , Humans , Mice , Proto-Oncogene Proteins c-myc/genetics , Proto-Oncogene Proteins c-myc/metabolism , Cell Transformation, Neoplastic/genetics , Mutation , Signal Transduction/genetics , Mice, Transgenic , NF-kappa B/metabolism , NF-kappa B/genetics , Mutagenesis, Insertional , DNA Copy Number Variations/genetics , Genomics/methods , Translocation, GeneticABSTRACT
To comprehensively unravel the temporal relationship between initiating and driver events and its impact on clinical outcomes, we analyzed 421 whole-genome sequencing profiles from 382 patients. Using clock-like mutational signatures, we estimated a time lag of 2-4 decades between initiating events and diagnosis. In patients with hyperdiploidy, we demonstrate that trisomies of odd-numbered chromosomes can be acquired simultaneously with other chromosomal gains, such as 1q gain. We provide evidence that hyperdiploidy is acquired after canonical IGH translocation when both events are present. Finally, patients with early 1q gain had adverse outcomes similar to those with 1q amplification (>1 extra-copies), but faring worse than those with late 1q gain. This underscores that the prognostic impact of 1q gain/amp depends more on the timing of acquisition than on the number of extra copies gained. Overall, this study contributes to a better understanding of the life history of MM and may have prognostic implications.
ABSTRACT
PURPOSE: Outcomes for patients with newly diagnosed multiple myeloma (NDMM) are heterogenous, with overall survival (OS) ranging from months to over 10 years. METHODS: To decipher and predict the molecular and clinical heterogeneity of NDMM, we assembled a series of 1,933 patients with available clinical, genomic, and therapeutic data. RESULTS: Leveraging a comprehensive catalog of genomic drivers, we identified 12 groups, expanding on previous gene expression-based molecular classifications. To build a model predicting individualized risk in NDMM (IRMMa), we integrated clinical, genomic, and treatment variables. To correct for time-dependent variables, including high-dose melphalan followed by autologous stem-cell transplantation (HDM-ASCT), and maintenance therapy, a multi-state model was designed. The IRMMa model accuracy was significantly higher than all comparator prognostic models, with a c-index for OS of 0.726, compared with International Staging System (ISS; 0.61), revised-ISS (0.572), and R2-ISS (0.625). Integral to model accuracy was 20 genomic features, including 1q21 gain/amp, del 1p, TP53 loss, NSD2 translocations, APOBEC mutational signatures, and copy-number signatures (reflecting the complex structural variant chromothripsis). IRMMa accuracy and superiority compared with other prognostic models were validated on 256 patients enrolled in the GMMG-HD6 (ClinicalTrials.gov identifier: NCT02495922) clinical trial. Individualized patient risks were significantly affected across the 12 genomic groups by different treatment strategies (ie, treatment variance), which was used to identify patients for whom HDM-ASCT is particularly effective versus patients for whom the impact is limited. CONCLUSION: Integrating clinical, demographic, genomic, and therapeutic data, to our knowledge, we have developed the first individualized risk-prediction model enabling personally tailored therapeutic decisions for patients with NDMM.
Subject(s)
Hematopoietic Stem Cell Transplantation , Multiple Myeloma , Humans , Multiple Myeloma/genetics , Multiple Myeloma/therapy , Multiple Myeloma/diagnosis , Prognosis , Melphalan , Hematopoietic Stem Cell Transplantation/adverse effects , Genomics , Transplantation, Autologous , Retrospective StudiesABSTRACT
Whole genome sequencing (WGS) of newly diagnosed multiple myeloma patients (NDMM) has shown recurrent structural variant (SV) involvement in distinct regions of the genome (i.e. hotspots) and causing recurrent copy number alterations. Together with canonical immunoglobulin translocations, these SVs are recognized as "recurrent SVs". More than half SVs were not involved in recurrent events. The significance of these "rare SVs" has not been previously examined. In this study, we utilize 752 WGS and 591 RNA-seq data from NDMM patients to determine the role of rare SVs in myeloma pathogenesis. 94% of patients harbored at least one rare SV event. Rare SVs showed an SV-class specific enrichment within genes and superenhancers associated with outlier gene expression. Furthermore, known myeloma driver genes recurrently impacted by point mutations were dysregulated by rare SVs. Overall, we demonstrate the association of rare SVs with aberrant gene expression supporting a driver role in myeloma pathogenesis. SIGNIFICANCE: Characterization of multiple myeloma genome revealed that more than half structural variants are not involved in recurrent events. Here, we demonstrate that these rare SVs hold potential for myeloma pathogenesis through their gene expression impact. Rare SVs contribute to MM heterogeneity and have implications for development of individualized treatment.
ABSTRACT
Anti-CD38 antibody therapies have transformed multiple myeloma (MM) treatment. However, a large fraction of patients inevitably relapses. To understand this, we investigated 32 relapsed MM patients treated with daratumumab, lenalidomide, and dexamethasone (Dara-Rd; NCT03848676 ). Whole genome sequencing (WGS) before and after treatment pinpointed genomic drivers associated with early progression, including RPL5 loss and APOBEC mutagenesis. Flow cytometry on 202 blood samples, collected every three months until progression for 31 patients, revealed distinct immune changes significantly impacting clinical outcomes. Progressing patients exhibited significant depletion of CD38+ NK cells, persistence of T cell exhaustion, and reduced depletion of T-reg cells over time. These findings underscore the influence of immune composition and daratumumab-induced immune changes in promoting MM resistance. Integrating genomics and flow cytometry unveiled associations between adverse genomic features and immune patterns. Overall, this study sheds light on the intricate interplay between genomic complexity and the immune microenvironment driving resistance to Dara-Rd.
ABSTRACT
Despite advancements in profiling multiple myeloma (MM) and its precursor conditions, there is limited information on mechanisms underlying disease progression. Clincal efforts designed to deconvolute such mechanisms are challenged by the long lead time between monoclonal gammopathy and its transformation to MM. MM mouse models represent an opportunity to overcome this temporal limitation. Here, we profile the genomic landscape of 118 genetically engineered Vk*MYC MM and reveal that it recapitulates the genomic heterogenenity and life history of human MM. We observed recurrent copy number alterations, structural variations, chromothripsis, driver mutations, APOBEC mutational activity, and a progressive decrease in immunoglobulin transcription that inversely correlates with proliferation. Moreover, we identified frequent insertional mutagenesis by endogenous retro-elements as a murine specific mechanism to activate NF-kB and IL6 signaling pathways shared with human MM. Despite the increased genomic complexity associated with progression, advanced tumors remain dependent on MYC expression, that drives the progression of monoclonal gammopathy to MM.
ABSTRACT
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.
Subject(s)
Lymphoma, B-Cell , Waldenstrom Macroglobulinemia , Humans , Waldenstrom Macroglobulinemia/genetics , DNA Copy Number Variations , Myeloid Differentiation Factor 88/genetics , Mutation , Lymphoma, B-Cell/genetics , Germinal CenterABSTRACT
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.
Subject(s)
Hodgkin Disease , Reed-Sternberg Cells , Humans , Reed-Sternberg Cells/pathology , Hodgkin Disease/genetics , Hodgkin Disease/pathology , Flow Cytometry , Evolution, MolecularABSTRACT
B cell maturation antigen (BCMA) target loss is considered to be a rare event that mediates multiple myeloma (MM) resistance to anti-BCMA chimeric antigen receptor T cell (CAR T) or bispecific T cell engager (TCE) therapies. Emerging data report that downregulation of G-protein-coupled receptor family C group 5 member D (GPRC5D) protein often occurs at relapse after anti-GPRC5D CAR T therapy. To examine the tumor-intrinsic factors that promote MM antigen escape, we performed combined bulk and single-cell whole-genome sequencing and copy number variation analysis of 30 patients treated with anti-BCMA and/or anti-GPRC5D CAR T/TCE therapy. In two cases, MM relapse post-TCE/CAR T therapy was driven by BCMA-negative clones harboring focal biallelic deletions at the TNFRSF17 locus at relapse or by selective expansion of pre-existing subclones with biallelic TNFRSF17 loss. In another five cases of relapse, newly detected, nontruncating, missense mutations or in-frame deletions in the extracellular domain of BCMA negated the efficacies of anti-BCMA TCE therapies, despite detectable surface BCMA protein expression. In the present study, we also report four cases of MM relapse with biallelic mutations of GPRC5D after anti-GPRC5D TCE therapy, including two cases with convergent evolution where multiple subclones lost GPRC5D through somatic events. Immunoselection of BCMA- or GPRC5D-negative or mutant clones is an important tumor-intrinsic driver of relapse post-targeted therapies. Mutational events on BCMA confer distinct sensitivities toward different anti-BCMA therapies, underscoring the importance of considering the tumor antigen landscape for optimal design and selection of targeted immunotherapies in MM.
Subject(s)
Multiple Myeloma , Receptors, Chimeric Antigen , Humans , Multiple Myeloma/genetics , Multiple Myeloma/therapy , Antigenic Drift and Shift , DNA Copy Number Variations , Neoplasm Recurrence, Local , Immunotherapy , Antibodies , Membrane ProteinsABSTRACT
Despite improving outcomes, 40% of patients with newly diagnosed multiple myeloma treated with regimens containing daratumumab, a CD38-targeted monoclonal antibody, progress prematurely. By integrating tumor whole-genome and microenvironment single-cell RNA sequencing from upfront phase 2 trials using carfilzomib, lenalidomide and dexamethasone with daratumumab ( NCT03290950 ), we show how distinct genomic drivers including high APOBEC mutational activity, IKZF3 and RPL5 deletions and 8q gain affect clinical outcomes. Furthermore, evaluation of paired bone marrow profiles, taken before and after eight cycles of carfilzomib, lenalidomide and dexamethasone with daratumumab, shows that numbers of natural killer cells before treatment, high T cell receptor diversity before treatment, the disappearance of sustained immune activation (that is, B cells and T cells) and monocyte expansion over time are all predictive of sustained minimal residual disease negativity. Overall, this study provides strong evidence of a complex interplay between tumor cells and the immune microenvironment that is predictive of clinical outcome and depth of treatment response in patients with newly diagnosed multiple myeloma treated with highly effective combinations containing anti-CD38 antibodies.