Role of minimal residual disease assessment in multiple myeloma.

Multiple myeloma (MM) is a hematologic malignancy characterized by clonal proliferation of plasma cells. MM is a heterogeneous disease, featured by various molecular subtypes with different outcomes. With the advent of very efficient therapies including monoclonal antibodies, bispecific T cell engagers and chimeric antigen receptor T cells (CAR T cells), most of MM patients have now a prolonged survival. However, the disease remains incurable, and a subgroup of high-risk patients continue to have early relapse and short survival. Novel and highly sensitive methods have been developed allowing to detect minimal residual disease (MRD) during or after treatment. Achievement of MRD negativity is a strong and independent prognosis factor in both prospective randomized clinical trials and in real-world setting. While MRD assessment is now a validated endpoint in clinical trials, its incorporation in clinical practice is not yet established and its potential impact on guiding therapy remains under deep evaluation. We discuss in this chapter, the different available methods allowing MRD assessment and the role of MRD evaluation in multiple myeloma management.

Body size and risk of multiple myeloma in the Black Women's Health Study.

BACKGROUND: Obesity is an established risk factor for multiple myeloma (MM). Relatively few prior studies, however, have evaluated associations in Black populations. METHODS: Among 55,276 participants in the Black Women's Health Study, a prospective U.S. cohort established in 1995, we confirmed 292 incident diagnoses of MM over 26 years of follow-up. Multivariable Cox proportional hazard models, adjusted for age and putative MM risk factors, were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for associations of usual body mass index (BMI), BMI at age 18, height, and waist-to-hip ratio with MM. RESULTS: Compared to women with a usual adult BMI < 25 kg/m2, the HR associated with a usual adult BMI ≥ 35 kg/m2 was 1.38 (95% CI: 0.96, 1.98). For early adult BMI, the HR comparing women with BMI ≥ 25 vs. <25 kg/m2 was 1.57 (95% CI: 1.08, 2.28). Women who were heavy in both early and later life had the highest risk compared to those who were lean at both time points (HR: 1.60; 95% CI: 1.02, 2.52). Height was also associated with the risk of MM; the HR per 10 cm was 1.21 (95% CI: 1.02, 1.43). CONCLUSIONS: These results indicate that high early adult BMI is associated with a 57% increased risk of MM in Black women and potentially highlight the importance of weight control as a preventive measure.

Single-cell profiling in multiple myeloma: insights, problems, and promises.

In a short time, single-cell platforms have become the norm in many fields of research, including multiple myeloma (MM). In fact, the large amount of cellular heterogeneity in MM makes single-cell platforms particularly attractive because bulk assessments can miss valuable information about cellular subpopulations and cell-to-cell interactions. The decreasing cost and increasing accessibility of single-cell platform, combined with breakthroughs in obtaining multiomics data for the same cell and innovative computational programs for analyzing data, have allowed single-cell studies to make important insights into MM pathogenesis; yet, there is still much to be done. In this review, we will first focus on the types of single-cell profiling and the considerations for designing a single-cell profiling experiment. Then, we will discuss what have learned from single-cell profiling about myeloma clonal evolution, transcriptional reprogramming, and drug resistance, and about the MM microenvironment during precursor and advanced disease.

High-dose melphalan treatment significantly increases mutational burden at relapse in multiple myeloma.

High-dose melphalan (HDM) improves progression-free survival in multiple myeloma (MM), yet melphalan is a DNA-damaging alkylating agent; therefore, we assessed its mutational effect on surviving myeloma cells by analyzing paired MM samples collected at diagnosis and relapse in the IFM 2009 study. We performed deep whole-genome sequencing on samples from 68 patients, 43 of whom were treated with RVD (lenalidomide, bortezomib, and dexamethasone) and 25 with RVD + HDM. Although the number of mutations was similar at diagnosis in both groups (7137 vs 7230; P = .67), the HDM group had significantly more mutations at relapse (9242 vs 13 383, P = .005). No change in the frequency of copy number alterations or structural variants was observed. The newly acquired mutations were typically associated with DNA damage and double-stranded breaks and were predominantly on the transcribed strand. A machine learning model, using this unique pattern, predicted patients who would receive HDM with high sensitivity, specificity, and positive prediction value. Clonal evolution analysis showed that all patients treated with HDM had clonal selection, whereas a static progression was observed with RVD. A significantly higher percentage of mutations were subclonal in the HDM cohort. Intriguingly, patients treated with HDM who achieved complete remission (CR) had significantly more mutations at relapse yet had similar survival rates as those treated with RVD who achieved CR. This similarity could have been due to HDM relapse samples having significantly more neoantigens. Overall, our study identifies increased genomic changes associated with HDM and provides rationale to further understand clonal complexity.

Graded Cardiac Response Criteria for Patients With Systemic Light Chain Amyloidosis.

PURPOSE: Binary cardiac response assessment using cardiac biomarkers is prognostic in light chain amyloidosis. Previous studies suggested four-level cardiac responses using N-terminal prohormone of brain natiuretic peptide improves prognostic prediction. This study was designed to validate graded cardiac response criteria using N-terminal prohormone of brain natiuretic peptide/brain natiuretic peptide. PATIENTS AND METHODS: This retrospective, multicenter study included patients with light chain amyloidosis who achieved at least a hematologic partial response (PR) and were evaluable for cardiac response. Four response criteria were tested on the basis of natriuretic peptide response depth: cardiac complete response (CarCR), cardiac very good partial response (CarVGPR), cardiac PR (CarPR), and cardiac no response (CarNR). Response was classified as best response and at fixed time points (6, 12, and 24 months from therapy initiation). The study primary outcome was overall survival. RESULTS: 651 patients were included. Best CarCR, CarVGPR, CarPR, and CarNR were achieved in 16%, 26.4%, 22.9%, and 34.7% of patients, respectively. Patients in cardiac stage II were more likely to achieve CarCR than patients in cardiac stage IIIA and IIIB (22% v 13.5% v 3.2%; P < .001). A deeper cardiac response was associated with a longer survival (5-year overall survival 93%, 79%, 65%, and 33% for CarCR, CarVGPR, CarPR, and CarNR, respectively; P < .001). Fixed time-point analyses and time-varying covariates Cox regression analysis, to minimize survivorship bias, affirmed the independent survival advantage of deeper cardiac responses. Four-level response performed better than two-level response as early as 12 months from therapy initiation. CONCLUSION: Graded cardiac response criteria allow better assessment of cardiac improvement compared with the traditional binary response system. The study re-emphasizes the importance of early diagnosis, which increases the likelihood of deep cardiac responses.

Predictors of hematologic response and survival with stem cell transplantation in AL amyloidosis: A 25-year longitudinal study.

High-dose melphalan and stem cell transplantation (HDM/SCT) is an effective treatment for selected patients with AL amyloidosis. We report the long-term outcomes of 648 patients with AL amyloidosis treated with HDM/SCT over 25 years. Hematologic CR was achieved by 39% of patients. The median duration of hematologic CR was 12.3 years, and 45% of patients with a hematologic CR had no evidence of a recurrent plasma cell dyscrasia at 15 years after HDM/SCT. With a median follow-up interval of 8 years, the median event-free survival (EFS) and overall survival (OS) were 3.3 and 7.6 years, respectively. Patients with a hematologic CR had a median OS of 15 years, and 30% of these patients survived >20 years. On multivariable analysis, dFLC >180 mg/L and BM plasma cells >10% were independently associated with shorter EFS, whereas BNP >81 pg/mL, troponin I > 0.1 ng/mL, and serum creatinine >2.0 mg/dL were independently associated with shorter OS. We developed a prognostic score for EFS, which incorporated dFLC >180 mg/L and BMPC% >10% as adverse risk factors. Patients with low-risk (0 factors), intermediate-risk (1 factor), and high-risk (2 factors) disease had median EFS estimates of 5.3, 2.8, and 1.0 years, respectively (p < .001). The 100-day treatment-related mortality rate was 3% in the latest treatment period (2012-2021), and the 25-year risk of t-MDS/AML was 3%. We conclude that HDM/SCT induces durable hematologic responses and prolonged survival with improved safety in selected patients with AL amyloidosis.

Predictive factors of outcomes in patients with AL amyloidosis treated with daratumumab.

Daratumumab as a single agent (sDARA) or in combination with chemotherapies (cDARA) leads to impressive hematologic and organ responses in AL amyloidosis. However, predictive factors associated with outcomes, and optimal duration of therapy remain unclear. We analyzed 107 patients with AL amyloidosis treated with daratumumab between 2017 and 2020. The median overall survival (OS) was not reached while the median major organ deterioration progression free survival (MOD-PFS) was 36 months in the sDARA cohort and not reached in the cDARA cohort, respectively. Hematologic response > VGPR was achieved in 81% of patients receiving sDARA and 86% of patients treated with cDARA. Several predictive factors were identified on a univariate analysis, including NTproBNP >8500 pg/mL but only achievement of at least VGPR and presence of 1q21 gain were independently associated with MOD-PFS and OS on a multivariate analysis. Finally, patients receiving > 12 cycles had significantly longer MOD-PFS (30 vs.13 months; (p = .0018) and OS (NR vs. 15 months; p < .0001). NTproBNP > 8500 pg/mL, presence of 1q21 gain and shorter duration of therapy (≤ 12 cycles) are strong negative predictive factors for outcomes with daratumumab therapy in AL amyloidosis.

IgM-MM is predominantly a pre-germinal center disorder and has a distinct genomic and transcriptomic signature from WM.

Immunoglobulin M (IgM) multiple myeloma (MM) is a rare disease subgroup. Its differentiation from other IgM-producing gammopathies such as Waldenström macroglobulinemia (WM) has not been well characterized but is essential for proper risk assessment and treatment. In this study, we investigated genomic and transcriptomic characteristics of IgM-MM samples using whole-genome and transcriptome sequencing to identify differentiating characteristics from non-IgM-MM and WM. Our results suggest that IgM-MM shares most of its defining structural variants and gene-expression profiling with MM, but has some key characteristics, including t(11;14) translocation, chromosome 6 and 13 deletion as well as distinct molecular and transcription-factor signatures. Furthermore, IgM-MM translocations were predominantly characterized by VHDHJH recombination-induced breakpoints, as opposed to the usual class-switching region breakpoints; coupled with its lack of class switching, these data favor a pre-germinal center origin. Finally, we found elevated expression of clinically relevant targets, including CD20 and Bruton tyrosine kinase, as well as high BCL2/BCL2L1 ratio in IgM-MM, providing potential for targeted therapeutics.

Lack of differential impact of del17p on survival in African Americans compared with White patients with multiple myeloma: a VA study.

Multiple myeloma (MM) is a heterogeneous disease that has an increased incidence in African Americans (AAs). We previously observed that, with equal access to health care, younger AA patients (age < 65 years) have superior overall survival (OS) compared with younger White patients. Because MM prognosis is influenced by 17p deletion (del17p), we investigated racial differences in its occurrence and impact in a large cohort of MM patients from the Veterans Affairs (VA) system. Among 2243 VA patients with MM for whom del17p data were available, del17p was present in 8.83% of all patients, with a significantly lower prevalence in AAs (5.56%) compared with Whites (10.52%; P < .001). The difference was even more pronounced among younger AAs (<65 years) vs younger Whites (4.34% vs 9.8%, respectively; P = .004). However, we did not observe any significant difference in survival between AA and White patients with del17p, regardless of age category, suggesting that del17p carries a poor prognosis across race and age. Interestingly, among patients without del17p, we still noted a significantly superior OS in younger AAs compared with younger Whites (7.75 vs 5.10 years; P = .042). Our study shows a lower incidence of del17p in AAs but suggests that the survival advantage for younger AAs is primarily due to factors other than del17p.

Pathogenetic and Prognostic Implications of Increased Mitochondrial Content in Multiple Myeloma.

Many studies over the last 20 years have investigated the role of mitochondrial DNA (mtDNA) alterations in carcinogenesis. However, the status of the mtDNACN in MM and its implication in the pathogenesis of the disease remains unclear. We examined changes in plasma cell mtDNACN across different stages of MM by applying RT-PCR and high-throughput sequencing analysis. We observed a significant increase in the average mtDNACN in myeloma cells compared with healthy plasma cells (157 vs. 40 copies; p = 0.02). We also found an increase in mtDNACN in SMM and newly diagnosed MM (NDMM) paired samples and in consecutive relapses in the same patient. Survival analysis revealed the negative impact of a high mtDNACN in progression-free survival in NDMM (p = 0.005). Additionally, we confirmed the higher expression of mitochondrial biogenesis regulator genes in myeloma cells than in healthy plasma cells and we detected single nucleotide variants in several genes involved in mtDNA replication. Finally, we found that there was molecular similarity between "rapidly-progressing SMM" and MM regarding mtDNACN. Our data provide evidence that malignant transformation of myeloma cells involves the activation of mitochondrial biogenesis, resulting in increased mtDNA levels, and highlights vulnerabilities and potential therapeutic targets in the treatment of MM. Accordingly, mtDNACN tracking might guide clinical decision-making and management of complex entities such as high-risk SMM.

Genetic Predictors of Mortality in Patients with Multiple Myeloma.

Multiple myeloma (MM) is a heterogeneous disease featured by clonal plasma cell proliferation and genomic instability. The advent of next-generation sequencing allowed unraveling the complex genomic landscape of the disease. Several recurrent genomic aberrations including immunoglobulin genes translocations, copy number abnormalities, complex chromosomal events, transcriptomic and epigenomic deregulation, and mutations define various molecular subgroups with distinct outcomes. In this review, we describe the recurrent genomic events identified in MM impacting patients' outcome and survival. These genomic aberrations constitute new markers that could be incorporated into a prognostication model to eventually guide therapy at every stage of the disease.

Prevalence and Outcome of COVID-19 Infection in Cancer Patients: A National Veterans Affairs Study.

BACKGROUND: Emerging data suggest variability in susceptibility and outcome to coronavirus disease 2019 (COVID-19) infection. Identifying risk factors associated with infection and outcomes in cancer patients is necessary to develop healthcare recommendations. METHODS: We analyzed electronic health records of the US Veterans Affairs Healthcare System and assessed the prevalence of COVID-19 infection in cancer patients. We evaluated the proportion of cancer patients tested for COVID-19 who were positive, as well as outcome attributable to COVID-19, and stratified by clinical characteristics including demographics, comorbidities, cancer treatment, and cancer type. All statistical tests are 2-sided. RESULTS: Of 22 914 cancer patients tested for COVID-19, 1794 (7.8%) were positive. The prevalence of COVID-19 was similar across age. Higher prevalence was observed in African American (15.0%) compared with White (5.5%; P < .001) and in patients with hematologic malignancy compared with those with solid tumors (10.9% vs 7.8%; P < .001). Conversely, prevalence was lower in current smokers and patients who recently received cancer therapy (<6 months). The COVID-19-attributable mortality was 10.9%. Higher attributable mortality rates were observed in older patients, those with higher Charlson comorbidity score, and in certain cancer types. Recent (<6 months) or past treatment did not influence attributable mortality. Importantly, African American patients had 3.5-fold higher COVID-19-attributable hospitalization; however, they had similar attributable mortality as White patients. CONCLUSION: Preexistence of cancer affects both susceptibility to COVID-19 infection and eventual outcome. The overall COVID-19-attributable mortality in cancer patients is affected by age, comorbidity, and specific cancer types; however, race or recent treatment including immunotherapy do not impact outcome.

Genome-Wide Somatic Alterations in Multiple Myeloma Reveal a Superior Outcome Group.

PURPOSE: Multiple myeloma (MM) is accompanied by heterogeneous somatic alterations. The overall goal of this study was to describe the genomic landscape of myeloma using deep whole-genome sequencing (WGS) and develop a model that identifies patients with long survival. METHODS: We analyzed deep WGS data from 183 newly diagnosed patients with MM treated with lenalidomide, bortezomib, and dexamethasone (RVD) alone or RVD + autologous stem cell transplant (ASCT) in the IFM/DFCI 2009 study (ClinicalTrials.gov identifier: NCT01191060). We integrated genomic markers with clinical data. RESULTS: We report significant variability in mutational load and processes within MM subgroups. The timeline of observed activation of mutational processes provides the basis for 2 distinct models of acquisition of mutational changes detected at the time of diagnosis of myeloma. Virtually all MM subgroups have activated DNA repair-associated signature as a prominent late mutational process, whereas APOBEC signature targeting C>G is activated in the intermediate phase of disease progression in high-risk MM. Importantly, we identify a genomically defined MM subgroup (17% of newly diagnosed patients) with low DNA damage (low genomic scar score with chromosome 9 gain) and a superior outcome (100% overall survival at 69 months), which was validated in a large independent cohort. This subgroup allowed us to distinguish patients with low- and high-risk hyperdiploid MM and identify patients with prolongation of progression-free survival. Genomic characteristics of this subgroup included lower mutational load with significant contribution from age-related mutations as well as frequent NRAS mutation. Surprisingly, their overall survival was independent of International Staging System and minimal residual disease status. CONCLUSION: This is a comprehensive study identifying genomic markers of a good-risk group with prolonged survival. Identification of this patient subgroup will affect future therapeutic algorithms and research planning.

Genomic Instability in Multiple Myeloma.

Genomic instability (GIN), an increased tendency to acquire genomic alterations, is a cancer hallmark. However, its frequency, underlying causes, and disease relevance vary across different cancers. Multiple myeloma (MM), a plasma cell malignancy, evolves through premalignant phases characterized by genomic abnormalities. Next-generation sequencing (NGS) methods are deconstructing the genomic landscape of MM across the continuum of its development, inextricably linking malignant transformation and disease progression with increasing acquisition of genomic alterations, and illuminating the mechanisms that generate these alterations. Although GIN drives disease evolution, it also creates vulnerabilities such as dependencies on 'superfluous' repair mechanisms and the induction of tumor-specific antigens that can be targeted. We review the mechanisms of GIN in MM, the associated vulnerabilities, and therapeutic targeting strategies.