Clonal hematopoiesis is associated with adverse outcomes in multiple myeloma patients undergoing transplant

Liquid biopsy for renal cell carcinoma

Liquid biopsies offer a less invasive alternative to tissue biopsies for diagnosis, prognosis, and determining therapeutic potential in renal cell carcinoma (RCC). Unfortunately, clinical studies using liquid biopsy biomarkers in RCC are limited. Accordingly, we examine RCC biomarkers, derived from urine, plasma, serum and feces of potential impact and clinical outcome in these patients. A PRISMA checklist was used to identify valuable liquid biopsy biomarkers for diagnosis (plasma cfDNA, serum- or urine-derived circulating RNAs, exosomes and proteins), prognosis (plasma cfDNA, plasma- or serum-derived RNAs, and proteins), and therapeutic response (plasma- and serum-derived proteins). Although other analytes have been identified, their application for routine clinical use remains unclear. In general, panels appear more effective than single biomarkers. Important considerations included proof of reproducibility. Unfortunately, many of the examined studies were insufficiently large and lacked multi-center rigor. Cost-effectiveness was also not available. Accordingly, it is clear that more standardized protocols need to be developed before liquid biopsies can be successfully integrated into clinical practice in RCC.

Mosaic chromosomal alterations in hematopoietic cells and clinical outcomes in patients with multiple myeloma

Mosaic chromosomal alterations (mCAs) in hematopoietic cells increase mortality and risk of hematological cancers and infections. We investigated the landscape of mCAs and their clinical consequences in 976 patients with multiple myeloma undergoing high-dose chemotherapy and autologous stem cell support (ASCT) with median 6.4 years of follow-up. mCAs were detected in the stem cell harvest product of 158 patients (16.2%). Autosomal aberrations were found in 60 patients (6.1%) and affected all chromosomes. Loss of chromosome X was found in 51 females (12.7%) and loss of chromosome Y in 55 males (9.6%). Overall survival and progression were similar between carriers of autosomal mCAs and non-carriers. In contrast, female patients with loss of the X chromosome had longer overall survival (age-adjusted[a.a.] HR 0.54, 95% CI 0.32-0.93, p = 0.02), lower risk of progression (a.a. HR 0.55, 95% CI 0.35-0.87; p = 0.01), and better post-transplant response (higher degree of complete response (CR) or very good partial response (VGPR)). The reason for this substantial effect is unknown. Additionally, myeloma clones in the stem cell product was confirmed by mCA analysis in the few patients with multiple mCAs (n = 12 patients). Multiple mCAs conferred inferior overall survival (a.a. HR 2.0, 95% CI 1.02-3.84; p = 0.04) and higher risk of myeloma progression (a.a. HR 3.36, 95% CI 1.67-6.81; p < 0.001), which is presumed to be driven by suspected myeloma contaminants.

The role of clonal progression leading to the development of therapy-related myeloid neoplasms

Therapy-related myeloid neoplasms (t-MN) are characterized by aggressive features and a dismal prognosis. Recent evidence suggests a higher incidence of t-MN in individuals harboring clonal hematopoiesis of indeterminate potential (CHIP). In order to gain insight into CHIP-driven malignant progression, we gathered data from ten published reports with available detailed patient characteristics at the time of primary malignancy and t-MN development. Detailed clinical and molecular information on primary malignancy and t-MN were available for 109 patients: 43% harbored at least one somatic mutation at the time of the primary malignancy. TET2 and TP53 mutations showed an increasing variant allele frequency from CHIP to t-MN. ASXL1-associated CHIP significantly correlated with the emergence of TET2 and CEBPA mutations at t-MN, as well as U2AF1-driven CHIP with EZH2 mutation and both IDH2 and SRSF2-driven CHIP with FLT3 mutation. DNMT3A-driven CHIP correlated with a lower incidence of TP53 mutation at t-MN. In contrast, TP53-driven CHIP correlated with a complex karyotype and a lower tendency to acquire new mutations at t-MN. Patients with multiple myeloma as their first malignancy presented a significantly higher rate of TP53 mutations at t-MN. The progression from CHIP to t-MN shows different scenarios depending on the genes involved. A deeper knowledge of CHIP progression mechanisms will allow a more reliable definition of t-MN risk.

Effects of donor-engrafted clonal hematopoiesis in allogeneic and autologous stem cell transplantation: a systematic review and meta-analysis

Donor stem cell health may be critically important to the success of hematopoietic stem cell transplantation (HSCT). Herein, we performed this systematic review and meta-analysis including meta-regression to assess the impact of donor-engrafted clonal hematopoiesis (CH) in allogeneic HSCT (allo-HSCT) and impact of pre-transplant CH in autologous HSCT (auto-HSCT). We applied random-effects models to analyze 5 allo-HSCT studies with 3192 donor-recipient pairs and 9 auto-HSCT studies with 2854 patients. We found that donor-engrafted CH after allo-HSCT decreased the risk of disease relapse [Hazard Ratio (HR) = 0.79, 95% Confidence Interval (CI): (0.67, 0.93)], but did not affect overall survival (OS) [HR = 0.91, 95% CI: (0.75, 1.11)], progression-free survival (PFS) [HR = 0.94, 95% CI: (0.63, 1.41)], or non-relapse mortality [HR = 1.06, 95% CI: (0.81, 1.39)]. In contrast, pre-transplant CH in auto-HSCT recipients resulted in inferior OS [HR = 1.30, 95% CI: (1.16, 1.46)], inferior PFS [HR = 1.35, 95% CI: (1.18, 1.54)], and higher risk for therapy-related myeloid neoplasm [HR = 4.85, 95% CI: (2.39, 9.82)] when compared to auto-HSCT recipients without CH. This study sheds light onto the debate about prospective "CHIP screening" for stem cell donors and addresses the impact of CH as a transmissible phenomenon.

Senescence in the bone marrow microenvironment: A driver in development of therapy-related myeloid neoplasms

Therapy-related myeloid neoplasms (t-MN) are a growing concern due to the continued use of cytotoxic therapies to treat malignancies. Cytotoxic therapies have been shown to drive therapy-induced senescence in normal tissues, including in the bone marrow microenvironment (BMME), which plays a crucial role in supporting normal hematopoiesis. This review examines recent work that focuses on the contribution of BMME senescence to t-MN pathogenesis, as well as offers a perspective on potential opportunities for therapeutic intervention.

Cardiovascular Disease After Hematopoietic Stem Cell Transplantation in Adults: JACC: CardioOncology State-of-the-Art Review

The use of hematopoietic cell transplantation (HCT) has expanded in the last 4 decades to include an older and more comorbid population. These patients face an increased risk of cardiovascular disease after HCT. The risk varies depending on several factors, including the type of transplant (autologous or allogeneic). Many therapies used in HCT have the potential to be cardiotoxic. Cardiovascular complications after HCT include atrial arrhythmias, heart failure, myocardial infarction, and pericardial effusions. Before HCT, patients should undergo a comprehensive cardiovascular assessment, with ongoing surveillance tailored to their individual level of cardiovascular risk. In this review, we provide an overview of cardiotoxicity after HCT and outline our approach to risk assessment and ongoing care.

Rising Prevalence of Low-Frequency PPM1D Gene Mutations after Second HDCT in Multiple Myeloma

Multiple myeloma (MM) first-line treatment algorithms include immuno-chemotherapy (ICT) induction, high-dose chemotherapy (HDCT) and autologous stem cell transplant (ASCT) consolidation, followed by lenalidomide maintenance. After these initial therapies, most patients suffer a disease relapse and require subsequent treatment lines including ICT, additional HDCT and ASCT, or novel immunotherapies. The presence of somatic mutations in peripheral blood cells has been associated with adverse outcomes in a variety of hematological malignancies. Nonsense and frameshift mutations in the PPM1D gene, a frequent driver alteration in clonal hematopoiesis (CH), lead to the gain-of-function of Wip1 phosphatase, which may impair the p53-dependent G1 checkpoint and promote cell proliferation. Here, we determined the presence of PPM1D gene mutations in peripheral blood cells of 75 subsequent myeloma patients in remission after first or second HDCT/ASCT. The prevalence of truncating PPM1D gene mutations emerged at 1.3% after first HDCT/ASCT, and 7.3% after second HDCT/ASCT, with variant allele frequencies (VAF) of 0.01 to 0.05. Clinical outcomes were inferior in the PPM1D-mutated (PPM1Dmut) subset with median progression-free survival (PFS) of 15 vs. 37 months (p = 0.0002) and median overall survival (OS) of 36 vs. 156 months (p = 0.001) for the PPM1Dmut and PPM1Dwt population, respectively. Our data suggest that the occurrence of PPM1D gene mutations in peripheral blood cells correlates with inferior outcomes after ASCT in patients with multiple myeloma.

Clonal hematopoiesis of indeterminate potential in patients with immunoglobulin light-chain AL amyloidosis

ABSTRACT

Immunoglobulin light-chain (AL) amyloidosis is characterized by the deposition of misfolded monoclonal free light chains, with cardiac complications accounting for patient mortality. Clonal hematopoiesis of indeterminate potential (CHIP) has been associated with worse cardiovascular outcomes in the general population. Its significance in AL amyloidosis remains unclear. We collected clinical information and outcome data on 76 patients with a diagnosis of AL amyloidosis who underwent deep targeted sequencing for myeloid neoplasia-associated mutations between April 2018 and August 2023. Variant allele frequency was set at 2% to call CHIP-associated mutations. CHIP mutations were present in patients with AL amyloidosis at a higher frequency compared with age-matched control individuals. Sixteen patients (21%) had at least 1 CHIP mutation. DNMT3A was the most frequent mutation (7/16; 44%). Compared with patients without CHIP, patients with CHIP had a higher prevalence of t(11;14) translocation (69% vs 25%, respectively; P = .004). Furthermore, among patients with renal involvement, those with CHIP had a lower Palladini renal stage (P = .001). At a median follow-up of 32.5 months, the presence of CHIP was not associated with worse overall survival or major organ dysfunction progression-free survival. Larger studies and longer follow-up are needed to better define the impact of CHIP in patients with AL amyloidosis.

The impact of cytotoxic therapy on the risk of progression and death in clonal cytopenia(s) of undetermined significance

ABSTRACT

Clonal cytopenia of undetermined significance (CCUS) is defined by a myeloid driver mutation in the context of otherwise unexplained cytopenia. CCUS has an inherent risk of progressing to myeloid neoplasm. However, it is unknown how exposure to previous cytotoxic therapy may impact the risk of progression and survival. We stratified patients with CCUS by prior exposure to DNA-damaging therapy. Of 151 patients, 46 (30%) had received cytotoxic therapy and were classified as therapy-related CCUS (t-CCUS), whereas 105 (70%) had de novo CCUS. A lower proportion of t-CCUS had hypercellular marrows (17.8% vs 44.8%, P = .002) but had higher median bone marrow blast percentages. After a median follow-up of 2.2 years, t-CCUS had significantly shorter progression-free survival (PFS, 1.8 vs 6.3 years; hazard ratio [HR], 2.1; P = .007) and median overall survival (OS; 3.6 years vs not reached; HR, 2.3; P = .007) compared with CCUS. Univariable and multivariable time-to-event analyses showed that exposure to cytotoxic therapy independently accounted for inferior PFS and OS. Despite the similarities in clinical presentation between CCUS and t-CCUS, we show that exposure to prior cytotoxic therapies was an independent risk factor for inferior outcomes. This suggests that t-CCUS represents a unique clinical entity that needs more stringent monitoring or earlier intervention strategies.

Clonal hematopoiesis of indeterminate potential is rare in pediatric patients undergoing autologous stem cell transplantation

Clonal hematopoiesis of indeterminate potential (CHIP) describes recurrent somatic gene mutations in the blood of healthy individuals, associated with higher risk for hematological malignancies and higher all-cause mortality by cardiovascular disease. CHIP increases with age and is more common in adult patients after chemotherapy or radiation for cancer. Furthermore, in some adult patients undergoing autologous stem cell transplantation (ASCT) or thereafter, CHIP has been identified. In children and adolescents, it remains unclear how cellular stressors such as cytotoxic therapy influence the incidence and expansion of CHIP. We conducted a retrospective study on 33 pediatric patients mostly with solid tumors undergoing ASCT for presence of CHIP. We analyzed CD34+ selected peripheral blood stem cell grafts after several cycles of chemotherapy, prior to cell infusion, by next-generation sequencing including 18 "CHIP-genes". Apart from a somatic variant in TP53 in one patient no other variants indicative of CHIP were identified. As a CHIP-unrelated finding, germline variants in CHEK2 and in ATM were identified in two and four patients, respectively. In conclusion, we could not detect "typical" CHIP variants in our cohort of pediatric cancer patients undergoing ASCT. However, more studies with larger patient numbers are necessary to assess if chemotherapy in the pediatric setting contributes to an increased CHIP incidence and at what time point.

ctDNA improves prognostic prediction for patients with relapsed/refractory MM receiving ixazomib, lenalidomide, and dexamethasone

ABSTRACT

It remains elusive how driver mutations, including those detected in circulating tumor DNA (ctDNA), affect prognosis in relapsed/refractory multiple myeloma (RRMM). Here, we performed targeted-capture sequencing using bone marrow plasma cells (BMPCs) and ctDNA of 261 RRMM cases uniformly treated with ixazomib, lenalidomide, and dexamethasone in a multicenter, prospective, observational study. We detected 24 and 47 recurrently mutated genes in BMPC and ctDNA, respectively. In addition to clonal hematopoiesis-associated mutations, varying proportion of driver mutations, particularly TP53 mutations (59.2% of mutated cases), were present in only ctDNA, suggesting their subclonal origin. In univariable analyses, ctDNA mutations of KRAS, TP53, DIS3, BRAF, NRAS, and ATM were associated with worse progression-free survival (PFS). BMPC mutations of TP53 and KRAS were associated with inferior PFS, whereas KRAS mutations were prognostically relevant only when detected in both BMPC and ctDNA. A total number of ctDNA mutations in the 6 relevant genes was a strong prognostic predictor (2-year PFS rates: 57.3%, 22.7%, and 0% for 0, 1, and ≥2 mutations, respectively) and independent of clinical factors and plasma DNA concentration. Using the number of ctDNA mutations, plasma DNA concentration, and clinical factors, we developed a prognostic index, classifying patients into 3 categories with 2-year PFS rates of 57.9%, 28.6%, and 0%. Serial analysis of ctDNA mutations in 94 cases revealed that TP53 and KRAS mutations frequently emerge after therapy. Thus, we clarify the genetic characteristics and clonal architecture of ctDNA mutations and demonstrate their superiority over BMPC mutations for prognostic prediction in RRMM. This study is a part of the C16042 study, which is registered at www.clinicaltrials.gov as #NCT03433001.

Sensitivity, specificity, and accuracy of molecular profiling on circulating cell-free DNA in refractory or relapsed multiple myeloma patients, results of MM-EP1 study

As a promising alternative to bone marrow aspiration (BMA), mutational profiling on blood-derived circulating cell-free tumor DNA (cfDNA) is a harmless and simple technique to monitor molecular response and treatment resistance of patients with refractory/relapsed multiple myeloma (R/R MM). We evaluated the sensitivity and specificity of cfDNA compared to BMA CD138 positive myeloma plasma cells (PCs) in a series of 45 R/R MM patients using the 29-gene targeted panel (AmpliSeq) NGS. KRAS, NRAS, FAM46C, DIS3, and TP53 were the most frequently mutated genes. The average sensitivity and specificity of cfDNA detection were 65% and 97%, respectively. The concordance per gene between the two samples was good to excellent according to Cohen's κ coefficients interpretation. An increased number of mutations detected in cfDNA were associated with a decreased overall survival. In conclusion, we demonstrated cfDNA NGS analysis feasibility and accuracy in R/R MM patients who may benefit from early phase clinical trial.

Clonal hematopoiesis-derived therapy-related myeloid neoplasms after autologous hematopoietic stem cell transplant for lymphoid and non-lymphoid disorders

Therapy-related myeloid neoplasms (tMN) are complications of cytotoxic therapies. Risk of tMN is high in recipients of autologous hematopoietic stem cell transplantation (aHSCT). Acquisition of genomic mutations represents a key pathogenic driver but the origins, timing and dynamics, particularly in the context of preexisting or emergent clonal hematopoiesis (CH), have not been sufficiently clarified. We studied a cohort of 1507 patients undergoing aHSCT and a cohort of 263 patients who developed tMN without aHSCT to determine clinico-molecular features unique to post-aHSCT tMN. We show that tMN occurs in up to 2.3% of patients at median of 2.6 years post-AHSCT. Age ≥ 60 years, male sex, radiotherapy, high treatment burden ( ≥ 3 lines of chemotherapy), and graft cellularity increased the risk of tMN. Time to evolution and overall survival were shorter in post-aHSCT tMN vs. other tMN, and the earlier group's mutational pattern was enriched in PPM1D and TP53 lesions. Preexisting CH increased the risk of adverse outcomes including post-aHSCT tMN. Particularly, antecedent lesions affecting PPM1D and TP53 predicted tMN evolution post-transplant. Notably, CH-derived tMN had worse outcomes than non CH-derived tMN. As such, screening for CH before aHSCT may inform individual patients' prognostic outcomes and influence their prospective treatment plans. Presented in part as an oral abstract at the 2022 American Society of Hematology Annual Meeting, New Orleans, LA, 2022.

MicroRNA Profiles in Hematopoietic Stem Cell Transplant Recipients

Background: Hematopoietic Stem Cell Transplant (HCT) is a potentially curative treatment for hematologic malignancies, including multiple myeloma. Biomarker investigation can guide identification of HCT recipients at-risk for poor outcomes. MicroRNAs (miRNAs) are a class of non-coding RNAs involved in the modulation and regulation of pathological processes and are emerging as prognostic and predictive biomarkers for multiple health conditions. This pilot study aimed to examine miRNA profiles associated with HCT-related risk factors and outcomes in patients undergoing autologous HCT. Methods: Patients eligible for autologous HCT were recruited and blood samples and HCT-related variables were collected. Differential expression analysis of miRNA was conducted on 24 patient samples to compare changes in miRNA profile in HCT eligible patients before and after transplant. Results: Unsupervised clustering of differentially expressed (p < .05) miRNAs pre- and post- HCT identified clusters of up- and down-regulated miRNAs. Four miRNAs (miR-125a-5p, miR-99b-5p, miR-382-5p, miR-145-5p) involved in hematopoiesis (differentiation of progenitor cells, granulocyte function, thrombopoiesis, and tumor suppression) were significantly downregulated post-HCT. Correlation analyses identified select miRNAs associated with risk factors (such as frailty, fatigue, cognitive decline) and quality of life pre- and post-HCT. Select miRNAs were correlated with platelet engraftment. Conclusion: Future studies should examine miRNA signatures in larger cohorts in association with HCT outcomes; and expand investigations in patients receiving allogeneic transplants. This will lead to identification of biomarkers for risk stratification of HCT recipients.

Single-Cell DNA Sequencing Reveals an Evolutionary Pattern of CHIP in Transplant Eligible Multiple Myeloma Patients

Clonal hematopoiesis of indeterminate potential (CHIP) refers to the phenomenon where a hematopoietic stem cell acquires fitness-increasing mutation(s), resulting in its clonal expansion. CHIP is frequently observed in multiple myeloma (MM) patients, and it is associated with a worse outcome. High-throughput amplicon-based single-cell DNA sequencing was performed on circulating CD34+ cells collected from twelve MM patients before autologous stem cell transplantation (ASCT). Moreover, in four MM patients, longitudinal samples either before or post-ASCT were collected. Single-cell sequencing and data analysis were assessed using the MissionBio Tapestri® platform, with a targeted panel of 20 leukemia-associated genes. We detected CHIP pathogenic mutations in 6/12 patients (50%) at the time of transplant. The most frequently mutated genes were TET2, EZH2, KIT, DNMT3A, and ASXL1. In two patients, we observed co-occurring mutations involving an epigenetic modifier (i.e., DNMT3A) and/or a gene involved in splicing machinery (i.e., SF3B1) and/or a tyrosine kinase receptor (i.e., KIT) in the same clone. Longitudinal analysis of paired samples revealed a positive selection of mutant high-fitness clones over time, regardless of their affinity with a major or minor sub-clone. Copy number analysis of the panel of all genes did not show any numerical alterations present in stem cell compartment. Moreover, we observed a tendency of CHIP-positive patients to achieve a suboptimal response to therapy compared to those without. A sub-clone dynamic of high-fitness mutations over time was confirmed.

Small myeloid subclones are present at diagnosis of multiple myeloma in patients who develop secondary myelodysplastic syndromes

Not available.

Bone marrow inflammation in haematological malignancies

Tissue inflammation is a hallmark of tumour microenvironments. In the bone marrow, tumour-associated inflammation impacts normal niches for haematopoietic progenitor cells and mature immune cells and supports the outgrowth and survival of malignant cells residing in these niche compartments. This Review provides an overview of our current understanding of inflammatory changes in the bone marrow microenvironment of myeloid and lymphoid malignancies, using acute myeloid leukaemia and multiple myeloma as examples and highlights unique and shared features of inflammation in niches for progenitor cells and plasma cells. Importantly, inflammation exerts profoundly different effects on normal bone marrow niches in these malignancies, and we provide context for possible drivers of these divergent effects. We explore the role of tumour cells in inflammatory changes, as well as the role of cellular constituents of normal bone marrow niches, including myeloid cells and stromal cells. Integrating knowledge of disease-specific dynamics of malignancy-associated bone marrow inflammation will provide a necessary framework for future targeting of these processes to improve patient outcome.

Pathophysiology of Acute Myeloid Leukemia

BACKGROUND

Acute myeloid leukemia (AML) is a biologically heterogenous disease arising in clonally proliferating hematopoietic stem cells. Sequential acquisition of mutations leads to expanded proliferation of clonal myeloid progenitors and failure of differentiation, leading to fulminant AML.

SUMMARY

Here, we review the pathophysiology of AML with a focus on factors predisposing to AML development, including prior chemo- and radiation therapy, environmental factors, and germline predisposition.

KEY MESSAGE

Increasing genomic characterization of AML and insight into mechanisms of its development will be critical to improvement in AML prognostication and therapy.

The crossroads of cancer therapies and clonal hematopoiesis

The intricate interplay between Clonal Hematopoiesis (CH) and the repercussions of cancer therapies has garnered significant research focus in recent years. Previously perceived as an age-related phenomenon, CH is now closely linked to inflammation ("Inflammaging") and cancer, impacting leukemogenesis, cancer progression, and treatment responses. This review explores the complex interplay between CH and diverse cancer therapies, including chemotherapy, targeted treatments, radiation, stem cell transplants, CAR-T cell therapy, and immunotherapy, like immune checkpoint inhibitors. Notably, knowledge about post-chemotherapy CH mutation/acquisition has evolved from a de novo incident to more of a clonal selection process. Chemotherapy and radiation exposure, whether therapeutic or environmental, increases CH risk, particularly in genes like TP53 and PPM1D. Environmental toxins, especially in high-risk environments like post-disaster sites or space exploration, are associated with CH. CH affects clinical outcomes in stem cell transplant scenarios, including engraftment, survival, and t-MN development. The presence of CH also alters CAR-T cell therapy responses and impacts the efficacy and toxicity of immunotherapies. Furthermore, specific mutations like DNMT3A and TET2 thrive under inflammatory stress, influencing therapy outcomes and justifying the ongoing tailored interventions in clinical trials. This review underscores the critical need to integrate CH analysis into personalized medicine, enhancing risk assessments and refining treatment strategies. As we progress, multidisciplinary collaboration and comprehensive studies are imperative. Understanding CH's impact, especially concerning genotoxic stressors, will inform screening, surveillance, and early detection strategies, decreasing the risk of therapy-related myeloid neoplasms and revolutionizing cancer treatment paradigms.

Clonal hematopoiesis in the setting of hematopoietic cell transplantation

Clonal hematopoiesis (CH) in autologous transplant recipients and allogeneic transplant donors has genetic features and clinical associations that are distinct from each other and from non-cancer populations. CH in the setting of autologous transplant is enriched for mutations in DNA damage response pathway genes and is associated with adverse outcomes, including an increased risk of therapy-related myeloid neoplasm and inferior overall survival. Studies of CH in allogeneic transplant donors have yielded conflicting results but have generally shown evidence of potentiated alloimmunity in recipients, with some studies showing an association with favorable recipient outcomes.

Prognostic relevance of clonal hematopoiesis in myeloid neoplastic transformation in patients with follicular lymphoma treated with radioimmunotherapy

While novel radioisotope therapies continue to advance cancer care, reports of therapy-related myeloid neoplasms (t-MN) have generated concern. The prevalence and role of clonal hematopoiesis (CH) in this process remain to be defined. We hypothesized that: (i) CH is prevalent in relapsed follicular lymphoma and is associated with t-MN transformation, and (ii) radiation in the form of radioimmunotherapy (RIT) plays a role in clonal progression. In this retrospective cohort study, we evaluated the prevalence and prognostic impact of CH on clinical outcomes in 58 heavily pre-treated follicular lymphoma patients who received RIT. Patients had been given a median of four lines of therapy before RIT. The prevalence of CH prior to RIT was 46%, while it was 67% (P=0.15) during the course of RIT and subsequent therapies in the paired samples. Fourteen (24%) patients developed t-MN. Patients with t-MN had a higher variant allele fraction (38% vs. 15%; P=0.02) and clonal complexity (P=0.03) than those without. The spectrum of CH differed from that in age-related CH, with a high prevalence of DNA damage repair and response pathway mutations, absence of spliceosome mutations, and a paucity of signaling mutations. While there were no clear clinical associations between RIT and t-MN, or overall survival, patients with t-MN had a higher mutant clonal burden, along with extensive chromosomal abnormalities (median survival, afer t-MN diagnosis, 0.9 months). The baseline prevalence of CH was high, with an increase in prevalence on exposure to RIT and subsequent therapies. The high rates of t-MN with marked clonal complexities and extensive chromosomal damage underscore the importance of better identifying and studying genotoxic stressors accentuated by therapeutic modalities.

Clonal Hematopoiesis and Cardiovascular Disease in Patients With Multiple Myeloma Undergoing Hematopoietic Cell Transplant

Importance

There is a paucity of information on the association between clonal hematopoiesis of indeterminate potential (CHIP) and cardiovascular disease (CVD) in patients with cancer, including those with multiple myeloma (MM) undergoing hematopoietic cell transplant (HCT), a population at high risk of developing CVD after HCT.

Objective

To examine the association between CHIP and CVD in patients with MM and to describe modifiers of CVD risk among those with CHIP.

Design, Setting, and Participants

This was a retrospective cohort study of patients with MM who underwent HCT between 2010 and 2016 at City of Hope Comprehensive Cancer Center in Duarte, California, and had pre-HCT mobilized peripheral blood stem cell (PBSC) products cryopreserved and accessible for CHIP analyses. The study team performed targeted panel DNA sequencing to detect the presence of CHIP (variant allele frequency 2% or more).

Main Outcomes and Measures

The primary end point was the 5-year cumulative incidence and risk for developing de novo CVD (heart failure, coronary artery disease, or stroke) after HCT.

Results

Of 1036 consecutive patients with MM (580 male [56%]; median age, 60.0 years) who underwent a first autologous HCT, 201 patients had at least 1 CHIP variant (19.4%) and 35 patients had 2 or more variants (3.4%). The 5-year incidence of CVD was significantly higher in patients with CHIP (21.1% vs 8.4%; P < .001) compared with those without CHIP; the 5-year incidence among those with 2 or more variants was 25.6%. In the multivariable model, CHIP was associated with increased risk of CVD (hazard ratio [HR], 2.72; 95% CI, 1.70-4.39), as well as of individual outcomes of interest, including heart failure (HR, 4.02; 95% CI, 2.32-6.98), coronary artery disease (HR, 2.22; 95% CI, 1.06-4.63), and stroke (HR, 3.02; 95% CI, 1.07-8.52). Patients who had both CHIP and preexisting hypertension or dyslipidemia were at nearly 7-fold and 4-fold increased risk of CVD, respectively (reference: no CHIP, no hypertension, or dyslipidemia).

Conclusion and Relevance

CHIP was significantly and independently associated with risk of CVD in patients with MM undergoing HCT and may serve as a novel biologically plausible biomarker for CVD in this cohort. Patients with MM and both CHIP and cardiovascular risk factors had an exceptionally high risk of CVD. Additional studies are warranted to determine if cardiovascular preventive measures can reduce CHIP-associated CVD risk.

Causes and consequences of clonal hematopoiesis

ABSTRACT

Clonal hematopoiesis (CH) is described as the outsized contribution of expanded clones of hematopoietic stem and progenitor cells (HSPCs) to blood cell production. The prevalence of CH increases dramatically with age. CH can be caused by somatic mutations in individual genes or by gains and/or losses of larger chromosomal segments. CH is a premalignant state; the somatic mutations detected in CH are the initiating mutations for hematologic malignancies, and CH is a strong predictor of the development of blood cancers. Moreover, CH is associated with nonmalignant disorders and increased overall mortality. The somatic mutations that drive clonal expansion of HSPCs can alter the function of terminally differentiated blood cells, including the release of elevated levels of inflammatory cytokines. These cytokines may then contribute to a broad range of inflammatory disorders that increase in prevalence with age. Specific somatic mutations in the peripheral blood in coordination with blood count parameters can powerfully predict the development of hematologic malignancies and overall mortality in CH. In this review, we summarize the current understanding of CH nosology and origins. We provide an overview of available tools for risk stratification and discuss management strategies for patients with CH presenting to hematology clinics.

Clinical Outcomes and Evolution of Clonal Hematopoiesis in Patients with Newly Diagnosed Multiple Myeloma

Clonal hematopoiesis (CH) at time of autologous stem cell transplant (ASCT) has been shown to be associated with decreased overall survival (OS) and progression-free survival (PFS) in patients with multiple myeloma not receiving immunomodulatory drugs (IMiD). However, the significance of CH in newly diagnosed patients, including transplant ineligible patients, and its effect on clonal evolution during multiple myeloma therapy in the era of novel agents, has not been well studied. Using our new algorithm to differentiate tumor and germline mutations from CH, we detected CH in approximately 10% of 986 patients with multiple myeloma from the Clinical Outcomes in MM to Personal Assessment of Genetic Profile (CoMMpass) cohort (40/529 transplanted and 59/457 non-transplanted patients). CH was associated with increased age, risk of recurrent bacterial infections and cardiovascular disease. CH at time of multiple myeloma diagnosis was not associated with inferior OS or PFS regardless of undergoing ASCT, and all patients benefited from IMiD-based therapies, irrespective of the presence of CH. Serial sampling of 52 patients revealed the emergence of CH over a median of 3 years of treatment, increasing its prevalence to 25%, mostly with DNMT3A mutations.

SIGNIFICANCE

Using our algorithm to differentiate tumor and germline mutations from CH mutations, we detected CH in approximately 10% of patients with newly diagnosed myeloma, including both transplant eligible and ineligible patients. Receiving IMiDs improved outcomes irrespective of CH status, but the prevalence of CH significantly rose throughout myeloma-directed therapy.

Molecular and clinical aspects relevant for counseling individuals with clonal hematopoiesis of indeterminate potential

Clonal hematopoiesis of indeterminate potential (CHIP) has fascinated the medical community for some time. Discovered about a decade ago, this phenomenon links age-related alterations in hematopoiesis not only to the later development of hematological malignancies but also to an increased risk of early-onset cardiovascular disease and some other disorders. CHIP is detected in the blood and is characterized by clonally expanded somatic mutations in cancer-associated genes, predisposing to the development of hematologic neoplasms such as MDS and AML. CHIP-associated mutations often involve DNA damage repair genes and are frequently observed following prior cytotoxic cancer therapy. Genetic predisposition seems to be a contributing factor. It came as a surprise that CHIP significantly elevates the risk of myocardial infarction and stroke, and also contributes to heart failure and pulmonary hypertension. Meanwhile, evidence of mutant clonal macrophages in vessel walls and organ parenchyma helps to explain the pathophysiology. Besides aging, there are some risk factors promoting the appearance of CHIP, such as smoking, chronic inflammation, chronic sleep deprivation, and high birth weight. This article describes fundamental aspects of CHIP and explains its association with hematologic malignancies, cardiovascular disorders, and other medical conditions, while also exploring potential progress in the clinical management of affected individuals. While it is important to diagnose conditions that can lead to adverse, but potentially preventable, effects, it is equally important not to stress patients by confronting them with disconcerting findings that cannot be remedied. Individuals with diagnosed or suspected CHIP should receive counseling in a specialized outpatient clinic, where professionals from relevant medical specialties may help them to avoid the development of CHIP-related health problems. Unfortunately, useful treatments and clinical guidelines for managing CHIP are still largely lacking. However, there are some promising approaches regarding the management of cardiovascular disease risk. In the future, strategies aimed at restoration of gene function or inhibition of inflammatory mediators may become an option.

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

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

Good Cop, Bad Cop: Profiling the Immune Landscape in Multiple Myeloma

Multiple myeloma (MM) is a dyscrasia of plasma cells (PCs) characterized by abnormal immunoglobulin (Ig) production. The disease remains incurable due to a multitude of mutations and structural abnormalities in MM cells, coupled with a favorable microenvironment and immune suppression that eventually contribute to the development of drug resistance. The bone marrow microenvironment (BMME) is composed of a cellular component comprising stromal cells, endothelial cells, osteoclasts, osteoblasts, and immune cells, and a non-cellular component made of the extracellular matrix (ECM) and the liquid milieu, which contains cytokines, growth factors, and chemokines. The bone marrow stromal cells (BMSCs) are involved in the adhesion of MM cells, promote the growth, proliferation, invasion, and drug resistance of MM cells, and are also crucial in angiogenesis and the formation of lytic bone lesions. Classical immunophenotyping in combination with advanced immune profiling using single-cell sequencing technologies has enabled immune cell-specific gene expression analysis in MM to further elucidate the roles of specific immune cell fractions from peripheral blood and bone marrow (BM) in myelomagenesis and progression, immune evasion and exhaustion mechanisms, and development of drug resistance and relapse. The review describes the role of BMME components in MM development and ongoing clinical trials using immunotherapeutic approaches.

Aiming for the cure in myeloma: Putting our best foot forward

Frontline therapy for multiple myeloma (MM) is evolving to include novel combinations that can achieve unprecedented deep response rates. Several treatment strategies exist, varying in induction regimen composition, use of transplant and or consolidation and maintenance. In this sea of different treatment permutations, the overarching theme is the powerful prognostic factors of disease risk and achievement of minimal residual disease (MRD) negativity. MM has significant inter-patient variability that requires treatment to be individualized. Risk-adapted and response-adapted strategies which are increasingly being explored to define the extent and duration of therapy, and eventually aim for functional curability. In addition, with T-cell redirection therapies rapidly revolutionizing myeloma treatments, the current standard of care for myeloma will change. This review analyzes the current relevant literature in upfront therapy for fit myeloma patients and provides suggestions for treatment approach while novel clinical trials are maturing.

Pooled ctDNA analysis of MONALEESA phase III advanced breast cancer trials

BACKGROUND

The phase III MONALEESA trials tested the efficacy and safety of the cyclin-dependent kinase (CDK)4/6 inhibitor ribociclib with different endocrine therapy partners as first- or second-line treatment of hormone receptor-positive/human epidermal growth factor receptor 2-negative advanced breast cancer (ABC). Using the largest pooled biomarker dataset of the CDK4/6 inhibitor ribociclib in ABC to date, we identified potential biomarkers of response to ribociclib.

PATIENTS AND METHODS

Baseline circulating tumour DNA from patients in the MONALEESA trials was assessed using next-generation sequencing. An analysis of correlation between gene alteration status and progression-free survival (PFS) was carried out to identify potential biomarkers of response to ribociclib.

RESULTS

Multiple frequently altered genes were identified. Alterations in ERBB2, FAT3, FRS2, MDM2, SFRP1, and ZNF217 were associated with a greater PFS benefit with ribociclib versus placebo. Patients with high tumour mutational burden (TMB) and with ANO1, CDKN2A/2B/2C, and RB1 alterations exhibited decreased sensitivity to ribociclib versus placebo.

CONCLUSIONS

Although exploratory, these results provide insight into alterations associated with the improved response to ribociclib treatment and may inform treatment sequencing in patients with actionable alterations following progression on CDK4/6 inhibitors. Validation of potential biomarkers identified here and development of prospective trials testing their clinical utility are warranted.

CLINICALTRIALS

GOV IDENTIFIERS

NCT01958021, NCT02422615, NCT02278120.

The Impact of CD34+ Cell Collection Yields for Autologous Transplant on Survival Outcomes in Multiple Myeloma

INTRODUCTION

According to previous data, higher yields of stem-cells collected to support autologous transplantation may predict for improved outcomes. We aimed to assess the association between high stem-cells collection and survival outcomes in multiple myeloma (MM) MATERIALS AND METHODS: We reviewed all patients who underwent autologous transplantation for MM at our center over a 10-year period, and initially used a predefined threshold of 8 × 106/kg used in previous studies.

RESULTS

Six hundred twenty-one patients were analyzed. Higher mobilization did not correlate with favorable outcomes post-transplant. The most efficient mobilizers, collecting ≥8 × 106/kg (n = 478) achieved a shorter median progression-free survival (PFS) of 24.1m versus 34.5m in patients collecting 4.5 to 8 × 106/kg (n = 129). A small group (n = 14) collecting ≤4.5 × 106/kg but minimum of 2 × 106/kg to support autologous transplantation exhibited the worst outcomes (median PFS 11.4m). Further analysis of potential confounders identified greater use of bortezomib induction in the lower mobilizers, however, sensitivity analysis in patients receiving bortezomib revealed similar results- worst outcomes to the most efficient mobilizers.

CONCLUSION

Although bortezomib is not considered stem-cell toxic, it may be associated with lower stem cell collection yields. Bortezomib's efficacy at induction may partially explain the improved outcomes, however, other factors may be involved, and are discussed. We can conclude that with our large cohort and long follow-up, high stem-cell mobilization does not appear to predict for a long-term survival advantage.

Clonal haematopoiesis - a novel entity that modifies pathological processes in elderly

Progress in the development of new sequencing techniques with wider accessibility and higher sensitivity of the protocol of deciphering genome particularities led to the discovery of a new phenomenon - clonal haematopoiesis. It is characterized by the presence in the bloodstream of elderly people a minor clonal population of cells with mutations in certain genes, but without any sign of disease related to the hematopoietic system. Here we will review this recent advancement in the field of clonal haematopoiesis and how it may affect the disease's development in old age.

Single-cell multi-omics defines the cell-type-specific impact of splicing aberrations in human hematopoietic clonal outgrowths

RNA splicing factors are recurrently mutated in clonal blood disorders, but the impact of dysregulated splicing in hematopoiesis remains unclear. To overcome technical limitations, we integrated genotyping of transcriptomes (GoT) with long-read single-cell transcriptomics and proteogenomics for single-cell profiling of transcriptomes, surface proteins, somatic mutations, and RNA splicing (GoT-Splice). We applied GoT-Splice to hematopoietic progenitors from myelodysplastic syndrome (MDS) patients with mutations in the core splicing factor SF3B1. SF3B1mut cells were enriched in the megakaryocytic-erythroid lineage, with expansion of SF3B1mut erythroid progenitor cells. We uncovered distinct cryptic 3' splice site usage in different progenitor populations and stage-specific aberrant splicing during erythroid differentiation. Profiling SF3B1-mutated clonal hematopoiesis samples revealed that erythroid bias and cell-type-specific cryptic 3' splice site usage in SF3B1mut cells precede overt MDS. Collectively, GoT-Splice defines the cell-type-specific impact of somatic mutations on RNA splicing, from early clonal outgrowths to overt neoplasia, directly in human samples.

Outcome of Second Primary Malignancies Developing in Multiple Myeloma Patients

BACKGROUND

There is an increased risk of second primary malignancies (SMPs) in patients with multiple myeloma (MM). This multinational 'real-world' retrospective study analyzed the characteristics and outcomes of MM patients that developed SPMs.

RESULTS

165 patients were analyzed: 62.4% males; 8.5% with a prior cancer; 113 with solid SPMs, mainly ≥stage 2; and 52 with hematological SPM (hemato-SPM), mainly MDS/AML. Patients with hemato-SPM were younger (p = 0.05) and more frequently had a prior AutoHCT (p = 0.012). The time to SPM was shorter in the older (>65 years) and more heavily pretreated patients. One hundred patients were actively treated at the time of SPM detection. Treatment was discontinued in 52, substituted with another anti-MM therapy in 15, and continued in 33 patients. Treatment discontinuation was predominant in the patients diagnosed with hemato-SPM (76%). The median OS following SPM detection was 8.5 months, and the main cause of death was SPM. A poor ECOG status predicted a shorter OS (PS 3 vs. 0, HR = 5.74, 2.32-14.21, p < 0.001), whereas a normal hemoglobin level (HR = 0.43, 0.19-0.95, p = 0.037) predicted longer OS.

CONCLUSIONS

With the continuing improvement in OS, a higher proportion of MM patients might develop SPM. The OS following SPM diagnosis is poor; hence, frequent surveillance and early detection are imperative to improve outcomes.

Current clinical practices and challenges in molecular testing: a GOAL Consortium Hematopathology Working Group report

While molecular testing of hematologic malignancies is now standard of care, there is variability in practice and testing capabilities between different academic laboratories, with common questions arising on how to best meet clinical expectations. A survey was sent to hematopathology subgroup members of the Genomics Organization for Academic Laboratories consortium to assess current and future practice and potentially establish a reference for peer institutions. Responses were received from 18 academic tertiary-care laboratories regarding next-generation sequencing (NGS) panel design, sequencing protocols and metrics, assay characteristics, laboratory operations, case reimbursement, and development plans. Differences in NGS panel size, use, and gene content were reported. Gene content for myeloid processes was reported to be generally excellent, while genes for lymphoid processes were less well covered. The turnaround time (TAT) for acute cases, including acute myeloid leukemia, was reported to range from 2 to 7 calendar days to 15 to 21 calendar days, with different approaches to achieving rapid TAT described. To help guide NGS panel design and standardize gene content, consensus gene lists based on current and future NGS panels in development were generated. Most survey respondents expected molecular testing at academic laboratories to continue to be viable in the future, with rapid TAT for acute cases likely to remain an important factor. Molecular testing reimbursement was reported to be a major concern. The results of this survey and subsequent discussions improve the shared understanding of differences in testing practices for hematologic malignancies between institutions and will help provide a more consistent level of patient care.

Clonal Hematopoiesis in Young Women Treated for Breast Cancer

PURPOSE

Young women treated for breast cancer with cytotoxic therapies are at risk for clonal hematopoiesis of indeterminate potential (CHIP), a condition in which blood cells carrying a somatic mutation associated with hematologic malignancy comprise at least 4% of the total blood system. CHIP has primarily been studied in older patient cohorts with limited clinical phenotyping.

EXPERIMENTAL DESIGN

We performed targeted sequencing on longitudinal blood samples to characterize the clonal hematopoietic landscape of 878 women treated for breast cancer enrolled in the prospective Young Women's Breast Cancer Study.

RESULTS

We identified somatic driver mutations in 252 study subjects (28.7%), but only 24 (2.7%) had clones large enough to meet criteria for CHIP. The most commonly mutated genes were DNMT3A and TET2, similar to mutations observed in noncancer cohorts. At 9-year median follow-up, we found no association between the presence of a somatic blood mutation (regardless of clone size) and adverse breast cancer (distant relapse-free survival) or non-breast cancer-related outcomes in this cohort. A subset of paired blood samples obtained over 4 years showed no evidence of mutant clonal expansion, regardless of genotype. Finally, we identified a subset of patients with likely germline mutations in genes known to contribute to inherited cancer risk, such as TP53 and ATM.

CONCLUSIONS

Our data show that for young women with early-stage breast cancer, CHIP is uncommon after cytotoxic exposure, is unlikely to contribute to adverse outcomes over the decade-long follow-up and may not require additional monitoring if discovered incidentally.

Clonal Myeloid Dysplasia Following CAR T-Cell Therapy: Chicken or the Egg?

Multiple myeloma (MM) is characterized by recurrent relapses. Consequently, patients receive multiple therapy lines, including alkylating agents and immune modulators, which have been associated with secondary malignancies such as myelodysplastic syndrome (MDS). Anti-B-cell maturation antigen (BCMA) chimeric antigen receptor T cell (CART) therapy is efficacious in patients with relapsed/refractory (R/R) MM. However, the long-term complications, particularly MDS, are not well understood. Whether CART therapy causes or promotes MDS has not been thoroughly investigated. In this study, we explored the causal relationship between MDS and CART therapy. We retrospectively examined the prevalence of MDS-related morphological and mutational changes before and after administration of CART therapy in five patients. Among them, four developed MDS after CART therapy, while one had pre-existing MDS prior to CART. None of the four patients who developed post-CART MDS showed morphological MDS changes prior to CART therapy. However, all four patients exhibited molecular alterations associated with MDS in their pre-CART as well as post-CART therapy bone marrow. No new mutations were observed. Our findings provide initial evidence suggesting that anti-BCMA CART therapy in MM may promote expansion of pre-existing MDS clones rather than causing development of new clones.

TP53-Mutated Myelodysplasia and Acute Myeloid Leukemia

TP53-mutated myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) form a distinct and heterogeneous group of myeloid malignancies associated with poor outcomes. Studies carried out in the last years have in part elucidated the complex role played by TP53 mutations in the pathogenesis of these myeloid disorders and in the mechanisms of drug resistance. A consistent number of studies has shown that some molecular parameters, such as the presence of a single or multiple TP53 mutations, the presence of concomitant TP53 deletions, the association with co-occurring mutations, the clonal size of TP53 mutations, the involvement of a single (monoallelic) or of both TP53 alleles (biallelic) and the cytogenetic architecture of concomitant chromosome abnormalities are major determinants of outcomes of patients. The limited response of these patients to standard treatments, including induction chemotherapy, hypomethylating agents and venetoclax-based therapies and the discovery of an immune dysregulation have induced a shift to new emerging therapies, some of which being associated with promising efficacy. The main aim of these novel immune and nonimmune strategies consists in improving survival and in increasing the number of TP53-mutated MDS/AML patients in remission amenable to allogeneic stem cell transplantation.

Outcomes and long-term effects of hematopoietic stem cell transplant in sickle cell disease

INTRODUCTION

Hematopoietic stem cell transplant (HSCT) is the only readily available curative option for sickle cell disease (SCD). Cure rates following human leukocyte antigen (HLA)-matched related donor HSCT with myeloablative or non-myeloablative conditioning are >90%. Alternative donor sources, including haploidentical donor and autologous with gene therapy, expand donor options but are limited by inferior outcomes, limited data, and/or shorter follow-up and therefore remain experimental.

AREAS COVERED

Outcomes are improving with time, with donor type and conditioning regimens having the greatest impact on long-term complications. Patients with stable donor engraftment do not experience SCD-related symptoms and have stabilization or improvement of end-organ pathology; however, the long-term effects of curative strategies remain to be fully established and have significant implications in a patient's decision to seek therapy. This review covers currently published literature on HSCT outcomes, including organ-specific outcomes implicated in SCD, as well as long-term effects.

EXPERT OPINION

HSCT, both allogeneic and autologous gene therapy, in the SCD population reverses the sickle phenotype, prevents further organ damage, can resolve prior organ dysfunction in both pediatric and adult patients. Data support greater success with HSCT at a younger age, thus, curative therapies should be discussed early in the patient's life.

Clinicopathologic Features of Therapy-Related Myeloid Neoplasms in Patients with Myeloma in the Era of Novel Therapies

The development of therapy-related myeloid neoplasms (t-MN) is a rare complication that can occur in myeloma patients treated primarily with novel therapies. To better understand t-MNs in this context, we reviewed 66 such patients and compared them with a control group of patients who developed t-MN after cytotoxic therapies for other malignancies. The study group included 50 men and 16 women, with a median age of 68 years (range, 48-86 years). Therapies included proteasome inhibitors, immunomodulatory agents, and high-dose melphalan-based autologous stem cell transplantation (HDM-ASCT) in 64 (97%), 65 (98.5%), and 64 (97%) patients, respectively; 29 (43.9%) patients were exposed to other cytotoxic drugs besides HDM. The latency interval from therapy to t-MN was 4.9 years (range, 0.6-21.9 years). Patients who received HDM-ASCT in addition to other cytotoxic therapies had a longer latency period to t-MN compared with patients who only received HDM-ASCT (6.1 vs 4.7 years, P = .009). Notably, 11 patients developed t-MN within 2 years. Therapy-related myelodysplastic syndrome was the most common type of neoplasm (n = 60), followed by therapy-related acute myeloid leukemia (n = 4) and myelodysplastic syndrome/myeloproliferative neoplasm (n = 2). The most common cytogenetic aberrations included complex karyotypes (48.5%), del7q/-7 (43.9%), and/or del5q/-5 (40.9%). The most frequent molecular alteration was TP53 mutation, in 43 (67.2%) patients and the sole mutation in 20 patients. Other mutations included DNMT3A, 26.6%; TET2, 14.1%; RUNX1, 10.9%; ASXL1, 7.8%; and U2AF1, 7.8%. Other mutations in less than 5% of cases included SRSF2, EZH2, STAG2, NRAS, SETBP, SF3B1, SF3A1, and ASXL2. After a median follow-up of 15.3 months, 18 patients were alive and 48 died. The median overall survival after the diagnosis of t-MN in the study group was 18.4 months. Although the overall features are comparable to the control group, the short interval to t-MN (<2 years) underscores the unique vulnerable status of myeloma patients.

Tracking the evolution of therapy-related myeloid neoplasms using chemotherapy signatures

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.

Clonal Hematopoiesis of Indeterminate Potential Is Associated With Coronary Microvascular Dysfunction In Early Nonobstructive Coronary Artery Disease

BACKGROUND

Clonal hematopoiesis (CH) of indeterminate potential (CHIP) is a risk factor for cardiovascular disease. The relationship between CHIP and coronary microvascular dysfunction (CMD) is unknown. The current study examines the association between CHIP and CH with CMD and the potential relationships in risk for adverse cardiovascular outcomes.

METHODS

In this retrospective observational study, targeted next-generation sequencing was performed for 177 participants with no coronary artery disease who presented with chest pain and underwent routine coronary functional angiogram. Patients with somatic mutations in leukemia-associated driver genes in hematopoietic stem and progenitor cells were examined; CHIP was considered at a variant allele fraction ≥2%; CH was considered at a variant allele fraction ≥1%. CMD was defined as coronary flow reserve to intracoronary adenosine of ≤2. Major adverse cardiovascular events considered were myocardial infarction, coronary revascularization, or stroke.

RESULTS

A total of 177 participants were examined. Mean follow-up was 12±7 years. A total of 17 patients had CHIP and 28 had CH. Cases with CMD (n=19) were compared with controls with no CMD (n=158). Cases were 56±9 years, were 68% women, and had more CHIP (27%; P=0.028) and CH (42%; P=0.001) than controls. CMD was associated with independent risk for major adverse cardiovascular events (hazard ratio, 3.89 [95% CI, 1.21-12.56]; P=0.023), and 32% of this risk was mediated by CH. The risk mediated by CH was ≈0.5× as large as the direct effect of CMD on major adverse cardiovascular events.

CONCLUSIONS

In humans, we observe patients with CMD are more likely to have CHIP, and nearly one-third of major adverse cardiovascular events in CMD are mediated by CH.

Synthetic lethal targeting of TET2-mutant haematopoietic stem and progenitor cells by XPO1 inhibitors

TET2 inactivating mutations serve as initiating genetic lesions in the transformation of haematopoietic stem and progenitor cells (HSPCs). In this study, we analysed known drugs in zebrafish embryos for their ability to selectively kill tet2-mutant HSPCs in vivo. We found that the exportin 1 (XPO1) inhibitors, selinexor and eltanexor, selectively kill tet2-mutant HSPCs. In serial replating colony assays, these small molecules were selectively active in killing murine Tet2-deficient Lineage-, Sca1+, Kit+ (LSK) cells, and also TET2-inactivated human acute myeloid leukaemia (AML) cells. Selective killing of TET2-mutant HSPCs and human AML cells by these inhibitors was due to increased levels of apoptosis, without evidence of DNA damage based on increased γH2AX expression. The finding that TET2 loss renders HSPCs and AML cells selectively susceptible to cell death induced by XPO1 inhibitors provides preclinical evidence of the selective activity of these drugs, justifying further clinical studies of these small molecules for the treatment of TET2-mutant haematopoietic malignancies, and to suppress clonal expansion in age-related TET2-mutant clonal haematopoiesis.

Klonale Hämatopoese (CHIP) und klonale Zytopenie unbestimmter Signifikanz (CCUS)

Clonal hematopoiesis of indeterminate potential (CHIP) refers to the outgrowth of blood cells from a hematopoietic stem cell (HSC) clone that acquired one or more somatic mutations, leading to a growth advantage compared to wild type HSCs. In the last years this age-associated phenomenon has been extensively studied, and several cohort studies found association between CH and age-related diseases, esp. leukaemia and cardiovascular disease. For patients with CH present with abnormal blood counts, the term 'clonal cytopenia of unknown significance' is used, which carries a higher risk for developing myeloid neoplasms. In this year, CHIP and CCUS have been included in the updated WHO classification of hematolymphoid tumours. We review the current understanding of the emergence of CHIP, diagnostics, association with other diseases, and potential therapeutic interventions.

Clonal hematopoiesis detection in patients with cancer using cell-free DNA sequencing

In the context of cancer, clonal hematopoiesis of indeterminate potential (CHIP) is associated with the development of therapy-related myeloid neoplasms and shorter overall survival. Cell-free DNA (cfDNA) sequencing is becoming widely adopted for genomic screening of patients with cancer but has not been used extensively to determine CHIP status because of a requirement for matched blood and tumor sequencing. We present an accurate classification approach to determine the CH status from cfDNA sequencing alone, applying our model to 4324 oncology clinical cfDNA samples. Using this method, we determined that 30.3% of patients in this cohort have evidence of CH, and the incidence of CH varies by tumor type. Matched RNA sequencing data show evidence of increased inflammation, especially neutrophil activation, within the tumors and tumor microenvironments of patients with CH. In addition, patients with CH had evidence of neutrophil activation systemically, pointing to a potential mechanism of action for the worse outcomes associated with CH status. Neutrophil activation may be one of many mechanisms, however, because patients with estrogen receptor-positive breast cancer harboring TET2 frameshift mutations had worse outcomes but similar neutrophil frequencies to patients without CH. Together, these data show the feasibility of detecting CH through cfDNA sequencing alone and an application of this method, demonstrating increased inflammation in patients with CH both systemically and in the tumor microenvironment.

Clonal Hematopoiesis and the Heart: a Toxic Relationship

PURPOSE OF REVIEW

Clonal hematopoiesis (CH) refers to the expansion of hematopoietic stem cell clones and their cellular progeny due to somatic mutations, mosaic chromosomal alterations (mCAs), or copy number variants which naturally accumulate with age. CH has been linked to increased risk of blood cancers, but CH has also been linked to adverse cardiovascular outcomes.

RECENT FINDINGS

A combination of clinical outcome studies and mouse models have offered strong evidence that CH mutations either correlate with or cause atherosclerosis, diabetes mellitus, chronic kidney disease, heart failure, pulmonary hypertension, aortic aneurysm, myocardial infarction, stroke, aortic stenosis, poor outcomes following transcatheter aortic valve replacement (TAVR) or orthotopic heart transplant, death or need of renal replacement therapy secondary to cardiogenic shock, death from cardiovascular causes at large, and enhance anthracycline cardiac toxicity. Mechanistically, some adverse outcomes are caused by macrophage secretion of IL-1β and IL-6, neutrophil invasion of injured myocardium, and T-cell skewing towards inflammatory phenotypes. CH mutations lead to harmful inflammation and arterial wall invasion by bone marrow-derived cells resulting in poor cardiovascular health and outcomes. Blockade of IL-1β or JAK2 signaling are potential avenues for preventing CH-caused cardiovascular morbidity and mortality.

CHIPing away the progression potential of CHIP: A new reality in the making

Over the past few years, we have gained a deeper understanding of clonal hematopoiesis of indeterminate potential (CHIP), especially with regard to the epidemiology, clinical sequelae, and mechanical aspects. However, interventional strategies to prevent or delay the potential negative consequences of CHIP remain underdeveloped. In this review, we highlight the latest updates on clonal hematopoiesis research, including molecular mechanisms and clinical implications, with a particular focus on the evolving strategies for the interventions that are being evaluated in ongoing observational and interventional trials. There remains an urgent need to formulate standardized and evidence-based recommendations and guidelines for evaluating and managing individuals with clonal hematopoiesis. In addition, patient-centric endpoints must be defined for clinical trials, which will enable us to continue the robust development of effective preventive strategies and improve clinical outcomes.

Therapy-selected clonal hematopoiesis and its role in myeloid neoplasms

Therapy-related myeloid neoplasms (t-MN) account for approximately 10-15% of all myeloid neoplasms and are associated with poor prognosis. Genomic characterization of t-MN to date has been limited in comparison to the considerable sequencing efforts performed for de novo myeloid neoplasms. Until recently, targeted deep sequencing (TDS) or whole exome sequencing (WES) have been the primary technologies utilized and thus limited the ability to explore the landscape of structural variants and mutational signatures. In the past decade, population-level studies have identified clonal hematopoiesis as a risk factor for the development of myeloid neoplasms. However, emerging research on clonal hematopoiesis as a risk factor for developing t-MN is evolving, and much is unknown about the progression of CH to t-MN. In this work, we will review the current knowledge of the genomic landscape of t-MN, discuss background knowledge of clonal hematopoiesis gained from studies of de novo myeloid neoplasms, and examine the recent literature studying the role of therapeutic selection of CH and its evolution under the effects of antineoplastic therapy. Finally, we will discuss the potential implications on current clinical practice and the areas of focus needed for future research into therapy-selected clonal hematopoiesis in myeloid neoplasms.

Monoclonal Gammopathy of Undetermined Significance: A Comprehensive Review

Monoclonal Gammopathy of Undetermined Significance (MGUS) is an asymptomatic premalignant plasma cell dyscrasia with a predominate rise of the IgG immunoglobulin fraction without end-organ damage, often diagnosed incidentally. Despite its progression into various subsequent forms of hematological malignancies, MGUS remains underdiagnosed. A literature search was conducted using the Medline, Cochrane, Embase, and Google Scholar databases, including articles published until December 2022. Keywords used encompassed "Monoclonal Gammopathy of Undetermined Significance," "Plasma Cell dyscrasia," "Monoclonal gammopathy of renal significance," and "IgM Monoclonal gammopathy of Undetermined Significance," This study aimed to conduct a critical review to update knowledge regarding the pathophysiology, risk factors, clinical features, diagnostic protocols, complications, and current and novel treatments for MGUS. We recommend a multidisciplinary approach to manage MGUS due to the complexity of the illness's etiology, diagnosis, and therapy. This comprehensive review also highlights future prospects, such as developing screening protocols for at-risk populations, prevention of disease progression by early diagnosis through genome-wide association studies, and management using Daratumumab and NSAIDs.