Search

Background: CART therapy has produced a paradigm shift in the treatment of relapsing FL patients. Strategies to optimize disease surveillance after these therapies are increasingly necessary. This study explores the potential value of ctDNA monitoring with an innovative signature of personalized trackable mutations., Method: Eleven FL patients treated with anti-CD19 CAR T-cell therapy were included. One did not respond and was excluded. Genomic profiling was performed before starting lymphodepleting chemotherapy to identify somatic mutations suitable for LiqBio-MRD monitoring. The dynamics of the baseline mutations (4.5 per patient) were further analyzed on 59 cfDNA follow-up samples. PET/CT examinations were performed on days +90, +180, +365, and every six months until disease progression or death., Results: After a median follow-up of 36 months, all patients achieved a CR as the best response. Two patients progressed. The most frequently mutated genes were CREBBP, KMT2D and EP300. Simultaneous analysis of ctDNA and PET/CT was available for 18 time-points. When PET/CT was positive, two out of four ctDNA samples were LiqBio-MRD negative. These two negative samples corresponded to women with a unique mesenteric mass in two evaluations and never relapsed. Meanwhile, 14 PET/CT negative images were mutation-free based on our LiqBio-MRD analysis (100%). None of the patients had a negative LiqBio-MRD test by day +7. Interestingly, all durably responding patients had undetectable ctDNA at or around three months after infusion. Two patients presented discordant results by PET/CT and ctDNA levels. No progression was confirmed in these cases. All the progressing patients were LiqBio-MRD positive before progression., Conclusion: This is a proof-of-principle for using ctDNA to monitor response to CAR T-cell therapy in FL. Our results confirm that a non-invasive liquid biopsy MRD analysis may correlate with response and could be used to monitor response. Harmonized definitions of ctDNA molecular response and pinpointing the optimal timing for assessing ctDNA responses are necessary for this setting. If using ctDNA analysis, we suggest restricting follow-up PET/CT in CR patients to a clinical suspicion of relapse, to avoid false-positive results., Competing Interests: AMM, SD, YRH, LR and MR are are employees of Altum Sequencing Co. RA, JM-L, and SB are equity shareholders of Altum Sequencing Co. CW is an employee of Hosea Precision Medical Technology Co. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Jiménez-Ubieto, Martín-Muñoz, Poza, Dorado, García-Ortiz, Revilla, Sarandeses, Ruiz-Heredia, Baumann, Rodríguez, Calbacho, Sánchez, Pina, García-Sancho, Figaredo, Rufián, Rodríguez, Carneros, Martínez-Laperche, Bastos-Oreiro, Wang, Cedena, Rapado, de Toledo, Valeri, Ayala, Martínez-López and Barrio.)

In the present study, we screened 84 Follicular Lymphoma patients for somatic mutations suitable as liquid biopsy MRD biomarkers using a targeted next-generation sequencing (NGS) panel. We found trackable mutations in 95% of the lymph node samples and 80% of the liquid biopsy baseline samples. Then, we used an ultra-deep sequencing approach with 2 · 10 -4 sensitivity (LiqBio-MRD) to track those mutations on 151 follow-up liquid biopsy samples from 54 treated patients. Positive LiqBio-MRD at first-line therapy correlated with a higher risk of progression both at the interim evaluation (HR INT 11.0, 95% CI 2.10-57.7, p = 0.005) and at the end of treatment (HR EOT , HR 19.1, 95% CI 4.10-89.4, p < 0.001). Similar results were observed by PET/CT Deauville score, with a median PFS of 19 months vs. NR (p < 0.001) at the interim and 13 months vs. NR (p < 0.001) at EOT. LiqBio-MRD and PET/CT combined identified the patients that progressed in less than two years with 88% sensitivity and 100% specificity. Our results demonstrate that LiqBio-MRD is a robust and non-invasive approach, complementary to metabolic imaging, for identifying FL patients at high risk of failure during the treatment and should be considered in future response-adapted clinical trials., (© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)

For the treatment of Multiple Myeloma, proteasome inhibitors are highly efficient and widely used, but resistance is a major obstacle to successful therapy. Several underlying mechanisms have been proposed but were only reported for a minority of resistant patients. The proteasome is a large and complex machinery. Here, we focus on the AAA ATPases of the 19S proteasome regulator ( PSMC1-6 ) and their implication in PI resistance. As an example of cancer evolution and the acquisition of resistance, we conducted an in-depth analysis of an index patient by applying FISH, WES, and immunoglobulin-rearrangement sequencing in serial samples, starting from MGUS to newly diagnosed Multiple Myeloma to a PI-resistant relapse. The WES analysis uncovered an acquired PSMC2 Y429S mutation at the relapse after intensive bortezomib-containing therapy, which was functionally confirmed to mediate PI resistance. A meta-analysis comprising 1499 newly diagnosed and 447 progressed patients revealed a total of 36 SNVs over all six PSMC genes that were structurally accumulated in regulatory sites for activity such as the ADP/ATP binding pocket. Other alterations impact the interaction between different PSMC subunits or the intrinsic conformation of an individual subunit, consequently affecting the folding and function of the complex. Interestingly, several mutations were clustered in the central channel of the ATPase ring, where the unfolded substrates enter the 20S core. Our results indicate that PSMC SNVs play a role in PI resistance in MM.

Purpose: Proteasome inhibitors (PI) are the backbone of various treatment regimens in multiple myeloma. We recently described the first in-patient point mutations affecting the 20S subunit PSMB5 underlying PI resistance. Notably, in vivo, the incidence of mutations in PSMB5 and other proteasome encoding genes is too low to explain the development of resistance in most of the affected patients. Thus, additional genetic and epigenetic alterations need to be explored., Experimental Design: We performed DNA methylation profiling by Deep Bisulfite Sequencing in PSMB5, PSMC2, PSMC5, PSMC6, PSMD1, and PSMD5, a subset of proteasome subunits that have hitherto been associated with PI resistance, recruited from our own previous research, the literature, or a meta-analysis on the frequency of somatic mutations. Methylation was followed up on gene expression level and by dual-luciferase reporter assay. The KMS11 cell line served as a model to functionally test the impact of demethylating agents., Results: We identified PSMD5 promoter hypermethylation and subsequent epigenetic gene silencing in 24% of PI refractory patients. Hypermethylation correlated with decreased expression and the regulatory impact of this region was functionally confirmed. In contrast, patients with newly diagnosed multiple myeloma, along with peripheral blood mononuclear cells and CD138+ plasma cells from healthy donors, generally show unmethylated profiles., Conclusions: Under the selective pressure of PI treatment, multiple myeloma cells acquire methylation of the PSMD5 promoter silencing the PSMD5 gene expression. PSMD5 acts as a key orchestrator of proteasome assembly and its downregulation was described to increase the cell's proteolytic capacity. PSMD5 hypermethylation, therefore, represents a novel mechanism of PI tolerance in multiple myeloma., (©2022 American Association for Cancer Research.)

Next-generation sequencing (NGS) has greatly improved our ability to detect the genomic aberrations occurring in multiple myeloma (MM); however, its transfer to routine clinical labs and its validation in clinical trials remains to be established. We designed a capture-based NGS targeted panel to identify, in a single assay, known genetic alterations for the prognostic stratification of MM. The NGS panel was designed for the simultaneous study of single nucleotide and copy number variations, insertions and deletions, chromosomal translocations and V(D)J rearrangements. The panel was validated using a cohort of 149 MM patients enrolled in the GEM2012MENOS65 clinical trial. The results showed great global accuracy, with positive and negative predictive values close to 90% when compared with available data from fluorescence in situ hybridization and whole-exome sequencing. While the treatments used in the clinical trial showed high efficacy, patients defined as high-risk by the panel had shorter progression-free survival ( p = 0.0015). As expected, the mutational status of TP53 was significant in predicting patient outcomes ( p = 0.021). The NGS panel also efficiently detected clonal IGH rearrangements in 81% of patients. In conclusion, molecular karyotyping using a targeted NGS panel can identify relevant prognostic chromosomal abnormalities and translocations for the clinical management of MM patients.

Cereblon is the direct binding target of the immunomodulatory drugs (IMiDs) that are commonly used to treat multiple myeloma (MM), the second most frequent hematologic malignancy. Patients respond well to initial treatment with IMiDs, but virtually all patients develop drug resistance over time, and the underlying mechanisms are poorly understood. We identified an as yet undescribed DNA hypermethylation in an active intronic CRBN enhancer. Differential hypermethylation in this region was found to be increased in healthy plasma cells, but was more pronounced in IMiD-refractory MM. Methylation significantly correlated with decreased CRBN expression levels. DNA methyltransferase inhibitor (DNTMi) in vitro experiments induced CRBN enhancer demethylation, and sensitizing effects on lenalidomide treatment were observed in 2 MM cell lines. Thus, we provide first evidence that aberrant CRBN DNA methylation is a novel mechanism of IMiD resistance in MM and may predict IMiD response prior to treatment., (© 2021 by The American Society of Hematology.)

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.

Mitochondria are involved in the development and acquisition of a malignant phenotype in hematological cancers. Recently, their role in the pathogenesis of multiple myeloma (MM) has been suggested to be therapeutically explored. MYC is a master regulator of b-cell malignancies such as multiple myeloma, and its activation is known to deregulate mitochondrial function. We investigated the impact of mitochondrial activity on the distinct entities of the disease and tested the efficacy of the mitochondrial inhibitor, tigecycline, to overcome MM proliferation. COXII expression, COX activity, mitochondrial mass, and mitochondrial membrane potential demonstrated a progressive increase of mitochondrial features as the disease progresses. In vitro and in vivo therapeutic targeting using the mitochondrial inhibitor tigecycline showed promising efficacy and cytotoxicity in monotherapy and combination with the MM frontline treatment bortezomib. Overall, our findings demonstrate how mitochondrial activity emerges in MM transformation and disease progression and the efficacy of therapies targeting these novel vulnerabilities.

BCR-ABL1-like B-cell precursor acute lymphoblastic leukemia (BCP-ALL) remains poorly characterized in adults. We sought to establish the frequency and outcome of adolescent and adult BCR-ABL1-like ALL using a novel RNA-Seq signature in a series of patients with BCP-ALL. To this end, we developed and tested an RNA-Seq custom panel of 42 genes related to a BCR-ABL1-like signature in a cohort of 100 patients with BCP-ALL and treated with risk-adapted ALL trials. Mutations related to BCR-ABL1-like ALL were studied in a panel of 33 genes by next-generation sequencing (NGS). Also, CRLF2 overexpression and IKZF1/CDKN2A/B deletions were analyzed. Twenty out of 79 patients (12-84 years) were classified as BCR-ABL1-like (25%) based on heatmap clustering, with significant overexpression of ENAM, IGJ, and CRLF2 (P ≤ 0.001). The BCR-ABL1-like subgroup accounted for 29% of 15-60-year-old patients, with the following molecular characteristics: CRLF2 overexpression (75% of cases), IKZF1 deletions (64%), CDKN2A/B deletions (57%), and JAK2 mutations (57%). Among patients with postinduction negative minimal residual disease, those with the BCR-ABL1-like ALL signature had a higher rate of relapse and lower complete response duration than non-BCR-ABL1-like patients (P = 0.007). Thus, we have identified a new molecular signature of BCR-ABL1-like ALL that correlates with adverse prognosis in adult patients with ALL.

Progressive multifocal leukoencephalopathy rarely occurs in patients with multiple myeloma. Intracranial central nervous system invasion is also an uncommon event in multiple myeloma, occurring in less than 1% of cases. We describe herein an exceptional case of coexisting progressive multifocal leukoencephalopathy and intraparenchymal central nervous system myeloma infiltration. A 73-year-old woman with relapsed multiple myeloma was treated with 15 cycles of lenalidomide and dexamethasone, but therapy had to be stopped because of a hip fracture after a fall. During hospitalization, the patient developed progressive multifocal leukoencephalopathy caused by John Cunningham virus, and a prominent intra-parenchymal CD138-positive infiltrate was detected. VDJ rearrangements of the immunoglobulin heavy chain gene and the mutational profile of plasma cells in bone marrow at the time of diagnosis and in brain biopsy after progression were analyzed by next generation sequencing, showing genetic differences between medullary and extramedullary myeloma cells. The role of long-term treatment with lenalidomide and dexamethasone in the development progressive multifocal leukoencephalopathy or intraparenchymal central nervous system myeloma infiltration remains unknown. However, our results suggest that both events may have arisen as a consequence of treatment-related immunosuppression. Thus, an appropriate clinical approach compatible with the simultaneous treatment of progressive multifocal leukoencephalopathy and multiple myeloma should be developed.

A high proportion of patients with acute myeloid leukemia who achieve minimal residual disease negative status ultimately relapse because a fraction of pathological clones remains undetected by standard methods. We designed and validated a high-throughput sequencing method for minimal residual disease assessment of cell clonotypes with mutations of NPM1 , IDH1/2 and/or FLT3 -single nucleotide variants. For clinical validation, 106 follow-up samples from 63 patients in complete remission were studied by sequencing, evaluating the level of mutations detected at diagnosis. The predictive value of minimal residual disease status by sequencing, multiparameter flow cytometry, or quantitative polymerase chain reaction analysis was determined by survival analysis. The sequencing method achieved a sensitivity of 10 -4 for single nucleotide variants and 10 -5 for insertions/deletions and could be used in acute myeloid leukemia patients who carry any mutation (86% in our diagnostic data set). Sequencing-determined minimal residual disease positive status was associated with lower disease-free survival (hazard ratio 3.4, P =0.005) and lower overall survival (hazard ratio 4.2, P <0.001). Multivariate analysis showed that minimal residual disease positive status determined by sequencing was an independent factor associated with risk of death (hazard ratio 4.54, P =0.005) and the only independent factor conferring risk of relapse (hazard ratio 3.76, P =0.012). This sequencing-based method simplifies and standardizes minimal residual disease evaluation, with high applicability in acute myeloid leukemia. It is also an improvement upon flow cytometry- and quantitative polymerase chain reaction-based prediction of outcomes of patients with acute myeloid leukemia and could be incorporated in clinical settings and clinical trials., (Copyright © 2019 Ferrata Storti Foundation.)