Assessment of Clonotypic Rearrangements and Minimal Residual Disease in Lymphoid Malignancies: A Large Cancer Center Experience Using clonoSEQ

Delphi Survey on Measurable Residual Disease in Multiple Myeloma: Prevailing Practices and the Way Forward in India

BACKGROUND

Measurable residual disease (MRD) is becoming a cornerstone in the multiple myeloma (MM) management; however, its implementation in India faces several challenges. This Delphi survey aimed to gather expert consensus on the current practices, and barriers in MRD monitoring in MM in India.

METHODS

A 3-round Delphi process (2 e-surveys and 1 in-person meeting) was conducted with hematologists, pathologists, and oncologists managing MM in India. Consensus (≥ 75% agreement) led to recommendations for standardized MRD practices.

RESULTS

Twenty-five experts participated, agreeing on key protocols: processing first-pull bone marrow aspirates within 24 hours, using a single tube with at least a 10-color panel, acquiring at least 3 million events for 10⁻⁵ sensitivity under proper environmental control, and by adequately trained staff. At least 4 monoclonal antibodies for gating of plasma cells and at least 3 parameters among mast cells, myeloid precursors, hematogones, normal plasma cells, should be used to assess hemodilution. Guidance on modulation of treatment decisions, including maintenance therapy based on MRD status remains inconclusive. Though, there is an agreement that MRD negativity in MM improves survival and lowers relapse risk but currently it does not influence maintenance therapy decisions. MRD testing was advised at postinduction, pre/post-transplant, and annually during maintenance. Challenges identified included protocol variability, interpretation issues, and lack of an external quality assessment program. Experts emphasized the need for advanced flow cytometry training.

CONCLUSIONS

The findings of this study will guide clinical adoption and future research, particularly for high-risk populations and novel therapies.

Nanotechnology Advances in the Detection and Treatment of Lymphoid Malignancies

Lymphoid malignancies are complex diseases with distinct biological behaviors, clinical presentations, and treatment responses. Ongoing research and advancements in biotechnology enhance the understanding and management of these malignancies, moving towards more personalized approaches for diagnosis and treatment. Nanotechnology has emerged as a promising tool to improve some limitations of conventional diagnostics as well as treatment strategies for lymphoid malignancies. Nanoparticles (NPs) offer unique advantages such as enhanced multimodal detection, drug delivery, and targeted therapy capabilities, with the potential to improve precision medicine and patient outcomes. Here, we comprehensively examine the current landscape of nanoconstructs applied in the management of lymphoid disease. Through a comprehensive analysis of preclinical studies, we highlight the translational potential of NPs in revolutionizing the field of hematological malignancies, with a specific focus on lymphoid neoplasms.

Minimal residual disease detection in lymphoma: methods, procedures and clinical significance

Lymphoma is a highly heterogeneous lymphohematopoietic tumor. As our understanding of the biological and pathological characteristics of lymphoma improves, we are identifying an increasing number of lymphoma subtypes. Genotyping has enhanced our ability to diagnose, treat, and monitor the prognosis of lymphoma. Despite significant improvements in treatment effectiveness, traditional methods for assessing disease response and monitoring prognosis are imperfect, and there is no significant improvement in overall remission rates for lymphoma patients. Minimal Residual Disease (MRD) is often indicative of refractory disease or early relapse. For lymphoma patients, personalized MRD monitoring techniques offer an efficient means to estimate disease remission levels, predict early relapse risk, and assess the effectiveness of new drug regimens. In this review, we delve into the MRD procedures in lymphoma, including sample selection and requirements, detection methods and their limitations and advantages, result interpretation. Besides, we also introduce the clinical applications of MRD detection in lymphoma.

Clonotypic VDJ Rearrangements in Mixed Phenotype Acute Leukemia can be Successfully Utilized to Track Minimal Residual Disease

INTRODUCTION

Multiplex polymerase chain reaction (PCR) and next-generation sequencing (NGS) can both be used to identify a neoplastic clonotype by targeting CDR3 and assessing rearrangements in IgH, IgK, IgL, TCR-β, and TCR-gamma loci. The clonotypic sequence can be robustly used to track minimal residual disease (MRD). The ability to track MRD by NGS in mixed phenotype acute leukemia (MPAL) is unknown and warrants investigation.

METHODS

Institutional Review Board (IRB) approval was obtained. Central Moffitt Cancer Center (MCC) database was searched to locate any patients with MPAL from over 600,000 entries. Patient charts were manually curated to identify those with clonoSEQ data, and clinical data was procured from the electronic medical record (EMR).

RESULTS

Twenty-nine patients with MPAL were identified. Only 2 patients with clonoSEQ testing were found. Both demonstrated a B/myeloid phenotype, and both were bilineal. NGS (clonoSEQ) identified 4 dominant (IGH) (patient A; 8/2019) and 2 dominant sequences (patient B; 10/2019), respectively. In both patients, clonoSEQ testing successfully tracked minimal residual disease and mirrored clinical disease burden.

CONCLUSIONS

This report is the first to confirm the utility of NGS-based MRD tracking in patients with MPAL and shows increased sensitivity of NGS over MRD flow cytometry.

Integrated antibody and cellular immunity monitoring are required for assessment of the long term protection that will be essential for effective next generation vaccine development

The COVID pandemic exposed the critical role T cells play in initial immunity, the establishment and maintenance of long term protection, and of durable responsiveness against novel viral variants. A growing body of evidence indicates that adding measures of cellular immunity will fill an important knowledge gap in vaccine clinical trials, likely leading to improvements in the effectiveness of the next generation vaccines against current and emerging variants. In depth cellular immune monitoring in Phase II trials, particularly for high risk populations such as the elderly or immune compromised, should result in better understanding of the dynamics and requirements for establishing effective long term protection. Such analyses can result in cellular immunity correlates that can then be deployed in Phase III studies using appropriate, scalable technologies. Measures of cellular immunity are less established than antibodies as correlates of clinical immunity, and some misconceptions persist about cellular immune monitoring usefulness, cost, complexity, feasibility, and scalability. We outline the currently available cellular immunity assays, review their readiness for use in clinical trials, their logistical requirements, and the type of information each assay generates. The objective is to provide a reliable source of information that could be leveraged to develop a rational approach for comprehensive immune monitoring during vaccine development.

Minimal residual disease detection by next-generation sequencing of different immunoglobulin gene rearrangements in pediatric B-ALL

While the prognostic role of immunoglobulin heavy chain locus (IGH) rearrangement in minimal residual disease (MRD) in pediatric B-acute lymphoblastic leukemia (B-ALL) has been reported, the contribution of light chain loci (IGK/IGL) remains elusive. This study is to evaluate the prognosis of IGH and IGK/IGL rearrangement-based MRD detected by next-generation sequencing in B-ALL at the end of induction (EOI) and end of consolidation (EOC). IGK/IGL rearrangements identify 5.5% of patients without trackable IGH clones. Concordance rates for IGH and IGK/IGL are 79.9% (cutoff 0.01%) at EOI and 81.0% (cutoff 0.0001%) at EOC, respectively. Patients with NGS-MRD < 0.01% at EOI or <0.0001% at EOC present excellent outcome, with 3-year event-free survival rates higher than 95%. IGH-MRD is prognostic at EOI/EOC, while IGK-MRD at EOI/EOC and IGL-MRD at EOI are not. At EOI, NGS identifies 26.2% of higher risk patients whose MRD < 0.01% by flow cytometry. However, analyzing IGK/IGL along with IGH fails to identify additional higher risk patients both at EOI and at EOC. In conclusion, IGH is crucial for MRD monitoring while IGK and IGL have relatively limited value.

Molecular techniques drive cutting edge advancements in management of cutaneous T cell lymphoma

Cutaneous 5T cell lymphoma (CTCL), characterized by malignant T cells infiltrating the skin with potential for dissemination, remains a challenging disease to diagnose and treat due to disease heterogeneity, treatment resistance, and lack of effective and standardized diagnostic and prognostic clinical tools. Currently, diagnosis of CTCL practically relies on clinical presentation, histopathology, and immunohistochemistry. These methods are collectively fraught with limitations in sensitivity and specificity. Fortunately, recent advances in flow cytometry, polymerase chain reaction, high throughput sequencing, and other molecular techniques have shown promise in improving diagnosis and treatment of CTCL. Examples of these advances include T cell receptor clonotyping via sequencing to detect CTCL earlier in the disease course and single-cell RNA sequencing to identify gene expression patterns that commonly drive CTCL pathogenesis. Experience with these techniques has afforded novel insights which may translate into enhanced diagnostic and therapeutic approaches for CTCL.

Nanopore sequencing of clonal IGH rearrangements in cell-free DNA as a biomarker for acute lymphoblastic leukemia

Background

Acute Lymphoblastic Leukemia (ALL) is the most common pediatric cancer, and patients with relapsed ALL have a poor prognosis. Detection of ALL blasts remaining at the end of treatment, or minimal residual disease (MRD), and spread of ALL into the central nervous system (CNS) have prognostic importance in ALL. Current methods to detect MRD and CNS disease in ALL rely on the presence of ALL blasts in patient samples. Cell-free DNA, or small fragments of DNA released by cancer cells into patient biofluids, has emerged as a robust and sensitive biomarker to assess cancer burden, although cfDNA analysis has not previously been applied to ALL.

Methods

We present a simple and rapid workflow based on NanoporeMinION sequencing of PCR amplified B cell-specific rearrangement of the (IGH) locus in cfDNA from B-ALL patient samples. A cohort of 5 pediatric B-ALL patient samples was chosen for the study based on the MRD and CNS disease status.

Results

Quantitation of IGH-variable sequences in cfDNA allowed us to detect clonal heterogeneity and track the response of individual B-ALL clones throughout treatment. cfDNA was detected in patient biofluids with clinical diagnoses of MRD and CNS disease, and leukemic clones could be detected even when diagnostic cell-count thresholds for MRD were not met. These data suggest that cfDNA assays may be useful in detecting the presence of ALL in the patient, even when blasts are not physically present in the biofluid sample.

Conclusions

The Nanopore IGH detection workflow to monitor cell-free DNA is a simple, rapid, and inexpensive assay that may ultimately serve as a valuable complement to traditional clinical diagnostic approaches for ALL.

Novel Approaches in Molecular Characterization of Classical Hodgkin Lymphoma

Simple Summary

The unique tumor composition of classical Hodgkin lymphoma (cHL), with only a small fraction of malignant Hodgkin and Reed–Sternberg cells within the tumor tissue, has created many challenges to characterize the genetic alterations that drive this lymphoid malignancy. Major advances in sequencing technologies and detailed analysis of circulating tumor DNA in blood samples of patients have provided important contributions to enhance our understanding of the pathogenesis of cHL. In this review, we provide an overview of the recent advances in genotyping the clonal and mutational landscape of cHL. In addition, we discuss different next-generation sequencing applications to characterize tumor tissue and cell-free DNA, which are now available to improve the diagnosis of cHL, and to monitor therapeutic response or disease progression during treatment and follow up of cHL patients.

Abstract

Classical Hodgkin lymphoma (cHL) represents a B-cell lymphoproliferative disease characterized by clonal immunoglobulin gene rearrangements and recurrent genomic aberrations in the Hodgkin Reed–Sternberg cells in a reactive inflammatory background. Several methods are available for the molecular analysis of cHL on both tissue and cell-free DNA isolated from blood, which can provide detailed information regarding the clonal composition and genetic alterations that drive lymphoma pathogenesis. Clonality testing involving the detection of immunoglobulin and T cell receptor gene rearrangements, together with mutation analysis, represent valuable tools for cHL diagnostics, especially for patients with an atypical histological or clinical presentation reminiscent of a reactive lesion or another lymphoma subtype. In addition, clonality assessment may establish the clonal relationship of composite or subsequent lymphoma presentations within one patient. During the last few decades, more insight has been obtained on the molecular mechanisms that drive cHL development, including recurrently affected signaling pathways (e.g., NF-κB and JAK/STAT) and immune evasion. We provide an overview of the different approaches to characterize the molecular composition of cHL, and the implementation of these next-generation sequencing-based techniques in research and diagnostic settings.

MRD in ALL: Optimization and Innovations

PURPOSE OF REVIEW

Measurable residual disease (MRD) is an important monitoring parameter that can help predict survival outcomes in acute lymphoblastic leukemia (ALL). Identifying patients with MRD has the potential to decrease the risk of relapse with the initiation of early salvage therapy and to help guide decision making regarding allogeneic hematopoietic cell transplantation. In this review, we discuss MRD in ALL, focusing on advantages and limitations between MRD testing techniques and how to monitor MRD in specific patient populations.

RECENT FINDINGS

MRD has traditionally been measured through bone marrow samples, but more data for evaluation of MRD via peripheral blood is emerging. Current and developmental testing strategies for MRD include multiparametric flow cytometry (MFC), next-generation sequencing (NGS), quantitative polymerase chain reaction (qPCR), and ClonoSeq. Novel therapies are incorporating MRD as an outcome measure to demonstrate efficacy, including blinatumomab, inotuzumab ozogamicin, and chimeric antigen receptor T (CAR-T) cell therapy. Understanding how to incorporate MRD testing into the management of ALL could improve patient outcomes and predict efficacy of new therapy options.