Minimal residual disease response-adapted therapy in newly diagnosed multiple myeloma (MASTER): final report of the multicentre, single-arm, phase 2 trial

Opportunities and challenges for MRD assessment in the clinical management of multiple myeloma

Measurable residual disease (MRD) assessment is, from the methodological point of view, ready for prime time in multiple myeloma (MM). Abundant evidence underscores the value of MRD status determined using highly sensitive next-generation flow cytometry and next-generation sequencing tests in evaluating response to treatment and, therefore, prognosis in patients with this disease. MRD response assessment and monitoring might present a range of opportunities for individualized patient management. Moreover, the considerable amounts of high-quality and standardized MRD data generated in clinical trials have led to the acceptance of MRD negativity as an early end point for accelerated regulatory approval of treatments for MM. The data leave no doubt that the efficacy of new regimens in inducing deeper and durable MRD-negative responses is connected with prolonged survival. Yet, several evidential, technical and practical challenges continue to limit the implementation of MRD-guided treatment strategies in routine practice, and the use of MRD as a surrogate end point remains controversial to some. In this Review, we draw on past and present research to propose opportunities for overcoming some of these challenges, and to accelerate the use of MRD assessment for improved clinical management of patients with MM.

Are we maintaining minimal residual disease in myeloma?

Minimal residual disease (MRD) has emerged as an important prognostic maker in patients with multiple myeloma at different stages of their treatment. Moreover, it is being increasingly incorporated as an endpoint in various clinical trials. Since maintenance therapy is an integral part of myeloma treatment, especially in the upfront setting post autologous transplantation, it is imperative to understand the role of MRD testing in the maintenance stetting. This review aims to examine the utility and dynamics of MRD testing in order to elucidate its prognostic role and possible incorporation in clinical decision making processes.

Minimal Residual Disease Testing Infrastructure in Multiple Myeloma: Guidance for Clinical Trial and Routine Practice Use in Canada

Measurable/minimal residual disease (MRD) is 1 of the most powerful prognostic factors for progression-free survival and overall survival in multiple myeloma (MM) and may guide therapeutic approaches. Here, we provide an overview of the current state of MRD testing in MM in Canada, highlighting its current use, approaches, and barriers. Furthermore, we discuss the available MRD assays and address questions on their appropriateness for routine practice and clinical trials. We also provide insights into timepoints for MRD testing and the relevance of achieving durable MRD negativity. The consensus recommendations herein were agreed upon by Canadian hematologists practicing at academic cancer centers and community cancer centers, clinical trial investigators, laboratory personnel, MM patients, and took into consideration the Canadian therapeutic landscape and the impact of anticipated regulatory approvals.

Prognostic Value of Post-Transplant MRD Negativity in Standard Versus High- and Ultra-High-Risk Multiple Myeloma Patients

Background: Cytogenetic abnormalities and the persistence of minimal residual disease (MRD) following autologous stem cell transplantation (ASCT) are two established prognostically unfavorable biomarkers in multiple myeloma (MM). Previous studies have shown that post-transplant MRD status is a powerful predictor of progression-free survival (PFS) and overall survival (OS). However, the impact of MRD remains poorly characterized in MM patients with high- or ultra-high-risk cytogenetics. Objectives: This study investigated the prognostic value of post-transplant MRD in standard- versus high- and ultra-high-risk MM. To this aim, we performed a retrospective analysis of 137 MM patients who underwent high-dose chemotherapy (HDCT) and ASCT at our institution between January 2019 and December 2021. Cytogenetics were assessed by fluorescence in situ hybridization. High-risk genomic alterations included del(17p), t(4;14), t(14;16), t(14;20), gain(1q), and TP53 mutations, with two or more alterations defining the ultra-high-risk category. MRD was assessed in bone marrow aspirates post-ASCT using flow cytometry. Results: Eighty-two (60%) patients were categorized as being at standard risk, forty (29%) as high risk, and fifteen (11%) as ultra-high risk. Median follow-up was 47 months. MRD negativity was achieved in 76 (55%) patients. At 48 months, the overall PFS rate was 61% (72%, 50%, and 32% for the standard-, high-, and ultra-high-risk subgroups, respectively; p = 0.0004), while the OS rate was 85% (89%, 79%, and 80% in standard-, high-, and ultra-high-risk MM patients, respectively; p = 0.1494). Within the standard-risk subgroup, longer PFS was observed for patients achieving MRD negativity (p = 0.0172). High- and ultra-high-risk patients showed no significant differences in PFS when stratified by MRD status, possibly due to prompt progression to MRD positivity. Conclusions: Our results suggest that high- and ultra-high-risk MM patients might benefit from closer response monitoring, including dynamic MRD assessment. Further, high- and ultra-high-risk patients might require a more intensive peri-transplant treatment.

Impact of quadruplet induction therapy on stem cell mobilization yields in newly diagnosed multiple myeloma

Daratumumab-containing quadruplet induction regimens have recently become the standard of care for patients with newly diagnosed multiple myeloma who are candidates for autologous hematopoietic stem cell transplantation. Daratumumab is a known immunosuppressant, and previous studies have shown that it may impair stem cell mobilization yields. We report a retrospective study of 104 newly diagnosed multiple myeloma patients comparing mobilization yields between those who received quadruplet daratumumab-containing induction and those who received traditional three-drug induction. Our results demonstrated that there were no statistically significant differences in achieving the patient-specific minimally required CD34+ cell yield after the first mobilization attempt between patients in the daratumumab-containing arm and those in the non-daratumumab-containing arm (P = 0.28).However, patients who received the quadruplet induction regimen with daratumumab experienced a statistically significant longer duration of apheresis collection (median of 2 days in the daratumumab-containing arm vs. 1 day in the non-daratumumab-containing arm, P = 0.011) than those who received traditional three-drug induction.Our findings reinforce the importance of incorporating both granulocyte-colony stimulating factors and plerixafor upfront into mobilization practices. Furthermore, the findings of this study may have implications for the judicious use of apheresis machines and further inform the optimal delivery of daratumumab-containing induction therapies for newly diagnosed multiple myeloma.

Establishing measurable residual disease trajectories for patients on treatment for newly diagnosed multiple myeloma as benchmark for deployment of T-cell redirection therapy

Autologous stem cell transplantation (ASCT) has been the prime consolidative strategy to increase the depth and duration of response in newly diagnosed multiple myeloma (NDMM), albeit with short- and long-term toxicities. Minimal residual disease (MRD) is an important early response endpoint correlating with clinically meaningful outcomes and may be used to isolate the effect of ASCT. We report the impact of ASCT on MRD burden and generate a benchmark for evaluation of novel treatments as consolidation. We collected MRD by next generation sequencing (NGS; clonoSEQ®) post induction and post-ASCT in consecutive patients (N = 330, quadruplet, N = 279; triplet, N = 51). For patients receiving quadruplets, MRD < 10-5 post-induction was 29% (MRD < 10-6 15%) increasing to 59% post-ASCT (MRD < 10-6 45%). Among patients with MRD > 10-5 post-induction, ASCT lowered the MRD burden>1 log10 for 69% patients. The use of quadruplet induction (vs. triplet) did not reduce the effect of ASCT on MRD burden. Reduction in MRD burden with ASCT was most pronounced in patients with high-risk chromosome abnormalities.This dataset provides granular data to delineate the impact of ASCT on MRD as legacy consolidative strategy in NDMM and provides an important benchmark for evaluation of efficacy of TCRT as experimental consolidative strategy.

Clinical benefit loss in myeloma patients declining autologous stem cell transplantation: a real-world study

Autologous hematopoietic stem cell transplantation (ASCT) is a recommended treatment for multiple myeloma (MM). Currently, with multiple treatment alternatives, patients' prognosis has improved significantly compared to the pre-proteasome inhibitor period. However, this has raised deliberations on the value and timing of ASCT. Compared with Western countries, the proportion of Chinese patients undergoing ASCT is relatively low. Nevertheless, this situation allows us to observe the treatment outcomes of transplant-eligible (TE) patients who haven't received ASCT and explore the role of ASCT in patients with distinct clinicopathological features. This real-world analysis encompassed 1059 newly diagnosed MM patients from 2012 to 2022, among whom 480 were TE. These patients were categorized into the TE-ASCT group (158 received ASCT) and the TE-no-ASCT group (322 did not receive ASCT). Disease progression and treatment response are evaluated based on the definition of IMWG. We found that the progression-free survival (PFS) was significantly prolonged in TE-ASCT group compared to TE-no-ASCT group, but there was no significant difference in overall survival (OS). Further exploratory analyses revealed that ASCT conspicuously augmented the PFS of patients aged ≤ 60 years, featuring ISS stage II/III, 1q gain/amplification, and positive minimal residual disease (MRD). Nevertheless, for patients aged > 60 years, presenting with ISS stage I, high-risk cytogenetics, renal insufficiency, and negative MRD, ASCT did not confer PFS benefits. Our investigation furnishes evidence of the clinical superiority of ASCT for MM patients with disparate clinicopathological characteristics in the contemporary treatment era, laying a groundwork for individualized ASCT selection.

Consensus Guidelines and Recommendations for The CD38 Monoclonal Antibody-based Quadruplet Therapy and Management in Clinical Practice for Newly Diagnosed Multiple Myeloma: From the Pan-Pacific Multiple Myeloma Working Group

The therapeutic outcomes of clinical trials for incorporating anti-CD38 monoclonal antibodies (including isatuximab and daratumumab) into the bortezomib/lenalidomide/dexamethasone (VRd) triplet therapy backbone as the first-line treatment for newly diagnosed multiple myeloma (NDMM) have demonstrated significant improved efficacies. From a safety perspective, the addition of anti-CD38 monoclonal antibodies into the triplet therapies did not raise additional safety concerns. Based on the promising results, the National Comprehensive Cancer Network (NCCN) Guidelines Version 1.2025 had updated the quadruplet therapy incorporating anti-CD38 monoclonal antibodies with VRd-based therapies as the primary therapy for both transplantation-eligible and transplantation-ineligible NDMM patients. Thus, a panel of experts in hematology and oncology with extensive experience in the treatment of NDMM was convened in 2024 to develop consensus recommendations based on recent evidence from pivotal clinical trials and real-world practices, providing clear guidance for optimizing treatment strategies in both transplantation-eligible and transplantation-ineligible patients. The main topics identified for discussion and recommendation were: (i) the benefits and indications for quadruplet therapy for NDMM; (ii) the optimization of quadruplet therapy strategies; (iii) the management and monitoring of potential adverse events for quadruplet therapy, and (iv) the impact of quadruplet regimens on tandem stem cell transplantation and maintenance treatment. Recommendations were then presented to the entire panel for further discussion and amendment before voting. This manuscript presents the recommendations developed, including findings from the expert panel discussions, consensus recommendations and a summary of evidence supporting each recommendation.

Risk-adapted treatment for multiple myeloma: assessing the current potential and a roadmap for the future

Over the past two decades, new agents for multiple myeloma (MM) have significantly improved patient outcomes, particularly for those with standard-risk disease, who now have a median overall survival of over a decade. However, this benefit is less pronounced in high-risk and ultra-high-risk MM, where median survival ranges from 3 to 5 years. The definition of HRMM continues to evolve and is driven by the genomic features, disease burden, and medical comorbidities. Various risk stratification tools are available to gauge the risk status of the disease. Recently, a slew of single-arm phase 2 trials for high-risk MM have been reported with a general theme of intensification of various phases of treatment. Additionally, minimal residual disease testing in treatment escalation/de-escalation is being actively investigated. This review summarizes the existing evidence for risk-adapted treatment in patients with MM.

Carfilzomib prescribing patterns and outcomes for relapsed or refractory multiple myeloma: a real-world analysis

Despite the widespread use of carfilzomib (K) in relapsed/refractory multiple myeloma (RRMM), there is no consensus on optimal K dose in milligrams per square meter (mg/m2) or dosing schedule. We assessed three modern K prescribing patterns in RRMM using a large United States electronic health record-derived database. Our final cohort (n = 486) included 136 patients (28.0%) who received K 56 mg/m2 once weekly (K56-1x), 86 (17.7%) who received 56 mg/m2 twice weekly (K56-2x), and 264 (54.3%) who received 70 mg/m2 once weekly (K70-1x). Between 2016 and 2023, once-weekly dosing became more common: K70-1x proportions changed from 21.1% in 2016 to 50.6% in 2023, K56-1x from 15.8% to 37.0%, and K56-2x from 63.2% to 12.3%. Median progression-free survival was 13.0 months [95% confidence interval (CI) 11.2-20.7] for K56-1x, 13.2 months (95% CI 9.0-28.1 months) for K56-2x, and 10.9 months (95% CI 9.9-15.3 months) for K70-1x; these differences were not statistically significant (log-rank p = 0.46). Rates of heart failure was comparable (<5% in all cohorts). In summary, our findings do not support improved outcomes with twice-weekly carfilzomib in RRMM. K56-1x may provide the best balance of efficacy, safety, and avoidance of time toxicity from frequent infusions.

Daratumumab-based quadruplet versus triplet induction regimens in transplant-eligible newly diagnosed multiple myeloma: a systematic review and meta-analysis

The treatment landscape for transplant-eligible patients with newly diagnosed multiple myeloma (TE-NDMM) has evolved with the introduction of daratumumab-based quadruplet regimens. Adding daratumumab to traditional triplet regimens has demonstrated improved response rates and progression-free survival (PFS). However, the impact on long-term outcomes, particularly overall survival (OS), remains uncertain. This systematic review and meta-analysis aimed to compare the survival outcomes of these quadruplet regimens with triplets. Conducted in adherence to Cochrane Collaboration and PRISMA guidelines and registered on PROSPERO (CRD42024571946), the study involved searching PubMed, Embase, and Cochrane databases, from inception to June 2024. We included randomized clinical trials (RCT) and non-randomized controlled studies (NRCS) that compared daratumumab-based quadruplet regimens to triplets, focusing on OS and PFS, with a minimum follow-up of 18 months. The meta-analysis included 3327 TE-NDMM patients from four studies, comprising three RCT and one NRCS. Daratumumab-based regimens were administered to 1328 (40%) patients. The analysis revealed that daratumumab-based quadruplet regimens significantly improved both OS (pooled HR 0.60; 95% CI 0.48-0.75; P < 0.00001; I² = 0%) and PFS (pooled HR 0.49; 95% CI 0.37-0.65; P < 0.00001; I² = 52%). A per-protocol subgroup analysis comparing D-VRD to VRD further confirmed these benefits, with significant improvements in both OS (pooled HR 0.68; 95% CI 0.48-0.97; P = 0.03; I² = 0%) and PFS (pooled HR 0.41; 95% CI 0.31-0.54; P < 0.00001; I² = 0%). This meta-analysis consolidates evidence that daratumumab-based quadruplet regimens significantly improve OS, compared to triplet regimens for TE-NDMM patients.

Expert Perspectives on Current Challenges and Emerging Approaches for Multiple Myeloma: Narrative Review of an Inaugural Bridging the Gaps in Leukemia, Lymphoma, and Multiple Myeloma

PURPOSE

The management of multiple myeloma (MM) is becoming increasingly more complex. The approval of novel treatment approaches provides much-needed opportunities but also raises questions and controversies about how to optimally sequence therapies and select treatments for individual patients.

METHODS AND RESULTS

A panel of experts assembled to discuss current controversies in the care of patients with MM across the disease continuum. Workshop topics included: management of smoldering MM; treatment selection for transplant-eligible and transplant-ineligible patients; risk assessment and the possibility of risk-adapted treatment; use of measurable residual disease (MRD) as a clinical trial end point and to guide treatment decisions; management of early relapse; management of triple class-refractory MM; treatment sequencing; and novel therapies.

CONCLUSION

Many controversies remain regarding the management of patients with MM related to risk assessment, treatment selection and sequencing, and the optimal use of current therapies while balancing efficacy, toxicity, patient considerations, and treatment logistics. Ongoing research efforts are needed to further define the optimal use of current therapies and to develop more efficacious therapies for all patients and for particular subset populations with unmet need.

Outcomes of Standard-Risk Multiple Myeloma Patients Who Undergo Upfront Autologous Hematopoietic Stem Cell Transplantation

Patients with multiple myeloma (MM) without high-risk cytogenetic abnormalities are classified as having standard-risk MM (SRMM), and data focusing on their outcomes after autologous hematopoietic stem cell transplantation (autoHCT) are limited. We sought to evaluate survival outcomes for patients with SRMM receiving autoHCT, and to elucidate factors that impact these outcomes. This was a single-center retrospective analysis that included consecutive MM patients who received upfront autoHCT between 2013 and 2021, had available cytogenetic information and had no high-risk chromosomal abnormalities on fluorescence in situ hybridization, defined as t(4;14), t(14;16), del(17p) or 1q21 gain or amplification. A total of 1000 SRMM patients were included, with a median age of 61 years (range 25 to 83), and 61% were male (n = 612). The most common induction regimens were bortezomib/lenalidomide/dexamethasone (VRD; n = 398, 40%) and carfilzomib/lenalidomide/dexamethasone (KRD; n = 212, 21%), and the majority (87%) received single-agent melphalan as conditioning. After induction and before autoHCT, 16% and 57% achieved ≥complete response (CR) and ≥very good partial response (VGPR), respectively. At day 100 post autoHCT, 37% and 77% achieved ≥CR and ≥VGPR, respectively. Sixty-two percent and 89% of patients achieved ≥ CR and ≥VGPR as best response post-transplant. A minimal residual disease (MRD) negative response pre- and post-transplantation was achieved in 43% (401/936) and 64% (199/311) of patients, respectively. After a median follow-up of 42.1 months, the median progression-free survival (PFS) for the entire cohort was 68.3 months (95% CI 60.1 to 72.1), and the median overall survival (OS) was not reached (95% CI 102.3-not reached). The 5-year PFS and OS rates were 55% and 83%, respectively. In multivariable analysis, achieving MRD-negative CR prior to autoHCT (HR 0.65 [95% CI 0.44 to 0.97], P = .033) or as best response (0.52 [0.34 to 0.78], P = .002), and use of post-transplant maintenance (0.69 [0.52 to 0.93], P = .013) and lenalidomide-based combination maintenance (0.68 [0.48 to 0.96], P = .030) were associated with improved PFS, whereas use of an induction regimen other than KRD was associated with worse PFS (1.50 [1.04 to 2.17], P = .031). For OS, post-transplant maintenance (0.48 [0.32 to 0.70], P < .001) was associated with better survival in multivariable analysis, whereas R-ISS stage III, compared with stage I, (2.34 [1.01 to 5.43], P = .047) was associated with worse OS. Patients with SRMM who received upfront autoHCT had a median PFS of >5.5 years, and median OS was not reached. These results highlight the favorable outcomes with upfront autoHCT for patients with SRMM, serving as a benchmark for future therapeutic approaches in this subgroup of MM patients.

Current State of Evidence on Definitions and Management of High-Risk Multiple Myeloma

PURPOSE OF REVIEW

This review aims to address the subgroup of patients with newly diagnosed multiple myeloma (NDMM) who have high-risk multiple myeloma (HRMM) and continue to experience poor outcomes despite recent therapeutic advances. We will explore various clinical, biochemical, imaging, genetic, and dynamic features associated with high-risk status, along with the different risk stratification tools developed to identify HRMM patients.

RECENT FINDINGS

Although numerous parameters for defining HRMM have been proposed, a universally accepted definition remains absent. Studies have shown diverse treatment responses and varying outcomes in HRMM patients, prompting the development of tailored therapeutic approaches. Emerging evidence supports the need for refined definitions and more targeted strategies to improve HRMM management. HRMM patients represent an unmet need in NDMM treatment, and a standardized definition for HRMM is crucial for advancing research and clinical care. This review discusses current and future treatment options, the necessity for a consistent HRMM definition, and the importance of clinical trials focused on this high-risk group to bridge existing treatment gaps.

Evolution of frontline treatment for multiple myeloma: clinical investigation of quadruplets containing carfilzomib and anti-CD38 monoclonal antibodies

Although survival rates for patients with newly diagnosed multiple myeloma (NDMM) have improved over recent decades, multiple myeloma (MM) remains without a cure for most. There is increasing consensus that achievement of deep remissions, especially minimal residual disease negativity (MRD -), in frontline treatment is crucial and translates into improved survival. The standard of care (SOC) for NDMM consists at minimum of a triplet regimen of therapies, with or without an autologous stem cell transplant, or a doublet regimen for certain ineligible, particularly frail patients who may have specific limitations. Recently, anti-CD38 monoclonal antibodies (mAbs), such as daratumumab (Dara) or isatuximab (Isa), have been integrated into frontline SOC regimens. Seeking to further deepen and prolong responses, several clinical trials have commenced investigating the addition of anti-CD38 mAbs to carfilzomib, lenalidomide, and dexamethasone (KRd). These quadruplet regimens (Isa/Dara-KRd) are being evaluated in the context of evolving treatment considerations for the heterogeneous population of patients with NDMM. In clinical trials, the addition of Isa/Dara to KRd achieved high rates of deep responses and MRD - . Favorable outcomes were observed in patients with NDMM independent of age, transplant eligibility, and cytogenetic risk, while these treatments did not result in unexpected or emergent safety risks. The efficacy observed with intensified, yet well-tolerated therapy may offer further development of risk- and response-adapted therapy for individualized patient needs. This review summarizes the clinical outcomes of quadruplet-based therapy with Isa/Dara-KRd in NDMM.

Evolving strategies in the management of transplant-eligible patients with newly diagnosed multiple myeloma

Multiple myeloma treatment has evolved significantly with the introduction of triplet and quadruplet regimens, notably incorporating anti-CD38 antibodies. While autologous stem cell transplantation remains a cornerstone of therapy, its role in the context of increasingly effective upfront treatments is debated. Current guidelines still recommend transplant for all eligible patients, especially those with high-risk features at diagnosis, despite concerns regarding the lack of overall survival benefits and the potential long-term toxicities associated with high-dose melphalan. Delaying transplantation until first relapse has been proposed, but this approach carries the risk of patients becoming ineligible for transplantation due to worsening health or disease progression. Consolidation therapy after transplant is not strongly endorsed in recent guidelines, and studies show mixed results regarding its efficacy. Some data suggests a progression-free survival advantage with post-ASCT consolidation; others found no significant differences in outcomes among various strategies. Nonetheless, tandem transplant may be beneficial for high-risk patients. Maintenance therapy, particularly with lenalidomide, has proven effective, offering substantial progression-free and overall survival benefits. While lenalidomide remains the standard, emerging data indicate that combinations with proteasome inhibitors or anti-CD38 antibodies could enhance outcomes, particularly in high-risk populations. As our understanding of myeloma biology deepens, tailoring treatment approaches based on risk profiles and response depth will be crucial for optimizing patient outcomes.

Treatment of elderly and frail myeloma patients

Multiple myeloma (MM) is an incurable cancer of older adults. Given the aging population, the prevalence of older adults with MM is expected to further increase over the next decade. Challenges in treating older adults result from the heterogeneity of both aging itself and the disease. Over the past two decades, tremendous progress has been made in improving the outcome in this age group with novel therapeutics, including immunomodulatory drugs, proteasome inhibitors, and more recently anti-CD38 monoclonal antibodies, becoming an integral part of initial treatment. Further improvements are expected over the next decade with novel immunotherapy, including T-cell engagers and chimeric antigen receptor therapies. With additional novel treatments, assessment of patient frailty will become increasingly important in balancing the optimal treatment of patients. In this review, we focus on the treatment of elderly and frail older adults with MM. The first part of our review will focus on pertinent investigations, considerations for treatment initiation and initial risk stratification, including frailty assessment prior to treatment initiation. In the second part, we will focus on the overall goals of treatment and therapeutic options for newly diagnosed and those with relapsed/refractory MM, including novel immunotherapy and supportive care. Lastly, we will end this review by highlighting current knowledge gaps and providing suggestions for future directions to further improve outcomes among older adults with MM.

Minimal residual disease in multiple myeloma

Minimal Residual Disease (MRD) in multiple myeloma has emerged as a significant prognostic factor, guiding treatment strategies and enhancing patient outcomes. Despite advancements in therapies such as proteasome inhibitors, immunomodulatory drugs, monoclonal antibodies, CAR-T cell therapy, and bispecific antibodies, complete eradication of malignant plasma cells remains challenging. MRD refers to a small number of residual cancer cells that persist after treatment and require sensitive methods like next-generation flow cytometry (NGF) and next-generation sequencing (NGS) for detection. MRD negativity has been associated with improved progression-free survival (PFS) and overall survival (OS), making it a key marker in clinical trials. The clinical utility of MRD lies in its ability to predict outcomes, with sustained MRD negativity linked to prolonged survival. Furthermore, it will likely help in tailoring treatment approaches, such as therapy escalation for high-risk patients or de-escalation for those achieving MRD negativity. Despite its prognostic value, challenges remain in standardizing MRD testing, ensuring its widespread availability, and addressing variability in results based on different detection methods. Future research aims to refine MRD-guided treatment and explore novel detection techniques, such as liquid biopsies, to improve patient monitoring in multiple myeloma.

How First-Line Therapy is Changing in Transplant-Eligible Multiple Myeloma Patients

Multiple myeloma is a malignant haematological neoplasm characterised by the proliferation of plasma cells in the bone marrow. Each year, over 35,000 new cases are diagnosed in the United States, and nearly 13,000 patients die from the disease.1 The main cause of morbidity is bone disease, characterised by osteolytic lesions, which, unlike other malignancies that metastasise to bone, are not followed by new bone formation.2 Other major clinical manifestations include anaemia, hypercalcemia, renal failure, and an increased risk of infections. Approximately 1-2% of patients present with extramedullary disease (EMD) at the time of diagnosis, while 8% develop EMD later in the course of the disease.3 Although multiple myeloma remains incurable, its treatment continues to evolve rapidly. Approved therapies include immunomodulatory agents (IMiDs, such as thalidomide, lenalidomide, and pomalidomide), proteasome inhibitors (bortezomib, carfilzomib, and ixazomib), and monoclonal antibodies (mAb) targeting CD38 (especially daratumumab and isatuximab) and SLAMF7. New therapeutic avenues include bispecific antibodies and chimeric antigen receptor T-cell (CAR-T) therapy.4-5 The latest ESMO (European Society for Medical Oncology)6 and NCCN (National Comprehensive Cancer Network) guidelines7 have set the standard of care for patients with newly diagnosed multiple myeloma (NDMM) eligible for transplantation, particularly those in good general condition and < 70 years old. This approach is divided into four phases: induction therapy, hematopoietic stem cell collection, and autologous transplant, consolidation, and maintenance. The most significant differences between the guidelines occur during the induction phase, influenced by regulatory approvals in the United States and Europe. This article will focus on the changing landscape of therapies for newly diagnosed multiple myeloma (NDMM) in transplant-eligible.

Novelties on Multiple Myeloma from the Main 2024 Hematology Conferences

Despite the introduction of several therapies in recent years, multiple myeloma (MM) remains a hematologic malignancy difficult to treat due to its extreme inter- and intra-patient heterogeneity. However, at the 2024 major international conferences, very significant data have emerged on new approaches that can improve outcomes even in high-risk or very advanced diseases. Up-front quadruplet combinations, including anti-CD38 monoclonal antibodies, proved to be the best therapy in terms of depth of response and long-term efficacy in both transplant-eligible and not-eligible patients with MRD assessment that could play a key role in determining the duration of therapy, avoiding unnecessary overtreatment. However, quadruplets also fail to overcome the negative prognostic value of high-risk cytogenetics or circulating tumour cells; therefore, in patients with these features, alternative approaches will have to be evaluated. Moreover, considering that not all patients, particularly older and frail ones, will be able to undergo such therapies, it will be necessary to refine the ability to identify the most appropriate therapy for each patient. Bispecific antibodies and CAR-T cells represent the new frontier in the treatment of advanced MM. However, they have shown even more efficacy with less toxicity in early relapses and functional high-risk patients. In the upfront setting, the results obtained with the inclusion of novel immunotherapies are extremely promising. In relapsed/refractory MM patients, agents such as belantamab mafodotin and CELMoDs, in combination with proteasome inhibitors or immunomodulatory agents, may represent another valid option.

Co-Occurrence of Cytogenetic Abnormalities and High-Risk Disease in Newly Diagnosed and Relapsed/Refractory Multiple Myeloma

PURPOSE

Survival for patients with multiple myeloma (MM) has improved but outcomes remain heterogeneous. Consistent diagnostic identification of high-risk disease is desirable to address unmet patient need. The aim was to investigate the consistency of association of co-occurrence of high-risk cytogenetic abnormalities (HRCAs) with prognosis in patients with newly diagnosed MM (NDMM) and relapsed/refractory MM (RRMM), and across a range of treatment modalities.

METHODS

A systematic review of randomized controlled trials of MM that reported testing for HRCA between January 1, 2000, and December 9, 2021, was performed. Groups were contacted and asked to locally perform a novel, federated analysis of their data for single hit (one HRCA) and double hit (≥two HRCAs), using a centrally provided algorithm. Analysis results were centrally collated and meta-analyzed to assess the hazard ratio (HR) for progression-free survival (PFS) and overall survival (OS) for one/≥two HRCAs across patient subgroups using random-effects models.

RESULTS

Twenty-four trials including 13,926 patients were included. The median age of participants was 66.5 years (IQR, 59-72) and 56.5% were male (IQR, 52-60). The HR for PFS was 2.28 (95% CI, 2.05 to 2.54) for patients with ≥two HRCAs and 1.51 (95% CI, 1.38 to 1.65) for patients with one HRCA. The HR for OS was 2.94 (95% CI, 2.49 to 3.47) and 1.69 (95% CI, 1.52 to 1.88) for the two subgroups, respectively. In studies initiated since 2015, the effect abides (≥two HRCA PFS, HR, 2.39 [95% CI, 1.96 to 2.91]; OS, 3.10 [95% CI, 2.10 to 4.60]) both for NDMM and RRMM. Heterogeneity related to transplant eligibility and relapsed/refractory status was as expected.

CONCLUSION

The association of ≥two HRCAs with the poorest outcome in NDMM and RRMM, and across treatment modalities, as demonstrated here for the first time to our knowledge, allows for more focused development of novel approaches to these patients with high unmet need.

MRD-driven phase 2 study of daratumumab, carfilzomib, lenalidomide, and dexamethasone in newly diagnosed multiple myeloma

ABSTRACT

In newly diagnosed multiple myeloma (NDMM), measurable residual disease (MRD) status is prognostically important, but its role in treatment decisions remains unclear. In a phase 2 trial, we assessed daratumumab, carfilzomib, lenalidomide, and dexamethasone (Dara-KRd) induction followed by a next-generation sequencing-based MRD-adapted strategy. The primary outcome was complete response (CR) and stringent CR (≥CR) after induction. Flow cytometry was used to profile T cells. Among 39 patients, 21 (54%) achieved ≥CR after induction (P = .375), with MRD-negative rates of 59% (10-5) and 41% (10-6). Patients who were MRD-negative (n = 24, group A) received lenalidomide maintenance, showing sustained MRD negativity in 14 of 18 (77.8%) for ≥12 cycles. MRD-positive transplant-eligible patients (n = 8, group B) underwent autologous stem cell transplantation, with 62.5% converting to MRD-negative at 10-5 (37.5% at 10-6) posttransplant. MRD-positive, transplant-ineligible patients (n = 4, group C) received KRd consolidation. Best MRD-negative rates improved to 77% (10-5) and 72% (10-6). No new safety concerns were identified for Dara-KRd. With a median follow-up of 30.1 months, 3, 2, and 1 patient(s) in groups A, B, and C, respectively, have progressed or died. We observed that Dara-KRd strongly activated memory T cells, which was associated with an MRD-negative state post induction. Although the primary outcome was not met, Dara-KRd induction in NDMM achieved high ≥CR and MRD-negative rates without new safety concerns. The post induction MRD-adapted strategy deepened responses in MRD-positive patients and maintained durable MRD control in MRD-negative patients. This trial was registered at www.clinicaltrials.gov as #NCT04113018.

Allogeneic chimeric antigen receptors (CARs) as an "off-the-shelf" therapy in multiple myeloma

The success of autologous chimeric antigen receptor (CAR)-T cells has changed the treatment landscape in relapsed and refractory multiple myeloma (MM) resulting in potential movement of CAR-T cells to the frontline treatment setting. However, one of the greatest weaknesses of this therapy is its autologous nature, which makes it time-consuming, labor intensive, and dependent on the patient's T cell fitness. The development of allogeneic CARs is critical to overcome these challenges and provide patients with an off-the-shelf alternative that is readily available. This review will investigate the current landscape and future perspectives of allogeneic CAR research in MM, exploring both pre-clinical research and active clinical trials. More specifically, it will focus on the advantages and disadvantages of various CAR cellular candidates including CAR-T, CAR-NK, and CAR-iNKT cells, among other more novel candidates.

VCd versus VRd in Newly Diagnosed Multiple Myeloma: Matched Real-World Analysis from the Balkan Myeloma Study Group (BMSG)

BACKGROUND

Bortezomib, dexamethasone and cyclophosphamide (VCd) remains a popular regimen, due to its activity and low toxicity, while bortezomib, lenalidomide and dexamethasone (VRd) is widely used in US and Europe; both are combined with anti-CD38 monoclonal antibodies but VCd and VRd have not been compared directly in adequately powered prospective trials.

AIM

We compared the outcomes of 1216 patients treated with VCd (N = 690) or VRd (N = 526) in a real-world setting.

RESULTS

Patients treated with VCd had more often severe renal dysfunction, ISS-3 disease, hypercalcemia, elevated LDH, anemia, thrombocytopenia, poor performance while VRd-treated were older and received less often autologous transplant but more frequently maintenance but the duration of induction was similar. VRd was associated with substantially higher overall response and CR/VGPR rates to induction(P < .001) and improved PFS and OS in univariate analysis, especially among patients with standard risk disease, without renal dysfunction and in the elderly; however, in multivariate analysis there was no significant difference in either PFS or OS. In patients strictly matched 1:1 for major prognostic variables (188 in each group, total N = 376), the superiority of VRd in terms of responses rates and depth of response was confirmed, but without significant PFS or OS difference.

CONCLUSION

VRd is a more active induction regimen than VCd, although use of maintenance with lenalidomide may dilute the PFS or OS benefit. VCd induction remains an option in special circumstances. With the implementation of monoclonal antibodies, VCd backbone can be considered for patients without access to or who do not tolerate VRd.

Global, regional and national epidemiological trends of multiple myeloma from 1990 to 2021: a systematic analysis of the Global Burden of Disease study 2021

Background

Multiple myeloma (MM) is a growing global public health challenge. Known epidemiological data suggest that MM accounts for approximately 10% of all hematologic malignancies and remains the second most common hematologic cancer worldwide. This study utilized data from the 2021 Global Burden of Diseases (GBD) study to evaluate the prevalence, incidence, mortality, disability-adjusted life years (DALYs), and attributable risk factors of MM from 1990 to 2021, and to project future trends for the next 15 years.

Methods

GBD 2021 data were analyzed to assess MM's global burden using four key epidemiological measures: prevalence, incidence, mortality, and DALYs. Estimates are reported per 100,000 population with uncertainty intervals (UI). Temporal trends were assessed through estimated annual percentage change (EAPC) and 95% confidence intervals (CI). All analyses were conducted using R version 4.2.1.

Results

From 1990 to 2021, global MM prevalence, incidence, mortality, and DALYs more than doubled, particularly among males. All Social-Demographic Index (SDI) regions showed increases in ASPR, ASIR, ASMR, and ASDR (all EAPCs >0), with the middle SDI regions exhibiting the most rapid growth. ARIMA model predictions suggest that the MM burden will continue rising over the next 15 years. The proportion of MM cases attributable to high BMI also increased globally, from 6.40% in 1990 to 7.96% in 2021. MM primarily affects older adults, with the highest incidence observed in the 70-74 age group and the highest mortality rate recorded in the same age range.

Conclusion

MM presents an escalating global health challenge. Targeted preventive interventions and improvements in diagnosis, treatment, and care are critical, especially in underdeveloped regions, to address the growing global burden of MM.

Minimal Residual Disease Significance in Multiple Myeloma Patients Treated with Anti-CD38 Monoclonal Antibodies

Minimal residual disease (MRD) evaluation is a recognized endpoint in clinical trials. Both next-generation flow and sequencing could be used as complementary techniques to detect myeloma cells after therapy to measure the depth of response and novel drug efficacy. Anti-CD38 monoclonal antibodies combined with proteasome inhibitors and immunomodulatory drugs have increased the quality of response in myeloma patients, and MRD evaluation is also entering routine clinical practice in many hematological centers. This review analyzes updated results from recent clinical trials utilizing anti-CD38 monoclonal antibodies such as isatuximab and daratumumab in terms of their responses and MRD data. MRD-driven therapy appears promising for the future of MM patients, and emerging minimally invasive techniques to assess MRD are under investigation as novel potential methods to replace or integrate traditional MRD evaluation.

Novel Treatment Options for Multiple Myeloma

Multiple myeloma (MM), the second most common hematologic malignancy in the United States, is characterized by repeated cycles of remission and relapse, with increasing resistance to treatment after each line of therapy. Despite the virtually incurable nature of MM, recent therapeutic breakthroughs have fundamentally reshaped its treatment landscape. This review explores evolving care paradigms, spanning from newly diagnosed MM to relapsed or refractory disease. In the frontline setting, treatment strategies have shifted beyond their traditional emphasis on autologous stem-cell transplant eligibility to a broader categorization of patients on the basis of their suitability for quadruplet therapy. In the relapsed/refractory setting, novel immunotherapies, including chimeric antigen receptor T-cell (CAR-T) therapies and bispecific antibodies, have revolutionized treatment, offering new hope for patients with previously limited options. Precision medicine is playing a growing role in MM treatment, with venetoclax showing significant efficacy in patients with t(11;14) translocation, advancing targeted therapy for this subgroup. On the horizon, investigational CAR-T products and cereblon E3 ligase modulators, such as mezigdomide and iberdomide, may provide faster, more durable responses compared with current therapies. In addition, belantamab mafodotin, an antibody-drug conjugate withdrawn from the US market in 2022, is on the verge of reapproval after positive results from recent randomized trials. While these therapies offer significant potential, challenges remain in managing toxicity, ensuring treatment accessibility, and optimizing sequencing strategies. As the therapeutic arsenal expands, the need for personalized MM treatment plans that balance efficacy with quality of life becomes even more essential.

A Pilot Study of UM171-Expanded Cord Blood Grafts for Tandem Auto/Allogeneic Hematopoietic Cell Transplant in High and Ultra-High-Risk Myeloma Patients

Multiple myeloma (MM) remains associated with a poor outcome, particularly in patients with advanced disease and high-risk (HR) cytogenetics. To date, the only curative treatment is allogeneic (allo) hematopoietic cell transplantation (HCT), but high incidences of graft versus host disease (GVHD), nonrelapse mortality (NRM) and disease progression remain important obstacles. Cord blood (CB) transplantation has been associated with low rates of relapse and chronic (c) GVHD, but its use has declined because of high incidences of infections, severe acute GVHD and high NRM. In other hematologic malignancies, UM171-expanded CB transplants have led to improved outcomes, allowing for the selection of smaller, better HLA-matched units. We aimed to investigate the safety and feasibility of single UM171-expanded single CB unit transplantation in frontline tandem auto/allo HCT for HR/ultra-HR MM patients. Newly diagnosed MM patients ≤ 65 years with an ISS stage II/III and del(17p), t(4;14), t(14;16), t(14;20), del(1p) or +1q, R-ISS 3, ≥ 2 cytogenetic abnormalities, or plasma cell leukemia without a sibling donor and availability of a 5-7/8 matched CB graft with ≥ 0.5 x 105 CD34+/kg and ≥ 1.5 x 107 TNCs/kg were eligible to this phase I/II prospective study (ClinicalTrials.gov NCT03441958). After induction and autologous HCT, patients received a reduced intensity conditioning regimen and were infused with 7-day UM171-expanded CD34+ cells, along with the lymphocytes contained in the CD34-negative fraction. The primary endpoints were feasibility of UM171 expansion, safety, kinetics of engraftment, incidences and maximum grades of acute and cGVHD at 1 and 2 years, assessment of measurable residual disease (MRD) and quality of life (QoL). Between 05/2018 and 11/2021, 20 patients were enrolled. One patient had an unsuccessful CB expansion with UM171, leaving 19 patients with a median age of 56 years. Median CD34+ cell dose infused after expansion was 4.62 x 106/kg (range: 0.79 to 5.76). Median times to achieve absolute neutrophil counts of 0.1 and 0.5 x 109/L were D+6 and D+10.5; median time to reach ≥ 20 x 109/L platelets was D+36. Full donor chimerism was achieved in all cell lineages by D+120 in recipients of reduced intensity conditioning. Cumulative incidences of grade II-IV, grade III-IV acute GVHD and moderate/severe cGVHD at 12 months were 68.4% (95% CI: 46 to 90), 5.3% (95% CI: 0% to 16%), and 10.5% (95% CI: 0% to 25%), respectively. With a median follow-up of 2.9 years (range: 0.46 to 5.3), cumulative incidences of relapse, PFS, OS and NRM at 3 years were 36.8% (95% CI: 14 to 59), 47.4% (95% CI: 29 to 76), 68.4% (95% CI: 50 to 93) and 15.8% (95%CI: 0 to 33), respectively. Median time to complete immunosuppression discontinuation was D+238. No unexpected adverse events were observed. Only one of 7 patients alive at 2 years with negative MRD at transplant has relapsed. Non-relapsing patients had a QoL after transplant similar to the general population. UM171-expanded CB transplant in HR/ultra-HR myeloma patients is feasible and allows the use of single CB units with a low risk of cGVHD. Patients with negative pretransplant MRD might benefit most from a UM171-expanded CB transplant.

Real-World Evidence on Prognostic Value of MRD in Multiple Myeloma Using Flow Cytometry

Minimal residual disease (MRD) is one of the most important prognostic factors in multiple myeloma (MM) and a valid surrogate for progression-free survival (PFS) and overall survival (OS). Recently, MRD negativity was approved as an early clinical endpoint for accelerated drug approval in MM. Nevertheless, there is limited evidence of MRD utility in real-world setting. In this retrospective multicenter study, we report outcomes of 331 newly diagnosed MM patients with MRD evaluation at Day+100 after autologous stem cell transplantation using flow cytometry with a median limit of detection of 0.001%. MRD negativity was reached in 47% of patients and was associated with significantly prolonged median PFS (49.2 months vs. 18.4 months; hazard ratios (HR) = 0.37; p < 0.001) and OS (not reached vs. 74.9 months; HR = 0.50; p = 0.007). Achieving MRD negativity was associated with PFS improvements regardless of age, International Staging System (ISS) stage, lactate dedydrogenase (LDH) level, or cytogenetic risk. Importantly, MRD positive patients benefited from lenalidomide maintenance versus no maintenance (18-months PFS: 81% vs. 46%; HR = 0.24; p = 0.002) while in MRD negative patients such benefit was not observed (p = 0.747). The outcomes of our real-world study recapitulate results from clinical trials including meta-analyses and support the idea that MRD positive patients profit more from lenalidomide maintenance than MRD negative ones.

Optimizing multiple Myeloma clinical trials: research direction, addressing limitations, and strategies for improvement

Despite significant advancements in multiple myeloma (MM) treatment, including novel therapies and combination strategies, the translation of findings from randomized controlled trials (RCTs) into real-world clinical practice has been associated with several challenges. Specifically, the principles and criterion that shape the current design of MM RCTs have left out a sizable portion of patients that would particularly benefit from trial inclusion. In addition, RCTs may use primary outcomes which only partially cover patient-relevant endpoints important for evaluating treatment efficacy and quality of life. In this review, we explore the current MM RCT landscape and suggest possible solutions to improve generalizability of trial results, mitigate logistical pitfalls, and integrate real-world evidence into trials. Together, these strategies are designed to refine MM treatment guidelines and improve outcomes for all patient populations.

Quadruplet regimens for patients with newly diagnosed multiple myeloma: a systematic review and meta-analysis

ABSTRACT

Quadruplet regimens (anti-CD38 monoclonal antibodies [mAbs] with proteasome inhibitor [PI] and immunomodulatory drugs [IMiDs]) are increasingly being investigated in newly diagnosed multiple myeloma (NDMM). The objective of our study was to conduct a systematic review and meta-analysis to measure the efficacy and toxicity of quadruplet regimens used in NDMM. Embase, MEDLINE, Web of Science, Cochrane Library, clinical trial registries, and meeting libraries from inception to 24 January 2024, in addition to American Society of Clinical Oncology conference abstracts 2024, were searched using terms reflecting multiple myeloma and components of the quadruplet regimen. Included studies were randomized controlled trials (RCTs) that compared backbone regimens consisting of a PI and IMiD vs the same regimen plus an anti-CD38 mAb in NDMM. We identified 7 RCTs including 3716 patients. Compared with triplets, quadruplets increase the overall response rate (ORR; relative risk [RR], 1.03; 95% confidence interval [CI], 1.01-1.05) and progression-free survival (PFS; hazard ratio [HR], 0.55; 95% CI, 0.46-0.66). Quadruplets increase the rates of minimal residual disease (MRD) negativity at 10-5 (RR, 1.39; 95% CI, 1.23-1.58) and 10-6 (RR, 1.62; 95% CI, 1.36-1.94). Quadruplets improve overall survival (OS; HR, 0.65; 95% CI, 0.53-0.79). There was a slight increase in the rates of grade 3 to 4 infections (RR, 1.22; 95% CI, 1.07-1.39) noted with quadruplets compared with triplets. Overall, in this meta-analysis, quadruplets were associated with improved efficacy including ORR, MRD negativity, PFS, and OS, with a slight increase in infection rates. Quadruplet regimens represent a new standard of care, particularly in transplant-eligible NDMM.

Transplant in myeloma: who, when, and why?

High-dose melphalan supported by autologous transplantation has been the standard of care for eligible patients with newly diagnosed multiple myeloma for nearly 30 years. Several randomized clinical trials have reaffirmed the strong position of transplant in the era of triplets combining proteasome inhibitors, immunomodulatory drugs, and dexamethasone. Although quadruplets are becoming the standard in transplantation programs, no data are currently available on the need for a transplant with new regimens incorporating anti-CD38 monoclonal antibodies. Outcomes remain heterogeneous, with different response depths and durations depending on the cytogenetics at diagnosis. The improvement of disease prognostication using sensitive and specific tools allows for adapting the strategy to initial and dynamic risks. This review examines which patients need a transplant, when transplantation is preferable, and why.

Multiple myeloma clinical trials exclude patients with the highest-risk disease: a systematic review of trial exclusion criteria

Patients with certain subsets of multiple myeloma continue to have poor outcomes and are in need of novel treatment approaches. Strict eligibility criteria for randomized controlled trials (RCTs) limit access to clinical trials and limit the external validity of trial results for these patients. We systematically reviewed RCTs in newly diagnosed myeloma from 2006 to 2023 to ascertain the prevalence of 12 key exclusion criteria and trends over time. 80 RCTs were included. Exclusion criteria included: age in 43 (51%) trials; projected life expectancy in 20 (24%); performance status in 74 (87%); non-secretory and/or oligosecretory disease in 47 (55%), hepatic function in 64 (79%), renal function in 63 (74%), hematological thresholds in 50 (59%), prior malignancy in 68 (80%), and neuropathy in 50 (59%). For 53 trials which had detailed exclusion criteria available, plasma cell leukemia was excluded in 21 (40%), extramedullary disease in 5 (9%) and CNS disease in 13 (25%). The percentage of studies invoking each of these exclusion criteria did not significantly improve over time on univariate regression analysis, and exclusion criteria relating to neuropathy have worsened. The restrictive eligibility criteria of most myeloma RCTs perpetuate a cycle where limited data exists to treat challenging myeloma subtypes.

Measurable Residual Disease in Hematological Cancers

Minimal residual disease (MRD) is most easily defined as a minimal amount of cancer cells that remain following the treatment of the disease, potentially owing to disease recurrence and the patient's dismal prognosis [...].

T Cell-Redirecting Bispecific Antibodies in Multiple Myeloma: Optimal Dosing Schedule and Duration of Treatment

T cell-redirecting bispecific antibodies (BsAb) induce significant responses in heavily pretreated multiple myeloma. BsAbs are currently administered in a dose-dense manner until disease progression. However, continuous therapy is associated with safety concerns, including a high risk of infections and high costs. In addition, chronic exposure to BsAbs, and thus long-term T-cell stimulation, induces T-cell exhaustion, which may contribute to relapse. There is increasing evidence that the strategy of induction treatment followed by maintenance with longer intervals between BsAb doses, or limited treatment duration with cessation of therapy in patients who achieve deep remission, improves the balance between toxicity and efficacy. Significance: There is increasing evidence that after initial debulking, less-frequent BsAb administration mitigates T-cell exhaustion and minimizes the potential for chronic or cumulative toxicity while maintaining durable clinical responses. In addition, specific patient subsets may experience an extended treatment-free period following fixed-duration treatment. Fixed-duration treatment may, therefore, decrease cumulative toxicities and the burden on patients and healthcare systems.

Biomarker-directed therapy in multiple myeloma

PURPOSE OF REVIEW

Multiple myeloma is currently treated with a one-size-fits-all approach despite significant heterogeneity in patient outcomes and disease molecular constitution. A personalised approach would tailor therapy to unique patient or disease characteristics.

RECENT FINDINGS

Well established prognostic biomarkers such as cytogenetic risk and patient frailty status are being evaluated as potential predictive biomarkers. Specifically, treatment intensity can be augmented in high-risk patients or conversely attenuated in those at lower risk or lower ability to withstand treatment toxicities. Alternatively, targeted therapy can be rationally designed to exploit vulnerable pathways in myeloma cells as identified using predictive biomarkers. The t(11;14) translocation, found in approximately 15-20% of myeloma cases, is a leading biomarker for response to BCL-2 inhibitors such as venetoclax.

SUMMARY

Active research efforts exploring venetoclax combination therapies, as well as new generation BCL-2 inhibitors are underway. Following the development of venetoclax, numerous other cellular pathways are under investigation as candidate predictive biomarkers to rationally inform newer targeted therapies in myeloma.

Dynamics of minimal residual disease and its clinical implications in multiple myeloma: A retrospective real-life analysis

BACKGROUND

Minimal residual disease (MRD) testing is a promising approach to tailor the treatment of multiple myeloma (MM). However, several major concerns remain to be addressed before moving it into daily practice, most of which stem from the dynamic nature of the MRD status. Thus, it is crucial to understand the MRD dynamics and propose its clinical implications.

METHODS

We retrospectively analysed the data of patients with newly diagnosed MM (NDMM) who had flow cytometry-based MRD tests at multiple time points after initiation of therapy. The impact of undetectable MRD (including attainment, duration and loss) on clinical outcomes was analysed.

RESULTS

In a cohort of 220 patients with NDMM, attainment of MRD- offered favourable outcomes (P < 0.0001 for both progression-free survival (PFS) and overall survival (OS)), regardless of baseline risk factors. Notably, MRD- duration ≥12 months was associated with an 83 % (95 % confidence interval (CI), 0.09-0.34; P < 0.0001) or 69 % (95 % CI, 0.13-0.76; P = 0.0098) reduction in risk of progression/death or death, while the longer MRD- was sustained, the better the outcome was. Loss of MRD- led to poor PFS (hazard ratio (HR) 0.01, 95 % CI 0-0.06, P < 0.0001) and OS (HR 0.03, 95 % CI 0-0.24, P = 0.0008). Most patients (70 %) who lost MRD- status carried high-risk cytogenetic abnormalities (HRCAs). While MRD- was temporally inconsistent with conventional therapeutic responses (eg ≥ complete remission or very good partial response), it predicted disease progression or recurrence more robustly than the latter. Last, the predictive value of the MRD status was independent of baseline risk factors (eg high-risk cytogenetic abnormality, International Staging System (ISS) or Revised (R-)ISS staging).

CONCLUSIONS

Longitudinal assessment of MRD during the treatment course and follow-up is required for monitoring disease progression or relapse, to guide treatment decisions. Accordingly, a prospective study is currently ongoing to investigate the feasibility and benefit of the MRD-tailored therapy according to the longitudinal changes of the MRD status.

Liquid biopsy: Comprehensive overview of circulating tumor DNA (Review)

Traditional tumor diagnosis methods rely on tissue biopsy, which can be invasive and unsuitable for long-term monitoring of tumor dynamics. The advent of liquid biopsy has notably improved the overall management of patients with cancer. Liquid biopsy techniques primarily involve detection of circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA). The present review focuses on ctDNA because of its significance in tumor diagnosis, monitoring and treatment. The use of ctDNA-based liquid biopsy offers several advantages, including non-invasive or minimally invasive collection methods, the ability to conduct repeated assessment and comprehensive insights into tumor biology. It serves crucial roles in disease management by facilitating screening of high-risk patients, dynamically monitoring therapeutic responses and diagnosis. Furthermore, ctDNA can be used to demonstrate pseudo-progression, monitor postoperative tumor status and guide adaptive treatment plans. The present study provides a comprehensive review of ctDNA, exploring its origins, metabolism, detection methods, clinical role and the current challenges associated with its application.

Advances in adoptive cellular immunotherapy and therapeutic breakthroughs in multiple myeloma

The basic idea of modulating the immune system to better recognize and fight tumor cells has led to the successful introduction of adoptive cellular immunotherapy (ACT). ACT-based treatment regimens, in which the patient's own immune cells are isolated and subsequently expanded (ex vivo) and reinfused, have also contributed significantly to the development of a personalized treatment strategy. Complementing this, the unprecedented advances in ACTs as chimeric antigen receptor (CAR)-T cell therapies and their derivatives such as CAR-NK, CAR-macrophages, CAR-γδT and CAR-NKT have further maximized the therapeutic outcomes. Herein, we provide a comprehensive overview of the development of ACTs in multiple myeloma (MM) and outline how they have evolved from an experimental form to a mainstay of standard clinical settings. Besides, we provide insights into cytokine-induced killer cell (CIK) therapy, an alternative form of ACT that (as CIK or CAR-CIK) has enormous potential in the clinical spectrum of MM. We also summarize the results of the major preclinical and clinical studies of adoptive cell therapy in MM and address the current challenges (such as cytokine release syndrome (CRS) and neurotoxicity) that limit its complete success in the cancer landscape.

Discontinuation of maintenance therapy in multiple myeloma guided by multimodal measurable residual disease negativity (MRD2STOP)

MRD2STOP is a pragmatic trial evaluating maintenance therapy cessation guided by measurable residual disease (MRD) negativity in multiple myeloma (MM). Eligible patients had previous MRD < 10-5, received ≥1 year of maintenance, and were prospectively confirmed to have undetectable disease by positron emission tomography, bone marrow (BM) flow cytometry (limit of detection [LoD] 10-5), and BM clonoSEQ (LoD 10-6). BM aspirates enriched for CD138+ cells were analyzed by clonoSEQ to achieve MRD 10-7 sensitivity. We evaluated the incidence of disease resurgence and progression-free survival (PFS), stratified by 10-7 status. Forty-seven patients discontinued maintenance after a median of 36 months. Baseline MRD ≥ 10-7 was observed in 19% (9/47). The median follow-up post-discontinuation was 30 months. Disease resurgence (MRD 10 ≥ -6) occurred in 11 patients, including 5 disease progressions. One patient died from a second cancer. The estimated 3-year cumulative incidence of disease resurgence was 20% for patients with baseline MRD < 10-7 compared to 75% for MRD ≥ 10-7 (HR 7.8, 95% CI 2.2-27.6, p = 0.001). Baseline MRD ≥ 10-7 was associated with inferior PFS compared to MRD < 10-7 (HR 10.1, 95% CI 1.6-62.3; 3-year PFS 49% vs 92%). Maintenance discontinuation in patients with MM and MRD < 10-6 led to low rates of disease resurgence. MRD < 10-7 may be a superior cessation threshold, requiring further validation.

Clinical implications of residual normal plasma cells within bone marrow across various disease stages in multiple myeloma

Residual normal plasma cells (NPCs), which compete with tumor plasma cells, play an important role in multiple myeloma. However, large-scale cohort studies investigating residual NPCs, especially at the minimal residual disease (MRD) phase, are currently lacking. In this study, we conducted a comprehensive investigation into the clinical significance of residual NPCs throughout the entire disease course in 1363 myeloma patients from the NICHE cohort (NCT04645199). Our results revealed that myeloma patients with high baseline NPCs ratio (≥5%) exhibited distinct indolent features, characterized by lower tumor burden, reduced frequencies of cytopenia, immunoparesis, and high-risk cytogenetics. Importantly, high residual NPCs ratio at diagnosis or relapse was independently associated with favorable survival. High absolute percentages of NPCs at undetectable MRD were related with superior clinical benefit and immune reconstitution. At MRD-positive phases, grouping based on NPCs ratio (<50%, 50-90%, ≥90%) demonstrated better risk stratification compared to residual tumor log levels. Based on the time-dependent NPCs ratio trend, we developed a dynamic MRD model that classifies patients into three groups with diverse longitudinal trends, leading to distinct prognoses. Collectively, residual NPCs serves not only as a valuable complementary biomarker for risk stratification but also provides valuable insights on reclassifications and kinetics of MRD.

Measurable Residual Disease Testing in Multiple Myeloma Following T-Cell Redirecting Therapies

Several novel T-cell-based therapies have recently become available for multiple myeloma (MM). These T-cell redirecting therapies (TRTs) include chimeric antigen receptor T-cells (CAR-T) and bispecific antibodies (BiAbs). In both clinical trial and real-world data, these therapies have demonstrated high rates of deep clinical response, and some are now approved for second-line treatment for relapsed MM. The deep and sustained clinical responses these therapies are capable of inducing will require sophisticated response monitoring to provide meaningful information for patient care. Obtaining measurable residual disease (MRD) negativity has been validated as an independent positive prognostic marker for progression-free survival (PFS) and overall survival (OS) in both newly diagnosed and relapsed refractory patients with multiple myeloma. Assessment for MRD negativity was performed in all of the trials for FDA-approved TRT. Here, we summarize pertinent data for MRD assessment following TRT in MM and provide a rationale and structured framework for conducting MRD testing post TRT.

First-Line Use of Daratumumab in Patients with Multiple Myeloma Shows Delayed Neutrophil and Platelet Engraftment after Autologous Stem Cell Transplantation: Results from a Real-Life Single-Center Study

BACKGROUND

This real-life study aimed to investigate the possible impact of D-VTd induction therapy on hematopoietic engraftment after autologous stem cell transplantation (auto-SCT).

METHODS

Sixty consecutive NDMM patients received four cycles of induction therapy with D-VTd. The conditioning regimen consisted of melphalan 200 mg/m2. These patients were compared with a historical control group of 80 patients who received four cycles of VTd as induction therapy.

RESULTS

The median days to reach neutrophil and platelet engraftment significantly differed between patients treated with D-VTd (11 and 13 days, respectively) and VTd (10 and 12 days). Univariate Cox analyses show that patients treated with D-VTd had a hazard ratio of neutrophil engraftment that was 42% significantly lower than those in the VTd arm (HR: 0.58, p = 0.002), and a multivariate model confirmed this result. Patients treated with D-VTd developed FN more frequently. Univariate and multivariate logistic regressions revealed an association between D-VTd and FN. Delayed engraftment did not correlate with more extended hospitalization. No patients died in the first six months after transplantation.

CONCLUSIONS

Our real-life study showed that a four-drug induction therapy containing DARA does not impact transplant safety outcomes.

Role of Autologous Transplant in Newly Diagnosed Multiple Myeloma Patients Treated with Novel Triplets: A Systematic Review and Meta-Analysis

INTRODUCTION

High-dose therapy with melphalan followed by autologous stem cell transplant in the upfront setting (upfront ASCT) has significantly improved clinical outcomes of myeloma patients and become the standard of care for the past 30 years. However, with the advent of modern induction therapy, the role of upfront ASCT approach has been called into question. Several prospective studies have examined whether continuing with triplet therapy as consolidation with optional ASCT at relapse (triplet-alone) could result in comparable outcomes.

METHODS

This was a systematic review and meta-analysis of randomized controlled trials comparing upfront ASCT versus triplet-alone approach among myeloma patients treated with triplet therapy, which included two novel agents and a corticosteroid, as induction. Cochrane Library, PubMed and conference proceedings were searched. Primary outcome was overall survival (OS). Secondary outcomes included progression-free survival (PFS), safety, and second primary malignancies (SPM). Subgroup analysis was conducted for high-risk cytogenetics.

RESULTS

Our search yielded three trials, conducted between 2010-2018, including 1,737 patients. Two trials evaluated bortezomib plus lenalidomide (VRd) induction and the third study tested carfilzomib plus lenalidomide (KRd) induction. Maintenance was given in all trials to both arms. There was no difference in OS between the arms; the pooled OS in all patients and those with high-risk cytogenetics was hazard ratio (HR) 1.03 (95% CI, 0.85-1.26; I2 = 0%; 1,737 patients, 3 trials) and 0.85 (95% CI, 0.59-1.23; I2 = 0%; 222 patients, 2 trials), respectively. The pooled PFS for upfront ASCT versus triplet-alone was significantly improved in all the patients and in the high-risk cytogenetics subgroup, HR 0.67 (95% CI 0.59-0.76; I2 = 0%; 1,737 patients, 3 trials) and HR 0.59 (95% CI: 0.44-0.7; I2 = 0%; 306 patients, 3 trials), respectively. The risk of any grade 3-4 adverse events was higher in the upfront ASCT arm versus triplet-alone approach (relative risk = 1.17 [95% CI, 1.12-1.23; 1,737 patients]). The risk of secondary malignancies was reported in all three trials and was comparable between both arms. Two trials reported on secondary myeloid neoplasms, which were significantly higher among upfront ASCT arm versus triplet-alone approach, OR 9.7 (1.8-52.25, I2 = 0%, 1,422 patients).

CONCLUSION

Although upfront ASCT approach, in the era of triplet therapy, resulted in a significantly longer PFS among all patients, this did not translate into a survival benefit, regardless of cytogenetic risk. Upfront ASCT was associated with an increased rate of secondary myeloid neoplasms. In the current plethora of innovative therapies, the role of upfront ASCT is debatable.

Quadruplet therapy for newly diagnosed myeloma: comparative analysis of sequential cohorts with triplet therapy lenalidomide, bortezomib and dexamethasone (RVd) versus daratumamab with RVD (DRVd) in transplant-eligible patients

Lenalidomide, bortezomib, and dexamethasone (RVd) have previously been established as standard-of-care induction therapy for newly diagnosed multiple myeloma (NDMM). More recently, randomized phase 3 data have demonstrated the benefit of the addition of daratumumab (Dara-RVd) to the RVd backbone in terms of improved both depth of response and long-term survival benefit as measured by progression-free survival (PFS). Our group has previously published on a historical cohort of 1000 NDMM patients uniformly treated with RVd induction with impressive both PFS and overall survival. Here, we present a comparative analysis of our RVd cohort with a recent cohort of 326 patients induced with Dara-RVd at our institution with intent to transplant. This analysis demonstrates the utility of this regimen in real-world clinical practice and provides additional insights into D-RVd performance in patient subsets often underrepresented in clinical trials, as well as the impact of daratumumab in maintenance for NDMM patients.

Risk-adapted treatment in multiple myeloma: Does more make it merrier?

Kaiser et al. offer management recommendations for transplant-eligible, high-risk multiple myeloma (HRMM), derived from recent trials exploring treatment intensification in the various phases of front-line therapy. The definition of HRMM continues to evolve with emergence of novel genomic insights and impact of modern therapies, underscoring the need to expand beyond traditional interphase fluorescence in situ hybridization cytogenetics and International Staging System staging for a precise risk assessment. Despite progress, ongoing challenges in treatment delivery and tolerability underscore the urgency for exploring novel approaches like T-cell redirecting bispecific antibodies and chimeric antigen receptor T-cell to enhance outcomes in this complex patient population. Commentary on: Kaiser et al. Diagnosis and initial treatment of transplant-eligible high-risk myeloma patients: A British Society for Haematology/UK Myeloma Society Good Practice Paper. Br J Haematol 2024; 205:833-839.

Effects of Daratumumab on Hematopoietic Stem Cells in Patients with Multiple Myeloma Who Are Planned to Receive Autologous Transplantation: What's the Relevance?

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Tandem Autologous Stem Cell Transplantation Does Not Benefit High-Risk Myeloma Patients in the Maintenance Era: Real-World Results from The Canadian Myeloma Research Group Database

In patients with multiple myeloma (MM), the presence of high-risk cytogenetic abnormalities is associated with worse disease control and survival. Autologous stem cell transplant (ASCT) does benefit these patients. Tandem transplantation has been explored as a means to deepen responses and further improve survival however, its role remains controversial. This is particularly true in the era of novel agent induction and post-transplant maintenance therapy. The aim of this study was to use the Canadian Myeloma Research Group database and examine a large cohort of real-world patients comparing the outcomes of tandem versus single ASCT specifically in high-risk patients receiving novel agent-based induction and post-transplant maintenance. The data for this study was derived retrospectively from a comprehensive national-level database of Canadian patients with MM. High-risk cytogenetics was defined as presence of del17p, t(4;14), or t(14;16). Those receiving allogeneic transplant were excluded. Tandem transplantation was defined as a second ASCT performed consecutively without interim relapse or progression after first ASCT. Those with relapse or progressive disease within 3 months of completing a first transplant were excluded. We compared response depth, progression-free, and overall survival (OS) based on single or tandem transplantation procedures. The impact of covariates of interest was also assessed. A total of 381 patients with high-risk cytogenetics were identified. A total of 242 received single and 139 patients received tandem transplants. All received post-transplant maintenance. The most common induction regimen for these patients was cyclophosphamide, bortezomib, and steroids (CyBorD, 87%). Forty-one patients (10.8%) required reinduction prior to first ASCT. The best overall responses at any time were 98.3% (90.5% ≥ very good partial response [VGPR]) and 98.6% (89.9% ≥ VGPR) in the single and tandem ASCT groups, respectively. Survival outcomes were similar with the median progression-free survival for single or tandem ASCT of 35.2 and 35.3 months (P = .88) and the median OS were 92.6 and 88.9 months, respectively (P = .72). No statistically significant differences were seen based on type of cytogenetic abnormality or type of maintenance. This was confirmed on multivariate analysis. In the real-world setting, tandem ASCT does not improve outcomes for MM patients with high-risk cytogenetics. This may be driven by the use of effective pre- and post-ASCT therapies. The development of more potent induction and consolidation along with current nearly ubiquitous continuous maintenance therapies until disease progression does not support the use of a second high-dose procedure.

Comparative Meta-Analysis of Triplet vs. Quadruplet Induction Regimens in Newly Diagnosed, Treatment Naïve, Multiple Myeloma

The use of 4-drug induction regimens for treatment naïve newly diagnosed multiple myeloma (NDMM) is associated with improved depth of response and progression-free survival (PFS). However, head-to-head trials of 4-drug combinations are lacking, and instead, these regimens are typically compared to 3-drug backbones; limiting the ability to discern whether any additional benefit (or toxicity) is simply additive or represents a synergy (or interaction). We conducted a meta-analysis of phase 2 and phase 3 clinical trials that randomized treatment naïve NDMM patients to either a 4-drug or 3-drug induction regimen. We included 11 trials which represented 6509 unique patients. PFS for all trials in the meta-analysis was 54 months with a 4-drug induction and 8.9 months with a 3-drug induction (HR: 0.49; 95% CI: 0.45; 0.54), but there was no benefit to using a 4-drug induction that did not include an anti-CD38 antibody (PFS 4-drug 8.1 months, PFS 3-drug 8.0 months; HR 0.95; 95% CI 0.86; 1.06). Adverse events were more frequent with the quadruplet regimens but were predominately mild. High-grade (≥3) adverse events (AEs) that were more common with 4-drug regimens were infections (RR: 1.34; 95% CI 1.17; 1.54) and thrombocytopenia (RR: 1.39; 95% CI 1.12; 1.74). This study suggests that 4-drug induction regimens which include an anti-CD38 antibody improve efficacy although with additional toxicity in NDMM patients.