Up-front carfilzomib, lenalidomide, and dexamethasone with transplant for patients with multiple myeloma: the IFM KRd final results

Bortezomib, lenalidomide, and dexamethasone plus transplant is a standard of care for eligible patients with multiple myeloma. Because responses can deepen with time, regimens with longer and more potent induction/consolidation phases are needed. In this phase 2 study, patients received eight 28-day cycles of carfilzomib (K) 20/36 mg/m2 (days 1-2, 8-9, 15-16), lenalidomide (R) 25 mg (days 1-21), and dexamethasone (d) 20 mg (days 1-2, 8-9, 15-16, 22-23). All patients proceeded to transplant after 4 cycles and received 1 year of lenalidomide maintenance (10 mg, days 1-21). The primary objective was stringent complete response at the completion of consolidation. Overall, 48 patients were screened and 46 enrolled; 21% had adverse cytogenetics. Among 42 evaluable patients after consolidation, 26 were in stringent complete response (CR; 61.9%), 27 were at least in CR (64.3%): 92.6% had undetectable minimal residual disease according to flow cytometry (≥2.5 × 10-5) and 63.0% according to next-generation sequencing (10-6). Median time to CR was 10.6 months. According to multiparametric flow cytometry and next-generation sequencing, 69.0% and 66.7% of patients, respectively, had undetectable minimal residual disease at some point. With a median follow-up of 60.5 months, 21 patients progressed, and 10 died (7 of multiple myeloma). Median progression-free survival was 56.4 months. There were no KRd-related deaths. Four patients discontinued the program due to toxicities; 56 serious adverse events were reported in 31 patients, including 8 cardiovascular events (2 heart failures, 5 pulmonary embolisms or deep vein thrombosis). Common grade 3/4 adverse events were hematologic (74%) and infectious (22%). In summary, 8 cycles of KRd produce fast and deep responses in transplant-eligible patients with newly diagnosed multiple myeloma. The safety profile is acceptable, but cardiovascular adverse events should be closely monitored. This clinical trial is registered at www.clinicaltrials.gov as #NCT02405364.

Quantification of measurable residual disease in patients with multiple myeloma based on the IMWG response criteria

Stringent complete response (sCR) is defined as a deeper response than complete response (CR) in multiple myeloma. Whether achieving sCR correlates with better survival remains controversial. We evaluated the outcomes in patients with intact immunoglobulin multiple myeloma (IIMM) and light chain multiple myeloma (LCMM) who achieved a very good partial response (VGPR) or better. Multicolour flow cytometry was used to assess the depth of response. LCMM patients with sCR had significantly lower measurable residual disease (MRD) levels than those with CR (median MRD: 7.9 × 10^-4 vs. 5.6 × 10^-5, P < 0.01). Nonetheless, no significant difference was observed in MRD levels across the responses in groups of patients with IIMM (VGPR vs. CR: 3.5 × 10^-4 vs. 7.0 × 10^-5, P = 0.07; CR vs. sCR: 7.0 × 10^-5 vs. 5.4 × 10^-5, P = 0.81. In accordance with MRD levels, the median overall survival of patients with sCR was significantly longer (sCR, CR, VGPR; not reached, 41 months, and 58 months, respectively; VGPR vs. CR, P = 0.83; CR vs. sCR, P = 0.04) in LCMM, but not in IIMM (sCR, CR, VGPR; not reached, 41 months, and not reached, respectively; VGPR vs. CR, P = 0.59; CR vs. sCR; P = 0.10). Our results show that sCR represents a deeper response that correlates with longer survival in patients with LCMM, but not IIMM.

Prognostic value of minimal residual disease negativity in myeloma: combined analysis of POLLUX, CASTOR, ALCYONE, MAIA

We explored minimal residual disease (MRD) in relapsed/refractory multiple myeloma (RRMM) and transplant-ineligible newly diagnosed multiple myeloma (TIE NDMM) using data from four phase 3 studies (POLLUX, CASTOR, ALCYONE, and MAIA). Each study previously demonstrated that daratumumab-based therapies improved MRD-negativity rates and reduced the risk of disease progression or death by approximately half versus standards of care. We conducted a large-scale pooled analysis for associations between patients achieving complete response (CR) or better with MRD-negative status, and progression-free survival (PFS). MRD was assessed via next-generation sequencing (10‒5 threshold). Patient-level data were pooled from all four studies, and for patients with TIE NDMM plus patients with RRMM who received ≤2 prior lines of therapy (≤2PL). PFS was evaluated by response and MRD status. Median follow-up (months) was: POLLUX, 54.8; CASTOR, 50.2; ALCYONE, 40.1; and MAIA, 36.4. Patients who achieved ≥CR and MRD negativity had improved PFS versus those who failed to reach CR or were MRD positive (TIE NDMM and RRMM hazard ratio [HR] 0.20, P < .0001; TIE NDMM and RRMM ≤2PL HR 0.20, P < .0001). This benefit occurred irrespective of therapy or disease setting. A time-varying Cox proportional hazard model confirmed that ≥CR with MRD negativity was associated with improved PFS. Daratumumab-based treatment was associated with more patients reaching ≥CR and MRD negativity. These findings represent the first large-scale analysis with robust methodology to support ≥CR with MRD negativity as a prognostic factor for PFS in RRMM and TIE NDMM. These trials were registered at www.ClinicalTrials.gov: NCT02076009/NCT02136134/NCT02195479/NCT02252172.

Sustained Minimal Residual Disease Negativity With Daratumumab in Newly Diagnosed Multiple Myeloma: MAIA and ALCYONE

In patients with transplant-ineligible NDMM, durable MRD negativity is associated with improved PFS.

Daratumumab-based therapies are associated with higher rates and durability of MRD negativity.

In patients with transplant-ineligible newly diagnosed multiple myeloma (NDMM), daratumumab reduced the risk of disease progression or death by 44% in MAIA (daratumumab/lenalidomide/dexamethasone [D-Rd]) and 58% in ALCYONE (daratumumab/bortezomib/melphalan/prednisone [D-VMP]). Minimal residual disease (MRD) is a sensitive measure of disease and response to therapy. MRD-negativity status and durability were assessed in MAIA and ALCYONE. MRD assessments using next-generation sequencing (10⁻⁵) occurred for patients achieving complete response (CR) or better and after at least CR at 12, 18, 24, and 30 months from the first dose. Progression-free survival (PFS) by MRD status and sustained MRD negativity lasting ≥6 and ≥12 months were analyzed in the intent-to-treat population and among patients achieving at least CR. In MAIA (D-Rd, n = 368; lenalidomide and dexamethasone [Rd], n = 369) and ALCYONE (D-VMP, n = 350; bortezomib/melphalan/prednisone [VMP], n = 356), the median duration of follow-up was 36.4 and 40.1 months, respectively. MRD-negative status and sustained MRD negativity lasting ≥6 and ≥12 months were associated with improved PFS, regardless of treatment group. However, daratumumab-based therapy improved rates of MRD negativity lasting ≥6 months (D-Rd, 14.9% vs Rd, 4.3%; D-VMP, 15.7% vs VMP, 4.5%) and ≥12 months (D-Rd, 10.9% vs Rd, 2.4%; D-VMP, 14.0% vs VMP, 2.8%), both of which translated to improved PFS vs control groups. In a pooled analysis, patients who were MRD negative had improved PFS vs patients who were MRD positive. Patients with NDMM who achieved MRD-negative status or sustained MRD negativity had deep remission and improved clinical outcomes. These trials were registered at www.clinicaltrials.gov as #NCT02252172 (MAIA) and #NCT02195479 (ALCYONE).

Next-Generation Biomarkers in Multiple Myeloma: Understanding the Molecular Basis for Potential Use in Diagnosis and Prognosis

Multiple myeloma (MM) is considered to be the second most common blood malignancy and it is characterized by abnormal proliferation and an accumulation of malignant plasma cells in the bone marrow. Although the currently utilized markers in the diagnosis and assessment of MM are showing promising results, the incidence and mortality rate of the disease are still high. Therefore, exploring and developing better diagnostic or prognostic biomarkers have drawn global interest. In the present review, we highlight some of the recently reported and investigated novel biomarkers that have great potentials as diagnostic and/or prognostic tools in MM. These biomarkers include angiogenic markers, miRNAs as well as proteomic and immunological biomarkers. Moreover, we present some of the advanced methodologies that could be utilized in the early and competent diagnosis of MM. The present review also focuses on understanding the molecular concepts and pathways involved in these biomarkers in order to validate and efficiently utilize them. The present review may also help in identifying areas of improvement for better diagnosis and superior outcomes of MM.

Immune Gene Rearrangements: Unique Signatures for Tracing Physiological Lymphocytes and Leukemic Cells

The tremendous diversity of the human immune repertoire, fundamental for the defense against highly heterogeneous pathogens, is based on the ingenious mechanism of immune gene rearrangements. Rearranged immune genes encoding the immunoglobulins and T-cell receptors and thus determining each lymphocyte's antigen specificity are very valuable molecular markers for tracing malignant or physiological lymphocytes. One of their most significant applications is tracking residual leukemic cells in patients with lymphoid malignancies. This so called 'minimal residual disease' (MRD) has been shown to be the most important prognostic factor across various leukemia subtypes and has therefore been given enormous attention. Despite the current rapid development of the molecular methods, the classical real-time PCR based approach is still being regarded as the standard method for molecular MRD detection due to the cumbersome standardization of the novel approaches currently in progress within the EuroMRD and EuroClonality NGS Consortia. Each of the molecular methods, however, poses certain benefits and it is therefore expectable that none of the methods for MRD detection will clearly prevail over the others in the near future.

Pretransplant Determinants of Outcome in Patients with Myeloma Undergoing Autologous Transplantation in Lower Resource Settings

The treatment landscape in multiple myeloma has significantly changed since the introduction of high-dose melphalan with autologous stem cell rescue in the 1980s. Many randomised controlled trials have clearly demonstrated the superiority of autologous stem cell transplantation in improving survival compared to conventional chemotherapy. However, outcomes in myeloma are highly variable with median survival as short as 2 years and as long as 10 years or more. The main adverse factor predicting shorter survival is presence of high-risk cytogenetics. However, there are many other potential factors that can contribute to the treatment outcomes.  This review looks at the various pretransplant variables that are associated with  post-transplant outcomes in myeloma.

A large meta-analysis establishes the role of MRD negativity in long-term survival outcomes in patients with multiple myeloma

The prognostic value of minimal residual disease (MRD) for progression-free survival (PFS) and overall survival (OS) was evaluated in a large cohort of patients with multiple myeloma (MM) using a systematic literature review and meta-analysis. Medline and EMBASE databases were searched for articles published up to 8 June 2019, with no date limit on the indexed database. Clinical end points stratified by MRD status (positive or negative) were extracted, including hazard ratios (HRs) on PFS and OS, P values, and confidence intervals (CIs). HRs were estimated based on reconstructed patient-level data from published Kaplan-Meier curves. Forty-four eligible studies with PFS data from 8098 patients, and 23 studies with OS data from 4297 patients were identified to assess the association between MRD status and survival outcomes. Compared with MRD positivity, achieving MRD negativity improved PFS (HR, 0.33; 95% CI, 0.29-0.37; P < .001) and OS (HR, 0.45; 95% CI, 0.39-0.51; P < .001). MRD negativity was associated with significantly improved survival outcomes regardless of disease setting (newly diagnosed or relapsed/refractory MM), MRD sensitivity thresholds, cytogenetic risk, method of MRD assessment, depth of clinical response at the time of MRD measurement, and MRD assessment premaintenance and 12 months after start of maintenance therapy. The strong prognostic value of MRD negativity and its association with favorable outcomes in various disease and treatment settings sets the stage to adopt MRD as a treatment end point, including development of therapeutic strategies. This large meta-analysis confirms the utility of MRD as a relevant surrogate for PFS and OS in MM.

Clinical value of minimal residual disease assessed by multiparameter flow cytometry in amyloid light chain amyloidosis

PURPOSE

To assess the feasibility and prognostic value of minimal residual disease (MRD) evaluated by multiparameter flow cytometry (MFC) in newly diagnosed amyloid light chain (AL) amyloidosis.

METHODS

Clinical data from 25 consecutive newly diagnosed AL amyloidosis patients with MRD data tested at 3 months after first-line therapy completion were retrospectively analysed in a single centre from 2012 to 2019. First-line therapy included 8 courses of VD or 4 courses of VD plus sequential autologous stem cell transplantation (ASCT), both without maintenance therapy.

RESULTS

Of 25 patients with very good partial response (VGPR) or better, 19 (76%) achieved MRD negativity. Baseline characteristics were not different between MRD-negative and MRD-positive patients. More ASCT patients than non-ASCT patients (90.0% vs 53.3%, p = 0.043) achieved MRD negativity. In the MRD-negative and MRD-positive groups, cardiac response was observed in 93% and 25% (p = 0.019) and any organ response in 94% and 50%, respectively (p = 0.023). At a median follow-up of 25.1 months, MRD-negative patients showed significantly longer progression-free survival (PFS) from diagnosis than MRD-positive patients (24.52 vs 76.39 months, p = 0.004).

CONCLUSIONS

MRD negativity measured by MFC at 3 months after first-line therapy completion in patients with AL amyloidosis is measurable and associated with improved organ response rates and PFS over a long follow-up.

Carfilzomib or bortezomib in combination with cyclophosphamide and dexamethasone followed by carfilzomib maintenance for patients with multiple myeloma after one prior therapy: results from a multi-centre, phase II, randomized, controlled trial (MUKfive)

The proteasome inhibitors, carfilzomib and bortezomib, are widely used to treat myeloma but head-to-head comparisons have produced conflicting results. We compared the activity of these proteasome inhibitors in combination with cyclophosphamide and dexamethasone (KCd vs. VCd) in second-line treatment using fixed duration therapy and evaluated the efficacy of carfilzomib maintenance. MUKfive was a phase II controlled, parallel group trial that randomized patients (2:1) to KCd (n=201) or VCd (n=99); responding patients on carfilzomib were randomized to maintenance carfilzomib (n=69) or no further treatment (n=72). Primary endpoints were: (i) very good partial response (non-inferiority, odds ratio [OR] 0.8) at 24 weeks, and (ii) progression-free survival. More participants achieved a very good partial response or better with carfilzomib than with bortezomib (40.2% vs. 31.9%, OR=1.48, 90% confidence interval [CI]: 0.95, 2.31; non-inferior), with a trend for particular benefit in patients with adverse-risk disease. KCd was associated with higher overall response (partial response or better, 84.0% vs. 68.1%, OR=2.72, 90% CI: 1.62, 4.55, P=0.001). Neuropathy (grade ≥3 or ≥2 with pain) was more common with bortezomib (19.8% vs. 1.5%, P<0.0001), while grade ≥3 cardiac events and hypertension were only reported in the KCd arm (3.6% each). The median progression-free survival in the KCd arm was 11.7 months vs. 10.2 months in the VCd arm (hazard ratio [HR]=0.95, 80% CI: 0.77, 1.18). Carfilzomib maintenance was associated with longer progression-free survival, median 11.9 months vs. 5.6 months for no maintenance (HR 0.59, 80% CI: 0.46-0.77, P=0.0086). When used as fixed duration therapy in first relapase, KCd is at least as effective as VCd, and carfilzomib is an effective maintenance agent. This trial was registered with International Standard Randomised Controlled Trial Number (ISRCTN) identifier: ISRCTN17354232.

MUKnine OPTIMUM protocol: a screening study to identify high-risk patients with multiple myeloma suitable for novel treatment approaches combined with a phase II study evaluating optimised combination of biological therapy in newly diagnosed high-risk multiple myeloma and plasma cell leukaemia

INTRODUCTION

Multiple myeloma (MM) is a plasma cell tumour with over 5800 new cases each year in the UK. The introduction of biological therapies has improved outcomes for the majority of patients with MM, but in approximately 20% of patients the tumour is characterised by genetic changes which confer a significantly poorer prognosis, generally termed high-risk (HR) MM. It is important to diagnose these genetic changes early and identify more effective first-line treatment options for these patients.

METHODS AND ANALYSIS

The Myeloma UK nine OPTIMUM trial (MUKnine) evaluates novel treatment strategies for patients with HRMM. Patients with suspected or newly diagnosed MM, fit for intensive therapy, are offered participation in a tumour genetic screening protocol (MUKnine a), with primary endpoint proportion of patients with molecular screening performed within 8 weeks. Patients identified as molecularly HR are invited into the phase II, single-arm, multicentre trial (MUKnine b) investigating an intensive treatment schedule comprising bortezomib, lenalidomide, daratumumab, low-dose cyclophosphamide and dexamethasone, with single high-dose melphalan and autologous stem cell transplantation (ASCT) followed by combination consolidation and maintenance therapy. MUKnine b primary endpoints are minimal residual disease (MRD) at day 100 post-ASCT and progression-free survival. Secondary endpoints include response, safety and quality of life. The trial uses a Bayesian decision rule to determine if this treatment strategy is sufficiently active for further study. Patients identified as not having HR disease receive standard treatment and are followed up in a cohort study. Exploratory studies include longitudinal whole-body diffusion-weighted MRI for imaging MRD testing.

ETHICS AND DISSEMINATION

Ethics approval London South East Research Ethics Committee (Ref: 17/LO/0022, 17/LO/0023). Results of studies will be submitted for publication in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

ISRCTN16847817, May 2017; Pre-results.

Daratumumab, lenalidomide, bortezomib, and dexamethasone for transplant-eligible newly diagnosed multiple myeloma: the GRIFFIN trial

Lenalidomide, bortezomib, and dexamethasone (RVd) followed by autologous stem cell transplantation (ASCT) is standard frontline therapy for transplant-eligible patients with newly diagnosed multiple myeloma (NDMM). The addition of daratumumab (D) to RVd (D-RVd) in transplant-eligible NDMM patients was evaluated. Patients (N = 207) were randomized 1:1 to D-RVd or RVd induction (4 cycles), ASCT, D-RVd or RVd consolidation (2 cycles), and lenalidomide or lenalidomide plus D maintenance (26 cycles). The primary end point, stringent complete response (sCR) rate by the end of post-ASCT consolidation, favored D-RVd vs RVd (42.4% vs 32.0%; odds ratio, 1.57; 95% confidence interval, 0.87-2.82; 1-sided P = .068) and met the prespecified 1-sided α of 0.10. With longer follow-up (median, 22.1 months), responses deepened; sCR rates improved for D-RVd vs RVd (62.6% vs 45.4%; P = .0177), as did minimal residual disease (MRD) negativity (10-5 threshold) rates in the intent-to-treat population (51.0% vs 20.4%; P < .0001). Four patients (3.8%) in the D-RVd group and 7 patients (6.8%) in the RVd group progressed; respective 24-month progression-free survival rates were 95.8% and 89.8%. Grade 3/4 hematologic adverse events were more common with D-RVd. More infections occurred with D-RVd, but grade 3/4 infection rates were similar. Median CD34+ cell yield was 8.2 × 106/kg for D-RVd and 9.4 × 106/kg for RVd, although plerixafor use was more common with D-RVd. Median times to neutrophil and platelet engraftment were comparable. Daratumumab with RVd induction and consolidation improved depth of response in patients with transplant-eligible NDMM, with no new safety concerns. This trial was registered at www.clinicaltrials.gov as #NCT02874742.

Minimal residual disease in multiple myeloma: defining the role of next generation sequencing and flow cytometry in routine diagnostic use

For patients diagnosed with multiple myeloma (MM) there have been significant treatment advances over the past decade, reflected in an increasing proportion of patients achieving durable remissions. Clinical trials repeatedly demonstrate that achieving a deep response to therapy, with a bone marrow assessment proving negative for minimal residual disease (MRD), confers a significant survival advantage. To accurately assess for minute quantities of residual cancer requires highly sensitive methods; either multiparameter flow cytometry or next generation sequencing are currently recommended for MM response assessment. Under optimal conditions, these methods can detect one aberrant cell amongst 1,000,000 normal cells (a sensitivity of 10^-6). Here, we will review the practical use of MRD assays in MM, including challenges in implementation for the routine diagnostic laboratory, standardisation across laboratories and clinical trials, the clinical integration of MRD status assessment into MM management and future directions for ongoing research.

Defining the undetectable: The current landscape of minimal residual disease assessment in multiple myeloma and goals for future clarity

Multiple Myeloma, the second most prevalent hematologic malignancy, yet lacks an established curative therapy. However, overall response rate to modern four-drug regimens approaches 100%. Major efforts have thus focused on the measurement of minute quantities of residual disease (minimal residual disease or MRD) for prognostic metrics and therapeutic response evaluation. Currently, MRD is assessed by flow cytometry or by next generation sequencing to track tumor-specific immunoglobulin V(D)J rearrangements. These bone marrow-based methods can reach sensitivity thresholds of the identification of one neoplastic cell in 1,000,000 (10-6). New technologies are being developed to be used alone or in conjunction with established methods, including peripheral blood-based assays, mass spectrometry, and targeted imaging. Data is also building for MRD as a surrogate endpoint for overall survival. Here, we will address the currently utilized MRD assays, challenges in validation across labs and clinical trials, techniques in development, and future directions for successful clinical application of MRD in multiple myeloma.

Mass spectrometry for the evaluation of monoclonal proteins in multiple myeloma and related disorders: an International Myeloma Working Group Mass Spectrometry Committee Report

Plasma cell disorders (PCDs) are identified in the clinical lab by detecting the monoclonal immunoglobulin (M-protein) which they produce. Traditionally, serum protein electrophoresis methods have been utilized to detect and isotype M-proteins. Increasing demands to detect low-level disease and new therapeutic monoclonal immunoglobulin treatments have stretched the electrophoretic methods to their analytical limits. Newer techniques based on mass spectrometry (MS) are emerging which have improved clinical and analytical performance. MS is gaining traction into clinical laboratories, and has replaced immunofixation electrophoresis (IFE) in routine practice at one institution. The International Myeloma Working Group (IMWG) Mass Spectrometry Committee reviewed the literature in order to summarize current data and to make recommendations regarding the role of mass spectrometric methods in diagnosing and monitoring patients with myeloma and related disorders. Current literature demonstrates that immune-enrichment of immunoglobulins coupled to intact light chain MALDI-TOF MS has clinical characteristics equivalent in performance to IFE with added benefits of detecting additional risk factors for PCDs, differentiating M-protein from therapeutic antibodies, and is a suitable replacement for IFE for diagnosing and monitoring multiple myeloma and related PCDs. In this paper we discuss the IMWG recommendations for the use of MS in PCDs.

Measurable residual disease in multiple myeloma and light chain amyloidosis: more than meets the eye

The emergence of highly effective multiple myeloma (MM) treatments may bring cure within reach and highlights the need for highly sensitive measurable residual disease (MRD) techniques to replace conventional response assessments. MRD is being incorporated as an endpoint in an increasing number of studies and had been repeatedly shown to be both a predictive marker of response to treatment and a prognostic marker for future relapse. However, those results should be cautiously interpreted due to non-uniform reporting and the need for longer follow up to assess for sustained MRD negativity. This review aims to critically analyze the key MRD aspects including the current evidence supporting the use of MRD in clinical practice and the pitfalls of the various methods used to assess MRD. The utility of MRD for light chain (AL) amyloidosis will also be discussed.

Thalidomide-induced serious RR interval prolongation (longest interval >5.0 s) in multiple myeloma patient with rectal cancer: A case report

Primary secondary tumor increased recently with the use of immunomodulatory drugs in patients with multiple myeloma (MM). However, MM with prior diagnosis of primary secondary tumor is relatively rare. In this study, we reported an MM patient with prior diagnosis of rectal cancer. In brief, an 85-year-old man was first diagnosed with rectal cancer. Given the age, heart failure and small-cell hypochromic anemia (hemoglobin level: 54 g/L), rectal cancer resection was not advised and symptomatic treatments were performed (including sufficient iron supplementation). Eight months later, the patient was diagnosed with MM due to worsening anemia. Anemia and heart failure were corrected after three cycles of treatment with thalidomide, dexamethasone and capecitabine. Radical resection of rectal carcinoma (Hartmann) was finally performed due to acute abdominal distension. Meanwhile, RR interval prolongation (longest interval >5.0 s) and atrial fibrillation occurred in the fifth cycle treatment. One month after discontinuation of thalidomide, RR interval returned to normal range, while atrial fibrillation developed into persistent atrial fibrillation.

Multiple Myeloma, Version 3.2021, NCCN Clinical Practice Guidelines in Oncology

Multiple myeloma is a malignant neoplasm of plasma cells that accumulate in bone marrow, leading to bone destruction and marrow failure. This manuscript discusses the management of patients with solitary plasmacytoma, smoldering multiple myeloma, and newly diagnosed multiple myeloma.

Clinical and prognostic significance of t(4;14) translocation in multiple myeloma in the era of novel agents

Translocation t(4;14) is an independent prognostic factor for adverse outcome in multiple myeloma (MM). However, reports concerning the therapeutic effects of novel drugs on t(4;14) MM are few. We retrospectively investigated the clinical and prognostic significance of symptomatic MM cases with t(4;14) treated with novel therapies. Ninety-three patients (IgG, 56; IgA, 23; BjP, 14) newly diagnosed with MM were included (median age, 71 years; median observation period, 27.8 months). t(4;14) MM was diagnosed in 17 (IgG, 7; IgA, 9; BjP, 1) patients (18%). An association between t(4;14) and the IgA isotype was confirmed (p = 0.02). Overall survival (OS) at 3 years was lower in the t(4;14) patients than without t(4;14) group (81.2% vs 66.7%, p = 0.04). Multivariate analysis showed that t(4;14) was an independent predictor of OS (hazard ratio [HR], 7.58; 95.0% confidence interval [CI], 1.43-39.9; p = 0.0017). The ORR after autologous blood stem cell transplantation (ASCT) did not differ with or without t(4;14); progression-free survival tended to be prolonged in the group without t(4;14) (p = 0.088). Thus, even in the era of novel drugs, t(4;14) MM still has a poor prognosis, and triplet consolidation therapy should be continued.

Minimal Residual Disease in Multiple Myeloma: State of the Art and Applications in Clinical Practice

Novel drugs have revolutionized multiple myeloma therapy in the last 20 years, with median survival that has doubled to up to 8–10 years. The introduction of therapeutic strategies, such as consolidation and maintenance after autologous stem cell transplants, has also ameliorated clinical results. The goal of modern therapies is becoming not only complete remission, but also the deepest possible remission. In this context, the evaluation of minimal residual disease by techniques such as next-generation sequencing (NGS) and next-generation flow (NGF) is becoming part of all new clinical trials that test drug efficacy. This review focuses on minimal residual disease approaches in clinical trials, with particular attention to real-world practices.

The clinical significance of stringent complete response in multiple myeloma is surpassed by minimal residual disease measurements

Background

Stringent complete response (sCR) is used as a deeper response category than complete response (CR) in multiple myeloma (MM) but may be of limited value in the era of minimal residual disease (MRD) testing.

Methods

Here, we used 4-colour multiparametric flow cytometry (MFC) or next-generation sequencing (NGS) of immunoglobulin genes to analyse and compare the prognostic impact of sCR and MRD monitoring. We included 193 treated patients in two institutions achieving CR, for which both bone marrow aspirates and biopsies were available.

Results

We found that neither the serum free light chain ratio, clonality by immunohistochemistry (IHC) nor plasma cell bone marrow infiltration identified CR patients at distinct risk. Patients with sCR had slightly longer progression-free survival. Nevertheless, persistent clonal bone marrow disease was detectable using MFC or NGS and was associated with significantly inferior outcomes compared with MRD-negative cases.

Conclusion

Our results confirm that sCR does not predict a different outcome and indicate that more sensitive techniques are able to identify patients with differing prognoses. We suggest that MRD categories should be implemented over sCR for the future classification of MM responses.

An evaluation of subcutaneous daratumumab for the treatment of multiple myeloma

INTRODUCTION

A subcutaneous formulation of daratumumab, a human immunoglobulin G1 kappa monoclonal antibody targeting CD38, recently achieved FDA approval for both newly diagnosed and relapsed refractory multiple myeloma amid promises to decrease infusion times and rates of infusion reactions in myeloma patients.

AREAS COVERED

In this article the biology behind subcutaneous administration of oncologic antibody therapies is reviewed and the subcutaneous formulation of daratumumab is covered in depth. The most recent results from the PAVO, COLUMBA, and PLEIADES clinical trials evaluating subcutaneous daratumumab as a single agent, and in combination, in both newly diagnosed, and relapsed and refractory myeloma patients are summarized. The efficacy, safety, and PK data from these trials are reviewed, and the potential of the subcutaneous formulation to improve quality of life in myeloma patients and decrease healthcare resource use is discussed.

EXPERT OPINION

Subcutaneous daratumumab is non-inferior to conventional intravenous daratumumab with lower risk of infusion-related reactions and decreased administration time. Based on these data, and the recent FDA and European Commission approvalsthe widespread use of the subcutaneous formulation for both conventional and investigational practice is supported.

Time to Redefine Risk-Stratification and Response Criteria in Immunoglobulin Light Chain Amyloidosis?

Immunoglobulin light chain (AL) amyloidosis results from clonal plasma cell (PC)-derived immunoglobulin light chain-mediated end-organ dysfunction, the extent and severity of which predicts survival. Anti-PC therapies reduce clonal light chain burden, which usually results in improvement of organ function, and consequently overall survival. Response assessment is critical to gauge therapeutic efficacy, to report clinical trial outcomes, and to switch therapy in those without response. Response in AL amyloidosis is 2-fold: hematologic response and organ response (OR). Depth of hematologic response is graded on the basis of serum free light chain (sFLC) parameters, but assessment of OR is binary. The role of normal sFLC ratio or complete remission as a treatment end point has been challenged, thus highlighting the need to quantify involved FLC and residual PC beyond the normal sFLC ratio to possibly account for the ongoing organ damage seen in some patients with complete remission. Mass spectrometry and urinary exosome represent ultrasensitive strategies to estimate involved FLC below the detection threshold of current sFLC assays. The role of new sFLC parameters and minimal residual disease as potential prognostic parameters has been recognized. Brain natriuretic peptide (BNP) and 24-hour proteinuria:estimated glomerular filtration rate ratio were identified to overcome certain limitations of N-terminal-Pro-BNP, 24-hour proteinuria, and estimated glomerular filtration rate for cardiac and renal response assessment, respectively. Use of monoclonal antibodies targeting PC and amyloid deposits has expanded the therapeutic armamentarium of AL amyloidosis, and given their excellent efficacy, early ORs are reported. This review provides insights into recent advances in the risk-stratification and response assessment of patients with AL amyloidosis in light of the changing therapeutic paradigms. Incorporation of these advancements into formal consensus guidelines would require further validation.

Characterization of circulating myeloma tumor cells by next generation flowcytometry in scleromyxedema patient: a case report

INTRODUCTION

Scleromyxedema (rare cutaneous mucinosis), is characterized by the formation of lichenoid papules and presence of Serum monoclonal IgG in most cases, or all; after repeated testing.

PATIENT CONCERNS

The patient is a 51-year-old male presented with thick, disfiguring elephant-like erythematous skin folds over the forehead, papular shiny eruptions over ears and trunk and waxy erythematous papules over arms and hands without dysphagia or respiratory or neurologic symptoms DIAGNOSIS: : Skin biopsy from right arm was consistent with scleromyxedema. Serum cryoglobulin was reported negative. Complete blood count and routine blood biochemistry were normal. Thyroid function tests were normal. Serum protein electrophoresis and immunofixation showed monoclonal band of 14.5 g/L typed as IgG lambda.

INTERVENTIONS

Our patient was refractory to lenalidomide however improved clinically on immunoglobulins infusions on monthly basis without change in the MGUS level.

OUTCOMES

NGF analysis revealed approximately 0.25% Lambda monotypic plasma cells in the bone marrow expressing CD38, CD138, and CD27 with aberrant expression of CD56 and were negative for CD45, CD19, CD117, and CD81. We also detected 0.002% circulating plasma cells (PCs) in peripheral blood.

CONCLUSION

The immunophenotype of circulating tumor cells (CTCs) remain close to the malignant PCs phenotype in the BM. Hence, we report NGF approach as a novel diagnostic tool for highly sensitive MRD detection in plasma cell dyscrasias including scleromyxedema.

Analytical evaluation of the clonoSEQ Assay for establishing measurable (minimal) residual disease in acute lymphoblastic leukemia, chronic lymphocytic leukemia, and multiple myeloma

Background

The clonoSEQ® Assay (Adaptive Biotechnologies Corporation, Seattle, USA) identifies and tracks unique disease-associated immunoglobulin (Ig) sequences by next-generation sequencing of IgH, IgK, and IgL rearrangements and IgH-BCL1/2 translocations in malignant B cells. Here, we describe studies to validate the analytical performance of the assay using patient samples and cell lines.

Methods

Sensitivity and specificity were established by defining the limit of detection (LoD), limit of quantitation (LoQ) and limit of blank (LoB) in genomic DNA (gDNA) from 66 patients with multiple myeloma (MM), acute lymphoblastic leukemia (ALL), or chronic lymphocytic leukemia (CLL), and three cell lines. Healthy donor gDNA was used as a diluent to contrive samples with specific DNA masses and malignant-cell frequencies. Precision was validated using a range of samples contrived from patient gDNA, healthy donor gDNA, and 9 cell lines to generate measurable residual disease (MRD) frequencies spanning clinically relevant thresholds. Linearity was determined using samples contrived from cell line gDNA spiked into healthy gDNA to generate 11 MRD frequencies for each DNA input, then confirmed using clinical samples. Quantitation accuracy was assessed by (1) comparing clonoSEQ and multiparametric flow cytometry (mpFC) measurements of ALL and MM cell lines diluted in healthy mononuclear cells, and (2) analyzing precision study data for bias between clonoSEQ MRD results in diluted gDNA and those expected from mpFC based on original, undiluted samples. Repeatability of nucleotide base calls was assessed via the assay’s ability to recover malignant clonotype sequences across several replicates, process features, and MRD levels.

Results

LoD and LoQ were estimated at 1.903 cells and 2.390 malignant cells, respectively. LoB was zero in healthy donor gDNA. Precision ranged from 18% CV (coefficient of variation) at higher DNA inputs to 68% CV near the LoD. Variance component analysis showed MRD results were robust, with expected laboratory process variations contributing ≤3% CV. Linearity and accuracy were demonstrated for each disease across orders of magnitude of clonal frequencies. Nucleotide sequence error rates were extremely low.

Conclusions

These studies validate the analytical performance of the clonoSEQ Assay and demonstrate its potential as a highly sensitive diagnostic tool for selected lymphoid malignancies.

Perspectives in the Rapidly Evolving Treatment Landscape of Multiple Myeloma: Expert Review of New Data Presentations from ASH 2019

The number and type of therapeutic options available to treat patients with multiple myeloma has risen dramatically over recent years, offering exciting opportunities to significantly improve the future management of this currently incurable disease. Some of the latest advances in the settings of newly diagnosed and relapsed/refractory multiple myeloma were presented at the 61st Annual Meeting of the American Society of Hematology (Orlando, Florida, December 7 to 10, 2019) and are reviewed in this article with accompanying expert commentary. Presentations covered the use of registry-generated real-world data to define the characteristics of 'functional' high-risk patients in order to enable early therapeutic intervention for this poor-prognosis subset; studies that reported impressive new and updated data with novel combinations of targeted agents across different settings, including biomarker-specific subgroups; and promising early-phase data with novel immunotherapeutic approaches, such as bispecific antibodies and chimeric antigen receptor T-cell B-cell maturation antigen-directed therapies. This review offers insights into how these latest developments may fit within the rapidly evolving treatment landscape. The adoption and optimal use of novel therapies may be impacted by logistical challenges such as limited funding and access to necessary infrastructure to provide these treatments. In this manuscript, we focus particularly on Asia-Pacific regions and identify areas for development, such as establishment of robust national registries, promotion of investigator-initiated trials, compassionate-use treatment programs, and collaboration between jurisdictions with similar patterns of care. The hope is that such efforts will augment research outputs and ultimately translate into improved patient outcomes in the real world.

[The prognostic significance of dynamic monitoring of minimal residual disease (MRD) status in patients with newly-diagnosed multiple myeloma]

Objective: To evaluate the prognostic value of kinetic changes in minimal residual disease (MRD) status, as well as its relationship with risk stratification, therapeutic response and treatment in patients with newly-diagnosed multiple myeloma (MM) . Methods: A total of 135 patients with newly-diagnosed MM were screened, and 105 patients who achieved VGPR or more as the best responses were included into this study. The MRD status was determined by multiparameter flow cytometry (MFC) at multiple intervals after two cycles of treatment until clinical relapse, death, or last follow-up. The statistical methods included Kaplan-Meier analysis, Cox regression, etc. Results: ①In all 135 patients, 57.8% (78/135) patients achieved MRD negativity (MRD(-)) after treatment. In 105 patients who achieved VGPR and thus included in this study, the MRD(-) rate was 72.4% (76/105) , with a median interval of 3 months from starting treatment to achievement of MRD(-) status. ②The 2-year PFS rate of patients with MRD(-) status was significantly higher than that of MRD(+) status (62.2% vs 41.3%, P=0.001) , while MRD persistence (MRD(+)) was an independent factor for poor prognosis (multivariate analysis for PFS: P=0.044, HR=3.039, 95%CI 1.029-8.974) . ③Loss of MRD(-) status (i.e., MRD reappearance) showed inferior outcomes compared with MRD sustained negative ones, the PFS was 18 months versus not reach (P<0.001) and the OS was not reach for both (P=0.002) . ④The 2-year PFS and OS rates of patients with duration of MRD(-)status≥12 months were significantly higher than those of the control group (PFS: 77.7% vs 36.7%, P<0.001; OS: 96.4% vs 57.9%, P<0.001 respectively) . Duration of MRD(-) status was associated with a marked reduction in risk of relapse or death (univariate analysis for PFS: P<0.001, HR=0.865, 95%CI 0.815-0.918; for OS: P=0.001, HR=0.850, 95%CI 0.741-0.915 respectively) . ⑤Moreover, even in patients carrying high-risk cytogenetic abnormalities (CA) or ineligible for ASCT, MRD negativity remained its prognostic value to predict PFS (high-risk CA medianPFS: not reach vs 19 months, P=0.006; ineligible for ASCT medianPFS: not reach vs 25 months, P=0.052 respectively) . ⑥Last, treatment with the bortezomib-based regimens contributed to prolonged MRD(-) duration (median MRD(-) duratio: 25 months vs 10 months, P=0.034) . Conclusion: Our findings supported MRD(+) status as an independent poor prognostic factor in MM patients, which implicated that duration of MRD(-) status also played a significant role in evaluation of prognosis, while loss of MRD(-)status might serve as an early biomarker for relapse. Therefore, monitoring of MRD kinetics might more precisely predict prognosis, as well as guide treatment decision, especially for when to start retreatment in relapsed patients.

Minimal residual disease negativity and lenalidomide maintenance therapy are associated with superior survival outcomes in multiple myeloma

Modern combinations of therapies for multiple myeloma have led to improvement in survival outcomes with near 100% overall response rate and 25% complete response rates, particularly with autologous hematopoietic cell transplant (AHCT). Minimal residual disease (MRD) assessment with multiparameter flow cytometry is a valid prognostic biomarker for progression-free survival (PFS) and overall survival (OS). However, few data exist regarding whether MRD positivity or negativity will meaningfully influence treatment decisions. We evaluated 433 patients who received induction therapy, followed by AHCT. Participants had MRD assessment by multiparameter flow cytometry before and at days +100 and +365 following AHCT. They also received either lenalidomide, bortezomib, or no maintenance therapy following AHCT. Maintenance treatment with lenalidomide improved MRD negativity at day +365 compared to bortezomib (92.9% vs 41.6%, p = 0.01), or no maintenance therapy (92.9% vs 24.4%, p = 0.012). The median PFS for patients who were MRD negative at day + 365 was 42 vs 17.5 months (p < 0.001) and median OS was 80.6 vs 59 months (p = 0.02). Maintenance therapy following AHCT for multiple myeloma improves the depth of response as assessed by MRD.

Minimal Residual Disease in Multiple Myeloma: Current Landscape and Future Applications With Immunotherapeutic Approaches

The basic principle that deeper therapeutic responses lead to better clinical outcomes in cancer has emerged technologies capable of detecting rare residual tumor cells. The need for ultra-sensitive approaches for minimal residual disease (MRD) detection is particularly evident in Multiple Myeloma (MM), where patients will ultimately relapse despite the achievement of complete remission, which is commonplace due to remarkable therapeutic advances. Consequently, current response criteria on MM have been amended based on MRD status and MRD negativity is now considered the most dominant prognostic factor and the most valuable indicator for a subsequent relapse. However, there are particular limitations and several aspects for MRD assessment that remain open. This review summarizes current data on MRD in the clinical management of MM, highlights open issues and discusses the challenges and the endless opportunities arising for both patients and clinicians. Furthermore, it focuses on the current status of MRD in clinical trials, its dynamics in addressing debatable aspects in the clinical handling and its potential role as the prevailing factor for future MRD-driven tailored therapies.

Impact of minimal residual negativity using next generation flow cytometry on outcomes in light chain amyloidosis

We evaluated bone marrow minimal residual disease (MRD) negativity in 44 patients with light chain (AL) amyloidosis using next generation flow cytometry (sensitivity ≥1 × 10-5 ; median events analyzed: 8.7 million, range: 4.8 to 9.7 million). All patients underwent MRD testing in 2 years from start of therapy (median: 7 months). The overall MRD negative rate was 64% (n = 28). The MRD-negative rate after one-line of therapy was 71% (20/28). And, MRD negative rates were higher with stem-cell transplant as first-line therapy (86%, 18/21) vs chemotherapy alone as first-line treatment (29%, 2/7), P = .005. The MRD negative rate amongst patients in complete response was 75% (15/20), and in very good partial response, 50% (11/22). There were two patients in partial response/rising light chains (with renal dysfunction) who were MRD negative. There were no differences in baseline characteristics of MRD negative vs MRD positive patients, except younger age amongst MRD-negative patients. Patients with MRD negativity were more likely to have achieved cardiac response at the time of MRD assessment, 67% (8/12) vs 22% (2/7), P = .04. Renal response rates were similar in both groups. Progression free survival was assessed in the 42 patients achieving CR or VGPR. After median follow-up of 14 months, the estimated 1-year progression free survival in MRD negative vs MRD positive patients was 100% (26 patients, 0 events) vs 64% (16 patients, five events), P = .006, respectively. MRD assessment should be explored as a surrogate endpoint in clinical trials and MRD risk-adapted trials may help optimize treatment in AL amyloidosis.

Measurable Residual Disease by Next-Generation Flow Cytometry in Multiple Myeloma

PURPOSE

Assessing measurable residual disease (MRD) has become standard with many tumors, but the clinical meaning of MRD in multiple myeloma (MM) remains uncertain, particularly when assessed by next-generation flow (NGF) cytometry. Thus, we aimed to determine the applicability and sensitivity of the flow MRD-negative criterion defined by the International Myeloma Working Group (IMWG).

PATIENTS AND METHODS

In the PETHEMA/GEM2012MENOS65 trial, 458 patients with newly diagnosed MM had longitudinal assessment of MRD after six induction cycles with bortezomib, lenalidomide, and dexamethasone (VRD), autologous transplantation, and two consolidation courses with VRD. MRD was assessed in 1,100 bone marrow samples from 397 patients; the 61 patients without MRD data discontinued treatment during induction and were considered MRD positive for intent-to-treat analysis. The median limit of detection achieved by NGF was 2.9 × 10−6. Patients received maintenance (lenalidomide ± ixazomib) according to the companion PETHEMA/GEM2014MAIN trial.

RESULTS

Overall, 205 (45%) of 458 patients had undetectable MRD after consolidation, and only 14 of them (7%) have experienced progression thus far; seven of these 14 displayed extraosseous plasmacytomas at diagnosis and/or relapse. Using time-dependent analysis, patients with undetectable MRD had an 82% reduction in the risk of progression or death (hazard ratio, 0.18; 95% CI, 0.11 to 0.30; P < .001) and an 88% reduction in the risk of death (hazard ratio, 0.12; 95% CI, 0.05 to 0.29; P < .001). Timing of undetectable MRD (after induction v intensification) had no impact on patient survival. Attaining undetectable MRD overcame poor prognostic features at diagnosis, including high-risk cytogenetics. By contrast, patients with Revised International Staging System III status and positive MRD had dismal progression-free and overall survivals (median, 14 and 17 months, respectively). Maintenance increased the rate of undetectable MRD by 17%.

CONCLUSION

The IMWG flow MRD-negative response criterion is highly applicable and sensitive to evaluate treatment efficacy in MM.

Second malignancies in multiple myeloma; emerging patterns and future directions

The changing landscape of treatment options for multiple myeloma has led to a higher proportion of patients achieving deep, long-lasting responses to therapy. With the associated improvement in overall survival, the development of subsequent second malignancies has become of increased significance. The risk of second malignancy after multiple myeloma is affected by a combination of patient-, disease- and therapy-related risk factors. This review discusses recent data refining our knowledge of these contributing factors, including current treatment modalities which increase risk (i.e. high-dose melphalan with autologous stem cell transplant and lenalidomide maintenance therapy). We highlight emerging data towards individualized risk- and response-adapted treatment strategies and discuss key areas requiring future research.

CD27 antigen negative expression indicates poor prognosis in newly diagnosed multiple myeloma

To investigate the role of CD27 in multiple myeloma(MM), bone marrow samples from 165 newly diagnosed MM were analysed by flow cytometry. CD27- group (n = 93) had higher level of plasma cell proportion (37.00% vs 22.50%, p < .05), β2-MG (5.42 vs 3.20 mg/L, p < .05), calcium (2.45 vs 2.28 mmol/L, p < .05),higher percentage of ISS stage III (49.46% vs 22.22%, p < .05) and patients with ≥2 high-risk cytogenetics (24.73% vs 15.28%, p < .05) than CD27+ group (n = 72). After 4 cycles of chemotherapy, the overall response rate in CD27- group were lower than CD27+ group (56.67% vs 73.02%,p < .05). After a median follow-up of 18 months, progression-free survival was significantly shorter in CD27- group than in CD27+ group (22 vs 40 months, p < .05), so was overall survival (median OS not reached, p < .05). Gene sequencing showed more adverse mutations in CD27- group than CD27+ group.

Measurable disease evaluation in patients with myeloma

Recent years saw significant breakthroughs in treatment of multiple myeloma. Durable remissions are now seen in a significant proportion of patients with the previously uniformly incurable and progressive disease. Yet because of deep suppression of the neoplastic myeloma clones by the newer therapies, older disease monitoring techniques are insufficient to distinguish between the patients at high risk of imminent relapse and those in whom durable remission is expected. This review briefly describes prognostic and therapeutic implications of measurable disease (MRD) evaluation, explains why deep MRD evaluation is needed for patients without morphologic evidence of disease, and reviews the state of the art of evaluation of myeloma MRD by flow cytometry.

Clinical Applications and Future Directions of Minimal Residual Disease Testing in Multiple Myeloma

In the last years, the life expectancy of multiple myeloma (MM) patients has substantially improved thanks to the availability of many new drugs. Our ability to induce deep responses has improved as well, and the treatment goal in patients tolerating treatment moved from the delay of progression to the induction of the deepest possible response. As a result of these advances, a great scientific effort has been made to redefine response monitoring, resulting in the development and validation of high-sensitivity techniques to detect minimal residual disease (MRD). In 2016, the International Myeloma Working Group (IMWG) updated MM response categories defining MRD-negative responses both in the bone marrow (assessed by next-generation flow cytometry or next-generation sequencing) and outside the bone marrow. MRD is an important factor independently predicting prognosis during MM treatment. Moreover, using novel combination therapies, MRD-negative status can be achieved in a fairly high percentage of patients. However, many questions regarding the clinical use of MRD status remain unanswered. MRD monitoring can guide treatment intensity, although well-designed clinical trials are needed to demonstrate this potential. This mini-review will focus on currently available techniques and data on MRD testing and their potential future applications.

Minimal Residual Disease Negativity Does Not Overcome Poor Prognosis in High-Risk Multiple Myeloma: A Single-Center Retrospective Study

BACKGROUND

Minimal residual disease (MRD) is a standard measurement for response assessment in multiple myeloma (MM). Despite new treatments, high-risk MM patients continue to have poor prognosis. We evaluated the effect of MRD negativity in high-risk versus standard-risk patients.

PATIENTS AND METHODS

We retrospectively evaluated all consecutive MM patients who underwent routine MRD testing by 1-tube 8-color advanced flow cytometry with 2,000,000 events and sensitivity level 10^-5 at our center from 2015 to 2018 after initial therapy. Kaplan-Meier and log-rank test were used to assess survival estimates and differences between study groups.

RESULTS

One hundred thirty-six patients with MRD testing after initial therapy or autologous stem-cell transplantation were identified. At a median follow-up of 14 months (range, 1-36 months), progression-free survival and overall survival were significantly worse in high-risk versus standard-risk patients. During the study period, 50% of high-risk group had experienced disease progression (relapse and/or death) versus 20% in the standard-risk group (P = .0006). No patients with standard-risk died, but 4 (14%) in the high-risk group did (P = .0007). Regardless of MRD status, high-risk patients had statistically significant worse progression-free survival than standard-risk patients. At median follow-up, those with disease 10% standard-risk/MRD negative; 20% standard-risk/MRD positive; 40% high-risk/MRD negative; and 45% high-risk/MRD positive had either experienced relapse or died (P = .0041). MRD status did not significantly affect overall survival in either group (P = .0914); however, longer follow-up is needed to assess survival.

CONCLUSION

Genetic abnormalities remain a powerful prognostic indicator for MM, regardless of MRD status. For newly diagnosed MM patients treated with novel triple-drug initial therapy and frontline autologous stem-cell transplantation, MRD-negative status did not mitigate the poor-prognosis outcomes of high-risk MM patients.

Methodological considerations for the high sensitivity detection of multiple myeloma measurable residual disease

BACKGROUND

Recent advances in therapeutic interventions have dramatically improved complete response rates in patients with multiple myeloma (MM). The ability to identify residual myeloma cells (e.g., measurable residual disease [MRD]) can provide valuable information pertaining to patient's depth of response to therapy and risk of relapse. Multiparametric flow cytometry is an excellent technique to monitor MRD and has been demonstrated to correlate with patient outcome post-treatment. To achieve the high sensitivity (one abnormal cell in 10⁵ -10⁶ cells) required for MRD evaluation, millions of cells have to be acquired and conventional immunophenotyping protocols are unable to attain these numbers, indicating the needs for alternative flow cytometric staining procedures. A bulk, "Pre-lysis" method is the consensus approach for staining large number of cells, requires two red blood cell lysis steps, and can adversely affect epitope density. In this study, we tested the "Pooled-tube" and "Dextran Sedimentation" staining procedures and correlated them with the "Pre-lysis" method as potential alternative approaches.

METHODS

A total of 22 bone marrow aspirates from patients with plasma cell (PC) dyscrasia were processed in parallel using the "Pre-lysis," "Pooled-tube," and "Dextran Sedimentation" techniques. Stain indices were calculated and compared to assess their impacts on staining performance for each antibody used in the consensus panel. The recovery of normal and abnormal PCs, mast cells, and B cell precursors was enumerated and compared after their counts were normalized using fluorescent beads. The limit of blank, limit of detection, and lower limit of quantification were established using serial dilution experiments.

RESULTS

The staining performances of CD19 PECy7, CD27 BV510, CD81 APCH7, and CD138 BV421 were improved using the "Pooled-tube" method when compared to "Pre-lysis." "Pre-lysis" was better at resolving CD56 using clone C5.9 but our results demonstrated similar improvement can also be achieved by "Pooled-tube" when alternative CD56 PE clones were used. "Dextran sedimentation" yielded similar staining results when compared to "Pre-lysis" for all the markers analyzed. The "Pooled-tube" method, when normalized to "Pre-lysis," recovered higher numbers of total PCs (1.2 ± 0.2 times higher; p = .049), normal PCs (1.4 ± 0.26; p = .007), mast cells (1.46 ± 0.27; p = .003), and B cell precursors (1.42 ± 0.3; p = .011), but not abnormal PCs (1.09 ± 0.2; p = .352). There was no evidence that the recovery of cells was different between "Pre-lysis" versus "Dextran Sedimentation." All three flow cytometric assays achieved a minimum sensitivity of 10^-5 and approached that of 10^-6 for detecting rare events.

CONCLUSION

Both "Pooled-tube" and "Dextran Sedimentation" staining procedures were comparable to the "Pre-lysis" method and are suitable high sensitivity flow cytometric approaches that can be used to process bone marrow samples for MM MRD testing.

Therapeutic Monoclonal Antibodies and Antibody Products: Current Practices and Development in Multiple Myeloma

Immunotherapy is the latest innovation for the treatment of multiple myeloma (MM). Monoclonal antibodies (mAbs) entered the clinical practice and are under evaluation in clinical trials. MAbs can target highly selective and specific antigens on the cell surface of MM cells causing cell death (CD38 and CS1), convey specific cytotoxic drugs (antibody-drug conjugates), remove the breaks of the immune system (programmed death 1 (PD-1) and PD-ligand 1/2 (L1/L2) axis), or boost it against myeloma cells (bi-specific mAbs and T cell engagers). Two mAbs have been approved for the treatment of MM: the anti-CD38 daratumumab for newly-diagnosed and relapsed/refractory patients and the anti-CS1 elotuzumab in the relapse setting. These compounds are under investigation in clinical trials to explore their synergy with other anti-MM regimens, both in the front-line and relapse settings. Other antibodies targeting various antigens are under evaluation. B cell maturation antigens (BCMAs), selectively expressed on plasma cells, emerged as a promising target and several compounds targeting it have been developed. Encouraging results have been reported with antibody drug conjugates (e.g., GSK2857916) and bispecific T cell engagers (BiTEs^®), including AMG420, which re-directs T cell-mediated cytotoxicity against MM cells. Here, we present an overview on mAbs currently approved for the treatment of MM and promising compounds under investigation.

Pursuing a Curative Approach in Multiple Myeloma: A Review of New Therapeutic Strategies

Multiple myeloma (MM) is still considered an incurable hematologic cancer and, in the last decades, the treatment goal has been to obtain a long-lasting disease control. However, the recent availability of new effective drugs has led to unprecedented high-quality responses and prolonged progression-free survival and overall survival. The improvement of response rates has prompted the development of new, very sensitive methods to measure residual disease, even when monoclonal components become undetectable in patients' serum and urine. Several scientific efforts have been made to develop reliable and validated techniques to measure minimal residual disease (MRD), both within and outside the bone marrow. With the newest multidrug combinations, a good proportion of MM patients can achieve MRD negativity. Long-lasting MRD negativity may prove to be a marker of "operational cure", although the follow-up of the currently ongoing studies is still too short to draw conclusions. In this article, we focus on results obtained with new-generation multidrug combinations in the treatment of high-risk smoldering MM and newly diagnosed MM, including the potential role of MRD and MRD-driven treatment strategies in clinical trials, in order to optimize and individualize treatment.

Evidence-Based Minireview: Does achieving MRD negativity after initial therapy improve prognosis for high-risk myeloma patients?

You are evaluating a 47-year-old man with revised international staging system stage III myeloma who recently underwent an autologous stem cell transplant after receiving 6 cycles of carfilzomib, lenalidomide, and dexamethasone for newly diagnosed disease. Fluorescence in situ hybridization testing at initial presentation also revealed t(4;14). On day 100 evaluation after transplant, he has achieved a stringent complete response. Two-tube, 8-color advanced flow cytometry with a sensitivity of 10-5 shows no minimal residual disease. Whole-body positron emission tomography/computed tomography scan shows resolution of all fluorodeoxyglucose avid uptake seen at diagnosis. The patient asks you how these test results impact his prognosis and whether this overcomes his baseline high risk from t(4;14)?

Response-adapted intensification with cyclophosphamide, bortezomib, and dexamethasone versus no intensification in patients with newly diagnosed multiple myeloma (Myeloma XI): a multicentre, open-label, randomised, phase 3 trial

BACKGROUND

Multiple myeloma has been shown to have substantial clonal heterogeneity, suggesting that agents with different mechanisms of action might be required to induce deep responses and improve outcomes. Such agents could be given in combination or in sequence on the basis of previous response. We aimed to assess the clinical value of maximising responses by using therapeutic agents with different modes of action, the use of which is directed by the response to the initial combination therapy. We aimed to assess response-adapted intensification treatment with cyclophosphamide, bortezomib, and dexamethasone (CVD) versus no intensification treatment in patients with newly diagnosed multiple myeloma who had a suboptimal response to initial immunomodulatory triplet treatment which was standard of care in the UK at the time of trial design.

METHODS

The Myeloma XI trial was an open-label, randomised, phase 3, adaptive design trial done at 110 National Health Service hospitals in the UK. There were three potential randomisations in the study: induction treatment, intensification treatment, and maintenance treatment. Here, we report the results of the randomisation to intensification treatment. Eligible patients were aged 18 years or older and had symptomatic or non-secretory, newly diagnosed multiple myeloma, had completed their assigned induction therapy as per protocol (cyclophosphamide, thalidomide, and dexamethasone or cyclophosphamide, lenalidomide, and dexamethasone) and achieved a partial or minimal response. For the intensification treatment, patients were randomly assigned (1:1) to cyclophosphamide (500 mg daily orally on days 1, 8, and 15), bortezomib (1·3 mg/m2 subcutaneously or intravenously on days 1, 4, 8, and 11), and dexamethasone (20 mg daily orally on days 1, 2, 4, 5, 8, 9, 11, and 12) up to a maximum of eight cycles of 21 days or no treatment. Patients were stratified by allocated induction treatment, response to induction treatment, and centre. The co-primary endpoints were progression-free survival and overall survival, assessed from intensification randomisation to data cutoff, analysed by intention to treat. Safety analysis was per protocol. This study is registered with the ISRCTN registry, number ISRCTN49407852, and clinicaltrialsregister.eu, number 2009-010956-93, and has completed recruitment.

FINDINGS

Between Nov 15, 2010, and July 28, 2016, 583 patients were enrolled to the intensification randomisation, representing 48% of the 1217 patients who achieved partial or minimal response after initial induction therapy. 289 patients were assigned to CVD treatment and 294 patients to no treatment. After a median follow-up of 29·7 months (IQR 17·0-43·5), median progression-free survival was 30 months (95% CI 25-36) with CVD and 20 months (15-28) with no CVD (hazard ratio [HR] 0·60, 95% CI 0·48-0·75, p<0·0001), and 3-year overall survival was 77·3% (95% Cl 71·0-83·5) in the CVD group and 78·5% (72·3-84·6) in the no CVD group (HR 0·98, 95% CI 0·67-1·43, p=0·93). The most common grade 3 or 4 adverse events for patients taking CVD were haematological, including neutropenia (18 [7%] patients), thrombocytopenia (19 [7%] patients), and anaemia (8 [3%] patients). No deaths in the CVD group were deemed treatment related.

INTERPRETATION

Intensification treatment with CVD significantly improved progression-free survival in patients with newly diagnosed multiple myeloma and a suboptimal response to immunomodulatory induction therapy compared with no intensification treatment, but did not improve overall survival. The manageable safety profile of this combination and the encouraging results support further investigation of response-adapted approaches in this setting. The substantial number of patients not entering this trial randomisation following induction therapy, however, might support the use of combination therapies upfront to maximise response and improve outcomes as is now the standard of care in the UK.

FUNDING

Cancer Research UK, Celgene, Amgen, Merck, Myeloma UK.

[Clinical implication of minimal residual disease monitoring by 10-color flow cytometry in multiple myeloma]

目的

采用十色流式细胞术监测多发性骨髓瘤（MM）患者治疗后骨髓微小残留病（MRD），探讨其对MM患者预后的预测价值。

方法

回顾性分析2015年7月至2017年7月苏州大学附属第一医院收治的150例MM患者的临床资料，十色流式细胞术检测MRD水平。

结果

①诱导治疗结束后采用十色流式细胞术监测MRD的87例MM患者中，MRD阴性者34例（39.1%）。自体造血干细胞移植后1年内行十色流式细胞术监测MRD的69例患者中，MRD阴性者34例（49.3%），诱导治疗结束和移植后MRD阴性患者的无进展生存（PFS）期优于MRD阳性患者（未达到对21个月，P=0.022；未达到对18个月，P<0.001）。②根据移植前后MRD的动态改变将MM患者分为MRD持续阴性、阳性转阴性、持续阳性、阴性转阳性四组，四组的2年PFS率分别为83%、82%、44%、0（P=0.002）。③多因素分析显示诱导治疗结束后的MRD水平是影响PFS的独立预后因素[P=0.002，HR=4.808（95%CI 1.818~12.718）]。

结论

治疗后MRD转阴提示更好的临床预后，MRD水平对于MM患者的预后价值优于血清学疗效评估，可以联合R-ISS分期及细胞遗传学异常评估患者预后。

Minimal Residual Disease Status as a Surrogate Endpoint for Progression-free Survival in Newly Diagnosed Multiple Myeloma Studies: A Meta-analysis

BACKGROUND

Therapeutic advances have greatly extended survival times in patients with multiple myeloma, necessitating increasingly lengthy trials when using survival outcomes as primary endpoints. A surrogate endpoint that can more rapidly predict survival could accelerate drug development. We conducted a meta-analysis to evaluate minimal residual disease (MRD) status as a valid progression-free survival (PFS) surrogate in patients with newly diagnosed multiple myeloma (NDMM).

MATERIALS AND METHODS

We searched abstracts in PubMed, The American Society of Hematology, and the European Hematology Association for "myeloma," "minimal residual disease," and "clinical trial." Because of the need to evaluate the treatment effect on MRD response, only randomized studies for subjects with NDMM were included. Details on the MRD-tested populations were required. The meta-analysis was performed by principles outlined at the 2013 United States Food and Drug Administration workshop on MRD in acute myeloid leukemia.⁴² For samples that were not measured for MRD and within the subset specified for MRD assessment, their MRD status was imputed from the samples that had known MRD status. Patients that were excluded from planned MRD assessment were considered MRD-positive.

RESULTS

Six randomized studies, representing 3283 patients and 2208 MRD samples, met analysis inclusion criteria. MRD negativity rates ranged from 0.06 to 0.70. The treatment effect on the odds ratio for MRD-negative response strongly correlated with the hazard ratio for PFS with a coefficient of determination for the weighted regression line of 0.97. Our meta-analysis suggested that MRD status met both the Prentice criteria for PFS surrogacy.

CONCLUSIONS

These results support the claim that MRD status can be used as a surrogate for PFS in NDMM.

Monitoring the cytogenetic architecture of minimal residual plasma cells indicates therapy-induced clonal selection in multiple myeloma

Recent attempts have focused on identifying fewer magnitude of minimal residual disease (MRD) rather than exploring the biological and genetic features of the residual plasma cells (PCs). Here, a cohort of 193 patients with at least one cytogenetic abnormalities (CA) at diagnosis were analyzed, and interphase fluorescence in situ hybridization (iFISH) analyses were performed in patient-paired diagnostic and posttherapy samples. Persistent CA in residual PCs were observed for the majority of patients (63%), even detectable in 28/63 (44%) patients with MRD negativity (<10^-4). The absence of CA in residual PCs was associated with prolonged survival regardless of MRD status. According to the change of the clonal size of specific CA, patients were clustered into five groups, reflecting different patterns of clone selection under therapy pressure. Therapy-induced clonal selection exerted a significant impact on survival (HR = 4.0; P < 0.001). According to the longitudinal cytogenetic studies at relapse, sequential cytogenetic dynamics were observed in most patients, and cytogenetic architecture of residual PCs could to some extent predict the evolutional pattern at relapse. Collectively, the repeat cytogenetic evaluation in residual PCs could not only serves as a good complementary tool for MRD detection, but also provides a better understanding of clinical response and clonal evolution.