Thalidomide before and after autologous stem cell transplantation in recently diagnosed multiple myeloma (HOVON-50): long-term results from the phase 3, randomised controlled trial

Validity of Patient-Reported Outcome Measures in Evaluating Nerve Damage Following Chemotherapy

Importance

Chemotherapy-induced peripheral neuropathy (CIPN) is a substantial adverse effect of anticancer treatments. As such, the assessment of CIPN remains critically important in both research and clinic settings.

Objective

To compare the validity of various patient-reported outcome measures (PROMs) with neurophysiological and sensory functional measures as the optimal method of CIPN assessment.

Design, Setting, and Participants

This cohort study evaluated participants treated with neurotoxic chemotherapy across 2 cohorts using a dual-study design. Participants commencing treatment were assessed prospectively at beginning of neurotoxic treatment, midtreatment, and at the end of treatment. Participants who completed treatment up to 5 years prior were assessed cross-sectionally and completed a single assessment time point. Participants were recruited from oncology centers in Australia from August 2015 to November 2022. Data analysis occurred from February to November 2023.

Exposures

Neurotoxic cancer treatment including taxanes, platinums, vinca-alkaloids, proteasome inhibitors, and thalidomide.

Main Outcomes and Measures

CIPN was assessed via PROMs (European Organization for Research and Treatment of Cancer Quality of Life Questionnaire [EORTC-CIPN20], Functional Assessment of Cancer Therapy/Gynecological Cancer Group Neurotoxicity Questionnaire (FACT/GOG-Ntx), and the patient-reported outcomes version of the Common Terminology Criteria for Adverse Events [PRO-CTCAE]), neurological and neurophysiological assessment (Total Neuropathy Score and sural and tibial compound nerve amplitudes), and sensory measures (Grating orientation, Von Frey monofilament, and 2-point discrimination tasks). Core measurement properties of CIPN outcome measures were evaluated. Convergent and known-groups validity was assessed cross-sectionally following treatment completion, and responsiveness was evaluated prospectively during treatment. Neurological, neurophysiological, and sensory outcome measure scores were compared between those who reported high and low levels of CIPN symptoms using linear regressions.

Results

A total of 1033 participants (median [IQR] age, 61 [50-59] years; 676 female [65.4%]) were recruited to this study, incorporating 1623 assessments. PROMs demonstrated best ability to accurately assess CIPN (convergent validity), especially the PRO-CTCAE composite score (r = 0.85; P < .001) and EORTC-CIPN20 (r = 0.79; P < .001). PROMS also demonstrated the best ability to discriminate between CIPN severity (known-groups validity) and to detect changes at onset of CIPN development (responsiveness), especially for EORTC-CIPN20 (d = 0.67; 95% CI, 0.52-0.83), FACT/GOG-Ntx (d = 0.65; 95% CI, 0.49-0.81) and the PRO-CTCAE (d = 0.83; 95% CI, 0.64-1.02). Other measures did not achieve threshold for convergent validity (α < 0.7). Neurophysiological and sensory measures did not demonstrate acceptable responsiveness. In regression models, neurological, neurophysiological, and sensory outcome measures were significantly impaired in participants who reported high levels of CIPN symptoms compared with those who reported low levels of CIPN symptoms.

Conclusions and Relevance

In this cohort study of 1033 cancer patients, PROMs were the only measures to satisfy all 3 core measurement property criteria (convergent validity, known-groups validity, and responsiveness). These findings suggest that adoption of PROMs in clinical practice can equip clinicians with valuable information in assessing CIPN morbidity.

Efficacy and safety of thalidomide in gastrointestinal angiodysplasias: systematic review and meta-analysis with trial sequential analysis of randomized controlled trials

Background

Gastrointestinal (GI) angiodysplasias is a potential cause of life-threatening bleeding. Thalidomide may have a certain effect on the treatment.

Objectives

We aim to evaluate the efficacy and safety of thalidomide and used trial sequential analysis (TSA) to assess the need for further randomized controlled trials (RCTs).

Design

Meta-analysis of RCTs.

Data sources and methods

We systematically searched Cochrane Central Register of Controlled Trials (CENTRAL), Medical Literature Analysis and Retrieval System Online (MEDLINE), Embase, WanFang, and China National Knowledge Infrastructure databases for RCTs evaluating thalidomide in GI angiodysplasias without language restrictions. We used a random-effects model to obtain pool data and followed Grading of Recommendations Assessment, Development and Evaluation framework. TSA was employed to control the risk of random errors and to evaluate the validity of our conclusions.

Results

Three RCTs were included involving 279 patients with the proportion of small intestinal angiodysplasias of 87.1%. Thalidomide led to improved mean change of hemoglobin level [mean difference (MD): 3.06, 95% confidence interval: 2.66-3.46] without severe adverse effects occurring. Other secondary endpoints, including effective response rate, cessation of bleeding after treatment, hospitalization rate because of bleeding, change in duration of hospital stays for bleeding, transfused red cell requirements, and overall adverse effects, also showed significantly better outcomes in the thalidomide group compared to the control group. TSA for all outcomes exceeded required information sizes, and cumulative Z curve all traverse trial sequential monitoring boundary.

Conclusion

Almost all of the evidence was of moderate quality, suggesting that thalidomide holds promise for treating GI angiodysplasias, with favorable safety profiles. TSA suggests that conducting large-scale real-world research is recommended over relying solely on RCTs conducted within the same population and trial design.

Trial registration

This meta-analysis protocol was registered on PROSPERO (CRD42023480621).

The role of maintenance therapy following autologous stem cell transplantation in newly diagnosed multiple myeloma: Considerations on behalf of the Chronic Malignancies Working Party of the EBMT

Recent treatment advancements in multiple myeloma have led to significant improvements in patient outcomes. Maintenance therapy following autologous haematopoietic stem cell transplantation (AHCT) is now standard of care and has been demonstrated to prolong and deepen treatment responses. Currently, lenalidomide remains the single agent that has been approved for maintenance post-AHCT in Europe and the USA which, if tolerated, is continued until disease progression. The treatment landscape is rapidly expanding however, and the optimal personalised maintenance approach for a patient is becoming more complex. Treatment outcomes for patients with high-risk disease remain poor and choice of maintenance in this population also remains unclear. This review article evaluates up-to-date literature regarding established maintenance approaches. It further analyses ongoing studies exploring maintenance regimens using combination and novel agents, approaches to maintenance in patients with cytogenetic high-risk disease and minimal residual disease response-adapted strategies that reflect the current evolving treatment paradigm.

Newly diagnosed multiple myeloma: making sense of the menu

The development of new drugs and subsequent novel combinations for the treatment of newly diagnosed multiple myeloma (NDMM) has resulted in a plethora of treatment options that can make the choice of initial induction therapy a challenge. A greater understanding of both patient- and disease-specific factors can provide a personalized approach to help design a treatment course. Historically, the choice of an induction regimen has been tethered to an initial impression of transplant eligibility at the time of diagnosis. As more effective and better-tolerated induction regimens have emerged, there has been increasing overlap in the induction strategies used for all patients with NDMM, which increasingly provide the ultimate goal of deep and durable remissions. The current treatment options and strategies for the management of NDMM are evaluated using the best available data to provide a rationale for these decisions.

Efficacy of maintenance treatment in patients with multiple myeloma: a systematic review and network meta-analysis

BACKGROUND

Despite conspicuous advances in innovating novel drugs and combination regimens in multiple myeloma (MM) in recent decades, the most appropriate maintenance regimens after inductive therapy are still controversial and opaque.

OBJECTIVE

We aimed to identify the most effective maintenance treatment for newly diagnosed multiple myeloma (NDMM) patients via network meta-analysis.

METHOD

We searched PubMed, Embase, Cochrane Library, Scopus, and Google Scholars from inception to April, 2022. Odds ratios (ORs) were generated for dichotomous variants. The primary endpoint was overall survival (OS).

RESULTS

Eventually a total of 19 trials, including 11 treatments and 8337 patients, were included in this analysis. For OS, lenalidomide (OR ranged from 1.61 to 1.99) and daratumumab (OR ranged from 1.83 to 2.41) showed significant efficacy over placebo. Maintenance therapy comprising lenalidomide-carfilzomib (OR ranged from 3.19 to 6.95), lenalidomide-prednisone (OR ranged from 2.62 to 4.44), bortezomib-thalidomide (OR ranged from 2.48 to 3.64), daratumumab (OR ranged from 2.0 to 2.98), lenalidomide (OR ranged from 1.4 to 3.19), ixazomib (OR ranged from 1.36 to 2.05), thalidomide (OR ranged from 1.5 to 1.86) demonstrated significant effects in prolonging PFS compared with placebo; Among the efficient therapies, lenalidomide-carfilzomib was significantly superior to lenalidomide (OR ranged from 2.18 to 2.20), daratumumab (OR ranged from 1.49 to 2.66) and ixazomib (OR ranged from 2.75 to 3.57).

CONCLUSION

Considering OS and PFS, lenalidomide-carfilzomib should be recommended as the best therapy. In clinical practice, this must be weighed against the increased risk of adverse events and financial burden. However, more head-to-head studies are needed to confirm these findings.

Impact of maintenance therapy post autologous stem cell transplantation for multiple myeloma in early and delayed transplant

Based on phase 3 trials, maintenance therapy after autologous stem cell transplantation (ASCT) has become the standard of care in multiple myeloma (MM). We examined the trends in maintenance therapy in a large group of patients (2530) transplanted at a single institution over two decades. Majority (n = 1958; 77%) had an ASCT within 12 months of diagnosis (early ASCT). Maintenance was employed in 39% of the patients; 42% among early ASCT and 30.5% among delayed ASCT. Most common maintenance approach was an IMiD (61%), followed by a PI (31%), or a PI + IMiD (4%). Patients with high-risk FISH received PI-based maintenance more frequently. The PFS was superior with maintenance (36 vs. 22 months, p < 0.001); 37 vs. 25 months for early ASCT (p < 0.001) and 29 vs. 17 months for delayed ASCT (p = 0.0008). OS from ASCT was higher with maintenance for the whole cohort at 93 vs. 73 months (p < 0.001). OS from diagnosis was also better for the whole cohort with maintenance therapy, 112 vs. 93 months (p < 0.001). The improvement in PFS and OS was seen in high-risk and standard risk disease. The experience with maintenance therapy post ASCT for myeloma in a non-clinical trial setting confirms the findings from the phase 3 trials.

A review on the treatment of multiple myeloma with small molecular agents in the past five years

Multiple myeloma is currently incurable, and the incidence rate is increasing year by year worldwide. Although in recent years the combined treatment plan based on proteasome inhibitors and immunomodulatory drugs has greatly improved the treatment effect of multiple myeloma, most patients still relapse and become resistant to current treatments. To solve this problem, scientists are committed to developing drugs with higher specificity, such as iberdomide, which is highly specific to ikaros and aiolos. This review aims to focus on the small molecular agents that are being researched/clinically used for the treatment of multiple myeloma, including the target mechanism, structure-activity relationship and application prospects of small molecular agents.

Rapid Progress in the Use of Immunomodulatory Drugs and Cereblon E3 Ligase Modulators in the Treatment of Multiple Myeloma

Over the past two decades, the improvement in our understanding of the biology of MM and the introduction of new drug classes, including immunomodulatory drugs (IMiDs), proteasome inhibitors (PI), and monoclonal antibodies (MoAb), have significantly improved outcomes. The first IMiD introduced to treat MM was thalidomide. The side effects observed during treatment with thalidomide initiated work on the synthesis of IMiD analogs. Subsequently, lenalidomide and pomalidomide were developed, both with different safety profiles, and they have better tolerability than thalidomide. In 2010, the cereblon (CRBN) protein was discovered as a direct target of IMiDs. By binding to CRBN, IMiDs change the substrate specificity of the CRBN E3 ubiquitin ligase complex, which results in the breakdown of internal Ikaros and Aiolos proteins. Most clinical trials conducted, both in newly diagnosed, post-transplant maintenance and relapsed/refractory MM, report a beneficial effect of IMiDs on the extension of progression-free survival and overall survival in patients with MM. Due to side effects, thalidomide is used less frequently. Currently, lenalidomide is used at every phase of MM treatment. Lenalidomide is used in conjunction with other agents such as PIs and MoAb as induction and relapsed therapy. Pomalidomide is currently used to treat relapsed/refractory MM, also with PIs and monoclonal antibodies. Current clinical trials are evaluating the efficacy of IMiD derivatives, the CRBN E3 ligase modulators (CELMoDs). This review focuses on the impact of IMiDs for the treatment of MM.

Chemotherapy and peripheral neuropathy

Chemotherapy-induced peripheral neurotoxicity (CIPN) is a major dose-limiting side effect of many anti-cancer agents, including taxanes, platinums, vinca alkaloids, proteasome inhibitors, immunomodulatory drugs, and antibody-drug conjugates. The resultant symptoms often persist post treatment completion and continue to impact on long-term function and quality of life for cancer survivors. At present, dose reduction remains the only strategy to prevent severe neuropathy, often leading clinicians to the difficult decision of balancing maximal treatment exposure and minimal long-lasting side effects. This review examines the clinical presentations of CIPN with each class of neurotoxic treatment, describing signs, symptoms, and long-term outcomes. We provide an update on the proposed mechanisms of nerve damage and review current data on clinical and genetic risk factors contributing to CIPN development. We also examine recent areas of research in the treatment and prevention of CIPN, with specific focus on current clinical trials and consensus recommendations for CIPN management.

Limited benefits of thalidomide and dexamethasone maintenance after autologous stem cell transplantation in newly diagnosed multiple myeloma patients: a prospective phase II multi-center study in Korea

Although the clinical outcome of newly diagnosed multiple myeloma has improved with maintenance therapy, maintenance with novel agents is not always available depending on medical expenses or drug accessibility. We intended to investigate the efficacy and toxicity of thalidomide/dexamethasone maintenance in Korean patients. In this multicenter phase 2 study, patients with newly diagnosed myeloma who underwent induction chemotherapy followed by autologous stem cell transplantation (ASCT) were enrolled to receive maintenance treatment of 100mg thalidomide daily for 28 days and 40mg dexamethasone daily for 4 days each cycle. Maintenance was given up to 12 cycles. The primary endpoint was a 1-year event free survival (EFS) rate. It was assumed that EFS at 1-year would be 91% with thalidomide and 1-year EFS below 82% would be of no effect. A total of 43 patients were consecutively enrolled (median age, 58 years [range, 34 - 65]; male, n = 31). With a median follow-up duration of 17.3 months (range, 1.1 - 32.2), EFS at 1 year was 65.1% (95% confidence interval [CI], 48.9 - 77.3). PFS and OS at 1 year was 85.6% (95% CI, 70.7 - 93.3) and 90.4 (95% CI, 76.3 - 96.3), respectively. In terms of side effects, 39 patients (90.7%) experienced adverse events (AEs) of any grade, and 14 patients (32.6%) experienced grade 3 or 4 adverse events. 15 patients (34.9%) failed to complete 12 cycles of maintenance, and the most common reason for premature termination was AEs (n = 6). In Korean patients the benefits of thalidomide maintenance does not seem to outweigh the toxicity of thalidomide, especially in high-risk MM. Considering the long clinical course of MM, preservation of quality of life and finances might be more beneficial for subsequent MM treatment.

Safety of lenalidomide for maintenance treatment of patients with multiple myeloma following autologous stem cell transplantation

INTRODUCTION

Myeloma is the second most common hematological cancer, with 5800 cases per year diagnosed in the UK. Despite improved treatment it is still considered non-curable, although the median survival has increased from 3 to 8 years over the past 20 years. Treatment involves the use of induction therapy and consolidation with autologous stem cell transplant (ASCT) in patients deemed fit enough. Further attempts to improve outcomes include the use of maintenance therapy.

AREAS COVERED

This review details all trials in which lenalidomide has been used as maintenance following ASCT. PubMed searches included randomized control trials, observational cohort, reviews, and meta-analysis.

EXPERT OPINION

Lenalidomide is a well-tolerated, oral agent that is associated with increased overall and progression free survival when used as maintenance following ASCT. Its use in this setting is FDA and EMA approved and is standard of care in Europe and North America. The early link between lenalidomide and second hematological cancers appears to be associated with use in combination with melphalan. There is an increase in non-melanoma skin cancers and solid tumors in the elderly but this has minimal impact on mortality. Lenalidomide use as part of combination maintenance is underway and may further improve outcomes.

Post-Transplant Maintenance Treatment Options in Multiple Myeloma

Maintenance therapy post autologous stem cell transplant (ASCT) is commonly employed in myeloma patients to prolong remission, as relapse invariably occurs after ASCT. After initial diagnosis and risk stratification, patients receive initial therapy with a combination of drugs, typically a proteasome inhibitor and an immunomodulatory imide drug (IMiD), and in those considered eligible, high-dose chemotherapy followed by autologous stem cell transplant. The aim of our study was to review the literature and consolidate evidence regarding different maintenance therapies post stem cell transplant in myeloma patients. We reviewed major databases including PubMed, Cochrane Library and Evidence-Based Medicine Reviews (EBMR), along with American Society of Hematology/American Society of Clinical Oncology (ASH/ASCO) conference abstracts to include relevant literature. Ongoing clinical trials were also reviewed. Consolidation therapy is often employed to enhance the response to induction therapy and SCT and also to delay progression. Melphalan and thalidomide with or without steroids were initially used as maintenance therapy. More recently, lenalidomide-, bortezomib-, ixazomib-, or carfilzomib-based regimens have been employed as maintenance. Lenalidomide and bortezomib are the most commonly used drugs, with the latter being preferred in high-risk populations. Newer trials are utilizing tumor-specific antigen based vaccines along with adoptive T-cell therapies, and monoclonal antibodies as maintenance therapy. We conclude that maintenance therapy post SCT, with lenalidomide or bortezomib is the standard of care in myeloma patients. Patient tolerability, disease risk stratification and prior therapy received are major determinants of the choice of maintenance. Significant toxicity associated with maintenance therapies is a hindrance to long-term maintenance post stem cell transplant.

Renal insufficiency in multiple myeloma: a systematic review and meta-analysis of all randomized trials from 2005-2019

Clinical trials may be inconsistent in their enrollment and reporting of patients with multiple myeloma (MM) who have renal insufficiency (RI). We performed a systematic review of all MM randomized clinical trials (RCT) from 2005-2019 to evaluate reporting of prevalence, eligibility criteria and outcomes of patients with RI and MM. One-hundred and twenty-three RCTs were included. Only 30% of studies clearly reported on the proportion of patients who had RI. Only 68.2% reported eligibility criteria pertaining to RI, with no uniformity in the reported criteria. The relative risk (RR) of disease progression or death in patients with RI was higher than those without, RR of 1.20 (1.003-1.431) for relapsed/refractory and 1.07 (1.001-1.046) for newly diagnosed. There is inconsistent reporting and enrollment of patients with RI on MM RCT's. We advocate for higher enrollment of patients with RI and transparent reporting of their eligibility criteria and outcomes.

Advances in maintenance strategy in newly diagnosed multiple myeloma patients eligible for autologous transplantation

INTRODUCTION

Multiple myeloma (MM) lacks curative therapy. Therefore, researchers continue to conduct studies in an effort to improve progression-free survival (PFS) and overall survival (OS). Maintenance therapy (MT) after autologous stem cell transplant (ASCT) was extensively studied in the last decade and now considered a standard approach.

AREAS COVERED

This review evaluated the evidence and updates on various maintenance agents in newly diagnosed multiple myeloma (NDMM) after ASCT. Articles were searched on PubMed and Embase that were published in last 10 years. Both clinical trials and observational studies were evaluated.

EXPERT OPINION

Maintenance strategy after ASCT has consistent PFS benefit but lacks conclusive OS improvement. Lenalidomide is superior to thalidomide given reduced neurotoxicity. OS advantage is controversial for both due to inconsistent evidence. Lenalidomide may confer a PFS advantage even at lower doses due to toxicity with higher doses. Bortezomib-based maintenance has some evidence for OS benefit in high-risk MM (HRMM) and renal dysfunction. Ixazomib has preliminary promising results. Two or three drug combinations for MT are potentially safe and more effective, particularly in HRMM although data on this subject is still evolving. Efficacy of various MT regimens in terms of minimal residual disease status needs to be further investigated.

Chronic aspects of leprosy-neglected but important

The chronic aspects of leprosy are discussed here. They are a consequence of the peripheral nerve damage that affects many patients during their lifetime with leprosy. The peripheral nerve damage leaves people unable to feel and with weakness in their hands and feet. They are at risk of damaging their hands and feet, causing the disabilities and deformities that characterise late leprosy. More than 200 000 new leprosy patients are diagnosed globally each year. Better data are needed from cohort studies to estimate the number of patients developing nerve damage and modelling studies are needed to estimate the number of patients who develop disabilities. For some of them, this will be a lifelong disability. Nerve damage is caused by inflammation in leprosy-affected nerves. Patients with nerve damage of <6-mo duration need treatment with steroids. About 66% of multibacillary patients will develop nerve damage. Plastic graded monofilaments can be used to detect nerve damage in leprosy and diabetic clinics. Assessing nerve damage and treating patients with steroids in leprosy programmes needs to be strengthened. The World Health Organization has a successful programme for supplying antibiotics for treating leprosy infection to national leprosy programmes. They should take responsibility for providing steroids to national programmes since this is a core part of the treatment for >66% of multibacillary patients. Patients need to be asked about neuropathic pain symptoms and treated if necessary. Treated leprosy patients are at risk of developing ulcers in their feet. Treatment and prevention needs to be improved through health education, providing protective footwear and patient empowerment.

Newly Diagnosed Myeloma in 2020

Over the last few years, there has been great progress in the treatment of multiple myeloma (MM), with many new agents and combinations having been approved and being now routinely incorporated into treatment strategies for newly diagnosed patients. As a result, patients are experiencing benefits in terms of survival and better tolerance. However, the multitude of treatment options also presents a challenge to select the best options tailored to the specific patient situation. Frontline autologous stem cell transplantation (ASCT) is the standard of care for fit patients younger than age 71 who are newly diagnosed with MM, and triplet combinations are the backbone of induction therapy before ASCT. Post-transplant consolidation and prolonged lower-intensity maintenance are two strategies that have been used to deepen responses and delay progression. For older patients not eligible for ASCT, lenalidomide (len) is increasingly being used as part of frontline therapy, and current approaches are now targeting combinations of anti-CD38 antibodies. Strategies for selecting therapeutic regimens for older adults newly diagnosed with MM can be augmented with use of predictive tools to better capture physiologic age and estimate treatment tolerance. Here we review a decade of trials identifying clinical endpoints and toxicities relevant for the frontline treatment of younger patients and older adults.

Developments in continuous therapy and maintenance treatment approaches for patients with newly diagnosed multiple myeloma

The evolving paradigm of continuous therapy and maintenance treatment approaches in multiple myeloma (MM) offers prolonged disease control and improved outcomes compared to traditional fixed-duration approaches. Potential benefits of long-term strategies include sustained control of disease symptoms, as well as continued cytoreduction and clonal control, leading to unmeasurable residual disease and the possibility of transforming MM into a chronic or functionally curable condition. "Continuous therapy" commonly refers to administering a doublet or triplet regimen until disease progression, whereas maintenance approaches typically involve single-agent or doublet treatment following more intensive prior therapy with autologous stem cell transplant (ASCT) or doublet, triplet, or even quadruplet induction therapy. However, the requirements for agents and regimens within these contexts are similar: treatments must be tolerable for a prolonged period of time, should not be associated with cumulative or chronic toxicity, should not adversely affect patients' quality of life, should ideally be convenient with a minimal treatment burden for patients, and should not impact the feasibility or efficacy of subsequent treatment at relapse. Multiple agents have been and are being investigated as long-term options in the treatment of newly diagnosed MM (NDMM), including the immunomodulatory drugs lenalidomide and thalidomide, the proteasome inhibitors bortezomib, carfilzomib, and ixazomib, and the monoclonal antibodies daratumumab, elotuzumab, and isatuximab. Here we review the latest results with long-term therapy approaches in three different settings in NDMM: (1) maintenance treatment post ASCT; (2) continuous frontline therapy in nontransplant patients; (3) maintenance treatment post-frontline therapy in the nontransplant setting. We also discuss evidence from key phase 3 trials. Our review demonstrates how the paradigm of long-term treatment is increasingly well-established across NDMM treatment settings, potentially resulting in further improvements in patient outcomes, and highlights key clinical issues that will need to be addressed in order to provide optimal benefit.

Achieving minimal residual disease-negative by multiparameter flow cytometry may ameliorate a poor prognosis in MM patients with high-risk cytogenetics: a retrospective single-center analysis

The aim of our study was to evaluate the prognostic impact of minimal residual disease (MRD) and high-risk cytogenetics (HRCs) on outcomes in multiple myeloma (MM) patients. We applied multiparameter flow cytometry (MFC) to detect MRD in 123 consecutive patients diagnosed with MM for the first time who achieved very good partial remission (VGPR) or better after bortezomib or thalidomide-based induction therapy. Moreover, we examined the cytogenetic features of MM patients using magnetic-activated cell sorting and interphase fluorescence in situ hybridization (MACS-iFISH) at diagnosis. In all 123 MM patients, progression-free survival (PFS) and overall survival (OS) were better in the MRD- group (n = 31) than in the MRD+ group (n = 92) (median PFS: not reached (NR) vs. 26 months (m), P = 0.0002; 4-year OS, 91.7% vs. 66.3%, P = 0.008). PFS and OS were significantly shorter for each increase of one log per MRD level (P < 0.0001 and P = 0.001). The median PFS of the four groups according to the ratio of aberrant plasma cells (less than 0.01%, 0.01-0.1%, 0.1-1%, and more than 1%) were NR, 37 m, 26 m, and 15 m, respectively, and the 4-year OS rates were 91.7%, 69.3%, 76.1%, and 54.0%, respectively. In addition, our results show that PFS and OS were better for the standard-risk cytogenetic (SRC) patients than the HRC patients (median PFS: NR vs. 26 m, P = 0.004; 3-year OS: 95.8% vs. 76.0%, P = 0.006). The independent predictors of PFS were HRC and MRD+, which had hazard ratios of 1.901 (95% CI 1.094-3.303) and 3.486 (95% CI 1.449-8.386), respectively; while those for OS were an LDH level ≥ 250 U/L, HRC, and MRD+, which had hazard ratios of 2.789 (95% CI 1.080-7.199), 2.697 (95% CI 1.053-6.907), and 7.714 (95% CI 1.040-57.227), respectively. Furthermore, for SRC patients or HRC patients, PFS and OS were all longer in MRD- than in MRD+ patients. Strikingly, there was no significant difference in PFS or OS between the MRD-HRC and MRD+SRC groups (median PFS 45 vs. 34 m, P = 0.300; 4-year OS 100% vs. 83.6%, P = 0.196). PFS was superior in MRD-SRC than in MRD-HRC (NR vs. 45 m, P = 0.035); however, there was no significant difference in the 4-year OS between MRD-SRC and MRD-HRC (87.5% vs 100%, P = 0.480). MRD+ and HRCs were both independent prognostic factors in MM patients. Moreover, achieving MRD- may ameliorate a poor prognosis in MM patients with HRCs.

Immunotherapy in myeloma: how far have we come?

The treatment of multiple myeloma (MM) has evolved substantially over the past decades, leading to a significantly improved outcome of MM patients. The introduction of high-dose therapy, especially, and autologous stem cell transplantation, as well as the development of new drugs, such as immunomodulatory drugs (IMiDs) and proteasome inhibitors have contributed to the improvement in survival. However, eventually most MM patients relapse, which indicates that there is a need for new agents and novel treatment strategies. Importantly, the long-term survival in a subset of MM patients after allogeneic stem cell transplantation illustrates the potential of immunotherapy in MM, but allogeneic stem cell transplantation is also associated with a high rate of treatment-related mortality. Recently, a better insight into several immune-evasion mechanisms, which contribute to tumor progression, has resulted in the development of active and well-tolerated novel forms of immunotherapy. These immunotherapeutic agents can be used as monotherapy, or, even more successfully, in combination with other established anti-MM agents to further improve depth and duration of response by preventing the outgrowth of resistant clones. This review will discuss the mechanisms used by MM cells to evade the immune system, and also provide an overview of currently approved immunotherapeutic drugs, such as IMiDs (e.g. lenalidomide and pomalidomide) and monoclonal antibodies that target cell surface antigens present on the MM cell (e.g. elotuzumab and daratumumab), as well as novel immunotherapies (e.g. chimeric antigen receptor T-cells, bispecific antibodies and checkpoint inhibitors) currently in clinical development in MM.