The role of maintenance thalidomide therapy in multiple myeloma: MRC Myeloma IX results and meta-analysis

Bortezomib, thalidomide, and dexamethasone with or without daratumumab and followed by daratumumab maintenance or observation in transplant-eligible newly diagnosed multiple myeloma: long-term follow-up of the CASSIOPEIA randomised controlled phase 3 trial

BACKGROUND

CASSIOPEIA part 1 demonstrated superior depth of response and prolonged progression-free survival with daratumumab in combination with bortezomib, thalidomide, and dexamethasone (D-VTd) versus bortezomib, thalidomide, and dexamethasone (VTd) alone as an induction and consolidation regimen in transplant-eligible patients newly diagnosed with myeloma. In CASSIOPEIA part 2, daratumumab maintenance significantly improved progression-free survival and increased minimal residual disease (MRD)-negativity rates versus observation. Here, we report long-term study outcomes of CASSIOPEIA.

METHODS

CASSIOPEIA was a two-part, open-label, phase 3 trial of patients done at 111 European academic and community-based centres. Eligible patients were aged 18-65 years with transplant-eligible newly diagnosed myeloma and an Eastern Cooperative Oncology Group performance status of 0-2. In part 1, patients were randomly assigned (1:1) to pre-transplant induction and post-transplant consolidation with D-VTd or VTd. Patients who completed consolidation and had a partial response or better were re-randomised (1:1) to intravenous daratumumab maintenance (16 mg/kg every 8 weeks) or observation for 2 years or less. An interactive web-based system was used for both randomisations, and randomisation was balanced using permuted blocks of four. Stratification factors for the first randomisation (induction and consolidation phase) were site affiliation, International Staging System disease stage, and cytogenetic risk status. Stratification factors for the second randomisation (maintenance phase) were induction treatment and depth of response in the induction and consolidation phase. The primary endpoint for the induction and consolidation phase was the proportion of patients who achieved a stringent complete response after consolidation; results for this endpoint remain unchanged from those reported previously. The primary endpoint for the maintenance phase was progression-free survival from second randomisation. Efficacy evaluations in the induction and consolidation phase were done on the intention-to-treat population, which included all patients who underwent first randomisation, and efficacy analyses in the maintenance phase were done in the maintenance-specific intention-to-treat population, which included all patients who were randomly assigned at the second randomisation. This analysis represents the final data cutoff at the end of the study. The trial is registered with ClinicalTrials.gov, NCT02541383.

FINDINGS

Between Sept 22, 2015 and Aug 1, 2017, 1085 patients were randomly assigned to D-VTd (n=543) or VTd (n=542); between May 30, 2016 and June 18, 2018, 886 were re-randomised to daratumumab maintenance (n=442) or observation (n=444). At the clinical cutoff date, Sept 1, 2023, median follow-up was 80·1 months (IQR 75·7-85·6) from first randomisation and 70·6 months (66·4-76·1) from second randomisation. Progression-free survival from second randomisation was significantly longer in the daratumumab maintenance group than the observation-alone group (median not reached [95% CI 79·9-not estimable (NE)] vs 45·8 months [41·8-49·6]; HR 0·49 [95% CI 0·40-0·59]; p<0·0001); benefit was observed with D-VTd with daratumumab maintenance versus D-VTd with observation (median not reached [74·6-NE] vs 72·1 months [52·8-NE]; 0·76 [0·58-1·00]; p=0·048) and VTd with daratumumab maintenance versus VTd with observation (median not reached [66·9-NE] vs 32·7 months [27·2-38·7]; 0·34 [0·26-0·44]; p<0·0001).

INTERPRETATION

The long-term follow-up results of CASSIOPEIA show that including daratumumab in both the induction and consolidation phase and the maintenance phase led to superior progression-free survival outcomes. Our results confirm D-VTd induction and consolidation as a standard of care, and support the option of subsequent daratumumab monotherapy maintenance, for transplant-eligible patients with newly diagnosed multiple myeloma.

FUNDING

Intergroupe Francophone du Myélome, Dutch-Belgian Cooperative Trial Group for Hematology Oncology, and Janssen Research & Development.

Role of Consolidation and Maintenance

Consolidation therapy consists of short-term therapy after stem cell transplant in multiple myeloma. Key consolidation trials have shown mixed results on whether consolidation should be included after transplant, leading to varied clinical practice. Maintenance therapy consists of long-term, typically fixed-duration or indefinite, therapy. Standard-risk patients typically receive single-agent therapy, whereas high-risk may benefit from doublet therapy and beyond. Adverse events and quality of life concerns should be considered, as optimal duration of maintenance therapy continues to be studied.

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.

Lenalidomide and dexamethasone maintenance with or without ixazomib, tailored by residual disease status in myeloma

From November 2014 to May 2017, 332 patients homogeneously treated with bortezomib, lenalidomide, and dexamethasone (VRD) induction, autologous stem cell transplant, and VRD consolidation were randomly assigned to receive maintenance therapy with lenalidomide and dexamethasone (RD; 161 patients) vs RD plus ixazomib (IRD; 171 patients). RD consisted of lenalidomide 15 mg/d from days 1 to 21 plus dexamethasone 20 mg/d on days 1 to 4 and 9 to 12 at 4-week intervals, whereas in the IRD arm, oral ixazomib at a dose of 4 mg on days 1, 8, and 15 was added. Therapy for patients with negative measurable residual disease (MRD) after 24 cycles was discontinued, whereas those who tested positive for MRD remained on maintenance with RD for 36 more cycles. After a median follow-up of 69 months from the initiation of maintenance, the progression-free survival (PFS) was similar in both arms, with a 6-year PFS rate of 61.3% and 55.6% for RD and IRD, respectively (hazard ratio, 1.136; 95% confidence interval, 0.809-1.603). After 2 years of maintenance, treatment was discontinued in 163 patients with negative MRD, whereas 63 patients with positive MRD continued with RD therapy. Maintenance discontinuation in patients tested negative for MRD resulted in a low progression rate (17.2% at 4 years), even in patients with high-risk features. In summary, our results show the efficacy of RD maintenance and support the safety of maintenance therapy discontinuation in patients with negative MRD at 2 years. This trial was registered at www.clinicaltrials.gov as #NCT02406144 and at EudraCT as 2014-00055410.

Cellular immunity in the era of modern multiple myeloma therapy

Multiple myeloma (MM) is a relapsing clonal plasma cell malignancy and incurable thus far. With the increasing understanding of myeloma, highlighting the critical importance of the immune system in the pathogenesis of MM is essential. The immune changes in MM patients after treatment are associated with prognosis. In this review, we summarize currently available MM therapies and discuss how they affect cellular immunity. We find that the modern anti-MM treatments enhance antitumour immune responses. A deeper understanding of the therapeutic activity of individual drugs offers more effective treatment approaches that enhance the beneficial immunomodulatory effects. Furthermore, we show that the immune changes after treatment in MM patients can provide useful prognostic marker. Analysing cellular immune responses offers new perspectives for evaluating clinical data and making comprehensive predictions for applying novel therapies in MM patients.

Maintenance lenalidomide in newly diagnosed transplant eligible and non-eligible myeloma patients; profiling second primary malignancies in 4358 patients treated in the Myeloma XI Trial

Background

Early trials of long-term lenalidomide use reported an increased incidence of second primary malignancy (SPM), including acute myeloid leukaemia and myelodysplastic syndrome. Later, meta-analysis suggested the link to be secondary to lenalidomide in combination with melphalan.

Methods

Myeloma XI is a large, phase III randomised trial in-which lenalidomide was used at induction and maintenance, in transplant eligible (TE) and non-eligible (TNE) newly diagnosed patients (NCT01554852). Here we present an analysis of SPM incidence and profile the SPM type to determine the impact of autologous stem cell transplantation (ASCT) and lenalidomide exposure in 4358 patients treated on study. Data collection took place from the start of the trial in May 2010, to May 2019, as per the protocol timeline. The Median follow-up following maintenance randomisation was 54.5 and 46.1 months for TE and TNE patients, respectively.

Findings

In the TE pathway, the overall SPM incidence was 7.7% in lenalidomide maintenance patients compared to 3.2% in those being observed (p = 0.006). Although the TNE lenalidomide maintenance patients had the greatest SPM incidence (15.4%), this was not statistically significant when compared to the observed patients (10%, p = 0.10).The SPM incidence was higher in patients who received lenalidomide at induction and maintenance (double exposure), when compared to those treated with lenalidomide at one time point (single exposure). Again, this was most marked in TNE patients where the overall SPM incidence was 16.9% in double exposed patients, compared to 11.7% in single exposed patients, and 11.2% in patients who did not receive lenalidomide (p = 0.04). This is likely an effect of treatment duration, with the median number of cycles being 27 in the TNE double exposed patients, vs 6 in the single exposure patients.Haematological SPMs were uncommon, diagnosed in 50 patients (incidence 1.1%). The majority of cases were diagnosed in TE patients treated with lenalidomide maintenance (n = 25, incidence 2.8%), suggesting a possible link with melphalan. Non-melanoma skin cancer incidence was highest in patients receiving lenalidomide maintenance, particularly in TNE patients, where squamous cell carcinoma and basal cell carcinoma were diagnosed in 5.5% and 2.6% of patients, respectively. The incidence of most solid tumour types was higher in lenalidomide maintenance patients.Mortality due to progressive myeloma was reduced in patients receiving lenalidomide maintenance, noted to be 16.6% compared 22.6% in those observed in TE patients and 32.7% compared to 41.5% in TNE patients. SPM related mortality was low, 1.8% and 6.1% in TE and TNE lenalidomide maintenance patients, respectively, compared to 0.4% and 2.8% in those being observed.

Interpretation

This provides reassurance that long-term lenalidomide treatment is safe and associated with improved outcomes in TE and TNE populations, although monitoring for SPM development should be incorporated into clinic review processes.

Funding

Primary financial support was from Cancer Research UK [C1298/A10410].

Lenalidomide or bortezomib as maintenance treatment remedy the inferior impact of high-risk cytogenetic abnormalities in non-transplant patients with newly diagnosed multiple myeloma: a real-world multi-centered study in China

Maintenance treatment is a pivotal part in the whole process management of multiple myeloma (MM), which further deepens response and improves survival. However, evidence of maintenance in non-transplant MM patients is inadequate in real-world practice. Here, we retrospectively analyzed the efficacy and survival of 375 non-transplant MM patients from 11 centers between 2010 and 2021 in north China. After a median of seven cycles of front-line regimens, there were 141, 79, and 155 patients receiving lenalidomide maintenance (L-MT), bortezomib maintenance (B-MT), or thalidomide maintenance (T-MT), respectively. Patients on L-MT and B-MT had significantly greater proportions of high-risk cytogenetic abnormalities (HRCAs) detected by fluorescence in situ hybridization (FISH), which was defined as 1q21 gain, 17p deletion, adverse immunoglobulin heavy chain (IgH) translocations. Although the progression-free survival (PFS) and overall survival (OS) were comparable among the three groups, L-MT and B-MT remedied the negative impact of HRCAs on survival (PFS of patients with HRCAs vs. patients without HRCAs: L-MT, 26.9 vs. 39.2 months, p=0.19; B-MT, 20.0 vs. 29.7 months, p=0.36; OS not reached in all groups). Patients with HRCAs in the T-MT group presented inferior clinical outcomes compared to standard-risk patients (PFS, 12.1 vs. 22.8 months, p=0.02, HR=1.8, 95% CI 1.0-3.4; OS, 54.9 months vs. NR, p<0.001, HR=3.2, 95% CI 1.5-7.0). Achieving complete response (CR) after induction therapy led to superior PFS compared to other degrees of response, regardless of maintenance medication. Furthermore, maintenance duration over 24 months correlated with favorable survival. Due to the large gap of transplant eligibility in China, optimizing maintenance therapy is important for non-transplant MM patients. In this real-world multi-centered study, our findings suggest that clinicians prefer to prescribe lenalidomide or bortezomib as maintenance therapy in high-risk settings, which are superior to thalidomide in non-transplant MM patients. Achievement of CR and maintenance duration over 2 years are positive factors that influence survival.

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.

Early versus Late Discontinuation of Maintenance Therapy in Multiple Myeloma

Maintenance therapy after autologous stem cell transplant (ASCT) in multiple myeloma (MM) is the standard treatment and recommended to be continued until disease progression. However, in the real world, patients discontinue treatment due to various reasons. We sought to determine the effect of early versus late discontinuation on survival outcomes in MM patients who underwent ASCT at The Ohio State University. We retrospectively reviewed 340 patients who underwent ASCT from 2005 to 2016 and received maintenance therapy for at least six months without progression. We compared the outcomes of patients who received maintenance for three years or less (early group) to the patients who continued maintenance beyond three years (late group). Lenalidomide (89%) and bortezomib (10%) were the most common agents used for maintenance chemotherapy. In Kaplan−Meier analysis, patients in the late group had prolonged progression-free (PFS) (p < 0.001) and overall survival (OS) (p < 0.001). The 5-year estimated OS in late group was 96% vs. 79% in the early group and 5-year PFS was 80% in late group vs. 50% in the early group. The most common reasons for discontinuation of maintenance in early group were adverse events (55.9%) and patient preference (22.5%). For the late group, it was disease progression (23.9%) and adverse events (14.3%). Fifty-five percent of patients in the late group were still on maintenance treatment at the last follow-up. Continuation of maintenance therapy was thus associated with improved outcomes, while adverse events prevented most patients from continuing treatment.

What's Old is New: The Past, Present and Future Role of Thalidomide in the Modern-Day Management of Multiple Myeloma

Immunomodulatory drugs (IMiDs) have become an integral part of therapy for both newly diagnosed and relapsed/refractory multiple myeloma (RRMM). IMiDs bind to cereblon, leading to the degradation of proteins involved in B-cell survival and proliferation. Thalidomide, a first-generation IMiD, has little to no myelosuppressive potential, negligible renal clearance, and long-proven anti-myeloma activity. However, thalidomide's adverse effects (e.g., somnolence, constipation, and peripheral neuropathy) and the advent of more potent therapeutic options has led to the drug being less frequently used in many countries, including the US and Canada. Newer-generation IMiDs, such as lenalidomide and pomalidomide, are utilized far more frequently. In numerous previous trials, salvage therapy with thalidomide (50-200 mg/day) plus corticosteroids (with or without selected cytotoxic or targeted agents) has been shown to be effective and well-tolerated in the RRMM setting. Hence, thalidomide-based regimens remain important alternatives for heavily pretreated patients, especially for those who have no access to novel therapies and/or are not eligible for their use (due to renal failure, high-grade myelosuppression, or significant comorbidities). Ongoing and future trials may provide further insights into the current role of thalidomide, especially by comparing thalidomide-containing regimens with protocols based on newer-generation IMiDs and by investigating thalidomide's association with novel therapies (e.g., antibody-drug conjugates, bispecific antibodies, and chimeric antigen receptor T cells).

A review of the current status of lenalidomide maintenance therapy in multiple myeloma in 2022

INTRODUCTION

Recent advances in the diagnosis and management of multiple myeloma (MM) have improved patient outcomes. This progress in our understanding of MM has resulted in continuous suppressive therapy concepts, including induction, high dose chemotherapy with autologous stem cell transplantation (ASCT), consolidation, and maintenance therapy. The foundation of maintenance therapy has been with lenalidomide. Other novel immunomodulatory drugs (IMiDs), proteasome inhibitors (PIs), and targeted monoclonal antibodies have also contributed to this evolution.

AREAS COVERED

This review summarizes the outcomes from phase II/III trials with long-term lenalidomide maintenance therapy alone or in combination with other agents in post-ASCT and non-transplant settings for newly diagnosed patients with MM. We review recent data considering a combination with newer medications and ongoing trials. We also review the optimal duration, MRD negativity rate, and safety and tolerability aspects of lenalidomide maintenance therapy. This review aims to present the current and emerging clinical evidence that supports using lenalidomide as a backbone for maintenance therapy in patients with MM.

EXPERT OPINION

There is increasing evidence to support lenalidomide as the backbone of combination therapy in the maintenance setting.

Anti-CD19 and anti-BCMA CAR T cell therapy followed by lenalidomide maintenance after autologous stem-cell transplantation for high-risk newly diagnosed multiple myeloma

Few prospective studies have examined posttransplant chimeric antigen receptor (CAR) T cell infusion as candidates for front-line consolidation therapy for high-risk multiple myeloma (MM) patients. This single-arm exploratory clinical trial is the first to evaluate the safety and efficacy of sequential anti-CD19 and anti-BCMA CAR-T cell infusion, followed by lenalidomide maintenance after autologous stem cell transplantation (ASCT), in 10 high-risk newly diagnosed multiple myeloma (NDMM) patients. The treatment was generally well tolerated, with hematologic toxicities being the most common grade 3 or higher adverse events. All patients had cytokine release syndrome (CRS), which was grade 1 in 5 patients (50%) and grade 2 in 5 patients (50%). No neurotoxicity was observed after CAR-T cell infusion. The overall response rate was 100%, with the best response being 90% for a stringent complete response (sCR), and 10% for a complete response (CR). At a median follow-up of 42 (36-49) months, seven (70%) of 10 patients showed sustained minimal residual disease (MRD) negativity for more than 2 years. The median progression-free survival (PFS) and overall survival (OS) were not reached. Although the sample size was small and there was a lack of control in this single-arm study, the clinical benefits observed warrant ongoing randomized controlled trials.

Impact of autologous transplantation on survival in patients with newly diagnosed multiple myeloma who have high-risk cytogenetics: A meta-analysis of randomized controlled trials

BACKGROUND

Despite routine evaluation of cytogenetics in myeloma, little is known regarding the impact of high-dose therapy (HDT) consolidation on overall survival (OS) or progression-free survival (PFS) in patients who have high-risk cytogenetics. The authors performed a meta-analysis of randomized controlled trials (RCTs) to assess the heterogeneity of HDT efficacy according to cytogenetic risk.

METHODS

All RCTs in patients who had newly diagnosed myeloma from 2000 to 2021 that compared upfront HDT versus standard-dose therapy (SDT) consolidation were included. The primary objective was to assess the difference in HDT efficacy between standard-risk and high-risk cytogenetics in terms of the OS or PFS log(hazard ratio) (HR). The pooled OS and PFS HR was calculated according to cytogenetic-risk subgroup using a random-effects model, and heterogeneity (I² ) (the percentage of total observed variability explained by between-study differences) was assessed using an interaction test.

RESULTS

After screening 3307 citations, 6 RCTs were included for PFS analysis, and 4 were included for OS analysis. The median follow-up ranged from 3.1 to 7.8 years. The pooled OS HR for HDT versus SDT consolidation in patients with standard-risk and high-risk cytogenetics was 0.90 (95% confidence interval [CI], 0.70-1.17; I² = 0%) and 0.66 (95% CI, 0.45-0.97; I² = 0%), respectively. The difference in HDT efficacy in terms of OS between standard-risk and high-risk patients was statistically significant in favor of the high-risk group (P for interaction = .03). The pooled PFS HR for HDT versus SDT was 0.65 (95% CI 0.56-0.76; I² = 0%) versus 0.52 (95% CI, 0.33-0.83; I² = 55%), respectively. The difference in HDT efficacy in terms of PFS between standard-risk and high-risk patients was not significant (P for interaction = .25).

CONCLUSIONS

The magnitude of OS benefit with upfront HDT is cytogenetics-dependent. Patients with high-risk cytogenetics should preferably receive upfront rather than delayed HDT consolidation.

LAY SUMMARY

Upfront autologous stem cell transplantation improves overall survival in patients with newly diagnosed myeloma harboring high-risk cytogenetics.

Impact of Etiological Cytogenetic Abnormalities on the Depth of Immunoparesis and Survival in Newly Diagnosed Multiple Myeloma

INTRODUCTION/BACKGROUND

Immunoparesis, or low polyclonal immunoglobulin levels, is commonly seen in multiple myeloma (MM), and is associated with poor clinical outcomes. MM can be divided into subgroups with distinct biology and outcomes based on etiologic cytogenetic abnormalities. These include hyperdiploidy and translocations of t(11;14), t(4;14), t(14;16), and t(14;20), with the latter 3 associated with high-risk disease. We hypothesized that the different etiologic cytogenetic abnormalities drive bone marrow microenvironmental changes, resulting in different degrees of immunoparesis, and subgroup-dependent effects on clinical outcomes.

MATERIALS AND METHODS

We performed a retrospective review of 985 newly diagnosed patients enrolled in the Myeloma IX and XI trials. Immunoglobulin levels, survival outcomes, and infection rates were evaluated for each cytogenetic subgroup.

RESULTS

A significant proportion of patients with high-risk t(4;14), t(14;16), or t(14;20) had suppressed polyclonal immunoglobulins compared to standard-risk patients with hyperdiploidy or t(11;14). The clinical impact of immunoparesis depended on the cytogenetic subgroup, with the degree of IgM suppression effecting progression-free and overall survival only in the hyperdiploid subgroup. There was no significant difference in infection rates amongst the etiologic subgroups.

CONCLUSION

These findings demonstrate that the etiologic cytogenetic subgroup influences the degree and clinical impact of immunoparesis. This suggests that the underlying cytogenetic abnormality affects remodeling of the bone marrow plasma cell niche, resulting in suppressed normal plasma cell function, and low immunoglobulin levels.

Significance of maintenance therapy after HDT/ASCT in symptomatic multiple myeloma: A multicenter retrospective analysis in Kansai Myeloma Forum

A total of 129 symptomatic patients with multiple myeloma (MM) who underwent high-dose chemotherapy with autologous stem cell transplantation (HDT/ASCT) were analyzed. The 4-year overall survival (OS) of patients with maintenance (n = 82) was 80%, whereas that of patients without maintenance (n = 47) was 72% (p = 0.426). The 4-year progression-free survival (PFS) of patients with maintenance was 38%, whereas that of patients without maintenance was 27% (p = 0.088). Multivariate analysis revealed that an International Staging System score ≥2 was associated with worse PFS (hazard ratio 1.62, p = 0.043). Among the 129 patients, two were excluded owing to early relapse, 50 patients achieved complete response (CR), and 77 patients failed to achieve CR. Patients who achieved CR showed better 4-year PFS than those who failed to achieve CR (41% vs. 30%, p = 0.027); however, 4-year OS was not different (76% vs. 82%, p = 0.971). In patients who achieved CR, 4-year OS with/without maintenance was 74%/81% (p = 0.357), 4-year PFS with/without maintenance was 42%/40% (p = 0.954). In patients who failed to achieve CR, the 4-year OS with/without maintenance was 97%/91% (p = 0.107), and 4-year PFS with/without maintenance was 36%/16% (p < 0.001). In patients who failed to achieve CR, maintenance significantly improved the PFS. Maintenance after HDT/ASCT can prolong PFS in patients who fail to achieve CR in real-world settings.

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.

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.

Lenalidomide before and after autologous stem cell transplantation for transplant-eligible patients of all ages in the randomized, phase III, Myeloma XI trial

The optimal way to use immunomodulatory drugs as components of induction and maintenance therapy for multiple myeloma is unresolved. We addressed this question in a large phase III randomized trial, Myeloma XI. Patients with newly diagnosed multiple myeloma (n = 2042) were randomized to induction therapy with cyclophosphamide, thalidomide, and dexamethasone (CTD) or cyclophosphamide, lenalidomide, and dexamethasone (CRD). Additional intensification therapy with cyclophosphamide, bortezomib and dexamethasone (CVD) was administered before ASCT to patients with a suboptimal response to induction therapy using a response-adapted approach. After receiving high-dose melphalan with autologous stem cell transplantation (ASCT), eligible patients were further randomized to receive either lenalidomide alone or observation alone. Co-primary endpoints were progression-free survival (PFS) and overall survival (OS). The CRD regimen was associated with significantly longer PFS (median: 36 vs. 33 months; hazard ratio [HR], 0.85; 95% confidence interval [CI], 0.75-0.96; P = 0.0116) and OS (3-year OS: 82.9% vs. 77.0%; HR, 0.77; 95% CI, 0.63-0.93; P = 0.0072) compared with CTD. The PFS and OS results favored CRD over CTD across all subgroups, including patients with International Staging System stage III disease (HR for PFS, 0.73; 95% CI, 0.58-0.93; HR for OS, 0.78; 95% CI, 0.56-1.09), high-risk cytogenetics (HR for PFS, 0.60; 95% CI, 0.43-0.84; HR for OS, 0.70; 95% CI, 0.42-1.15) and ultra high-risk cytogenetics (HR for PFS, 0.67; 95% CI, 0.41-1.11; HR for OS, 0.65; 95% CI, 0.34-1.25). Among patients randomized to lenalidomide maintenance (n = 451) or observation (n = 377), maintenance therapy improved PFS (median: 50 vs. 28 months; HR, 0.47; 95% CI, 0.37-0.60; P < 0.0001). Optimal results for PFS and OS were achieved in the patients who received CRD induction and lenalidomide maintenance. The trial was registered with the EU Clinical Trials Register (EudraCT 2009-010956-93) and ISRCTN49407852.

Current approaches to management of high-risk multiple myeloma

The median overall survival in multiple myeloma is rapidly approaching 10 years; however, in nearly a fifth of patients the prognosis remains poor. Therefore, the modern-day management of myeloma patients should be individualized, with a more intense and continuous approach in these high-risk patients. This includes first-line treatment based on multi-drug combinations employing the most effective drug combinations, upfront autologous stem cell transplantation (in eligible patients with tandem transplantation being a consideration), and maintenance based on proteasome inhibitor-based combinations. This paper reviews the results of recent retrospective analyses and clinical trials, but also gives a glance into the future by presenting the ongoing trials.

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.

Autologous Stem-Cell Transplantation for Multiple Myeloma in the Era of Novel Therapies

Despite the evolution of the therapeutic arsenal for the treatment of multiple myeloma (MM) over the past decade, autologous stem-cell transplantation (ASCT) remains an integral part of the treatment of patients with both newly diagnosed and relapsed MM. The advent of novel therapies, such as immunomodulatory agents, proteasome inhibitors, and monoclonal antibodies, has led to unprecedented levels of deep hematologic responses. Nonetheless, studies show that ASCT has an additive effect leading to additional deepening of responses. As the therapeutic agents for MM continue to evolve, the timing, duration, and sequence of their use in combination with ASCT will be crucial to understand to obtain the deepest response and survival benefit for patients with MM. This review aims to discuss the role of ASCT for the management of MM, with a particular focus on the role of ASCT in the context of novel therapies and minimal residual disease.

Propensity-score matched analysis of the efficacy of maintenance/continuous therapy in newly diagnosed patients with multiple myeloma: a multicenter retrospective collaborative study of the Japanese Society of Myeloma

BACKGROUND

Maintenance ± consolidation or continuous therapy is considered a standard of care for both transplant-eligible and -ineligible patients with multiple myeloma (MM). However, long-term benefits of such therapy have not yet been clarified in the context of clinical practice.

PURPOSE

To clarify the efficacy of maintenance/continuous approach, we retrospectively analyzed the cohort data of newly diagnosed MM patients by propensity-score matching based on age, gender, revised International Staging System (R-ISS) stage, and implementation of transplantation to reduce the bias due to confounding variables.

FINDINGS

Among 720 patients, 161 were identified for each of the maintenance and no maintenance groups. Maintenance/continuous therapy employed immunomodulatory drugs (n = 83), proteasome inhibitors (n = 48), combination of both (n = 29), or dexamethasone alone (n = 1). Progression-free survival (PFS) was significantly prolonged in the maintenance group compared with the no maintenance group (median 37.7 and 21.9 months, p = 0.0002, respectively). Prolongation of PFS was observed in both transplanted and non-transplanted patients (p = 0.017 and p = 0.0008, respectively), with standard risk (p < 0.00001), R-ISS stage I (p = 0.037) and stage II (p = 0.00094), and those without obtaining complete response (p = 0.0018). There was no significant benefit in overall survival (OS), but it tended to be better in the maintenance group in non-transplanted patients. Regarding the treatment pattern, the substitution or addition of drugs different from the induction therapy and the combination with immunomodulatory drugs and proteasome inhibitors appeared to be more beneficial for PFS but not OS.

CONCLUSION

These results support the benefit of current maintenance/continuous approach in routine clinical practice in the management of MM.

Future Directions in Maintenance Therapy in Multiple Myeloma

Autologous stem cell transplantation (ASCT) has been a backbone of therapy for newly diagnosed patients with multiple myeloma eligible for high-dose therapy for decades. Survival outcomes have continued to improve over time, in part because of the incorporation of highly effective induction regimens prior to ASCT as well as post-ASCT maintenance therapy. Randomized phase III clinical trials have helped establish lenalidomide maintenance as a standard of care. However, as nearly all patients will eventually experience disease relapse, there continues to be significant interest in developing novel maintenance strategies to improve upon lenalidomide maintenance. In this review, we summarize the available evidence for the use of immunomodulatory drugs, proteasome inhibitors, and monoclonal antibodies as post-ASCT maintenance therapies as well as discuss future directions and unanswered questions in the field.

Prognostic and predictive performance of R-ISS with SKY92 in older patients with multiple myeloma: the HOVON-87/NMSG-18 trial

The standard prognostic marker for multiple myeloma (MM) patients is the revised International Staging System (R-ISS). However, there is room for improvement in guiding treatment. This applies particularly to older patients, in whom the benefit/risk ratio is reduced because of comorbidities and subsequent side effects. We hypothesized that adding gene-expression data to R-ISS would generate a stronger marker. This was tested by combining R-ISS with the SKY92 classifier (SKY-RISS). The HOVON-87/NMSG-18 trial (EudraCT: 2007-004007-34) compared melphalan-prednisone-thalidomide followed by thalidomide maintenance (MPT-T) with melphalan-prednisone-lenalidomide followed by lenalidomide maintenance (MPR-R). From this trial, 168 patients with available R-ISS status and gene-expression profiles were analyzed. R-ISS stages I, II, and III were assigned to 8%, 75%, and 7% of patients, respectively (3-year overall survival [OS] rates: 80%, 65%, 33%, P = 8 × 10-3). Using the SKY92 classifier, 13% of patients were high risk (HR) (3-year OS rates: standard risk [SR], 70%; HR, 28%; P < .001). Combining SKY92 with R-ISS resulted in 3 risk groups: SKY-RISS I (SKY-SR + R-ISS-I; 15%), SKY-RISS III (SKY-HR + R-ISS-II/III; 11%), and SKY-RISS II (all other patients; 74%). The 3-year OS rates for SKY-RISS I, II, and III are 88%, 66%, and 26%, respectively (P = 6 × 10-7). The SKY-RISS model was validated in older patients from the CoMMpass dataset. Moreover, SKY-RISS demonstrated predictive potential: HR patients appeared to benefit from MPR-R over MPT-T (median OS, 55 and 14 months, respectively). Combined, SKY92 and R-ISS classify patients more accurately. Additionally, benefit was observed for MPR-R over MPT-T in SKY92-RISS HR patients only.

Evolution of Treatment Paradigms in Newly Diagnosed Multiple Myeloma

The plasma cell neoplasm multiple myeloma (MM) is currently considered incurable. However, significant advances in treatment options over the past 20 years have led to unprecedented response rates to initial therapy as well as prolonged survival rates. Induction regimens have evolved from alkylator-based therapies to those consisting of immunomodulatory drugs and proteasome inhibitors. The combination of bortezomib/lenalidomide/dexamethasone (VRd) has emerged as a standard regimen for both transplant-eligible (TE) and transplant-ineligible (TI) patient populations. More recent efforts have focused on the incorporation of monoclonal antibody therapy into the newly diagnosed setting, particularly anti-CD38 monoclonal antibodies. In the TI patient population, the combination of daratumumab/lenalidomide/dexamethasone is now considered another standard therapy. In the TE setting, it remains to be determined whether the addition of daratumumab to the VRd backbone results in improved long-term outcomes. Recent studies have confirmed the progression-free survival benefit of upfront autologous stem cell transplant and have established lenalidomide maintenance as a standard of care. Multiple studies are evaluating whether inclusion of monoclonal antibody therapy in the maintenance setting will improve outcomes. The optimal management of newly diagnosed patients with high-risk cytogenetics remains to be determined. We discuss the emerging therapies that will likely shape management of newly diagnosed MM in the future.

Immunomodulators in newly diagnosed multiple myeloma: current and future concepts

Introduction: Impressive therapeutic progress is being made in the management of multiple myeloma (MM). his progress is related to the introduction of several new classes of therapeutic agents including proteasome inhibitors, immunomodulatory drugs (IMiDs) and monoclonal antibodies (MoAbs).Areas covered: In this manuscript, the role of the IMiDs thalidomide and lenalidomide in the management of newly diagnosed MM is discussed. The mode of action of IMiDs and their role in the management of newly diagnosed MM patients is highlighted. In addition, clinical data on how MoAbs such as the anti-CD38 antibody daratumumab can further increase the efficacy of IMiD-based first-line anti-myeloma regimens are provided. A database search in PubMed was carried out.Expert Opinion: Immunomodulation has become an indispensable part of successful anti-myeloma regimens both at relapse and at diagnosis. The combination of lenalidomide plus dexamethasone with an anti-CD38 MoAb such as daratumumab and a proteasome inhibitor such as bortezomib is currently one of the most potent first-line treatment regimens for MM. A better understanding on how IMiDs synergize with existing and new anti-myeloma treatments can further improve the outcome for patients. Optimal first-line therapy will continue to benefit the long-term outcome of a growing population of young and elderly MM patients.

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.

Optimising the value of immunomodulatory drugs during induction and maintenance in transplant ineligible patients with newly diagnosed multiple myeloma: results from Myeloma XI, a multicentre, open-label, randomised, Phase III trial

Second-generation immunomodulatory agents, such as lenalidomide, have a more favourable side-effect profile than the first-generation thalidomide, but their optimum combination and duration for patients with newly diagnosed transplant-ineligible myeloma (ND-TNE-MM) has not been defined. The most appropriate delivery and dosing regimens of these therapies for patients at advanced age and frailty status is also unclear. The Myeloma XI study compared cyclophosphamide, thalidomide and dexamethasone (CTDa) to cyclophosphamide, lenalidomide and dexamethasone (CRDa) as induction therapy, followed by a maintenance randomisation between ongoing therapy with lenalidomide or observation for patients with ND-TNE-MM. CRDa deepened response but did not improve progression-free (PFS) or overall survival (OS) compared to CTDa. However, analysis by age group highlighted significant differences in tolerability in older, frailer patients that may have limited treatment delivery and impacted outcome. Deeper responses and PFS and OS benefits with CRDa over CTDs were seen in patients aged ≤70 years, with an increase in toxicity and discontinuation observed in older patients. Our results highlight the importance of considering age and frailty in the approach to therapy for patients with ND-TNE-MM, highlighting the need for prospective validation of frailty adapted therapy approaches, which may improve outcomes by tailoring treatment to the individual.

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.

Phase II Trial of Maintenance Treatment With IL2 and Zoledronate in Multiple Myeloma After Bone Marrow Transplantation: Biological and Clinical Results

Background

Maintenance treatment after autologous bone marrow transplantation in multiple myeloma improves the outcome of patients. We designed a phase II clinical trial to evaluate the treatment with IL2 and zoledronate after autologous bone marrow transplantation in myeloma patients.

Methods

Patients with a histologically proven diagnosis of multiple myeloma become eligible if achieved a very good partial remission in bone marrow samples after 3 months from autologous bone marrow transplantation. IL2 was administered from day 1 to 7. In the first cycle, the daily dose was 2 × 10⁶ IU, whereas, in subsequent ones the IL2 dose was progressively escalated, with +25% increases at each cycle, until evidence of toxicity or up to 8 × 10⁶ IU. Four mg of zoledronic acid were infused on day 2. Flow cytometry analysis of γδ-lymphocytes was performed at days 1 and 8 of treatment cycles.

Results

Forty-four patients have been enrolled between 2013 and 2016. The median time to progression was 22.5 months (95% CI 9.7–35.2). A complete remission with a negative immunofixation was obtained in 18% of patients and correlated with a significantly longer time to progression (p = 0.015). Treatment was well tolerated without G3 or 4 toxicities. After a week of treatment with IL2 and zoledronate, γδ lymphocytes, Vγ9δ2, CD57+, effector, late effector, and memory γδ increased but in subsequent cycles, there was a progressive reduction of this expansion.

Conclusions

The maintenance treatment with IL2 and Zoledronate has a modest activity in myeloma patients after autologous bone marrow transplantation.

EudraCT Number

2013-001188-22.

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.

Efficacy of proteasome inhibitor-based maintenance following autologous transplantation in multiple myeloma: A systematic review and meta-analysis

INTRODUCTION

Lenalidomide maintenance, commonly prescribed in the postautologous transplantation (AHCT) setting for multiple myeloma (MM), is associated with development of secondary primary malignancies (SPM). Proteasome inhibitor maintenance (PIM) has also been evaluated in MM. We conduct a systematic review/meta-analysis to assess the efficacy of PIM in MM.

METHODS

Performing a comprehensive search of the medical literature using PubMed/Medline and EMBASE on September 11, 2019, we extracted data on clinical outcomes related to benefits (OS, PFS, and depth of hematologic response [DOHR]) and harms (SPM and adverse events). 2144 references were identified; three studies were eligible for inclusion.

RESULTS

A total of 1760 patients were included in the analysis; 507 patients received bortezomib and 395 received ixazomib maintenance. Control arms were either placebo (n = 261) or thalidomide (n = 358). PIM did not improve OS (HR 0.88, 95% CI 0.73-1.05, P = .15) but improved PFS (HR 0.77, 95% CI 0.69-0.86, P ≤ .00001) and DOHR (HR 0.88, 95% CI 0.79-0.98, P = .02) compared with control. There were no significant differences between PIM and control regarding SPM (p = NS) and ≥grade 3 peripheral neuropathy (PN) (p = NS).

CONCLUSIONS

PIM following AHCT in MM improves PFS and DOHR without an increase in development of SPM or severe PN compared with placebo/thalidomide.

Current and future perspectives of maintenance therapy in multiple myeloma

While the outcome of patients with multiple myeloma has significantly improved over the last two decades, the disease remains incurable for the majority of patients. With the advent of novel agents, there has been a shift towards prolonged therapy as opposed to fixed-duration therapy, aimed at improving progression-free survival and overall survival. Evidence favoring continuous therapy has emerged over the last 2 decades and in the context of maintenance after proteasome inhibitor plus immunomodulatory drug induction followed by high dose melphalan and stem cell transplantation, this leads to >80% overall survival at 5 years. Maintenance therapy specifically has been demonstrated to correlate with increasing depth of disease response with a significant proportion of patients who remain minimal residual disease positive at the end of induction therapy achieving minimal residual disease negativity with maintenance therapy both in clinical trials and selected real world populations. As the survival improves, it is crucial to identify patients who are projected to have better survival and spare them toxicities arising from indefinite maintenance therapy. The role of minimal residual disease in this context is being investigated in numerous clinical trials and in the next few years the goal should be to use this in a rational way to achieve the ability to identify patients who would require continuation or escalation of therapy to improve their projected survival as well as to identify the group of patients in whom maintenance therapy could perhaps be time-limited without compromising their survival. Here we review the evidence for maintenance therapy from the key trials in the past years, present an overview of the current landscape and our perspective of maintenance therapy in the future.

Thrombosis in patients with myeloma treated in the Myeloma IX and Myeloma XI phase 3 randomized controlled trials

Newly diagnosed multiple myeloma (NDMM) patients treated with immunomodulatory drugs are at high risk of venous thromboembolism (VTE), but data are lacking from large prospective cohorts. We present thrombosis outcome data from Myeloma IX (n = 1936) and Myeloma XI (n = 4358) phase 3 randomized controlled trials for NDMM that treated transplant-eligible and transplant-ineligible patients before and after publication of thrombosis prevention guidelines. In Myeloma IX, transplant-eligible patients randomly assigned to cyclophosphamide, vincristine, doxorubicin, and dexamethasone (CVAD) induction had higher risk of VTE compared with patients treated with cyclophosphamide, thalidomide, and dexamethasone (CTD) (22.5% [n = 121 of 538] vs 16.1% [n = 89 of 554]; adjusted hazard ratio [aHR],1.46; 95% confidence interval [95% CI], 1.11-1.93). For transplant-ineligible patients, those randomly assigned to attenuated CTD (CTDa) induction had a higher risk of VTE compared with those treated with melphalan and prednisolone (MP) (16.0% [n = 68 of 425] vs 4.1% [n = 17 of 419]; aHR, 4.25; 95% CI, 2.50-7.20). In Myeloma XI, there was no difference in risk of VTE (12.2% [n = 124 of 1014] vs 13.2% [n = 133 of 1008]; aHR, 0.92; 95% CI, 0.72-1.18) or arterial thrombosis (1.2% [n = 12 of 1014] vs 1.5% [n = 15 of 1008]; aHR, 0.80; 95% CI, 0.37-1.70) between transplant-eligible pathways for patients treated with cyclophosphamide, lenalidomide, and dexamethasone (CRD) or CTD. For transplant-ineligible patients, there was no difference in VTEs between attenuated CRD (CRDa) and CTDa (10.4% [n = 95 of 916] vs 10.7% [n = 97 of 910]; aHR, 0.97; 95% CI, 0.73-1.29). However, arterial risk was higher with CRDa than with CTDa (3.1% [n = 28 of 916] vs 1.6% [n = 15 of 910]; aHR, 1.91; 95% CI, 1.02-3.57). Thrombotic events occurred almost entirely within 6 months of treatment initiation. Thrombosis was not associated with inferior progression-free survival (PFS) or overall survival (OS), apart from inferior OS for patients with arterial events (aHR, 1.53; 95% CI, 1.12-2.08) in Myeloma XI. The Myeloma XI trial protocol incorporated International Myeloma Working Group (IMWG) thrombosis prevention recommendations and compared with Myeloma IX, more patients received thromboprophylaxis (80.5% vs 22.3%) with lower rates of VTE for identical regimens (CTD, 13.2% vs 16.1%; CTDa, 10.7% vs 16.0%). However, thrombosis remained frequent in spite of IMWG-guided thromboprophylaxis, suggesting that new approaches are needed.

Evolution of diagnostic workup and treatment for multiple myeloma 2013-2019

OBJECTIVE

To evaluate changes in diagnostic and therapeutic approach in multiple myeloma among Norwegian hematologists in the current decade.

METHODS

This nationwide study in Norway is based on results of surveys conducted among professionally active hematologists from 2013 to 2019. Every year, respondents participating in the survey suggested treatment regimens used in typical clinical situations in patients with multiple myeloma, as well as diagnostic routines.

RESULTS

The use of regimens containing alkylators and thalidomide was common at the beginning of the studied period. Later, lenalidomide became the most preferred treatment in most first-line patients. Bortezomib maintained a stable position in the treatment of myeloma in patients with renal insufficiency. The lenalidomide, bortezomib, and dexamethasone combination became the preferred frontline triplet for transplant-ineligible patients and induction therapy before transplant. Nowadays, the relapse after lenalidomide-based treatment is managed using both bortezomib-based therapies and combinations with the newest agents. Together with the therapeutic landscape, the use of diagnostic criteria and workup as well as supportive care changed in the period influenced by local and international guidelines and recommendations.

CONCLUSION

Norwegian hematologists gradually adopt new clinical concepts, guidelines, and recommendations in their practice.

Maintenance Strategies Post-Autologous Stem Cell Transplantation for Newly Diagnosed Multiple Myeloma

Multiple myeloma, the second most common hematological malignancy worldwide, has demonstrated dramatic improvements in outcome in the last decade. In newly diagnosed patients, induction chemotherapy followed by autologous stem cell transplantation (ASCT) is the standard of care. After ASCT, the majority of patients experience disease remission but, despite recent therapeutic developments, most will eventually relapse. In this review we consider clinical aspects of maintenance therapies that can be used post-ASCT to prolong remission duration. We discuss the evidence for the effectiveness of each of these drugs as a maintenance therapy, alongside other benefits and drawbacks to their use, for example, route of administration and potential toxicities. We discuss questions which remain unanswered around the optimal use of currently available maintenance therapies and review newer agents being considered for use as maintenance such as emerging immunotherapies.

Risk adapted post-transplant maintenance in multiple myeloma

INTRODUCTION

The survival of multiple myeloma patients is increasing due to new medications, the widespread implementation of autologous stem cell transplantation and better supportive treatments. The controversy surrounding post-transplant treatment is debated due to a lack of large randomized trials comparing the different treatment modalities. The questions for each proposed treatment are whether it improves outcomes, has low cumulative toxicities and is easy to administer. Areas covered: In this review, we have summarized the current data on maintenance therapy in newly diagnosed MM patients undergoing ASCT, focusing on bortezomib, thalidomide and lenalidomide as well as newer agents Expert opinion: Maintenance treatment has been shown to deepen and prolong responses and increase PFS and OS. Lenalidomide is approved for maintenance and guidelines recommend its use post ASCT. Ixazomib has recently been reported to improve PFS.

Mechanism of Action and Novel IMiD-Based Compounds and Combinations in Multiple Myeloma

Over the last 2 decades, thalidomide analogs have induced significant antimyeloma effects via immune-modulation, antiangiogenesis and antiproliferative effects. While the exact molecular mechanism of the targets or the mediators of thalidomide activity were not known, a seminal discovery of cereblon as a thalidomide-binding protein led to explaining the mechanistic basis of antimyeloma activity for this class of agents. Identification of the mechanisms of resistance for immunomodulatory agents (IMiDs), which will have significant clinical implications, remains poorly understood. Newer cereblon modulators with differential effects and improved increased efficacy in cell lines resistant to the current IMiDs are in development with encouraging preclinical data. In this review, we have summarized the mechanisms of action of IMiDs, clinical development, and potential mechanisms of resistance. We also describe novel IMiD-based combinations and the newer cereblon modulators as well.

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.

Blockade of HSP70 by VER-155008 synergistically enhances bortezomib-induced cytotoxicity in multiple myeloma

Proteasome inhibitor bortezomib is one of the most effective drugs currently available for the treatment of multiple myeloma (MM). However, the intrinsic and acquired resistance to bortezomib can limit its effectiveness. The activation of heat shock response has been characterized as a potential resistance mechanism protecting MM cells from bortezomib-induced cell death. In this study, in response to bortezomib therapy, we discovered that HSP70 is one of the most substantially upregulated heat shock proteins. In order to further explore approaches to sensitizing bortezomib-based treatment for MM, we investigated whether targeting HSP70 using a specific inhibitor VER-155008 combined with bortezomib could overcome the acquired resistance in MM. We found that HSP70 inhibitor VER-155008 alone significantly decreased MM cell viability. Moreover, the combination of VER-155008 and bortezomib synergistically induced MM cell apoptosis markedly in vitro. Notably, the combined treatment was found to increase the cleavage of PARP, an early marker of chemotherapy-induced apoptosis. Importantly, the reduction of anti-apoptotic Bcl-2 family member Bcl-2, Bcl-xL, and Mcl-1 and the induction of pro-apoptotic Bcl-2 family member BH3-only protein NOXA and Bim were confirmed to be tightly associated with the synergism. Finally, the ER stress marker CHOP (CCAAT-enhancer binding protein homologous protein), which can cause transcriptional activation of genes involved in cell apoptosis, was markedly induced by both VER-155008 and bortezomib. Taken together, our finding of a strong synergistic interaction between VER-155008 and bortezomib may support for combination therapy in MM patients in the future.

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.

Maintenance therapy and need for cessation studies in multiple myeloma: Focus on the future

With ten years of follow-up since the advent of the modern paradigm of combination induction therapy, consolidative autologous stem-cell transplant, and lenalidomide maintenance, median survival for multiple myeloma has increased to almost 50% at 10 years. Given this outlook, the overarching goal of maintenance therapy is to spare patients from the toxicities of aggressive or otherwise intrusive therapies while ideally extending survival or, at the least, extending progression-free survival or time until next treatment. This review will focus on the current landscape of maintenance therapies for multiple myeloma. The historical context and evidence for choice of agent, duration of treatment, and current strategies and ongoing trials will be discussed - as well as a focus on unmet needs. The case for studies investigating cessation of therapy and risk and response-adapted approaches will be underscored given that the current paradigm likely results in overtreatment for some patients.

Immunomodulatory drugs in the treatment of multiple myeloma

The prognosis of multiple myeloma was quite poor in the last century, but it has significantly improved with the incorporation of novel agents, immunomodulatory drugs (IMiDs) and proteasome inhibitors. Thalidomide was first developed as a sedative in 1950s, but it was withdrawn from the market because of teratogenicity. In 1990s, however, thalidomide received attention due to the discovery of its anticancer potential derived from antiangiogenic and immunomodulatory activities, and its therapeutic effect on myeloma. In 2006, the U.S. Food and Drug Administration approved the use of thalidomide under strict control for the treatment of multiple myeloma. After that, two new IMiDs, lenalidomide and pomalidomide, were developed for the sake of more antitumor activity and less adverse events than thalidomide. The molecular mechanism of action of IMiDs remained unclear for a long time until 2010 when the protein cereblon (CRBN) was identified as a primary direct target. IMiDs binds to CRBN and alters the substrate specificity of the CRBN E3 ubiquitin ligase complex, resulting in breakdown of intrinsic downstream proteins such as IKZF1 (Ikaros) and IKZF3 (Aiolos). There are many clinical trials of multiple myeloma using IMiDs under various conditions, and most of them show the efficacy of IMiDs. Nowadays lenalidomide plays a central role in both newly diagnosed and relapsed/refractory settings, mainly in combination with other novel agents such as proteasome inhibitors and monoclonal antibodies. This review presents an overview of recent advances in immunomodulatory drugs in the treatment of multiple myeloma.

Tandem Autologous-Autologous versus Autologous-Allogeneic Hematopoietic Stem Cell Transplant for Patients with Multiple Myeloma: Long-Term Follow-Up Results from the Blood and Marrow Transplant Clinical Trials Network 0102 Trial

Allogeneic hematopoietic cell transplant (HCT) may improve long-term multiple myeloma (MM) control through the graft-versus-myeloma effect. The Blood and Marrow Transplant Clinical Trials Network 0102 trial was a biologic assignment trial comparing tandem autologous transplant (auto-auto) versus autologous followed by reduced-intensity allogeneic (auto-allo) transplant in patients with newly diagnosed MM with standard-risk (n = 625) or high-risk (n = 85; β₂-microglobulin at diagnosis ≥ 4 mg/dL or deletion of chromosome 13 by conventional karyotyping) disease. Although the initial 3-year analysis showed no difference in progression-free survival (PFS) between arms in either risk group, we hypothesized that long-term follow-up may better capture the impact of the graft-versus-myeloma effect. Median follow-up of survivors was over 10 years. Among standard-risk patients there was no difference in PFS (hazard ratio [HR], 1.11; 95% confidence interval [CI], .93 to 1.35; P = .25) or OS (HR, 1.03; 95% CI, .82 to 1.28; P = .82). The 6-year PFS was 25% in the auto-auto arm versus 22% in the auto-allo arm (P = .32), and 6-year overall survival (OS) was 60% and 59%, respectively (P = .85). In the high-risk group, although there was no statistically significant difference in PFS (HR, .66; 95% CI, .41 to 1.07; P = .07) and OS (HR, 1.01; 95% CI, .60 to 1.71; P = .96), a reduction in 6-year risk of relapse of 77% versus 47% (P = .005) was reflected in better PFS of 13% versus 31% (P = .05) but similar OS, at 47% versus 51% (P = .69). Allogeneic HCT can lead to long-term disease control in patients with high-risk MM and needs to be explored in the context of modern therapy.

Stem-cell transplantation in multiple myeloma: how far have we come?

High-dose therapy (HDT) and autologous stem-cell transplantation (ASCT) has historically been an essential part of multiple myeloma (MM) management since early studies demonstrated its efficacy in relapsed disease, and subsequent phase III trials demonstrated better responses and improved survival with this modality compared with standard chemotherapy. With further advances in the MM treatment landscape, including the development of potent novel agents, there has been an increasing debate around various aspects of ASCT, including the optimal timing, role of single versus tandem ASCT, and the practice of consolidation and maintenance therapy post-ASCT. Routine incorporation of the novel agents at each of the treatment phases, induction, consolidation when used, and maintenance has led to better responses as reflected by increasing rates of minimal residual disease (MRD) negativity, longer progression-free survival (PFS) with improvement in overall survival (OS) and in some of the trials. The phase III trials over the last decade have provided significant clarity on the current approach, and have raised important questions regarding the applicability of this modality in all patients. This review aims to summarize the latest literature in the field and discusses how these findings impact the practice of ASCT today.