Minimal residual disease assessment by multiparameter flow cytometry in transplant-eligible myeloma in the EMN02/HOVON 95 MM trial.

Minimal residual disease (MRD) by multiparameter flow cytometry (MFC) is the most effective tool to define a deep response in multiple myeloma (MM). We conducted an MRD correlative study of the EMN02/HO95 MM phase III trial in newly diagnosed MM patients achieving a suspected complete response before maintenance and every 6 months during maintenance. Patients received high-dose melphalan (HDM) versus bortezomib-melphalan-prednisone (VMP) intensification, followed by bortezomib-lenalidomide-dexamethasone (VRd) versus no consolidation, and lenalidomide maintenance. Bone marrow (BM) samples were processed in three European laboratories, applying EuroFlow-based MFC protocols (eight colors, two tubes) with 10-4-10-5 sensitivity. At enrollment in the MRD correlative study, 76% (244/321) of patients were MRD-negative. In the intention-to-treat analysis, after a median follow-up of 75 months, 5-year progression-free survival was 66% in MRD-negative versus 31% in MRD-positive patients (HR 0.39; p < 0.001), 5-year overall survival was 86% versus 69%, respectively (HR 0.41; p < 0.001). MRD negativity was associated with reduced risk of progression or death in all subgroups, including ISS-III (HR 0.37) and high-risk fluorescence in situ hybridization (FISH) patients (HR 0.38;). In the 1-year maintenance MRD population, 42% of MRD-positive patients at pre-maintenance became MRD-negative after lenalidomide exposure. In conclusion, MRD by MFC is a strong prognostic factor. Lenalidomide maintenance further improved MRD-negativity rate.

A longitudinal analysis of chromosomal abnormalities in disease progression from MGUS/SMM to newly diagnosed and relapsed multiple myeloma.

We analyzed variations in terms of chromosomal abnormalities (CA) by fluorescence in situ hybridization (FISH) analysis on purified bone marrow plasma cells throughout the progression from monoclonal gammopathy of undetermined significance/smoldering multiple myeloma (MGUS/SMM) to newly diagnosed MM/plasma cell leukemia (NDMM/PCL) at diagnosis and from diagnostic samples to progressive disease. High risk was defined by the presence of at least del(17p), t(4;14), and/or t(14;16). 1p/1q detection (in the standard FISH panel from 2012 onward) was not available for all patients. We analyzed 139 MM/PCL diagnostic samples from 144 patients, with a median follow-up of 71 months: high-risk CA at diagnosis (MGUS/SMM or NDMM) was present in 28% of samples, whereas 37-39% showed high-risk CA at relapse. In 115 patients with NDMM who evolved to relapsed/refractory MM, we identified 3 different populations: (1) 31/115 patients (27%) with gain of new CA (del13, del17p, t(4;14), t(14;16) or 1q CA when available); (2) 10/115 (9%) patients with loss of a previously identified CA; and (3) 74 patients with no changes. The CA gain group showed a median overall survival of 66 months vs. 84 months in the third group (HR 0.56, 95% CI 0.34-0.92, p = 0.023). Clonal evolution occurs as disease progresses after different chemotherapy lines. Patients who acquired high-risk CA had the poorest prognosis. Our findings highlight the importance of performing FISH analysis both at diagnosis and at relapse.

Autologous haematopoietic stem-cell transplantation versus bortezomib-melphalan-prednisone, with or without bortezomib-lenalidomide-dexamethasone consolidation therapy, and lenalidomide maintenance for newly diagnosed multiple myeloma (EMN02/HO95): a multicentre, randomised, open-label, phase 3 study.

BACKGROUND: The emergence of highly active novel agents has led some to question the role of autologous haematopoietic stem-cell transplantation (HSCT) and subsequent consolidation therapy in newly diagnosed multiple myeloma. We therefore compared autologous HSCT with bortezomib-melphalan-prednisone (VMP) as intensification therapy, and bortezomib-lenalidomide-dexamethasone (VRD) consolidation therapy with no consolidation. METHODS: In this randomised, open-label, phase 3 study we recruited previously untreated patients with multiple myeloma at 172 academic and community practice centres of the European Myeloma Network. Eligible patients were aged 18-65 years, had symptomatic multiple myeloma stage 1-3 according to the International Staging System (ISS), measurable disease (serum M protein >10 g/L or urine M protein >200 mg in 24 h or abnormal free light chain [FLC] ratio with involved FLC >100 mg/L, or proven plasmacytoma by biopsy), and WHO performance status grade 0-2 (grade 3 was allowed if secondary to myeloma). Patients were first randomly assigned (1:1) to receive either four 42-day cycles of bortezomib (1·3 mg/m2 administered intravenously or subcutaneously on days 1, 4, 8, 11, 22, 25, 29, and 32) combined with melphalan (9 mg/m2 administered orally on days 1-4) and prednisone (60 mg/m2 administered orally on days 1-4) or autologous HSCT after high-dose melphalan (200 mg/m2), stratified by site and ISS disease stage. In centres with a double HSCT policy, the first randomisation (1:1:1) was to VMP or single or double HSCT. Afterwards, a second randomisation assigned patients to receive two 28-day cycles of consolidation therapy with bortezomib (1·3 mg/m2 either intravenously or subcutaneously on days 1, 4, 8, and 11), lenalidomide (25 mg orally on days 1-21), and dexamethasone (20 mg orally on days 1, 2, 4, 5, 8, 9, 11, and 12) or no consolidation; both groups received lenalidomide maintenance therapy (10 mg orally on days 1-21 of a 28-day cycle). The primary outcomes were progression-free survival from the first and second randomisations, analysed in the intention-to-treat population, which included all patients who underwent each randomisation. All patients who received at least one dose of study drugs were included in the safety analyses. This study is registered with the EU Clinical Trials Register (EudraCT 2009-017903-28) and ClinicalTrials.gov (NCT01208766), and has completed recruitment. FINDINGS: Between Feb 25, 2011, and April 3, 2014, 1503 patients were enrolled. 1197 patients were eligible for the first randomisation, of whom 702 were assigned to autologous HSCT and 495 to VMP; 877 patients who were eligible for the first randomisation underwent the second randomisation to VRD consolidation (n=449) or no consolidation (n=428). The data cutoff date for the current analysis was Nov 26, 2018. At a median follow-up of 60·3 months (IQR 52·2-67·6), median progression-free survival was significantly improved with autologous HSCT compared with VMP (56·7 months [95% CI 49·3-64·5] vs 41·9 months [37·5-46·9]; hazard ratio [HR] 0·73, 0·62-0·85; p=0·0001). For the second randomisation, the number of events of progression or death at data cutoff was lower than that preplanned for the final analysis; therefore, the results from the second protocol-specified interim analysis, when 66% of events were reached, are reported (data cutoff Jan 18, 2018). At a median follow-up of 42·1 months (IQR 32·3-49·2), consolidation therapy with VRD significantly improved median progression-free survival compared with no consolidation (58·9 months [54·0-not estimable] vs 45·5 months [39·5-58·4]; HR 0·77, 0·63-0·95; p=0·014). The most common grade ≥3 adverse events in the autologous HSCT group compared to the VMP group included neutropenia (513 [79%] of 652 patients vs 137 [29%] of 472 patients), thrombocytopenia (541 [83%] vs 74 [16%]), gastrointestinal disorders (80 [12%] vs 25 [5%]), and infections (192 [30%] vs 18 [4%]). 239 (34%) of 702 patients in the autologous HSCT group and 135 (27%) of 495 in the VMP group had at least one serious adverse event. Infection was the most common serious adverse event in each of the treatment groups (206 [56%] of 368 and 70 [37%] of 189). 38 (12%) of 311 deaths from first randomisation were likely to be treatment related: 26 (68%) in the autologous HSCT group and 12 (32%) in the VMP group, most frequently due to infections (eight [21%]), cardiac events (six [16%]), and second primary malignancies (20 [53%]). INTERPRETATION: This study supports the use of autologous HSCT as intensification therapy and the use of consolidation therapy in patients with newly diagnosed multiple myeloma, even in the era of novel agents. The role of high-dose chemotherapy needs to be reassessed in future studies, in particular in patients with undetectable minimal residual disease after four-drug induction regimens including a monoclonal antiboby combined with an immunomodulatory agent and a proteasome inhibitor plus dexamethasone. FUNDING: Janssen and Celgene.

Minimal residual disease by flow cytometry and allelic-specific oligonucleotide real-time quantitative polymerase chain reaction in patients with myeloma receiving lenalidomide maintenance: A pooled analysis.

BACKGROUND: Minimal residual disease (MRD) is one of the most relevant prognostic factors in patients with multiple myeloma (MM); however, the impact of maintenance therapy on MRD levels remains unclear. Among patients with newly diagnosed MM (NDMM) who received lenalidomide maintenance until they developed disease progression, the role of MRD status as a predictor of progression-free survival (PFS) was evaluated by multiparameter flow cytometry (MFC) and allelic-specific oligonucleotide real-time quantitative polymerase chain reaction (ASO-RQ-PCR) analysis. METHODS: Seventy-three patients with NDMM enrolled in the RV-MM-EMN-441 (clinical trials.gov identifier, NCT01091831) and RV-MM-COOP-0556 (clinicaltrials.gov identifier, NCT01208766; European Myeloma Network EMN02/HO95 MM Trial) phase 3 trials who achieved at least a very good partial response after intensification/consolidation were included. The median patient age was 57 years (interquartile range, 53-61 years), and all patients received lenalidomide maintenance until they developed progression. MRD was evaluated on bone marrow after intensification/consolidation, after 6 courses of maintenance, and every 6 months thereafter until clinical relapse using both ASO-RQ-PCR (sensitivity, 10-5 ) and MFC (sensitivity, from 10-4 to 10-5 ). RESULTS: After intensification/consolidation, 33 of 72 patients (46%) achieved a molecular complete response (m-CR), and 44 of 70 (63%) achieved a flow complete response (flow-CR). Almost 27% of patients who were MRD-positive after consolidation became MRD-negative during maintenance. After a median follow-up of 38 months, PFS was prolonged in patients who achieved negative MRD status during maintenance according to results from both ASO-RQ-PCR analysis (hazard ratio, 0.29; 95% confidence interval, 0.14-0.62; P = .0013) and MFC (hazard ratio, 0.19; 95% confidence interval, 0.09-0.41; P < .001). The impact of negative MRD status on PFS was similar in all subgroups (ASCT and no-ASCT; International Staging System stages I, II, and III; high-risk and standard-risk cytogenetics), and the two techniques were highly correlated. CONCLUSIONS: MRD status is a stronger predictor of PFS than standard risk factors, and lenalidomide maintenance further increases the rate of negative MRD results.

Promises and Pitfalls in the Use of PD-1/PD-L1 Inhibitors in Multiple Myeloma.

In the biology of multiple myeloma (MM), immune dysregulation has emerged as a critical component for novel therapeutic strategies. This dysfunction is due to a reduced antigen presentation, a reduced effector cell ability and a loss of reactive T cells against myeloma, together with a bone marrow microenvironment that favors immune escape. The Programmed Death-1 (PD-1) pathway is associated with the regulation of T cell activation and with the apoptotic pathways of effector memory T cells. Specifically, the binding with PD-1 ligand (PD-L1) on the surface of tumor plasma cells down-regulates T cell-proliferation, thus contributing to the immune escape of tumor cells. In relapsed and/or refractory MM (RRMM) patients, PD-1/PD-L1 blockade was analyzed by using nivolumab, pembrolizumab, and durvalumab. Outcomes with single agents were unsatisfactory, whereas combination strategies with backbone immunomodulatory drugs (IMiDs) suggested a synergistic action in such a complex immunological landscape, even in patients previously refractory to these drugs. Nevertheless, these combinations were also associated with an increased incidence of adverse events. This review aims to analyze the available preclinical and clinical data on the role of PD-1/PD-L1 inhibitors in MM therapy, focusing on available preliminary efficacy and safety data and offering insights for future investigation.

Pharmacokinetic drug evaluation of ixazomib citrate for the treatment of multiple myeloma.

INTRODUCTION: multiple myeloma (MM) is a plasma cell disorder that represents the second most frequent hematologic cancer. Although MM is still an incurable disease, prognosis has improved in the last decades thanks to the introduction of novel agents such as proteasome inhibitors (PIs), immunomodulatory drugs, monoclonal antibodies, and histone deacetylase inhibitors. Areas covered: ixazomib is the first oral PI recently approved by Food and Drug Administration (FDA) and European Medicine Agency (EMA) in combination with lenalidomide and dexamethasone as salvage therapy in MM patients. In this paper, we focus on its pharmacokinetics features, as well as its safety and efficacy in clinical studies. Expert opinion: ixazomib can be considered an oral analogue of bortezomib, with 9.5-day half-life, 58% of oral bioavailability, and a large distribution volume of 543L. These features make it a versatile molecule, potentially useful both in combination and as single agent. Oral route of administration and good efficacy/safety profile are its winning characteristics, providing the rationale for a future role also in the maintenance setting.

Melphalan hydrochloride for the treatment of multiple myeloma.

INTRODUCTION: Multiple myeloma (MM) is an incurable disease characterized by clonal plasma cell proliferation and overproduction of monoclonal paraprotein, hypercalcemia, renal failure, anemia, osteolytic bone lesions, and infections. Melphalan, a nitrogen mustard, is an alkylating agent synthesized in 1953, and it has been used in multiple myeloma therapy for fifty years. Although novel agents have been introduced in the past few decades improving prognosis of the disease, melphalan still maintains a crucial role in the treatment of MM acting both as cytotoxic agent through damage to DNA, and as immunostimulatory drug by inhibiting Interleukin-6, as well as interaction with dendritic cells, and immunogenic effects in tumor microenvironment. Areas covered: This review focuses on available data about melphalan pharmacology and its role in clinical practice. Expert opinion: Melphalan remains crucial in therapy of multiple myeloma because of its good manageability, safety profile, efficacy, and economic sustainability. These characteristics make it pivotal also for new regimens in combination with novel agents.

Salvage therapy in first relapse: a retrospective study in a large patient population with multiple myeloma.

OBJECTIVE: There is no strong evidence to guide therapeutic approach to multiple myeloma (MM) patients who experience first relapse. The treatment choice can be difficult since currently all patients are exposed to novel agents as thalidomide, bortezomib and lenalidomide. METHODS: In this retrospective analysis, we evaluated the best therapeutic sequence, the role of retreatment, and the most beneficial cutoff of first remission in order to choose retreatment, analyzing 476 patients relapsed after first-line therapy. RESULTS: Bortezomib-based regimens upfront followed by lenalidomide-based regimens at first relapse resulted in significantly better second progression-free survival (2ndPFS), PFS2, and overall survival (OS) compared to the opposite sequence. Changing therapy resulted in significantly better 2ndPFS in the whole population, whereas PFS2 was significantly longer only in patients who underwent maintenance therapy. Moreover, until PFS1 was shorter than 27 months, changing therapy at first relapse significantly extended 2ndPFS and PFS2 compared to retreatment, whereas similar outcomes were observed between the two strategies, when PFS1 was longer than 27 months. CONCLUSION: Lacking randomized trials, our study could help to choose the most appropriate therapy algorithm in patients with MM.

Current Phase II investigational proteasome inhibitors for the treatment of multiple myeloma.

INTRODUCTION: The introduction and exploration of novel agents has significantly improved patient outcome in the treatment of multiple myeloma (MM). One such compound, bortezomib, was the first proteasome inhibitor (PI) to be approved as a MM therapeutic. The efficacy and safety data provided by bortezomib usage has provided the basis for the development of a second generation of PIs. AREAS COVERED: This review focuses on PIs that are currently under evaluation in Phase II clinical trials for the treatment of MM. Furthermore, the article summarizes the currently understood mechanisms of action and the available clinical data for its use in MM. EXPERT OPINION: Second generation PIs have demonstrated promising activity in patients with advanced-stage myeloma, including those refractory to bortezomib. It should be noted, however, that their efficacy in upfront settings is currently under investigation. Future PI development should include schedule optimization and the investigation of PIs potential synergistic activity with other anti-myeloma agents.

Pharmacophore modeling technique applied for the discovery of proteasome inhibitors.

INTRODUCTION: The 26S proteasome has many important roles in the biological functions of the cells, and proteasome inhibitors have multiple and complex activities on cells. These compounds can be natural or synthesized. Most synthetic derivatives have been rationally designed, synthesized and optimized to obtain the best selectivity and increase the activity. The design of chemical entities with desired molecular identification, which plays an important role in biological systems, is provided by pharmacophore modeling. Indeed, pharmacophore models can be established either in a ligand-based manner or in a receptor-based manner. AREAS COVERED: The authors discuss the application of pharmacophore modeling techniques to proteasome inhibitors development. Furthermore, the article reviews the classification of the currently discovered proteasome inhibitors where the principal mechanism of action and clinical application are represented. EXPERT OPINION: In the era of new drug development, database of compounds should be thoroughly evaluated with a combination of methods that consider both pharmacophore- and ligand-based virtual screening. The concept of pharmacophore helps to discover new active compounds and to evaluate their activity. The nature of proteasome inhibitor pharmacophore affects the secondary active-site specificity; indeed, increasing specificity decreases the cytotoxicity of the proteasome inhibitors. It is hypothesized that the balanced simultaneous modulation of a few druggable targets may have superior efficacy and fewer side effects than single-target or combination therapies for the treatment of human cancers. The discovery of new compounds should aim to find more active compounds that improve the compliance of patients.

Monoclonal antibodies currently in Phase II and III trials for multiple myeloma.

INTRODUCTION: Despite the introduction of novel agents, such as thalidomide, lenalidomide and bortezomib, multiple myeloma (MM) remains an incurable disease and new therapies are needed. mAbs are a new promising anticancer treatment option. AREAS COVERED: This review will focus on mAbs that are currently under evaluation in Phase II and III clinical trials, as single agent and in combination with established treatment options. EXPERT OPINION: mAbs are a new strategy against MM, and they have demonstrated encouraging results in preclinical models. mAbs have a relatively benign side-effect profile and work synergistically with traditional chemotherapies and with immunomodulatory drugs and proteasome inhibitors.

Pharmacokinetic evaluation of pomalidomide for the treatment of myeloma.

INTRODUCTION: Multiple myeloma (MM) patients who relapse, or become refractory to currently available novel agents, have limited treatment options with poor outcomes. The introductions of the newer proteasome inhibitor carfilzomib and the immunomodulatory agent pomalidomide have provided new treatment strategies within the relapse setting. Pomalidomide, a novel 4-amino derived from thalidomide, was recently introduced for the treatment of MM. In addition to being immune-adjuvant with anti-inflammatory properties, pomalidomide has shown several biological activities that directly and indirectly inhibit MM cells. AREAS COVERED: Herein, the authors review the chemistry, the mechanism of action and the pharmacokinetic properties of pomalidomide. The data reviewed within this article based on the relevant literature pertaining to pomalidomide's Phase I, II and III clinical trials. EXPERT OPINION: Pomalidomide has shown to be a safe and active agent, both alone and in combination with dexamethasone, in heavily pretreated patients. Furthermore, pomalidomide represents an effective treatment option for relapsed/refractory patients. Results from the ongoing trials evaluating the synergistic activity of pomalidomide combined with conventional chemotherapy or novel agents look promising and may prove to be viable treatment options in the future.