The introduction of novel agents has led to major improvements in clinical outcomes for patients with multiple myeloma. In order to shorten evaluation times for new treatments, health agencies are currently examining minimal residual disease (MRD) as a surrogate endpoint in clinical trials. We assessed the prognostic value of MRD, measured during maintenance therapy by next-generation sequencing. MRD negativity was defined as the absence of tumor plasma cell within 1,000,000 bone marrow cells (<10^-6). Data were analyzed from a recent clinical trial that evaluated the role of transplantation in newly diagnosed myeloma patients treated with lenalidomide, bortezomib, and dexamethasone (RVD). MRD negativity was achieved at least once during maintenance in 127 patients (25%). At the start of maintenance therapy, MRD was a strong prognostic factor for both progression-free survival (adjusted hazard ratio, 0.22; 95% confidence interval, 0.15 to 0.34; P<0.001) and overall survival (adjusted hazard ratio, 0.24; 95%confidence interval, 0.11 to 0.54; P=0.001). Patients who were MRD negative had a higher probability of prolonged progression-free survival than patients with detectable residual disease, regardless of treatment group (RVD versus transplant), cytogenetic risk profile or international staging system disease stage at diagnosis. These results were similar after completion of maintenance therapy. Our findings confirm the value of MRD status, as determined by next-generation sequencing, as a prognostic biomarker in multiple myeloma, and suggest that this approach could be used to adapt treatment strategies in future clinical trials. Key points MRD using NGS identified patients with an excellent outcome in multiple myeloma. MRD should be assessed in every prospective trial, and is a candidate to become a primary endpoint.

Purpose: The three-drug combination of lenalidomide, bortezomib, and dexamethasone (RVD) has shown significant efficacy in multiple myeloma (MM). The Intergroupe Francophone du Myélome (IFM) decided to evaluate RVD induction and consolidation therapies in a sequential intensive strategy for previously untreated transplantation-eligible patients with MM. Patients and Methods: In this phase II study, 31 symptomatic patients age < 65 years were enrolled to receive three RVD induction cycles followed by cyclophosphamide harvest and transplantation. Patients subsequently received two RVD consolidation cycles and 1-year lenalidomide maintenance. Results: Very good partial response rate or better at the completion of induction, transplantation, and consolidation therapy was 58%, 70%, and 87%, respectively. Maintenance upgraded responses in 27% of patients. Overall, 58% of patients achieved complete response, and 68% were minimal residual disease (MRD) negative by flow cytometry. The most common toxicities with RVD were neurologic and hematologic, including grade 1 to 2 sensory neuropathy (55%), grade 3 to 4 neutropenia (35%), and thrombocytopenia (13%). Two basal cell carcinomas in the same patient and one case of breast cancer were observed. There was no treatment-related mortality. With a median follow-up of 39 months, estimated 3-year progression-free and overall survival were 77% and 100%, respectively. None of the patients who achieved MRD negativity relapsed. Conclusion: The transplantation program with RVD induction and consolidation followed by lenalidomide maintenance produced high-quality responses and showed favorable tolerability in patients with newly diagnosed MM. Overall, 68% of patients achieved MRD negativity; none of these patients relapsed. This program is being evaluated in the ongoing IFM/Dana-Farber Cancer Institute 2009 phase III study.

Despite significant improvements in survival of patients with multiple myeloma (MM), outcomes remain heterogeneous, and a significant proportion of patients experience suboptimal outcomes. Importantly, traditional prognostic factors based on data from patients treated with older therapies no longer capture prognosis accurately in the contemporary era of novel triplet or quadruplet therapies. Therefore, risk stratification requires refinement in the context of available and investigational treatment options in routine practice and clinical trials, respectively. The current identification of high-risk MM (HRMM) in routine practice is based on the Revised International Staging System, which stratifies patients using a combination of widely available serum biomarkers and chromosomal abnormalities assessed via fluorescence in situ hybridization. In recent years, a substantial body of evidence concerning additional clinical, biological, and molecular/genomic prognostic factors has accumulated, along with new MM risk stratification tools and consensus reports. The International Myeloma Society, along with the International Myeloma Working Group, convened an Expert Panel with the primary aim of revisiting the definition of HRMM and formulating a practical and data-driven consensus definition, based on new evidence from molecular/genomic assays, updated clinical data, and contemporary risk stratification concepts. The Panel proposes the following Consensus Genomic Staging (CGS) of HRMM which relies upon the presence of at least one of these abnormalities: (1) del(17p), with a cutoff of >20% clonal fraction, and/or TP53 mutation; (2) an IgH translocation including t(4;14), t(14;16), or t(14;20) along with 1q+ and/or del(1p32); (3) monoallelic del(1p32) along with 1q+ or biallelic del(1p32); or (4) β2 microglobulin ≥5.5 mg/L with normal creatinine (<1.2 mg/dL).