Efficacy of Selinexor in Relapsed/Refractory Multiple Myeloma (RRMM) Patients with del17p and Other High-Risk Abnormalities (A Retrospective Single-Center Study).

Selinexor (Seli) is a first-in-class, oral selective inhibitor of the nuclear export protein, exportin-1 (XPO1). Seli exhibits its antitumor effect through the blockage of XPO1, which increases nuclear retention of tumor suppressor proteins (TSPs), including p53, thereby limiting the translation of oncogenes, triggering cell cycle arrest and the death of malignant cells. Multiple Myeloma (MM) patients with del17p are deficient in TP53 and have a particularly poor prognosis. Given its unique mechanism of action, we investigated whether Seli has increased efficacy in RRMM patients with del17p compared to other high-risk cytogenetics (OHRC). This is an IRB-approved observational study of RRMM patients with high-risk cytogenetics (del17p, t (4;14), t (14;16) or gain 1q) or standard-risk cytogenetics treated at the Levine Cancer Institute (LCI) with a Seli-based regimen between January 2019 and December 2022. Time-to-event endpoints (PFS, OS) were evaluated using Kaplan-Meier (KM) methods. Log-rank tests compared time-to-event endpoints between cohorts [del17p vs. OHRC vs. standard risk]. We identified 40 RRMM patients with high-risk cytogenetics, including 16 patients with del17p and 24 patients with OHRC, as well as 20 with standard-risk cytogenetics. The median age was 62.5 vs. 69 vs. 65.5 years (del17p group vs. OHRC vs. standard risk). The median prior line of therapies was five (range: 3-16) with similar rates of prior autologous stem cell transplant in all arms (68.8% vs. 62.5% vs. 70.0%). The most frequently used regimens were Seli-Pomalidomide-dexamethasone(dex) or Seli-Carfilzomib-dex (Seli-Kd) in the del17p group and Seli-Kd in the OHRC and standard-risk groups. The median time to start the Seli-based regimen after initial MM diagnosis was 5.6 years for the del17p group, 4.1 years in OHRC, and 4.8 years in the standard-risk group. The median follow-up time after the start of the Seli-based regimen was 10.5 months (mos) in the del17p group, 8.4 mos in OHRC, and 10.3 mos in the standard-risk group. In the del17p group, 50% had an objective response, 41.7% in the OHRC, and 35% in the standard-risk group (p = 0.71). Depth of response was also similar across the arms (12.5% vs. 12.5% vs. 10.0% VGPR p = 0.99). The median OS was 10.9 mos in the del17p group, 10.3 mos in the OHRC, and 10.3 mos in the standard-risk group (p = 0.92). The median OS was 15.5 mos for patients who received Seli as a bridging therapy versus 9 mos for Seli use for other reasons rather than as a bridge. Overall, Seli-based regimens showed promising responses even in this heavily pretreated population. Our analysis suggests that Seli-based regimens lead to similar outcomes among RRMM patients with del17p, OHRC, and standard-risk cytogenetics. This contrasts with previously reported outcomes using combinations of novel therapies in this population, where the del17p patients often have a poorer prognosis. Interestingly, our data suggest that Seli is a particularly effective bridging modality for patients preparing for CAR-T cell therapies in our population. Further investigation into this population is warranted, including in earlier lines of therapy, in hopes of seeing a more durable response.

A Clinical and Correlative Study of Elotuzumab, Carfilzomib, Lenalidomide, and Dexamethasone (Elo-KRd) for Lenalidomide Refractory Multiple Myeloma in First Relapse.

INTRODUCTION: Treatment of patients with multiple myeloma (MM) in first relapse remains a challenge. This phase II study combined elotuzumab (Elo) with carfilzomib, lenalidomide, and dexamethasone (KRd) for treatment of MM in first relapse with the aim of improving efficacy. METHODS: Enrolled patients received Elo-KRd induction for 4 cycles, and Elo-lenalidomide maintenance until progression. The primary endpoint was VGPR or better (≥VGPR) postinduction. Secondary endpoints were MRD by flow cytometry, OS, PFS, and safety. Correlatives included characterization of the impact of Elo-KRd on NK and T cell subsets via flow cytometry. Target accrual of 40 patients was not met due to COVID-19 pandemic. RESULTS: Of 15 patients enrolled, 10 (67%) had high-risk features (del17p, t[4;14], t[14;16], 1q gain/amplification, plasma cell leukemia, extramedullary MM, or functional high risk), 12 (80%) were lenalidomide-refractory, and 5 (33.3%) bortezomib-refractory. Postinduction ≥VGPR was 7/15 (46.7%) and MRD-negative (10-5) rate 20%. Overall response during study was 80%, including ≥VGPR as best response of 53.3%. At median follow-up of 28.2 (range, 3.8 to 44.2) months, the median PFS was 11.5 months (95% CI 1.9, 18), and median OS not reached (95% CI 10.1, NA). No new safety concerns were reported. Elo-KRd treatment did not augment NK cell distribution or activity in blood or bone marrow. Effector CD4+ and CD8+ T cells significantly decreased postinduction, with concomitant acquisition of T central memory phenotype, particularly at a high rate in ≥VGPR group. CONCLUSION: A short course of Elo-KRd induction followed by Elo-lenalidomide maintenance demonstrated activity in predominantly lenalidomide-refractory and / or high-risk MM. The results with this well-tolerated combination are comparable to other contemporary approved triplet combinations.

Tafasitamab and lenalidomide for relapsed/refractory diffuse large B-cell lymphoma in a patient on chronic intermittent hemodialysis.

INTRODUCTION: Tafasitamab is an anti-CD19 monoclonal antibody indicated for the treatment of relapsed/refractory diffuse large B-cell lymphoma to be given in combination with lenalidomide. Experiences with tafasitamab in the setting of hemodialysis are limited and the efficacy and safety of this agent in this setting are unknown. CASE REPORT: We describe a patient with relapsed/refractory diffuse large B-cell lymphoma with hemodialysis-dependent end-stage renal disease who successfully received tafasitamab/lenalidomide. MANAGEMENT AND OUTCOME: Tafasitamab and reduced dose lenalidomide were initiated for relapsed diffuse large B-cell lymphoma. Tafasitamab was administered on non-dialysis days. Follow-up imaging for disease response assessment demonstrated a complete response. Therapy was well tolerated; the only major toxicity experienced was grade 4 neutropenia that resolved with dose adjustment to lenalidomide. Over a year from initiating therapy, the patient remains in a complete response. DISCUSSION/CONCLUSION: The combination of tafasitamab and dose-reduced lenalidomide produced a complete response in the treatment of relapsed/refractory diffuse large B-cell lymphoma in the setting of chronic intermittent hemodialysis.

High-risk myeloma is associated with global elevation of miRNAs and overexpression of EIF2C2/AGO2.

MicroRNAs (miRNAs) are noncoding RNAs that regulate global gene expression. miRNAs often act synergistically to repress target genes, and their dysregulation can contribute to the initiation and progression of a variety of cancers. The clinical relationship between global expression of miRNA and mRNA in cancer has not been studied in detail. We used whole-genome microarray analyses of CD138-enriched plasma cells from 52 newly diagnosed cases of multiple myeloma to correlate miRNA expression profiles with a validated mRNA-based risk stratification score, proliferation index, and predefined gene sets. In stark contrast to mRNAs, we discovered that all tested miRNAs were significantly up-regulated in high-risk disease as defined by a validated 70-gene risk score (P < 0.01) and proliferation index (P < 0.05). Increased expression of EIF2C2/AGO2, a master regulator of the maturation and function of miRNAs and a component of the 70-gene mRNA risk model, is driven by DNA copy number gains in MM. Silencing of AGO2 dramatically decreased viability in MM cell lines. Genome-wide elevated expression of miRNAs in high-risk MM may be secondary to deregulation of AGO2 and the enzyme complexes that regulate miRNA maturation and function.

Seven-year median time to progression with thalidomide for smoldering myeloma: partial response identifies subset requiring earlier salvage therapy for symptomatic disease.

Smoldering multiple myeloma (SMM) is usually followed expectantly without therapy. We conducted a phase 2 trial in 76 eligible patients with SMM, combining thalidomide (THAL, 200 mg/d) with monthly pamidronate. In the first 2 years, THAL dose reduction was required in 86% and drug was discontinued in 50%. Within 4 years, 63% improved, including 25% qualifying for partial response (PR); by then, 34 patients had progressed and 17 required salvage therapy. Unexpectedly, attaining PR status was associated with a shorter time to salvage therapy for disease progression (P < .001), perhaps reflecting greater drug sensitivity of more aggressive disease. Low beta-2-microglobulin levels less than 2 mg/L were independently associated with superior overall and event-free survival. Four-year survival and event-free survival estimates of 91% and 60%, respectively, together with a median postsalvage therapy survival of more than 5 years justify the conduct of a prospective randomized clinical trial to determine the clinical value of preemptive therapy in SMM. Trial registered at http://www.clinicaltrials.gov under identifier NCT00083382.

Thalidomide arm of Total Therapy 2 improves complete remission duration and survival in myeloma patients with metaphase cytogenetic abnormalities.

Total Therapy 2 examined the clinical benefit of adding thalidomide up-front to a tandem transplant regimen for newly diagnosed patients with multiple myeloma. When initially reported with a median follow-up of 42 months, complete response rate and event-free survival were superior among the 323 patients randomized to thalidomide, whereas overall survival was indistinguishable from that of the 345 patients treated on the control arm. With further follow-up currently at a median of 72 months, survival plots segregated 5 years after initiation of therapy in favor of thalidomide (P = .09), reaching statistical significance for the one third of patients exhibiting cytogenetic abnormalities (CAs; P = .02), a well-recognized adverse prognostic feature. The duration of complete remission was also superior in the cohort presenting with CAs such that, at 7 years from onset of complete remission, 45% remained relapse-free as opposed to 20% on the control arm (P = .05). These observations were confirmed when examined by multivariate analysis demonstrating that thalidomide reduced the hazard of death by 41% among patients with CA-positive disease (P = .008). Because two thirds of patients without CAs have remained alive at 7 years, the presently emerging separation in favor of thalidomide may eventually reach statistical significance as well.

Complete remission sustained 3 years from treatment initiation is a powerful surrogate for extended survival in multiple myeloma.

BACKGROUND: Complete response (CR) has been considered a necessary although not sufficient early clinical endpoint for extended survival in multiple myeloma. METHODS: By using Total Therapy 2 (TT2) clinical outcome data in 668 patients, whether sustained CR (SUS-CR) was potentially a superior surrogate for survival than attaining CR status per se was evaluated. RESULTS: Compared with not achieving CR (NON-CR) and especially achieving and subsequently losing CR status (LOS-CR) within a 3-year landmark from treatment initiation, SUS-CR was associated with highly superior postlandmark survival (P < .0001). These results were validated in 231 untreated patients enrolled in the predecessor trial, TT1 (hazard ratio [HR] = 0.54, P = .013) and in 1103 previously treated patients on other transplant protocols (HR = 0.49; P < .001). CONCLUSIONS: In all 3 trial settings the survival benefit of SUS-CR was independent of metaphase abnormalities as a dominant adverse parameter. Given its bleak prognosis despite high CR rates, SUS-CR should be evaluated as a primary trial endpoint in high-risk myeloma.

Completion of premaintenance phases in total therapies 2 and 3 improves clinical outcomes in multiple myeloma: an important variable to be considered in clinical trial designs.

BACKGROUND: Total Therapy (TT) programs are complex and their execution over the course of several years is fraught with patient attrition due to failure and toxicity of therapy and patient/physician acceptance. METHODS: The impact of completion versus noncompletion of intended treatment steps was examined in protocols TT2 (n=668) and TT3 (n=303) on overall survival (OS) and event-free survival (EFS). RESULTS: By using appropriate landmarks of 36 months with TT2 and 18 months with TT3, representing the maxima to completion of premaintenance phases, postconsolidation OS was superior for 211 patients completing versus 311 patients not completing premaintenance steps on TT2 (P=.001), which also pertained to the 161 patients completing versus 47 not completing intended treatment steps on TT3 (P=.01). On multivariate analysis that included all patients, completion of therapy independently favored longer OS and EFS in the context of both standard prognostic factors and gene expression profiling-defined risk; in addition, TT3 prolonged EFS over results obtained with TT2. CONCLUSIONS: 1) Completion of intended therapy was a significant independent variable conferring superior OS and EFS in TT programs; and 2) after adjusting for completion of therapy, EFS was still superior with TT3 versus TT2, supporting the beneficial role of bortezomib included in TT3. Collectively, these data point to the importance of designing clinical trials that balance the treatment requirements for disease control with host acceptance and tolerance.

Eight-year median survival in multiple myeloma after total therapy 2: roles of thalidomide and consolidation chemotherapy in the context of total therapy 1.

In comparison to total therapy 1 (TT1), the phase 3 trial total therapy 2 (TT2) evaluated the benefit of up-front administration of thalidomide (THAL); TT2 also introduced post-transplant consolidation chemotherapy. With median follow-up times of 5 and 12 years, respectively, outcome comparisons were made of 668 patient's enrolled on TT2 and 231 patients treated on TT1. Complete response (CR) rates were similar at 40% for TT1 and TT2 without THAL versus 60% on the THAL arm of TT2. CR durations were similar with either TT2 arm and both were superior to results of TT1. Event-free and overall survivals were extended from 2.6 to 5.7 years, respectively, with TT1 to 4.8 and 8.0 years with TT2. TT2's major advance vis-à-vis TT1 pertained to the subgroup without cytogenetic abnormalities (CA), supporting the role of post-transplant consolidation therapy, whereas the improved survival of the CA subgroup on the experimental versus control arm of TT2 attests to the role of THAL in this setting. Adjusting for prognostic variables in multivariate and pair-mate analyses, TT2 was superior to TT1 in terms of CR duration, event-free and overall survival. These results provide a basis for the prospective evaluation of the consolidation strategy in a randomized clinical trial design.

Sustained complete remissions in multiple myeloma linked to bortezomib in total therapy 3: comparison with total therapy 2.

Total therapy 3 (TT3), incorporating bortezomib up-front into a tandem transplant regimen for newly diagnosed multiple myeloma (MM), effected 2-year complete response (CR) estimates >90%, which appeared superior to results reported for total therapy 2 (TT2). With median follow-up times of 2 years with TT3 and 5 years with TT2, the clinical outcomes of 303 patients in the former and 668 in the latter trial were compared, including the subset of 607 patients with gene expression profiling (GEP) data. With similar baseline prognostic factors, event-free survival (EFS) (P = 0.0002) and CR duration (P = 0.003) were superior with TT3 vs. TT2 with a strong trend noted also for improved overall survival (OS) (P = 0.16). In the GEP-defined FGFR3 subgroup, TT3 imparted significantly superior OS, EFS and CR duration vis-à-vis TT2. Matching 300 patients each by standard prognostic factors, TT3 yielded superior EFS and CR duration and borderline superior OS. The advantage of TT3 still pertained when the comparison was limited to patients who completed TT2 consolidation rapidly within 24 months. Our data strongly suggest that the addition of bortezomib in TT3 was accountable for its superior performance rather than greater compliance with protocol completion as a result of greater dose-density in TT3 vs. TT2.

High-dose melphalan-based autotransplants for multiple myeloma: the Arkansas experience since 1989 in 3077 patients.

BACKGROUND: In this report, the authors describe their collective experience with melphalan-based autotransplants since the inception of their program at the University of Arkansas for Medical Sciences in 1989. METHODS: The authors evaluated the clinical outcomes of 3077 successive patients with multiple myeloma (MM) who underwent at least 1 melphalan-based autotransplantation at the University of Arkansas. Of these, 1078 patients were enrolled on front-line Total Therapy (TT) protocols (TT-P) TT1, TT2, and TT3; 1104 patients were entered on protocols for newly diagnosed or previously treated patients (non-TT-P); and 895 patients were treated off protocol (non-P). RESULTS: The 10-year overall survival (OS) rates after first transplantation were 41%, 19%, and 11% (P< .001) for the TT-P, non-TT-P, and non-P groups, respectively. In the TT-P group, the median OS was 72 months on TT1, was not reached at >or= 7 years on TT2, and was 88% at 2 years on TT3. Among 2683 patients with complete baseline data, absence of hypodiploidy/chromosome 13 deletion, beta-(2)-microglobulin <3.0 mg/L, C-reactive protein <6 mg/L, albumin >or= 3.0 g/dL, and platelet count >or= 100,000/microL all were associated independently with superior OS (P< .001), event-free survival (P< .001), and duration of complete remission (P< .001). CONCLUSIONS: The results from this large, single-institution experience demonstrated that >10-year OS was accomplished in >40% of all patients enrolled on TT-P, whereas such success was observed in only 15% of the remaining patients (including 25% in the presence of all 5 good-risk features). Superior outcomes with protocol-based, primary transplant regimens such as TT-P draw attention to the importance of applying the best available therapies upfront.

Cytogenetically defined myelodysplasia after melphalan-based autotransplantation for multiple myeloma linked to poor hematopoietic stem-cell mobilization: the Arkansas experience in more than 3,000 patients treated since 1989.

Myelodysplastic syndrome (MDS) is a well-recognized complication of chemotherapy for multiple myeloma (MM). Serial bone marrow metaphase examinations were performed for MM restaging in 3,077 patients undergoing high-dose therapy (HDT). MDS-associated cytogenetic abnormalities (MDS-CAs) were observed in 105 of 2,418 patients in whom cytogenetic data were available after HDT. MDS-CAs occurred transiently in 72 patients and on 3 successive occasions (persistent MDS-CAs) in 33 patients, for 10-year estimates of 4% and 2%, respectively; only 21 patients developed overt clinical MDS and 5, acute myeloblastic leukemia (AML). MDS-CA development was linked to lower CD34 yield at collection, longer time interval from MM diagnosis to HDT, older age, and lower platelet recovery after HDT; persistent MDS-CAs were predicted by CD34 yield of less than 3 x 10(6)/kg and need for more than 2 apheresis procedures. Applying a tertile frequency distribution over time to all 105 patients with MDS-CAs, its detection early after HDT was associated with longer time interval from diagnosis and low pre-HDT platelet count (likely resulting from pre-HDT damage), whereas late-onset MDS-CAs were noted among patients treated with Total Therapy 2 and Total Therapy 3 that applied post-HDT consolidation chemotherapy (suggesting possible post-HDT damage). While the risk of MDS-CAs was low and clinical MDS occurred infrequently, monitoring after post-HDT consolidation chemotherapy appears warranted.

The Arkansas approach to therapy of patients with multiple myeloma.

This chapter gives an account of the experience of the Arkansas myeloma program since 1989 with transplant-supported high-dose melphalan, novel agents, and prognostic factors as they relate to standard laboratory features, gene expression profiling, and magnetic resonance imaging (MRI). Incorporation of novel agents and new concepts, such as post-tandem transplant consolidation therapy, has improved the rate and duration of complete response and prolonged event-free and overall survival rates. With Total Therapy 2, median survival exceeds 8 years, while Total Therapy 3 with added bortezomib has sustained complete remissions in more than 90% of patients at 2 years which, when used as a survival surrogate in Total Therapy 2, assured a high 6-year survival rate of 75%. Gene expression profiling identified 15% of patients with very short survival. MRI-defined focal lesions are associated with poor outcome, while their resolution - although slower than the time course of attaining clinical complete remission - conferred superior survival. Representing a frequent source of recurrence, with genetic profiles (in both plasma and stromal cells) distinct from those in random bone-marrow samples, therapeutic efforts are directed at hastening onset and increasing frequency of focal lesion resolution.

Benefit of complete response in multiple myeloma limited to high-risk subgroup identified by gene expression profiling.

EXPERIMENTAL DESIGN: To determine whether the clinical benefit of complete remission (CR) may depend on prognostic subgroups of patients with multiple myeloma. PATIENTS AND METHODS: Newly diagnosed patients with myeloma received a tandem autotransplant regimen. Using multivariate regression analyses, we examined the prognostic implications of time-dependent onset of CR on overall survival and event-free survival in the context of standard prognostic factors (SPF) and gene expression profiling-derived data available for 326 patients. RESULTS: CR benefited patients regardless of risk status when only SPFs were examined. With knowledge of gene array data, a survival (and event-free survival) benefit of CR only pertained to the small high-risk subgroup of 13% of patients (hazard ratio, 0.23; P = 0.001), whereas the majority of patients with low-risk disease had similar survival expectations whether or not CR was achieved (hazard ratio, 0.68; P = 0.128). CONCLUSIONS: Access to gene expression information permitted the recognition of a small very high-risk subgroup of 13% of patients, in whom prolonged survival critically depended on achieving CR. Absence of such benefit in the remainder should lead to a reassessment of clinical trial designs that rely on this end point as a surrogate for long-term prognosis.

Incorporating bortezomib into upfront treatment for multiple myeloma: early results of total therapy 3.

Total therapy 3 incorporated bortezomib into a melphalan-based tandem transplant regimen for 303 newly diagnosed patients with myeloma. Induction chemotherapy prior to and consolidation chemotherapy after transplants each consisted of two cycles of VTD-PACE (bortezomib, thalidomide, dexamethasone and 4-d continuous infusions of cis-platin, doxorubicin, cyclophosphamide, etoposide); 3-year maintenance comprised monthly cycles of VTD in the first and TD in the remaining years. The median age was 59 years (age >64 years, 28%). A minimum of 20 x 10(6) CD34 cells/kg was collected in 87% of patients; 83% completed both transplants, and only 5% suffered a treatment-related death. At 24 months, 83% had achieved near-complete remission, which was sustained in 88% at 2 years from its onset. With a median follow-up of 20 months, 2-year estimates of event-free and overall survival were 84% and 86% respectively. The 44 patients who experienced an event more often had a high-risk gene array profile, cytogenetic abnormalities and indicators of high lactate dehydrogenase, beta-2-microglobulin, creatinine and International Staging System stage. Toxicities of grade > 2 included thrombo-embolic events in 27% and peripheral neuropathy in 12%. Results of this phase-2 study demonstrated that bortezomib could be safely combined with multi-agent chemotherapy, effecting near-complete remission status and 2-year survival rates in more than 80% of patients.

Testing standard and genetic parameters in 220 patients with multiple myeloma with complete data sets: superiority of molecular genetics.

Prognostic models for multiple myeloma have been fraught with tremendous heterogeneity in outcome among subgroups. In the context of Total Therapy 2, a tandem transplant trial for newly diagnosed myeloma, comprehensive information was available in 220 patients on standard prognostic factors (SPF), magnetic resonance imaging (MRI)-defined focal lesions, cytogenetic abnormalities (CA), fluorescence-in-situ-hybridisation (FISH)-derived amplification of chromosome 1q21 (amp1q21) and deletion of 13q14, as well as gene expression profiling (GEP). Five multivariate analysis-based survival models were derived, utilising SPF only (model 1), with progressive addition of CA (model 2), MRI (model 3), FISH (model 4) and GEP (model 5). The R(2) value, a measure of accounting for clinical outcome variability, increased progressively from 18% in model 1 to 38% in model 5. The hazard ratio for overall survival was highest for GEP (3.07, P < 0.001) followed by amp1q21 (1.71, P = 0.05). According to the presence of none (49%), one (35%) or both of these two risk features (16%), 3-year survival decreased progressively from 92% to 78% to 43% (P < 0.0001). Thus, the dominance over other prognostic parameters of molecular genetics justifies the generation of quantitative reverse transcription polymerase chain reaction methodology ('MM genetic kit') for the optimal risk stratification of patients participating in therapeutic trials.

High serum-free light chain levels and their rapid reduction in response to therapy define an aggressive multiple myeloma subtype with poor prognosis.

Serum-free light chain (SFLC) levels are useful for diagnosing nonsecretory myeloma and monitoring response in light-chain-only disease, especially in the presence of renal failure. As part of a tandem autotransplantation trial for newly diagnosed multiple myeloma, SFLC levels were measured at baseline, within 7 days of starting the first cycle, and before both the second induction cycle and the first transplantation. SFLC baseline levels higher than 75 mg/dL (top tertile) identified 33% of 301 patients with higher near-complete response rate (n-CR) to induction therapy (37% vs 20%, P = .002) yet inferior 24-month overall survival (OS: 76% vs 91%, P < .001) and event-free survival (EFS: 73% vs 90%, P < .001), retaining independent prognostic significance for both EFS (HR = 2.40, P = .008) and OS (HR = 2.43, P = .016). Baseline SFLC higher than 75 mg/dL was associated with light-chain-only secretion (P < .001), creatinine level 176.8 microM (2 mg/dL) or higher (P < .001), beta-2-microglobulin 297.5 nM/L (3.5 mg/L) or higher (P < .001), lactate dehydrogenase 190 U/L or higher (P < .001), and bone marrow plasmacytosis higher than 30% (P = .003). Additional independent adverse implications were conferred by top-tertile SFLC reductions before cycle 2 (OS: HR = 2.97, P = .003; EFS: HR = 2.56, P = .003) and before transplantation (OS: HR = 3.31, P = .001; EFS: HR = 2.65, P = .003). Unlike baseline and follow-up analyses of serum and urine M-proteins, high SFLC levels at baseline-reflecting more aggressive disease-and steeper reductions after therapy identified patients with inferior survival.