Prognostic impact of MYD88 and CXCR4 mutations assessed by droplet digital polymerase chain reaction in IgM monoclonal gammopathy of undetermined significance and smouldering Waldenström macroglobulinaemia.

Waldenström macroglobulinaemia (WM) is characterized by recurrent somatic mutations in MYD88 and CXCR4 genes. However, limitations arise when analysing these mutations in IgM monoclonal gammopathy of undetermined significance (MGUS) or smouldering WM (SWM) given the lower tumour load. Here, we used droplet digital polymerase chain reaction (ddPCR) to analyse MYD88 L265P and CXCR4 S338* mutations (C1013G and C1013A) in unsorted bone marrow (BM) or cell-free DNA (cfDNA) samples from 101 IgM MGUS and 69 SWM patients. ddPCR was more sensitive to assess MYD88 L265P compared to allele-specific PCR, especially in IgM MGUS (64% vs 39%). MYD88 mutation burden correlated with other laboratory biomarkers, particularly BM infiltration (r = 0.8; p < 0.001). CXCR4 C1013G was analysed in MYD88-mutated samples with available genomic DNA and was detected in 19/54 (35%) and 18/42 (43%) IgM MGUS and SWM cases respectively, also showing correlation with BM involvement (r = 0.9; p < 0.001). ddPCR also detected 8 (38%) and 10 (63%) MYD88-mutated cfDNA samples in IgM MGUS and SWM respectively. Moreover, high BM mutation burden (≥8% MYD88 and ≥2% CXCR4) was associated with an increased risk of progression to symptomatic WM. We show the clinical applicability of ddPCR to assess MYD88 and CXCR4 in IgM MGUS and SWM and provide a molecular-based risk classification.

Real-world data on survival improvement in patients with multiple myeloma treated at a single institution over a 45-year period.

The prognostic landscape of multiple myeloma (MM) has evolved significantly over the last few decades. There are, however, few data measuring such improvement in real-world patients. This study aimed to investigate trends in survival improvement over 45 years, and the associated clinical factors, in an unselected population of patients with MM. Between 1970 and 2015, 1 161 MM patients were included. Patients were classified into three calendar periods (1970-1984, 1985-1999, and 2000-2015), according to the treatment received; polychemotherapy, autologous stem cell transplantation, and novel drugs respectively. We analysed relative survival (RS) to accurately evaluate MM-related death rates after excluding the mortality expected in the general population. RS at five years increased from 27% in 1970-1984 to 38% and 56% in the next two calendar periods respectively. The improvement to survival was greater in the younger population, but it was also observed in elderly patients and those with poor performance status and more advanced disease. Although myeloma is still a non-curable disease, encouraging results have been observed in the last decades. Progress is expected to continue with the use of new generations of anti-myeloma drugs, and will, hopefully, be documented in real-world patients by the appropriate population-based studies.

Health-related quality of life in patients with light chain amyloidosis treated with bortezomib, cyclophosphamide, and dexamethasone ± daratumumab: Results from the ANDROMEDA study.

In the phase 3 ANDROMEDA trial, patients treated with daratumumab, bortezomib, cyclophosphamide, and dexamethasone (D-VCd) had significantly higher rates of organ and hematologic response compared with patients who received VCd alone. Here, we present patient-reported outcomes (PROs) from the ANDROMEDA trial. PROs were assessed through cycle 6 using three standardized questionnaires. Treatment effect through cycle 6 was measured by a repeated-measures, mixed-effects model. The magnitude of changes in PROs versus baseline was generally low, but between-group differences favored the D-VCd group. Results were generally consistent irrespective of hematologic, cardiac, or renal responses. More patients in the D-VCd group experienced meaningful improvements in PROs; median time to improvement was more rapid in the D-VCd group versus the VCd group. After cycle 6, patients in the D-VCd group received daratumumab monotherapy and their PRO assessments continued, with improvements in health-related quality of life (HRQoL) reported through cycle 19. PROs of subgroups with renal and cardiac involvement were consistent with those of the intent-to-treat population. These results demonstrate that the previously reported clinical benefits of D-VCd were achieved without decrement to patients' HRQoL and provide support of D-VCd in patients with AL amyloidosis.

Pomalidomide-dexamethasone for treatment of soft-tissue plasmacytomas in patients with relapsed / refractory multiple myeloma.

OBJECTIVE: The presence of plasmacytomas (Ps) in patients with multiple myeloma (MM) is associated with a poor outcome, both in patients treated conventionally and in patients treated with novel agents. Two types of plasmacytomas have being recognized: paraskeletal plasmacytomas (PPs) and extramedullary plasmacytomas (EMPs), being the incidence of EMPs lower but with worse prognosis. Our aim has been to analyze the efficacy of the pomalidomide-dexamethasone combination in this patient profile. METHOD: In the present study, the efficacy of pomalidomide and dexamethasone in 21 patients from nine hospitals of Catalonia (Spain), with relapsed or refractory MM and Ps, was analyzed. For this purpose, we describe the evolution of paraprotein in serum and urine and the size of plasmacytomas during treatment with pomalidomide-dexamethasone. RESULTS: While 34% of the patients achieved a paraprotein response, only two patients with PPs (9%) responded (RC and PR). There were no responses among patients with EMPs. The median progression-free survival from the start of treatment with pomalidomide/dexamethasone was only 1.7 months and the median overall survival of 4.5 months. CONCLUSION: In conclusion, pomalidomide and dexamethasone has limited efficacy in patients with advanced MM and soft-tissue plasmacytomas.

High-risk cytogenetics and persistent minimal residual disease by multiparameter flow cytometry predict unsustained complete response after autologous stem cell transplantation in multiple myeloma.

The achievement of complete response (CR) after high-dose therapy/autologous stem cell transplantation (HDT/ASCT) is a surrogate for prolonged survival in multiple myeloma; however, patients who lose their CR status within 1 year of HDT/ASCT (unsustained CR) have poor prognosis. Thus, the identification of these patients is highly relevant. Here, we investigate which prognostic markers can predict unsustained CR in a series of 241 patients in CR at day +100 after HDT/ASCT who were enrolled in the Spanish GEM2000 (n = 140) and GEM2005 < 65y (n = 101) trials. Twenty-nine (12%) of the 241 patients showed unsustained CR and a dismal outcome (median overall survival 39 months). The presence of baseline high-risk cytogenetics by FISH (hazard ratio 17.3; P = .002) and persistent minimal residual disease by multiparameter flow cytometry at day +100 after HDT/ASCT (hazard ratio 8.0; P = .005) were the only independent factors that predicted unsustained CR. Thus, these 2 parameters may help to identify patients in CR at risk of early progression after HDT/ASCT in whom novel treatments should be investigated.

Superiority of bortezomib, thalidomide, and dexamethasone (VTD) as induction pretransplantation therapy in multiple myeloma: a randomized phase 3 PETHEMA/GEM study.

The Spanish Myeloma Group conducted a trial to compare bortezomib/thalidomide/dexamethasone (VTD) versus thalidomide/dexamethasone (TD) versus vincristine, BCNU, melphalan, cyclophosphamide, prednisone/vincristine, BCNU, doxorubicin, dexamethasone/bortezomib (VBMCP/VBAD/B) in patients aged 65 years or younger with multiple myeloma. The primary endpoint was complete response (CR) rate postinduction and post-autologous stem cell transplantation (ASCT). Three hundred eighty-six patients were allocated to VTD (130), TD (127), or VBMCP/VBAD/B (129). The CR rate was significantly higher with VTD than with TD (35% vs 14%, P = .001) or with VBMCP/VBAD/B (35% vs 21%, P = .01). The median progression-free survival (PFS) was significantly longer with VTD (56.2 vs 28.2 vs 35.5 months, P = .01). In an intention-to-treat analysis, the post-ASCT CR rate was higher with VTD than with TD (46% vs 24%, P = .004) or with VBMCP/VBAD/B (46% vs 38%, P = .1). Patients with high-risk cytogenetics had a shorter PFS and overall survival in the overall series and in all treatment groups. In conclusion, VTD resulted in a higher pre- and posttransplantation CR rate and in a significantly longer PFS although it was not able to overcome the poor prognosis of high-risk cytogenetics. Our results support the use of VTD as a highly effective induction regimen prior to ASCT. The study was registered with http://www.clinicaltrials.gov (NCT00461747) and Eudra CT (no. 2005-001110-41).

Increased PVR Expression on Bone Marrow Macrophages May Promote Resistance to TIGIT Blockade in Multiple Myeloma.

PURPOSE: TIGIT blockade in our ex vivo models of bone marrow (BM) reduced the number of malignant plasma cells (PCs) in only half of patients with multiple myeloma (MM). Here we wanted to investigate whether increased expression of TIGIT ligands may inhibit T cell immune response promoting resistance to TIGIT blockade. EXPERIMENTAL DESIGN: We first characterized the number and phenotype of BM macrophages in the different stages of disease by multi-parameter flow cytometry. We assessed the effect of TIGIT ligands on PC survival performing experiments with ex vivo BM model and analyzed changes in gene expression by using Nanostring technology and real-time PCR. RESULTS: Frequency of BM macrophages was significantly decreased in MM which was accompanied by changes in their immunophenotype. Moreover, we found a higher number of malignant PCs in ex vivo BM cells cultured onto PVR and nectin-2 compared to control, suggesting that both ligands may support PC survival. In addition, presence of PVR, but not nectin-2, overcame the therapeutic effect of TIGIT blockade or exogenous IL-2. Furthermore, presence of exogenous IL-2 increased TIGIT expression on both CD4+ and CD8+ T cells and, indirectly, PVR on BM macrophages. Consistently, PVR reduced the number of cytotoxic T cells and promoted a gene signature with reduced effector molecules. CONCLUSIONS: IL-2 induced TIGIT on T cells in the BM where increased PVR expression resulted in cytotoxic T cell inhibition promoting PC survival and resistance to TIGIT blockade.

A Simple Frailty Score Predicts Survival and Early Mortality in Systemic AL Amyloidosis.

Systemic AL amyloidosis is a challenging disease for which many patients are considered frail in daily clinical practice. However, no study has so far addressed frailty and its impact on the outcome of these patients. We built a simple score to predict mortality based on three frailty-associated variables: age, ECOG performance status (<2 vs. ≥2) and NT-proBNP (<8500 vs. ≥8500 ng/L). Four-hundred and sixteen consecutive newly diagnosed patients diagnosed at ten sites from the Spanish Myeloma Group were eligible for the study. The score was developed in a derivation cohort from a referral center, and it was externally validated in a multicenter cohort. Multivariate analysis showed that the three variables were independent predictors of survival. The score was able to discriminate four groups of patients in terms of overall survival and early mortality in both cohorts. Comorbidity was also analyzed with the Charlson comorbidity index, but it did not reach statistical significance in the model. A nomogram was created to easily estimate the mortality risk of each patient at each time point. This score is a simple, robust, and efficient approach to dynamically assess frailty-dependent mortality both at diagnosis and throughout follow-up. The optimal treatment for frail AL amyloidosis patients remains to be determined but we suggest that the estimation of frailty-associated risk could complement current staging systems, adding value in clinical decision-making in this complex scenario.

Outcome of AL amyloidosis after high-dose melphalan and autologous stem cell transplantation: long-term results in a series of 421 patients.

Previous studies have suggested that, in patients with AL amyloidosis treated with high-dose melphalan and autologous stem-cell transplantation (HDM/SCT), the greatest benefit is seen in those patients achieving a hematologic complete response (CR). We analyzed a series of 421 consecutive patients treated with HDM/SCT at a single referral center and compared outcomes for patients with and without CR. Treatment-related mortality was 11.4% overall (5.6% in the last 5 years). By intention-to-treat analysis, the CR rate was 34% and the median event-free survival (EFS) and overall survival (OS) were 2.6 and 6.3 years, respectively. Eighty-one patients died within the first year after HDM/SCT and were not evaluable for hematologic and organ response. Of 340 evaluable patients, 43% achieved CR and 78% of them experienced an organ response. For CR patients, median EFS and OS were 8.3 and 13.2 years, respectively. Among the 195 patients who did not obtain CR, 52% achieved an organ response, and their median EFS and OS were 2 and 5.9 years, respectively. Thus, treatment of selected AL patients with HDM/SCT resulted in a high organ response rate and long OS, even for those patients who did not achieve CR.

Natural history and prognostic impact of oligoclonal humoral response in patients with multiple myeloma after autologous stem cell transplantation: long-term results from a single institution.

The emergence of an oligoclonal humoral response, resulting in the appearance of a different serum M-protein to that observed at diagnosis is a well-recognized event after autologous stem cell transplantation in multiple myeloma in complete response, and it has been considered to be a benign phenomenon. The aim of the present study was to investigate the incidence, biological characteristics and prognostic value of the oligoclonal bands in patients with myeloma who underwent autologous transplantation at our institution in the last 18 years. We proceed with a retrospective systematic review of all serum and urine immunofixation studies performed in the 211 patients with multiple myeloma who underwent melphalan-based autologous transplantation. Oligoclonal bands were observed in 34% of the patients, with a significantly higher prevalence with the use of novel agents versus conventional chemotherapy in induction (63% vs. 22%; P=0.0001). The incidence of oligoclonal bands was most frequent in non-IgG isotype, particularly in light chain only myeloma. The oligoclonal phenomenon was almost exclusive to patients in complete remission compared to other degrees of response (87% vs. 13%; P=0.0001), and lasted for a median of 1.35 years, persisting during follow up in all patients except in those who relapsed. In prognostic terms, the presence of oligoclonality resulted in a significantly longer progression-free and overall survival. Patients with oligoclonal humoral response lasting for more than one year after transplantation had a significantly longer clinical progression-free and overall survival than those with shorter duration (P=0.008 and P=0.0001, respectively), likely reflecting the importance of a robust humoral immune response.

Graded Cardiac Response Criteria for Patients With Systemic Light Chain Amyloidosis.

PURPOSE: Binary cardiac response assessment using cardiac biomarkers is prognostic in light chain amyloidosis. Previous studies suggested four-level cardiac responses using N-terminal prohormone of brain natiuretic peptide improves prognostic prediction. This study was designed to validate graded cardiac response criteria using N-terminal prohormone of brain natiuretic peptide/brain natiuretic peptide. PATIENTS AND METHODS: This retrospective, multicenter study included patients with light chain amyloidosis who achieved at least a hematologic partial response (PR) and were evaluable for cardiac response. Four response criteria were tested on the basis of natriuretic peptide response depth: cardiac complete response (CarCR), cardiac very good partial response (CarVGPR), cardiac PR (CarPR), and cardiac no response (CarNR). Response was classified as best response and at fixed time points (6, 12, and 24 months from therapy initiation). The study primary outcome was overall survival. RESULTS: 651 patients were included. Best CarCR, CarVGPR, CarPR, and CarNR were achieved in 16%, 26.4%, 22.9%, and 34.7% of patients, respectively. Patients in cardiac stage II were more likely to achieve CarCR than patients in cardiac stage IIIA and IIIB (22% v 13.5% v 3.2%; P < .001). A deeper cardiac response was associated with a longer survival (5-year overall survival 93%, 79%, 65%, and 33% for CarCR, CarVGPR, CarPR, and CarNR, respectively; P < .001). Fixed time-point analyses and time-varying covariates Cox regression analysis, to minimize survivorship bias, affirmed the independent survival advantage of deeper cardiac responses. Four-level response performed better than two-level response as early as 12 months from therapy initiation. CONCLUSION: Graded cardiac response criteria allow better assessment of cardiac improvement compared with the traditional binary response system. The study re-emphasizes the importance of early diagnosis, which increases the likelihood of deep cardiac responses.

Hematopoietic stem cell transplantation for multiple myeloma beyond 2010.

Autologous stem cell transplantation (ASCT) is considered the gold standard in the frontline therapy of younger patients with multiple myeloma because it results in higher complete remission (CR) rates and longer event-free survival than conventional chemotherapy. The greatest benefit from ASCT is obtained in patients achieving CR after transplantation, the likelihood of CR being associated with the M-protein size at the time of transplantation. The incorporation of novel agents results in higher pre- and posttransplantation CR rates. Induction with bortezomib-containing regimens is encouraging in patients with poor-risk cytogenetics. However, longer follow-up is required to assess the impact of this increased CR on long-term survival. The results of posttransplantation consolidation/maintenance with new drugs are encouraging. All this indicates that, in the era of novel agents, high-dose therapy should be optimized rather than replaced. Because of its high transplantation-related mortality, myeloablative allografting has been generally replaced by reduced-intensity conditioning (reduced intensity conditioning allogeneic transplantation). The best results are achieved after a debulky ASCT, with a progression-free survival plateau of 25% to 30% beyond 6 years from reduced intensity conditioning allogeneic transplantation. The development of novel reduced-intensity preparative regimens and peri- and posttransplantation strategies aimed at minimizing graft-versus-host disease, and enhancing the graft-versus-myeloma effect are key issues.

Multiple myeloma in serologic complete remission after autologous stem cell transplantation: impact of bone marrow plasma cell assessment by conventional morphology on disease progression.

The current definition of complete remission (CR) in multiple myeloma (MM) requires a negative serum and urine immunofixation (IFE) and <5% bone marrow plasma cells (BMPCs). The aim of this study was to determine the value of BMPCs count by standard microscopic evaluation in patients with MM in serologic CR after autologous stem cell transplantation (ASCT). Thirty-five patients with a median follow-up after ASCT of 7.3 years were studied. The percentage of BMPCs was an independent predictor of progression in multivariate model (hazard ratio 2.02, P = .009). Patients with >1.5% BMPCs (median: 0.8%) after ASCT had an increased risk of progression (P = .016) and a trend toward a shorter survival (P = .195). In conclusion, conventional morphology of bone marrow is a useful and rapid tool as a first step to assess the residual tumor mass in patients with MM in CR after ASCT, and it constitutes a strong predictor for disease progression.

Abnormal serum free light chain ratio in patients with multiple myeloma in complete remission has strong association with the presence of oligoclonal bands: implications for stringent complete remission definition.

The prevalence of an abnormal serum free light chain (FLC) ratio in 34 patients with multiple myeloma in complete response (CR) after hematopoietic stem cell transplantation was studied. Fourteen of 34 patients (41.2%) showed an abnormal FLC ratio. The frequency of abnormal FLC ratio in patients with or without oligoclonal bands was 72.7% versus 26%, respectively (P = .023). The median value of FLC ratio was 2.55 (95% confidence interval, 1.89-3.20) in patients with oligoclonal bands versus 0.87 (95% confidence interval, 0.70-1.04) for those with no oligoclonal bands (P = .011). This is the first report showing that the presence of oligoclonal bands in patients with multiple myeloma in CR frequently results in an abnormal FLC ratio. Because an oligoclonal immune response is associated with a good outcome, our results question the current definition of stringent CR and support that the prognostic impact of oligoclonal bands should be also assessed on multivariate analysis.

Bortezomib, melphalan, and prednisone versus bortezomib, thalidomide, and prednisone as induction therapy followed by maintenance treatment with bortezomib and thalidomide versus bortezomib and prednisone in elderly patients with untreated multiple myeloma: a randomised trial.

BACKGROUND: Bortezomib plus melphalan and prednisone (VMP) is significantly better than melphalan plus prednisone alone for elderly patients with untreated multiple myeloma; however, toxic effects are high. We investigated a novel and less intensive bortezomib-based regimen to maintain efficacy and to reduce toxic effects. METHODS: Between March, 2006, and October, 2008, 260 patients with untreated multiple myeloma, 65 years and older, from 63 Spanish centres, were randomly assigned to receive six cycles of VMP (n=130) or bortezomib plus thalidomide and prednisone (VTP; n=130) as induction therapy, consisting of one cycle of bortezomib twice per week for 6 weeks (1·3 mg/m² on days 1, 4, 8, 11, 22, 25, 29, and 32), plus either melphalan (9 mg/m² on days 1-4) or daily thalidomide (100 mg), and prednisone (60 mg/m² on days 1-4). The first cycle was followed by five cycles of bortezomib once per week for 5 weeks (1·3 mg/m² on days 1, 8, 15, and 22) plus the same doses of melphalan plus prednisone and thalidomide plus prednisone. 178 patients completed the six induction cycles and were randomly assigned to maintenance therapy with bortezomib plus prednisone (n=87) or bortezomib plus thalidomide (n=91), consisting of one conventional cycle of bortezomib for 3 weeks (1·3 mg/m² on days 1, 4, 8, and 11) every 3 months, plus either prednisone (50 mg every other day) or thalidomide (50 mg per day), for up to 3 years. Treatment codes were generated with a computerised random number generator, and neither participants nor study personnel were masked to treatment. The primary endpoint was response rate in induction and maintenance phases. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00443235. FINDINGS: In the induction phase, 105 (81%) patients in the VTP group and 104 (80%) in the VMP group achieved partial responses or better (p=0·9), including 36 (28%) and 26 (20%) complete remissions, respectively (p=0·2). Treatment with VTP resulted in more serious adverse events (40 [31%] vs 20 [15%], p=0·01) and discontinuations (22 [17%] vs 15 [12%], p=0·03) than did treatment with VMP. The most common toxicities (grade 3 or worse) were infections (one [1%] in the VTP group vs nine [7%] in the VMP group), cardiac events (11 [8%] vs 0), and peripheral neuropathy (nine [7%] vs 12 [9%]). After maintenance therapy, the complete remission rate was 42% (40 [44%] patients in complete remission in the bortezomib plus thalidomide group, 34 [39%] in the bortezomib plus prednisone group). No grade 3 or worse haematological toxicities were recorded during maintenance therapy; two (2%) patients in the bortezomib plus prednisone group and six (7%) in the bortezomib plus thalidomide group developed peripheral neuropathy. INTERPRETATION: Reduced-intensity induction with a bortezomib-based regimen, followed by maintenance, is a safe and effective treatment for elderly patients with multiple myeloma. FUNDING: Pethema (Spanish Program for the Treatment of Hematologic Diseases).

Treatment of Patients with Monoclonal Gammopathy of Clinical Significance.

Monoclonal gammopathy of undetermined significance (MGUS) is defined as the presence of a monoclonal protein (M-protein) produced by a small amount of plasma cells. The majority of patients remain asymptomatic; however, a fraction of them develop clinical manifestations related to the monoclonal gammopathy despite not fulfilling criteria of multiple myeloma or other lymphoproliferative disorder. These patients constitute an emerging clinical issue coined as monoclonal gammopathy of clinical significance (MGCS). The mechanisms involved are poorly understood, and literature is scarce regarding management. The clinical spectrum involves symptoms related to renal, neurologic, skin, ocular, or bleeding manifestations, requiring a multidisciplinary approach. Treatment strategies rely on the basis of symptomatic disease and the M-protein isotype. In this review, we focus on MGCS other than renal, as the latter was earliest recognized and better known. We review the literature and discuss management from diagnosis to treatment based on illustrative cases from daily practice.

Impact of response to treatment in health-related quality of life patient-reported outcomes in elderly patients with relapsed multiple myeloma.

Multiple myeloma (MM) is a recurrent malignancy with a high impact on quality of life. Improved survival relies on the combination of drugs and extended duration of therapy, raising concerns on its toxicity burden in elderly patients. Health-related quality of life measurements attent to capture health aspects relevant to patients other than efficacy. This prospective study aimed to understand the relationship between MM-related symptomatology and other quality of life dimensions using the EORTC QLQ-MY20 questionnaire in individuals with relapsed or refractory MM. Irrespective of treatment modality, over 50% of patients who responded to treatment had significant omprovements of reported scores in all domains. Conversely, disease progression was associated with score deterioration not only in the MM-related symptoms domain but also in all other domains. HRQoL adds valuable information to the established efficacy endpoints but an adequate interpretation of HRQoL outcomes in randomized trials should require stratification according to response.

Predictors of return to work after autologous stem cell transplantation in patients with multiple myeloma.

Return to work (RTW) is a marker of functional recovery in cancer patients, with quality of life, financial and social implications. We investigated frequency and factors associated with RTW in a cohort of patients younger than 66 years, with newly diagnosed multiple myeloma (MM), uniformly treated with a bortezomib-based induction followed by autologous stem cell transplantation (ASCT). Socio-economic and working status data were collected by a self-administered questionnaire. One hundred and eighty-six patients entered the study. Of whom, 145 (78%) where employed at diagnosis, which was more frequent in younger (median 55 vs. 60 years, p < 0.001), men (59.3% vs. 34.2%, p = 0.004), and with college studies (44.8% vs. 24.4%, p = 0.008). Forty-three (30%) of the 145 patients who had a job at diagnosis, RTW after ASCT in a median of 5 (range 1-27) months. Factors independently associated with RTW were having three or more children (HR 2.87, 95% CI 1.33-6.18), college studies (HR 2.78, 95% CI 1.21-6.41), and a family income >40 × 103€/year (HR 2.31, 95% CI 1.12-4.78). In conclusion, the frequency of RTW herein reported in MM patients seems lower than reported in other malignancies. The risk factors observed may guide the design RTW programs.

Gene Expression Analysis of the Bone Marrow Microenvironment Reveals Distinct Immunotypes in Smoldering Multiple Myeloma Associated to Progression to Symptomatic Disease.

Background: We previously reported algorithms based on clinical parameters and plasma cell characteristics to identify patients with smoldering multiple myeloma (SMM) with higher risk of progressing who could benefit from early treatment. In this work, we analyzed differences in the immune bone marrow (BM) microenvironment in SMM to better understand the role of immune surveillance in disease progression and to identify immune biomarkers associated to higher risk of progression. Methods: Gene expression analysis of BM cells from 28 patients with SMM, 22 patients with monoclonal gammopathy of undetermined significance (MGUS) and 22 patients with symptomatic MM was performed by using Nanostring Technology. Results: BM cells in SMM compared to both MGUS and symptomatic MM showed upregulation of genes encoding for key molecules in cytotoxicity. However, some of these cytotoxic molecules positively correlated with inhibitory immune checkpoints, which may impair the effector function of BM cytotoxic cells. Analysis of 28 patients with SMM revealed 4 distinct clusters based on immune composition and activation markers. Patients in cluster 2 showed a significant increase in expression of cytotoxic molecules but also inhibitory immune checkpoints compared to cluster 3, suggesting the presence of cytotoxic cells with an exhausted phenotype. Accordingly, patients in cluster 3 had a significantly longer progression free survival. Finally, individual gene expression analysis showed that higher expression of TNF superfamily members (TNF, TNFAIP3, TNFRSF14) was associated with shorter progression free survival. Conclusions: Our results suggest that exhausted cytotoxic cells are associated to high-risk patients with SMM. Biomarkers overexpressed in patients with this immune gene profile in combination with clinical parameters and PC characterization may be useful to identify SMM patients with higher risk of progression.

Defining an Ultra-Low Risk Group in Asymptomatic IgM Monoclonal Gammopathy.

We analyzed 171 patients with asymptomatic IgM monoclonal gammopathies (64 with IgM monoclonal gammopathy of undetermined significance-MGUS and 107 with smoldering Waldenström macroglobulinemia - SWM) who had a bone marrow (BM) evaluation performed at diagnosis. Abnormal free-light chain ratio (53% vs. 31%) and MYD88 mutation prevalence (66% vs. 30%) were higher in patients with SWM. No other differences were found among groups. With a median follow-up of 4.3 years, 14 patients progressed to Waldenström macroglobulinemia, 1 to amyloidosis, and 28 died without progression. The MYD88 mutation was found in 53% of patients (available in 160 patients). Multivariate analysis showed that immunoparesis (subhazard ratio-SHR 10.2, 95% confidence interval-CI: 4.2-24.8; p < 0.001) and BM lymphoplasmacytic infiltration ≥ 20% (SHR: 6, 95% CI: 1.6-22.1; p = 0.007) were associated with higher risk of progression. We developed a risk model based on these two risk factors. In the absence of both variables, an ultra-low risk group was identified (SHR 0.1, 95% CI 0.02-0.5; p = 0.004), with 3% and 6% of cumulative incidence of progression at 10 and 20 years, respectively. Bootstrap analysis confirmed the reproducibility of these results. This study finds immunoparesis and BM infiltration as biomarkers of progression as well as a low-risk group of progression in asymptomatic IgM monoclonal gammopathies.