Candidate germline biomarkers of lenalidomide efficacy in mantle cell lymphoma: the FIL MCL0208 trial

In the FIL MCL0208 phase III trial, lenalidomide maintenance (LEN) after transplantation (ASCT) in mantle cell lymphoma (MCL) improved progression-free survival (PFS) vs observation (OBS). The host pharmacogenetic background was analyzed to decipher whether single nucleotide polymorphisms (SNPs) of genes encoding transmembrane transporters, metabolic enzymes, or cell surface receptors might predict drug efficacy. Genotypes were obtained by real-time polymerase chain reaction (RT-PCR) in peripheral blood (PB) germ line DNA. Polymorphisms of either ABCB1 or VEGF were found in 69% and 79% of 278 patients and predicted favorable PFS vs homozygous wild type (WT) in the LEN arm: 3-year PFS 85% vs 70% (p < 0.05) and 85% vs 60% (p < 0.01), respectively. Patients carrying both ABCB1 and VEGF WT had the poorest 3-year PFS (46%) and overall survival (OS, 76%): in fact, in these patients LEN did not improve PFS vs OBS (3-year PFS 44% vs 60%, p = 0.62). Moreover, CRBN polymorphism (n = 28) was associated with lenalidomide dose reduction or discontinuation. Finally, ABCB1, NCF4, and GSTP1 polymorphisms predicted lower hematological toxicity during induction, while ABCB1 and CRBN polymorphisms predicted lower risk of grade ≥3 infections. This study demonstrates that specific SNPs represent candidate predictive biomarkers of immunochemotherapy toxicity and LEN efficacy after ASCT in MCL. This trial is registered at eudract.ema.europa.eu as 2009-012807-25.

Punctual and kinetic MRD analysis from the Fondazione Italiana Linfomi MCL0208 phase 3 trial in mantle cell lymphoma

Minimal residual disease (MRD) analysis is a known predictive tool in mantle cell lymphoma (MCL). We describe MRD results from the Fondazione Italiana Linfomi phase 3 MCL0208 prospective clinical trial assessing lenalidomide (LEN) maintenance vs observation after autologous stem cell transplantation (ASCT) in the first prospective comprehensive analysis of different techniques, molecular markers, and tissues (peripheral blood [PB] and bone marrow [BM]), taken at well-defined time points. Among the 300 patients enrolled, a molecular marker was identified in 250 (83%), allowing us to analyze 234 patients and 4351 analytical findings from 10 time points. ASCT induced high rates of molecular remission (91% in PB and 83% in BM, by quantitative real-time polymerase chain reaction [RQ-PCR]). Nevertheless, the number of patients with persistent clinical and molecular remission decreased over time in both arms (up to 30% after 36 months). MRD predicted early progression and long-term outcome, particularly from 6 months after ASCT (6-month time to progression [TTP] hazard ratio [HR], 3.83; P < .001). In single-timepoint analysis, BM outperformed PB, and RQ-PCR was more reliable, while nested PCR appeared applicable to a larger number of patients (234 vs 176). To improve MRD performance, we developed a time-varying kinetic model based on regularly updated MRD results and the MIPI (Mantle Cell Lymphoma International Prognostic Index), showing an area under the ROC (Receiver Operating Characteristic) curve (AUROC) of up to 0.87 using BM. Most notably, PB reached an AUROC of up to 0.81; with kinetic analysis, it was comparable to BM in performance. MRD is a powerful predictor over the entire natural history of MCL and is suitable for models with a continuous adaptation of patient risk. The study can be found in EudraCT N. 2009-012807-25 (https://eudract.ema.europa.eu/).

A Clinical Prognostic Model Based on Machine Learning from the Fondazione Italiana Linfomi (FIL) MCL0208 Phase III Trial

Simple Summary

The interest in using Machine-Learning (ML) techniques in clinical research is growing. We applied ML to build up a novel prognostic model from patients affected with Mantle Cell Lymphoma (MCL) enrolled in a phase III open-labeled, randomized clinical trial from the Fondazione Italiana Linfomi (FIL)—MCL0208. This is the first application of ML in a prospective clinical trial on MCL lymphoma. We applied a novel ML pipeline to a large cohort of patients for which several clinical variables have been collected at baseline, and assessed their prognostic value based on overall survival. We validated it on two independent data series provided by European MCL Network. Due to its flexibility, we believe that ML would be of tremendous help in the development of a novel MCL prognostic score aimed at re-defining risk stratification.

Abstract

Background: Multicenter clinical trials are producing growing amounts of clinical data. Machine Learning (ML) might facilitate the discovery of novel tools for prognostication and disease-stratification. Taking advantage of a systematic collection of multiple variables, we developed a model derived from data collected on 300 patients with mantle cell lymphoma (MCL) from the Fondazione Italiana Linfomi-MCL0208 phase III trial (NCT02354313). Methods: We developed a score with a clustering algorithm applied to clinical variables. The candidate score was correlated to overall survival (OS) and validated in two independent data series from the European MCL Network (NCT00209222, NCT00209209); Results: Three groups of patients were significantly discriminated: Low, Intermediate (Int), and High risk (High). Seven discriminants were identified by a feature reduction approach: albumin, Ki-67, lactate dehydrogenase, lymphocytes, platelets, bone marrow infiltration, and B-symptoms. Accordingly, patients in the Int and High groups had shorter OS rates than those in the Low and Int groups, respectively (Int→Low, HR: 3.1, 95% CI: 1.0–9.6; High→Int, HR: 2.3, 95% CI: 1.5–4.7). Based on the 7 markers, we defined the engineered MCL international prognostic index (eMIPI), which was validated and confirmed in two independent cohorts; Conclusions: We developed and validated a ML-based prognostic model for MCL. Even when currently limited to baseline predictors, our approach has high scalability potential.

Application of the Euro Clonality next-generation sequencing-based marker screening approach to detect immunoglobulin heavy chain rearrangements in mantle cell lymphoma patients: first data from the Fondazione Italiana Linfomi MCL0208 trial

Minimal residual disease (MRD) determined by classic polymerase chain reaction (PCR) methods is a powerful outcome predictor in mantle cell lymphoma (MCL). Nevertheless, some technical pitfalls can reduce the rate of of molecular markers. Therefore, we applied the EuroClonality‐NGS IGH (next‐generation sequencing immunoglobulin heavy chain) method (previously published in acute lymphoblastic leukaemia) to 20 MCL patients enrolled in an Italian phase III trial sponsored by Fondazione Italiana Linfomi. Results from this preliminary investigation show that EuroClonality‐NGS IGH method is feasible in the MCL context, detecting a molecular IGH target in 19/20 investigated cases, allowing MRD monitoring also in those patients lacking a molecular marker for classical screening approaches.

Targeted locus amplification to detect molecular markers in mantle cell and follicular lymphoma

Minimal residual disease (MRD) monitoring by PCR methods is a strong and standardized predictor of clinical outcome in mantle cell lymphoma (MCL) and follicular lymphoma (FL). However, about 20% of MCL and 40% of FL patients lack a reliable molecular marker, being thus not eligible for MRD studies. Recently, targeted locus amplification (TLA), a next‐generation sequencing (NGS) method based on the physical proximity of DNA sequences for target selection, identified novel gene rearrangements in leukemia. The aim of this study was to test TLA in MCL and FL diagnostic samples lacking a classical, PCR‐detectable, t(11; 14) MTC (BCL1/IGH), or t(14; 18) major breakpoint region and minor cluster region (BCL2/IGH) rearrangements. Overall, TLA was performed on 20 MCL bone marrow (BM) or peripheral blood (PB) primary samples and on 20 FL BM, identifying a novel BCL1 or BCL2/IGH breakpoint in 16 MCL and 8 FL patients (80% and 40%, respectively). These new breakpoints (named BCL1‐TLA and BCL2‐TLA) were validated by ASO primers design and compared as MRD markers to classical IGH rearrangements in eight MCL: overall, MRD results by BCL1‐TLA were superimposable (R Pearson = 0.76) to the standardized IGH‐based approach. Moreover, MRD by BCL2‐TLA reached good sensitivity levels also in FL and was predictive of a primary refractory case. In conclusion, this study offers the proof of principle that TLA is a promising and reliable NGS‐based technology for the identification of novel molecular markers, suitable for further MRD analysis in previously not traceable MCL and FL patients.

Immunoglobulin kappa deleting element rearrangements are candidate targets for minimal residual disease evaluation in mantle cell lymphoma

Minimal residual disease (MRD) assessment is of high clinical relevance in patients with mantle cell lymphoma (MCL). In mature B-cell malignancies, the presence of somatic hypermutations (SHM) in Variable-Diversity-Joining Heavy chain (VDJH) rearrangements leads to frequent mismatches between primers, probes, and the target, thus impairing tumor cells quantification. Alternative targets, such as immunoglobulin kappa-deleting-element (IGK-Kde) rearrangements, might be suitable for MRD detection. We aimed at evaluating the applicability of IGK-Kde rearrangements for MRD quantification in MCL patients by real-time quantitative polymerase chain reaction (RQ-PCR)/digital-droplet-PCR (ddPCR). IGK screening was performed on bone marrow samples from two cohorts: the first from Turin (22 patients enrolled in the FIL-MCL0208 trial, NCT02354313) and the second from Rome (15 patients). IGK-Kde rearrangements were found in 76% (28/37) of cases, representing the sole molecular marker in 73% (8/11) of IGH-BCL1/IGH negative cases. MRD RQ-PCR monitoring was possible in 57% (16/28) of cases, showing a 100% concordance with the conventional targets. However, the frequent background amplification affected the sensitivity of the assay, that was lower in MCL compared to acute lymphoblastic leukemia and in line with multiple myeloma published results. ddPCR had a good concordance with RQ-PCR and it might help to identify false positive/negative results. From a clinical perspective, we suggest that IGK-Kde can be a candidate target for MRD monitoring and deserves a validation of its predictive value in prospective MCL series.

Mantle cell lymphoma

MCL is a well-characterized generally aggressive lymphoma with a poor prognosis. However, patients with a more indolent disease have been reported in whom the initiation of therapy can be delayed without any consequence for the survival. In 2017 the World Health Organization updated the classification of MCL describing two main subtypes with specific molecular characteristics and clinical features, classical and indolent leukaemic nonnodal MCL. Recent research results suggested an improving outcome of this neoplasm. The addition of rituximab to conventional chemotherapy has increased overall response rates, but it did not improve overall survival compared to chemotherapy alone. The use of intensive frontline therapies including rituximab and consolidation with autologous stem cell transplantation ameliorated response rate and prolonged progression-free survival in young fit patients, but any impact on survival remains to be proven. Furthermore, the optimal timing, cytoreductive regimen and conditioning regimen, and the clinical implications of achieving a disease remission even at molecular level remain to be elucidated. The development of targeted therapies as the consequence of better understanding of pathogenetic pathways in MCL might improve the outcome of conventional chemotherapy and spare the toxicity of intense therapy in most patients. Cases not eligible for intensive regimens, may be considered for less demanding therapies, such as the combination of rituximab either with CHOP or with purine analogues, or bendamustine. Allogeneic SCT can be an effective option for relapsed disease in patients who are fit enough and have a compatible donor. Maintenance rituximab may be considered after response to immunochemotherapy as the first-line strategy in a wide range of patients. Finally, since the optimal approach to the management of MCL is still evolving, it is critical that these patients are enrolled in clinical trials to identify the better treatment options.

Applying Data Warehousing to a Phase III Clinical Trial From the Fondazione Italiana Linfomi Ensures Superior Data Quality and Improved Assessment of Clinical Outcomes

PURPOSE

Data collection in clinical trials is becoming complex, with a huge number of variables that need to be recorded, verified, and analyzed to effectively measure clinical outcomes. In this study, we used data warehouse (DW) concepts to achieve this goal. A DW was developed to accommodate data from a large clinical trial, including all the characteristics collected. We present the results related to baseline variables with the following objectives: developing a data quality (DQ) control strategy and improving outcome analysis according to the clinical trial primary end points.

METHODS

Data were retrieved from the electronic case reporting forms (eCRFs) of the phase III, multicenter MCL0208 trial (ClinicalTrials.gov identifier: NCT02354313) of the Fondazione Italiana Linfomi for younger patients with untreated mantle cell lymphoma (MCL). The DW was created with a relational database management system. Recommended DQ dimensions were observed to monitor the activity of each site to handle DQ management during patient follow-up. The DQ management was applied to clinically relevant parameters that predicted progression-free survival to assess its impact.

RESULTS

The DW encompassed 16 tables, which included 226 variables for 300 patients and 199,500 items of data. The tool allowed cross-comparison analysis and detected some incongruities in eCRFs, prompting queries to clinical centers. This had an impact on clinical end points, as the DQ control strategy was able to improve the prognostic stratification according to single parameters, such as tumor infiltration by flow cytometry, and even using established prognosticators, such as the MCL International Prognostic Index.

CONCLUSION

The DW is a powerful tool to organize results from large phase III clinical trials and to effectively improve DQ through the application of effective engineered tools.

Clofarabine and Treosulfan as Conditioning for Matched Related and Unrelated Hematopoietic Stem Cell Transplantation: Results from the Clo3o Phase II Trial

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) can be curative for patients with hematologic malignancies. The ideal conditioning regimen before allo-HSCT has not been established. We conducted a Phase II study to evaluate the tolerability and efficacy of clofarabine and treosulfan as conditioning regimen before allo-HSCT. The primary objective was to evaluate the cumulative incidence of nonrelapse mortality (NRM) on day +100. Forty-four patients (36 with acute myelogenous leukemia, 5 with acute lymphoblastic leukemia, 3 with myelodysplastic syndromes) were enrolled. The median patient age was 47 years, and the median duration of follow-up was 27 months. The conditioning regimen was based on clofarabine 40 mg/m² (days -6 to -2) and treosulfan 14 g/m² (days -6 to -4). Allogeneic hematopoietic stem cells were derived from a sibling (n = 22) or a well-matched unrelated donor (n = 22). Graft-versus-host disease (GVHD) prophylaxis consisted of antithymocyte globulin, rituximab, cyclosporine, and a short-course of methotrexate. The regimen allowed for rapid engraftment and a 100-day NRM of 18%, due mainly to bacterial infections. The incidences of grade II-IV acute GVHD and chronic GVHD were 16% and 19%, respectively. The rates of overall survival (OS), progression-free survival, and relapse at 2 years were 51%, 31%, and 50%, respectively. Significantly different outcomes were observed between patients with low-intermediate and patients with high-very high Disease Risk Index (DRI) scores (1-year OS, 78% and 24%, respectively). Our findings show that the use of treosulfan and clofarabine as a conditioning regimen for allo-HSCT is feasible, with a 78% 1-year OS in patients with a low-intermediate DRI score. However, 1-year NRM was 18%, and despite the intensified conditioning regimen, relapse incidence remains a major issue in patients with poor prognostic risk factors.

KMT2D mutations and TP53 disruptions are poor prognostic biomarkers in mantle cell lymphoma receiving high-dose therapy: a FIL study

In recent years, the outcome of mantle cell lymphoma (MCL) has improved, especially in younger patients, receiving cytarabine-containing chemoimmunotherapy and autologous stem cell transplantation. Nevertheless, a proportion of MCL patients still experience early failure. To identify biomarkers anticipating failure of intensive chemotherapy in MCL, we performed target resequencing and DNA profiling of purified tumor samples collected from patients enrolled in the prospective FIL-MCL0208 phase 3 trial (high-dose chemoimmunotherapy followed by autologous transplantation and randomized lenalidomide maintenance). Mutations of KMT2D and disruption of TP53 by deletion or mutation associated with an increased risk of progression and death, both in univariate and multivariate analysis. By adding KMT2D mutations and TP53 disruption to the MIPI-c backbone, we derived a new prognostic index, the “MIPI-genetic” (“MIPI- g”). The “MIPI-g” improved the model discrimination ability compared to the MIPI-c alone, defining three risk groups: i) low-risk patients (4-year progression free survival and overall survival of 72.0% and 94.5%); ii) inter-mediate-risk patients (4-year progression free survival and overall survival of 42.2% and 65.8%) and iii) high-risk patients (4-year progression free survival and overall survival of 11.5% and 44.9%). Our results: i) confirm that TP53 disruption identifies a high-risk population characterized by poor sensitivity to conventional or intensified chemotherapy; ii) provide the pivotal evidence that patients harboring KMT2D mutations share the same poor outcome as patients harboring TP53 disruption; and iii) allow to develop a tool for the identification of high-risk MCL patients for whom novel therapeutic strategies need to be investigated. (Trial registered at clinicaltrials.gov identifier: NCT02354313).

Abnormal Aggregation and Increased Size of Platelets in Myeloproliferative Disorders

Platelet aggregation is frequently impaired in myeloproliferative disorders (MPD). The presence of spontaneous platelet aggregation (SPA) or alterations of the aggregation pattern after ADP, epinephrine and collagen have been a frequent feature in the series of 52 patients here presented. The occurrence of SPA was not related to the findings obtained with the aggregating agents or to the number of circulating platelets. The aggregation results did not correlate with the number of megathrombocytes.

The presence of platelet abnormalities, not completely corrected after busulfan therapy, and the increased size of platelets should aid in diagnosis of myeloproliferative disorders.

Effect of Aspirin on Platelet 5-Hydroxytryptamine and Beta-Thromboglobulin Plasma Levels in Patients with Myeloproliferative Diseases

14 patients with myeloproliferative diseases (MD) showed low 5-hydroxytryptamine (5-HT) platelet content and high beta-thromboglobulin (β-TG) plasma levels.

This pattern could support the view that MD platelets undergo “in vivo“ degranulation.

A single dose of aspirin was unable to induce modification of platelet 5-HT and plasma β-TG, whereas 6 out of 14 patients

No modification of platelet 5-HT was obtained suggesting that the cause of dense bodies deficiency may lie in the production of abnormal platelets and not be related to “in vivo” degranulation.

Increased Thromboxane Biosynthesis in Essential Thrombocythemia

In order to investigate the in vivo thromboxane (TX) biosynthesis in essential thromboeythemia (ET), we measured the urinary exeretion of the major enzymatic metabolites of TXB2, 11-dehydro-TXB2 and 2,3-dinor-TXB2 in 40 ET patients as well as in 26 gender- and age-matched controls. Urinary 11-dehydro-TXB2 was significantly higher (p <0.001) in thrombocythemic patients (4,063 ± 3,408 pg/mg creatinine; mean ± SD) than in controls (504 ± 267 pg/mg creatinine), with 34 patients (85%) having 11-dehydro-TXB2 >2 SD above the control mean. Patients with platelet number <1,000 × 109/1 (n = 25) had significantly higher (p <0.05) 11 -dehydro-TXB2 excretion than patients with higher platelet count (4,765 ± 3,870 pg/mg creatinine, n = 25, versus 2,279 ± 1,874 pg/mg creatinine, n = 15). Average excretion values of patients aging >55 was significantly higher than in the younger group (4,784 ± 3,948 pg/mg creatinine, n = 24, versus 2,405 ± 1,885 pg/mg creatinine, n = 16, p <0.05). Low-dose aspirin (50 mg/d for 7 days) largely suppressed 11-dehydro-TXB2 excretion in 7 thrombocythemic patients, thus suggesting that platelets were the main source of enhanced TXA2 biosynthesis. The platelet count-corrected 11-dehydro-TXB2 excretion was positively correlated with age (r = 0.325, n = 40, p <0.05) and inversely correlated with platelet count (r = -0.381, n = 40, p <0.05). In addition 11 out of 13 (85%) patients having increased count-corrected 11-dehydro-TXB2 excretion, belonged to the subgroup with age >55 and platelet count <1,000 × 1099/1. We conclude that in essential thrombocythemia: 1) enhanced 11-dehydro-TXB2 excretion largely reflects platelet activation in vivo;2) age as well as platelet count appear to influence the determinants of platelet activation in this setting, and can help in assessing the thrombotic risk and therapeutic strategy in individual patients.

Recombinant Versus High-sensitivity Conventional Thromboplastin: A Randomized Clinical Study in Patients on Oral Anticoagulation

A prospective, randomized, double-blind clinical trial was carried out in a single center to compare the clinical and laboratory quality of oral anticoagulant therapy monitored with recombinant tissue factor (RTF) or with a sensitive, human-derived, conventional thromboplastin (CT) in the PT test. Seven hundred and fifty-seven consecutive patients receiving oral anticoagulation for various indications were randomized to RTF (n = 379) or CT (n = 368) for 6 months. Total follow-up was 167 and 153 patient-years for RTF and TP groups respectively. Fifty-six bleeding events were observed: 31 in the RTF group and 25 in the TP group. The incidence of bleeding was 18.5 and 16.5% pt-yrs for RTF and TP patients respectively (n.s.). The event-free follow-up curves were not significantly different between the two groups. The laboratory quality of oral anticoagulation was evaluated with the “last check in file” method: therapeutic INR was found in the same propor-tipn of RTF and TP patients (70.2% vs 68.8%). Our study shows that RTF is as effective as a sensitive, conventional thromboplastin for monitoring oral anticoagulation.

Platelet Activation in Myeloproliferative Disorders

Beta-thromboglobulin (beta-TG) and platelet factor four (PF4) are specific platelet proteins released when a process of platelet activation occurs.

The present study was undertaken in order to measure beta-TG and PF4 both as absolute plasma value and ratio to platelet number in 69 patients with myeloproliferative disorders (MD). The aim was to establish whether the increase of the two proteins could depend on platelet number or indicated an “in vivo” platelet activation.

In 74% of patients beta-TG was found elevated and PF4 was high in 68% of cases. However in 34.7% and in 31.9% of cases respectively, the elevation of the two platelet markers was correlated to platelet number and the ratio was normal. Only in about one third of cases an “in vivo” platelet activation could be admitted and this finding provides a more rational use of antiaggregating agents.

Thrombotic and Hemorrhagic Complications in Patients with Mechanical Heart Valve Prosthesis Attending an Anticoagulation Clinic

This study evaluated the advantage of an anticoagulation clinic in terms of the improvement of the clinical quality of oral anticoagulation (i.e. prevention of thromboembolism and low rate of hemorrhagic complications). The incidence of thromboembolic events and major hemorrhagic complications was assessed in a series of 271 patients on oral anticoagulation for mechanical heart valve prosthesis before and after their enrollment in our anticoagulation clinic from January 1987 to December 1990. Risk factors for hemostatic events were also analyzed. The incidence of major hemostatic complications was significantly lower when patients attended the clinic: 1.0 vs 4.9%/pt-yr for hemorrhage and 0.6 vs 6.6%/pt-yr for thrombosis. This depended on three main factors: better dose regulation of warfarin, continuous patient education and early identification of clinical conditions potentially at risk for thrombosis and hemorrhage. Only previous hemorrhagic or thromboembolic events were recognized as major risk factors for hemostatic complications.

In conclusion, our study shows that an anticoagulation clinic offers a real advantage to patients with mechanical heart valve prosthesis in terms of prevention of thromboembolic events and hemorrhagic complications.

Prolonged Bleeding Time in Patients with Lupus Anticoagulant

Platelet adhesion to collagen under flow conditions was studied in 18 patients with lupus anticoagulant, seven of which showed a prolonged bleeding time in the presence of a normal platelet count. The effect of patient plasma, IgG and purified anticardiolipin antibodies on platelet adhesion was also examined. We found a significant reduction of platelet adhesion in patients with lupus anticoagulant, which was more evident in patients with prolonged bleeding time. This platelet adhesion defect could be attributed to a plasma factor. In fact, patients' platelets regained normal adhesion when mixed with normal plasma, whereas controls' platelets showed abnormal adhesion in the presence of patient plasma. A causative role of antiphospholipid antibodies was demonstrated in experiments using purified immunoglobulins and anticardiolipin antibodies.

Increased Response to Arachidonic Acid and U-46619 and Resistance to Inhibitory Prostaglandins in Patients with Chronic Myeloproliferative Disorders

In patients with myeloproliferative disorders (MPD) a group of related diseases of the bone marrow stem cell and recurrent haemorrhagic and/or thrombotic complications, the production of aggregating prostaglandins (PGs) may be normal or slightly reduced, while PGI2 production is normal. However, MPD platelet sensitivity to antiaggregatory PGs is still unknown.

We studied the potency of PGD2, PGI2 and PGEi as inhibitors of platelet aggregation induced by threshold aggregating concentrations of arachidonic acid and U-46619-analogue of the cyclic endoperoxide PGH2 in 20 patients with MPD in comparison with healthy controls, with the aim of evaluating the sensitivity of MPD platelets to antiaggregatory PGs. In these patients platelet prostanoid metabolism was normal. However, the functional response of platelets to aggregating and antiaggregating prostanoids was shifted towards potentially increased platelet aggregation response. These findings could have a clinical relevance in view of the haemostatic and thrombotic complications so frequent in MPD.

A B-cell receptor-related gene signature predicts survival in mantle cell lymphoma: results from the Fondazione Italiana Linfomi MCL-0208 trial

Mantle cell lymphoma patients have variable clinical courses, ranging from indolent cases that do not require immediate treatment to aggressive, rapidly progressing diseases. Thus, diagnostic tools capable of stratifying patients according to their risk of relapse and death are needed. This study included 83 samples from the Fondazione Italiana Linfomi MCL-0208 clinical trial. Through gene expression profiling and quantitative real-time PCR we analyzed 46 peripheral blood and 43 formalin-fixed paraffin-embedded lymph node samples. A prediction model to classify patients was developed. By analyzing the transcriptome of 27 peripheral blood samples, two subgroups characterized by a differential expression of genes from the B-cell receptor pathway (B-cell receptor^low and B-cell receptor^high) were identified. The prediction model based on the quantitative real-time PCR values of six representative genes (AKT3, BCL2, BTK, CD79B, PIK3CD, and SYK), was used to classify the 83 cases (43 B-cell receptor^low and 40 B-cell receptor^high). The B-cell receptor^high signature associated with shorter progression-free survival (P=0.0074), selected the mantle cell lymphoma subgroup with the shortest progression-free survival and overall survival (P=0.0014 and P=0.029, respectively) in combination with high (>30%) Ki-67 staining, and was an independent predictor of short progression- free survival along with the Mantle Cell Lymphoma International Prognostic Index-combined score. Moreover, the clinical impact of the 6- gene signature related to the B-cell receptor pathway identified a mantle cell lymphoma subset with shorter progression-free survival intervals also in an external independent mantle cell lymphoma cohort homogenously treated with different schedules. In conclusion, this 6-gene signature associates with a poor clinical response in the context of the MCL- 0208 clinical trial. (clinicaltrials.gov identifier: 02354313).

Khorana score and histotype predicts incidence of early venous thromboembolism in non-Hodgkin lymphomas. A pooled-data analysis of 12 clinical trials of Fondazione Italiana Linfomi (FIL)

Current data suggests that the risk of venous thromboembolism (VTE) in patients with non-Hodgkin lymphoma (NHL) is comparable to that observed in patients with solid tumours, although more robust confirmatory analyses are required. With that in mind, we investigated the occurrence of VTE in a pooled analysis of 12 "Fondazione Italiana Linfomi" (FIL) prospective clinical studies. Specifically, we wished to assess the cumulative incidence of VTE in NHL patients, evaluate the predictive value of the Khorana Score (KS), and identify other potential risk factors for VTEs. Data for VTE occurrence were retrieved from study databases and pharmacovigilance reports. Our analysis includes 1717 patients from 12 prospective phase II and III trials, including newly diagnosed NHL. We observed 53 VTEs (any grade) in 46 patients, with 20 severe VTEs in 17 patients. The cumulative incidences for "all-grade" or grade ≥3 VTEs were 2.9 % (95 % CI: 2.1-3.8) and 1.1 % (95 % CI: 0.6-1.6), respectively. KS categories were positively associated with the risk of VTE of any grade, and with severe events (i. e. grade ≥3; Gray's test p-values = 0.048 and 0.012, respectively). Among NHL patients, those with diffuse large B-cell lymphoma (DLBCL) showed a greater risk of (any grade) VTE (HR: 3.42, 95 % CI: 1.32-8.84, p-value = 0.011). Our study indicates that 1) VTE is a relevant complication for NHL patients, 2) KS is predictive of VTE events and 3) DLBCL histotype is an independent risk factor for VTE incidence, for which preventative interventions could be considered.

Randomized Trial Comparing R-CHOP Versus High-Dose Sequential Chemotherapy in High-Risk Patients With Diffuse Large B-Cell Lymphomas

Purpose The benefit of high-dose chemotherapy with autologous stem-cell transplantation (ASCT) as first-line treatment in patients with diffuse large B-cell lymphomas is still a matter of debate. To address this point, we designed a randomized phase III trial to compare rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP)-14 (eight cycles) with rituximab plus high-dose sequential chemotherapy (R-HDS) with ASCT. Patients and Methods From June 2005 to June 2011, 246 high-risk patients with a high-intermediate (56%) or high (44%) International Prognostic Index score were randomly assigned to the R-CHOP or R-HDS arm, and 235 were analyzed by intent to treat. The primary efficacy end point of the study was 3-year event-free survival, and results were analyzed on an intent-to-treat basis. Results Clinical response (complete response, 78% v 76%; partial response, 5% v 9%) and failures (no response, 15% v 11%; and early treatment-related mortality, 2% v 3%) were similar after R-CHOP versus R-HDS, respectively. After a median follow-up of 5 years, the 3-year event-free survival was 62% versus 65% ( P = .83). At 3 years, compared with the R-CHOP arm, the R-HDS arm had better disease-free survival (79% v 91%, respectively; P = .034), but this subsequently vanished because of late-occurring treatment-related deaths. No difference was detected in terms of progression-free survival (65% v 75%, respectively; P = .12), or overall survival (74% v 77%, respectively; P = .64). Significantly higher hematologic toxicity ( P < .001) and more infectious complications ( P < .001) were observed in the R-HDS arm. Conclusion In this study, front-line intensive R-HDS chemotherapy with ASCT did not improve the outcome of high-risk patients with diffuse large B-cell lymphomas.

PO-03 - Khorana score and histotype predict the incidence of early venous thromboembolism (VTE) in Non Hodgkin Lymphoma (NHL). A pooled data analysis of twelve clinical trials of Fondazione Italiana Linfomi (FIL)

BACKGROUND

Recent studies show that the risk of VTE in NHL pts is similar to that observed in high risk solid tumors (i.e. pancreatic, ovarian cancer). VTE in NHL occurs in most cases within three months from diagnosis and can have substantial impact on treatment delivery and outcome as well as on quality of life. However few data are available on potential predictors.

AIMS

To better clarify the epidemiology of early (within six months from treatment start) VTE in NHL we conducted a pooled data analysis of 12 clinical trials from FIL. Our analysis included basic demographic features, lymphoma-related characteristics as well the Khorana score (based on histology, BMI, platelets WBC and HB counts) which is extensively used in solid tumors to predict VTE risk.

PATIENTS AND METHODS

From Jan. 2010 to Dec. 2014, all pts with B-cell NHL enrolled in prospective clinical trials from FIL for frontline treatment were included. For 9 studies study period included the entire trial population was included. The analyses were conducted based on CRFs as well as pharmacovigilance reports. VTE definition and grading was stated according to standard criteria of toxicity (CTCAE V4.0). Cumulative incidence of VTE from the study enrollment was estimated using the method described by Gooley et al. accounting for death from any causes as a competing risk. The Fine & Gray survival model was used to identify predictors of VTE among NHL pts. Factors predicting the grade of VTE were investigated using an ordinal logistic regression model. This pooled data analysis was approved by local IRB.

RESULTS

Overall, 1,717 patients belonging to 12 studies were evaluated. Eight were phase I/II or II (25% of pts) and 4 phase III (75% of pts). M/F ratio was 1.41, Median age was 57, (IQ range (IQR) 49-66). Histologies were: DLCL-B 34%, FL 41%, MCL 18%, other 6%. Median BMI was 25 (IQR 22-28). Median Hb, WBC and platelets counts were 13g/dl) (IQR 11.5-14.2), 7.1*10^(9)/l (IQR 5.6-10.3), 224*10^(9)/l (IQR 169-298), respectively. 1189 pts were evaluable Khorana score: 58% low risk, 30% intermediate risk, 12% were high risk. Human erythropoetin support was given to 9% of patients. All pts received Rituximab. Planned therapeutic programs included ASCT in 27% of pts, conventional chemotherapy in 67% a conventional chemotherapy plus lenalidomide in 6%. Overall 59 any grade VTE episodes occurred in 51 pts (2.9%), including 21 grade III-IV VTE (18 pts). None was fatal. Median time from study enrolment to VTE was 63 days (IQR: 35-110). Considering death as a competitive event the 6 months cumulative incidence of VTE was 2,2% in low risk Khorana score, 4.5% (95%IC: 2.3-6.7) in intermediate and 6.6% (95%IC: 2.4-10.8) in high risk (p=0.012) (figure 1). Khorana score was predictive also for grade III-IV events as they were 0,7% (95% CI:0.1-1.4) in low risk and 2.0% (95% CI:0.8-3.3) in intermediate-high risk (p=0.048). The results were similar also after excluding lenalidomide containing studies. The Fine and Gray multivariate analyses, adjusted for age and stage, showed that Khorana score (intermediate risk adjHR=1.96; 95%IC: 0.84-4.56 and high risk adjHR=3.81; 95%IC: 1.51-9.58) and DLCL-B histotype (adjHR=2.58; 95% CI: 1.01-6.55) were independently associated to an increased risk of VTE. Moreover an ordinal logistical regression model indicated that the increase of one point in the Khorana score resulted in an increased risk of VTE (OR=1.85; 95% CI: 1.23-2.79).

CONCLUSIONS

Our results suggest that DLCL-B histotype and Khorana score are predictors of VTE in NHL. The latter might become a simple and effective tool to assess the risk of VTE in NHL. Prospective validation including also patients not eligible for clinical trials is needed.

Bortezomib, Thalidomide and Lenalidomide: Have They Really Changed the Outcome of Multiple Myeloma?

Treatment of multiple myeloma (MM) has significantly improved, although the disease remains incurable. Prospective clinical trials evaluating the impact on outcome of new drugs such as proteasome inhibitors or immunomodulating agents are limited since they are not able to reflect the clinical routine and available retrospective data are not detailed enough to directly evaluate the value of new drugs. To address these information gaps, we performed a retrospective real-life analysis. We retrospectively assessed 949 patients treated for multiple myeloma or plasma cell leukemia at three Italian cancer centers in the years 1979-2014. Clinical features at the time of diagnosis were consistent with what was observed in clinical routine. A total of 39% of patients underwent high-dose chemotherapy followed by autologous stem cell transplantation (ASCT). The median overall survival (OS) of the whole group was 5.4 years and ranged from 3.4 years for patients who did not receive at least one of the new drugs compared to 5.9 years in the other patients (p<0.001). The improvement in OS due to administration of new drugs was also observed among different prognostic sub-groups such as age, Durie and Salmon stage, international staging system and renal impairment. Availability of new drugs significantly improved survival of patients who underwent ASCT and also those who did not. In conclusion, we provided evidence that the advent of the new drugs drastically improved the outcome of patients with MM, also in cases with poor risk at the time of diagnosis. ASCT is still of major importance in the treatment of this disease. Nevertheless, MM remains incurable and new therapeutic approaches are warranted.

Extranodal Marginal Zone Lymphoma of Mucosa-Associated Lymphoid Tissue of the Salivary Glands: A Multicenter, International Experience of 248 Patients (IELSG 41)

BACKGROUND

The salivary gland is one of the most common sites involved by nongastric, extranodal marginal zone lymphomas of mucosa-associated lymphoid tissue (MALT). A large series of patients with long-term follow-up has not been documented. This multicenter, international study sought to characterize the clinical characteristics, treatment, and natural history of salivary gland MALT lymphoma.

METHODS

Patients with biopsy-confirmed salivary gland MALT lymphoma were identified from multiple international sites. Risk factors, treatment, and long-term outcomes were evaluated.

RESULTS

A total of 247 patients were evaluated; 76% presented with limited-stage disease. There was a history of autoimmune disorder in 41%, with Sjögren disease being the most common (83%). Fifty-seven percent of patients were initially treated with local therapy with surgery, radiation, or both; 37 of patients were treated with systemic therapy initially, with 47% of those receiving rituximab; and 6% of patients were observed. The median overall survival (OS) was 18.3 years. The median progression-free survival (PFS) following primary therapy was 9.3 years. There was no difference in the outcomes between patients receiving local or systemic therapy in first-line management. On multivariate analysis, age <60 years and low to intermediate international prognostic index were associated with improved OS and PFS; Sjögren disease was associated with improved OS.

CONCLUSION

Salivary gland MALT lymphoma has an excellent prognosis regardless of initial treatment, and patients with Sjögren disease have improved survival. Risks for long-term complications must be weighed when determining initial therapy.

Role of blood cells dynamism on hemostatic complications in low-risk patients with essential thrombocythemia

Patients with essential thrombocythemia (ET) aged less than 60 years, who have not suffered a previous vascular event (low-risk patients), may develop thrombotic or hemorrhagic events. So far, it has not been possible to identify useful markers capable of predicting which of these patients are more likely to develop an event and therefore who needs to be treated. In the present study, we analysed the relationship between vascular complications and longitudinal blood counts of 136 low-risk ET patients taken over a sustained period of time (blood cells dynamism). After a median follow-up of 60 months, 45 out of 136 patients (33%) suffered 40 major thrombotic and 5 severe hemorrhagic complications. A total number of 5,781 blood counts were collected longitudinally. Thrombotic and hemorrhagic events were studied together (primary endpoint) but also separately (thrombotic alone = secondary endpoint; hemorrhagic alone = tertiary endpoint). The primary endpoint showed no significant association between platelet and WBC count at diagnosis and risk of any event (platelet, p = 0.797; WBC, p = 0.178), while Hb at baseline did show an association (p = 0.024). In the dynamic analysis with Cox regression model, where the blood count values were studied by time of follow-up, we observed that the risk for Hb was 1.49 (95% CI 1.13-1.97) for every increase of 1 g/dL, and that this risk then marginally decreased during follow-up. WBC was associated with an increased risk at baseline for every increase of 1 × 10(9)/L (hazard ratio (HR) 1.07, 95% CI 1.01-1.13, p = 0.034), the risk was stable during follow-up (HR 0.95, p = 0.187 at 60 months). Also, for each increment at baseline of 100 × 10(9) platelets/L, HR was increased by 1.08 (95% CI 0.97-1.22, p = 0.159) and decreases during follow-up. In conclusion, this study is the first to evaluate in ET low-risk patients, the risk of developing a thrombotic/hemorrhagic event considering blood counts over time. Overall our study shows that the risk changes over time. For example, the risk associated with WCC is not linear as previously reported. An interesting new finding is that PLT and even Hb contribute to the risk of developing vascular events. Future treatments should take into consideration these findings and aim to control all parameters over time. We believe this early study may help develop a dynamic analysis model to predict thrombosis in the single patient. Further studies are now warranted to further validate our findings.

Anagrelide treatment and cardiovascular monitoring in essential thrombocythemia. A prospective observational study

In this prospective observational single-center study, 55 patients with essential thrombocythemia who were candidates for second line treatment with anagrelide (ANA) received a preliminary cardiovascular (CV) clinical, instrumental and biochemical evaluation (CV history and symptoms, CV risk factors, blood pressure, heart rate, ECG and ECHO-cardio parameters, Troponin I, NT-proBNP). After this in-depth CV screening, 54 out of 55 patients were deemed to be fit for ANA treatment. Thirty-eight of the 55 patients received ANA treatment for a median of 36 months (range 3-48), and were monitored using the same CV evaluation. Fourteen of these 38 patients manifested CV adverse events (10 palpitation, 4 edema, 2 arterial hypertension, 2 acute myocardial infarction) that were not predicted by the in-depth CV evaluation, and that led to ANA withdrawal in only one case (non-cardiac refractory edema). In conclusion, the planned in-depth CV evaluation did not appear to be necessary in ET patients to evaluate their suitability for ANA treatment, and, moreover, was not able to predict the occurrence of CV adverse events during ANA treatment. Nevertheless, the CV adverse events (mostly palpitations and edema) were easily managed by the hematologists, and required the cardiologist involvement in very few selected cases.

Randomized trial of radiation-free central nervous system prophylaxis comparing intrathecal triple therapy with liposomal cytarabine in acute lymphoblastic leukemia

Developing optimal radiation-free central nervous system prophylaxis is a desirable goal in acute lymphoblastic leukemia, to avoid the long-term toxicity associated with cranial irradiation. In a randomized, phase II trial enrolling 145 adult patients, we compared intrathecal liposomal cytarabine (50 mg: 6/8 injections in B-/T-cell subsets, respectively) with intrathecal triple therapy (methotrexate/cytarabine/prednisone: 12 injections). Systemic therapy included methotrexate plus cytarabine or L-asparaginase courses, with methotrexate augmented to 2.5 and 5 g/m(2) in Philadelphia-negative B- and T-cell disease, respectively. The primary study objective was the comparative assessment of the risk/benefit ratio, combining the analysis of feasibility, toxicity and efficacy. In the liposomal cytarabine arm 17/71 patients (24%) developed grade 3-4 neurotoxicity compared to 2/74 (3%) in the triple therapy arm (P=0.0002), the median number of episodes of neurotoxicity of any grade was one per patient compared to zero, respectively (P=0.0001), and even though no permanent disabilities or deaths were registered, four patients (6%) discontinued intrathecal prophylaxis on account of these toxic side effects (P=0.06). Neurotoxicity worsened with liposomal cytarabine every 14 days (T-cell disease), and was improved by the adjunct of intrathecal dexamethasone. Two patients in the liposomal cytarabine arm suffered from a meningeal relapse (none with T-cell disease, only one after high-dose chemotherapy) compared to four in the triple therapy arm (1 with T-cell disease). While intrathecal liposomal cytarabine could contribute to improved, radiation-free central nervous system prophylaxis, the toxicity reported in this trial does not support its use at 50 mg and prompts the investigation of a lower dosage. (clinicaltrials.gov identifier: NCT-00795756).

A diachronic-comparative analysis for the identification of the most powerful prognostic index for localized diffuse large B-cell lymphoma

BACKGROUND

In the rituximab era, the conventional International Prognostic index (IPI) lost at least in part its predictive power, while the National Comprehensive Cancer Network-IPI (NCCN-IPI) seems to be a new and valid prognosticator. However, it has not yet been evaluated in patients with localized disease and it has not been compared with the modified IPI (mIPI) of the pre-rituximab era. In order to evaluate the different prognosticators and to assess the importance of rituximab and radiotherapy (RT), we carried out the so far largest retrospective analysis of patients with localized diffuse large B-cell lymphoma (DLBCL).

PATIENTS AND METHODS

We retrospectively assessed clinical and therapeutical data of 1405 patients treated in from 1987 to 2012 in 10 cancer centers in Italy and 1 in Austria.

RESULTS

All patients underwent an anthracycline containing polychemotherapy and 254 additional rituximab. The median follow-up was 5.7 years (range 0.1-23 years). The 5-year overall survival (OS) was 75%, being significantly superior in those who underwent additional rituximab, while RT consolidation did not improve the outcome of those who received immunochemotherapy. Patients with extranodal disease benefited from the addition of rituximab, while RT did not improve OS of the immunochemotherapy subgroup. In the pre-rituximab era, the mIPI showed a better performance than the others. In rituximab-treated patients, the NCCN-IPI had the highest discriminant value and the 5-years OS varied significantly (P < 0.001) between the three risk groups and was 98% in low-risk patients, 82% in those with a low-intermediate risk and 57% among high-intermediate and high-risk cases.

CONCLUSIONS

The NCCN-IPI is so far the best prognosticator for patients with localized DLBCL who underwent R-CHOP(-like). The addition of rituximab is indispensable regardless of the risk category and site of involvement, while the addition of RT should be reserved to those cases who are ineligible to rituximab.

Treatment of graft versus host disease with mesenchymal stromal cells: a phase I study on 40 adult and pediatric patients

This phase I multicenter study was aimed at assessing the feasibility and safety of intravenous administration of third party bone marrow-derived mesenchymal stromal cells (MSC) expanded in platelet lysate in 40 patients (15 children and 25 adults), experiencing steroid-resistant grade II to IV graft-versus-host disease (GVHD). Patients received a median of 3 MSC infusions after having failed conventional immunosuppressive therapy. A median cell dose of 1.5 × 10(6)/kg per infusion was administered. No acute toxicity was reported. Overall, 86 adverse events and serious adverse events were reported in the study, most of which (72.1%) were of infectious nature. Overall response rate, measured at 28 days after the last MSC injection, was 67.5%, with 27.5% complete response. The latter was significantly more frequent in patients exhibiting grade II GVHD as compared with higher grades (61.5% versus 11.1%, P = .002) and was borderline significant in children as compared with adults (46.7 versus 16.0%, P = .065). Overall survival at 1 and 2 years from the first MSC administration was 50.0% and 38.6%, with a median survival time of 1.1 years. In conclusion, MSC can be safely administered on top of conventional immunosuppression for steroid resistant GVHD treatment. Eudract Number 2008-007869-23, NCT01764100.

Bendamustine in chronic lymphocytic leukemia: outcome according to different clinical and biological prognostic factors in the everyday clinical practice

Bendamustine proved to be effective for the treatment of chronic lymphocytic leukemia (CLL). However, the relationship between its activity with clinico-biological prognosticators has been addressed only in few studies. We retrospectively evaluated the efficacy of bendamustine, in a real-life contest, on 142 patients, median age 70 years, median number of previous regimens 2 (0-8, 13% previously untreated). Bendamustine was administered for a median number of 4 cycles, in 84% of cases with rituximab. Overall (ORR) and complete response (CRR) rates were 68 and 16.5%, respectively. Multivariate analysis demonstrated a relationship between ORR and number of prior treatments (OR 0.25, 95% CI 0.08-0.71; P = 0.009), del(17p) (OR 0.10, 95% CI 0.03-0.32; P < 0.001) and concomitant rituximab (OR 4.37, 95% CI 1.12-17.04; P = 0.033). The estimated 1- and 2-years overall survival (OS) and progression free survival (PFS) rates were 76, 61, 51, and 26%, respectively. Previous sensitivity to fludarabine (HR 0.36, 95% CI 0.16-0.82), response to bendamustine (HR 0.21, 95% CI 0.10-0.45), and del(17p) (HR 2.18, 95% CI 1.002-4.74) had a prognostic significance in multivariate analysis for PFS, while the number of previous therapies (HR 3.48, 95% CI 1.29-9.38; P = 0.014), concomitant use of rituximab (HR 0.32, 95% CI 0.11-0.93) and response to bendamustine (HR 0.22, 95% CI 0.07-0.66) were significant for OS. Side effects included grade 3-4 neutropenia, infections, thrombocytopenia and anemia which occurred in 40, 14, 14, and 10% of patients, respectively. These results confirm the activity and safety of bendamustine and rituximab combination even in patients with unfavorable clinical and biological features excluding del(17p).

Early-stage diffuse large B cell lymphoma of the head and neck: clinico-biological characterization and 18 year follow-up of 488 patients (IELSG 23 study)

It is known that extranodal head and neck diffuse large B cell lymphomas (eHN-DLBCL) can affect various anatomical structures what is not well-known, however, is whether they differ in terms of clinical presentation and outcome. Clinical data of the multi-institutional series, the largest of its kind as yet, has been analysed with the aim of answering these open questions and providing long-term follow-up information. Data from 488 patients affected by stage I/II eHN-DLBCL was collected: 300 of the Waldeyer's Ring (WR), 38 of the parotid and salivary glands (PSG), 48 of the thyroid gland (TG), 53 of the nasal cavity and paranasal sinuses (NPS), 24 of the palate and oral cavity (POC) and 25 with more than one involved site. Different eHN-DLBCL arising have distinct characteristics at presentation. The intermediate high risk-modified IPI was 67 % in TG, 44 % in WR, 38 % in PSG and POC and 20 % in MS. The worst 5-year survival rate had TG-DLBCL (61 %) due to the 61 % of patients with a mIPI >1. The addition of radiotherapy (cRT) to remitters did not translate into a survival advantage (5-year disease-free survival of 67 % in the cRT group vs. 70 % in the other). Three of four central nervous system recurrences occurred in NPS-DLBCL. Survival of HN-DLBCL was inferior to nodal DLBCL. This study showed that eHN-DLBCL remitters have an inferior survival when compared to nodal DLBCL, and that the addition of cRT does not provide a survival advantage. Since the standard of care nowadays is chemo-immunotherapy, survival of these patients might have been improved.

"Idiopathic Bence-Jones proteinuria": a new characterization of an old entity

Idiopathic Bence-Jones proteinuria (BJP) is a rare plasma cell dyscrasia, of which the clinical and biological characteristics are yet unclear. Historical data suggested that they are at higher risk of progression to multiple myeloma or other related neoplasms, while recent findings are contradictory. To address these open questions, we evaluated a series of both BJP and monoclonal gammopathy of undetermined significance (MGUS) with production of an intact immunoglobulin plus Bence-Jones proteinuria (MGUS+BJP) with long-term follow-up, regarding their clinical characteristics and progression to multiple myeloma, amyloidosis or other related B cell lymphoproliferative disorders. Two hundred and twenty-nine persons fulfilling the 2004 criteria of MGUS were included in the final analyses: 31 had BJP and 198 had MGUS+BJP. At the time of diagnosis, significantly more persons in the BJP group had renal impairment, anaemia and polyneuropathy. A more detailed analysis revealed discrepancies between the serum and urine light chain type in nine cases, reflecting clonal heterogeneity. The number of disease progressions was higher in MGUS+BJP (n = 30) when compared to BJP (n = 1), with a rate of 1.6 and 0.4 progressions per 100 person-years, respectively. In conclusion, BJP has distinct clinical characteristics and a lower risk of progression when compared to MGUS+BJP. Our data suggest that MGUS+BJP being closer to malignant transformation may be due to the higher portion of genetically heterogeneous, pre-malignant plasma cell subclones.