B-Myb deficiency boosts bortezomib-induced immunogenic cell death in colorectal cancer.

B-Myb has received considerable attention for its critical tumorigenic function of supporting DNA repair. However, its modulatory effects on chemotherapy and immunotherapy have rarely been reported in colorectal cancer. Bortezomib (BTZ) is a novel compound with chemotherapeutic and immunotherapeutic effects, but it fails to work in colorectal cancer with high B-Myb expression. The present study was designed to investigate whether B-Myb deletion in colorectal cancer could potentiate the immune efficacy of BTZ against colorectal cancer and to clarify the underlying mechanism. Stable B-Myb knockdown was induced in colorectal cancer cells, which increased apoptosis of the cancer cells relative to the control group in vitro and in vivo. We found that BTZ exhibited more favourable efficacy in B-Myb-defective colorectal cancer cells and tumor-bearing mice. BTZ treatment led to differential expression of genes enriched in the p53 signaling pathway promoted more powerful downstream DNA damage, and arrested cell cycle in B-Myb-defective colorectal cancer. In contrast, recovery of B-Myb in B-Myb-defective colorectal cancer cells abated BTZ-related DNA damage, cell cycle arrest, and anticancer efficacy. Moreover, BTZ promoted DNA damage-associated enhancement of immunogenicity, as indicated by potentiated expression of HMGB1 and HSP90 in B-Myb-defective cells, thereby driving M1 polarization of macrophages. Collectively, B-Myb deletion in colorectal cancer facilitates the immunogenic death of cancer cells, thereby further promoting the immune efficacy of BTZ by amplifying DNA damage. The present work provides an effective molecular target for colorectal cancer immunotherapy with BTZ.

Megalosplenia as an initial manifestation of multiple myeloma with a novel CYLD gene mutation: A case report and literature review.

INTRODUCTION: Megalosplenia in newly diagnosed multiple myeloma (MM) is extremely rare, posing diagnostic and therapeutic challenges due to its unusual location and clinical manifestations and lack of optimal therapeutic strategies. CASE PRESENTATION: A 65-year-old female who was previously healthy presented with a history of ecchymosis on her right leg accompanied by progressive fatigue for 2 weeks. She was admitted to our center in July 2019 due to thrombocytopenia. The patient presented with megalosplenia, anemia, monoclonal protein (λ-light chain type) in the serum and urine, and 45.6% malignant plasma cells in the bone marrow. Splenectomy was performed due to persistent splenomegaly after 3 cycles of the bortezomib plus dexamethasone regimen, and immunohistochemistry results indicated λ-plasmacytoma of the spleen. The same cytogenetic and molecular abnormalities, including t(14;16), 14q32 amplification, 16q32 amplification, 20q12 amplification, and a novel CYLD gene mutation, were identified using fluorescence in situ hybridization and next-generation sequencing in both bone marrow and spleen samples. Therefore, a diagnosis of MM (λ-light chain type, DS III, ISS III, R-ISS III, high-risk) with spleen infiltration was proposed. The patient did not achieve remission after induction treatment with bortezomib plus lenalidomide and dexamethasone or salvage therapy with daratumumab plus ixazomib and dexamethasone. However, she ultimately did achieve very good partial remission with a regimen of bendamustine plus lenalidomide and dexamethasone. Unfortunately, she died of pneumonia associated with chemotherapy. CONCLUSION: To our knowledge, only 8 cases of spleen plasmacytoma at MM diagnosis have been described previously. Extramedullary myeloma patients with spleen involvement at diagnosis are younger and that the condition is usually accompanied by splenic rupture with aggressive clinical features and poor prognosis. Further studies are needed to explore pathogenesis and effective therapies to prolong the survival of such patients.

When Waldenström macroglobulinemia hits the kidney: Description of a case series and management of a "rare in rare" scenario.

BACKGROUND: Renal injury related to Waldenström macroglobulinemia (WM) occurs in approximately 3% of patients. Kidney biopsy is crucial to discriminate between distinct histopathological entities such as glomerular (amyloidotic and non-amyloidotic), tubulo-interstitial and non-paraprotein mediated renal damage. In this context, disease characterization, management, relationship between renal, and hematological response have been poorly explored. We collected clinical, genetic and laboratory data of seven cases of biopsy-proven renal involvement by WM managed at our academic center and focused on three cases we judged paradigmatic discussing their histopathological patterns, clinical features, and therapeutic options. CASE: In this illustrative case series, we confirm that serum creatinine levels and 24 h proteinuria are parameters that when altered should prompt the clinical suspicion of WM-related renal involvement, even if at present there are not precise cut-off levels recommending the execution of a renal biopsy. In our series AL Amyloidosis (n = 3/7) and tubulo-interstitial infiltration by lymphoma cells (n = 3/7) were the two more represented entities. BTKi did not seem to improve renal function (Case 1), while bortezomib-based regimens demonstrated a beneficial activity on the hematological and organ response, even when used as second-line therapy after chemoimmunotherapy (Case 3) and also with coexistence of anti-MAG neuropathy (Case 2). In case of poor response to bortezomib, standard chemoimmunotherapy (CIT), such as rituximab-bendamustine, represents an effective option (Case 1, 6, and 7). In our series, CIT generates durable responses more frequently in cases with amyloidogenic renal damage (Case 1, 5, and 7). CONCLUSION: In this illustrative case series, we confirm that serum creatinine levels and 24 h proteinuria are parameters that when altered should prompt the clinical suspicion of WM-related renal involvement, even if at present there are not precise cut-off levels recommending the execution of a renal biopsy. Studies with higher numerosity are needed to better clarify the pathological and clinical features of renal involvement during WM and to determine the potential benefit of different therapeutic regimens according to the histopathological subtypes.

Optimal strategies of oncolytic virus-bortezomib therapy via the apoptotic, necroptotic, and oncolysis signaling network.

Bortezomib and oncolytic virotherapy are two emerging targeted cancer therapies. Bortezomib, a proteasome inhibitor, disrupts protein degradation in cells, leading to the accumulation of unfolded proteins that induce apoptosis. On the other hand, virotherapy uses genetically modified oncolytic viruses (OVs) to infect cancer cells, trigger cell lysis, and activate anti-tumor response. Despite progress in cancer treatment, identifying administration protocols for therapeutic agents remains a significant concern, aiming to strike a balance between efficacy, minimizing toxicity, and administrative costs. In this work, optimal control theory was employed to design a cost-effective and efficient co-administration protocols for bortezomib and OVs that could significantly diminish the population of cancer cells via the cell death program with the NF$ \kappa $B-BAX-RIP1 signaling network. Both linear and quadratic control strategies were explored to obtain practical treatment approaches by adapting necroptosis protocols to efficient cell death programs. Our findings demonstrated that a combination therapy commencing with the administration of OVs followed by bortezomib infusions yields an effective tumor-killing outcome. These results could provide valuable guidance for the development of clinical administration protocols in cancer treatment.

An updated management approach of Pompe disease patients with high-sustained anti-rhGAA IgG antibody titers: experience with bortezomib-based immunomodulation.

Introduction: High sustained anti-rhGAA antibody titers (HSAT; ≥12,800) are directly linked to reduced efficacy of enzyme replacement therapy (ERT) and subsequent clinical deterioration in infantile-onset Pompe disease (IOPD). We have previously demonstrated the safety and effectiveness of a bortezomib-based immune-tolerance induction (ITI) regimen (bortezomib, rituximab, methotrexate, and IVIG) in eliminating HSAT. Methods: Here, we describe two IOPD cases (patients 6 and 8) who developed HSAT at 8 and 10 weeks on ERT despite transient low-dose methotrexate ITI administration in the ERT-naïve setting and were treated with a bortezomib-based ITI regimen, and we compare their courses to a series of six historical patients (patients 1-5, and 7) with a similar presentation who exemplify our evolving approach to treatment. Results: In total, patients 6 and 8 received 16 and 8 doses of bortezomib (4 doses=1 cycle) respectively reducing titers from 25,600 to seronegative, but differences in the course of their therapy were instructive regarding the optimal approach to initial treatment of HSAT; specifically, patient 6 was treated initially with only a single course of bortezomib rescue therapy, while patient 8 received two back-to-back courses. Patient 8 received IVIG therapy throughout the immunosuppression whereas patient 6 received IVIG therapy and was switched to subcutaneous IgG replacement. Patient 6 had a transient reduction in anti-rhGAA antibodies, after receiving a single initial cycle of bortezomib, but had a recurrence of high anti-rhGAA antibody titer after 160 weeks that required 3 additional cycles of bortezomib to ultimately achieve tolerance. In contrast, patient 8 achieved tolerance after being given two consecutive cycles of bortezomib during their initial treatment and had B cell recovery by week 54. Since the reduction in anti-rhGAA antibodies, both patients are doing well clinically, and have decreasing ALT, AST, and CK. No major infections leading to interruption of treatment were observed in either patient. The bortezomib-based ITI was safe and well-tolerated, and patients continue to receive ERT at 40 mg/kg/week. Discussion: These case studies and our previous experience suggest that to achieve an effective reduction of anti-rhGAA antibodies in the setting of HSAT, bortezomib should be initiated at the earliest sign of high anti-rhGAA antibodies with a minimum of two consecutive cycles as shown in the case of patient 8. It is important to note that, despite initiation of ERT at age 2.3 weeks, patient 8 quickly developed HSAT. We recommend close monitoring of anti-rhGAA antibodies and early intervention with ITI as soon as significantly elevated anti-rhGAA antibody titers are noted.

Impact of Genetic Polymorphisms in NF-ĸB2 and TRAF3 Genes on Response to Bortezomib-Based Therapy in Multiple Myeloma Patients.

BACKGROUND: Multiple myeloma (MM), being the second most common hematological malignancy, has garnered significant attention. The ubiquitin proteasomal pathway (UPP), crucial for normal cell function, plays a pivotal role in myeloma pathophysiology, especially with the advent of bortezomib (BTZ). Dysregulation of the UPP has implications ranging from developmental abnormalities to cancer. OBJECTIVES: This study aimed to delineate the clinical characteristics of newly diagnosed multiple myeloma patients and investigate the influence of single nucleotide polymorphisms (SNPs) in NF-ĸB2 and TRAF3 genes on the risk and treatment response to bortezomib-based chemotherapy. MATERIALS AND METHODS: Conducted at JIPMER, Pondicherry, this prospective study enrolled 184 participants, comprising cases and controls. DNA extraction from peripheral blood samples was followed by SNP analysis through Real-time Polymerase Chain Reaction. Patients were categorized into Good and Poor responders, and SNP associations with treatment response, response rates, and survival outcomes were assessed using chi-square and Kaplan-Meier analyses. RESULTS: The median age of participants was 55 years, with backache being the most prevalent symptom (66.3%). Hypercalcemia (22%), renal failure (8.7%), and bone fractures (45.7%) were also observed, alongside high prevalence of anemia. Notably, the frequency of the TRAF3 rs12147254 A allele was lower in cases compared to controls (31% vs. 49%, P-value=0.002). Poor responders exhibited higher frequencies of the GA+AA genotypes in TRAF3 rs12147254 (OR-3.882(1.629-9.251), P-value-0.002) and NFKB2 rs1056890 (OR-3.308(1.366-8.012), P-value-0.008) when compared to good responders. The GA+AA genotype in TRAF3 rs11160707 SNP correlated with improved progression-free survival. CONCLUSION: The study findings underscore a significant association between genetic polymorphisms and treatment response outcomes, suggesting their utility in prognostic determinations and clinical outcomes prediction in multiple myeloma patients.

A case report: Nonsecretory multiple myeloma presenting with bone pain.

RATIONALE: Nonsecretory multiple myeloma (NSMM) is a rare subtype of multiple myelom, occurring in 1% to 2% of multiple myelom and characterized by the inability of clonal plasma cells to synthesize or secrete immunoglobulins. We describe a 71-year-old male patient who began with bone pain and was referred to hospital several times, but was not properly diagnosed and effectively treated. PATIENT CONCERNS: A 71-year-old male patient visited our hematology department, complaining of lumbago for 1 year and back pain for half a year. DIAGNOSES: Low-dose whole-body bone computed tomography: multiple bone destruction of the sternum, ribs, multiple vertebrae and accessories of the spine, pelvis, bilateral humerus, and proximal femur. Monoclonal plasma cells accounted for 17.5% of nuclear cells in bone marrow puncture smear. Fluorescence in situ hybridization detected amplification of CKS1B (1q21) gene. Immunofixation electrophoresis negative. About 10.72% of monoclonal plasma cells were detected by flow cytometry. Finally, he was diagnosed with NSMM. INTERVENTIONS: The patients received VCD chemotherapy (bortezomib 1.3 mg/m2, d1, d4, d8, d11; cyclophosphamide 300 mg/m2, d1-2, d8-9; dexamethasone sodium phosphate 20 mg, d1-2, d4-5, d8-9, d11-12, once every 21 days). OUTCOMES: After 2 cycles of VCD treatment, the symptoms of bone pain were significantly relieved, and the efficacy was evaluated as partial response. Follow-up chemotherapy will continue to be completed on schedule. We will continue to follow up to further evaluate the overall survival and progression-free survival. LESSONS: This case shows that NSMM is easily missed or misdiagnosed.

Long-term outcomes by bone marrow B-cell depletion from the R2W trial of bortezomib with cyclophosphamide and rituximab in Waldenstrom macroglobulinaemia.

There remains a lack of consensus as to the most appropriate primary therapy in Waldenstrom macroglobulinemia (WM). We evaluated a novel bortezomib-based combination and developed a sensitive WM-specific flow cytometry assay (limit of detection 0.004% of leucocytes) to assess bone marrow (BM) response. Sixty treatment-naïve WM patients were enroled into this phase II trial and randomised (2:1) to receive cyclophosphamide and rituximab with either bortezomib (BRC) or fludarabine (FCR). The primary objective was to assess the overall response rate (ORR) in eligible patients receiving BRC (N = 41). An ORR of 97.6% (95%CI:87.1-99.9) was observed; 27 (65.9%) patients remain alive without progression after 62.6 months median follow-up, with 2-, 3- and 5-year progression-free survival (PFS) rates of 92.7% (95%CI:79.0-97.6), 80.5% (95%CI:64.8-89.7) and 65.5% (95%CI:48.8-77.9). Persistent WM B-cells were demonstrable in 19/38 patients at the end of treatment (median 0.24%, range 0.02-11.2%). PFS was markedly longer in patients with BM B-cell depletion (<0.004%) compared to those who had persistent BM B-cells detectable at end of treatment (HR = 0.06, 95%CI:0.01-0.47, p < 0.001), and remained independently associated after adjusting for baseline risk stratification or investigator-assessed response. BRC is a tolerable, highly efficacious regimen for treatment-naïve WM patients. BM B-cell depletion is independently associated with patient outcomes.

Treatment Pattern and Outcome of Newly Diagnosed Multiple Myeloma Patients in a Resource-Limited Setting.

BACKGROUND: Multiple myeloma is the third most common hematologic malignancy in Malaysia. The introduction of novel agents over the past decades has improved patient outcome and survival substantially. However, these agents incur significant economic burden, thus leading to limited use in less developed countries. This study aims to report on the real-world treatment pattern and outcome of newly diagnosed multiple myeloma (NDMM) patients from a resource-constraint setting. METHODS: This is a retrospective study on NDMM patients diagnosed between 1 January 2008 and 31 December 2022 in a single academic center. Patients' demographic and treatment details were included for analysis of progression free survival (PFS) and overall survival (OS). RESULTS: One hundred and thirty-six NDMM patients with a median age of 64.0 years (ranged from 38 to 87 years old) were included. Bortezomib-containing regimens were the most commonly used induction agent, followed by thalidomide. Almost half of the patients (47.1%) achieved very good partial response (VGPR) or complete remission (CR), while 31.6% achieved partial response (PR). Bortezomib containing regimen was associated with significantly deeper and more rapid response, (p=0.001 and p=0.017, respectively) when compared to other agents. Only 22.8% of these patients proceeded to upfront autologous haematopoietic stem cell transplantation.  The median OS and PFS were 60.0 months and 25.0 months, respectively. Best initial response and upfront autologous stem cell transplantation (ASCT) were significantly associated with better PFS. CONCLUSION: Achieving at least a VGPR significantly associated with better outcome in NDMM patients. In a resource constrain country, we recommend incorporating bortezomib in the induction therapy followed with an upfront ASCT.

Immune profiles to predict bortezomib-based treatment response for multiple myeloma patients.

BACKGROUND: To evaluate the distribution of bone marrow immune cell subsets and their correlation with treatment efficacy in patients with multiple myeloma (MM). METHODS: We analyzed the bone marrow lymphocyte subsets of 186 newly diagnosed MM patients at diagnosis and their correlation with clinical characteristics. In our study, eight-color flow cytometry, a method commonly used to detect plasma cell phenotypes, was used to analyze seven bone marrow immune cell groups by change gate-strategy. RESULTS: First, for all the 7 immune cell groups, the percentage of immature B cells was significantly lower in stage III patients than in stage I patients, while the trend was reversed in memory B cells in both the International Staging System(p = 0.004) and Revised International Staging System(p = 0.018). Second, the percentage of naïve B cells were significantly lower in patients with severe anemia, while the percentage of memory B cells had reversed trend. The percentage of immature B cells were lower in patients with Cr ≥ 2 mg/dL than in patients with Cr < 2 mg/dL. Then we followed the treatment efficacy of 152 patients who received four cycles of induction therapy (bortezomib + dexamethasone or bortezomib + lenalidomide + dexamethasone) and analyzed the relationship between bone marrow lymphocyte subsets at the initial stage and treatment response datasets. We found that both the percentage of B cells(p＜0.001) and immature B(p = 0.002) were increased in patients who achieved very good partial remission(VGPR) after four cycles of induction therapy. The ROC results indicated the combination of the multiple immune subgroups had predictive values (AUC = 0.802, p<0.001) in the treatment effect after four cycles of induction therapy. CONCLUSIONS: Overall, these results suggest that the analysis of lymphocyte subsets along with plasma cell immunophenotyping could be a potential index for determining the prognosis of MM patients.

[Multiple myeloma with myelofibrosis at diagnosis and aggressive extramedullary relapse after autologous stem cell transplantation].

A 66-year-old man was diagnosed with symptomatic IgG-λ multiple myeloma based on the presence of anemia, thrombocytopenia, renal dysfunction, and a tumor on the right sixth rib. Bone marrow aspiration yielded a dry tap and biopsy revealed myelofibrosis grade 2. Partial response was achieved with Bd (bortezomib and dexamethasone) and VRd (bortezomib, lenalidomide, and dexamethasone). The patient received autologous stem cell transplantation, but the myeloma relapsed 3 months later, and liver tumors developed as well. DKd (daratumumab, carfilzomib, and dexamethasone) was administered, but the patient died due to disease progression. Autopsy revealed multiple extramedullary lesions in the liver, spleen, gallbladder, adrenal glands, kidneys, and multiple lymph nodes, as well as ascites.

Spatial sequestration of activated-caspase 3 in aggresomes mediates resistance of neuroblastoma cell to bortezomib treatment.

Neuroblastoma (NB) is the most common pediatric tumor and is currently treated by several types of therapies including chemotherapies, such as bortezomib treatment. However, resistance to bortezomib is frequently observed by mechanisms that remain to be deciphered. Bortezomib treatment leads to caspase activation and aggresome formation. Using models of patients-derived NB cell lines with different levels of sensitivity to bortezomib, we show that the activated form of caspase 3 accumulates within aggresomes of NB resistant cells leading to an impairment of bortezomib-induced apoptosis and increased cell survival. Our findings unveil a new mechanism of resistance to chemotherapy based on an altered subcellular distribution of the executioner caspase 3. This mechanism could explain the resistance developed in NB patients treated with bortezomib, emphasizing the potential of drugs targeting aggresomes.

[Efficacy and Safety of Bortezomib or Thalidomide Combined with rhEPO in the Treatment of Multiple Myeloma].

OBJECTIVE: To explore the efficacy and safety of bortezomib or thalidomide combined with recombinant human erythropoietin (rhEPO) in the treatment of multiple myeloma (MM). METHODS: A total of 80 patients with MM who were treated in the Second People's Hospital of Wuhu from January 2013 to December 2018 were selected as the research subjects, and they were divided into bortezomib group (n=40) and thalidomide group (n=40) by the simple randomization method. The bortezomib group received bortezomib regimen combined with rhEPO therapy, and the thalidomide group was given thalidomide regimen combined with rhEPO therapy, and all patients were treated for 3 courses with every 3 weeks as a course of treatment. The clinical efficacy after 3 courses of treatment, and tumor-related biochemical indicators [lactate dehydrogenase (LDH), ß2-microglobulin (ß2-MG), vascular endothelial growth factor (VEGF), apoptosis inhibitory protein Survivin], bone marrow-related indicators [serum M-protein, bone marrow plasma cells, hemoglobin (Hb)] and coagulation function indicators [activated partial thromboplastin time (APTT), prothrombin time (PT), plasminogen activator inhibitor (PAI), total circulating microparticles (TMPs)] before treatment and after 3 courses of treatment were compared between the two groups of patients. The occurrence of adverse reactions during the treatment in the two groups of patients was recorded. RESULTS: After 3 courses of treatment, the ORR rate of 92.5% in bortezomib group was higher than 90.0% in thalidomide group, but the difference was not statistically significant (P >0.05). The levels of LDH, ß2-MG, VEGF, Survivin, serum M-protein, bone marrow plasma cells, APTT, PT, PAI and TMPs in the two groups after 3 courses of treatment were significantly lower or shorter than those before treatment, and the above indicators in bortezomib group were significantly lower or shorter than those in thalidomide group (P <0.05). After 3 courses of treatment, the expression level of Hb in the two groups was significantly higher than that before treatment, and the Hb level in bortezomib group was significantly higher than that in thalidomide group (P <0.05). During the treatment process, the incidence rates of adverse reactions in bortezomib group were significantly lower than those in thalidomide group (P <0.05). CONCLUSION: Thalidomide regimen or bortezomib regimen combined with rhEPO has similar clinical efficacy on MM, but bortezomib regimen combined with rhEPO is more prominent and safer on improving tumor-related biochemical indicators, bone marrow-related indicators and coagulation status in patients with MM.

[Risk Factors and the Effect of Antiviral Prophylaxis for Herpes Zoster in Multiple Myeloma Patients].

OBJECTIVE: To study the incidence and risk factors of herpes zoster in patients with multiple myeloma and to evaluate the preventive effect of antiviral therapy. METHODS: The clinical features of multiple myeloma patients with herpes zoster were retrospectively analyzed, the risk factors of herpes zoster and the effect of antiviral prophylaxis were analyzed. RESULTS: Among 180 patients with multiple myeloma, 23 cases developed herpes zoster (12.8%). The incidence of herpes zoster was 19.1% in patients with renal dysfunction and 23.5% after autologous hematopoietic stem cell transplantation (ASCT). The incidence of herpes zoster was higher in patients receiving bortezomib-containing regimens (21/137, 15.3%) than that in those without bortezomib (2/43, 4.7%), but there was no statistical difference (P =0.067). Antiviral prophylaxis was associated with fewer zoster infections, 8/111(7.2%) developed herpes zoster in patients who received antiviral prophylaxis, and 15/69 (21.7%) in those receiving no prophylaxis(P =0.005). 65.2% of patients with herpes zoster did not receive antiviral prophylaxis. Multivariate analysis showed that bortezomib treatment, AHSCT and renal dysfunction were independent risk factors for multiple myeloma with herpes zoster, while antiviral prophylaxis was independently associated with reducing the risk of herpes zoster. Herpes zoster had no effect on OS in patients with multiple myeloma. CONCLUSION: The risk of herpes zoster in multiple myeloma patients was increased. Antiviral prophylaxis can reduce the risk of herpes zoster in patients on bortezomib-based therapy.

Real-world treatment patterns and outcomes for patients with multiple myeloma in Denmark, Finland and Sweden: An analysis using linked Nordic registries.

AIM: The Health outcomes and Understanding of MyelomA multi-National Study (HUMANS) was a large-scale, retrospective study conducted across Denmark, Finland and Sweden using linked data from national registries. We describe the characteristics, treatment patterns and clinical outcomes for patients with newly diagnosed multiple myeloma (NDMM) over 2010-2018. METHODS: Patients with NDMM who received MM-specific, first-line treatments, were categorised by treatment (autologous stem cell transplantation [ASCT] or a combination chemotherapy regimen based on bortezomib, lenalidomide or melphalan-prednisolone-thalidomide). RESULTS: 11,023 patients received treatment over 2010-2018. Time between diagnosis and treatment was shortest in Denmark (0.9 months), then Sweden (2.9 months) and Finland (4.6 months). Around one third of patients underwent ASCT. Lenalidomide-based regimens were prescribed to 23-28% of patients in Denmark and Finland, versus 12% in Sweden. Patients receiving lenalidomide had the longest wait for treatment, from 3.2 months (Denmark) to 12.1 months (Sweden). Treatment persistence was highest among patients receiving melphalan-prednisolone-thalidomide (7-8 months) in Finland and Sweden and lowest among those receiving bortezomib (3.5 months) in Finland. Overall survival (OS) was longest among patients with ASCT (7-10 years). Among patients receiving chemotherapy, OS (from diagnosis/treatment initiation), varied between cohorts. In a sensitivity analysis excluding patients with smouldering MM, OS decreased for all; for patients receiving bortezomib or lenalidomide, OS from diagnosis was 40-49 and 27-54 months, respectively. CONCLUSIONS: This population-based study of patients with NDMM receiving first-line MM-specific treatment, provides real-world data on treatment patterns and outcomes to complement data from randomised clinical trials.