A single-day polychemotherapy regimen with proteasome inhibitor combinations for relapsed/refractory myeloma in the era of novel therapies.

PCAB (prednisone, cyclophosphamide, doxorubicin, carmustine) is a single-day regimen previously used for induction and now in relapsed/refractory multiple myeloma (RRMM). We retrospectively analysed the outcomes of 85 patients from five Australian centres. These included 30 patients (35.3%) who received PCAB with one additional agent (bortezomib most frequently). Median age of the patients was 65 years (37-80), with a median of four (1-8) prior lines of therapy. ORR was 37% (CR 4.9%). Median progression free survival and overall survival were 4.4 months (95% CI 3.5-6.7) and 7.4 months (95% CI 6.4-10.2), respectively. Extramedullary disease (EMD) was associated with shorter survival. Grade 3 or 4 cytopenia and febrile neutropenia occurred in 76.2% and 39.1%, respectively, with six (7.1%) treatment-related mortalities. Median inpatient stay was 3.3 days/28-day cycle (IQR 0.6-13), and for patients who died, a median of 20.2% of days alive were spent inpatient (IQR 6.4-39.1%). Three patients were successfully bridged to CAR T-cell therapy using PCAB, despite being penta-exposed and having EMD. PCAB may be considered as a useful salvage therapy amongst other polychemotherapy regimens in late relapse. Further studies is warranted to investigate and define its role as a bridging therapy to novel therapeutics.

Serum Free Light Chain Kinetics Is Predictive of Renal Response in Myeloma Patients With Renal Impairment-An ALLG Trial of Carfilzomib-Dexamethasone Therapy in Frontline and Relapse.

BACKGROUND AND PURPOSE: Renal impairment (RI) confers adverse prognosis in myeloma; its reversal and avoidance of dialysis are crucial. We investigated whether serum free light chain (SFLC) measurements can predict renal outcome, to enable change in therapy to optimize prognosis and avoid dialysis. PATIENTS AND METHODS: We investigated 36 myeloma patients (17 newly diagnosed [ND]; 19 relapsed refractory [RR]; with median of 5 prior lines) with eGFR 15-40 ml/min treated with carfilzomib (Cfz)-dexamethasone to determine whether SFLC kinetics can predict renal outcomes, and assess efficacy and tolerability. RESULTS: The change in involved SFLC at Cycle 2 Day 1 was significantly correlated with renal function; for every one log10 reduction in involved SFLC, eGFR increased by 9.0-15.0 mL/min at cycles 2-4, with SFLC reduction of 54%-78%. At a median follow-up of 30.6 months, renal outcomes were favorable-CRrenal 25%, MRrenal 36%. Disease responses (ND 100%, RR 75%), progression-free survival (ND 32.2 months, RR 11.1 months) and overall survival (ND not reached, RR 42.0 months) were comparable to patients without RI. There was significant toxicity, including Cfz-related cardiac impairment of 20% within a cohort with high co-morbidity, and a high incidence of infections. CONCLUSION: We propose that one log10 reduction in involved SFLC at Cycle 2 Day 1 is an appropriate target for reducing the risk of dialysis in myeloma patients with RI; below this threshold patients may benefit from a change in therapy. While Cfz-dexamethasone achieved favorable renal and disease outcomes, toxicity can be significant in this vulnerable cohort.

Single-cell analysis of the CD8+ T-cell compartment in multiple myeloma reveals disease specific changes are chiefly restricted to a CD69- subset suggesting potent cytotoxic effectors exist within the tumor bed.

Multiple myeloma (MM) is an incurable disease of the bone marrow (BM) characterized by the uncontrolled proliferation of neoplastic plasma cells. While CD8+ T cells have an established role in disease control, few studies have focused on these cells within the MM tumor microenvironment (TME). We analyzed CD8+ T cells in the BM and peripheral blood (PB) of untreated patients with MM and non-myeloma controls using flow cytometry, mass cytometry and single-cell RNA sequencing, using several novel bioinformatics workflows. Inter-tissue differences were most evident in the differential expression of Granzymes B and K, which were strongly associated with two distinct subsets of CD8+ T cells delineated by the expression of CD69, accounting for roughly 50% of BM-CD8+ T cells of all assessed cohorts. While few differences were observable between health and disease in the BM-restricted CD8CD69+ T-cell subset, the CD8+CD69- T-cell subset in the BM of untreated MM patients demonstrated increased representation of highly differentiated effector cells and evident compositional parallels between the PB, absent in age-matched controls, where a marked reduction of effector cells was observed. We demonstrate the transcriptional signature of BM-CD8+ T cells from patients with MM more closely resembles TCR-activated CD8+ T cells from age-matched controls than their resting counterparts.

The importance of frailty assessment in multiple myeloma: a position statement from the Myeloma Scientific Advisory Group to Myeloma Australia.

Multiple myeloma (MM) is a disease of older people, yet factors relating to comorbidity and frailty may threaten treatment tolerability for many of this heterogenous group. There has been increasing interest in defining specific and clinically relevant frailty assessment tools within the MM population, with the goal of using these frailty scores, not just as a prognostic instrument, but also as a predictive tool to allow for a frailty-adapted treatment approach. This paper reviews the various frailty assessment frameworks used in the evaluation of patients with MM, including the International Myeloma Working Group Frailty Index (IMWG-FI), the Mayo Frailty Index and the simplified frailty scale. While the IMWG-FI remains the most widely accepted tool, the simplified frailty scale is the most user-friendly in busy day-to-day clinics based on its ease of use. This paper summarises the recommendations from the Myeloma Scientific Advisory Group (MSAG) of Myeloma Australia, on the use of frailty assessment tools in clinical practice and proposes a frailty-stratified treatment algorithm to aid clinicians in tailoring therapy for this highly heterogeneous patient population.

Treatment of patients with Waldenström macroglobulinaemia: clinical practice update from the Myeloma Foundation of Australia Medical and Scientific Advisory Group.

Waldenström macroglobulinaemia (WM) is an indolent B-cell malignancy characterised by the presence of IgM paraprotein, bone marrow infiltration by clonal small B lymphocytes with plasmacytic differentiation and the MYD88 L265P mutation in >90% of cases. Traditionally, WM has been treated with chemoimmunotherapy. Recent trials have demonstrated the efficacy and safety of Bruton tyrosine kinase inhibitors in WM, both as monotherapy and in combination with other drugs. There is emerging evidence on the use of other agents including B-cell lymphoma 2 inhibitors and on the treatment of rare presentations of WM. In this update, the Medical and Scientific Advisory Group of Myeloma Australia reviews the available evidence on the treatment of WM since the last publication in 2017 and provides specific recommendations to assist Australian clinicians in the management of this disease.

Alcohol and tobacco use and risk of multiple myeloma: A case-control study.

Multiple myeloma (MM) is the second most common hematological cancer and causes significant mortality and morbidity. Knowledge regarding modifiable risk factors for MM remains limited. This analysis of an Australian population-based case-control family study investigates whether smoking or alcohol consumption is associated with risk of MM and related diseases. Incident cases (n = 789) of MM were recruited via cancer registries in Victoria and New South Wales. Controls (n = 1,113) were either family members of cases (n = 696) or controls recruited for a similarly designed study of renal cancers (n = 417). Adjusted odds ratios (OR) and 95% confidence intervals (CI) were estimated using unconditional multivariable logistic regression. Heavy intake (>20 g ethanol/day) of alcohol had a lower risk of MM compared with nondrinkers (OR = 0.68, 95% CI: 0.50-0.93), and there was an inverse dose-response relationship for average daily alcohol intake (OR per 10 g ethanol per day = 0.92, 95% CI: 0.86-0.99); there was no evidence of an interaction with sex. There was no evidence of an association with MM risk for smoking-related exposures (p > 0.18). The associations between smoking and alcohol with MM are similar to those with non-Hodgkin lymphoma. Further research into potential underlying mechanisms is warranted.

An international observational study to assess the impact of the Omicron variant emergence on the clinical epidemiology of COVID-19 in hospitalised patients

BackgroundWhilst timely clinical characterisation of infections caused by novel SARS-CoV-2 variants is necessary for evidence-based policy response, individual-level data on infecting variants are typically only available for a minority of patients and settings. MethodsHere, we propose an innovative approach to study changes in COVID-19 hospital presentation and outcomes after the Omicron variant emergence using publicly available population-level data on variant relative frequency to infer SARS-CoV-2 variants likely responsible for clinical cases. We apply this method to data collected by a large international clinical consortium before and after the emergence of the Omicron variant in different countries. ResultsOur analysis, that includes more than 100,000 patients from 28 countries, suggests that in many settings patients hospitalised with Omicron variant infection less often presented with commonly reported symptoms compared to patients infected with pre-Omicron variants. Patients with COVID-19 admitted to hospital after Omicron variant emergence had lower mortality compared to patients admitted during the period when Omicron variant was responsible for only a minority of infections (odds ratio in a mixed-effects logistic regression adjusted for likely confounders, 0.67 [95% confidence interval 0.61 - 0.75]). Qualitatively similar findings were observed in sensitivity analyses with different assumptions on population-level Omicron variant relative frequencies, and in analyses using available individual-level data on infecting variant for a subset of the study population. ConclusionsAlthough clinical studies with matching viral genomic information should remain a priority, our approach combining publicly available data on variant frequency and a multi-country clinical characterisation dataset with more than 100,000 records allowed analysis of data from a wide range of settings and novel insights on real-world heterogeneity of COVID-19 presentation and clinical outcome.

Consensus guidelines and recommendations for infection prevention in multiple myeloma: a report from the International Myeloma Working Group.

Infection remains the leading cause of morbidity and mortality in patients with multiple myeloma because of the cumulative effect of disease, treatment, and host-related factors. Given that infectious risk is cumulative through the course of the disease, preventing infections is paramount. Optimal preventive strategies include vaccination against common pathogens, antimicrobial prophylaxis, infection control measures, and immunoglobulin replacement in a small subset of patients; however, there are no universally accepted guidelines for infection prevention. This Review provides a consensus statement from a panel of 36 experts with global representation, which was convened by The International Myeloma Society to review existing literature and current guidelines, address issues associated with the risk of infection and prevention of infectious complications in multiple myeloma in the context of emerging therapies, and offer recommendations for preventing these complications.

Imaging of patients with multiple myeloma and associated plasma cell disorders: consensus practice statement by the Medical Scientific Advisory Group to Myeloma Australia.

Imaging modalities for multiple myeloma (MM) have evolved to enable earlier detection of disease. Furthermore, the diagnosis of MM requiring therapy has recently changed to include disease prior to bone destruction, specifically the detection of focal bone lesions. Focal lesions are early, abnormal areas in the bone marrow, which may signal the development of subsequent lytic lesions that typically occur within the next 18-24 months. Cross-sectional imaging modalities are more sensitive for the detection and monitoring of bone and bone marrow disease and are now included in the International Myeloma Working Group current consensus criteria for initial diagnosis and treatment response assessment. The aim of this consensus practice statement is to review the evidence supporting these modalities. A more detailed Position Statement can be found on the Myeloma Australia website.

Treg and Oligoclonal Expansion of Terminal Effector CD8+ T Cell as Key Players in Multiple Myeloma.

The classical paradigm of host-tumor interaction, i.e. elimination, equilibrium, and escape (EEE), is reflected in the clinical behavior of myeloma which progresses from the premalignant condition, Monoclonal Gammopathy of Unknown Significance (MGUS). Despite the role of other immune cells, CD4+ regulatory T cells (Treg) and cytotoxic CD8+ T cells have emerged as the dominant effectors of host control of the myeloma clone. Progression from MGUS to myeloma is associated with alterations in Tregs and terminal effector CD8+ T cells (TTE). These changes involve CD39 and CD69 expression, affecting the adenosine pathway and residency in the bone marrow (BM) microenvironment, together with oligoclonal expansion within CD8+ TTE cells. In this mini-review article, in the context of earlier data, we summarize our recent understanding of Treg involvement in the adenosine pathway, the significance of oligoclonal expansion within CD8+ TTE cells and BM-residency of CD8+ TTE cells in MGUS and newly diagnosed multiple myeloma patients.

Inverse relationship between oligoclonal expanded CD69- TTE and CD69+ TTE cells in bone marrow of multiple myeloma patients.

CD8+CD57+ terminal effector T (TTE) cells are a component of marrow-infiltrating lymphocytes and may contribute to the altered immune responses in multiple myeloma (MM) patients. We analyzed TTE cells in the bone marrow (BM) and peripheral blood (PB) of age-matched controls and patients with monoclonal gammopathy of undetermined significance (MGUS), smoldering MM (SMM), and newly diagnosed (ND) MM using flow cytometry, mass cytometry, and FlowSOM clustering. TTE cells are heterogeneous in all subjects, with BM containing both CD69- and CD69+ subsets, while only CD69- cells are found in PB. Within the BM-TTE compartment, CD69- and CD69+ cells are found in comparable proportions in controls, while CD69- cells are dominant in MGUS and SMM and predominantly either CD69- or CD69+ cells in NDMM. A positive relationship between CD69+TTE and CD69-TTE cells is observed in the BM of controls, lost in MGUS, and converted to an inverse relationship in NDMM. CD69-TTE cells include multiple oligoclonal expansions of T-cell receptor/Vß families shared between BM and PB of NDMM. Oligoclonal expanded CD69-TTE cells from the PB include myeloma-reactive cells capable of killing autologous CD38hi plasma cells in vitro, involving degranulation and high expression of perforin and granzyme. In contrast to CD69-TTE cells, oligoclonal expansions are not evident within CD69+TTE cells, which possess low perforin and granzyme expression and high inhibitory checkpoint expression and resemble T resident memory cells. Both CD69-TTE and CD69+TTE cells from the BM of NDMM produce large amounts of the inflammatory cytokines interferon-γ and tumor necrosis factor α. The balance between CD69- and CD69+ cells within the BM-TTE compartment may regulate immune responses in NDMM and contribute to the clinical heterogeneity of the disease.

A liquid biopsy to detect multidrug resistance and disease burden in multiple myeloma.

Multiple myeloma is an incurable cancer of bone marrow plasma cells, with a 5-year survival rate of 43%. Its incidence has increased by 126% since 1990. Treatment typically involves high-dose combination chemotherapy, but therapeutic response and patient survival are unpredictable and highly variable-attributed largely to the development of multidrug resistance (MDR). MDR is the simultaneous cross-resistance to a range of unrelated chemotherapeutic agents and is associated with poor prognosis and survival. Currently, no clinical procedures allow for a direct, continuous monitoring of MDR. We identified circulating large extracellular vesicles (specifically microparticles (MPs)) that can be used to monitor disease burden, disease progression and development of MDR in myeloma. These MPs differ phenotypically in the expression of four protein biomarkers: a plasma-cell marker (CD138), the MDR protein, P-glycoprotein (P-gp), the stem-cell marker (CD34); and phosphatidylserine (PS), an MP marker and mediator of cancer spread. Elevated levels of P-gp+ and PS+ MPs correlate with disease progression and treatment unresponsiveness. Furthermore, P-gp, PS and CD34 are predominantly expressed in CD138- MPs in advanced disease. In particular, a dual-positive (CD138-P-gp+CD34+) population is elevated in aggressive/unresponsive disease. Our test provides a personalised liquid biopsy with potential to address the unmet clinical need of monitoring MDR and treatment failure in myeloma.

Mass Cytometry Discovers Two Discrete Subsets of CD39-Treg Which Discriminate MGUS From Multiple Myeloma.

Multiple Myeloma (MM) is preceded by the clinically stable condition monoclonal gammopathy of undetermined significance (MGUS). Critical immune events that discriminate MGUS from newly diagnosed MM (ND)MM patients remain unknown, but may involve changes in the regulatory T cell (Treg) compartment that favor myeloma growth. To address this possibility, we used mass cytometry and the unsupervised clustering algorithm Flow self-organizing map (FlowSOM) to interrogate the distribution of multiple subsets within CD25+CD127low/negTreg in matched bone marrow (BM) and peripheral blood (PB) of MGUS and NDMM patients. Both mass cytometry and flow cytometry confirmed a trend toward prevalence of CD39-Treg within the Treg compartment in BM and PB of NDMM patients compared to CD39-Treg in MGUS patients. FlowSOM clustering displayed a phenotypic organization of Treg into 25 metaclusters that confirmed Treg heterogeneity. It identified two subsets which emerged within CD39-Treg of NDMM patients that were negligible or absent in CD39-Treg of MGUS patients. One subset was found in both BM and PB which phenotypically resembled activated Treg based on CD45RO, CD49d, and CD62L expression; another subset resembled BM-resident Treg based on its tissue-resident CD69+CD62L-CD49d- phenotype and restricted location within the BM. Both subsets co-expressed PD-1 and TIGIT, but PD-1 was expressed at higher levels on BM-resident Treg than on activated Treg. Within BM, both subsets had limited Perforin and Granzyme B production, whilst activated Treg in PB acquired high Perforin and Granzyme B production. In conclusion, the use of mass cytometry and FlowSOM clustering discovered two discrete subsets of CD39-Treg which are discordant in MGUS and NDMM patients and may be permissive of myeloma growth which warrants further study. Understanding the regulatory properties of these subsets may also advance MGUS and MM diagnosis, prognosis, and therapeutic implications for MM patients.

Biology and therapy of multiple myeloma.

Genetic sequencing of the myeloma genome has not revealed a specific disease-determining genetic alteration. Multiple disease subclones exist at diagnosis and vary in clinical importance with time and drug sensitivity. New diagnostic criteria have identified indications for early introduction of therapy. Autologous stem cell transplantation remains an essential component of therapy in young and fit patients. The use of continual suppressive (maintenance) therapy has been established as an important component in therapy. Immune therapies and the harnessing of the innate immune system offer great promise for future treatments. Since 2005, quality of life, supportive therapies, and survival have dramatically improved over a decade of remarkable progress. The common manifestations of multiple myeloma, such as bone pain, fatigue and weight loss, may be non-specific and are often initially ignored or missed by patients and medical practitioners.

Phase 3 study of subcutaneous bortezomib, thalidomide, and prednisolone consolidation after subcutaneous bortezomib-based induction and autologous stem cell transplantation in patients with previously untreated multiple myeloma: the VCAT study.

Efficacy and safety of bortezomib-based consolidation following ASCT were investigated in newly diagnosed multiple myeloma patients from Australia, Korea, and China. Patients received three cycles of bortezomib-cyclophosphamide-dexamethasone induction followed by high-dose therapy/ASCT, then were randomized (1:1) to consolidation with TP (thalidomide 100 mg/d for ≤12 months/until disease progression; prednisolone 50 mg on alternate days indefinitely/until disease progression; n = 100) or VTP (subcutaneous bortezomib 1.3 mg/m2 every 2 weeks for 32 weeks, plus TP; n = 103). The hypothesized difference in CR + VGPR rate (after ≤12 months consolidation therapy) was not met. The rate of CR + VGPR was numerically higher with VTP versus TP; however, this was not statistically significant (85.7% versus 77.1%; rate difference 8.6%; 95% confidence interval -2.3%-19.5%; p = .122). Secondary efficacy outcomes were similar between treatment arms. Addition of bortezomib to TP consolidation was associated with limited additional toxicity but did not significantly improve efficacy versus TP.

A blood dendritic cell vaccine for acute myeloid leukemia expands anti-tumor T cell responses at remission.

Only modest advances in AML therapy have occurred in the past decade and relapse due to residual disease remains the major challenge. The potential of the immune system to address this is evident in the success of allogeneic transplantation, however this leads to considerable morbidity. Dendritic cell (DC) vaccination can generate leukemia-specific autologous immunity with little toxicity. Promising results have been achieved with vaccines developed in vitro from purified monocytes (Mo-DC). We now demonstrate that blood DC (BDC) have superior function to Mo-DC. Whilst BDC are reduced at diagnosis in AML, they recover following chemotherapy and allogeneic transplantation, can be purified using CMRF-56 antibody technology, and can stimulate functional T cell responses. While most AML patients in remission had a relatively normal T cell landscape, those who had received fludarabine as salvage therapy have persistent T cell abnormalities including reduced number, altered subset distribution, failure to expand, and increased activation-induced cell death. Furthermore, PD-1 and TIM-3 are increased on CD4T cells in AML patients in remission and their blockade enhances the expansion of leukemia-specific T cells. This confirms the feasibility of a BDC vaccine to consolidate remission in AML and suggests it should be tested in conjunction with checkpoint blockade.

Quality of Patient-Centered Care Provided to Patients Attending Hematological Cancer Treatment Centers.

The Institute of Medicine has recommended that improvements are needed in patient-centered care. This study examined hematological cancer patients' perceptions of which aspects of cancer care were being delivered well and areas that required improvement, and whether patient characteristics, or the treatment center they attended, were associated with quality of patient-centered care. Participants were recruited via three Australian hematological cancer treatment centers and completed a paper-and-pen survey assessing sociodemographic, disease, and psychological and treatment characteristics at recruitment. A second survey that contained the Quality of Patient-Centered Cancer Care measure was completed one month after recruitment (n = 215). The most frequently delivered feature of patient-centered cancer care was hospital staff showing respect for patients (91.0%). The area of care reported most commonly as not being delivered was hospital staff helping the patient find other cancer patients to talk to (29.8%). Patients without depression reported higher perceived quality of treatment decision-making, co-ordinated and integrated care, emotional support, follow-up care, respectful communication, and cancer information than patients with depression. The treatment center that was attended was associated only with the quality of cancer information patients received. Privacy issues may hinder staff connecting patients directly but this could be overcome via referrals to cancer organizations that offer peer support services.

Carfilzomib-dexamethasone versus subcutaneous or intravenous bortezomib in relapsed or refractory multiple myeloma: secondary analysis of the phase 3 ENDEAVOR study.

This is a secondary analysis of the phase 3 ENDEAVOR study comparing relapsed and/or refractory multiple myeloma (RRMM) patients receiving carfilzomib-dexamethasone (Kd) with those receiving subcutaneous (SC) bortezomib with dexamethasone (Vd) or intravenous (IV) Vd. Of Kd-treated patients, 356 Kd were pre-selected (by physician prior to randomization if to be randomized to Vd) for SC Vd (Kd [SC Vd]) and 108 for IV Vd (Kd [IV Vd], respectively. Of Vd-treated patients, 360 received SC Vd and 75 IV Vd. Kd (SC Vd) median PFS was not reached; SC Vd was 9.5 months. Median PFS for Kd (IV Vd) and IV Vd were 22.2 and 8.5 months, respectively. Median PFS was significantly longer and response rates were higher for Kd versus retreatment with bortezomib (SC or IV Vd) and in bortezomib naive patients. Overall, Kd was superior to Vd in RRMM regardless of route of bortezomib administration or prior bortezomib exposure.

Carfilzomib or bortezomib in relapsed or refractory multiple myeloma (ENDEAVOR): an interim overall survival analysis of an open-label, randomised, phase 3 trial.

BACKGROUND: The phase 3 ENDEAVOR trial was a head-to-head comparison of two proteasome inhibitors in patients with relapsed or refractory multiple myeloma. Progression-free survival was previously reported to be significantly longer with carfilzomib administered in combination with dexamethasone than with bortezomib and dexamethasone in an interim analysis. The aim of this second interim analysis was to compare overall survival between the two treatment groups. METHODS: ENDEAVOR was a phase 3, open-label, randomised controlled trial in patients with relapsed or refractory multiple myeloma. Patients were recruited from 198 hospitals and outpatient clinics in 27 countries in Europe, North America, South America, and the Asia-Pacific region. Patients were aged 18 years or older, had relapsed or refractory multiple myeloma, and had received between one and three previous lines of therapy. Patients were randomly assigned (1:1) to receive carfilzomib and dexamethasone (carfilzomib group) or bortezomib and dexamethasone (bortezomib group) through a blocked randomisation scheme (block size of four), stratified by International Staging System stage, previous lines of treatment, previous proteasome inhibitor therapy, and planned route of bortezomib delivery if assigned to the bortezomib group. Carfilzomib (20 mg/m2 on days 1 and 2 of cycle 1; 56 mg/m2 thereafter) was given as a 30-min intravenous infusion on days 1, 2, 8, 9, 15, and 16 of 28-day cycles; bortezomib (1·3 mg/m2) was given as an intravenous bolus or subcutaneous injection on days 1, 4, 8, and 11 of 21-day cycles. Dexamethasone (20 mg oral or intravenous infusion) was given on days 1, 2, 8, 9, 15, 16, 22, and 23 in the carfilzomib group and on days 1, 2, 4, 5, 8, 9, 11, and 12 in the bortezomib group. The primary endpoint of ENDEAVOR, progression-free survival, has been previously reported. A stratified log-rank test was used to compare overall survival between treatment groups for this prospectively planned second interim analysis. Efficacy assessments were done in all randomly assigned patients (the intention-to-treat population) and the safety analysis included patients who received at least one dose of study treatment. This trial is registered with ClinicalTrials.gov, number NCT01568866, and is no longer enrolling patients. FINDINGS: Between June 20, 2012, and June 30, 2014, 1096 patients were assessed for eligibility, of whom 929 were randomly assigned (464 to the carfilzomib group and 465 to the bortezomib group). The cutoff date for this prespecified interim analysis was Jan 3, 2017. Median overall survival was 47·6 months (95% CI 42·5-not evaluable) in the carfilzomib group versus 40·0 months (32·6-42·3) in the bortezomib group (hazard ratio 0·791 [95% CI 0·648-0·964], one-sided p=0·010). Grade 3 or worse adverse events were reported in 377 (81%) of 463 patients in the carfilzomib group and 324 (71%) of 456 patients in the bortezomib group, and serious adverse events in 273 (59%) patients in the carfilzomib group and 182 (40%) in the bortezomib group. The most frequent grade 3 or worse adverse events were anaemia (76 [16%] of 463 patients in the carfilzomib group vs 46 [10%] of 456 patients in the bortezomib group), hypertension (67 [15%] vs 15 [3%]), pneumonia (42 [9%] vs 39 [9%]), thrombocytopenia (41 [9%] vs 43 [9%]), fatigue (31 [7%] vs 35 [8%]), dyspnoea (29 [6%] vs ten [2%]), decreased lymphocyte count (29 [6%] vs nine [2%]), diarrhoea (18 [4%] vs 39 [9%]), and peripheral neuropathy (six [1%] vs 28 [6%]). Treatment-related deaths occurred in five (1%) of 463 patients in the carfilzomib group (pneumonia [n=2], interstitial lung disease [n=1], septic shock [n=1], and unknown [n=1]) and two (<1%) of 456 patients in the bortezomib group (cardiac arrest [n=1] and pneumonia [n=1]). INTERPRETATION: Carfilzomib provided a significant and clinically meaningful reduction in the risk of death compared with bortezomib. To our knowledge, carfilzomib is the first and only multiple myeloma treatment that extends overall survival in the relapsed setting over the current standard of care. This study is informative for deciding which proteasome inhibitor to use for treating this disease. FUNDING: Onyx Pharmaceuticals Inc, an Amgen Inc subsidiary.