Search

The ability to image cell chemistry at the nanoscale is key for understanding cell biology, but many optical microscopies are restricted by the ~250nm diffraction limit. Electron microscopy and super-resolution fluorescence techniques beat this limit, but rely on staining and specialised labelling to generate image contrast. It is challenging, therefore, to obtain information about the functional chemistry of intracellular components. Here we demonstrate a technique for intracellular label-free chemical mapping with nanoscale (~30nm) resolution. We use a probe-based optical microscope illuminated with a mid-infrared laser whose wavelengths excite vibrational modes of functional groups occurring within biological molecules. As a demonstration, we chemically map intracellular structures in human multiple myeloma cells and compare the morphologies with electron micrographs of the same cell line. We also demonstrate quantitative and label-free mapping at multiple wavelengths chosen to target the chemical signatures of macromolecules, including proteins and nucleic acids, in a way that can be used to identify biochemical markers in the study of disease and pharmacology.

Understanding the biological and clinical impact of copy number aberrations (CNAs) on the development of precision therapies in cancer remains an unmet challenge. Genetic amplification of chromosome 1q (chr1q-amp) is a major CNA conferring an adverse prognosis in several types of cancer, including in the blood cancer multiple myeloma (MM). Although several genes across chromosome 1 (chr1q) portend high-risk MM disease, the underpinning molecular etiology remains elusive. Here, with reference to the 3-dimensional (3D) chromatin structure, we integrate multi-omics data sets from patients with MM with genetic variables to obtain an associated clinical risk map across chr1q and to identify 103 adverse prognosis genes in chr1q-amp MM. Prominent among these genes, the transcription factor PBX1 is ectopically expressed by genetic amplification and epigenetic activation of its own preserved 3D regulatory domain. By binding to reprogrammed superenhancers, PBX1 directly regulates critical oncogenic pathways and a FOXM1-dependent transcriptional program. Together, PBX1 and FOXM1 activate a proliferative gene signature that predicts adverse prognosis across multiple types of cancer. Notably, pharmacological disruption of the PBX1-FOXM1 axis with existing agents (thiostrepton) and a novel PBX1 small molecule inhibitor (T417) is selectively toxic against chr1q-amp myeloma and solid tumor cells. Overall, our systems medicine approach successfully identifies CNA-driven oncogenic circuitries, links them to clinical phenotypes, and proposes novel CNA-targeted therapy strategies in MM and other types of cancer.

Purpose Patients with multiple myeloma suffer from disease-related complications such as bone destruction, toxicities from repeated therapies and age-related co-morbidities. With improved treatment options, patients are living longer and have specific survivorship needs such as low exercise levels that need to be addressed. In this study, we designed, implemented and evaluated a multidisciplinary team (MDT) myeloma clinic that provided participants with tailored exercise and lifestyle advice. Methods The Promoting Individualised Self-Management and Survivorship (PrISMS) clinic was set up in two UK myeloma centres. This remote MDT clinic comprised of a doctor, a nurse specialist and a physiotherapist. Patients were required to complete blood tests and a questionnaire about their symptoms and concerns before each consultation. Patient-reported outcome measures were captured using validated questionnaires. Patient feedback was collected using a specially designed survey and structured telephone interviews. Results Sixty-one patients were enrolled in the pilot clinic with 210 consultations held during the study period. Nine patients had disease progression and were referred safely back to face-to-face clinics. There was a significant improvement in patients’ exercise score (p = 0.02) after PrISMS clinic. Patient satisfaction was high, with 83% feeling more confident in self-managing myeloma after PrISMS clinic. Conclusion PrISMS clinic is safe and feasible, with high patient compliant and acceptability. It empowers patients to self-manage their condition and encourages physical activity, which is associated with improved quality of life and fatigue level. Future randomised controlled trials will help to confirm its benefits on patient clinical outcomes and cost-effectiveness.

Peer reviewed: True, INTRODUCTION: Multiple myeloma is a plasma cell malignancy that accounts for 1%-2% of newly diagnosed cancers.At diagnosis, approximately 20% of patients can be identified, using cytogenetics, to have inferior survival (high-risk). Additionally, standard-risk patients, with detectable disease (minimal residual disease (MRD)-positive) postautologus stem cell transplant (ASCT), fare worse compared with those who do not (MRD-negative). Research is required to determine whether a risk-adapted approach post-ASCT could further improve patient outcomes. METHODS: RADAR is a UK, multicentre, risk-adapted, response-guided, open-label, randomised controlled trial for transplant-eligible newly diagnosed multiple myeloma patients, using combinations of lenalidomide (R), cyclophosphamide (Cy), bortezomib (Bor), dexamethasone (D) and isatuximab (Isa).Participants receive RCyBorD(x4) induction therapy, followed by high-dose melphalan and ASCT. Post-ASCT, there are three pathways as follows:A phase III discontinuation design to assess de-escalating therapy in standard-risk MRD-negative patients. Participants receive 12 cycles of Isa maintenance. Those who remain MRD-negative are randomised to either continue or stop treatment.A phase II/III multiarm multistage design to test treatment strategies for treatment escalation in standard-risk MRD-positive patients. Participants are randomised to either; R, RBorD(x4) +R, RIsa, or RBorIsaD(x4) + RIsa.A phase II design to assess the activity of intensive treatment strategies in high-risk patients. Participants are randomised to RBorD(x4) +R or RBorIsaD(x4) + RIsa.1400 participants will be registered to allow for 500, 450 and 172 participants in each pathway. Randomisations are equal and treatment is given until disease progression or intolerance. ETHICS AND DISSEMINATION: Ethical approval was granted by the London-Central Research Ethics Committee (20/LO/0238) and capacity and capability confirmed by the appropriate local research and development department for each participating centre prior to opening recruitment. Participant informed consent is required before trial registration and reconfirmed post-ASCT. Results will be disseminated by conference presentations and peer-reviewed publications. TRIAL REGISTRATION NUMBER: ISCRTN46841867.

IntroductionMultiple myeloma is a malignancy of plasma cells with around 6000 new cases per year in the UK. Cyclophosphamide plus prednisolone is considered a standard of care for disease and symptom control in the advanced relapsed or refractory myeloma setting within the UK NHS. The selective nuclear export inhibitor, selinexor, has been relatively well tolerated in previous clinical trials and offers promise when used in combination with a wide range of other anti-cancer treatments. Here, we investigate if the addition of selinexor can improve responses to cyclophosphamide plus prednisolone without adding prohibitive toxicity.Methods and analysisMUKtwelve is a UK-based, randomised, controlled, open, parallel group, multicentre phase II trial designed to evaluate clinical efficacy of selinexor in combination with cyclophosphamide and prednisolone (SCP) in patients with relapsed or refractory multiple myeloma. A calibration arm will receive cyclophosphamide and prednisolone alone (CP). Participants who experience disease progression on the CP arm may, if eligible, receive SCP.The MUKtwelvetrial results will be the first to assess clinical efficacy of selinexor with low-dose CP in relapsed/refractory multiple myeloma. It is widely accepted that the relapsing-remitting nature of the disease is accompanied by cellular changes that often result in the requirement for novel agents and drug combinations to regain disease control. Patients also often experience cumulative toxicities throughout their treatments, limiting the treatment intensity that can be given at relapse. Thus, there is a need for novel effective combination therapies with acceptable toxicity profiles.Ethics and disseminationEthics approval is obtained. Results will be submitted for publication in a peer-reviewed journal.Trial registration numberISRCTN15028850.

Objective: To assess the test–retest reproducibility and intra/interobserver agreement of apparent diffusion coefficient (ADC) measurements of myeloma lesions using whole body diffusion-weighted MRI (WB-DW-MRI) at 3T MRI. Methods: Following ethical approval, 11 consenting patients with relapsed multiple myeloma were prospectively recruited and underwent baseline WB-DW-MRI. For a single bed position, axial DWI was repeated after a short interval to permit test–retest measurements. Mean ADC measurement was performed by two experienced observers. Intra- and interobserver agreement and test–retest reproducibility were assessed, using coefficient of variation (CV) and interclass correlation coefficient (ICC) measures, for diffuse and focal lesions (small ≤10 mm and large >10 mm). Results: 47 sites of disease were outlined (23 focal, 24 diffuse) in different bed positions (pelvis = 22, thorax = 20, head and neck = 5). For all lesions, there was excellent intraobserver agreement with ICC of 0.99 (0.98–0.99) and COV of 5%. For interobserver agreement, ICC was 0.89 (0.8–0.934) and COV was 17%. There was poor interobserver agreement for diffuse disease (ICC = 0.46) and small lesions (ICC = 0.54). For test–retest reproducibility, excellent ICC (0.916) and COV (14.5%) values for mean ADC measurements were observed. ICCs of test–retest were similar between focal lesions (0.83) and diffuse infiltration (0.80), while ICCs were higher in pelvic (0.95) compared to thoracic (0.81) region and in small (0.96) compared to large (0.8) lesions. Conclusion: ADC measurements of focal lesions in multiple myeloma are repeatable and reproducible, while there is more variation in ADC measurements of diffuse disease in patients with multiple myeloma. Advances in knowledge: Mean ADC measurements are repeatable and reproducible in focal lesions in multiple myeloma, while the ADC measurements of diffuse disease in multiple myeloma are more subject to variation. The evidence supports the future potential role of ADC measurements as predictive quantitative biomarker in multiple myeloma.

The all-oral combination of ixazomib, cyclophosphamide, and dexamethasone (ICD) is well tolerated and effective in newly diagnosed and relapsed multiple myeloma (MM). We carried out MUKeight, a randomised, controlled, open, parallel group, multi-centre phase II trial in patients with relapsed MM after prior treatment with thalidomide, lenalidomide, and a proteasome inhibitor (ISRCTN58227268), with the primary objective to test whether ICD has improved clinical activity compared to cyclophosphamide and dexamethasone (CD) in terms of progression-free survival (PFS). Between January 2016 and December 2018, 112 participants were randomised between ICD (n = 58) and CD (n = 54) in 33 UK centres. Patients had a median age of 70 years and had received a median of four prior lines of therapy. 74% were classed as frail. Median PFS in the ICD arm was 5.6 months, compared to 6.7 months with CD (hazard ratio (HR) = 1.21, 80% CI 0.9–1.6, p = 0.3634). Response rates and overall survival were not significantly different between ICD and CD. Dose modifications or omissions, and serious adverse events (SAEs), occurred more often in the ICD arm. In summary, the addition of ixazomib to cyclophosphamide and dexamethasone did not improve outcomes in the comparatively frail patients enroled in the MUKeight trial.

Multiple Myeloma (MM) often presents with unspecific symptoms and is challenging to diagnose. We performed this DSMM/EMN-analysis via test-(retro-) and validation (prospective) study to determine the time interval from the onset of first symptoms to the diagnosis of MM. The retrospective and prospective analyses were performed in 101 and 176 patients, respectively. The median time from first symptoms to the MM diagnosis in both cohorts was 4 and 6 months, respectively. Frequencies of MM-related pathologic bone fractures, renal and infectious complications at diagnosis occurred in 41%, 35% and 16% of patients, respectively. Our MM-questionnaire determined that 39% of patients were dissatisfied with the diagnostic process. PFS and OS proved insignificantly different with shorter (≤6) and longer (>6 months) latency periods. In conclusion, our in depth studies demonstrate that delays in diagnosis do not decrease PFS or OS, but induce MM-related complications and influence patients' satisfaction with their medical care.

Understanding the biological and clinical impact of copy number aberrations (CNA) in cancer remains an unmet challenge. Genetic amplification of chromosome 1q (chr1q-amp) is a major CNA conferring adverse prognosis in several cancers, including the blood cancer, multiple myeloma (MM). Although several chr1q genes portend high-risk MM disease, the underpinning molecular aetiology remains elusive. Here we integrate patient multi-omics datasets with genetic variables to identify 103 adverse prognosis genes in chr1q-amp MM. Amongst these, the transcription factor PBX1 is ectopically expressed by genetic amplification and epigenetic activation of its own preserved 3D regulatory domain. By binding to reprogrammed super-enhancers, PBX1 directly regulates critical oncogenic pathways, whilst in co-operation with FOXM1, activates a proliferative gene signature which predicts adverse prognosis across multiple cancers. Notably, pharmacological disruption of the PBX1-FOXM1 axis, including with a novel PBX1 inhibitor is selectively toxic against chr1q-amp cancer cells. Overall, our systems medicine approach successfully identifies CNA-driven oncogenic circuitries, links them to clinical phenotypes and proposes novel CNA-targeted therapy strategies in cancer.SignificanceWe provide a comprehensive systems medicine strategy to unveil oncogenic circuitries and inform novel precision therapy decisions against CNA in cancer. This first clinical multi-omic analysis of chr1q-amp in MM identifies a central PBX1-FOXM1 regulatory axis driving high-risk prognosis, as a novel therapeutic target against chr1q-amp in cancer.

Multiple myeloma is a genetically heterogeneous cancer of the bone marrow plasma cells (PC). Distinct myeloma transcriptome profiles are primarily driven by myeloma initiating events (MIE) and converge into a mutually exclusive overexpression of the CCND1 and CCND2 oncogenes. Here, with reference to their normal counterparts, we find that myeloma PC enhanced chromatin accessibility combined with paired transcriptome profiling can classify MIE-defined genetic subgroups. Across and within different MM genetic subgroups, we ascribe regulation of genes and pathways critical for myeloma biology to unique or shared, developmentally activated or de novo formed candidate enhancers. Such enhancers co-opt recruitment of existing transcription factors, which although not transcriptionally deregulated per se, organise aberrant gene regulatory networks that help identify myeloma cell dependencies with prognostic impact. Finally, we identify and validate the critical super-enhancer that regulates ectopic expression of CCND2 in a subset of patients with MM and in chronic lymphocytic leukemia., Despite extensive genetic heterogeneity, nearly half of all multiple myeloma (MM) cases are driven by cyclin D2 (CCND2) over-expression. Here the authors dissect the chromatin landscape of MM to provide insights into the transcriptional regulatory landscape driving MM and divergent transcriptomes corresponding to different MM genetic subtypes.

Introduction: The BOSTON study is a Phase 3 trial comparing the novel triplet regimen of once weekly oral selinexor with once weekly bortezomib and dexamethasone (SVd) versus standard twice weekly Vd in patients with multiple myeloma (MM) after 1-3 prior therapies. The SVd regimen conferred a 47% increase in median progression-free survival (PFS) and time to next therapy (TTNT), higher overall response rates (ORR) and deeper responses compared to Vd. Furthermore, this is the first trial of a bortezomib-based triplet therapy (i.e., SVd) that showed lower rates of overall and Grade ≥2 peripheral neuropathy (PN) compared with doublet Vd while conferring a longer PFS, and the regimen requires ~35% fewer clinic visits than standard twice weekly Vd. This abstract reports analyses of the patient reported outcomes (PROs) in BOSTON to evaluate patterns in therapy-induced PN symptoms, pain and function. Methods: PROs were assessed at baseline and day 1 of each cycle using the European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30 and EORTC QLQ-CIPN20 questionnaires. The QLQ-CIPN20 assesses patients' experience of symptoms and functional limitations related to chemotherapy induced PN (CIPN) and has 3 subscales: sensory, motor, and autonomic. The QLQ-C30 includes several functional and symptom scales and focuses on physical functioning, role functioning, and pain subscales as pre-specified domains of interest. Mixed effects repeated measures models were fit to the longitudinal data to estimate differences over time. Meaningful change thresholds derived using anchor- and distribution-based methods or estimated from the literature were used to identify patients who had experienced a meaningful worsening of symptoms or deterioration in functioning. Time to definitive deterioration was defined as the time from randomization to the first occurrence of meaningful deterioration that was not followed by subsequent improvement. Cox proportional hazard models compared the hazard rates between arms adjusted for baseline questionnaire score, randomization stratification factors (prior PI therapy, number of prior anti-MM regimens, R-ISS stage at MM) and prior bortezomib exposure. Results: A total of 402 patients were enrolled in the trial; 388 completed a baseline QLQ-CIPN20 assessment and are included in these analyses. Based on the mixed model repeated measures analysis (Table 1), a benefit was demonstrated for SVd in change from baseline to Day 106 for sensory (-5.3 points difference, p=0.0006) and pain (-6.6, p=0.007) scores. Patients in the SVd arm had a greater increase in autonomic symptom scores (+5.0, p=0.022). The number of patients with definitive deterioration in QLQ-CIPN20 sensory symptoms was greater in the Vd arm (86 patients, 45.7%) compared to 52 (27.7%) patients in the SVd arm (Table 2). The median time to deterioration was 20.7 months (95% confidence interval [CI]: 15.4, not estimable [NE]) in the SVd arm compared to 12.5 months (95% CI: 7.8, 19.9) in the Vd arm. The adjusted hazard ratio (HR) comparing time to deterioration in sensory scores between SVd and Vd arms was 0.53 (95% CI: 0.38, 0.75; p = 0.0004). Worsening of motor symptoms also trended in favor of SVd with a HR = 0.72 (p=0.052). Roughly half of the patients in each treatment arm experienced worsening autonomic symptoms (54.6% and 48.4%, SVd and Vd respectively) with no significant difference between arms (HR=1.14, p=0.37). While not statistically significant, fewer SVd patients had definitive deteriorations in pain and physical function compared to Vd patients, with similar or extended time to deterioration (Table 2). Conclusions: In the setting of a significant increase in PFS and TTNT, patients with MM after at least one prior therapy who received weekly SVd reported lower sensory symptom and pain scores but higher autonomic symptom scores. Further, patients treated with twice weekly Vd experienced a more rapid rate of sensory symptom worsening and a trend to more rapid worsening of motor symptoms, compared to patients treated with SVd. The improved pain scores in patients treated with SVd may be related to superior disease control. The reduction in PN-related pain and sensory symptoms observed with SVd in the setting of increased PFS and TTNT supports a potentially improved patient experience and decreased health care burden and long term morbidity. Disclosures Leleu: Janssen: Honoraria; BMS-celgene: Honoraria; Novartis: Honoraria; Amgen: Honoraria; GSK: Honoraria; Sanofi: Honoraria; Karyopharm: Honoraria; Oncopeptide: Honoraria; AbbVie: Honoraria; Carsgen: Honoraria; Incyte: Honoraria; Merck: Honoraria. Beaumont:Clinical Outcomes Solutions: Current Employment; Karyopharm Therapeutics: Consultancy. Yu:Clinical Outcomes Solutions: Current Employment; Karyopharm Therapeutics: Consultancy. Hudgens:Clinical Outcomes Solutions: Current Employment; Sierra Oncology: Consultancy; Karyopharm Therapeutics: Consultancy. Auner:Karyopharm: Consultancy, Honoraria; Amgen: Consultancy, Honoraria, Research Funding; Takeda: Consultancy, Honoraria. Quach:Sanofi: Consultancy, Research Funding; GlaxoSmithKline: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Research Funding; Glaxo Kline Smith: Consultancy, Research Funding; Karyopharm: Consultancy, Honoraria, Research Funding; Janssen Cilag: Consultancy, Honoraria. Delimpasi:Amgen: Honoraria; Takeda: Honoraria; Janssen: Honoraria; GENESIS: Honoraria. Spicka:Celgene, Amgen, Janssen-Cilag, Takeda, Bristol-Myers Squibb, Novartis, Sanofi: Consultancy, Honoraria, Speakers Bureau. Dimopoulos:Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees, Speakers Bureau; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees, Research Funding, Speakers Bureau; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees, Research Funding, Speakers Bureau; BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees, Research Funding, Speakers Bureau. Hajek:Celgene: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Research Funding; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Abbvie: Consultancy, Honoraria; PharmaMar: Consultancy, Honoraria; Oncopeptides: Consultancy. Venner:Celgene, Amgen: Research Funding; Janssen, BMS/Celgene, Sanofi, Takeda, Amgen: Honoraria. Garg:Janssen, Takeda, Celgene, Novartis, Sanofi: Honoraria. Stevens:Amgen, MorphoSys: Consultancy. Jagannath:BMS, Janssen, Karyopharm, Legend Biotech, Sanofi, Takeda: Consultancy. Moreau:Janssen: Consultancy, Honoraria; Celgene/Bristol-Myers Squibb: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Sanofi: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; Novartis: Honoraria; Takeda: Honoraria. Levy:Karyopharm,Takeda, BMS: Consultancy, Honoraria, Speakers Bureau. Bahlis:BMS/Celgene and Janssen: Consultancy, Honoraria, Other: Travel, Accomodations, Research Funding; AbbVie: Consultancy, Honoraria; Genentech: Consultancy, Honoraria; GSK: Consultancy, Honoraria; Karyopharm Therapeutics: Consultancy, Honoraria; Sanofi: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Amgen: Consultancy, Honoraria. Facon:Celgene, Janssen, Takeda, Amgen, Roche, Karyopharm, Oncopeptides, BMS, Sanofi: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Chai:Karyopharm Therapeutics Inc: Current Employment. Ma:Karyopharm: Current Employment, Current equity holder in private company. Tang:Karyopharm Therapeutics: Current Employment. Leong:AbbVie: Ended employment in the past 24 months; Karyopharm Therapeutics: Current Employment. Shah:Karyopharm: Current Employment, Current equity holder in publicly-traded company. Shacham:Karyopharm: Current Employment, Current equity holder in publicly-traded company, Patents & Royalties: (8999996, 9079865, 9714226, PCT/US12/048319, and I574957) on hydrazide containing nuclear transport modulators and uses, and pending patents PCT/US12/048319, 499/2012, PI20102724, and 2012000928) . Kauffman:Karyopharm Therapeutics Inc: Current Employment, Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees. Richardson:Celgene/BMS, Oncopeptides, Takeda, Karyopharm: Research Funding.

Introduction Selinexor is a first-in-class, oral, potent selective inhibitor of nuclear export (SINE) which blocks XPO1, forcing the nuclear retention and activation of tumor suppressor proteins, leading to cancer cell apoptosis. Selinexor has demonstrated antimyeloma activity in triple class refractory multiple myeloma (MM) [Chari et al. NEJM 2019]. Selinexor synergizes with proteasome inhibitors (PIs) in PI-sensitive and -resistant cell lines and produces high response rates in patients with PI refractory and non-refractory MM (Bahlis et al. Blood 2018). In the phase 3 BOSTON study, the combination of once weekly (QW) selinexor, QW bortezomib, and dexamethasone (SVd) in patients who had received 1-3 prior therapies led to a significantly longer (47%) median progression-free survival (PFS) of 13.93 vs 9.46 months, with a hazard ratio of 0.70 (P=0.0075) compared to standard twice weekly bortezomib and dexamethasone (Vd). In addition, SVd regimen produced higher response rates and deeper responses (ORR: 76.4% vs 62.3% and ≥CR 16.9% vs 10.2%) compared with Vd. The benefit with SVd was observed across all efficacy endpoints and was associated with lower incidence and severity of bortezomib-induced peripheral neuropathy. Here we analyzed the effect of prior PI therapy (bortezomib, carfilzomib, ixazomib) on the efficacy and safety of SVd compared with Vd. Methods BOSTON is an open-label, randomized phase 3 study in patients with MM comparing SVd (QW oral selinexor 100 mg, QW subcutaneous bortezomib 1.3 mg/m2, and BIW oral dexamethasone 20 mg), versus Vd (BIW bortezomib 1.3 mg/m2 and QIW dexamethasone 20 mg). Patients previously treated with a PI must have had at least a partial response (PR) to the PI and 6 months since the last PI regimen. The study primary end point was PFS. Here we report subgroup analysis of treatment outcomes based on prior PI treatment. Results Subgroups consisted of PI naïve patients (n=95; 24%) and patients with prior PI treatment (n=307; 76%). Both the subgroups and study arms were comparable for baseline patient demographic and disease characteristics. However, those with prior PI treatment more frequently had a previous stem cell transplant (38% vs 24%) or 3 lines of prior anti MM therapy (21% vs 13%). Median PFS was improved with SVd compared with Vd in both the PI naïve group (PFS not reached (NR) vs 9.7 months; HR 0.2585 [95% CI, 0.1116-0.5988]; P=0.0003) and in the PI treated group (11.7 vs 9.4 months; HR 0.7839 [95% CI, 0.5791-1.0612]; P=0.06). Other efficacy endpoints are shown in the table. Peripheral neuropathy ≥grade 2 (a secondary study endpoint) was less frequent in the SVd compared with the Vd arm (PI naïve: 25.5%, Vd 43.8%, P=0.0302; PI treated: SVd 19.6%, Vd 31.4%, P=0.0092). Adverse events of ≥grade 3 occurred in 71% of patients in the PI naïve group (SVd 77%, Vd 65%) and 74% of patients in the PI treated group (SVd 88%, Vd 60%). Thrombocytopenia was more frequent in patients in the SVd arms (PI naïve: SVd 32%, Vd 13%; PI treated: SVd 42%, Vd 19%) as was anemia (PI naïve: SVd 15%, Vd 6%; PI treated: SVd 16%, Vd 12%), and fatigue (PI naïve: SVd 15%, Vd 2%; PI treated: SVd 13%, Vd 1%). Conclusions The once-weekly SVd combination was associated with significant clinical benefit and reduced peripheral neuropathy as compared with standard twice-weekly Vd in patients with MM and 1-3 prior therapies, regardless of prior therapy with a PI. However, the benefits of SVd over Vd were more pronounced in patients who had never been treated with a PI (PFS HR 0.26), suggesting that selinexor could be an optimal partner for combining with weekly bortezomib as the first PI-containing MM regimen. Figure 1 Disclosures Mateos: Roche: Honoraria; Seattle Genetics: Honoraria; EDO Mundipharma: Honoraria; Adaptive Biotechnologies: Honoraria; GlaxoSmithKline: Honoraria; Abbvie: Honoraria; Takeda: Honoraria; Amgen: Honoraria; Bristol-Myers Squibb: Honoraria; Janssen: Honoraria. Gavriatopoulou:Amgen: Consultancy, Honoraria; Karyopharm: Consultancy, Honoraria; Genesis Pharma: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Takeda: Consultancy, Honoraria. Facon:Celgene, Janssen, Takeda, Amgen, Roche, Karyopharm, Oncopeptides, BMS, Sanofi: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Auner:Karyopharm: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Amgen: Consultancy, Honoraria, Research Funding. Leleu:AbbVie: Honoraria; GSK: Honoraria; Amgen: Honoraria; Novartis: Honoraria; Carsgen: Honoraria; Incyte: Honoraria; Merck: Honoraria; BMS-celgene: Honoraria; Janssen: Honoraria; Oncopeptide: Honoraria; Sanofi: Honoraria; Karyopharm: Honoraria. Hajek:Novartis: Consultancy, Honoraria, Research Funding; Roche: Consultancy, Honoraria, Research Funding; Oncopeptides: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharma MAR: Consultancy, Honoraria; BMS: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Dimopoulos:Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees, Research Funding, Speakers Bureau; BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees, Research Funding, Speakers Bureau; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees, Speakers Bureau; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees, Research Funding, Speakers Bureau. Delimpasi:GENESIS: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Amgen: Consultancy, Honoraria. Spicka:Celgene, Amgen, Janssen-Cilag, Takeda, Bristol-Myers Squibb, Novartis, Sanofi: Consultancy, Honoraria, Speakers Bureau. Kryachok:Janssen, Bayer, Karyopharm, MSD, Acerta, AvbbVie, Debiopharm: Research Funding; Takeda, Janssen: Consultancy; Takeda, MSD, AbbVie, Ro: Other: Travel, accommodations, expenses; Takeda, Janssen, Novartis, Roche, MSD, Bayer: Consultancy, Research Funding. Sinha:Dr Reddys Lab, Intas Pharmaceuticals, Karyopharm Therapeutics: Honoraria. Venner:Celgene, Amgen: Research Funding; Janssen, BMS/Celgene, Sanofi, Takeda, Amgen: Honoraria. Garg:Janssen, Takeda, Celgene, Novartis, Sanofi: Honoraria. Stevens:Amgen, MorphoSys: Consultancy. Quach:GlaxoSmithKline: Consultancy, Honoraria, Research Funding; Sanofi: Consultancy, Research Funding; Glaxo Kline Smith: Consultancy, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Research Funding; Janssen Cilag: Consultancy, Honoraria; Karyopharm: Consultancy, Honoraria, Research Funding. Jagannath:BMS, Janssen, Karyopharm, Legend Biotech, Sanofi, Takeda: Consultancy. Moreau:Amgen: Consultancy, Honoraria; Sanofi: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; Takeda: Honoraria; Janssen: Consultancy, Honoraria; Celgene/Bristol-Myers Squibb: Consultancy, Honoraria; Novartis: Honoraria. Levy:Karyopharm,Takeda, BMS: Consultancy, Honoraria, Speakers Bureau. Badros:Amgen: Consultancy; University of Maryland: Current Employment. Anderson:Karyopharm: Consultancy, Honoraria, Research Funding; BMS: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Research Funding; GSK: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding. Bahlis:Sanofi: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; BMS/Celgene and Janssen: Consultancy, Honoraria, Other: Travel, Accomodations, Research Funding; AbbVie: Consultancy, Honoraria; Genentech: Consultancy, Honoraria; Karyopharm Therapeutics: Consultancy, Honoraria; GSK: Consultancy, Honoraria. Cavo:Jannsen, BMS, Celgene, Sanofi, GlaxoSmithKline, Takeda, Amgen, Oncopeptides, AbbVie, Karyopharm, Adaptive: Consultancy, Honoraria. Chai:Karyopharm Therapeutics Inc: Current Employment. Arazy:Karyopharm Therapeutics Inc.: Current Employment. Shah:Karyopharm Therapeutics Inc: Current Employment, Current equity holder in publicly-traded company. Shacham:Karyopharm: Current Employment, Current equity holder in publicly-traded company, Patents & Royalties: (8999996, 9079865, 9714226, PCT/US12/048319, and I574957) on hydrazide containing nuclear transport modulators and uses, and pending patents PCT/US12/048319, 499/2012, PI20102724, and 2012000928) . Kauffman:Karyopharm Therapeutics Inc: Current Employment, Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees. Richardson:Celgene/BMS, Oncopeptides, Takeda, Karyopharm: Research Funding.

Introduction Selinexor is a first-in-class, oral, potent selective inhibitor of nuclear export (SINE) which blocks XPO1, forcing the nuclear retention and activation of tumor suppressor proteins, leading to cancer cell apoptosis. Selinexor has demonstrated antimyeloma activity in triple class refractory multiple myeloma (MM) [Chari et al. NEJM 2019]. Selinexor synergizes with proteasome inhibitors (PIs) in PI-sensitive and -resistant cell lines and produces high response rates in patients with PI refractory and non-refractory MM. (Bahlis et al. Blood 2018). In the phase 3 BOSTON study, the combination of once weekly (QW) selinexor, QW bortezomib and dexamethasone (SVd) in patients who had received 1-3 prior therapies led to a significantly (47%) longer median progression-free survival (PFS) of 13.93 versus 9.46 months (HR 0.70; P=0.0075) compared to standard twice weekly bortezomib and dexamethasone (Vd). In addition, SVd regimen produced higher response rates and deeper responses (ORR: 76.4% vs 62.3% and ≥CR 16.9% vs 10.2%) compared with Vd. The benefit with SVd was observed across all efficacy endpoints and was associated with lower incidence and severity of bortezomib-induced peripheral neuropathy. Here we present subgroup analyses according to number of prior lines of therapy and prior treatment with lenalidomide (LEN). Methods BOSTON is an open-label, randomized phase 3 study in patients with MM comparing SVd (QW selinexor 100 mg, QW subcutaneous bortezomib 1.3 mg/m2, and 20 mg twice weekly [BIW] dexamethasone), versus Vd (1.3 mg/m2 bortezomib BIW and dexamethasone 20 mg 4 x weekly [QIW]). Patients previously treated with a PI must have had at least a partial response (PR) to the PI and 6 months since the last PI regimen. The study primary end point was PFS. Results Of the 402 patients in the BOSTON study, 198 (49%) had 1 prior line versus 204 (51%) with 2-3 prior lines. In addition, 154 (38%) comprised the LEN treated subgroup, versus 248 (62%) in the LEN naïve subgroup. Of note, 41% patients received prior thalidomide, which is consistent with most of the BOSTON study patients being treated in the EU. Baseline demographic and disease characteristics were well balanced between treatment arms across subgroups. A very good partial response (VGPR) or better to most recent prior line anti-MM therapy was more frequent in patients with 1 prior line of therapy (63% vs 41%) versus those with 2-3 prior lines of therapy. Patients with prior LEN therapy were more likely to have had 2-3 prior therapies (72.1%) compared with LEN naive patients (37.5%). As shown in the table, SVd was associated with longer PFS compared with Vd in all subgroups. Overall response rates (ORR) and times-to-next-treatment (TTNT) were statistically greater with SVd compared with Vd in all subgroups. Rates of very good partial response or better (VGPR) were statistically greater for SVd vs Vd in the LEN-naïve group and 1 prior treatment group. Grade ≥2 peripheral neuropathy (a key secondary endpoint prespecified in the study) occurred less frequently across all SVd subgroups compared with Vd: LEN treated (21% SVd, 37% Vd, P=0.0166); LEN-naïve (21% SVd, 33% Vd, P=0.0252), 1 prior line (21% SVd, 33% Vd, P=0.0501); 2-3 prior lines (21% SVd, 36% Vd, P=0.0107). Adverse events of ≥grade 3 were more commonly reported in the SVd treatment arm than in the Vd arm, LEN treated (83% SVd, 57% Vd), LEN-naïve (76% SVd, 55% Vd), 1 prior line (77% SVd, 56% Vd), 2-3 prior lines (81% SVd, 56% Vd), and were mostly managed with dose modification and/or supportive treatment. Pneumonia occurred at comparable rates between treatment arms. There were no differences between subgroups in grade 3 adverse events. Conclusions In the BOSTON study, once-weekly SVd significantly improved PFS, ORR, TTNT and reduced rates of ≥grade 2 peripheral neuropathy compared with Vd regardless of number of prior treatments or whether patients were previously treated with LEN. Adverse events were managed with dose modification and treatment-related discontinuation rates did not differ between the 2 regimens for any subgroup. The PFS of 16.6 months with SVd after 1 prior therapy, and the HR of 0.63 in patients with prior LEN treatment support the use of once-weekly SVd for the second line treatment of MM following a LEN-containing regimen. Table Disclosures Mateos: Takeda: Honoraria; Abbvie: Honoraria; GlaxoSmithKline: Honoraria; EDO Mundipharma: Honoraria; Seattle Genetics: Honoraria; Roche: Honoraria; Bristol-Myers Squibb: Honoraria; Janssen: Honoraria; Amgen: Honoraria; Adaptive Biotechnologies: Honoraria. Jagannath:Takeda: Consultancy, Honoraria; Sanofi: Consultancy, Honoraria; BMS: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Karyopharm: Consultancy, Honoraria; Legend Biotech: Consultancy, Honoraria. Delimpasi:GENESIS: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Amgen: Consultancy, Honoraria. Spicka:Celgene, Amgen, Janssen-Cilag, Takeda, Bristol-Myers Squibb, Novartis, Sanofi: Consultancy, Honoraria, Speakers Bureau. Kryachok:Takeda, Janssen, Novartis, Roche, MSD, Bayer: Consultancy, Research Funding; Janssen, Bayer, Karyopharm, MSD, Acerta, AvbbVie, Debiopharm: Research Funding; Takeda, MSD, AbbVie, Ro: Other: Travel, accommodations, expenses; Takeda, Janssen: Consultancy. Gavriatopoulou:Amgen: Consultancy, Honoraria; Karyopharm: Consultancy, Honoraria; Genesis Pharma: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Takeda: Consultancy, Honoraria. Dimopoulos:Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees, Research Funding, Speakers Bureau; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees, Research Funding, Speakers Bureau; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees, Speakers Bureau; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees, Research Funding, Speakers Bureau; BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees. Auner:Amgen: Consultancy, Honoraria, Research Funding; Karyopharm: Consultancy, Honoraria; Takeda: Consultancy, Honoraria. Leleu:BMS-celgene: Honoraria; Carsgen: Honoraria; Incyte: Honoraria; Merck: Honoraria; AbbVie: Honoraria; Oncopeptide: Honoraria; Janssen: Honoraria; Novartis: Honoraria; Amgen: Honoraria; GSK: Honoraria; Sanofi: Honoraria; Karyopharm: Honoraria. Sinha:Dr Reddys Lab, Intas Pharmaceuticals, Karyopharm Therapeutics: Honoraria. Venner:Celgene, Amgen: Research Funding; Janssen, BMS/Celgene, Sanofi, Takeda, Amgen: Honoraria. Garg:Janssen, Takeda, Celgene, Novartis, Sanofi: Honoraria. Stevens:Amgen, MorphoSys: Consultancy. Quach:Amgen, Celgene, karyopharm, GSK, Janssen Cilag, Sanofi.: Membership on an entity's Board of Directors or advisory committees; GlaxoSmithKline, Karyopharm, Amgen, Celgene, Janssen Cilag: Honoraria; GlaxoSmithKline, Karyopharm, Amgen, Celgene, Janssen Cilag: Consultancy; Amgen, sanofi, celgene, Karyopharm, GSK: Research Funding. Moreau:Novartis: Honoraria; Amgen: Consultancy, Honoraria; Celgene/Bristol-Myers Squibb: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Takeda: Honoraria; Sanofi: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria. Levy:Sanofi: Consultancy, Honoraria, Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Karyopharm: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Bristol Meyers Squibb: Consultancy, Honoraria, Research Funding; AstraZeneca: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Research Funding; BeiGene: Consultancy, Research Funding, Speakers Bureau; Baylor University Med Center: Current Employment; Takeda: Consultancy, Honoraria, Research Funding. Badros:Amgen: Consultancy; University of Maryland: Current Employment. Anderson:Janssen: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Research Funding; GSK: Consultancy, Honoraria, Research Funding; BMS: Consultancy, Honoraria, Research Funding; Karyopharm: Consultancy, Honoraria, Research Funding. Bahlis:Genentech: Consultancy, Honoraria; Karyopharm Therapeutics: Consultancy, Honoraria; GSK: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria; BMS/Celgene and Janssen: Consultancy, Honoraria, Other: Travel, Accomodations, Research Funding; Sanofi: Consultancy, Honoraria. Facon:Celgene, Janssen, Takeda, Amgen, Roche, Karyopharm, Oncopeptides, BMS, Sanofi: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Cavo:Jannsen, BMS, Celgene, Sanofi, GlaxoSmithKline, Takeda, Amgen, Oncopeptides, AbbVie, Karyopharm, Adaptive: Consultancy, Honoraria. Chai:Karyopharm Therapeutics Inc: Current Employment. Arazy:Karyopharm Therapeutics Inc.: Current Employment. Shah:Karyopharm Therapeutics Inc: Current Employment, Current equity holder in publicly-traded company. Shacham:Karyopharm: Current Employment, Current equity holder in publicly-traded company, Patents & Royalties: (8999996, 9079865, 9714226, PCT/US12/048319, and I574957) on hydrazide containing nuclear transport modulators and uses, and pending patents PCT/US12/048319, 499/2012, PI20102724, and 2012000928) . Kauffman:Karyopharm Therapeutics Inc: Current Employment, Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees. Richardson:Celgene/BMS, Oncopeptides, Takeda, Karyopharm: Research Funding.

The proteasome inhibitors, carfilzomib and bortezomib, are widely used to treat myeloma but head-to-head comparisons have produced conflicting results. We compared the activity of these proteasome inhibitors in combination with cyclophosphamide and dexamethasone (KCd vs. VCd) in second-line treatment using fixed duration therapy and evaluated the efficacy of carfilzomib maintenance. MUKfive was a phase II controlled, parallel group trial that randomized patients (2:1) to KCd (n=201) or VCd (n=99); responding patients on carfilzomib were randomized to maintenance carfilzomib (n=69) or no further treatment (n=72). Primary endpoints were: (i) very good partial response (non-inferiority, odds ratio [OR] 0.8) at 24 weeks, and (ii) progression-free survival. More participants achieved a very good partial response or better with carfilzomib than with bortezomib (40.2% vs. 31.9%, OR=1.48, 90% confidence interval [CI]: 0.95, 2.31; non-inferior), with a trend for particular benefit in patients with adverse-risk disease. KCd was associated with higher overall response (partial response or better, 84.0% vs. 68.1%, OR=2.72, 90% CI: 1.62, 4.55, P=0.001). Neuropathy (grade ≥3 or ≥2 with pain) was more common with bortezomib (19.8% vs. 1.5%, P

Therapeutic regimens for previously treated multiple myeloma (MM) may not provide prolonged disease control and are often complicated by significant adverse events, including peripheral neuropathy. In patients with previously treated MM in the Phase 3 BOSTON study, once weekly selinexor, once weekly bortezomib, and 40 mg dexamethasone (XVd) demonstrated a significantly longer median progression-free survival (PFS), higher response rates, deeper responses, a trend to improved survival, and reduced incidence and severity of bortezomib-induced peripheral neuropathy when compared with standard twice weekly bortezomib and 80 mg dexamethasone (Vd). The pre-specified analyses described here evaluated the influence of the number of prior lines of therapy, prior treatment with lenalidomide, prior proteasome inhibitor (PI) therapy, prior immunomodulatory drug therapy, and prior autologous stem cell transplant (ASCT) on the efficacy and safety of XVd compared with Vd. In this 1:1 randomized study, enrolled patients were assigned to receive once weekly oral selinexor (100 mg) with once weekly subcutaneous bortezomib (1.3 mg/m2) and 40 mg per week dexamethasone (XVd) versus standard twice weekly bortezomib and 80 mg per week dexamethasone (Vd). XVd significantly improved PFS, overall response rate, time-to-next-treatment, and showed reduced all grade and grade ≥ 2 peripheral neuropathy compared with Vd regardless of prior treatments, but the benefits of XVd over Vd were more pronounced in patients treated earlier in their disease course who had either received only one prior therapy, had never been treated with a PI, or had prior ASCT. Treatment with XVd improved outcomes as compared to Vd regardless of prior therapies as well as manageable and generally reversible adverse events. XVd was associated with clinical benefit and reduced peripheral neuropathy compared to standard Vd in previously treated MM. These results suggest that the once weekly XVd regimen may be optimally administered to patients earlier in their course of disease, as their first bortezomib-containing regimen, and in those relapsing after ASCT.Trial registration: ClinicalTrials.gov (NCT03110562). Registered 12 April 2017. https://clinicaltrials.gov/ct2/show/NCT03110562.

Significance Cancer therapies often fail to cure patients because a proportion of tumor cells withstand the toxic effects of chemotherapy. How surviving cancer cells recover from sublethal drug-induced stress is not known, but given that cellular resources are finite, stress resolution may come at the expense of less essential systems. Here, we studied the global cellular events of stress buildup and resolution in the bone marrow cancer, multiple myeloma, after proteasome inhibition, a commonly used therapeutic approach. Using a temporal multiomics approach, we delineate the unexpectedly complex and protracted changes myeloma cells undergo during stress resolution and demonstrate that recovering cells are more vulnerable to specific insults than acutely stressed cells. Thus, the findings may provide avenues for optimizing cancer therapies., Cancer cells can survive chemotherapy-induced stress, but how they recover from it is not known. Using a temporal multiomics approach, we delineate the global mechanisms of proteotoxic stress resolution in multiple myeloma cells recovering from proteasome inhibition. Our observations define layered and protracted programs for stress resolution that encompass extensive changes across the transcriptome, proteome, and metabolome. Cellular recovery from proteasome inhibition involved protracted and dynamic changes of glucose and lipid metabolism and suppression of mitochondrial function. We demonstrate that recovering cells are more vulnerable to specific insults than acutely stressed cells and identify the general control nonderepressable 2 (GCN2)-driven cellular response to amino acid scarcity as a key recovery-associated vulnerability. Using a transcriptome analysis pipeline, we further show that GCN2 is also a stress-independent bona fide target in transcriptional signature-defined subsets of solid cancers that share molecular characteristics. Thus, identifying cellular trade-offs tied to the resolution of chemotherapy-induced stress in tumor cells may reveal new therapeutic targets and routes for cancer therapy optimization.

NA

Elderly and frail patients with multiple myeloma (MM) are more vulnerable to the toxicity of combination therapies, often resulting in treatment modifications and suboptimal outcomes. The phase 3 BOSTON study showed that once-weekly selinexor and bortezomib with low-dose dexamethasone (XVd) improved PFS and ORR compared with standard twice-weekly bortezomib and moderate-dose dexamethasone (Vd) in patients with previously treated MM. This is a retrospective subgroup analysis of the multicenter, prospective, randomized BOSTON trial. Post hoc analyses were performed to compare XVd versus Vd safety and efficacy according to age and frailty status (

Summary Osteoclast (OC) development in response to nuclear factor kappa-Β ligand (RANKL) is critical for bone homeostasis in health and in disease. The early and direct chromatin regulatory changes imparted by the BET chromatin readers Brd2-4 and OC-affiliated transcription factors (TFs) during osteoclastogenesis are not known. Here, we demonstrate that in response to RANKL, early OC development entails regulation of two alternative cell fate transcriptional programmes, OC vs macrophage, with repression of the latter following activation of the former. Both programmes are regulated in a non-redundant manner by increased chromatin binding of Brd2 at promoters and of Brd4 at enhancers/super-enhancers. Myc, the top RANKL-induced TF, regulates OC development in co-operation with Brd2/4 and Max and by establishing negative and positive regulatory loops with other lineage-affiliated TFs. These insights into the transcriptional regulation of osteoclastogenesis suggest the clinical potential of selective targeting of Brd2/4 to abrogate pathological OC activation., Graphical Abstract, Highlights • Upregulation of osteoclast lineage commitment TFs occurs, Biological Sciences; Developmental Biology; Bioinformatics; Omics; Transcriptomics

In the phase 3 BOSTON study, patients with multiple myeloma (MM) after 1–3 prior regimens were randomized to once-weekly selinexor (an oral inhibitor of exportin 1 [XPO1]) plus bortezomib-dexamethasone (XVd) or twice-weekly bortezomib-dexamethasone (Vd). Compared with Vd, XVd was associated with significant improvements in median progression-free survival (PFS), overall response rate (ORR), and lower rates of peripheral neuropathy, with trends in overall survival (OS) favoring XVd. In BOSTON, 141 (35.1%) patients had MM with high-risk (presence of del[17p], t[4;14], t[14;16], or ≥4 copies of amp1q21) cytogenetics (XVd, n=70; Vd, n=71), and 261 (64.9%) exhibited standard-risk cytogenetics (XVd, n=125; Vd, n=136). Among patients with high-risk MM, median PFS was 12.91 months for XVd and 8.61 months for Vd (HR, 0.73 [95% CI, (0.4673, 1.1406)], p=0.082), and ORRs were 78.6% and 57.7%, respectively (OR 2.68; p= 0.004). In the standard-risk subgroup, median PFS was 16.62 months for XVd and 9.46 months for Vd (HR 0.61; p=0.004), and ORRs were 75.2% and 64.7%, respectively (OR 1.65; p=0.033). The safety profiles of XVd and Vd in both subgroups were consistent with the overall population. These data suggest that selinexor can confer benefits to patients with MM regardless of cytogenetic risk. ClinicalTrials.gov identifier: NCT03110562.

Multiple myeloma is a malignancy of plasma cells initiated and driven by primary and secondary genetic events. However, myeloma plasma cell survival and proliferation might be sustained by non-genetic drivers. Z-DNA-binding protein 1 (ZBP1; also known as DAI) is an interferon-inducible, Z-nucleic acid sensor that triggers RIPK3-MLKL-mediated necroptosis in mice. ZBP1 also interacts with TBK1 and the transcription factor IRF3 but the function of this interaction is unclear, and the role of the ZBP1-IRF3 axis in cancer is not known. Here we show that ZBP1 is selectively expressed in late B-cell development in both human and murine cells and it is required for optimal T-cell-dependent humoral immune responses. In myeloma plasma cells, the interaction of constitutively expressed ZBP1 with TBK1 and IRF3 results in IRF3 phosphorylation. IRF3 directly binds and activates cell cycle genes, in part through co-operation with the plasma cell lineage-defining transcription factor IRF4, thereby promoting myeloma cell proliferation. This generates a novel, potentially therapeutically targetable and relatively selective myeloma cell addiction to the ZBP1-IRF3 axis. Our data also show a noncanonical function of constitutive ZBP1 in human cells and expand our knowledge of the role of cellular immune sensors in cancer biology.

ZBP1 is an inducible, non-constitutively expressed cellular nucleic acid sensor that triggers type I interferon (IFN) responses via phosphorylation and activation of the transcription factor (TF) IRF3 by TBK1. However, the role of the ZBP1-IRF3 axis in cancer is not known. Here we show that ZBP1 is selectively and constitutively expressed in late B cell development and it is required for optimal T cell-dependent humoral immune responses. In the plasma cell (PC) cancer multiple myeloma, interaction of constitutively expressed ZBP1 with TBK1 and IRF3 results in IRF3 phosphorylation. Notably, rather than IFN type I response genes, IRF3 directly activates, in part through co-operation with the PC lineage-defining TF IRF4, cell cycle genes thus promoting myeloma cell proliferation. This generates a novel, potentially therapeutically targetable and relatively selective myeloma cell addiction to the ZBP1-IRF3 axis. These data expand our knowledge of the role of cellular immune sensors in cancer biology.

Multiple myeloma is a genetically heterogeneous cancer of the bone marrow plasma cells (PC). Myeloma initiating genetic events define subgroups (MIE) and drive distinct oncogenic transcriptomes that converge into a mutually exclusive overexpression of CCND1 and CCND2 oncogenes. Here, with reference to normal PC, we dissect how MIE impact the chromatin regulatory landscape of MM. We find that chromatin accessibility combined with transcriptome profiling classifies myeloma genetic subgroups, while in a topologically constrained manner, distal rather than proximal regulatory elements influence myeloma transcriptomes. Across and within MIE-defined subgroups, genes and pathways critical for myeloma biology can be linked to developmentally activated or de novo formed enhancers. We show that existing transcription factors, co-opted to organise highly ordered, aberrant regulatory networks, generate known and novel myeloma cell dependencies and help identify prognostic markers. Finally, we discover and functionally validate the critical enhancer that regulates ectopic expression of CCND2 in MM.

Summary Background Selinexor combined with dexamethasone has shown activity in patients with heavily pre-treated multiple myeloma. In a phase 1b/2 study, the combination of oral selinexor with bortezomib (a proteasome inhibitor) and dexamethasone induced high response rates with low rates of peripheral neuropathy, the main dose-limiting toxicity of bortezomib. We aimed to evaluate the clinical benefit of weekly selinexor, bortezomib, and dexamethasone versus standard bortezomib and dexamethasone in patients with previously treated multiple myeloma. Methods This phase 3, randomised, open-label trial was done at 123 sites in 21 countries. Patients aged 18 years or older, who had multiple myeloma, and who had previously been treated with one to three lines of therapy, including proteasome inhibitors, were randomly allocated (1:1) to receive selinexor (100 mg once per week), bortezomib (1·3 mg/m2 once per week), and dexamethasone (20 mg twice per week), or bortezomib (1·3 mg/m2 twice per week for the first 24 weeks and once per week thereafter) and dexamethasone (20 mg four times per week for the first 24 weeks and twice per week thereafter). Randomisation was done using interactive response technology and stratified by previous proteasome inhibitor therapy, lines of treatment, and multiple myeloma stage. The primary endpoint was progression-free survival in the intention-to-treat population. Patients who received at least one dose of study treatment were included in the safety population. This trial is registered at ClinicalTrials.gov , NCT03110562 . The trial is ongoing, with 55 patients remaining on randomised therapy as of Feb 20, 2020. Findings Of 457 patients screened for eligibility, 402 were randomly allocated—195 (49%) to the selinexor, bortezomib, and dexamethasone group and 207 (51%) to the bortezomib and dexamethasone group—and the first dose of study medication was given between June 6, 2017, and Feb 5, 2019. Median follow-up durations were 13·2 months [IQR 6·2–19·8] for the selinexor, bortezomib, and dexamethasone group and 16·5 months [9·4–19·8] for the bortezomib and dexamethasone group. Median progression-free survival was 13·93 months (95% CI 11·73–not evaluable) with selinexor, bortezomib, and dexamethasone and 9·46 months (8·11–10·78) with bortezomib and dexamethasone (hazard ratio 0·70 [95% CI 0·53–0·93], p=0·0075). The most frequent grade 3–4 adverse events were thrombocytopenia (77 [39%] of 195 patients in the selinexor, bortezomib, and dexamethasone group vs 35 [17%] of 204 in the bortezomib and dexamethasone group), fatigue (26 [13%] vs two [1%]), anaemia (31 [16%] vs 20 [10%]), and pneumonia (22 [11%] vs 22 [11%]). Peripheral neuropathy of grade 2 or above was less frequent with selinexor, bortezomib, and dexamethasone (41 [21%] patients) than with bortezomib and dexamethasone (70 [34%] patients; odds ratio 0·50 [95% CI 0·32–0·79], p=0·0013). 47 (24%) patients in the selinexor, bortezomib, and dexamethasone group and 62 (30%) in the bortezomib and dexamethasone group died. Interpretation A once-per-week regimen of selinexor, bortezomib, and dexamethasone is a novel, effective, and convenient treatment option for patients with multiple myeloma who have received one to three previous lines of therapy. Funding Karyopharm Therapeutics.

Contains fulltext : 218311.pdf (Publisher’s version ) (Open Access) Plerixafor plus granulocyte-colony stimulating factor (G-CSF) enhances the mobilization of hematopoietic stem cells (HSCs) for collection and subsequent autologous hematopoietic stem cell transplantation (HSCT) in patients with multiple myeloma (MM). This international, multicenter, noninterventional registry study (NCT01362972), evaluated long-term outcomes for MM patients who received plerixafor versus other mobilization regimens. The comparisons were: G-CSF + plerixafor (G-CSF + P) versus G-CSF-; G-CSF + P versus G-CSF + chemotherapy (G-CSF + C); and G-CSF + P + C versus G-CSF + C. Propensity score matching was used to balance groups. Primary outcome measures were progression free survival (PFS), overall survival (OS), and cumulative incidence of relapse (CIR) after transplantation. After propensity matching, 77 versus 41 patients in the G-CSF + P versus G-CSF cohorts, 129 versus 129 in the G-CSF + P versus G-CSF + C cohorts, and 117 versus 117 in the G-CSF + P + C versus G-CSF + C cohorts were matched, respectively. Propensity score matching resulted in a smaller sample size and imbalances were not completely overcome. For both PFS and OS, the upper limits of the hazard ratio 95% confidence intervals exceeded prespecified boundaries; noninferiority was not demonstrated. CIR rates were higher in the plerixafor cohorts. G-CSF + P remains an option for the mobilization of HSCs in poor mobilizers with MM with no substantial differences in PFS, OS, and CIR in comparison with other regimens.

Cellular protein homeostasis (proteostasis) depends on the controlled degradation of proteins that are damaged or no longer required by the ubiquitin-proteasome system (UPS). The 26S proteasome is the principal executer of substrate-specific proteolysis in eukaryotic cells and regulates a myriad of cellular functions. Proteasome inhibitors were initially developed as chemical tools to study proteasomal function but rapidly became widely used anticancer drugs that are now used at all stages of treatment for the bone marrow cancer multiple myeloma (MM). Here, we review the mechanisms of action of proteasome inhibitors that underlie their preferential toxicity to MM cells, focusing on endoplasmic reticulum stress, depletion of amino acids, and effects on glucose and lipid metabolism. We also discuss mechanisms of resistance to proteasome inhibition such as autophagy and metabolic rewiring and what lessons we may learn from the success and failure of proteasome inhibition in MM for treating other cancers with proteostasis-targeting drugs.

Cardiovascular disease in patients with multiple myeloma may derive from factors unrelated to the disease (age, diabetes, dyslipidemia, obesity, prior cardiovascular diseases), related to the disease (cardiac AL-amyloidosis, hyperviscosity, high-output failure, arteriovenous shunting, anemia, renal dysfunction) and/or related to anti-myeloma treatment (anthracyclines, corticosteroids, alkylating agents, immunomodulatory drugs, proteasome inhibitors). Good knowledge of cardiovascular events, effective dose reductions, prevention and management of early and late cardiovascular side effects of chemotherapeutic agents are essential in current clinical practice. Myeloma experts are obliged to carefully balance the efficacy and toxicity of drugs for each individual patient. This review summarizes current data and novel insights into cardiovascular adverse events of today's anti-myeloma treatment, focusing on carfilzomib, as a starting point for developing consensus recommendations on preventing and managing cardiovascular side effects in patients with multiple myeloma.

Survival of myeloma patients has greatly improved with the use of autologous stem cell transplantation and novel agents, such as proteasome inhibitors, immunomodulatory drugs and monoclonal antibodies. Compared to bortezomib- and lenalidomide-based regimens alone, the addition of high-dose melphalan followed by autologous transplantation significantly improves progression-free survival, although an overall survival benefit was not observed in all trials. Moreover, follow up of recent trials is still too short to show any difference in survival. In the light of these findings, novel agent-based induction followed by autologous transplantation is considered the standard upfront treatment for eligible patients (level of evidence: 1A). Post-transplant consolidation and maintenance treatment can further improve patient outcome (1A). The availability of several novel agents has led to the development of multiple combination regimens such as salvage treatment options. In this context, the role of salvage autologous transplantation and allotransplant has not been extensively evaluated. In the case of prolonged remission after upfront autologous transplantation, another autologous transplantation at relapse can be considered (2B). Patients who experience early relapse and/or have high-risk features have a poor prognosis and may be considered as candidates for clinical trials that, in young and fit patients, may also include an allograft in combination with novel agents (2B). Ongoing studies are evaluating the role of novel cellular therapies, such as inclusion of antibody-based triplets and quadruplets, and chimeric antigen receptor-T cells. Despite encouraging preliminary results, longer follow up and larger patient numbers are needed before the clinical use of these novel therapies can be widely recommended.

Background Extensive protein synthesis in multiple myeloma (MM) cells renders them vulnerable to proteasome inhibitors (PI), a cornerstone of anti-myeloma therapy. However, relapse is inevitable and PI resistance remains a major barrier to improving outcomes. Adaptive responses to PI include upregulation of autophagy, another major degradation pathway in cells. We hypothesised that autophagy inhibition increases cell death and impedes recovery of MM cells exposed to Carfilzomib (K), a second generation PI effective in newly diagnosed and relapsed/refractory MM. Methods: Human myeloma cell lines (HMCL) and patient samples were exposed to a 1-hour pulse of K to mimic pharmacokinetics, ± autophagy inhibitors (AI) vacuolar protein sorting kinase 34 inhibitor (VPS34i) or unc-51 like autophagy initiating kinase inhibitor (ULKi). Apoptosis was assessed by Annexin V/Propidium iodide (AnV/PI) flow cytometry (FC) and autophagic flux by western blotting (WB) and FC for light chain 3B (LC3B) ± bafilomycin (B). Cell cycle was examined by FC using KI67/PI. Results: Basal autophagic flux was seen in all HMCL (MM1s, H929, KMS12BM) tested (±B). Autophagic flux increased in response to K: MM1s mean fluorescence intensity (MFI) control (CTL) 318±28 vs K 567±72, (mean±SEM),p=0.01, n=6). Autophagy was inhibited in all 3 HMCL with AI. Combined exposure to K and AI (VPS34i or ULKi) increased time dependent apoptosis in all HMCL tested: MM1s 31±8% (K) vs 58±9% (K+VPS34i), p=0.03, (n=3), and 13±0.4% (K) vs 63±16% (K+ULKi), p=0.03 (n=3), (K 10nM, AI 1uM) 48 hours(h) post K exposure. Basal autophagic flux was detected in all CD138+ primary MM patient samples tested by LC3B FC assay (MFI CTL B- 407±57 vs B+ 1081±125, p K treated MM1s cells were examined for kinetics of ubiquitinated protein build up and autophagic induction by WB. Increased ubiquitinated proteins were detectable up to 24h post K pulse, whilst autophagic flux increased up to 72h but returned to baseline thereafter (n=3). MM1s cells were treated with K±VPS34i for up to 7 days and apoptosis, absolute cell number and cell cycle assessed. In K treated cells, apoptosis was maximal at 72h but declined thereafter. Viable cell numbers fell initially but increased after 96h, indicating cell recovery. However, in MM1s cells treated with K+VPS34i/ULKi, apoptosis was enhanced with a rapid loss of viable cells (Fig 2) and viable cell numbers remained low at all timepoints (Fig 3). Cell cycle assays confirmed persistent G0/G1 arrest in MM1s cells treated with K+VPS34i or ULKi at all timepoints, whilst cell proliferation recovered in K treated cells on day 3, (15±3% cells in S/G2M in K treated cells vs 2±0.4% with K+VPS34i, p=0.02, n=4, 11±3% in S/G2M with K vs 1± 0.7% with K+ULKi, p=0.04, n=3, day 4)(Fig 4). To confirm that effects of AI were mediated via autophagy, KMS28PE (ATG12 null HMCL) were treated with K±VPS34i. These autophagy depleted cells showed limited basal or K induced autophagic flux and addition of VPS34i to K had no effect on apoptosis or cell cycle. Conclusion MM cells displayed active autophagic flux that increased with K treatment. Inhibition of autophagy increased K induced apoptosis, prolonged K-induced cell cycle arrest and prevented MM cell recovery. Addition of AI to K increased cytotoxicity in patient samples and many patients showed sensitivity to AI alone; these effects correlated with basal autophagic flux. These data suggest that autophagy plays a vital role in cell recovery from proteasome inhibition independent of proteotoxic stress. Dual inhibition of the proteasome and autophagosome may therefore help overcome PI resistance, which remains an unmet need in MM. Figure 1 Figure 1. Disclosures Auner: Takeda, Karyopharm: Other: Advisory role; Amgen: Research Funding; Janssen: Speakers Bureau. Khwaja: Pfizer: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Astellas: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Abbvie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Yong: Sanofi: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Takeda: Honoraria; GSK: Honoraria; Amgen: Honoraria; BMS: Research Funding; Autolus: Research Funding.

Introduction: Treatment of multiple myeloma (MM) has greatly improved over the last two decades. However, most pts will relapse and develop refractory disease. Most anti-cancer regimens require dose modifications (interruption, reduction, or discontinuation) during the treatment course in order to optimize the therapeutic window; appropriate modifications improve tolerability while maintaining anti-cancer activity. Selinexor, an oral selective inhibitor of XPO1-mediated nuclear export (SINE) compound, enforces the nuclear retention and functional activation of tumor suppressor proteins within the nucleus and prevents the translation of oncoproteins. The combination of once weekly (QW) selinexor, QW bortezomib, and dexamethasone (XVd) is FDA approved for previously treated MM. Compared to standard twice weekly (BIW) bortezomib plus dexamethasone (Vd) and using 40% less bortezomib and 25% less dexamethasone, XVd demonstrated significantly prolonged median progression-free survival (PFS) and time-to-next-treatment (TTNT), increased the overall response rate (ORR), reduced rates of peripheral neuropathy, and showed a trend towards improved overall survival (OS) in the Phase 3 randomized BOSTON study (NCT03110562). The recommended starting dose of selinexor in XVd is 100mg QW, but the median dose administered in BOSTON was 80 mg QW. Here, we analyzed the efficacy outcomes and adverse events (AEs) in pts whose dose was reduced compared to those where it was not. Methods: The BOSTON study consisted of two arms: pts treated with selinexor QW (100mg), bortezomib QW (1.3mg/m 2) and dexamethasone BIW (20 mg) (XVd; n=195 in the intention-to-treat [ITT] population) compared to standard BIW Vd. Results: Of the XVd pts in the BOSTON study, 126 had a dose reduction of selinexor and 69 did not. The median age was 66.0 in both groups (range: with reduction, 47-87; without, 40-84) and the median number of prior therapies was 1.0 (range, 1-3) for both groups (Table 1). The median time to dose reduction in these pts was 68 days (range, 8-561 days). The median duration of study treatment for these pts was 34.5 weeks (range, 3-120 weeks) compared to 20.0 weeks (range, 1-118) in pts with no dose reduction. In the group with dose reduction, the median dose of selinexor received per week was 71.3 mg (range, 29.7, 101.4) compared to 100 mg (range, 33.3, 136.7) in pts with no reduction. Pts who dose reduced had a median PFS of 16.6 months compared to 9.2 months in pts who did not (one-sided p value, The most common adverse events (AEs; dose reduction and without dose reduction) of any grade were thrombocytopenia (69.8% and 42.0%), nausea (55.6% and 40.6%), and fatigue (49.2% and 29.0%). The rate of treatment discontinuation in the dose reduced group was 24.6% and 14.5% without dose reductions. In the dose reduced group, there were 6 (4.8%) deaths and 6 (8.7%) in the group with no dose reduction. As pts with a dose reduction stayed on therapy for a prolonged period of time, to best understand the impact of dose reduction on the AE, we present the duration-adjusted incidence rates of AEs of clinical interest. The duration-adjusted incidence rates of AE were considerably lower after dose reduction of selinexor compared to the rates on or before dose reduction: thrombocytopenia (62.5% vs 47.6%), nausea (31.6% vs 7.3%), fatigue (28.1% vs 9.9%), decreased appetite (21.5% vs 6.4%), anemia (17.9% vs 10.3%), and diarrhea (12.9% vs 5.2) (Table 3). Conclusions: While all pts on XVd initiated therapy at 100mg selinexor QW, and it was associated with very low rates of progressive disease (1 in 195 pts), appropriate dose reductions of selinexor were associated with a longer PFS, DOR, and TTNT, and significantly reduced AE with improved tolerability, highlighting dose reductions as an important tool to personalize and optimize the therapeutic window for pts with RRMM. Figure 1 Figure 1. Disclosures Jagannath: Bristol Myers Squibb: Consultancy; Janssen Pharmaceuticals: Consultancy; Karyopharm Therapeutics: Consultancy; Legend Biotech: Consultancy; Sanofi: Consultancy; Takeda: Consultancy. Badros: Janssen: Research Funding; GlaxoSmithKline: Research Funding; J&J: Research Funding; BMS: Research Funding. Levy: Takeda, Celgene, Seattle Genetics, AbbVie, Jazz Pharmaceuticals, Gilead Sciences, Bristol-Myers Squibb, Amgen, Spectrum Pharmaceuticals,Janssen.: Consultancy. Moreau: Celgene BMS: Honoraria; Oncopeptides: Honoraria; Amgen: Honoraria; Sanofi: Honoraria; Abbvie: Honoraria; Janssen: Honoraria. Delimpasi: Takeda: Honoraria, Speakers Bureau; Janssen: Honoraria, Speakers Bureau; Amgen: Honoraria, Speakers Bureau. Kriachok: Takeda, Roche, Abbivie, Janssen, MSD: Consultancy; Takeda, Roche, Abbvie, Janssen, MSD, Pfizer: Honoraria, Speakers Bureau. Gavriatopoulou: Takeda: Honoraria; Sanofi: Honoraria; GSK: Honoraria; Janssen: Honoraria; Karyopharm: Honoraria; Genesis: Honoraria; Amgen: Honoraria. Auner: Janssen: Speakers Bureau; Amgen: Research Funding; Takeda, Karyopharm: Other: Advisory role. Leleu: Bristol-Myers Squibb: Honoraria; Carsgen Therapeutics Ltd: Honoraria; Celgene: Honoraria; Gilead Sciences: Honoraria; Janssen-Cilag: Honoraria; Karyopharm Therapeutics: Honoraria; Merck: Honoraria; Mundipharma: Honoraria; Novartis: Honoraria; Oncopeptides: Honoraria; Pierre Fabre: Honoraria; Roche: Honoraria; Sanofi: Honoraria; Amgen: Honoraria; AbbVie: Honoraria; Takeda: Honoraria, Other: Non-financial support. Usenko: Janssen: Consultancy, Honoraria, Other: Clinical Trials Investigator; AbbVie: Consultancy, Honoraria, Other: Clinical Trials Investigator; Pfizer: Consultancy, Honoraria; Acerta: Other: Clinical Trials Investigator; Ascentage: Other: Clinical Trials Investigator; Celgene: Other: Clinical Trials Investigator; Il-Yang: Other: Clinical Trials Investigator; Karyopharm: Other: Clinical Trials Investigator; Oncopeptides: Other: Clinical Trials Investigator; Rigel: Other: Clinical Trials Investigator; Takeda: Other: Clinical Trials Investigator; UCB: Other: Clinical Trials Investigator. Hajek: Janssen: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Research Funding; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Consultancy, Honoraria; Pharma MAR: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; BMS: Consultancy, Honoraria, Research Funding; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Venner: BMS: Honoraria; Amgen: Research Funding; Celgene: Research Funding; Amgen: Honoraria; Takeda: Honoraria; Janssen: Honoraria; Sanofi: Honoraria; Pfizer: Honoraria. Garg: University Hospital Leicester: Current Employment; Amgen Janssen Novartis Sanofi Takeda: Honoraria; Takeda Janssen Novartis Sanofi: Other: Travel Accommodations, Expenses. Gironella Mesa: BMS, Janssen: Honoraria. Jurczyszyn: Janssen-Cilag, Amgen: Honoraria, Speakers Bureau. Robak: Biogen, Abbvie, Octapharma, Janssen: Honoraria, Other: Advisory board; AstraZeneca, Abbvie, Janssen, Octapharma, Gilead,Oncopeptides AB, Pharmacyclics, Pfizer, GlaxoSmithKline, Biogen: Research Funding; Medical University of Lodz: Current Employment. Galli: BMS, Celgene, Janssen, Sanofi, Takeda: Honoraria. Radinoff: Janssen, Pfizer, Novartis, Servier etc.: Consultancy, Honoraria; Amgen, Bayer, Takeda, etc.: Research Funding; the Bulgarian Minister of Health: Membership on an entity's Board of Directors or advisory committees. Liberati: abbvie, amgen, archigen, beigene, BMS, celgene, DR REDDY'S LABORATORIES SPA, fibrogen, glaxo, Janssen, Karyopharm, Morphosys, Novartis, Onconova, Oncopeptides ab, Roche, Sanophi, Secura Bio, Takeda, Verastem,: Research Funding. Quach: Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Sanofi: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Antengene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen/Cilag: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; GlaxoSmithKline: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol Myers Squibb: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees; Karyopharm: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; CSL: Consultancy, Membership on an entity's Board of Directors or advisory committees. Bila: Takeda, AMGEN, Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Katodritou: GSK, Amgen, Karyopharm, Abbvie, Janssen-Cilag, Genesis Pharma, Sanofi: Honoraria, Research Funding. DeCastro: Karyopharm: Current Employment, Current equity holder in publicly-traded company. Chai: Karyopharm: Current Employment. Van Domelen: Karyopharm: Current Employment, Current equity holder in publicly-traded company. Mishal: Karyopharm: Current Employment. Bentur: Karyopharm Therapeutics: Current Employment, Current equity holder in publicly-traded company. Shah: Karyopharm: Current Employment. Shacham: Karyopharm: Current Employment, Current equity holder in publicly-traded company, Patents & Royalties: (8999996, 9079865, 9714226, PCT/US12/048319, and I574957) on hydrazide containing nuclear transport modulators and uses, and pending patents PCT/US12/048319, 499/2012, PI20102724, and 2012000928) . Kauffman: Karyopharm Therapeutics Inc.: Current Employment, Current equity holder in publicly-traded company. Richardson: GlaxoSmithKline: Consultancy; Sanofi: Consultancy; AstraZeneca: Consultancy; Regeneron: Consultancy; Karyopharm: Consultancy, Research Funding; Janssen: Consultancy; AbbVie: Consultancy; Protocol Intelligence: Consultancy; Secura Bio: Consultancy; Takeda: Consultancy, Research Funding; Celgene/BMS: Consultancy, Research Funding; Oncopeptides: Consultancy, Research Funding; Jazz Pharmaceuticals: Consultancy, Research Funding.

Introduction: Patients with multiple myeloma (MM) have a high rate of relapse resulting in a need for multiple lines of therapy. In contrast to MM with standard risk cytogenetics (SR-Cyto), high-risk cytogenetics (HR-Cyto) in MM such as del(17p), t(4;14), t(14;16), and gain(1q) (≥3 copies), can result in shorter progression-free survival (PFS) and overall survival (OS) with less durable responses. Treatment regimens that can overcome the negative effect of HR-Cyto abnormalities are required to address this area of unmet medical need. Exportin 1 (XPO1), is overexpressed in many hematologic and solid tumor malignancies including MM, and exports tumor suppressor proteins from the nucleus to the cytoplasm, leading to their inactivation. Elevated levels of XPO1 are correlated with more aggressive MM and resistance to therapy and confers a poor prognosis. The potent oral XPO1 inhibitor, selinexor, has been approved as a triplet combination with bortezomib and dexamethasone for previously-treated MM. In the Phase 3 BOSTON study, treatment with XVd in patients with previously treated MM significantly prolonged median PFS and improved the overall response rate (ORR), with a trend towards a prolonged OS amongst all patients as well as those with HR cytogenetics. Methods: We performed post hoc analyses on patients with previously-treated MM from the XVd arm of the Phase 1b/2 study STOMP (NCT02343042) and the Phase 3 BOSTON (NCT03110562) study to determine the effects of cytogenetic abnormalities on outcomes. The HR-Cyto group included patients with at least one of the following cytogenetic abnormalities at initial diagnosis or screening: del(17p), t(4;14), t(14;16), or gain(1q) (≥3 copies). Efficacy was based on independent review committee. Results: A total of 106 patients with HR-Cyto were identified, including del(17p) (n=25), t(4;14) (n=25), t(14;16) (n=10), and gain(1q) (n=80). There were 131 patients classified as SR-Cyto including those with unknown cytogenetics. Baseline demographics were similar between groups with median age of 66 years old (range 40-87). Patients with HR-Cyto had a median PFS of 12.9 months and patients with SR-Cyto had a median PFS of 16.6 months; PFS on the BOSTON Vd control arm were 8.6 and 9.5 months with HR- and SR-Cyto, respectively. Of the individual abnormalities, a PFS of 13.2 and 13.9 months was observed in the t(4;14) and gain1q subgroups, respectively. Of the HR-Cyto subgroups with more than 10 patients, a similar median OS was observed in comparison to SR-Cyto and ranged from 20.4 months to not reached. The response of XVd treatment was maintained across HR-Cyto risk subgroups, with an ORR of 76.4% overall and the following values for subgroups: del(17p) (72.0%), t(4;14) (88.0%), and gain1q (73.8%). The ORR of the SR group was 69.5%. Of all patients that received XVd, there were 6 CRs (5.7%) and 32 VGPRs (30.2%) in the HR group and 9 CRs (6.9%) and 29 VGPRs (22.1%) in the SR group. The ORRs on the BOSTON Vd control arm were 57.7% and 64.7% for HR- and SR-Cyto, respectively. The rates of the most common treatment emergent adverse events (TEAEs) of any grade were similar across risk groups (HR- vs SR-Cyto): thrombocytopenia (65.1% vs. 54.2%), nausea (53.8% vs. 53.4%), fatigue (47.2% vs. 45.0%) decreased appetite (37.7% vs. 42.0%) and anemia (34.6% vs 40.5%). Rates of AEs of any grade peripheral neuropathy (PN) were 35.8% overall, 40.0% in del(17p), t(4;14) (40.0%), t(14;16) (30.0%), gain(1q) (38.8%), and 23.7% in the SR group. The rates of PN in the HR and SR groups of the XVd arm of the BOSTON and STOMP studies were 37.1% and 29.6% and 11.1% and 15.2%, respectively. The corresponding rates for Vd alone in the BOSTON study were 48.6% and 47.0%. Conclusions: Patients with MM with HR-Cyto treated with XVd demonstrated a comparable ORR and PFS, with a manageable safety profile compared to patients with SR-Cyto, supporting the use of XVd in patients with any cytogenetic profile. These results are consistent with the distinct and broad mechanism of action associated with XPO1 inhibition and the use of the agent in earlier lines of therapy. Further assessment of selinexor in combination with other therapies in patients with MM across the entire cytogenetic spectrum is warranted. Figure 1 Figure 1. Disclosures Bahlis: Sanofi: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; GlaxoSmithKline: Consultancy, Honoraria; Genentech: Consultancy; BMS/Celgene: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria; Karyopharm: Consultancy, Honoraria. Richard: Karyopharm, Janssen: Honoraria. White: Amgen, Antengene, BMS/Celgene, Forus, GSK, Janssen, Karyopharm, Sanofi, Takeda: Consultancy, Honoraria. Chen: Gilead: Research Funding; BMS, Janssen, Abbvie, Novartis, Gilead, AstraZeneca: Consultancy. Delimpasi: Amgen: Honoraria, Speakers Bureau; Janssen: Honoraria, Speakers Bureau; Takeda: Honoraria, Speakers Bureau. Sutherland: Amgen: Consultancy; Janssen: Consultancy, Research Funding; GSK: Research Funding; Celgene: Consultancy; Karyopharm: Research Funding. Sebag: Janssen: Research Funding; Bristol Myers-Squibb: Consultancy, Honoraria; Karyopharm Therapeutics: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Sanofi: Consultancy, Honoraria. Gavriatopoulou: GSK: Honoraria; Janssen: Honoraria; Takeda: Honoraria; Genesis: Honoraria; Sanofi: Honoraria; Karyopharm: Honoraria; Amgen: Honoraria. Lentzsch: Oncopeptides: Consultancy; Sanofi: Consultancy, Research Funding; Karyopharm: Consultancy, Research Funding; Takeda: Consultancy; GSK: Consultancy; AbbVie: Consultancy; Celularity: Consultancy; Janssen: Consultancy; Caelum Biosciences: Consultancy, Current holder of individual stocks in a privately-held company; Ossium Health: Consultancy; Magenta Therapeutics: Current equity holder in publicly-traded company; Kadmon: Current equity holder in publicly-traded company. Chari: Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees; Sanofi Genzyme: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Research Funding; Oncopeptides: Consultancy, Membership on an entity's Board of Directors or advisory committees; Karyopharm: Consultancy, Membership on an entity's Board of Directors or advisory committees; Secura Bio: Consultancy, Membership on an entity's Board of Directors or advisory committees; Shattuck Labs: Consultancy, Membership on an entity's Board of Directors or advisory committees; AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Research Funding; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; GlaxoSmithKline: Consultancy, Membership on an entity's Board of Directors or advisory committees; Millenium/Takeda: Consultancy, Research Funding; Pharmacyclics: Research Funding; Janssen Oncology: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS/Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Antengene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees, Research Funding. Kriachok: Takeda, Roche, Abbvie, Janssen, MSD, Pfizer: Honoraria, Speakers Bureau; Takeda, Roche, Abbivie, Janssen, MSD: Consultancy. Dimopoulos: BMS: Honoraria; Janssen: Honoraria; Amgen: Honoraria; Takeda: Honoraria; Beigene: Honoraria. Auner: Janssen: Speakers Bureau; Amgen: Research Funding; Takeda, Karyopharm: Other: Advisory role. Leleu: Bristol-Myers Squibb: Honoraria; Carsgen Therapeutics Ltd: Honoraria; Celgene: Honoraria; Gilead Sciences: Honoraria; Janssen-Cilag: Honoraria; Karyopharm Therapeutics: Honoraria; Merck: Honoraria; Mundipharma: Honoraria; Novartis: Honoraria; Oncopeptides: Honoraria; Pierre Fabre: Honoraria; Roche: Honoraria; Sanofi: Honoraria; Amgen: Honoraria; AbbVie: Honoraria; Takeda: Honoraria, Other: Non-financial support. Usenko: Janssen: Consultancy, Honoraria, Other: Clinical Trials Investigator; AbbVie: Consultancy, Honoraria, Other: Clinical Trials Investigator; Pfizer: Consultancy, Honoraria; Acerta: Other: Clinical Trials Investigator; Ascentage: Other: Clinical Trials Investigator; Celgene: Other: Clinical Trials Investigator; Il-Yang: Other: Clinical Trials Investigator; Karyopharm: Other: Clinical Trials Investigator; Oncopeptides: Other: Clinical Trials Investigator; Rigel: Other: Clinical Trials Investigator; Takeda: Other: Clinical Trials Investigator; UCB: Other: Clinical Trials Investigator. Hajek: Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharma MAR: Consultancy, Honoraria; Novartis: Consultancy, Research Funding; AbbVie: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding. Venner: Janssen: Honoraria; Amgen: Honoraria; Takeda: Honoraria; Celgene: Research Funding; Amgen: Research Funding. Garg: Takeda Janssen Novartis Sanofi: Other: Travel Accommodations, Expenses; Amgen Janssen Novartis Sanofi Takeda: Honoraria; University Hospital Leicester: Current Employment. Quach: Antengene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Sanofi: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen/Cilag: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; GlaxoSmithKline: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Karyopharm: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol Myers Squibb: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees; CSL: Consultancy, Membership on an entity's Board of Directors or advisory committees. Jagannath: Karyopharm Therapeutics: Consultancy; Bristol Myers Squibb: Consultancy; Legend Biotech: Consultancy; Janssen Pharmaceuticals: Consultancy; Sanofi: Consultancy; Takeda: Consultancy. Moreau: Celgene BMS: Honoraria; Sanofi: Honoraria; Janssen: Honoraria; Abbvie: Honoraria; Amgen: Honoraria; Oncopeptides: Honoraria. Levy: Takeda, Celgene, Seattle Genetics, AbbVie, Jazz Pharmaceuticals, Gilead Sciences, Bristol-Myers Squibb, Amgen, Spectrum Pharmaceuticals,Janssen.: Consultancy. Badros: J&J: Research Funding; Janssen: Research Funding; BMS: Research Funding; GlaxoSmithKline: Research Funding. Anderson: Celgene, BMS, Janssen, GSK, Karyopharm, Oncopeptides, Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Mateos: Oncopeptides: Honoraria; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sea-Gen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene - Bristol Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees; Adaptive Biotechnologies: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Regeneron: Honoraria, Membership on an entity's Board of Directors or advisory committees; GSK: Honoraria; Bluebird bio: Honoraria; AbbVie: Honoraria; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Oncopeptides: Honoraria, Membership on an entity's Board of Directors or advisory committees. Cavo: AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Sanofi: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; GlaxoSmithKline: Consultancy, Honoraria; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Adaptive Biotechnologies: Consultancy, Honoraria; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel Accommodations, Speakers Bureau; Novartis: Honoraria; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES, Speakers Bureau; Bristol-Myers Squib: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. DeCastro: Karyopharm: Current Employment, Current equity holder in publicly-traded company. Chai: Karyopharm: Current Employment. Van Domelen: Karyopharm: Current Employment, Current equity holder in publicly-traded company. Mishal: Karyopharm: Current Employment. Bentur: Karyopharm Therapeutics: Current Employment, Current equity holder in publicly-traded company. Shah: Karyopharm: Current Employment. Shacham: Karyopharm: Current Employment, Current equity holder in publicly-traded company, Patents & Royalties: (8999996, 9079865, 9714226, PCT/US12/048319, and I574957) on hydrazide containing nuclear transport modulators and uses, and pending patents PCT/US12/048319, 499/2012, PI20102724, and 2012000928) . Kauffman: Karyopharm Therapeutics Inc.: Current Employment, Current equity holder in publicly-traded company. Richardson: Secura Bio: Consultancy; Sanofi: Consultancy; AstraZeneca: Consultancy; Oncopeptides: Consultancy, Research Funding; Janssen: Consultancy; Protocol Intelligence: Consultancy; Takeda: Consultancy, Research Funding; Regeneron: Consultancy; Celgene/BMS: Consultancy, Research Funding; GlaxoSmithKline: Consultancy; AbbVie: Consultancy; Karyopharm: Consultancy, Research Funding; Jazz Pharmaceuticals: Consultancy, Research Funding.

Melphalan at a dose of 200 mg/m2 is standard conditioning prior to autologous hematopoietic stem cell transplantation for multiple myeloma, but a dose of 140 mg/m2 is often used in clinical practice in patients perceived to be at risk of excess toxicity. To determine whether melphalan 200 mg/m2 and melphalan 140 mg/m2 are equally effective and tolerable in clinically relevant patient subgroups we analyzed 1964 first single autologous transplantation episodes using a series of Cox proportional-hazards models. Overall survival, progression-free survival, cumulative incidence of relapse, non-relapse mortality, hematopoietic recovery and second primary malignancy rates were not significantly different between the melphalan 140 mg/m2 (n=245) and melphalan 200 mg/m2 (n=1719) groups. Multivariable subgroup analysis showed that disease status at transplantation interacted with overall survival, progression-free survival, and cumulative incidence of relapse, with a significant advantage associated with melphalan 200 mg/m2 in patients transplanted in less than partial response (adjusted hazard ratios for melphalan 200 mg/m2versus melphalan 140 mg/m2: 0.5, 0.54, and 0.56). In contrast, transplantation in very good partial or complete response significantly favored melphalan 140 mg/m2 for overall survival (adjusted hazard ratio: 2.02). Age, renal function, prior proteasome inhibitor treatment, gender, or Karnofsky score did not interact with overall/progression-free survival or relapse rate in the melphalan dose groups. There were no significant survival or relapse rate differences between melphalan 200 mg/m2 and melphalan 140 mg/m2 patients with high-risk or standard-risk chromosomal abnormalities. In conclusion, remission status at the time of transplantation may favor the use of melphalan 200 mg/m2 or melphalan 140 mg/m2 for key transplant outcomes (NCT01362972).

Introduction: Despite recent advances, there remains an unmet need for novel therapies to improve outcomes and abrogate the adverse effects of high-risk cytogenetics in patients with multiple myeloma (MM). In patients with triple class refractory MM in the Phase 2b STORM study, the clinical benefit of selinexor plus low dose dexamethasone (sel-dex) was preserved across high-risk cytogenetic subgroups, supporting further evaluation of selinexor combined with other anti-MM therapies (Nooka et al. ASH 2019). The phase 3 BOSTON study evaluated the combination of weekly sel-dex with the proteasome inhibitor (PI) bortezomib (SVd) against standard twice weekly bortezomib-dex (Vd) in patients with MM who had received 1-3 prior therapies. SVd significantly improved progression free survival (PFS), time to next therapy (TTNT), overall response rate (ORR) and depth of response (≥VGPR), while inducing less overall and grade ≥2 peripheral neuropathy (PN) compared with Vd. Here, we present the results of prespecified subgroup analyses from the BOSTON study according to cytogenetic risk status. Methods: In the BOSTON study, patients were randomly assigned (1:1) to once weekly oral sel (100 mg) plus once weekly subcutaneous (SC) bortezomib (1.3 mg/m2) and dex (20 mg BIW) in the SVd arm or twice weekly SC bortezomib (1.3 mg/m2) and dex (20 mg QIW) in the Vd arm. Treatment was administered in both arms until disease progression. The primary endpoint was PFS, as assessed by an Independent Review Committee (IRC). Central FISH analyses were performed on CD138+ sorted cells from bone marrow aspirates collected at screening. The high-risk group consisted of patients with at least 1 of the following abnormalities: del(17p), t(4;14), t(14;16), and amplification of 1q21 in ≥10% of screened plasma cells with amp (1q21) requiring ≥3 copies. The standard-risk group consisted of all other patients with available and known baseline cytogenetics. Results: Of the 402 enrolled patients, 192 (48%) had high-risk (SVd=97, Vd=95) and 210 (52%) had standard-risk (SVd=98, Vd=112) cytogenetics. Baseline patient and disease characteristics were well balanced across treatment arms. SVd significantly improved PFS relative to Vd in the high-risk (12.9 vs 8.1 months; HR, 0.67; 95% CI, 0.45-0.98; P=0.0192) and standard-risk (16.6 vs 9.7 months; HR, 0.63; 95% CI, 0.42-0.95; P=0.0131) groups. Time to next treatment was significantly increased with SVd in the high-risk (14.6 vs 8.7 months; P=0.0049) and standard risk groups (NR vs 13.1 months; P=0.0158). The ORR was significantly improved with SVd in the high-risk group (77.3% vs 55.8%; P=0.0008) and numerically improved in the standard-risk group (75.5% vs 67.9%; P=0.11) with comparable rates between the high-risk and standard-risk groups in the SVd arm. Very good partial response or better was achieved in 42.3% patients on SVd versus 24.2% on Vd (P=0.0041) and 46.9% on SVd versus 39.3% on Vd (P=0.13) in the high-risk and standard-risk groups, respectively. Overall survival was 23.5 months in the high-risk group in the Vd arm and was not reached in the other groups. Efficacy by specific cytogenetics abnormalities in the high-risk subgroup is shown in the table below. PFS and ORR were improved with SVd compared with Vd across all subgroups except t(14;16) which was the smallest subgroup (N=18, 4% of the study population). There were 61 deaths in the high-risk group (SVd=27 and Vd=34) versus 48 in the standard-risk group (SVd=20 and Vd=28). The safety profiles of SVd and Vd in the high-risk and standard-risk groups were consistent with the overall population. Rate of grade ≥2 peripheral neuropathy was lower with SVd compared with Vd in both the high-risk (26.8% vs 32.3%; P=0.18) and standard-risk groups (15.3% vs 36.0%; P=0.0003). Conclusions: These prespecified subgroup analyses from the BOSTON study demonstrate that despite utilizing 40% less bortezomib and 25% less dexamethasone during the first 24-weeks of treatment, SVd is superior to Vd in patients with MM including high-risk patients. The PFS benefit was particularly notable in patients with del(17p), t(4;14) and amp(1q21) abnormalities. The ORR was comparable between the high-risk and standard-risk groups in the SVd arm. These data support the use of selinexor, with its novel mechanism of action, in the treatment of patients with early relapsed MM, including those with high risk cytogenetic abnormalities. Figure 1 Disclosures Chari: Secura Bio: Consultancy; Novartis: Honoraria; Seattle Genetics: Consultancy, Research Funding; Takeda: Consultancy, Research Funding; Oncopeptides: Consultancy; Adaptive Biotechnology: Honoraria; The Binding Site: Honoraria; Bristol Myers Squibb: Consultancy; Pharmacyclics: Research Funding; Sanofi Genzyme: Consultancy; Karyopharm: Consultancy; Celgene: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Antengene: Consultancy; Amgen: Consultancy, Research Funding; Array BioPharma: Honoraria; Glaxo Smith Kline: Consultancy. Delimpasi:GENESIS: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Amgen: Consultancy, Honoraria. Spicka:Celgene, Amgen, Janssen-Cilag, Takeda, Bristol-Myers Squibb, Novartis, Sanofi: Consultancy, Honoraria, Speakers Bureau. Kryachok:Takeda, Janssen: Consultancy; Janssen, Bayer, Karyopharm, MSD, Acerta, AvbbVie, Debiopharm: Research Funding; Takeda, Janssen, Novartis, Roche, MSD, Bayer: Consultancy, Research Funding; Takeda, MSD, AbbVie, Ro: Other: Travel, accommodations, expenses. Dimopoulos:BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees, Research Funding, Speakers Bureau; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees, Research Funding, Speakers Bureau; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees, Speakers Bureau; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees, Research Funding, Speakers Bureau. Auner:Karyopharm: Consultancy, Honoraria; Amgen: Consultancy, Honoraria, Research Funding; Takeda: Consultancy, Honoraria. Leleu:Oncopeptide: Honoraria; Incyte: Honoraria; Merck: Honoraria; Carsgen: Honoraria; Amgen: Honoraria; Karyopharm: Honoraria; Sanofi: Honoraria; GSK: Honoraria; AbbVie: Honoraria; Janssen: Honoraria; BMS-celgene: Honoraria; Novartis: Honoraria. Hajek:Novartis: Consultancy, Honoraria, Research Funding; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharma MAR: Consultancy, Honoraria; BMS: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Roche: Consultancy, Honoraria, Research Funding; Oncopeptides: Consultancy, Honoraria, Research Funding. Sinha:Dr Reddys Lab, Intas Pharmaceuticals, Karyopharm Therapeutics: Honoraria. Venner:Janssen, BMS/Celgene, Sanofi, Takeda, Amgen: Honoraria; Celgene, Amgen: Research Funding. Garg:Janssen, Takeda, Celgene, Novartis, Sanofi: Honoraria. Stevens:Amgen, MorphoSys: Consultancy. Quach:GlaxoSmithKline, Karyopharm, Amgen, Celgene, Janssen Cilag: Honoraria; GlaxoSmithKline, Karyopharm, Amgen, Celgene, Janssen Cilag: Consultancy; Amgen, Celgene, karyopharm, GSK, Janssen Cilag, Sanofi.: Membership on an entity's Board of Directors or advisory committees; Amgen, sanofi, celgene, Karyopharm, GSK: Research Funding. Jagannath:Takeda: Consultancy, Honoraria; Legend Biotech: Consultancy, Honoraria; Karyopharm: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; BMS: Consultancy, Honoraria; Sanofi: Consultancy, Honoraria. Moreau:Amgen: Consultancy, Honoraria; Celgene/Bristol-Myers Squibb: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Takeda: Honoraria; Sanofi: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; Novartis: Honoraria. Levy:Bristol Meyers Squibb: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Karyopharm: Consultancy, Honoraria, Research Funding; Sanofi: Consultancy, Honoraria, Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Takeda: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Research Funding; BeiGene: Consultancy, Research Funding, Speakers Bureau; Baylor University Med Center: Current Employment; Amgen: Consultancy, Honoraria, Research Funding; AstraZeneca: Consultancy, Honoraria, Research Funding. Badros:University of Maryland: Current Employment; Amgen: Consultancy. Anderson:Amgen: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; BMS: Consultancy, Honoraria, Research Funding; GSK: Consultancy, Honoraria, Research Funding; Karyopharm: Consultancy, Honoraria, Research Funding. Bahlis:Sanofi: Consultancy, Honoraria; Karyopharm Therapeutics: Consultancy, Honoraria; Genentech: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria; GSK: Consultancy, Honoraria; BMS/Celgene and Janssen: Consultancy, Honoraria, Other: Travel, Accomodations, Research Funding; Takeda: Consultancy, Honoraria; Amgen: Consultancy, Honoraria. Facon:Celgene, Janssen, Takeda, Amgen, Roche, Karyopharm, Oncopeptides, BMS, Sanofi: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Mateos:Janssen-Cilag: Consultancy, Honoraria; Abbvie/Genentech: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Adaptive Biotechnologies: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; PharmaMar-Zeltia: Consultancy; Oncopeptides: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Regeneron: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; GlaxoSmithKline: Consultancy; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Cavo:AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel accomodations, Speakers Bureau; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; GlaxoSmithKline: Honoraria, Speakers Bureau; Karyopharm: Honoraria; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel accomodations, Speakers Bureau; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Chang:Karyopharm Therapeutics Inc: Current Employment. Landesman:Karyopharm Therapeutics Inc: Current Employment, Current equity holder in publicly-traded company. Joshi:Karyopharm Therapeutics Inc: Consultancy. Chai:Karyopharm Therapeutics Inc: Current Employment. Arazy:Karyopharm Therapeutics Inc.: Current Employment. Shah:Karyopharm Therapeutics Inc: Current Employment, Current equity holder in publicly-traded company. Shacham:Karyopharm: Current Employment, Current equity holder in publicly-traded company, Patents & Royalties: (8999996, 9079865, 9714226, PCT/US12/048319, and I574957) on hydrazide containing nuclear transport modulators and uses, and pending patents PCT/US12/048319, 499/2012, PI20102724, and 2012000928) . Kauffman:Karyopharm Therapeutics Inc: Current Employment, Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees. Richardson:Celgene/BMS, Oncopeptides, Takeda, Karyopharm: Research Funding.

Introduction: Treatment of older or frail patients (pts) with multiple myeloma (MM) remains challenging due to impaired organ function, underlying comorbidities, need for convenient regimens and burden of care, all of which impact the tolerability of anti-MM therapies. In the STORM study, selinexor plus dexamethasone (sel-dex) demonstrated anti-MM activity with an ORR of 26.2% and similar safety across all age groups in pts with triple-class refractory MM (Chari et al. NEJM 2019, Gavriatopoulou et al. IMW 2019). In the phase 3 BOSTON study, the combination of weekly sel-dex with once weekly bortezomib (SVd) was superior to standard twice weekly bortezomib and dex (Vd) across all efficacy endpoints in pts with MM who had received 1-3 prior therapies. Furthermore, while conferring a longer PFS and higher ORR than Vd, SVd was associated with significantly reduced rates of peripheral neuropathy (PN), the most clinically relevant toxicity associated with bortezomib that limits long term administration, especially in older and/or frail pts. Here we present results of subgroup analyses of the BOSTON study to evaluate the safety and efficacy of SVd versus Vd based on age and frailty index. Methods: Pts enrolled in BOSTON were assigned (1:1) to once weekly oral sel (100 mg) plus once weekly subcutaneous (SC) bortezomib (1.3 mg/m2) and dex (20 mg BIW) in the SVd arm or to standard twice weekly SC bortezomib (1.3 mg/m2) and dex (20 mg QIW) in the Vd arm. Treatment was administered in both arms until disease progression. The primary endpoint was PFS, as assessed by an Independent Review Committee. For these analyses, pts were assigned to 2 groups based on age ( Results: Of the 402 enrolled pts, 241 (60%) were ≥65 years (SVd=109, Vd=132). Of these, 81 (37%) were ≥75 and 106 (44%) were categorized as frail (SVd=51, Vd=55). Baseline pt and disease characteristics were well balanced between treatment arms in the subgroups. PFS was prolonged in both age groups with SVd compared with Vd. In ≥65, PFS was 21.0 vs 9.5 months (HR, 0.55; 95% CI, 0.37-0.83; P=0.0018) and in Conclusions: In pts with previously treated MM, the once weekly SVd regimen led to prolonged PFS, improved response rates and rates of PN regardless of age and frailty score compared to standard twice weekly Vd. Non-PN AEs were higher with triplet than doublet therapy, but most of the AEs were reversible and treatable. There were fewer deaths on SVd in pts ≥65 and in frail pts compared to Vd. Once weekly SVd is a potent and convenient treatment option for pts with previously treated MM, including those who are ≥65 years and/or frail. Figure Disclosures Auner: Karyopharm: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Amgen: Consultancy, Honoraria, Research Funding. Gavriatopoulou:Amgen: Consultancy, Honoraria; Karyopharm: Consultancy, Honoraria; Genesis Pharma: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Takeda: Consultancy, Honoraria. Delimpasi:GENESIS: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Amgen: Consultancy, Honoraria. Spicka:Celgene, Amgen, Janssen-Cilag, Takeda, Bristol-Myers Squibb, Novartis, Sanofi: Consultancy, Honoraria, Speakers Bureau. Dimopoulos:BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees, Research Funding, Speakers Bureau; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees, Research Funding, Speakers Bureau; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees, Speakers Bureau; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees, Research Funding, Speakers Bureau. Leleu:Incyte: Honoraria; Merck: Honoraria; AbbVie: Honoraria; Carsgen: Honoraria; Janssen: Honoraria; Novartis: Honoraria; BMS-celgene: Honoraria; Amgen: Honoraria; GSK: Honoraria; Sanofi: Honoraria; Karyopharm: Honoraria; Oncopeptide: Honoraria. Hajek:Celgene: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Research Funding; BMS: Consultancy, Honoraria, Research Funding; Pharma MAR: Consultancy, Honoraria; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Roche: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Oncopeptides: Consultancy, Honoraria, Research Funding. Sinha:Dr Reddys Lab, Intas Pharmaceuticals, Karyopharm Therapeutics: Honoraria. Venner:Janssen, BMS/Celgene, Sanofi, Takeda, Amgen: Honoraria; Celgene, Amgen: Research Funding. Garg:Janssen, Takeda, Celgene, Novartis, Sanofi: Honoraria. Stevens:Amgen, MorphoSys: Consultancy. Quach:Amgen, Celgene, karyopharm, GSK, Janssen Cilag, Sanofi.: Membership on an entity's Board of Directors or advisory committees; GlaxoSmithKline, Karyopharm, Amgen, Celgene, Janssen Cilag: Honoraria; Amgen, sanofi, celgene, Karyopharm, GSK: Research Funding; GlaxoSmithKline, Karyopharm, Amgen, Celgene, Janssen Cilag: Consultancy. Jagannath:Sanofi: Consultancy, Honoraria; Legend Biotech: Consultancy, Honoraria; Karyopharm: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; BMS: Consultancy, Honoraria. Moreau:Sanofi: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Takeda: Honoraria; Abbvie: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Celgene/Bristol-Myers Squibb: Consultancy, Honoraria; Novartis: Honoraria. Levy:Takeda: Consultancy, Honoraria, Research Funding; Sanofi: Consultancy, Honoraria, Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Karyopharm: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Bristol Meyers Squibb: Consultancy, Honoraria, Research Funding; AstraZeneca: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Research Funding; BeiGene: Consultancy, Research Funding, Speakers Bureau; Baylor University Med Center: Current Employment. Badros:Amgen: Consultancy; University of Maryland: Current Employment. Anderson:BMS: Consultancy, Honoraria, Research Funding; Karyopharm: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; GSK: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Research Funding. Bahlis:BMS/Celgene and Janssen: Consultancy, Honoraria, Other: Travel, Accomodations, Research Funding; Takeda: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Genentech: Consultancy, Honoraria; GSK: Consultancy, Honoraria; Karyopharm Therapeutics: Consultancy, Honoraria; Sanofi: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria. Facon:Celgene, Janssen, Takeda, Amgen, Roche, Karyopharm, Oncopeptides, BMS, Sanofi: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Mateos:EDO Mundipharma: Honoraria; Seattle Genetics: Honoraria; Abbvie: Honoraria; Janssen: Honoraria; Bristol-Myers Squibb: Honoraria; Amgen: Honoraria; GlaxoSmithKline: Honoraria; Adaptive Biotechnologies: Honoraria; Takeda: Honoraria; Roche: Honoraria. Cavo:Jannsen, BMS, Celgene, Sanofi, GlaxoSmithKline, Takeda, Amgen, Oncopeptides, AbbVie, Karyopharm, Adaptive: Consultancy, Honoraria. Joshi:Karyopharm Therapeutics Inc: Consultancy. Chai:Karyopharm Therapeutics Inc: Current Employment. Arazy:Karyopharm Therapeutics Inc.: Current Employment. Shah:Karyopharm Therapeutics Inc: Current Employment, Current equity holder in publicly-traded company. Shacham:Karyopharm: Current Employment, Current equity holder in publicly-traded company, Patents & Royalties: (8999996, 9079865, 9714226, PCT/US12/048319, and I574957) on hydrazide containing nuclear transport modulators and uses, and pending patents PCT/US12/048319, 499/2012, PI20102724, and 2012000928) . Kauffman:Karyopharm Therapeutics Inc: Current Employment, Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees. Richardson:Celgene/BMS, Oncopeptides, Takeda, Karyopharm: Research Funding.

8024 Background: Lenalidomide (LEN) is typically a frontline therapy for newly diagnosed MM. Patients (pts) with MM refractory to LEN are less likely to repond to other IMiDs and represent a signification area of unmet medical need. In the BOSTON study in the ITT population, XVd was associated with significant improvements in median progression-free survival (PFS), overall response rate (ORR), and rates of peripheral neuropathy, with trends in overall survival (OS) favoring XVd. Methods: The BOSTON trial (NCT03110562) is a Phase 3 randomized, controlled, open-label study of once weekly XVd vs twice weekly Vd in pts with MM and 1-3 prior therapies. We performed post-hoc analyses on two different subgroups to compare outcomes based on refractory status to LEN and immunomodulatory drug (IMiD) therapy. These post hoc analyses evaluated if PFS, overall response rate (ORR), time to next treatment (TTNT) and safety was influenced by prior treatment with LEN when comparing XVd with Vd. Results: Amongst the 402 pts in BOSTON, 160 had MM refractory to any IMiD (XVd = 74, Vd = 86). Of those, 106 were documented to be refractory to LEN (XVd = 53, Vd = 53) and 296 were not refractory to LEN (XVd = 142, Vd = 154). Baseline characteristics were generally well balanced between subgroups. In these subgroups based on refractory status to IMiD or LEN, median PFS was significantly longer in the XVd arm as compared to Vd (IMiD refractory, 13.9 vs. 8.4 months (mo), p = 0.005; LEN refractory, 10.2 vs. 7.1 mo, p = 0.012; not LEN refractory, 15.4 vs 9.6 mo, p = 0.014). Significant increases in TTNT were observed with XVd treatment in pts that were IMiD refractory (14.8 vs. 10.2 mo, p = 0.003), LEN refractory (13.0 vs. 7.6 mo, p = 0.015), and not refractory to LEN (19.1 vs 12.9 mo, p = 0.005). ORR was improved with XVd compared to Vd regardless of refractory status (IMiD refractory, 68.9% vs 55.8%, p = 0.045; LEN refractory, 67.9% vs. 47.2%, p = 0.016; and not refractory to LEN, 79.6% vs 67.5%, p = 0.010). The most common treatment-emergent AEs for the XVd/Vd arms for all subgroups were thrombocytopenia (66.2/30.6%; 71.7/40.4%; 55.6/22.4%), nausea (48.6/11.8%; 50.9/11.5%; 50.0/9.2%), and fatigue (40.5/20.0%; 45.3/21.2%; 40.8/17.1%) for IMiD, LEN, and not LEN refractory, respectively. Incidence of PN AEs of any grade were reduced compared to pts treated with Vd (IMiD refractory, 27% vs. 42.4%; LEN refractory, 30.2% vs 36.5%; not refractory, LEN 33.1% vs 50.7%). Conclusions: In pts with previously treated MM, PFS, ORR, and TTNT were significantly improved regardless of documented refractory status to any IMiD or to LEN-specifically. These analyses support the use of the XVd combination for pts with disease refractory to LEN and likely to any IMiD. Clinical trial information: NCT03110562.

8019 Background: Multiple myeloma (MM) typically affects older populations, which are more vulnerable to toxicity with anti-MM treatments. These patients (pts) have significant morbidity and mortality, resulting in a need for dose modifications or alternative suboptimal treatment options. Significant improvements were observed in the BOSTON study with XVd vs Vd in median progression-free survival (PFS), overall response rate (ORR), and rates of peripheral neuropathy (PN); median overall survival (OS) trended in favor of XVd. Methods: The phase 3 randomized BOSTON trial (NCT03110562) is a controlled, open-label study of once weekly XVd vs. twice weekly standard Vd in pts with MM and 1-3 prior treatment regimens. We performed post-hoc analyses to compare survival benefits in pts ≥65 vs < 65 years of age. Results: The BOSTON study enrolled a total of 402 pts between June 2017 and February 2019 that were randomized into XVd or Vd arms. The numbers of pts treated with XVd or Vd who were ≥65 were 109/132 and 86/75 who were < 65, respectively. Baseline characteristics were similar by age although pts ≥65 years were less likely to have received ASCT than those < 65 years (48.4% vs. 25.3%). Median PFS was prolonged with XVd compared with Vd, across both age groups: ≥65 (HR, 0.55 [95% CI, 0.37-0.83] P = 0.002) and < 65, (HR, 0. 74 [95% CI, 0.49-1.11], P = 0.07). Vd was associated with a lower ORR (64.4%) than treatment with XVd (76.1%) (OR, 1.77 [95% CI, 1.00-3.11], P = 0.024) in pts ≥65, while the ORR in those < 65 was 76.7% with XVd and 58.7% (OR, 2.33 [95% CI, 1.18-4.59], P = 0.007) with Vd. As of Jan 2021, the median OS for the overall population was not reached for both arms (HR = 0.86; p = 0.193), with 61 and 75 deaths in the XVd and Vd arms, respectively. Median OS was not reached in pts ≥65 with XVd and was 28.6 months with Vd (HR = 0.60; 95% CI, 0.38-0.94; p = 0.012), while there was no difference in the OS for pts < 65 (HR = 1.52; 95% CI, 0.86-2.68; p = 0.926). Pts ≥65 had a lower incidence of death with XVd as compared to Vd (29 vs 56) and there were 32 deaths with XVd and 19 with Vd in pts < 65. Grade ≥3 treatment-emergent adverse events were not observed more often in older compared to younger pts. Amongst pts ≥65, PN of any grade was lower with XVd (32.1%) compared to Vd (46.5%); (OR 0.57 [95% CI 0.34-0.97], p = 0.017), including a lower incidence of grade ≥3 PN (XVd 4.6% vs. Vd 11.6%). Pts < 65 followed a similar trend of PN AEs of any grade: XVd, 32.6%; Vd, 48.0% (OR 0.42 [95% CI 0.21-0.82], p = 0.006). Conclusions: In an older patient population with a poor prognosis, XVd was associated with a significant survival benefit, improved PFS and OR with reduced PN, and requires relatively short and infrequent clinic visits. XVd may be a simple, effective regimen for pts ≥65 years of age. Clinical trial information: NCT03110562.

The original version of this Article contained an error in the author affiliations. The affiliation of Marjan Enayati with ‘Ludwig Boltzmann Cluster for Cardiovascular Research at the Center for Biomedical Research, Medical University of Vienna, Austria' was inadvertently omitted. This has now been corrected in both the PDF and HTML versions of the Article.

The European Society for Blood and Marrow Transplantation Chronic Malignancies Working Party held a preceptorship meeting in Turin, Italy on 25-26 September 2014, to discuss the role of stem cell transplantation (SCT) in the treatment of multiple myeloma and other plasma cell disorders. Scientists and clinicians working in the field gathered to discuss a variety of topics including the results of recent clinical trials, basic research, the concept of minimal residual disease, and immune modulation. As individual presentations revealed, important advances have occurred in our understanding of the pathophysiology of myeloma and the role that SCT, along with other forms of immunotherapy, plays in treating it. Each presentation stimulated discussion and exchange of ideas among the attendants. We decided to summarize and, importantly, to update the meeting proceedings in this review to share stimulating discussions and ideas on potentially novel treatment strategies among clinicians.