Second Line Therapy in Multiple Myeloma: A SEER Medicare Analysis.

INTRODUCTION: The therapeutic landscape in relapsed/refractory multiple myeloma (RRMM) has changed rapidly, with twenty-two drug approvals since 2012. We characterized population-level trends in RRMM therapy selection, survival and cost outcomes associated with RRMM treatment over time. MATERIALS AND METHODS: Our cohort included adults diagnosed with multiple myeloma (MM) in the SEER-Medicare database from 2007-2017 who received at least one antimyeloma agent. MM-directed therapies and lines of therapy were identified. Changes in 2LT regimens over time were described. Trends in overall survival from 2LT initiation over time were analyzed using a Cox proportional hazards model adjusting for factors associated with survival in MM. Trends in mean inflation-adjusted cost per 12 months of 2LT were analyzed using JoinPoint analysis. RESULTS: A total of 9,822 patients met eligibility criteria, of whom 5,866 (59.7%) received 2LT. By 2018, 46% of 2LT regimens contained at least one agent approved in 2012 or later. Year of 2LT initiation was associated with improved overall survival (HR 0.78 per 5 years, 95% CI 0.74-0.84) after adjustment. Costs associated with 2LT increased over the study period, and the rate of cost increase increased significantly after 2012 (0.89%/year vs. 9.9%/year, P < .001), with higher total costs for regimens containing newer novel agents (mean $224,193 vs. $189,381, P < .001) CONCLUSION: Overall survival after initiation of 2LT has improved, however this has been accompanied by significant increases in costs of RRMM treatment, particularly for patients receiving newer novel agents. These findings provide useful context for existing and future drug approvals in RRMM.

Geriatric assessment-guided interventions for older adults with multiple myeloma: A feasibility and acceptability study.

INTRODUCTION: Geriatric assessment (GA)-guided supportive care programs have been successful in improving treatment outcomes for older adults with solid-organ cancers. This study aimed to evaluate the feasibility of a GA-guided supportive care program among older adults treated for multiple myeloma (MM). MATERIALS AND METHODS: The study utilized an existing registry of adults with plasma cell disorders at the University of North Carolina. Patients with MM, aged 60 or older, and having a GA-identified deficit in one or more problem area were offered referrals to supportive care resources during routine visits. Problem areas included physical function deficits, polypharmacy, and anxiety or depression. Patients with physical function deficits were offered referral to physical therapy (PT), those with polypharmacy to an Oncology Clinical Pharmacist Practitioner (CPP), and those with mental health symptoms to the Comprehensive Cancer Support Program (CCSP). RESULTS: Of the 58 individuals identified as having at least one deficit on the GA, PT was the most commonly identified relevant resource (79%), followed by CPP visits (57%). Among individuals that were offered referral(s) to at least one new supportive care resource, the acceptance rate was 50%. Referral acceptance rates were highest among those recommended for a CPP visit (55% of those approached) and lowest for CCSP (0%). DISCUSSION: The study examined the feasibility and acceptability of a referral program for supportive care resources among older adults with MM who have deficits on GA. The most commonly identified deficit was physical functioning, followed by polypharmacy and mental health. The study found that physical interventions and referrals to CPPs were the most accepted interventions. However, the low proportion of patients who accepted physical therapy referrals indicates the need for tailored and more personalized approaches. Further research is needed to explore the feasibility and impact of supportive care referral programs for older adults with MM.

Using a Modified Delphi Panel to Estimate Health Service Utilization for Patients with Advanced and Non-Advanced Systemic Light Chain Amyloidosis.

Purpose: Patients with diagnosed with systemic light chain (AL) amyloidosis at advanced Mayo stages have greater morbidity and mortality than those diagnosed at non-advanced stages. Estimating service use by severity is difficult because Mayo stage is not available in many secondary databases. We used an expert panel to estimate healthcare utilization among advanced and non-advanced AL amyloidosis patients. Patients and Methods: Using the RAND/UCLA modified Delphi method, expert panelists completed 180 healthcare utilization estimates, consisting of inpatient and outpatient visits, testing, chemotherapy, and procedures by disease severity and organ involvement during two treatment phases (the 1 year after starting first line [1L] therapy and 1 year following treatment [post-1L]). Estimates were also provided for post-1L by hematologic treatment response (complete or very good partial response [CR/VGPR], partial, no response or relapse [PR/NR/R]). Areas of disagreement were discussed during a meeting, after which ratings were completed a second time. Results: During 1L therapy, 55% of advanced patients had ≥1 hospitalization and 38% had ≥2 admissions. Rates of hematopoietic stem cell transplant (HSCT) in advanced patients were 5%, while pacemaker or implantable cardioverter defibrillator (ICD) placement were 15%. During post-1L therapy, rates of hospitalization in advanced patients remained high (≥1 hospitalization: 20-43%, ≥2 hospitalizations: 10-20%), and up to 10% of advanced patients had a HSCT. Ten percent of these patients underwent pacemaker/ICD placement. Conclusion: Experts estimated advanced patients, who would not be good candidates for HSCT, would have high rates of hospitalization (traditionally the most expensive type of healthcare utilization) and other health service use. The development of new treatment options that can facilitate organ recovery and improve function may lead to decreased utilization.

Selinexor-Based Triplet Regimens in Patients With Multiple Myeloma Previously Treated With Anti-CD38 Monoclonal Antibodies.

BACKGROUND: The increasing use of anti-CD38 monoclonal antibodies (αCD38 mAbs) for newly diagnosed or early relapsed multiple myeloma (MM), especially in non-transplant eligible patients, may lead to more patients developing αCD38 mAb-refractory disease earlier in the treatment course with fewer treatment options. PATIENTS AND METHODS: We analyzed the efficacy and safety of selinexor-based triplets (selinexor+dexamethasone [Sd] plus pomalidomide [SPd, n = 23], bortezomib [SVd, n = 16] or carfilzomib (SKd, n = 23]) in a subset of STOMP (NCT02343042) and BOSTON (NCT03110562) study patients treated previously with αCD38 mAbs. RESULTS: Sixty-two patients (median 4 prior therapies, range 1 to 11, 90.3% refractory to αCD38 mAb) were included. Overall response rates (ORR) in the SPd, SVd and SKd cohorts were 52.2%, 56.3%, and 65.2%, respectively. Overall response rate was 47.4% among patients who had MM refractory to the third drug reintroduced in the Sd-based triplet. Median progression-free survival in the SPd, SVd, and SKd cohorts was 8.7, 6.7, and 15.0 months, respectively, and median overall survival was 9.6, 16.9, and 33.0 months, respectively. Median time to discontinuation in the SPd, SVd, and SKd cohorts was 4.4, 5.9, and 10.6 months, respectively. The most common hematological adverse events were thrombocytopenia, anemia, and neutropenia. Nausea, fatigue, and diarrhea were primarily grade 1/2. Adverse events were generally manageable with standard supportive care and dose modifications. CONCLUSION: Selinexor-based regimens may offer effective and well-tolerated therapy to patients with relapsed and/or refractory MM who had disease previously exposed or refractory to αCD38 mAb therapy and could help address the unmet clinical need in these high-risk patients.

Phase I study of opaganib, an oral sphingosine kinase 2-specific inhibitor, in relapsed and/or refractory multiple myeloma.

Multiple myeloma (MM) remains an incurable disease and there is an unmet medical need for novel therapeutic drugs that do not share similar mechanisms of action with currently available agents. Sphingosine kinase 2 (SK2) is an innovative molecular target for anticancer therapy. We previously reported that treatment with SK2 inhibitor opaganib inhibited myeloma tumor growth in vitro and in vivo in a mouse xenograft model. In the current study, we performed a phase I study of opaganib in patients with relapsed/refractory multiple myeloma (RRMM). Thirteen patients with RRMM previously treated with immunomodulatory agents and proteasome inhibitors were enrolled and treated with single-agent opaganib at three oral dosing regimens (250 mg BID, 500 mg BID, or 750 mg BID, 28 days as a cycle). Safety and maximal tolerated dose (MTD) were determined. Pharmacokinetics, pharmacodynamics, and correlative studies were also performed. Opaganib was well tolerated up to a dose of 750 mg BID. The most common possibly related adverse event (AE) was decreased neutrophil counts. There were no serious AEs considered to be related to opaganib. MTD was determined as at least 750 mg BID. On an intent-to-treat basis, one patient (7.7%) in the 500 mg BID dose cohort showed a very good partial response, and one other patient (7.7%) achieved stable disease for 3 months. SK2 is an innovative molecular target for antimyeloma therapy. The first-in-class SK2 inhibitor opaganib is generally safe for administration to RRMM patients, and has potential therapeutic activity in these patients. Clinicaltrials.gov: NCT02757326.

Cross-Sectional Analysis of Clinical Trial Availability and North Carolina Neighborhood Social Vulnerability.

PURPOSE: Residents of communities facing social vulnerability (eg, poverty) have limited access to clinical trials, leaving them susceptible to experiencing poor health outcomes. We examined the association between North Carolina county-level social vulnerability and available multiple myeloma (MM) trials. METHODS: Using a novel data linkage between ClinicalTrials.gov, the 2019 American Community Survey, and the Centers for Disease Control and Prevention's Social Vulnerability Index, we investigated at the county level (1) availability of MM trial sites and (2) the relationship between Social Vulnerability Index and MM trial site availability using logistic regression. RESULTS: Between 2002 and 2021, 229 trials were registered across 462 nonunique trial sites in 34 counties. Nearly 50% of trial sites were in academic medical centers, 80% (n = 372) of all trials were industry-sponsored, 60% (n = 274) were early-phase, and 50% (n = 232) were for patients with relapsed or refractory MM. Counties with low as opposed to high poverty rates had six times greater odds of having ≥ 1 MM trial sites (odds ratio [OR], 5.60; 95% CI, 1.85 to 19.64; P = .004). Counties with the lowest percentage of Black Indigenous Persons of Color and non-native English speakers had 77% lower odds (OR, 0.23; 95% CI, 0.07 to 0.69; P = .011) of having ≥ 1 trial sites. The effect remained significant after accounting for the presence of five academic medical centers (n = 95; OR, 0.18; 95% CI, 0.05 to 0.6; P = .008) and adjustment for metropolitan, suburban, or rural status (OR, 0.25; 95% CI, 0.07 to 0.81; P = .025). CONCLUSION: Counties with the lowest poverty rates had more MM trial sites, whereas those with the lowest percentage of Black Indigenous Persons of Color populations had fewer MM trial sites. Multilevel efforts are needed to improve the availability and access to trials for socially vulnerable populations.

Selinexor-based regimens in patients with multiple myeloma after prior anti-B-cell maturation antigen treatment.

There is a lack of consensus on therapy sequencing in previously treated multiple myeloma, particularly after anti-B-cell maturation antigen (BCMA) therapy. Earlier reports on selinexor (X) regimens demonstrated considerable efficacy in early treatment, and after anti-BCMA-targeted chimeric antigen receptor-T cell therapy. Here, we present data from 11 heavily pretreated patients who predominantly received BCMA-antibody-drug conjugate therapy. We observe that X-containing regimens are potent and achieve durable responses with numerically higher overall response and clinical benefit rates, as well as median progression free survival compared to patients' prior anti-BCMA therapies, despite being used later in the treatment course. In an area of evolving unmet need, these data reaffirm the efficacy of X-based regimens following broader anti-BCMA therapy.

Longitudinal Analysis of Patient-Reported Cognitive Function in Multiple Myeloma.

BACKGROUND: Cancer-related cognitive impairment (CRCI) has been largely unstudied in patients with multiple myeloma (MM). This study describes patient-reported cognition over time and patient factors associated with adverse cognitive outcomes in MM. METHODS: Participants enrolled in a registry in which they completed a geriatric assessment at study entry, and 3 & 6 months after entry. Cognitive function was assessed using the EORTC QLQ-C30 Cognitive Function subscale, with CRCI defined as scores < 75. Generalized estimating equation (GEE) models were used to fit longitudinal models to investigate differences by group and differences in changes over time by group, with adjustment for time since diagnosis. RESULTS: One hundred and four adults with MM had mean age of 67 years and 30% identified as Black. Patient-reported CRCI was present in 18% of participants at enrollment, 21% at 3 months, and 30% at 6 months. Worse cognitive function was reported in those with impairments in physical function (P = .002), IADLs (P = .02), and performance status (P = .04), as well as in those who were prefrail/frail (P = .02) and depressed (P = .049). Greater cognitive decline over time was observed in patients without CRCI at enrollment (P < .0001) and those with lower levels of education (P = .04). CONCLUSION: This is one of the first studies to describe longitudinal changes in patient-reported cognition in patients with MM. Several potentially intervenable factors, including physical function impairment and depression, were associated with worse cognition at study entry, but only baseline CRCI status and education level were predictive of future decline.

Supportive Care and Symptom Management for Patients With Immunoglobulin Light Chain (AL) Amyloidosis.

Immunoglobulin light chain (AL) amyloidosis is a disorder of clonal plasma cells characterized by deposition of amyloid fibrils in a variety of tissues, leading to end-organ injury. Renal or cardiac involvement is most common, though any organ outside the central nervous system can develop amyloid deposition, and symptomatic presentations may consequently vary. The variability and subtlety of initial clinical presentations may contribute to delayed diagnoses, and organ involvement is often quite advanced and symptomatic by the time a diagnosis is established. Additionally, while organ function can improve with plasma-cell-directed therapy, such improvement lags behind hematologic response. Consequently, highly effective supportive care, including symptom management, is essential to improve quality of life and to maximize both tolerance of therapy and likelihood of survival. Considering the systemic nature of the disease, close collaboration between clinicians is essential for effective management.

Physical Function, Psychosocial Status, and Symptom Burden Among Adults with Plasma Cell Disorders and Associations with Quality of Life.

BACKGROUND: The plasma cell disorders (PCDs), multiple myeloma (MM), and light-chain amyloidosis (AL) are disproportionately diseases of older adults, whose care may be complicated by frailty associated with advancing age. We sought to evaluate the prevalence of functional deficits and symptoms in a cohort of persons with PCDs and associations of demographic, disease-related, functional, and psychosocial measures with quality of life (QoL). PATIENTS AND METHODS: Adults with PCDs were recruited into an observational registry in 2018-2020. Patients completed a functional assessment and European Organization for Research and Treatment of Cancer QoL questionnaire (QLQ-C30). Associations of covariates of interest with QoL were evaluated via univariate linear regression. RESULTS: Among 121 adults, the mean age was 68.6. Diagnoses were 74% MM, 14% AL, 7% both MM and AL, and 5% other PCDs. The median time from diagnosis was 34.9 months. Median lines of therapy were 2, with 11% having received ≥4th-line therapy.Patients with functional deficits had lower mean QoL scores: dependence in IADLs (66.3 vs. 79.9, P = .001) and recent falls (56.7 vs. 76.8, P = .001). Patients ≤6 months from diagnosis had lower QoL (66.7) than those ≥2 years from diagnosis (77.3, P = .03). However, patients on later lines of therapy (≥4th-line) had lower QoL (62.2) than those on 1st-line treatment (76.0, P = .04). CONCLUSIONS: Patients with physical impairments and more advanced PCDs had lower QoL than those without deficits or earlier in their disease course. Early identification of physical impairments may facilitate interventions that mitigate these deficits and thereby improve QoL for patients with PCDs.

Prevalence and clinical correlates of cognitive impairment in adults with plasma cell disorders.

INTRODUCTION: Older adults with plasma cell disorders (PCDs) experience cognitive dysfunction that may be attributable to the disease and associated therapies. Yet, this has seldom been reported in the literature. Our objectives were to describe cognitive function (objective and patient-reported) in adults with PCDs and to explore clinical correlates of cognitive impairment. MATERIALS AND METHODS: Participants completed a geriatric assessment between March 2018 and February 2020. Cognitive function was evaluated using two objective measures - Montreal Cognitive Assessment (MoCA, cutpoint <26) and Blessed Orientation Memory Concentration Test (BOMC, cutpoint >4) - and two patient-reported outcome (PRO) measures - Patient-Reported Outcomes Measurement Information System Cognitive Function (PROMIS-CF, cutpoint <45) and European Organization for Research and Treatment of Cancer Cognitive Functioning subscale (EORTC-CF, cutpoint <75). Spearman correlations examined relationships among these measures and log binomial regression was used to examine characteristics associated with cognitive impairment, as defined by the MoCA and PROMIS-CF measures. RESULTS: Among 86 participants with a mean age of 69 (range: 46-91), the prevalence of cognitive dysfunction was between 20% (BOMC) and 63% (MoCA). There was moderate correlation among objective measures (r = 0.51, p < 0.0001), moderate to high correlation among PRO measures (r = 0.69, p < 0.0001), but no correlation between objective and PRO measures. Factors associated with objective impairment included ≤ high school education (RR 1.46, p = 0.009), living alone (RR 1.42, p = 0.02), relapsed/refractory disease (RR 1.39, p = 0.04), empirically de-intensified induction therapy (RR 1.62, p = 0.008), frailty (RR 1.49, p = 0.04), and peripheral vascular disease (RR 1.54, p = 0.002). Factors associated with PRO impairment included social isolation (RR 3.43, p = 0.003), depression (RR 3.30, p = 0.004) and anxiety (RR 4.43, p = 0.0002), frailty (RR 3.60, p = 0.02), falls in the previous 6 months (RR 2.53, p = 0.02), and deficits in physical function (RR 4.44, p = 0.01). Older age was not associated with either objective or PRO impairment. DISCUSSION: Cognitive impairment, using objective and PRO screening measures, was relatively common in adults with PCDs. Cancer-related factors and medical comorbidities were associated with objective cognitive impairment whereas psychosocial and functional factors were associated with PRO impairment.

Epstein-Barr virus mucocutaneous ulcer followed by Hodgkin lymphoma in multiple myeloma patient.

Epstein-Barr virus mucocutaneous ulcers (EBV MCU) are B-cell lymphoproliferative disorders associated with immunosuppression. We report EBV MCU in a multiple myeloma patient on lenalidomide maintenance after stem cell transplant that resolved with decreased immunosuppression. Furthermore, the subsequent development of classical Hodgkin lymphoma suggests an underlying predisposition to EBV-driven lymphoproliferative disorders.

Geriatric-assessment-identified functional deficits among adults with multiple myeloma with normal performance status.

OBJECTIVES: Findings from a brief geriatric assessment (GA) in a cohort of adults with multiple myeloma (MM) are presented, with particular attention to the utility of the GA in identifying important deficits in adults judged to have a normal Karnofsky Performance Status (KPS ≥ 80). MATERIALS AND METHODS: Adults age 18 and older with MM were recruited into an observational study from 2018 to 2020. A modified Cancer and Aging Research Group (CARG) GA was administered at enrollment. Enrollees also completed the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life of Cancer Patients Core 30 questionnaire (QLQ-C30), with subscales of physical, social, role, and cognitive functioning (range 0-100; higher values indicate better function). Data were analyzed using descriptive statistics for the full cohort and stratified by concurrent KPS (score < 80 vs ≥ 80). RESULTS: Among 89 adults, the mean age was 69.1 years, 68% were aged ≥65 years, and 70% were white. In this cohort, 78% had KPS ≥ 80. Among those with KPS ≥ 80, functional impairments (Timed Up and Go ≥14 s and dependence in ≥1 instrumental activity of daily living) were seen in 30% and 21%, respectively, with 11% reporting ≥1 fall in the prior 6 months. At least two GA-identified deficits were detected in 50% of the overall cohort and in 41% of those with KPS ≥ 80. Among those with KPS ≥ 80, self-reported physical impairment on EORTC QLQ-C30 was noted by 34%. CONCLUSION: Using a modified CARG GA and EORTC questionnaire, functional impairments were identified among adults considered to have a good performance status based on a KPS (≥ 80). Future studies should focus on using GA measures for therapy assignment and identifying opportunities for intervening upon GA-identified deficits.

Once weekly selinexor, carfilzomib and dexamethasone in carfilzomib non-refractory multiple myeloma patients.

BACKGROUND: Proteasome inhibitors (PIs), including carfilzomib, potentiate the activity of selinexor, a novel, first-in-class, oral selective inhibitor of nuclear export (SINE) compound, in preclinical models of multiple myeloma (MM). METHODS: The safety, efficacy, maximum-tolerated dose (MTD) and recommended phase 2 dose (RP2D) of selinexor (80 or 100 mg) + carfilzomib (56 or 70 mg/m2) + dexamethasone (40 mg) (XKd) once weekly (QW) was evaluated in patients with relapsed refractory MM (RRMM) not refractory to carfilzomib. RESULTS: Thirty-two patients, median prior therapies 4 (range, 1-8), were enrolled. MM was triple-class refractory in 38% of patients and 53% of patients had high-risk cytogenetics del(17p), t(4;14), t(14;16) and/or gain 1q. Common treatment-related adverse events (all/Grade 3) were thrombocytopenia 72%/47% (G3 and G4), nausea 72%/6%, anaemia 53%/19% and fatigue 53%/9%, all expected and manageable with supportive care and dose modifications. MTD and RP2D were identified as selinexor 80 mg, carfilzomib 56 mg/m2, and dexamethasone 40 mg, all QW. The overall response rate was 78% including 14 (44%) ≥ very good partial responses. Median progression-free survival was 15 months. CONCLUSIONS: Weekly XKd is highly effective and well-tolerated. These data support further investigation of XKd in patients with MM.

Primary plasma cell leukemia: consensus definition by the International Myeloma Working Group according to peripheral blood plasma cell percentage.

Primary plasma cell leukemia (PCL) has a consistently ominous prognosis, even after progress in the last decades. PCL deserves a prompt identification to start the most effective treatment for this ultra-high-risk disease. The aim of this position paper is to revisit the diagnosis of PCL according to the presence of circulating plasma cells in patients otherwise meeting diagnostic criteria of multiple myeloma. We could identify two retrospective series where the question about what number of circulating plasma cells in peripheral blood should be used for defining PCL. The presence of ≥5% circulating plasma cells in patients with MM had a similar adverse prognostic impact as the previously defined PCL. Therefore, PCL should be defined by the presence of 5% or more circulating plasma cells in peripheral blood smears in patients otherwise diagnosed with symptomatic multiple myeloma.

A phase I/II study of ixazomib, pomalidomide, and dexamethasone for lenalidomide and proteasome inhibitor refractory multiple myeloma (Alliance A061202).

Preclinical studies have demonstrated activity of the oral proteasome inhibitor (PI) ixazomib (IXA) in bortezomib-resistant multiple myeloma (MM) and synergy with immunomodulatory drugs. We therefore conducted a phase I/II study to establish the safety and preliminary efficacy of IXA with pomalidomide (POM) and dexamethasone (DEX) in lenalidomide (LEN)/PI-refractory MM. Dose escalation established a 4 mg dose of POM and IXA and 20/40 mg dose of DEX as the maximum tolerated dose. The phase II portion of the trial was redesigned and started anew after six patients had been randomized to IXA-POM-DEX due to a rapidly changing treatment landscape. Among the 29 evaluable LEN/PI-refractory patients treated with IXA-POM-DEX in phase I/II, the overall response rate (partial response or better) was 51.7% with a median duration of response of 16.8 months (range 56 days to 4.1 years), median progression-free survival of 4.4 months (95% confidence interval [CI]: 3.0-18.4), and median overall survival of 34.3 months (95% CI: 19.2 to not reached). Hematologic, gastrointestinal, and constitutional adverse events were common and consistent with the side-effect profiles of the individual agents. Our results support further evaluation of this all-oral regimen in relapsed/refractory MM.

Quality of life analyses in patients with multiple myeloma: results from the Selinexor (KPT-330) Treatment of Refractory Myeloma (STORM) phase 2b study.

BACKGROUND: Selinexor is an oral, selective nuclear export inhibitor. STORM was a phase 2b, single-arm, open-label, multicenter trial of selinexor with low dose dexamethasone in patients with penta-exposed relapsed/refractory multiple myeloma (RRMM) that met its primary endpoint, with overall response of 26% (95% confidence interval [CI], 19 to 35%). Health-related quality of life (HRQoL) was a secondary endpoint measured using the Functional Assessment of Cancer Therapy - Multiple Myeloma (FACT-MM). This study examines impact of selinexor treatment on HRQoL of patients treated in STORM and reports two approaches to calculate minimal clinically important differences for the FACT-MM. METHODS: FACT-MM data were collected at baseline, on day 1 of each 4-week treatment cycle, and at end of treatment (EOT). Changes from baseline were analyzed for the FACT-MM total score, FACT-trial outcome index (TOI), FACT-General (FACT-G), and the MM-specific domain using mixed-effects regression models. Two approaches for evaluating minimal clinically important differences were explored: the first defined as 10% of the instrument range, and the second based on estimated mean baseline differences between Eastern Cooperative Oncology Group performance status (ECOG PS) scores. Post-hoc difference analysis compared change in scores from baseline to EOT for treatment responders and non-responders. RESULTS: Eighty patients were included in the analysis; the mean number of prior therapies was 7.9 (standard deviation [SD] 3.1), and mean duration of myeloma was 7.6 years (SD 3.4). Each exploratory minimal clinically important difference threshold yielded consistent results whereby most patients did not experience HRQoL decline during the first six cycles of treatment (range: 53.9 to 75.7% for the first approach; range: 52.6 to 72.9% for the second). Treatment responders experienced less decline in HRQoL from baseline to EOT than non-responders, which was significant for the FACT-G, but not for other scores. CONCLUSION: The majority of patients did not experience decline in HRQoL based on minimal clinically important differences during early cycles of treatment with selinexor and dexamethasone in the STORM trial. An anchor-based approach utilizing patient-level data (ECOG PS score) to define minimal clinically important differences for the FACT-MM gave consistent results with a distribution-based approach. TRIAL REGISTRATION: This trial was registered on ClinicalTrials.gov under the trial-ID NCT02336815 on January 8, 2015.