Citations 383

Fractionated Dosing of CLR 131 in Patients with Relapsed or Refractory Multiple Myeloma (RRMM)

Blood | February 14, 2020 | Volume: 134 | Issue: Supplement_1 | Pages: 144-144

10.1182/blood-2019-131014

Background: CLR 131 is a novel targeted radiotherapeutic that exploits the selective uptake and retention of phospholipid ethers (PLEs) by malignant cells. Based on initial preclinical and clinical experience and the radiosensitivity of MM, fractionated dosing of CLR 131 is being examined in RRMM in a Phase 1 trial (NCT02278315) and a Phase 2 trial, CLOVER-1 (NCT02952508). Methods: Both the Phase 1 and Phase 2 trials of CLR 131 aim to determine efficacy and safety in RRMM. Eligibility criteria include progressive or relapsed MM that is refractory to at least 1 proteasome inhibitor (PI) and 1 immunomodulatory (IMiD) drug with no upper limit to the number of prior lines of therapy. Prior autologous stem cell transplant (ASCT) and external beam radiation therapy are allowed (< 20% of total marrow irradiated). The Phase 1 trial was a single and fractionated ascending dose escalation safety study and the Phase 2 trial is evaluating 3 doses: a bolus dose and 2 fractionated doses. The fractionated doses of CLR 131 included infusion of either 31.25 mCi/m2 CLR 131 or 37.5 mCi/m2 CLR 131 (administered as 15.625 mCi/m2 or 18.75 mCi/m2, respectively, on day 1 and day 7 (± 1 day)) administered as a 30-minute intravenous infusion is reported here. Adverse events (AEs) are graded by NCI-CTCAE v4.03. Responses were determined using IMWG criteria as assessed by the investigator. Results: As of 30Jul2019, 10 subjects have received fractionated 31.25 mCi/m2 and 6 subjects fractionated 37.5 mCi/m2 CLR 131. In addition, 1 subject was scheduled to receive fractionated 37.5 mCi/m2 CLR 131 but died due to progressive disease prior to administration of the second dose; this subject is not included in the analyses below as they did not receive both fractionated doses. There is no upper age limit for enrollment and the median age for the 16 RRMM patients was 71 (range 51-83), including 6 females and 10 males with a median of 4 prior therapies (range 2 to 13). Seven patients had prior ASCT. CLR 131 demonstrated 100% disease control rate in subjects receiving either fractionated dose of CLR 131. The overall response rate (ORR) in the fractionated 37.5 mCi/m2 cohort is 50%. Three subjects in the cohort experienced a partial responses (PR), median time to response 43 days, and the other three had minimal responses (MR) with an average 39% reduction in m-protein. In this cohort, 80% of the subjects were either quad- or penta-refractory; all 80% were refractory to daratumumab. There were two subjects in the 31.25 mCi/m2 cohort with non-secretory disease and their status was followed by FDG-PET imaging. Both have been excluded from the evaluation of efficacy as their disease does not meet with IMWG criteria for response. No patients in this cohort achieved a PR or better however a majority of the subjects experienced a minimal response. The primary AEs include thrombocytopenia, anemia, neutropenia, and fatigue (Table 2). The hematologic AEs were expected, manageable and followed a predictable timeline to nadir (average. 40 days) and subsequent recovery (average 17 days post nadir). Conclusions: CLR 131 is a unique, first in class targeted radiotherapeutic for RRMM. Preliminary data for CLR 131 administered as a fractionated dose shows an acceptable and expected safety profile in this patient population. Fractionated dosing at 37.5 mCi/m2 has shown an efficacy signal and has been adopted as the standard for CLR 131 dosing in ongoing and future trials. Dose escalation to determine the highest tolerated dose is ongoing in the Phase 1 study and is currently examining a fractionated infusion of 40 mCi/m2 administered as 20 mCi/m2 CLR 131 on day 1 and day 7 (± 1 day). Based upon these data enrollment to the fractionated 37.5 mCi/m2 cohort of the Phase 2 trial continues. Disclosures Ailawadhi: Celgene: Consultancy; Amgen: Consultancy, Research Funding; Pharmacyclics: Research Funding; Cellectar: Research Funding; Janssen: Consultancy, Research Funding; Takeda: Consultancy. Stiff:Gilead/Kite Pharma: Consultancy, Honoraria, Research Funding; Amgen: Research Funding; Gamida-Cell: Research Funding; Incyte: Research Funding; Cellectar: Research Funding; Unum: Research Funding. Ibrahim:Cellectar: Honoraria, Research Funding; Incyte: Research Funding; Pfeizer: Research Funding; Puma: Research Funding; Eli Lilly: Research Funding; Hoffman-LaRoche: Research Funding; Spectrum: Research Funding; Takeda: Research Funding. Cull:Celgene: Speakers Bureau; ADC Therapeutics: Research Funding. Green:GSK: Consultancy; Seattle Genetics: Research Funding; Juno Therapeutics: Consultancy, Patents & Royalties, Research Funding; Celgene: Consultancy; Cellectar: Research Funding. Oliver:Cellectar Biosciences: Employment. Longcor:Cellectar Biosciences: Employment, Equity Ownership.
Trends in Early Mortality from Multiple Myeloma (MM): A Population-Based Analysis

Blood | February 14, 2020 | Volume: 134 | Issue: Supplement_1 | Pages: 71-71

10.1182/blood-2019-124799

Background: Survival of patients with MM has improved significantly over recent years due to therapeutic advancements. Population-level data has shown that a substantial proportion of MM patients may die early after their diagnosis and real-world evidence regarding early mortality (≤6 months after MM diagnosis) has been conflicting. We evaluated the trends, causes and predictors of early mortality among newly diagnosed MM (NDMM) patients in the real world. Methods: We used Surveillance Epidemiology and End Results (SEER) database, to identify all adult patients (age ≥ 18 years) who were diagnosed of MM from 1975 to 2015. Data on age, gender, geographical regions, year of diagnosis, survival time, vital status at 6 months after diagnosis and cause of death (COD) were extracted. Ages were categorized as quartiles while period of diagnosis for multivariate analysis were categorized by running a joinpoint analysis separately for the all-cause and myeloma-specific mortality. To look at trends in early mortality, we estimated proportion of deaths for each year and plotted it as a scatterplot against the year of diagnosis and fitted it in the join point regression model by applying the NCI's Join point Regression Program, Version 4.5.0.1. By this method we identified the year(s) when a trend change was produced, calculated the annual percentage change (APC) in rates between trend-change points, and the average annual percentage change (AAPC) in the whole period studied. To correct for known errors with COD attribution, we applied a special COD variable which has been recently developed by the SEER program to indicate if the death was due to the primary cancer diagnosis or other causes. A multivariate analysis was conducted to analyze the predictors of all-cause and myeloma-specific mortality within 6 months by fitting into logistic regression model. Results: Of 90,975 NDMM patients, early mortality due to any cause was noted in 18,810 (20.7%). For the whole cohort, median age was 68 years, majority of the patients were males (53.1%), of non-Hispanic white (NHW) race/ethnicity (65.5%) and were diagnosed in SEER registries in the western region (53.9%). An overall survival (OS) of ≤6 months was seen for approximately 22% of NHW but 18% of non-Hispanic blacks (NHB) and Hispanics. OS of ≤6 months was seen in 10% of patients in the first quartile of age (<60 years) as compared to 36% of patients in the 4th quartile (≥78 years). By geographical regions, 23.3% of MM patients in the Midwest had ≤6-month OS as compared to only 18.4% in the Northeast. The most common early mortality COD was MM in 74.7% of the patients, followed by cardiovascular (11.9%), other (8.8%) and infectious causes (3.1%). The overall pattern of COD at 6 months was similar to COD at any time in the whole cohort. Joinpoint regression analysis of trends data resulted in 1 joinpoint for all-cause 6-month mortality while 2 joinpoints were noticed for myeloma-specific mortality (Figure 1). A steep decline in mortality was noticed in the more recent time periods for both, all-cause (2006-2015) and myeloma-specific (2003-2015) mortality rates with an AAPC of 3.93 (95%CI p<0.001) for all-cause and 3.95 (95%CI p<0.001) for myeloma-specific mortality. Prior to 2006, the decrease in all-cause mortality was only modest whereas decrease in myeloma-specific mortality witnessed a sharp decline from 1975-1987 as well. On MVA, advanced age (p<0.001), NHW race/ethnicity and Midwest geographic region (p<0.001) were associated with higher likelihood of mortality while female gender (p<0.001), more recent period of diagnosis (p<0.001), and "other" races (not NHW, NHB or Hispanics) (p<0.001) were associated with lower risk of mortality. Conclusion: Our results show that early mortality due to MM remains high despite therapeutic improvements and there are significant gender, racial and geographic disparities for this phenomenon. However, significant declines in all-cause and MM-specific early mortality in the more recent times are promising. The risk of early mortality is higher among men, older patients, NHW and Midwest region. A focus on interventions to reduce early mortality, including early diagnosis, use of efficacious anti-MM therapy and aggressive supportive care should be directed at groups with high-risk for early mortality from MM. Disclosures Chanan-Khan: Millennium: Research Funding; Ascentage: Research Funding; AbbVie: Research Funding; Xencor: Research Funding; Pharmacyclics: Research Funding; Merck: Research Funding; Jansen: Research Funding; Mayo Clinic: Employment. Ailawadhi:Celgene: Consultancy; Pharmacyclics: Research Funding; Amgen: Consultancy, Research Funding; Takeda: Consultancy; Cellectar: Research Funding; Janssen: Consultancy, Research Funding.
Autologous Stem-Cell Transplantation for Multiple Myeloma in the Era of Novel Therapies

JCO Oncology Practice | February 11, 2020 | Volume: 16 | Issue: 2 | Pages: 56-66

10.1200/jop.19.00335 | PMID 32045556

Despite the evolution of the therapeutic arsenal for the treatment of multiple myeloma (MM) over the past decade, autologous stem-cell transplantation (ASCT) remains an integral part of the treatment of patients with both newly diagnosed and relapsed MM. The advent of novel therapies, such as immunomodulatory agents, proteasome inhibitors, and monoclonal antibodies, has led to unprecedented levels of deep hematologic responses. Nonetheless, studies show that ASCT has an additive effect leading to additional deepening of responses. As the therapeutic agents for MM continue to evolve, the timing, duration, and sequence of their use in combination with ASCT will be crucial to understand to obtain the deepest response and survival benefit for patients with MM. This review aims to discuss the role of ASCT for the management of MM, with a particular focus on the role of ASCT in the context of novel therapies and minimal residual disease.
Timeliness of Initial Therapy in Multiple Myeloma: Trends and Factors Affecting Patient Care

JCO Oncology Practice | January 21, 2020 | Volume: 16 | Issue: 4 | Pages: e341-e349

10.1200/jop.19.00309 | PMID 32048939

Multiple myeloma (MM) treatment has advanced significantly over the last 2 decades. In most patients, the disease course has been altered from early fatality to chronic morbidity with multiple lines of treatment. The MM treatment paradigm has shifted toward treating patients before end-organ damage occurs. Thus, timeliness of treatment initiation in this era might improve patient outcomes. This is the first report to our knowledge analyzing disparities and trends in treatment timeliness of patients with MM using the National Cancer Database. Multiple factors affected the timing of treatment initiation in MM and disparities were found. We noted that initiation of treatment was delayed in women (odds ratio [OR], 1.15; 95% CI, 1.1 to 1.2) and blacks (OR, 1.21; 95% CI, 1.14 to 1.28; reference, whites) and in patients diagnosed in more recent years (2012-2015; OR, 1.15; 95% CI, 1.1 to 1.22; reference, 2004-2007). Patients were likely to start treatment earlier if they were age ≥ 80 years (OR, 0.83; 95% CI, 0.76 to 0.9; reference, age < 60 years), were uninsured (OR, 0.81; 95% CI, 0.72 to 0.91; reference, private insurance), had Medicaid (OR, 0.87; 95% CI, 0.79 to 0.95; reference, private insurance), were treated in a comprehensive community cancer program (OR, 0.7; 95% CI, 0.65 to 0.77; reference, community cancer program), lived in a location other than the US Northeast, or had a higher Charlson comorbidity score. Patient education and income levels did not affect time to treatment initiation. Particular aspects of these disparities could be explained by our current health care system and insurance rules, whereas others need to be investigated more deeply.
A meta-analysis of genome-wide association studies of multiple myeloma among men and women of African ancestry

Blood Advances | January 14, 2020 | Volume: 4 | Issue: 1 | Pages: 181-190

10.1182/bloodadvances.2019000491 | PMID 31935283

Abstract Persons of African ancestry (AA) have a twofold higher risk for multiple myeloma (MM) compared with persons of European ancestry (EA). Genome-wide association studies (GWASs) support a genetic contribution to MM etiology in individuals of EA. Little is known about genetic risk factors for MM in individuals of AA. We performed a meta-analysis of 2 GWASs of MM in 1813 cases and 8871 controls and conducted an admixture mapping scan to identify risk alleles. We fine-mapped the 23 known susceptibility loci to find markers that could better capture MM risk in individuals of AA and constructed a polygenic risk score (PRS) to assess the aggregated effect of known MM risk alleles. In GWAS meta-analysis, we identified 2 suggestive novel loci located at 9p24.3 and 9p13.1 at P &lt; 1 × 10−6; however, no genome-wide significant association was noted. In admixture mapping, we observed a genome-wide significant inverse association between local AA at 2p24.1-23.1 and MM risk in AA individuals. Of the 23 known EA risk variants, 20 showed directional consistency, and 9 replicated at P &lt; .05 in AA individuals. In 8 regions, we identified markers that better capture MM risk in persons with AA. AA individuals with a PRS in the top 10% had a 1.82-fold (95% confidence interval, 1.56-2.11) increased MM risk compared with those with average risk (25%-75%). The strongest functional association was between the risk allele for variant rs56219066 at 5q15 and lower ELL2 expression (P = 5.1 × 10−12). Our study shows that common genetic variation contributes to MM risk in individuals with AA.
Economic Evaluation of Carfilzomib+Dexamethasone (Kd) Vs Bortezomib+Dexamethasone (Vd) in Relapsed or Refractory Multiple Myeloma (R/RMM)

Blood | November 18, 2019 | Volume: 128 | Issue: 22 | Pages: 3582-3582

10.1182/blood.v128.22.3582.3582

Abstract Background : Carfilzomib is an innovative second generation proteasome inhibitor (PI) that binds irreversibly and selectively to the proteasome. Carfilzomib exhibits sustained inhibition of the proteasome with minimal off-target activity. Kd was approved in 2016 as a treatment (Tx) option for R/RMM patients who have received one to three prior lines of therapy.In the ENDEAVOR phase 3, open label, multicenter randomized controlled trial assessing Kd vs Vd, median progression-free survival (PFS) was 18.7 months (95% CI:15.6 - could not be estimated) in the Kd group vs 9.4 months (8.4 - 10.4) in the Vd group at an a priori, pre-specified interim analysis (hazard ratio [HR]: 0.53 [95% CI: 0.44 - 0.65]; p<0.0001). OS data at the 1st interim analysis were immature. In the current study, we assessed the cost-effectiveness (CE) of Kd vs Vd from a US payer perspective using data from ENDEAVOR and long-term overall survival (OS) data from the Surveillance, Epidemiology, and End Results Program (SEER). Methods: A partitioned-survival model with a progression-free (PF), a post-progression (PP) and a death state was built with a 30 year horizon. PFS was modelled using separately fitted log-logistic parametric curves. In order to estimate measures of efficacy for OS and to incorporate treatment effect into the model, time-dependent multiple semiparametric Cox regression analyses were implemented for OS outcomes, which controlled for baseline covariates. OS for Vd in the base case was modelled with a separately fitted Weibull parametric curve, which was fitted to the Vd data. The time-dependent multiple Cox model generated a HR for 0 to 12 months and a HR beyond 12 months for Kd vs Vd, which were applied to model the Kd OS curve. The OS curves beyond 36 months were extrapolated with SEER data. A Weibull distribution was used for the extrapolation by matching the SEER registry data to the ENDEAVOR population, which was assumed to represent the Vd survival rate. To this extrapolated survival curve beyond 36 months, the OS treatment effect was applied in order to model the Kd curve. Grade ≥ 3 adverse events (AEs) with ≥ 2% incidence in any ENDEAVOR arm were included. Utilities were derived from the literature and adjusted for the treatment specific improvement in QoL observed when patients were PF in ENDEAVOR. Costs related to drug (WAC prices), administration, monitoring, AE management, and subsequent Tx were considered. The base case utilized OS results from an updated OS dataset (March 2016) that resulted in an ad hoc OS analysis. A 3% discount rate was applied to costs and health outcomes. Results: In the base-case, results from the model showed thatKd was more effective compared to Vd, providing 1.874 PfLY, 1.854 LY, and 1.654 QALY gains over the modelled horizon. Kd incurred $227,703 in total additional costs and the ICER vs Vd was 137,660$/QALY. Conclusions: The model predicts that Kd delivers 1.85 additional life years over the the comparator Vd. Per the base case, Kd is cost-effective vs Vd at generally accepted willingness-to-pay thresholds of $150,000/QALY and $300,000/QALY in the US. Based on the ENDEAVOR data, Kd is a superior PI-based doublet compared to Vd, and should be preferred whenever doublets are appropriate for the patient, Furthermore, this CE analysis shows that Kd delivers considerable incremental value to patients with relapsed or refractory MM and to payers who must allocate budgets for the treatment of patients. Table Table. Disclosures Jakubowiak: Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen Inc.: Consultancy, Honoraria, 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; SkylineDx: 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; BMS: 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. Majer:Amgen Inc: Employment, Equity Ownership. Houisse:Amgen Inc: Consultancy. Benedict:Amgen Inc: Consultancy. Campioni:Amgen: Employment, Other: Holds Amgen Stock. Panjabi:Amgen Inc: Employment, Equity Ownership. Ailawadhi:Pharmacyclics: Consultancy; Novartis: Consultancy; Amgen Inc: Consultancy; Takeda Oncology: Consultancy.
Methylation Patterns in Waldenströms Macroglobulinemia Cells That Are Inherently Resistant or Have Acquired Resistance to Bortezomib, Converge on the TP63 and Cepba Family of Transcription Factors

Blood | November 17, 2019 | Volume: 124 | Issue: 21 | Pages: 3551-3551

10.1182/blood.v124.21.3551.3551

Abstract Background: Waldenstršms macroglobulinemia (WM) is an indolent B-lymphoplasmacytic lymphoma, which is highly sensitive to 20S proteasome inhibitors such as bortezomib. However, clinical resistance to the drug can be observed early at onset of therapy (primary or inherent resistance) or develop over time, through repeated exposure to the drug (acquired resistance). Although prior investigations into the biological mechanisms associated with bortezomib resistance (BR) have identified aberrations at the genomic (PSMB5 mutation) and transcriptional level (loss of XPB-1), there is limited data on the epigenetic abnormalities that support resistance to 20S proteasome inhibition. With this in mind, we conducted a comprehensive methylation and mRNA expression analysis in WM cells focusing on the molecular patterns that characterize inherent BR (iBR) as well as acquired BR (aBR). Materials and Methods: Bortezomib sensitive (BS) human WM cell lines, BCWM.1 and MWCL-1, the iBR WM cell line RPCI-WM1 (developed from a bortezomib-refractory WM patient) as well as aBR subclones (BCWM.1/BR, MWCL-1/BR) were used in the study. Methylation status of WM cells was profiled by Illumina Infinium 450k methylation array. Methylation IDAT files were background subtracted using GenomeStudio v1.9. Beta mixture quantile dilation (BMIQ) method in R watermelon package was used to adjust type II probes into distribution characteristic of type I probes. For each gene, probes were partitioned into 6 regions using R IMA package and the ones belonging to the same region were averaged, including transcription start sites (TSS; both 200 bp and 1500 bp upstream), 5' untranslated region (UTR), and 3'UTR, the first exon, and genebody. Gene regions showing a significant adjusted p-value and a beta difference of >0.1 or <-0.1 were selected for differential hypermethylation and hypomethylation, respectively. Correlation with gene expression was conducted only on genes showing >1.5 fold change in expression. Overview of methodology is shown in Figure 1. Results: We first assessed the differential methylation pattern (TSS, 200bp upstream of gene body) of bortezomib-sensitive (BS, BCWM.1, IC50 6nM) and iBR cells, (RPCI-WM1). A total of 3,801 hypermethylated and 1,865 hypomethylated DNA regions were observed in iBR cells relative to BS cells (Figure 2A). In iBR cells, a negative correlation between hypermethylated DNA and corresponding gene expression was found in 1,039 genes (Spearman r = -0.12) (Figure 2B). In parallel, we compared the methylation pattern (TSS 200bp) of BS WM cells (BCWM.1 and MWCL-1) with their aBR derivatives, which display ~20 – 50 fold resistance to bortezomib. aBR subclones showed differential hypermethylation of 1,521 DNA regions and hypomethylation of 651 genomic regions relative to BS WM cells. These findings were not unexpected as aBR cell lines, being derivatives of BS WM cells, are clonally related to the former, whereas iBR cells are derived from a different clone. Meta-analysis of iBR and aBR followed by pathway enrichment (NextBio, Illumina Inc), revealed a significant clustering of commonly hypermethylated genes within the Validated Transcriptional Targets of TP63 isoforms Canonical Pathway (p<1.9-E5, Figure 2C) and the CEBPA binding site Geneset 2 (p<8.2-E9, Figure 2D); pathways whose genes are actively involved in suppression of cell growth and differentiation. Further validation and functional relevance of candidate gene targets from this analysis, which are relevant to WM pathobiology, are currently being investigated. Conclusion: This is the first study to examine and correlate the global methylation and gene expression profiles in WM tumor cells that are inherently wired to resist 20S proteasome inhibition as well as tumor cells, which have acquired resistance through continuous exposure to bortezomib. Although considerable differences were observed in the methylation profiles of WM cells displaying inherent vs. acquired resistance, a number of common genes emerged and pointed towards transcriptional repressors, whose inactivation through methylation has been linked to other cancers. Altogether, these findings uncover cellular systems in WM cells, which are affected by DNA methylation, subsequent mRNA suppression and which may be associated as a whole with both inherent and acquired forms of bortezomib resistance. Disclosures No relevant conflicts of interest to declare.
Targeted Disruption of USP14 and UCHL5 with the Novel Deubiquitinase Enzyme (DUB) Inhibitor, VLX1570, Induces Immense Proteotoxicity and Cell Death in Malignant Plasma Cells

Blood | November 17, 2019 | Volume: 124 | Issue: 21 | Pages: 3116-3116

10.1182/blood.v124.21.3116.3116

Abstract Background: Deubiquitinating enzyme (DUB) inhibitors are an emerging class of compounds, which are increasingly being regarded for their anti-cancer activity and therapeutic potential. The 19S regulatory particle of the proteasome contains two DUBs, USP14 and UCHL5, which are critical for the proper unfolding and deubiquitination of proteins prior to their entry into the 20S proteasome β-catalytic core. In B/plasma cell malignancies such as Waldenströms macroglobulinemia (WM) and multiple myeloma (MM), protein homeostasis and optimal proteasome functionality are paramount for tumor survival. This is evidenced by the success of 20S proteasome inhibition with bortezomib and carfilzomib, which have demonstrated remarkable clinical benefit in patients with WM or MM. As such, the proteasome degradation pathway represents a highly attractive and clinically validated, yet still largely unexplored therapeutic target. Here, we provide first evidence of the cytotoxic effects and molecular sequelae associated with a novel 19S proteasome DUB inhibitor, VLX1570, which selectively targets USP14 and UCHL5, in preclinical models of B/plasma cell cancers and their drug resistant tumor subclones. Materials: VLX1570 was obtained from Vivolux AB, Sweden. Bortezomib was purchased from Sellekchem, Houston TX. Human myeloma cell lines (OPM2, U266, KMS11), human WM cell lines (BCWM.1, MWCL-1 and RPCI-WM1), their respective bortezomib-resistant (BR) subclones as well as ibrutinib-resistant (IR) derivatives of BCWM.1 and RPCI-WM1 were used in experiments (total n=12). Peripheral blood mononuclear cells (PBMCs) from healthy donors were used to assess for cytotoxicity of VLX1570 in non-tumor cells. Results: A 72hr MTS assay first established sensitivity of plasma cell cancer models towards VLX1570, including drug resistant subclones (EC50 range, 20 – 90nM). Next we assessed whether loss of viability was due to apoptosis and observed dose-dependent annexin-V staining in ~50 – 70% of wild-type MM and WM cells, ~45 – 55% in corresponding BR models and ~50% in IR subclones when exposed to VLX1570 (100nm – 500nM) for 24hrs. VLX1570 was tested at similar concentrations in PBMCs and induced minimal cell death. To understand if VLX1570-induced apoptosis was mitochondrial mediated, we assessed mitochondrial outer membrane permeability (MOMP) in all plasma cell cancer models treated with the DUB inhibitor (100 – 500nM) and found a dose-dependent increase in MOMP (p<0.00025 – 0.000001). Activation of the mitochondrial/intrinsic apoptotic pathway was also evidenced by cleavage of caspase-9 and 3 on immunoblot analysis. As inhibition of protein deubiquitination results in accumulation of polyubiquitinated protein conjugates, we examined global ubiquitinated protein levels and found increasing amounts of high molecular weight poly-ubiquitinated protein in VLX1570 treated tumor cells in a dose-dependent manner. This prompted us to further delineate the potential cellular response mechanisms that relay the antitumor activity of VLX1570 in malignant plasma cells. Immunoblot analysis of drug sensitive and (bortezomib or ibrutinib) resistant MM and WM cell lines revealed several changes in ER stress response proteins, notably induction of HSP70 and splicing of XBP1; the latter event which was less prominent in BR cell lines treated with bortezomib. This suggested the ability of VLX1570 to overcome resistance through a rapid and potent proteotoxic effect, which overwhelmed the tumor cells stress response mechanisms beyond its capacity for survival. Finally, as abnormalities in the NFkB signaling pathway are implicated in malignant plasma cell survival, we found markedly decreased nuclear translocation of NFkB (p-P65) protein in tumor cells treated with VLX1570. Conclusions: The DUBs of the 19S proteasome cap offer an attractive target within the proteasome degradation system and whose inhibition by VLX1570 is able to circumvent mechanisms that support resistance to b-catalytic PI (bortezomib) or BTK inhibitor (ibrutinib) therapy. The studies undertaken thus far, coupled with more rigorous mechanistic and in vivo efficacy analyses currently underway, provides rational for the clinical development of DUB inhibitors for use in malignant B/plasma cell malignancies. Disclosures Martin: Janssen: Honoraria.
Racial/Ethnic Disparities in NK/T-Cell Non-Hodgkin Lymphomas in the US: A SEER Analysis

Blood | November 17, 2019 | Volume: 128 | Issue: 22 | Pages: 3612-3612

10.1182/blood.v128.22.3612.3612

Abstract Background: NK/T cell non-Hodgkin lymphomas (NK/T NHL) are rare high-grade lymphomas that are diagnostically challenging and carry a poor prognosis. Incidence is notably higher in Asian countries as compared to North America and Europe. South Americans have an incidence similar to Asian countries though less well described. In this study we reviewed the incidence and outcomes of NK/T NHL in the US with a specific focus on patient race/ethnicity. Methods: Surveillance, Epidemiology and End Results (SEER) database was used to examine the standardized incidence rates (SIR) of NK/T cell NHL among adult (≥18 yrs) patients diagnosed between 1992-2013. Mutually exclusive race/ethnicity categories were: African-Americans (AA), Asians/Pacific Islanders (API), Hispanic whites (HW) and Non-Hispanic whites (NHW). Cases that received a diagnosis at death certificate/autopsy, no follow-up records, or lacking age at diagnosis, sex, or race/ethnicity documentation were excluded. Age adjusted incidence rates (AAIR) were calculated by race. Cox proportional hazards models, adjusted for confounding variables, were used to evaluate association between patient demographics and overall survival (OS). Results: A total of 706 cases met inclusion criteria. Of these, 64% were males and 36% females. AAIR was higher in males irrespective of race/ethnicity. Among different race/ethnic subgroups, API and HW had a higher AAIR than NHW and AA (0.2, 0.18, 0.05 and 0.04, respectively) (Figure 1). Median OS for males and females was similar (1.8 yr and 2 yr, respectively; p=0.76) There was a statistically significant difference in median OS by age for all patients with 4.3 yr for age 18-44 as compared with 0.8 yr for age >75 yr (p<0.001). Median OS by was different for HW (1.3 yr), API (1.8 yr), AA (2.3 yr) and HW (2.5 yr) but did not reach statistical significance (p=0.45). Median OS by stage varied as 7.3 yr for stage IE to 0.9 yr for all other stages combined (p<0.001) Cases with disease location as nasal cavity or sinus had a median OS of 3.5 yr as against 1.1 yr for those with all other sites (p<0.001) (Table 1). Conclusions: Significant disparities exist in the US for NK/T NHL incidence by race and gender, with highest AAIR among the racial minorities of API and HW, which are fastest and second fastest growing minority groups in the US respectively. Increasing age, advanced disease stage and site outside of the nasal cavity or sinus are independent predictors of poor prognosis. Some differences do exist in survival by race. These factors need to be considered for better resource allocation and utilization for this rare, often incurable and aggressive disease. Figure 1 Figure 1. Disclosures Ailawadhi: Pharmacyclics: Consultancy; Novartis: Consultancy; Amgen Inc: Consultancy; Takeda Oncology: Consultancy. Kelly:Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Consultancy, Speakers Bureau; Novartis: Consultancy, Speakers Bureau.
Trends in Disease Presentation, Management, Cost of Care and Outcomes: A Comprehensive Look at Racial Disparities in Multiple Myeloma (MM)

Blood | November 17, 2019 | Volume: 128 | Issue: 22 | Pages: 3544-3544

10.1182/blood.v128.22.3544.3544

Abstract Background: Disparities in MM survival among different racial groups persist despite improvements in overall survival (OS). We report a comprehensive review of the SEER Medicare database to elucidate the causes of differences in disease presentation, management practices, cost of care and their relationships to outcomes among the MM patients (pts) from different racial groups. Methods: Pts diagnosed with MM between 1991-2010 with continuous Medicare coverage (1 year prior to diagnosis-date of death/end of 2012) were included. MM complications (MM-C); hypercalcemia (C), renal dysfunction (R), anemia (An), bone fractures (B), dialysis (D) occurring prior to/within 30 days of MM diagnosis (at diagnosis; AT-D), or any time later (after diagnosis; AF-D) were summarized. Demographics, survival (PEDSAF files) and disease characteristics, drug/stem cell transplant (SCT) utilization (NCH, OUTSAF, PDESAF files) were obtained. Trends in incidence of MM-C, treatment type over time (proportional odds) and their association with race (logistic regressions) were compared. Associations between race, MM-C AT-D and MM related death using Fine and Gray's competing risk methods were analyzed. Medicare claims adjusted for inflation (2013) within the first 6 months (mth)/total MM care were summed by drug and total charges. Median cost of care by race and year of diagnosis were evaluated by Kruskal-Wallis (univariate) and proportional odds models (multivariate). Results: A total of 35842 pts (52.1% males) with median age of 76 yr (range 18-104) were included. Mutually exclusive racial subgroups were: White (W, 72%), Hispanic (H: 7.3%), African-American (AA, 16.2%), Asian (A, 4.1%), other (0.3%). A significantly increasing trend in the prevalence of all MM-C AT-D was seen over time (all p<0.001). For AF-D, all MM-C initially increased but decreased from 2006-2010 except D that showed continued increase (Fig 1A). For race, MM-C were significantly different, with AA having the most C, R, An and D while W having the most B (Fig 1B). Inferior OS was seen with male gender (p=0.006), increasing age, earlier years of diagnosis, belonging to W or H race, C, R and B (all p<0.001), but not with An (p=0.298) or D (p=0.378). Trends in OS over time showed a significant interaction with race in 1991-1995 (p<0.001), 1996-2000 (p=0.004) and 2001-2005 (p<0.001) but not in 2006-2010 (p=0.182), possibly due to shorter follow up. Medicare claims analysis showed that pts receiving any treatment increased from 12.8% in 1991-1995 to 59.3% in 2006-2010 (p<0.001). Specific therapy utilization, including SCT and all drug classes/agents evaluated increased except for cytotoxic chemotherapy utilization (melphalan/cyclophosphamide), which decreased (Fig 2A). Any therapy utilization was significantly different by race (p<0.001) with highest for H (36.5%) and lowest for AA (31.6%). Specific treatments differed significantly by race (Fig 2B). Cost of care analysis showed significant increase over years for median drug claims (0.23k to 3.63k) and total claims (5.11k to 27.8k) during first 6 mth as well as for any time after MM diagnosis (drug: 1.3k to 9.9k, total: 21.9k to 84k) (p<0.001 for all). Median drug claims in first 6 mth were highest among AA (1.3k) and lowest among A (0.63k) (p<0.001). Same was true for total claims in first 6 mth (p<0.001). For any time after diagnosis, H had the highest drug (p<0.001) and total (p=0.081) claims. There were significant interactions between year of diagnosis, race and cost of care with H seeing the highest increase in drug claims in first 6 mth (p<0.001) and any time (p=0.002). Conclusion: MM-C have generally decreased AF-D due to improved therapeutics although AA continue to have the highest rates of MM-C. Our data shows that utilization and cost of MM care have increased tremendously with resulting improved outcomes, but significant racial disparities persist. These disparities may be in part due to impaired access to new agents from lack of supplemental insurance for certain racial groups. Drug utilization and cost of care disparities may also be due to differences in co-morbidities, MM-C or access leading to differential healthcare utilization and should be explored in order to ameliorate disparities in outcomes. Disclosures Ailawadhi: Pharmacyclics: Consultancy; Novartis: Consultancy; Amgen Inc: Consultancy; Takeda Oncology: Consultancy.