ALBERT

Description: Abstract 1857 Background: Multiple myeloma (MM), the second most common hematologic cancer in the United States, has a 5-year survival rate of 38%. Bendamustine is a unique alkylating agent with multiple actions leading to cancer cell death in several tumor types. In patients with MM, bendamustine, alone and in combination with prednisone, has been shown to be efficacious, with durable responses. Bortezomib is a proteasome inhibitor approved as monotherapy for MM. It has been found to sensitize highly chemoresistant MM cell lines to alkylating agents such as melphalan. Subsequent clinical trials have reported anti-MM activity and acceptable safety for bortezomib plus melphalan for relapsed or refractory MM and for bortezomib, ascorbic acid, and melphalan (BAM) for patients with newly diagnosed MM. The present phase 1/2 study assessed the safety, tolerability, and efficacy of bortezomib plus bendamustine for patients with relapsed or refractory MM. Methods: All patients were ≥18 years old and had biopsy-confirmed MM, measurable by a serum monoclonal immunoglobulin spike ≥1 gm/dL and/or a urine monoclonal spike ≥200 mg/24 hours. Also, all patients received ≥1 prior MM treatment, not including bendamustine, and showed signs or symptoms of progressive disease, either relapsed (progression following stabilization or response) or refractory (progression during or within 6 months after an antimyeloma regimen). Patients were enrolled in successive groups of 3 to 5. The groups received open-label bendamustine administered as a 1-hour intravenous (IV) infusion of 50, 70, or 90 mg/m2 on days 1 and 4 of each 28-day treatment cycle. Each infusion was preceded by bortezomib administered as a 3- to 5-second IV push of 1.0 mg/m2. Bortezomib was also given on days 8 and 11. Enrollment at each dose level was permitted only if the first 3 patients at the previous level received 1 cycle without unacceptable dose-limiting toxicity (DLT). If not, an additional 3 patients would be treated at the previous level (for a maximum 6 at each level). The maximum tolerated dose was defined as the highest dose at which

Description: Introduction: Myelodysplastic syndromes (MDS) are a heterogenous group of blood disorders defined by peripheral cytopenia(s), bone marrow failure, morphological dysplasia, and risk of progression. To understand the genetic, epigenetic and biological factors associated with the initiation and progression of MDS, NHLBI created the National MDS Study (NCT02775383). This is a prospective cohort study conducted at 92 community hospitals and 29 academic centers enrolling patients undergoing diagnostic work up for suspected MDS or MDS/myeloproliferative neoplasm (MPN) overlap syndrome. Eligible patients have yet to receive any therapy directed at their cytopenias. Previously untreated cytopenic participants underwent centralized histopathology and data review at the time of enrollment for assignment into distinct subcategories: MDS, MDS/MPN overlap, AML, and Other. Targeted exon sequencing of 96 genes was performed using marrow specimens from the first 300 consecutive individuals in the study. Here we report the genetic mutations for this cohort. Methods: NovaSeq 6000 was used for deep sequencing at a mean coverage of 1,286X and mean breadth (bases covered at ≥100X) of 99.8%. Reads were aligned against build GRCh38 using BWA-MEM, and VarScan2 was used to detect SNVs and INDELS. Variants were filtered for those with an allele base quality of 〉25 in combination with rule-based and manual review criteria. Subjects in the Other category without an identified malignancy were considered clonal cytopenias of undetermined significance (CCUS) when a mutation or a clonal cytogenetic change was present. Fisher's exact and Wilcoxon rank sum tests in combination with Bonferroni correction were applied to compare groups. Results : A total of 350 putative nonsynonymous pathogenic variants in 36 genes with an allele frequency of 〉.05 were identified across 150 patients (50%). At least one variant was noted in the following proportion of individuals: 61/72 (85%) with MDS, 13/13 (100%) with MDS/MPN, 15/17 (88%) with AML, and 61/198 (31%) in the Other category, of which 48 were CCUS and 13 were other cancers. Two CCUS patients only had a cytogenetic abnormality. Table 1 shows the distribution of variants in each subcategory of patients for the most commonly mutated genes in our cohort of 300 subjects. Mutations in these genes were enriched in specific groups: SF3B1, STAG2,TP53, and ASXL1 in MDS; TET2 in MDS/MPN; and IDH2 and TP53 in AML (one-sided p

Description: Abstract 3165 Background: Accrual to large oncology group studies in the United States is often slower than planned, especially in less common malignancies such as Multiple Myeloma (MM). To improve the treatment of patients with MM, it is essential that we address the barriers to accrual (BtA) to national clinical trials. The NCI Myeloma Steering Committee (MYSC) formed the Accrual Working Group (AWG), charged to analyze this problem. Methods: The members of the MYSC have developed a list of 10 potential BtA to NCI MM-CT under the leadership of the AWG at meetings conducted in person and by monthly telephone conference. This list was distributed via Survey Monkey among investigators and research staff of the SWOG, ECOG/ACRIN and Alliance research bases for the purpose of ranking the perceived importance of the 10 selected BtA. Responses based on a 0–5 Likert Scale were analyzed as continuous and categorical. For the latter, responses were grouped: Impedes Accrual – No (0,1), Yes (2–5); Significantly Impedes Accrual – No (0–3), Yes (4,5). Results: 246 survey responses were received. 50 participants who indicated that they had never attempted to or actually never enrolled a patient into a MM-CT were excluded. Of 196 responders, 61% had enrolled at least 5 patients, 43% practiced in academic centers (A) and 57% in community centers (C). 26% identified themselves as research staff, 74% as primarily physician investigators including Principal Investigators (12%). 78% have current access to NCI MM-CT. 46% identified their research base affiliation with SWOG, 20% with ECOG/ACRIN, 17% with Alliance, 17% as CTSU, NRG and other. The majority of survey responders confirmed agreement in the perception that all 10 identified BtA impede accrual, ranging from 60–84% depending on the specific barrier identified, while significant impediment to accrual ascribed to these BtA ranged from 22–47%. The perceived barriers most often cited as impeding accrual were (1) spectrum of available treatment options, (2) level of reimbursement for clinical trial related expenses and (3) patient‘s need for prompt treatment intervention (84%, 80%, 76% respectively). The first two barriers along with the requirement that patients receive their treatment exclusively at the NCI designated treatment site were rated most often as significantly impeding accrual (37%, 47%, 34% respectively). The first two were also identified most often as perceived BtA independent of practice setting (A, C), type of research engagement (physician investigator, research staff) and level of experience with MM-CT. Interestingly, the perception that patients must receive their treatment at the NCI designated treatment site and competing industry sponsored clinical trials were substantially more often cited as impeding accrual in academic centers compared to community centers and by physician investigators compared to research staff. The complexity of required diagnostic work up and the complexity of the treatment protocol and follow up testing were substantially more often cited as BtA in the community setting and by research staff compared to their peers in the academic setting and by physician investigators. The NCI MYSC AWG has proposed specific solutions to potentially lower perceived BtA. These include guidelines to allow protocol specific administration of commercially available agents by the patient‘s local oncologist, a simplified diagnostic work up and treatment plan and eligibility inclusion of patients who have received up to one cycle of specified urgent therapy prior to enrollment in MM-CT. Conclusions: We have queried experienced clinical investigators and research staff on 10 potential MM-CT specific BtA and found substantial consensus among responding participants in this survey. There are apparent differences in perceived BtA between the respondents from academic and community centers as well as between research staff and physician investigators. These data suggest that a structured approach to identification of BtA to clinical trials is feasible and creates opportunities to overcome them. This may have application to clinical trials across other diseases and may also lead to improvements in accrual. Disclosures: Barlogie: Celgene, IMF, MMRF, Millennium, Genzyme: Consultancy; Celgene, IMF, Millennium: Honoraria; Celgene, Novartis, NCI, Millennium, Onyx, Icon: Research Funding; GEP: Patents & Royalties.

Description: Background Myelodysplastic syndromes (MDS) are a collection of hematopoietic disorders with widely variable prognoses and treatment options. Pathologic diagnosis can be challenging and misdiagnosis can impact patient therapy and outcome. How commonly misdiagnosis occurs, and the severity of diagnostic errors, is not known. Here, we report interim analyses of patients (pts) with cytopenia and suspected MDS from the NHLBI National MDS Natural History Study (https://thenationalmdsstudy.net ClinicalTrials.gov: NCT02775383) assessing MDS occurrence and rates of agreement on classification of MDS/MDS-related disorders by local and centralized review. Methods Pts with cytopenias and clinically suspected MDS were identified between 6/16 and 6/18 from 84 participating centers in this ongoing multi-Institutional Cooperative Group study, with a goal of recruiting 2000 MDS (WHO 2016 subcategories), MDS/MPN or low blast count acute myeloid leukemia (AML,

Description: Introduction: The NHLBI National MDS Study (NCT02775383) is a prospective cohort study conducted at 92 community hospitals and 29 academic centers. It enrolls patients undergoing work up for suspected MDS to understand the genetic, epigenetic, and biological factors associated with the initiation and progression of the disease. Previously untreated, cytopenic participants undergo both local and centralized pathology review and are assigned a diagnosis, including MDS, MDS/MPN, AML with blasts 〈 30%, and "Other". Emerging data suggests that Next Generation Sequencing (NGS), along with cytogenetics and clinical variables, may improve MDS diagnostic precision. Given that our study relies on central review (with additional tertiary pathology review used to adjudicate disagreements), we examined whether targeted gene sequencing data could be used to increase the agreement between local and central pathologic diagnosis of MDS vs. Other. Methods: Peripheral blood and bone marrow (BM) biopsy specimens from cytopenic patients, along with clinical history, CBC, and other results including karyotyping, FISH and pathology reports from local pathologists were reviewed by central pathologists. The updated 2016 WHO classifications were used to diagnose MDS. Targeted exon sequencing of 96 genes was performed using BM specimens. A subset of 648 individuals that were classified as MDS (n=212) or Other (n=436, including 90 CCUS and 89 individuals with other cancers) by pathology assessments were selected. A mean coverage of 1,317X was achieved and variants had a minimum variant allele frequency (VAF) of 2% (except FLT3). Variants for 596 subjects were manually reviewed to retain likely disease-causing variants to build a binary classifier (MDS vs. Other) using the maximum VAF per gene as input (Figure 1). Subjects diagnosed with MDS or Other by both central and local pathology were used for training, validation, and testing, and were considered "gold standard" (GS) cases (n=546). These subjects were split into 4 random groups with equal proportions of MDS cases. 75% of the GS cases were used to train and validate lasso-regularized logistic regression models using 3-fold cross validation. ROC curve analysis was carried out using the remaining 25% of GS cases (Test Set 1) on the best model to identify an optimal probability cut off point for classifying subjects as MDS. Model performance was then tested on 50 subjects for which the central and local pathology diagnosis disagreed (Test Set 2), as well as on 52 additional subjects irrespective of agreement (Test Set 3). Results : The best performing logistic regression model retained 7 genes as most informative in a discriminating diagnosis of MDS from Other based on their VAFs, in order of impact: TP53, SF3B1, U2AF1, ASXL1, TET2,STAG2, and SRSF2. We used this model to assign probabilities for each of the subjects in Test Set 1 and to estimate the performance using ROC analysis (Figure 1), resulting in a high area under the curve (AUC) of 0.89. We chose a probability cut-off of ≥0.17, being associated with a high percentage of correct classification of MDS with a sensitivity and specificity of 0.90 and 0.81, respectively. Among the cohort of 50 subjects with a discordant local and central pathology diagnosis (Test Set 2), the classifier accurately reassigned 37 subjects (accuracy = 74%) from the local to the central pathology. The blinded tertiary pathology reviewer agreed with central in all Test Set 2 cases. This included 24/34 MDS cases that had been labeled as Other by local pathology (positive predictive value [PPV]=0.89). 3/16 final pathology-classified Other cases were mis-classified as MDS by the local pathologist (negative predictive value [NPV] = 0.57). Next, we assessed the ability of the model to predict MDS vs. Other for 52 additional independent subjects using the third pathologist's diagnosis to break any ties (Test Set 3). The classifier correctly predicted 15/21 MDS cases (PPV=0.83) and misclassified 6/31 Others as MDS (NPV=0.82). The overall accuracy was 83%. Conclusions: We identified that VAFs for 7 genes can correctly re-classify subjects as either MDS or Other in 74% of cases that were misclassified between local and central pathology review. Further assessment on an independent cohort showed an accuracy of 83% of the model. Taken together, these data suggest that complementing pathology reviews with targeted sequencing of 7 genes could improve MDS diagnosis. Disclosures Lindsley: MedImmune: Research Funding; Jazz Pharmaceuticals: Consultancy, Research Funding; Bluebird Bio: Consultancy; Takeda Pharmaceuticals: Consultancy. Bejar:Aptose Biosciences: Current Employment; AbbVie/Genentech: Honoraria; Astex/Otsuka: Honoraria; Takeda: Honoraria, Research Funding; Celgene/BMS: Honoraria, Research Funding; Daiichi-Sankyo: Honoraria; Forty-Seven/Gilead: Honoraria; Genoptix/NeoGenomics: Honoraria. DeZern:MEI: Consultancy; Astex: Research Funding; Abbvie: Consultancy; Celgene: Consultancy, Honoraria. Foran:H3Biosciences: Research Funding; Aptose: Research Funding; Kura Oncology: Research Funding; Trillium: Research Funding; Takeda: Research Funding; Revolution Medicine: Consultancy; Xencor: Research Funding; Agios: Honoraria, Research Funding; Aprea: Research Funding; Actinium: Research Funding; Servier: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Abbvie: Research Funding; BMS: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Boehringer Ingelheim: Research Funding. Gore:Abbvie: Consultancy, Honoraria, Research Funding. Komrokji:Acceleron: Honoraria; Incyte: Honoraria; Abbvie: Honoraria; Agios: Speakers Bureau; BMS: Honoraria, Speakers Bureau; Jazz: Honoraria, Speakers Bureau; Geron: Honoraria; Novartis: Honoraria. Maciejewski:Alexion, BMS: Speakers Bureau; Novartis, Roche: Consultancy, Honoraria. Padron:Novartis: Honoraria; BMS: Research Funding; Incyte: Research Funding; Kura: Research Funding. Starczynowski:Captor Therapeutics: Consultancy; Tolero Therapeutics: Research Funding; Kurome Therapeutics: Consultancy, Current equity holder in private company, Research Funding. Sekeres:BMS: Consultancy; Takeda/Millenium: Consultancy; Pfizer: Consultancy.