ALBERT

Description: Several gene-expression signatures predict survival in diffuse large B-cell lymphoma (DLBCL), but the lack of practical methods for genome-scale analysis has limited translation to clinical practice. We built and validated a simple model using one gene expressed by tumor cells and another expressed by host immune cells, assessing added prognostic value to the clinical International Prognostic Index (IPI). LIM domain only 2 (LMO2) was validated as an independent predictor of survival and the “germinal center B cell–like” subtype. Expression of tumor necrosis factor receptor superfamily member 9 (TNFRSF9) from the DLBCL microenvironment was the best gene in bivariate combination with LMO2. Study of TNFRSF9 tissue expression in 95 patients with DLBCL showed expression limited to infiltrating T cells. A model integrating these 2 genes was independent of “cell-of-origin” classification, “stromal signatures,” IPI, and added to the predictive power of the IPI. A composite score integrating these genes with IPI performed well in 3 independent cohorts of 545 DLBCL patients, as well as in a simple assay of routine formalin-fixed specimens from a new validation cohort of 147 patients with DLBCL. We conclude that the measurement of a single gene expressed by tumor cells (LMO2) and a single gene expressed by the immune microenvironment (TNFRSF9) powerfully predicts overall survival in patients with DLBCL.

Description: BACKGROUND: Mantle cell lymphoma is characterized by short remissions and a median overall survival (OS) of less than 6 years with standard chemotherapy. We previously reported results of a single-arm phase II clinical trial of intensive chemotherapy induction with R-MACLO-IVAM followed by thalidomide maintenance with promising progression-free survival (PFS) and OS (Lossos et al. Leuk Lymph 2010). A subsequent single-arm phase II clinical trial assessing rituximab (R) rather than thalidomide maintenance was conducted and preliminary data communicated (Hosein et al. Am J Hematol 2015). We now present the final results of these studies. METHODS: Two prospective single-arm phase II clinical trials conducted at the University of Miami were IRB approved. Eligible patients were chemotherapy-naïve with confirmed diagnosis of MCL using WHO criteria, age 18-75 years, ECOG PS: 0-2, adequate organ function and no history of HIV or prior cancer. Pretreatment staging included CT and PET scans, colonoscopy and bone marrow biopsy. The chemotherapy regimen has been previously described (Lossos et al. Leuk Lymph 2010). Patients who achieved complete responses (both radiologically and pathologically) were eligible for the maintenance phase. Between June 2004 and 2019, 44 patients were enrolled; the first 22 patients received maintenance therapy with thalidomide (200 mg daily until relapse/intolerable toxicity) and a subsequent cohort of 22 patients received R (375mg/m2 IV weekly x 4 weeks, repeated every 6 months for 3 years). OS was calculated from date of diagnosis to date of death or last follow up, and PFS from date of diagnosis to the date of pathological evidence of recurrence or death. Analysis was performed using the Kaplan-Meier method, and the log-rank or Wilcoxon test for group comparison. RESULTS: Median PFS in thalidomide and R cohorts were 7.8 and 8.1 years, and 10-year OS 63.6% and 57.8%, respectively. There was no statistically significant PFS or OS difference between patients treated with thalidomide or R maintenance (Wilcoxon p= 0.988 and p= 0.564, respectively). Therefore, all 44 patients were evaluable together for toxicity and 43 for response. Median age was 58 (range 39-73 years), most patients were males (35, 79.5%) and ECOG PS ≤ 1 (42, 95.5%). All patients had at least stage III disease, with bone marrow involvement in 38 (86.4%), gastrointestinal involvement in 23 out of 39 (59%), and elevated LDH in 14 (68.2%) patients. Ki67 was 〉30% in 20 (54.1%) and blastic variant in 6 (13.6%) patients. Most patients presented with IPI ≥ 3 (23, 52.3%) and intermediate-high MIPI (30, 68.1%) scores. 36 completed all 4 cycles of therapy, treatment was stopped in 6 after 3 cycles, and in 1 after 2 cycles. 1 patient died during the first cycle. Of the 43 patients completing 2 cycles of chemotherapy 41 (95.3%) achieved complete response (CR) and 2 (4.7%) partial response (PR). There were 23 (52.3%) events for PFS (19 relapses, 4 deaths without documented progression/relapse), and 14 (31.8%) total deaths over a median follow up of 6.7 years (range 1-15). The 5 and 10-year PFS were 54.9% (95%CI: 37.6-69.2%) and 39.2% (95%CI: 22.3-55.8%), respectively; median PFS 8 years (95%CI: 3.9-12.5 years). 5 and 10-year OS were 84.4% (95%CI: 68.4-92.7%) and 60.4% (95%CI: 41.2-75.1%), respectively; and median OS was not reached. PFS and OS were statistically significant shorter in the high-risk MIPI group than intermediate and low groups (5-year PFS rates: 23.1% vs. 53.8% vs. 92.9%, respectively, p

Description: Background: DLBCL is the most common adult NHL and despite significant advancements, outcomes in ethnic minorities remain suboptimal. Factors responsible for these disparities in ethnic minorities, especially variability in clinical and pathological features with evaluation of patient-level data have not been studied. Methods: A multi-institutional database of DLBCL patients seen at Mayo Clinic in Florida, University of Miami and University of Southern California between 1996-2016 was developed. Patient demographics, clinical disease characteristics and details of DLBCL immunophenotype [CD10, MUM1, BCL6 (Han's classification), Ki 67, MYC, BCL2) were reviewed. Comparisons between Hispanic and Non-Hispanic patients were made by Chi-square, Fischer's exact and Signed rank tests, where applicable. Patients with missing data on a certain feature were not included in the statistical analysis of that specific characteristic. Results: A total of 966 DLBCL patients with 69 Hispanics and 752 non-Hispanics were identified. These included 52% males (N=36) and 48% females (N=33) in Hispanics versus 58% males (N=436) and 42% females (N=316) in Non-Hispanics (p=0.35). Median age at diagnosis was significantly lower at 61 years (range 27-89) in Hispanics versus 66 in non-Hispanics (p=0.014). Extranodal disease was seen significantly more commonly in Hispanics (74%) than in non-Hispanics (60%) (p=0.037). There was no significant difference in disease stage at presentation between the two cohorts (p=0.189) although the proportion of patients with stage III and IV disease was higher among Hispanics (80.4%) as compared to non-Hispanics (68.5%). Similarly there was no significant difference in presence of primary CNS DLBCL at diagnosis between the two groups (p=0.74). GCB phenotype per the Hans' classification was seen in 59% (N=29) in both, Hispanics and Non-Hispanics (N=241) (p=0.99). Similarly, the median ki67 index of 80% was seen in both cohorts (p=0.48). MYC was positive in 59% in Hispanics versus only 37.5% in non-Hispanics (p=0.024). BCL2 expression by itself and also combined BCL2 and MYC double expression were not significantly different between the two groups (p=0.58 and p=0.11, respectively). Median overall survival (OS) was 22.5 months in Hispanics compared 54.9 months in Non-Hispanics (p

Description: Abstract 622 Background: Several gene-expression signatures are predictive of prognosis in diffuse large-B-cell lymphoma (DLBCL), but the lack of practical methods for a genome-scale analysis has restricted their routine clinical applicability. Methods: We studied genes whose expression had been reported to predict survival in DLBCL, attempting to validate genes and prognostic models with robust survival associations that are amenable to rapid diagnostic testing. Results: Among a previously described set of 6-genes shown to predict survival independent of measurement platform or therapy era (Lossos, et al. 2004 NEJM 350:1828), we identified LMO2 as the single gene with strongest independent prognostic value in 3 independent cohorts of patients with DLBCL. To assess the independent contribution of other genes in predicting survival, using existing microarray gene expression data (Lenz, et al. 2008 NEJM 359:2313), we evaluated all pairwise models that included LMO2 toward construction of a robust bivariate survival predictor. Among 54674 possible models, one combining expression of LMO2 with TNFRSF9 (encoding 4-1BB, also known as CD137) emerged as among the best in cross-validation when assessed in training (n=233) and test (n=181) cohorts. This bivariate predictor remained prognostic in both CHOP (p=1.7e-6) and R-CHOP (p=6.5e-8) therapy eras, was highly independent of the International Prognostic Index, Cell-of-Origin classification, 6-gene predictive model, ‘stromal' model, and added significantly to their prognostic power. While LMO2 expression was highly restricted to tumor cells and was linked to Cell-of-Origin (GCB, p=2.2e-16), TNFRSF9 expression was highest in non-tumor cells (P=0.02), particularly in an activated subset of infiltrating CD8 T-cells. To validate this bivariate model and devise a practical diagnostic assay, we used quantitative real-time polymerase-chain-reaction to measure the expression of LMO2 and TNFRSF9 as well as other components of the 6-gene model (BCL2, BCL6, FN1, CCL3, and CCND2) in diagnostic formalin fixed and paraffin-embedded samples of lymphoma from an independent set of 147 patients with de novo DLBCL treated with R-CHOP. The IPI distribution for these patients was: 0-1 factor (n=70), 2 factors (n=40), 3 factors (n=26), ≥4 factors (n=11). In univariate and multivariate analyses of this independent cohort, LMO2 and TNFRSF9 expression remained individually prognostic of both progression free and overall survival. The bivariate model combining LMO2/TNFRSF9 could be used to stratify distinct risk groups for overall survival (p=0.004), and remained independent of IPI. Conclusion: Measurement of the expression of two genes integrating contributions of tumor cells and the tumor microenvironment is sufficient to predict overall survival in patients with DLBCL treated with R-CHOP. Disclosures: Advani: Seattle Genetics, Inc.: Research Funding.

Description: Abstract 2006 Background: Several gene expression signatures predict survival in diffuse large B cell lymphoma (DLBCL), but the lack of practical methods for genome scale analysis has limited translation to clinical practice. Methods: We examined the power of individual genes to predict survival across different therapeutic eras. In studying 787 patients with DLBCL, we built and validated a simple model employing one gene expressed by tumor cells and another expressed by host immune cells, assessing added prognostic value to the clinical International Prognostic Index (IPI). We validated models in an independent cohort using diagnostic formalin-fixed specimens. Results: We verified expression of LMO2 as an independent predictor of survival and ‘Germinal Center B-cell’ subtype. We identified expression of TNFRSF9 from the tumor microenvironment, as the best in bivariate combination with LMO2. We studied distribution of TNFRSF9 tissue expression in 95 patients. A model integrating these two genes (TGS) was independent of ‘cell of origin’ classification, ‘stromal signatures’, IPI, and added to the predictive power of the IPI. This bivariate model and a composite score integrating the IPI (TGS-IPI) performed well in three independent cohorts of 545 previously described patients. Both models robustly stratified outcomes in a simple assay of routine specimens from 147 newly diagnosed patients as depicted. Conclusion: Measurement of a single gene expressed by tumor cells (LMO2) and a single gene expressed by the immune microenvironment (TNFRSF9) powerfully predicts overall survival in patients with DLBCL. A simple test integrating these two genes with the IPI can readily be used to select patients of different risk groups for clinical trials. Disclosures: No relevant conflicts of interest to declare.

Description: Abstract 624 Background: Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease with a variable clinical outcome even in the current era of rituximab containing anthracycline-based chemotherapy (RCHOP). We have previously reported a 6 gene model which is predictive for outcome in DLBCL (Lossos et al NEJM 2004, 350:1829 and Malumbres et al Blood 2008, 111:5509). Recently, short non-protein coding microRNAs (miRNA) that regulate gene expression by targeting the 3'UTR region of mRNA have been identified and are postulated to play an important role in oncogenesis. We have previously demonstrated that miRNAs exhibit specific expressions at different lymphocyte differentiation stages as well as distinct expression in gene expression-defined DLBCL subtypes (Malumbres et al Blood 2009; 113:3754). Herein, we evaluated whether specific miRNAs differentially expressed across DLBCL cell lines were prognostic biomarkers for prediction of outcome of DLBCL patients (pts). Patients and Methods: RNA was extracted from paraffin-embedded archived specimens (Chen et al Diagn Mol Pathol 2007, 16:61), from pts with newly diagnosed de novo DLBCL treated with R-CHOP at 4 different institutions. Expression of 11 miRNAs, including miR-146a, miR-146b-5p, miR-222, miR-500, miR-574-3p, miR-363, miR-155, and miR-21 that are differentially expressed between the ABC and GCB DLBCL subtypes, as well as expression of miR-18a, miR-140-3p, and miR-181a which has been reported to be variably expressed across DLBCL tumors were analyzed by ABI real-time PCR assays. Expression of the genes comprising the 6 gene survival prediction model were measured as reported previously. Expression was correlated to progression-free survival (PFS) and overall survival (OS). Predictive value of miRNAs was evaluated both as a continuous variable as well as a in a dichotomous model with pts grouped based on miRNA median expression. Results: The study group consisted of 176 pts with a median age 59 years (y) (range 16-92) of which 84 pts (48%) were 〉 60 y. 54 pts (30%) had an ECOG PS ≥2 and 86 (49%) presented with stage III or IV. Distribution according to the IPI was: 0-1 factor (n=77); 2 factors (n=50); 3 factors (n=30); and ≥4 factors (n=19). There were 41 deaths during a median follow-up of 2.6 years (range 0.04-8.1y). OS correlated with expression of miR-18a as a continuous variable, with higher expression correlating with inferior OS (p=0.038) but was not independent of the IPI in a multivariate model. PFS correlated with expression of miR-181a as a continuous variable (p=0.026; higher expression associated with longer PFS) and with expression of miR-222 as a categorical variable (miR-222cat; p=0.004, lower expression associated with longer PFS). In a multivariable model including IPI, both miR-222cat and miR-181a were IPI independent (p=0.01 and p=0.003, respectively). The mortality-prediction score calculated from the 6-gene model predicted both the OS (p=0.007) and PFS (p=0.004) and was IPI-independent. A multivariate Cox regression analysis that included IPI scores, mortality predictor scores and expression of miR-18a, miR-181a and miR-222cat revealed that all factors except miR-222cat were independent predictors of OS and all factors except miR-18a were independent predictors of PFS. Conclusions: We confirm that in RCHOP treated pts with DLBCL the 6-gene model predicts both OS and PFS independent of the IPI. Expression of miRNAs miR-18a, miR-181a and miR-222 is associated with response to therapy and outcome of pts with DLBCL, independent of the IPI and the mortality-prediction score calculated from the 6-gene model. While the expression of miR-181a and miR-222 may reflect the cell of origin of DLBCL tumors, the expression of miR-18a does not. Further studies are warranted to evaluate the precise role of these miRNAs in B-cell biology and DLBCL pathogenesis and prognosis. Disclosures: Advani: Seattle Genetics, Inc.: Research Funding.

Description: Alemtuzumab is a monoclonal antibody to CD52 that has activity in T-cell leukemia and lymphoma. This study aims to describe the complications and outcomes of a subset of patients with mycosis fungoides/Sézary syndrome who were treated with alemtuzumab. Four of 8 patients, with no prior history of cardiac problems, developed significant cardiac toxicity (congestive heart failure or arrhythmia) that mostly improved after alemtuzumab discontinuation. The role of this agent in potentially inducing important cardiac side effects is suggested and argues for further investigation.

Description: Background: Covalent BTK inhibitors (BTKi) have transformed the management of MCL, WM, and MZL. Despite the marked efficacy of covalent BTKi, treatment failure can occur through the development of resistance and discontinuation for adverse events. Covalent BTKi also share pharmacologic liabilities (e.g. low oral bioavailability, short half-life) that may lead to suboptimal BTK target coverage, for example in rapidly proliferating tumors with high BTK protein turnover, ultimately manifesting as acquired resistance in some patients (pts). To address these limitations, LOXO-305, a highly selective, non-covalent BTKi that inhibits both wild type (WT) and C481-mutated BTK with equal low nM potency was developed. The aim of the BRUIN trial was to define the safety and early efficacy of LOXO-305 in pts with B-cell malignancies. Here we report these data in pts with previously treated MCL, WM, and other NHLs. Methods: BRUIN is a multicenter phase 1/2 trial (NCT 03740529) enrolling pts with advanced B-cell malignancies who have received 〉2 prior therapies. Dose was escalated according to a standard 3+3 design with LOXO-305 dosed orally in 28-day cycles. The primary endpoint was MTD/RP2D identification. Intra-patient dose-escalation to previously cleared dose levels was permitted. Efficacy evaluable pts included all dosed pts who underwent their first response evaluation or discontinued therapy. Response was assessed every 8 weeks from cycle 3, and every 12 weeks from cycle 13 and was measured according to Lugano Classification or iWWM. Safety was assessed in all pts (CLL/SLL and NHL, n=186). Results: As of 30 April 2020, 186 pts with B-cell malignancies (94 CLL/SLL, 38 MCL, 19 DLBCL, 17 WM, 6 FL, 5 MZL, and 7 Other [B-PLL and Richter's transformation]) were treated on 7 dose levels (25mg to 300mg QD). Among the 92 pts with NHL, the median age was 68 (range 27-87) years. Median number of prior lines of therapy was 2 for MCL (range 2-8), and 3 for other NHLs (range 2-11). 92% of MCL pts had received a prior BTKi; 87% received at least an anti-CD20 antibody, chemotherapy, and BTKi; 10 pts had received SCT/CAR-T; 71% of WM pts had received a prior BTKi. LOXO-305 demonstrated high oral exposures, with doses ≥100mg QD exceeding the BTK IC90 for the entirety of the dosing interval. There were no DLTs or dose reductions. Consistent with LOXO-305's selectivity, the only treatment emergent adverse events regardless of attribution or grade seen in 〉10% of pts (n=186) were fatigue (n=29, 16%) and diarrhea (n=28, 15%). Responses were observed at the first dose level of 25mg QD. A RP2D of 200mg QD was selected for future studies. At the efficacy cutoff date, 24 MCL pts (63%) and 35 other NHL pts (65%) remained on therapy. Among the 35 efficacy-evaluable MCL pts treated across all dose levels, the ORR was 51% including 9 CRs, 9 PRs, 7 SDs, 8 PDs, and 2 NEs. An additional 3 MCL pts were awaiting initial radiologic assessment. Among the subset of 20 efficacy evaluable MCL pts who started at the RP2D (200mg QD), the ORR was 65% including 7 CRs, 6 PR, 4 SDs, 1 PD and 2 NEs. Of the 18 responding pts treated at any dose, all except 2 remain on therapy, with the longest followed responding pt on treatment for 14 months and ongoing. Of the 2 responding pts who have discontinued treatment, 1 progressed and 1 achieved a CR and electively discontinued treatment to undergo allogeneic stem cell transplant. Responses in MCL have been observed in pts who received prior cell therapy, including 3 of 7 patents with prior SCT, and 1 of 2 with prior CAR-T. Among the 15 efficacy-evaluable pts with WM, the ORR was 60% (1 VGPR, 4 PRs, 4 MRs, 5 SDs, 1 NE), and also 60% in the subset with prior BTKi treatment. 8 of 9 WM responders were ongoing (follow-up time from initial response: 0.1-4.8 months). For the remaining 29 efficacy-evaluable other NHL pts, best response was as follows: DLBCL (3 CRs, 1 SD, 6 PDs, 5 NEs), FL (3 PRs, 1 SD, 1 PD), MZL (2 PRs, 1 SD) and Other [5 Richter's transformation, 1 B-PLL] (2 PRs, 2 SDs, 2 NEs). Conclusion: LOXO-305 demonstrated promising efficacy in heavily pretreated, poor-prognosis MCL pts following multiple prior lines of therapy, including covalent BTKi. Early efficacy was also observed in BTK-treated WM, as well as heavily pretreated other NHLs. LOXO-305 was well tolerated and exhibited a wide therapeutic index. Disclosures Wang: Kite Pharma: Consultancy, Other: Travel, accommodation, expenses, Research Funding; Loxo Oncology: Consultancy, Research Funding; Verastem: Research Funding; Molecular Templates: Research Funding; Dava Oncology: Honoraria; InnoCare: Consultancy; Oncternal: Consultancy, Research Funding; Nobel Insights: Consultancy; VelosBio: Research Funding; OMI: Honoraria, Other: Travel, accommodation, expenses; Celgene: Consultancy, Other: Travel, accommodation, expenses, Research Funding; AstraZeneca: Consultancy, Honoraria, Other: Travel, accommodation, expenses, Research Funding; Janssen: Consultancy, Honoraria, Other: Travel, accommodation, expenses, Research Funding; Pharmacyclics: Consultancy, Honoraria, Other: Travel, accommodation, expenses, Research Funding; Targeted Oncology: Honoraria; Juno: Consultancy, Research Funding; BioInvent: Research Funding; Lu Daopei Medical Group: Honoraria; OncLive: Honoraria; Beijing Medical Award Foundation: Honoraria; MoreHealth: Consultancy; Guidepoint Global: Consultancy; Acerta Pharma: Research Funding; Pulse Biosciences: Consultancy. Shah:Cell Vault: Research Funding; Miltenyi Biotec: Honoraria, Research Funding; Celgene: Consultancy, Honoraria; Incyte: Consultancy; Lily: Consultancy, Honoraria; Kite Pharma: Consultancy, Honoraria; Verastim: Consultancy; TG Therapeutics: Consultancy. Alencar:Genentech, Celgene, KITE, Loxo Oncology at Lilly: Consultancy. Gerson:Loxo: Research Funding; Pharmacyclics: Consultancy; Abbvie: Consultancy; Genentech: Consultancy. Fakhri:University of California San Francisco: Current Employment. Jurczak:MeiPharma: Research Funding; Roche: Research Funding; Takeda: Research Funding; Jagiellonian University, Krakow, Poland: Ended employment in the past 24 months; Pharmacyclics: Research Funding; Bayer: Research Funding; Janssen: Research Funding; Acerta: Research Funding; TG Therapeutics: Research Funding; Maria Sklodowska-Curie National Research Institute of Oncology, Krakow, Poland: Current Employment. Tan:Sir Charles Gairdner Hospital and Linear Clinical Research: Current Employment. Lewis:Sir Charles Gairdner Hospital and Linear Clinical Research: Current Employment. Fenske:Medical College of Wisconsin: Current Employment. Coombs:Novartis: Honoraria; Octapharma: Honoraria; LOXO Oncology: Honoraria; MEI Pharma: Honoraria; AstraZeneca: Honoraria; Genentech: Honoraria; Abbvie: Consultancy, Honoraria. Flinn:Calithera Biosciences: Research Funding; Loxo: Research Funding; IGM Biosciences: Research Funding; Takeda: Consultancy, Research Funding; Genentech, Inc.: Research Funding; F. Hoffmann-La Roche: Research Funding; Gilead Sciences: Consultancy, Research Funding; Agios: Research Funding; Karyopharm Therapeutics: Research Funding; Incyte: Research Funding; BeiGene: Consultancy, Research Funding; AstraZeneca: Consultancy, Research Funding; TG Therapeutics: Consultancy, Research Funding; Curio Science: Consultancy; MorphoSys: Consultancy, Research Funding; Curis: Research Funding; Nurix Therapeutics: Consultancy; Novartis: Research Funding; Pfizer: Research Funding; Pharmacyclics LLC, an AbbVie Company: Consultancy, Research Funding; Portola Pharmaceuticals: Research Funding; Seattle Genetics: Consultancy, Research Funding; Teva: Research Funding; Constellation Pharmaceuticals: Research Funding; Great Point Partners: Consultancy; Forma Therapeutics: Research Funding; Iksuda Therapeutics: Consultancy; Unum Therapeutics: Consultancy, Research Funding; Juno Therapeutics: Consultancy, Research Funding; Infinity Pharmaceuticals: Research Funding; Acerta Pharma: Research Funding; AbbVie: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Trillium Therapeutics: Research Funding; Triphase Research & Development Corp.: Research Funding; Verastem: Consultancy, Research Funding; Yingli Pharmaceuticals ≠: Consultancy, Research Funding; Rhizen Pharmaceuticals: Research Funding; Johnson & Johnson: Other; Roche: Consultancy, Research Funding; Vincera Pharma: Consultancy; Merck: Research Funding; Celgene: Research Funding; ArQule: Research Funding; Kite Pharma: Consultancy, Research Funding; Forty Seven: Research Funding. Le Gouill:Loxo Oncology at Lilly: Consultancy; Roche Genentech, Janssen-Cilag and Abbvie, Celgene, Jazz pharmaceutical, Gilead-kite, Loxo, Daiichi-Sankyo and Servier: Honoraria. Palomba:Celgene: Honoraria; Pharmacyclics: Honoraria; Genentech: Research Funding; Novartis: Honoraria; Merck: Honoraria; Juno Therapeutics, a Bristol-Meyers Squibb Company: Honoraria, Research Funding; Regeneron: Research Funding. Woyach:Janssen, Pharmacyclics, AstraZeneca, Abbvie, Arqule: Consultancy; Pharmacyclics, Janssen, Morphosys, Karyopharm, Verastem, Abbvie, Lox: Research Funding; Pharmacyclics LLC, an AbbVie Company, AbbVie, Janssen, AstraZeneca, ArQule: Honoraria. Lamanna:Columbia University Medical Center: Current Employment; MingSight: Other: Institutional research grants, Research Funding; Octapharma: Research Funding; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees; Bei-Gene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Institutional research grants, Research Funding; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Astra Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Institutional research grants, Research Funding; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Institutional research grants, Research Funding; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Juno: Other: Institutional research grants, Research Funding; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Institutional research grants, Research Funding; Loxo: Research Funding; Oncternal, Verastem, TG Therapeutics: Other: Institutional research grants, Research Funding. Cohen:Genentech, BMS, Novartis, LAM, BioInvent, LRF, ASH, Astra Zeneca, Seattle Genetics: Research Funding; Janssen, Adicet, Astra Zeneca, Genentech, Aptitude Health, Cellectar, Kite/Gilead, Loxo: Consultancy. Ghia:Gilead: Consultancy, Honoraria, Research Funding; ArQule: Consultancy, Honoraria; Acerta/AstraZeneca: Consultancy, Honoraria; BeiGene: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding; Celgene/Juno: Consultancy, Honoraria; Lilly: Consultancy, Honoraria; MEI: Consultancy, Honoraria; Sunesis: Consultancy, Honoraria, Research Funding; Adaptive, Dynamo: Consultancy, Honoraria; Novartis: Research Funding; AbbVie: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding. Eyre:KITE, AZ, Loxo Oncology at Lilly: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Consultancy, Honoraria, Other: travel support; AbbVie: Consultancy, Honoraria, Other: travel support; Gilead: Consultancy, Honoraria, Other: travel support. Yin:Loxo Oncology at Lilly: Current Employment. Nair:Loxo Oncology at Lilly: Current Employment. Tsai:Loxo Oncology at Lilly: Current Employment. Ku:Loxo Oncology at Lilly: Current Employment. Mato:Pharmacyclics: Consultancy, Research Funding; TG Therapeutics: Consultancy, Research Funding; AstraZeneca: Consultancy, Research Funding; Adaptive: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Loxo: Consultancy, Research Funding; Genentech: Consultancy, Research Funding. Cheah:Celgene, F. Hoffmann-La Roche, MSD, Janssen, Gilead, Ascentage Pharma, Acerta, Loxo Oncology, TG therapeutics: Honoraria; Celgene, F. Hoffmann-La Roche, Abbvie, MSD: Research Funding.

Description: Background:Racial disparities in multiple myeloma (MM) outcomes are well established. Clinical characteristics and cytogenetic abnormalities dictate outcomes in MM but historically they have been mostly defined in White patients with paucity of information regarding racial-ethnic minorities. Hispanics are the fastest growing racial-ethnic subgroup in United States and have the worst overall survival (OS) in MM but differences in disease presentation among Hispanics compared to Whites, the historical control, are undefined. Methods: MM patients seen at Mayo Clinic in Florida (MCF) and Arizona (MCA) between 1/1/2000-06/15/2017 were included. Patient and disease characteristics including gender, age at diagnosis, bone marrow (BM) plasmacytosis, laboratory data [M spike, creatinine (Cr), beta-2-microglobulin (B2M), Hemoglobin (Hb), calcium (Ca)], MM subtype [IgG, IgA, light chain (LC), other], LC subtype (κ, λ, biclonal), presence of lytic bone lesions, disease stage (DS, ISS, R-ISS), mSMRT cytogenetic risk category, presence of individual cytogenetic mutations (deletions, translocations, gains, trisomy/hyperdiploidy) was collected. Comparisons between Hispanic study cohort characteristics and historical control were made by Chi-square, Fischer's exact and Signed rank tests, where applicable, using data from previous publications [Kyle et al, 2003 (n=1027) and Fonseca et al, 2003 (n=351)]. Patients with missing data on a certain clinical or disease feature were not included in the statistical analysis of that specific characteristic. Results: A total of 1705 MM patients were screened and 266 Hispanic patients seen at either site between the specified dates were identified for the analysis. These included equal number of males and females (n=133 each) with a median age of 58 years (range 25-87). IgG disease was seen in 52% with IgA and LC subtypes in 23% each. LC subtype was κ in 67%, λ in 31% and biclonal in 2% cases. Lytic and extramedullary disease were noted in 71% and 44% patients, respectively. DS and R-ISS stage at the time of MM diagnosis was not available in most patients while ISS stage among 150 patients showed stage 1, 2 and 3 in 48%, 28% and 24% patients, respectively. mSMART risk categories were present in 226 patients and included high, intermediate and standard risk in 12%, 11% and 77% patients, respectively. Of these 226 patients, cytogenetic disease prior to starting any MM treatment was available in 153 patients with similar risk category distribution. Median follow up for the whole Hispanic cohort was 38.6 months with a median OS 10.7 years (Figure 1). Comparison with historical control datasets which were 97% or greater comprised of White patients showed some significant differences for the Hispanic cohort including gender distribution, median age, BM plasmacytosis at the time of diagnosis, median Hb, Cr or M spike at presentation, light chain subtype, presence of lytic bone disease and certain cytogenetic alterations including t(4;14) and del13q/monosomy (Table 1). We did not note differences in high-risk cytogenetics between Hispanics and historical White controls. Conclusions: We report the first description of clinical and cytogenetic characteristics of Hispanic MM patients. The current and historical datasets that we have used are all from Mayo Clinic experience, thus making reasonable comparisons possible. We were able to confirm previous reports of demographic differences in Hispanics e.g., younger age at diagnosis. While some characteristics were significantly different, the clinical and cytogenetic differences we note do not clearly explain the inferior OS noted for Hispanics in population-based studies. Significant differences that we report warrant continued exploration in larger institutional and public databases in addition to a continued look into healthcare access and utilization. An ongoing collaborative analysis with data from Mayo Clinic, University of Miami and University of Southern California, Los Angeles is ongoing. Disclosures Fonseca: AMGEN: Consultancy; Jansen: Consultancy; Mayo Clinic & Dr Fonseca: Patents & Royalties: Prognostication of myeloma via FISH, ~$2000/year; Celgene Corporation: Consultancy, Research Funding; Merck: Consultancy; Adaptive Biotechnologies: Membership on an entity's Board of Directors or advisory committees; Bayer: Consultancy; Bristol-Myers Squibb: Consultancy; Takeda: Consultancy; Sanofi: Consultancy; Pharmacyclics: Consultancy; Novartis: Consultancy. Kelly: Pharmacyclics: Honoraria; Abbvie: Honoraria; Amgen: Honoraria; Jannsen: Honoraria. Sher: LAM Therapeutics, Inc: Research Funding. Ailawadhi: Pharmacyclics: Research Funding; Takeda: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Novartis: Consultancy, Honoraria.

Description: Background: Covalent BTK inhibitors (BTKi) have transformed the management of CLL/SLL. Despite the marked efficacy of covalent BTKi, treatment failure can occur through the development of resistance and discontinuation for adverse events. The activity of covalent BTK inhibitors is markedly reduced or absent in the presence of BTK cysteine binding site (C481) mutations. Moreover, these agents share pharmacologic liabilities (e.g. low oral bioavailability, short half-life) that may lead to suboptimal BTK target coverage, for example in rapidly proliferating tumors with high BTK protein turnover, ultimately manifesting as acquired resistance in some patients (pts). To address these limitations, LOXO-305, a highly selective, non-covalent BTKi that inhibits both wild type (WT) and C481-mutated BTK with equal low nM potency was developed. The aim of the BRUIN trial was to define the safety and early efficacy of LOXO-305 in pts with B-cell malignancies. Here we report these data in pts with previously treated CLL/SLL. Methods: BRUIN is a multicenter phase 1/2 trial (NCT 03740529) enrolling pts with advanced B-cell malignancies who have received 〉2 prior therapies. Dose was escalated according to a standard 3+3 design with LOXO-305 dosed orally in 28-day cycles. The primary endpoint was MTD/RP2D identification. Intra-patient dose-escalation to previously cleared dose levels was permitted. Efficacy evaluable pts included all dosed pts who underwent their first response evaluation or discontinued therapy. Response was assessed every 8 weeks from cycle 3, and every 12 weeks from cycle 13 and was measured according to the iwCLL 2018 criteria, including PR with lymphocytosis (PR-L). Safety was assessed in all pts (CLL/SLL and NHL, n=186). Results: As of 30 April 2020, 186 pts with B-cell malignancies (94 CLL/SLL, 38 MCL, 19 DLBCL, 17 WM, 6 FL, 5 MZL, and 7 Other [B-PLL and Richter's transformation]) were treated on 7 dose levels (25mg to 300mg QD). Among the 94 pts with CLL/SLL, the median age was 69 (range 36-84) years and median number of prior therapies was 4 (range 1-10). 84% of CLL/SLL pts had received a prior BTKi, and 69% had received an anti-CD20 antibody, chemotherapy, and BTKi. In addition, 21% had received a PI3K inhibitor and 31% venetoclax. At enrollment, central molecular characterization for high-risk features in available samples revealed 17p deletion in 21% (13/63), TP53 mutation in 30% (27/91), and unmutated IGHV in 84% (51/61). LOXO-305 demonstrated high oral exposures, with doses ≥100mg QD exceeding the BTK IC90 for the entirety of the dosing interval. There were no DLTs or dose reductions. Consistent with LOXO-305's selectivity, the only treatment-emergent adverse events regardless of attribution or grade seen in 〉10% of pts (n=186) were fatigue (n=29, 16%) and diarrhea (n=28, 15%). Responses were observed at the first dose level of 25mg QD. A RP2D of 200mg QD was selected for future studies. At the efficacy cutoff date, 88 CLL/SLL pts (94%) remained on therapy and 65 CLL/SLL pts were efficacy-evaluable (58 BTKi-treated, 7 BTKi-naïve). Median follow up time was 3 months (range 0.1-13) for all pts and 6.7 months for responders. The ORR was 57%, with 23 PRs, 14 PR-Ls, 26 SDs, 1 PD, and 1 NE (Figure). An additional 29 pts were ongoing and awaiting initial radiologic assessment. As has been observed with covalent BTK inhibitors, responses deepened over time; among pts with at least 6 months of follow-up (n=26), the ORR was 77%. Response rate was not influenced by the presence or absence of a pretreatment BTK C481 mutation, the reason for prior BTKi discontinuation (i.e. progression vs intolerance), or other classes of prior therapy received (including a covalent BTK and BCL2 inhibitor). Of the 37 responding pts, all except 2 remain on therapy (1 progressed and 1 achieved a PR and electively discontinued treatment to undergo an allogeneic stem cell transplant). The longest-followed responding patient has been on treatment for 13.5 months and is ongoing. Responding pts with BTK C481 mutations demonstrated corresponding decreases in mutant disease burden by ddPCR. Conclusion: LOXO-305 demonstrated promising efficacy in heavily pretreated, poor-prognosis CLL/SLL pts following multiple prior lines of therapy including covalent BTKi and a BCL2 inhibitor. Importantly, the activity of LOXO-305 was not restricted to pts with BTK C481 mutations. LOXO-305 was well tolerated and exhibited a wide therapeutic index. Figure Disclosures Mato: Pharmacyclics LLC, an AbbVie Company: Consultancy, Research Funding; TG Therapeutics: Consultancy, Other: DSMB, Research Funding; Genentech: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; LOXO: Consultancy, Research Funding; BeiGene: Consultancy; AstraZeneca: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding; Adaptive: Consultancy, Research Funding. Coombs:Abbvie: Consultancy, Honoraria; Genentech: Honoraria; AstraZeneca: Honoraria; MEI Pharma: Honoraria; LOXO Oncology: Honoraria; Octapharma: Honoraria; Novartis: Honoraria. Shah:TG Therapeutics: Consultancy; Celgene: Consultancy, Honoraria; Incyte: Consultancy; Cell Vault: Research Funding; Kite Pharma: Consultancy, Honoraria; Miltenyi Biotec: Honoraria, Research Funding; Verastim: Consultancy; Lily: Consultancy, Honoraria. Lamanna:Oncternal, Verastem, TG Therapeutics: Other: Institutional research grants, Research Funding; MingSight: Other: Institutional research grants, Research Funding; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Institutional research grants, Research Funding; Columbia University Medical Center: Current Employment; Bei-Gene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Institutional research grants, Research Funding; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Astra Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Institutional research grants, Research Funding; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Institutional research grants, Research Funding; Loxo: Research Funding; Octapharma: Research Funding; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees; Juno: Other: Institutional research grants, Research Funding; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees. Lech-Marańda:Roche, Novartis, Takeda, Janssen-Cilag, Amgen, Gilead, AbbVie, Sanofi: Consultancy; Roche, Amgen, Gilead: Speakers Bureau. Eyre:Gilead: Consultancy, Honoraria, Other: travel support; Janssen: Consultancy, Honoraria, Other: travel support; KITE, AZ, Loxo Oncology at Lilly: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AbbVie: Consultancy, Honoraria, Other: travel support. Woyach:Janssen, Pharmacyclics, AstraZeneca, Abbvie, Arqule: Consultancy; Pharmacyclics, Janssen, Morphosys, Karyopharm, Verastem, Abbvie, Lox: Research Funding; Pharmacyclics LLC, an AbbVie Company, AbbVie, Janssen, AstraZeneca, ArQule: Honoraria. Cheah:Celgene, F. Hoffmann-La Roche, Abbvie, MSD: Research Funding; Celgene, F. Hoffmann-La Roche, MSD, Janssen, Gilead, Ascentage Pharma, Acerta, Loxo Oncology, TG therapeutics: Honoraria. Roeker:AbbVie: Other: spouse with minority ownership interest ; Abbott Laboratories: Other: spouse with minority ownership interest ; American Society of Hematology: Research Funding. Fakhri:University of California San Francisco: Current Employment. Tam:Janssen: Honoraria, Research Funding; Pharmacyclics LLC, an AbbVie Company: Honoraria; AbbVie: Honoraria, Research Funding; BeiGene: Honoraria, Research Funding. Gerson:Genentech: Consultancy; Pharmacyclics: Consultancy; Abbvie: Consultancy; Loxo: Research Funding. Alencar:Genentech, Celgene, KITE, Loxo Oncology at Lilly: Consultancy. Abdel-Wahab:Merck: Consultancy; Janssen: Consultancy; Envisagenics Inc.: Current equity holder in private company; H3 Biomedicine Inc.: Consultancy, Research Funding. Ghia:MEI: Consultancy, Honoraria; Lilly: Consultancy, Honoraria; Celgene/Juno: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding; BeiGene: Consultancy, Honoraria; Acerta/AstraZeneca: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding; Gilead: Consultancy, Honoraria, Research Funding; ArQule: Consultancy, Honoraria; Sunesis: Consultancy, Honoraria, Research Funding; Novartis: Research Funding; Adaptive, Dynamo: Consultancy, Honoraria. Schuster:Novartis, Genentech, Inc./ F. Hoffmann-La Roche: Research Funding; AlloGene, AstraZeneca, BeiGene, Genentech, Inc./ F. Hoffmann-La Roche, Juno/Celgene, Loxo Oncology, Nordic Nanovector, Novartis, Tessa Therapeutics: Consultancy, Honoraria. Chen:Loxo Oncology at Lilly: Current Employment. Nair:Loxo Oncology at Lilly: Current Employment. Tsai:Loxo Oncology at Lilly: Current Employment. Ku:Loxo Oncology at Lilly: Current Employment. Brown:Abbvie, Acerta, AstraZeneca, Beigene, Invectys, Juno/Celgene, Kite, Morphosys, Novartis, Octapharma, Pharmacyclics, Sunesis, TG Therapeutics, Verastem: Consultancy; Janssen, Teva: Speakers Bureau; Gilead, Loxo, Sun, Verastem: Research Funding. Jurczak:Bayer: Research Funding; Janssen: Research Funding; MeiPharma: Research Funding; Pharmacyclics: Research Funding; Roche: Research Funding; Takeda: Research Funding; TG Therapeutics: Research Funding; Acerta: Research Funding; Maria Sklodowska-Curie National Research Institute of Oncology, Krakow, Poland: Current Employment; Jagiellonian University, Krakow, Poland: Ended employment in the past 24 months.