Kay, Neil E.

Abstract Introduction We have previously developed a primary human bone marrow model in CLL which allows us to study marrow derived mesenchymal stroma cells (MSC) and mimic in vivoMSC-leukemic interactions in CLL (Ding, Blood, 2010) These interactions proved to be bidirectional with functional implications for both cell types. However the biologic and clinical implications of these bilateral cellular interactions in relation to MSC function in CLL patients have not been completely studied. MSC are clearly established as an essential component in forming supportive marrow niches for hematopoiesis. Our focus in this study thus was to further investigate on the status of CLL MSC function in comparison with normal MSC and the impact of the leukemic CLL B cell on MSC function and its role in forming marrow niches in CLL. Methods Bone marrow (BM) aspirates of CLL patients or normal age-matched subjects were used to generate MSC and these MSC were then assessed for various functions. Specifically we assessed the growth, differentiation capacity, gene expression, cytokine secretion profile and transcriptome analysis of CLL and normal MSC using colony forming unit (CFU) assay, MSC differentiation assay, Affymetrix U133 2.0 plus array and RNA sequencing respectively. To determine MSC CFU frequency, fixed number of nucleated cells (5 or 10 million) from BM aspirates were added in MSC growth medium for 10 days to form CFU. CFU frequency was then calculated by dividing the number of MSC colonies by the fixed number of inputted nucleated cells. In order to test the specific gene changes that occurred in MSC after their interaction with CLL leukemic cells, normal MSC were co-cultured with CLL cells for 1 week and subsequently followed by cell growth, gene expression analysis with RNA sequencing and cytokine profiles using a multiplex assay. Results CLL MSC generated significantly lower CFU colonies compared to normal subjects (CLL [n=24] vs normal [n=6] mean: 2.2 vs. 22 CFU per million nucleated cells, p=0.01). In order to test if the lower number of CLL MSC CFU was due to their reduced growth capacity or lower frequency, we then performed the CFU assay using identical numbers of CLL and normal MSC at the start of culture. CLL MSC was found to have significantly lower CFU capacity compared to normal MSC (mean: 2.1 [CLL] vs 4.5 [normal] CFU/10 input cell, n=7 in each group, p=0.03). To investigate the mechanism(s) for the reduced growth capacity of CLL MSC, we compared the gene expression profiles of non-stimulated CLL vs. normal MSC (n=10 for each group) with the following outcomes: CLL MSC had increased expression of cell cycle inhibitor: p16(Ink4a) and p57, both key markers of cell senescence (Baker, Nature, 2011); CLL MSC overexpressed homeobox B cluster of transcription factors, key regulator for cell development and differentiation. Wnt inhibitors DKK1/DKK2 and non-canonical Wnt 5b known to be associated with aging were found to be 10 and 2 fold more elevated in CLL MSC. In addition, MSC abundantly produced a milieu of the cytokines MCP-1/IL-8/IL-6/IL-1Ra after interaction with CLL leukemic cells. These cytokines are associated with a senescent associated secretory phenotype (SASP). Co-culture experiments of normal MSC with CLL Leukemic cells revealed significant impact of leukemic cells on normal MSC functions. Co-culture with a low density of CLL leukemic cells (CLL to MSC ratio: ≤10,000/1) increased MSC growth (1.2 fold). However, high density co-culture of CLL cells with MSC (CLL to MSC ratio of 100,000/1) inhibited MSC growth (0.8 fold). Transcriptome analysis of normal MSC before and after one week of co-culture with CLL leukemic cells showed that normal MSC had alteration of ~1500 genes. Many of the modified genes (CDKN2B, DKK2, LIF, HGF, FOXQ1 etc) are known to be involved in regulation of cell growth and senescence. Conclusion Collectively, these results demonstrated that bone marrow derived CLL MSC have decreased proliferative potential and possess senescent phenotypes. Importantly these senescent features were inducible in normal MSC after their interaction with CLL leukemic cells implying that leukemic B cells can educate MSC to become senescent. The implications of the CLL MSC senescence status are multiple and include: defective hematopoietic niches due to dysfunctional MSC, immune dysregulation and the enhanced nurturing of CLL B cell by these MSC. We are now investigating several of these latter features in our current work. Disclosures Shanafelt: Genentech: Research Funding; GlaxoSmithKline: Research Funding; Celegene: Research Funding; Cephalon: Research Funding; Pharmacyclics/Jannsen: Research Funding; Hospira: Research Funding; Polyphenon E Int'l: Research Funding. Kay:Genetech: Research Funding; Pharmacyclics: Research Funding; Hospira: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees.

Abstract Introduction: The median age at diagnosis for CLL pts in the US is 72 years. As clinical trials in CLL have largely enrolled younger pt populations, data on disease and pts' characteristics, patterns of care, prognosis, and molecular features in aged CLL pts are limited. With this in mind, we conducted a prospective study to update critical demographic data and patterns of care for aged CLL pt. Patients and Methods: Connect®-CLL is a US-based prospective, longitudinal, multi-center, observational registry that is aimed at understanding patterns of CLL management without a study-specific intervention. We enrolled pts treated at an academic (n=155) or community (n=1340) setting between 2010 and 2014. Eligible pts were adults with a clinical diagnosis of CLL who required therapy 2 or less months after enrollment. Data on demographics, baseline characteristics, and treatment selection are presented here using descriptive statistics. Continuous variables are reported using appropriate measures of dispersion and central tendency (means, medians, ranges and standard deviations) while categorical variables are summarized as number and percentage of the analysis population. Results: Of 1495 enrolled pts, 457 (30.5%) were ≥75 years (57.3% males, 94.2% white). Rai stage III/IV was noted in 33% and B symptoms (predominantly fatigue (58.4%)) were observed in 68.1%. These and other clinical baseline characteristics appeared similar to pts younger than 75 years except that older pts had more prior malignancies (33.5% vs. 19.8%) and co-morbidities (69.3% vs. 53.6%). Cardiac, neurologic, and renal disorders were the most common morbidities in pts ≥75 years (11.5%, 8.8%, and 4.6% respectively). Imaging studies were performed in 157 (60.2%) older pts and in 416 (65.7%) pts less than 75 years prior to initial therapy. Percentage of pts with bulky nodes (> 5 cm) by imaging was similar in the two groups, 19.3% overall. Prognostic biomarker data were available on 247 pts (178 (72%) <75 years; 69 (28%) ≥75 years). While a higher proportion of older pts had CD38+ CLL (55.1% vs. 40.5%, P=0.038), the proportions of patients with ZAP-70+ CLL were similar between the two groups. In total, 137 (9%) older and 378 (25%) younger pts had 17p and 11q analysis by FISH at enrollment prior to first-line therapy. Of these, 27.0% of pts ≥75 years and 20.6% of pts <75 years had a deletion of either 17p or 11q (P=0.125). Out of all pts enrolled in the registry, 894 (60%) received first-line treatment (261 (29%) pts ≥75 years and 633 (71%) <75 years) as their indication for study entry. Amongst these treated pts, interim analysis shows (data cutoff date: 25 June 2014) progressive marrow failure was more commonly used as the indication for therapy in older pts compared to younger pts (52.1% vs. 38.5%; P<0.001), while splenomegaly was a more common cause for therapy in younger pts (16% vs. 9%; P<0.01). Rai stage III/IV at time of first therapy was 46% and 49% for younger and older pts, respectively. Progressive lymphocytosis was used as the indication for therapy in one third of pts regardless of age. Seventy-four percent of older CLL pts received first-line therapies containing rituximab (R) vs. 85% in pts <75 years (P<0.0001). R-bendamustine was the most common first-line regimen for CLL pts ≥75 (23.4%) while FCR was more commonly given to pts <75 years (32.5%). R-monotherapy was used in 18.8% of older pts versus 9.5% in pts <75 years (P<0.0001). Of note, approximately 25% of CLL pts ≥75 years did not receive R-based regimens for initial therapy. Conclusions: Connect®-CLL is the largest prospective, multicenter CLL registry in the United States. CLL Pts ≥75 years more frequently overexpress CD38 and may more commonly demonstrate high risk cytogenetics by FISH, although the difference did not reach statistical significance. Pts ≥75 years also more commonly had co-morbid diseases, and surprisingly 25% did not receive first-line R-based therapy. CLL pts are rarely included in front-line clinical trials (<3%). Given that novel therapies are increasingly available for CLL patients a continued analysis is warranted to determine their use in elderly vs younger patients as well. A longer follow up is needed to evaluate the impact of these findings on outcomes. Disclosures Nabhan: Celgene: Honoraria, Research Funding. Off Label Use: Lenalidomide in CLL. Kay:Celgene: Research Funding. Mato:Genentech, Celgene, Millenium: Speakers Bureau. Grinblatt:Celgene: Honoraria, Speakers Bureau. Kipps:Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Lamanna:Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Weiss:Celgene: Consultancy. Flinn:Celgene: Research Funding. Swern:Celgene: Employment, Equity Ownership. Street:Celgene: Employment, Equity Ownership. Kristen:Celgene: Employment, Equity Ownership. Flowers:Celgene, Prescription Solutions, Seattle Genetics, Millennium (unpaid), Genentech (unpaid) : Consultancy; Gilead, Spectrum, Millennium, Janssen: Research Funding.

Abstract BACKGROUND: Although chemoimmunotherapy (CIT) has improved response rates, treatment free survival, and overall survival in patients with chronic lymphocytic leukemia (CLL), only 40-50% of patients achieve a complete remission and the majority have residual disease when evaluated using sensitive assays. Interactions with nurturing environments can enhance CLL B-cell resistance to apoptosis. These interactions include cytokine mediated prosurvival signals by angiogenic molecules, such as VEGF and bFGF that nurture CLL B-cells in an autocrine fashion and promote CLL cell survival partly through up regulation of anti-apoptotic proteins. These findings provide a strong rationale for testing anti-VEGF therapy in combination with a purine nucleoside analogue CIT regimen for upfront treatment. We conducted a randomized phase 2 CIT trial using pentostatin, cyclophosphamide, and rituximab with (PCR-B) or without (PCR) bevacizumab (B), an anti-VEGF monoclonal anti-body. METHODS: Eligible patients were previously untreated and had CLL in need of treatment by NCI-WG criteria (Blood 111:5446). Patients were randomized using a dynamic allocation procedure stratifying for stage (0-II vs. III-IV) and FISH (17p or 11q deletion vs. other) to receive either 6 cycles of rituximab (100 mg on day 1 of cycle 1; 375 mg/m2on day 2 of cycle 1 and day 1 of cycles 2-6) followed by pentostatin (2 mg/m2) and cyclophosphamide (600 mg/m2) (PCR) administered every 21 days. Patients in the PCR-B cohort also received bevacizumab 15mg/kg on day 1 of cycles 1-5 and days 1, 22, & 43 of cycle 6. All patients underwent complete response evaluation 3 months after day 1 of cycle 6 (or last cycle of treatment for those completing < 6 cycles). MRD was assessed using 6-color flow cytometry (Leukemia 21:956) at the completion of treatment. RESULTS: 68 patients were enrolled through the Mayo Clinic Cancer Research Consortium between 1/2009 and 1/2013. Three patients were excluded from analysis: 1 patient canceled prior to treatment, 1 was dosed incorrectly, and 1 was ineligible due to immunophenotyping inconsistent with CLL. Median age of eligible patients was 63 years (range 43-81) and 43 (66%) were men. With respect to disease stage, 3 (5%), 38 (58%), and 24 (37%) had low, intermediate and high Rai stage disease. Eleven (17%) patients had deletion 17p or 11q & 29 (45%) had unmutated IGHV. No statistically significant differences were observed in these variables by treatment arm. All 65 evaluable patients have completed active treatment, with 54 (83.1%) completing the intended 6 cycles (PCR group 27/32 [84.4%] and PCR-B 27/33 [81.8%]). Hematologic grade 3+ adverse events deemed at least possibly related to treatment were observed in 10 (31.3%) patients on PCR and 12 (36.4%) on PCR-B (p=0.79). Non-hematologic grade 3+ adverse events deemed at least possibly related to treatment were observed in 9 (28.1%) patients on PCR and 18 (54.4%) on PCR-B (p=0.04). The most common such events were hypertension (PCR: 3.1% vs. PCR-B: 21.2%), proteinuria (0% vs. 6.1%) and creatinine increase (3.1% vs. 6.1%). Across both arms, 64/65 (98.5%) patients achieved a response including 31/32 (96.9%) treated with PCR and 33/33 (100%) treated with PCR-B (p=0.49). CR/CRi was achieved in 10/32 (31.3%) patients treated with PCR & 18/33 (54.5%) treated with PCR-B (p=0.08). Of the 28 who achieved a CR/CRi, MRD analysis was completed on 26, of whom 12 (46%) were MRD negative. With respect to treatment arm, 5/32 (16%) patients on PCR and 7/33 (21%) on PCR-B achieved an MRD negative CR. Median time to retreatment for all 65 patients was 44.8 (95% CI: 34.6 – NA) months. Median overall survival has not yet been reached. With current follow-up no differences between treatment-free survival (p=0.38), progression-free survival (p=0.23), or overall survival (p=0.45) are observed by treatment arm. Plasma levels of angiogenic cytokines VEGF, bFGF, thrombospondin (TSP) and the chemokines CCL3 and CCL4 were measured prior to treatment and at the time of the post treatment response evaluation. Correlations of these cytokines with clinical outcome will be presented. CONCLUSION: The addition of bevacizumab to purine analogue-based CIT was generally well-tolerated and may increase complete remission rates in patients with CLL. No clear improvement in treatment free survival has been observed to date. Disclosures Shanafelt: Hospiria: Research Funding; Pharmacyclics/Jannsen: Research Funding; Cephalon: Research Funding; Celgene: Research Funding; glaxoSmithKline: Research Funding; Genetech: Research Funding; Polyphenon E Int'l: Research Funding. Off Label Use: Off label use of pentostatin for treatment of CLL. Off label use of bevacizumab for treatment of CLL. . Kay:Genetech: Research Funding; Pharmacyclics: Research Funding; Hospira: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees.

Abstract Introduction: B-cell chronic lymphocytic leukemia (CLL) is an incurable disease despite that still requires options for treatment despite recent advances with BTK therapy. We previously found that Axl receptor tyrosine kinase (RTK), a member of the TAM (Tyro3, Axl, MER) family of RTKs, plays a critical role in CLL B-cell survival (Blood 2011, 117:1928). Here, we explored the levels of apoptosis induction of CLL B-cells using a novel high-affinity Axl inhibitor as a single agent or in combination with BTK inhibitors. Methods: Expression/activation status of the Tyro3, Axl and MER in CLL B-cells was evaluated by Immunoprecipitation/Western blots. Cells were treated with a high-affinity orally bioavailable Axl inhibitor TP-0903 (Tolero Pharmaceuticals) or FGFR inhibitor TKI-258 (Novartis) with or without the presence of CLL bone marrow stromal cells (BMSCs). Impact of Axl or FGFR signal inhibition on CLL B-cell survival was also evaluated by flow cytometry after staining with annexin V/propidium iodide. Finally, cells were exposed to TP-0903 in combination with BTK inhibitors to determine any synergistic/additive effects of the combination in induction of apoptosis. Combination index (CI) of two agents was calculated using the method of Chou and Talalay, 1984. Results: Although we defined pro-survival role of Axl in CLL B-cells, contribution of other members of the TAM family of RTKs including Tyro3 and MER to prolonged survival of the leukemic B-cells remains largely undefined. In this study we found that CLL B-cells overexpress Tyro3, but not MER, and that Tyro3 is constitutively phosphorylated. Interestingly, immunoprecipitation of Tyro3 from CLL B-cell lysates shows retention of highly active Axl in the immune complex suggesting that these two RTKs either heterodimerize or form a molecular complex in CLL B-cells. Our earlier work found that Axl regulates multiple cell survival signaling pathways including PI3K/AKT and Src and that, Axl inhibition using a first generation Axl inhibitor induced apoptosis in CLL B-cells (Blood 2011, 117:1928). Thus, we hypothesized that targeting Axl using a very high affinity Axl inhibitor would induce even higher levels of apoptosis in CLL B-cells compared to the first generation Axl inhibitor. To address this, we utilized a high-affinity orally bioavailable Axl inhibitor TP-0903 to generate preliminary information on its efficiency to specifically target Axl and the level of apoptosis induction in CLL B-cells. Indeed TP-0903 as a single agent induced a robust apoptotic cell death in CLL B-cells within 24 hours of exposure at nanomolar doses, which are easily achievable in vivo (information provided by Tolero Pharmaceuticals). Interestingly, while TP-0903 effectively reduces phosphorylation on Axl in CLL B-cells, it was unable to target P-Tyro3 suggesting that Axl is likely the predominant RTK of the TAM family in CLL B-cells. A marked reduction of the anti-apoptotic proteins Mcl-1, Bcl-2, XIAP and upregulation of the pro-apoptotic protein BIM in CLL B-cells via activation of its upstream regulator FOXO3a were noted as a result of inhibition of P-Axl and its downstream signaling pathways, P-AKT/P-Src. Importantly, TP-0903 was able to overcome CLL BMSC mediated protection of the leukemic B-cells from apoptosis induction. Given the observed robust induction of apoptosis with TP-0903 and the known impact of BTK inhibitors on CLL patient clinical outcome, we then exposed CLL B-cells to TP-0903 in combination with two BTK inhibitors that included Ibrutinib and a reversible BTK inhibitor TP-4216 (a kind gift from Tolero Pharmaceuticals). Based on the CI values, we found that the in vitro combination of TP-0903 and Ibrutinib showed additive effects in CLL B-cells from 6 of 11 CLL patients, CLL B-cells from the remaining 5 CLL patients showed antagonistic effects (Fig. 1A). However, we observed synergistic effects of TP-0903 in combination with TP-4216 in the induction of apoptosis in CLL B-cells from 2 of 10 patients and additive effects in CLL B-cells from 6 patients (Fig. 1B). Cells from the remaining 2 patients exhibited a slightly antagonisticeffect. Conclusion: In total, these results suggest that TP-0903 is quite effective in inducing robust CLL B-cell apoptosis as a single agent even at a nanomolar concentration and its combination with the reversible BTK inhibitor TP-4216 could be an effective and unique strategy for the treatment of CLL patients. Figure 1 Figure 1. Disclosures Warner: Tolero Pharmaceuticals: Employment, Equity Ownership, Patents & Royalties. Bearss:Tolero Pharmaceuticals: Employment. Shanafelt:Genentech: Research Funding; GlaxoSmithKline: Research Funding; Celegene: Research Funding; Cephalon: Research Funding; Pharmacyclics/Jannsen: Research Funding; Hospira: Research Funding; Polyphenon E Int'l: Research Funding. Kay:Genetech: Research Funding; Pharmacyclics: Research Funding; Hospira: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees.

Key Points Early progression of disease within 2 years of initial therapy independently predicts inferior survival in CLL. Early progression of disease is a robust clinical end point and a useful posttreatment risk stratification tool.

Abstract Introduction: Our current understanding of CLL biology and optimal therapies is based on clinical trials that have largely enrolled White patient populations. Whether these findings are applicable to Hispanic or non-White patients is unknown but critical to evaluate given the growing numbers of minority patients in the U.S. While retrospective studies have suggested inferior outcomes in non-White patients, prospective data on these disparities are lacking. Patients and Methods: We utilized the Mayo Clinic CLL database to better understand variations in disease characteristics, molecular differences, and treatment selections between non-Hispanic White patients and those not in this category (referred to hereafter as “other race”). After excluding 49 patients with missing diagnosis date and another 490 patients with missing race and/or ethnicity, the remaining 4104 cases within the registry were included in the analysis. Comparisons by race were made using Chi-square or Wilcoxon rank sum tests for qualitative or quantitative variables, respectively. Overall survival (OS) was calculated from diagnosis until death or last known alive date; time to first treatment (TTFT) was calculated from diagnosis until treatment date or date last known to be untreated. OS and TTFT were displayed via Kaplan-Meier plots, and differences in OS and TTFT by race were calculated using log-rank statistics. Individuals who were enrolled in early intervention trials (n=61) were excluded from analyses involving treatment. Results: In total, 4104 CLL patients were identified: 4011 (97.7%) non-Hispanic Whites and 93 (2.3%) other races. Median age at CLL diagnosis was younger for other race patients (59 vs. 63 years; p=0.002), while gender and stage distributions were comparable between both groups. Serum β-2-microglobulin and absolute lymphocyte counts at diagnosis were similar but more other race patients had elevated LDH (29.5% vs. 16.1%; p=0.02). Cytogenetic data by FISH were available for 1884 non-Hispanic Whites and 46 other race patients; poor-risk cytogenetics (17p and/or 11q deletions) were present in 23.9% of other race and 13.5% of non-Hispanic White patients, respectively (p=0.04). No statistically significant differences were observed for CD38, ZAP-70, or IGHV by race TTFT was similar for both non-Hispanic Whites and other race patients (4.6 vs. 5.5 years, respectively; p=0.12). First-line treatment selection was similar for both groups (Table). . With a median follow-up of 12.1 years, median overall survival was 9.3 years for other race and 12.2 years in non-Hispanic White patients (P=0.15; Figure). Conclusions: This prospective data supports the notion that CLL might be biologically different between non-Hispanic White and other race patients with less favorable FISH present in the latter group. Despite the observation that TTFT and type of first therapy are similar between both groups, the trend towards shorter OS in other race patients argues that other factors might contribute to outcome differences, such as disease biology, access to care, co-morbidities, and socioeconomic considerations. Further studies with larger cohorts are warranted. Table: First-line treatment selection among treated individual by racial First-line Treatment Non-Hispanic Whites(n=1875) Other race(n=41) Chemoimmunotherapy Purine analogue-based Alkylator-based 675 (36.0) 495 (26.4) 180 (9.6) 15 (35.6) 9 (22.0) 6 (14.6) Purine analogue -monotherapy 157 (8.4) 4 (9.8) Alkylator monotherapy 610 (32.5) 9 (22.0) PA+Alkylator 41 (2.2) 1 (2.4) Antibody alone 190 (10.1) 6 (14.6) Other 202 (10.8) 6 (14.6) Figure: Overall survival in CLL cases stratified by race Figure:. Overall survival in CLL cases stratified by race Disclosures Nabhan: Genentech: Honoraria, Research Funding, Speakers Bureau; Celgene: Honoraria, Research Funding; Janssen: Honoraria, Speakers Bureau. Kay:Celgene: Research Funding. Shanafelt:Genentech: Research Funding; GlaxoSmithKline: Research Funding; Celegene: Research Funding; Cephalon: Research Funding; Pharmacyclics/Jannsen: Research Funding; Hospira: Research Funding; Polyphenon E Int'l: Research Funding.

Abstract Introduction: Several B-cell malignancies, including chronic lymphocytic leukemia (CLL) and multiple myeloma (MM), are known to have a familial component to disease risk. Although several common inherited genetic variants have been found to be associated with risk of these malignancies, a large proportion of the heritability remains unexplained. Here we set out to identify rare high-penetrance susceptibility variants for CLL and MM using the established Mayo Clinic family study of B-cell malignancies. Methods: We performed exome sequencing on germ line DNA of 106 families with either two or more members with CLL (n=93 families) or two or more members with MM or monoclonal gammopathy of undetermined significance (MGUS) (n=13 families) using Aglient capture kits. All samples were sequenced on an Illumina HiSeq2000. Bioinformatics analyses leveraged the following software packages: Novoalign, Picard, The Genome Analysis Toolkit (GATK), and the Biological Reference Repository (bioR). Quality control filters were implemented; subjects with mis-specified relationships were removed as were variants with <95% call rate or <20x coverage, and those variants identified as sequencing artifacts. To identify potentially functional single nucleotide variants, the following was required a) uncommon in public databases, b) cosegregating variants in multiple families, c) variants to be highly conserved and in coding regions, and d) functional prediction status of deleterious (SIFT score), damaging (PolyPhen score), and a moderate, or high variant impact (SNPEffect). The association of these variants with risk was then evaluated in large samples of cases and controls in genome-wide association studies (GWAS). Results: In the CLL familial cohort, there were 443 individuals (160 with CLL, 73 with monoclonal B cell lymphocytosis (MBL), and 210 relatives without CLL or MBL) sequenced; and in the MM cohort, there were 39 individuals (13 with MM, 13 with MGUS and 13 without MM or MGUS) sequenced. A total of 61,992 single nucleotide variants passed quality control filters in the CLL cohort and 39,456 single nucleotide variants in the MM cohort. From these, we identified 32 variants in the CLL cohort and 39 variants in the MM cohort that were cosegregating in multiple CLL or MM families, respectively, and were predicted to affect protein structure or function. Of these, one CLL variant was within 1 Mb of a known GWAS-discovered locus. Moreover, there were seven CLL and four MM variants that were within 1 Mb of single nucleotide polymorphisms (SNPs) that had statistical significance between p<10-4 and p<10-6 in GWAS. Finally, there were 3 variants found to be common between CLL and MM families (see Table). Conclusions: Through whole exome sequencing, we identified a number of rare, highly penetrant predisposition variants for CLL and MM. Several of these variants were common to both B-cell malignancies providing evidence of shared genetic components; one variant may be a functional driver of the GWAS-discovered loci. These identified variants provide a list for future validation studies. Table: Exome variants common in both Chronic Lymphocytic Leukemia and Multiple Myeloma SNP ID rs41314099 rs61754114 rs143025033 Chromosome 17 6 7 Gene WSCD1 BACH2 TNS3 Penetrance (CLL) 0.70 0.75 0.80 Penetrance (MM) 1.00 0.80 0.75 Allele Frequency (CLL) 0.015 0.025 0.017 Allele Frequency (MM) 0.077 0.077 0.058 1000 Genome Frequency (European) 0.010 0.020 0.010 SIFT Term Deleterious Deleterious Deleterious PolyPhen Term Probably Damaging Probably Damaging Probably Damaging SNP: Single Nucleotide Polymorphism; CLL: Chronic Lymphocytic Leukemia; MM: Multiple Myeloma; Penetrance is defined as proportion of individuals carrying the alternate allele that are also affected; SIFT: Sorting Intolerant From Tolerant, predicts whether an amino acid substitution affects protein function; PolyPhen: Polymorphism Phenotyping, predicts possible impact of an amino acid substitution on the structure of a human protein Disclosures No relevant conflicts of interest to declare.

Abstract Although multiple myeloma is clinically defined as the accumulation of clonal, malignant plasma cells in the bone marrow, the disease shows significant heterogeneity with regard to morphology, progression and therapeutic response. Our hypothesis is that this heterogeneity likely is due, in part, to germline genetic polymorphisms that contribute significantly to an individual’s disease course and response. In particular, individuals deficient in the repair of DNA damage are not only at high risk for developing cancer, but also could show DNA repair dependent responses associated with DNA damaging therapeutic agents. In this study we examined the association of functional genetic polymorphisms in the DNA repair genes, XRCC1 (SNP positions 280, 399) and ERCC2 (SNP positions 312, 751), with toxicities and clinical outcomes in the ECOG, 3 arm chemotherapeutic trial, E9486 [A-VBMCP, B-VBMCP+Cylophosphamide, C- VBMCP+interferon]. DNA from 359 patients was genotyped and examined for association with response, toxicities, blood counts, bone pathology, and survival parameters. Notably, in the interferon arm of the trial significant associations were observed in progression free survival and polymorphisms of XRCC399 (AA median survival 51 months versus AG/GG median survival of 33 months; p=,008), ERCC751 (AA/AC median survival 33 months versus CC median survival of 48 months; p=.05), and ERCC312 (AA median survival 49 months versus AG/GG median survival of 34 months; p=.02). Hazard ratios ranged form 1.7 to 2.05 for survival differences associated with DNA repair genes in this arm. Interestingly, T cell counts are known to be impacted by interferon; and DNA repair polymorphisms in this arm were also associated with CD8+ T cell counts. While this represents a single arm of one clinical trial, it is intriguing to consider the impact of genetic polymorphisms on DNA repair in light of chemotherapeutic agents that may affect cells of the immune system. Previous studies from the ECOG Myeloma Committee of the E9486 trial show highly significant associations of survival and immune status in myeloma patients. Our results suggest genetic polymorphisms in DNA repair genes may influence clinical outcome in certain therapeutic regimens. Genetic polymorphisms in these DNA repair genes are currently being completed in 800 patients of the SW9321 SWOG/ECOG intergroup trial and additional association studies will be included in the presentation.

AbstractRecent analyses of circulating blood B cells in myeloma have generated controversy concerning the exact levels of these cells and whether they may represent circulating clonal tumor B cells. Previous reports suggested that CD19+ B cells are markedly increased in myeloma patients and that this population shares clonotypic rearrangements with the malignant plasma cell. We studied the numbers of CD19+ B cells by flow cytometry in previously untreated newly diagnosed myeloma patients in Eastern Cooperative Oncology Group (ECOG) phase III trial E9486. There were 628 patients who were eligible for the clinical protocol E9486, but of these 521 were also entered on the companion laboratory study (E9487) and had CD19 data. In comparison with normal controls, the myeloma patients exhibited a marked heterogeneity in the number of circulating CD19+ B cells as detected by flow cytometry. Approximately 20% of patients had significantly increased levels of circulating CD19+ B cells. However, the total CD19+ blood population from myeloma was not significantly different from the median of age-matched, normal controls. Analysis of CD19+ blood cells in relationship to circulating clonal cells was done in 13 myeloma patients using a clonotypic, quantitative allele-specific oligonucleotide-polymerase chain reaction (PCR) assay. No correlation was found between the numbers of CD19+ B cells (range, 5% to 51%) and PCR estimates of the number of clonal cells in the peripheral blood (range, .009% to 3.6%). Low CD19+ B-cell level (&lt;125 μL) was associated with clinical stage III (P = .033). A significant relationship exists between higher levels (≥125/μL) of CD19 cells and longer overall survival (P &lt; .0001). In addition, high CD19 levels also predicted a clinical response and longer event-free survival. There was a strong inverse association between the level of CD19 values at diagnosis and infections within the first 2 months of diagnosis. Importantly, the number of deaths related to infections was significantly greater in the low versus high CD19 group (P &lt; .0202). Also, CD19 is an independent prognostic factor in addition to plasma cell labeling indices, β2 -microglobulin, hemoglobin, and plasmablastic morphology. Patients with infections were more likely to have low levels of CD19+ cells. In summary, higher CD19+ cell levels are a favorable prognostic sign with no apparent relationship to circulating tumor cells. In addition, this analysis strongly suggests that low peripheral blood levels of CD19+ cells are an adverse prognostic sign in myeloma. The CD19+ cell levels in myeloma patients is an important parameter in the overall assessment of these patients.

Abstract The majority of pts with newly diagnosed CLL are classified with Rai stage 0 or 1 disease and typically experience an indolent clinical course. However, little is known regarding the reasons for initiating therapy in this population or patterns of initial treatment in the contemporary era of our practicing community. We utilized data from the Connect CLL registry, a US-based multi-center, prospective observational cohort study that is aimed at understanding patterns of CLL management without a study-specific intervention. Eligible pts were adults with a clinical diagnosis of CLL who initiated therapy ≤2 months prior to enrollment, and were enrolled from academic (n=155), community (n=1311), or government (n=28) sites between 2010-2014. Descriptive statistics were applied to examine data on demographics, baseline characteristics, treatment selection, early treatment outcomes, and reasons for initiating therapy that were reported for pts with Rai 0/1 CLL receiving first-line therapy. Multivariable logistic regression models were constructed to evaluate predictors of complete response (CR) and event-free survival (EFS) defined as the occurrence of the first of disease progression, relapse or death within 24 months of enrollment. Among 684 pts who received first-line therapy at enrollment and for whom Rai stage was available, 363 had Rai 0/1 CLL. This group had a median age of 68 years (range 41-90); 94% were white, 60% male, 98% insured, and 93% were treated in community practices; 47% had Rai stage 0 disease (54% Binet A); 33% had ≥1 constitutional symptoms; 96% had ECOG performance status of 0 or 1; 35% had conventional cytogenetics and 53% had FISH analysis performed. Among pts for whom cytogenetic or FISH analysis were performed, 159 (72%) were abnormal, of them 37 pts (23%) had del(11q), 104 pts (65%) had del(13q), 33 pts (21%) had trisomy 12, and 20 pts (13%) had del(17p) by conventional cytogenetics and/or FISH, including 8% with del(17p) by FISH. The median time from diagnosis to initiation of therapy was 2.5 years (range 0-20 years) for Rai 0/1 pts compared with 0.5 years for pts enrolled with Rai stage ≥2 (range 0-32). The most common reasons for initiating therapy (with >1 reason possible) in Rai 0/1 CLL were: bulky or progressive or lymphadenopathy (40%), progressive lymphocytosis (39%), any disease-related symptom (weight loss, fatigue, fever, night sweats; 28%), anemia (20%), and thrombocytopenia (15%); 42% of pts had >1 reason for initiation. The most common first-line regimens used in this cohort were: fludarabine/cyclophosphamide/rituximab (FCR; 29%), bendamustine/rituximab (BR; 20%), and rituximab alone (12%). Of the 317 pts who either responded to treatment during the first 24 months of enrollment or were followed ≥24 months, 143 pts (45%) achieved CR (investigator assessed as per protocol) and 264 (83%) achieved CR or partial response. Female gender (odds ratio [OR] = 2.22), treatment with BR or FCR (OR = 3.41), and time from diagnosis to therapy (OR = 0.92; with each year increase in time from diagnosis to initiation of therapy, relative odds of CR decreases by 8%), were independent predictors of CR. Of the 311 evaluable pts, 82 pts (26%) experienced an EFS event during the 24 months on study, of which 19 (23%) were deaths and 48 (59%) were progressions. Age ≥75 years (OR = 4.46), lymphocytosis as a reason for therapy initiation (OR = 1.89), and male gender (OR = 1.73) were independent predictors of an EFS event within 24 months. The Connect CLL registry represents the largest comprehensive prospective cohort of CLL pts collected from multiple practices across the US. In concordance with other studies, pts with Rai 0/1 initiated therapy approximately 2.5 years following CLL diagnosis and included a cohort of pts with poor prognostic FISH characteristics. Although chemoimmunotherapy was associated with a significantly higher likelihood of CR, progressive lymphocytosis as a reason for initiating therapy (and not any form of treatment) was more likely to predict an early EFS event. Approaches using novel agents or combination therapies aimed towards addressing pts with progressive lymphocytosis should be considered in future studies. Disclosures Flowers: Seattle Genetics: Consultancy; OptumRx: Consultancy; AbbVie: Research Funding; Pharmacyclics: Research Funding; Gilead Sciences: Research Funding; Genentech: Research Funding; AbbVie: Research Funding; Celegene: Other: Unpaid consultant, Research Funding; Spectrum: Research Funding; Onyx Pharmaceuticals: Research Funding; Spectrum: Research Funding; Acerta: Research Funding; Gilead Sciences: Research Funding; Janssen: Research Funding; Infinity Pharmaceuticals: Research Funding; Infinity Pharmaceuticals: Research Funding; Janssen: Research Funding; Millennium/Takeda: Research Funding; Onyx Pharmaceuticals: Research Funding; Pharmacyclics: Research Funding; Acerta: Research Funding; Millennium/Takeda: Research Funding. Nabhan:Celgene Corporation: Honoraria, Research Funding. Kay:Pharmacyclics: Research Funding; Genentech: Research Funding; Celgene Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding; Hospira: Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees, Research Funding; Tolero Pharma: Research Funding. Mato:AbbVie: Consultancy, Research Funding; Janssen: Consultancy; Celgene Corporation: Consultancy, Research Funding; Pronai Pharmaceuticals: Research Funding; Pharmacyclics: Consultancy, Research Funding; TG Therapeutics: Research Funding; Gilead: Consultancy, Research Funding; Genentech: Consultancy. Lamanna:Genentech-Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene Corporation: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Infinity: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Grinblatt:Celgene Corporation: Consultancy, Honoraria, Speakers Bureau. Kipps:Pharmacyclics Abbvie Celgene Genentech Astra Zeneca Gilead Sciences: Other: Advisor; Pharmacyclics Abbvie Celgene Genentech Astra Zeneca Gilead Sciences: Other: Advisor. Kozloff:Roche: Consultancy, Speakers Bureau; Celgene: Consultancy, Speakers Bureau; Genentech: Consultancy, Speakers Bureau; AbbVie: Consultancy. Sullivan:Celgene Corporation: Employment, Equity Ownership. Flick:Celgene Corporation: Employment, Equity Ownership. Kiselev:Celgene Corporation: Consultancy. Bhushan:Celgene Corporation: Employment, Equity Ownership. Swern:Celgene Corporation: Employment, Equity Ownership. Sharman:TG Therapeutics, Inc.: Research Funding; Gilead: Consultancy, Honoraria, Research Funding, Speakers Bureau; Janssen: Research Funding; Calistoga: Honoraria; Celgene Corporation: Consultancy, Research Funding; Pharmacyclics: Consultancy, Honoraria, Research Funding; Roche: Research Funding.