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Abstract ROR1 is a type-1 tyrosine kinase-like orphan-receptor that ordinarily is expressed during embryogenesis, but that also is found on leukemia cells of patients (pts) with chronic lymphocytic leukemia (CLL). In prior studies we found ROR1 served as a receptor for Wnt5a, which could promote survival/growth of CLL cells. We found Wnt5a in the plasma is significantly higher in pts with CLL (3.2±1.6 ng/ml (mean ±S.D.), N = 36) than in healthy adults (0.14±0.16 ng/ml, N=14, p<0.01) and also may be elaborated by accessory cells in the CLL microenvironment. On the other hand, reducing expression of ROR1 on CLL cells via siRNA adversely affected leukemia-cell survival. We hypothesized that expression of ROR1 in CLL could play a role in the pathogenesis and/or progression of this disease. Early studies failed to define differences in the expression level of ROR1 on CLL cells of different pts in a small cohort. However, upon further analyses, we observed heterogeneity in the expression levels of ROR1 among samples of different pts in larger cohort. We investigated whether the level of ROR1 expression was associated with disease progression in a cohort of 1,568 CLL pts followed by CLL Research Corium (CRC). CLL samples were uniformly examined for the expression of ROR1 using the same preparation of an Alexa-647-conjugated anti-ROR1 mAb (4A5) and a standardized procedure by the CRC Tissue Core. We used 10 CLL cases, and tested ROR1 expression at 3 different time-points for each case. We found ROR1 expression was stable over time in all CLL cases. Then, we randomly segregated pt samples into either of two cohorts, one a training set of 797, and the other a validation set of 773 cases. For the 797 cases in the training dataset, we used the profile-likelihood method in a Cox regression model of treatment-free survival (TFS) from diagnosis to determine the optimal threshold level of ROR1 expressionthat could segregate pts into 2 subgroups. In the training cohort, 294 pts were stratified into a "ROR1-Low" subgroup and 503 pts were assigned to a "ROR1-High" subgroup, defining a threshold absolute mean fluorescence intensity of CLL cells stained for ROR1 of 29. The subgroup of pts in the ROR1- High subgroup had a median TFS of 6.0 years, whereas those pts in the ROR1-Low subgroup had a median TFS of 11.0 years. We applied this threshold to segregate the 773 samples of the validation cohort into ROR1-High and ROR1-Low subgroups. We found that high-level expression of ROR1retained its strong predictive adverse effect on TFS in this validation set. The subgroup of pts in the ROR1- High subgroup had a median TFS of 5.7 years, whereas those pts in the ROR1-Low subgroup had a median TFS of 11.8 years. The immunoglobulin heavy-chain variable region (IGHV) mutation status was known for 593 of the 797 samples in the training set (74%) and 586 of the 773 samples in the validation set (76%). A significantly lower percentage of the ROR1-Low cases (34%, or 69 of 203) used unmutated IGHV than did the ROR1-High cases (54%, or 209 of 390) (p<0.001). Nonetheless, using a multivariate Cox regression model with either a non-delayed entry or a delayed entry, we observed that high-level expression of ROR1 had predictive value for short TFS (non-delayed entry HR 1.4, p<0.05; delayed entry HR 1.9, p<0.001) even when the IGHV mutation status was taken into consideration (non-delayed entry HR 2.8, p<0.001; delayed entry HR 2.7, p<0.001). Taken together, this study demonstrates that there is heterogeneity in the expression of ROR1 on CLL B cells. Furthermore, we find that a high level expression of ROR1 is associated with early disease progression in pts with CLL. Table 1. Number of cases with high versus low ROR1 and mutated versus unmutated IGHV in the training and validation cohort Training Dataset Validation Dataset ROR1 MFI distribution (Median) 0~475 (35.5) 0~424(34.6) ROR1Low with Mutated IGHV 139 132 ROR1Low with Unmutated IGHV 64 84 ROR1High with Mutated IGHV 181 156 ROR1High with Unmutated IGHV 209 214 Total With Known IGHV Mutation Status 593 586 Disclosures Keating: Celgene Corp.: Consultancy; Glaxo-Smith-Kline Inc.: Other: Advisory board. Kay:Celgene Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics: Research Funding; Tolero Pharma: Research Funding; Genentech: Research Funding; Hospira: Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees, Research Funding. Byrd:Acerta Pharma BV: Research Funding. Gribben:Celgene: Consultancy, Honoraria; Janssen: Honoraria; Roche/Genentech: Honoraria; Pharmacyclics: Honoraria; Gilead: Honoraria. Kipps:Pharmacyclics Abbvie Celgene Genentech Astra Zeneca Gilead Sciences: Other: Advisor.

Abstract Abstract 3610 Purpose Chronic Lymphocytic Leukemia (CLL) is incurable with conventional chemotherapy treatments. Nurturing of leukemic CLL B cells by marrow microenvironment appears to be one important method of chemoresistance (NEJM 2005). Epigallocatechin 3 gallate (EGCG), the major catechin in green tea, induces caspase-dependent death CLL B-cells and down regulates anti-apoptotic proteins (Mcl-1; XIAP) critical for enhanced apoptosis resistance of CLL B-cells (Blood 2004). In Phase I and II clinical testing, we found EGCG induced a decline in absolute lymphocyte count and/or lymphadenopathy in the majority of Rai stage 0-II CLL patients (JCO 2009; ASCO 2010). In these phase I/II studies, trough plasma EGCG levels as high as 8 mM were achieved. Since it does not cause myelosuppression, EGCG has the potential to be combined with other chemotherapeutic agents used for CLL. We previously reported that pharmacologically achievable plasma levels of EGCG have an additive or synergistic effect when combined with fludarabine (F), chlorambucil (C), and FC in the majority of patients (ASH 2009). In this study, we evaluated i) the effect of pharmacologically achievable doses of EGCG when combined with bendamustine (B) and ii) the ability of pharmacologically achievable doses of EGCG to overcome in vitro stromal rescue of CLL B-cells exposed to B or FC. Methods We first evaluated the effects of EGCG combined with B to establish if this partnership would be additive or synergistic. Primary CLL cells were treated with B (12.5-100 mM) with or without 4 uM EGCG. After 48 hours cells were stained with annexin/PI, and viability analyzed by flow cytometry. Data were analyzed using the CalcuSyn program (Chou & Talay method) to determine the combination index (indicating antagonistic, additive or synergistic effects). Next, we evaluated the ability of 4 mM EGCG to overcome stromal rescue of CLL cells treated with B or FC. To eliminate the cytotoxic effects of FC and B on stromal cells, we treated CLL cells with FC or B for 24 hours, washed with PBS, and then cultured these drug exposed cells directly on the HS-5 human stromal cell line with or without 4 mM EGCG for 48 hours (FC) or 24 hours (B). Cells were harvested and viability of CD19+ cells was assessed by annexin/PI staining. To specifically evaluate the ability of 4 mM EGCG to overcome stromal protection, co-culture samples in which no stromal protection was observed were excluded. Similar experiments were conducted using primary bone marrow mesenchymal stromal cells (MSC) from CLL patients (Leuk Res, 2007). In these experiments the fludarabine/chlorambucil combination was used as an approximation of fludarabine/cyclophosphamide since the active form of cyclophosphamide (4-hydroxycyclophosphamide) rapidly breaks down in aqueous buffer and is not readily available for in vitro use and. Results We previously observed additive or synergistic FC and EGCG interactions in a majority of patient samples (ASH 2009). 4 mM EGCG was less consistently beneficial when combined with increasing doses of B in the absence of stroma. Synergistic or mixed synergistic/additive effect was seen in 5 patients, mixed additive/antagonistic effects in 3, and antagonistic effects in 2. Given previously observed synergy with FC and additive/synergistic interactions with at least some B treated samples, we next explored the effects of EGCG on stromal cell rescue. Co-culture with HS-5 stromal cells significantly reduced both B and FC mediated cell death. However the addition of 4 μM EGCG significantly attenuated stromal cell rescue of CLL B-cells exposed to B and FC therapy (Fig. 1A and 1B respectively). Remarkably in the case of FC, 4 mM EGCG almost completely abrogated stromal rescue. Experiments using primary bone marrow MSC cultures from CLL patients yields similar results (n=3, data not shown). Conclusions Pharmacologically achievable doses of EGCG appear to reduce stromal rescue of CLL cells treated with B or combinations of purine nucleoside analog/alkylating agents. This occurs in the absence of detectable stromal cell kill by EGCG. These findings, coupled with the favorable toxicity profile and lack of myelosuppression in phase I/II trials of EGCG make it an attractive agent to test in combination with bendamustine or purine analogue/alkylating agent chemo-immunotherapy for patients with CLL. Disclosures: Shanafelt: Polyphenon Pharma: Research Funding.

Abstract Abstract 4610 Introduction: Infections are a major cause of morbidity and mortality in patients with chronic lymphocytic leukemia (CLL). Up to 50% of patients with CLL will develop infectious complications during the course of their disease, and 30–50% of all deaths from CLL are attributed to infections and infectious complications. The risk of infection in CLL is related to immune deficiencies associated with the primary disease process, as well as immunosuppression secondary to treatment. Available research on infectious complications of CLL has focused on patients in clinical trials receiving chemotherapy. Little is known about the natural history of infection in community dwelling patients with newly diagnosed CLL. Method: To explore the natural history of infection in a local, community dwelling cohort of patients diagnosed with CLL, we used the Mayo Clinic CLL database to identify all patients with newly diagnosed CLL seen in the Mayo Clinic Division of Hematology after January 1, 1999 and who resided within 50 mi of Mayo Clinic (Rochester, MN). All patient hospitalizations were reviewed to document infection including cross-referencing with the electronic Mayo Clinic infection database which includes all culture and serology results obtained from hospitalized Mayo Clinic patients. Patients who had positive blood, sputum, cerebrospinal fluid, pleural fluid, or paracentesis fluid culture results were identified. Patients whose cultures were negative were considered to have culture negative infection. Serologies and viral assays (e.g. CMV viral load) were also reviewed to identify infections. Results: In May 2010, there were 2022 patients in the Mayo Clinic CLL Database with the diagnosis of CLL/SLL made between Jan 1999 – Dec 2009. Of these, 336 (17%) patients resided within a 50 mi radius of Mayo Clinic and were considered non-referred, community-based CLL patients. Median age at diagnosis for these 336 patients was 69 yrs (range 27–97) and most had early stage CLL (57% stage 0; 34% stage I-II). With respect to prognostic markers, 206 (70%) patients were CD38 negative, 125 (64%) ZAP-70 negative, 85 (53%) IgVH mutated, and 101 (63%) had either no abnormality or 13q14- as a sole abnormality on FISH analysis. Consistent with being a community dwelling cohort, ~90% (152/165) of patients had co-morbid health problems and ~50% (86/165) had a major comorbidity (e.g. coronary artery disease, cerebral vascular disease, CHF, diabetes, COPD, other malignancy). Although ~17% (43/249) of patients had gamma-globulin levels below the reference range at diagnosis, only 2% (6/249) had an IgG level <500 mg/dL. Median follow-up for all patients was 49 months (range 0–121) and 104 (31%) patients progressed to require treatment for CLL. Although 222 (66%) patients required hospitalization during follow-up, only 38 (11.3%) were hospitalized with infection. Collectively, these 38 patients were hospitalized for infection 139 times (median 2 hospitalizations for infection per patient). Among these 38 patients, 13 had no organism identified on cultures (culture negative infection) while the remaining 25 (66%) had an organism identified during at least hospitalization for infection. Of the 38 patients hospitalized with infection, 18/38 (47%) had a gram positive organism (8 strep pneumonia, 11 staphylococcus Aureus, 2 nocardia), 11/38 (29%) had a gram negative organism (3 E.Coli, 4 Pseudomonas, 4 Hemophilus influenzae), 5/38 (13%) a mycobacterial infection (4 MAC, 1 M. gordonae), 15/38 (40%) a cytomegalovirus infection, 19/38 (50%), cryptococcus and/or cryptosporidium (18 cryptococcus AG, 4 cryptosporidium), and 12/38 (32%) a filamentous fungi infections (12 aspergillous). In aggregate, hospitalization for an opportunistic infection (e.g. cytomegalovirus, cryptococcus, filamentous fungi, myocobacteria, pneumocystis) occurred in 26/336 (8%) CLL patients during follow-up. Being male (OR 2.7; p=0.02), ZAP-70+ (OR 3.9; p=0.004), IGHV unmutated (OR 5.5; p=0.002), and receiving treatment (OR 4.7, p<0.001; Figure) were associated with increased risk of hospitalization for infection. Conclusions: Approximately 8% of newly diagnosed, community dwelling CLL patients will require hospitalization for opportunistic infection at some point during the course of their disease. Gender, disease factors (e.g. ZAP-70, IGHV status), and treatment characteristics are associated with infection risk. Disclosures: Zent: Genzyme: Research Funding; Genentech: Research Funding; Novartis: Research Funding; G.S.K.: Research Funding. Shanafelt:Celgene: Research Funding; Hospira: Research Funding; Genentech: Research Funding.

Abstract Abstract 3452 Poster Board III-340 PURPOSE Chronic Lymphocytic Leukemia (CLL) is incurable with current chemotherapy treatments. Epigallocatechin 3 gallate (EGCG), the major catechin in green tea, has been shown to induced caspase-dependent death CLL B-cells and down regulate anti-apoptotic proteins (Mcl-1; XIAP) known to increase the resistance of CLL B-cells to apoptosis (Blood 104:788-94). In Phase I testing for patients with early stage CLL (Rai 0-II), EGCG treatment was well tolerated and induced a decline in absolute lymphocyte count (ALC) and/or lymphadenopathy in the majority of treated patients without myelosuppression (JCO 27:3808-14). Although peak plasma EGCG levels were not measured in this study, trough plasma EGCG levels as high as 4 μg/ML were achieved. To further our understanding of the potential clinical applications of EGCG for patients with CLL, we evaluated the effects of EGCG on the viability of CLL B-cells when combined with fludarabine (F), chlorambucil (C), or fludarabine and chlorambucil in combination (FC). METHODS Primary CLL B-cells were treated with various doses of F (0.25-1 μM), C (10-30 μM), or FC either alone or in combination EGCG (50 to 100 μM). In other experiments, CLL B-cells were treated with various doses of F (0.25-1 μM), C (10-30 μM), or FC with or without a fixed dose of EGCG known to be physiologically achievable in vivo (4 μM). After 48 hours (experiments with C +/− EGCG) or 72 hours (experiments with F +/− EGCG or FC +/− EGCG), cells were harvested, stained with annexin/PI and viability analyzed by flow cytometry. After concentration-effect curves were generated for each agent, data were also analyzed using the CalcuSyn software program (Biosoft, Cambridge, UK) which uses the method of Chou and Talalay to determine whether combination treatment yielded greater effects than expected from summation alone. A combination index (CI) of 0.8 – 1.2 indicates an additive effect, a CI >1.2 indicates an antagonistic effect and a CI <0.8 indicates a synergistic effect. RESULTS Primary leukemic B-cells from 56 CLL patients were cultured in vitro with various doses of EGCG alone or in combination with F, C, or FC. The median LD50 was approximately 100 μM. Although % apoptotic cells at the 100 μM EGCG dose did not vary based on Rai stage, ZAP-70 status, IGHV gene mutation status, or cytogenetic abnormalities by FISH, CD38 negative patients had greater cell death than CD38 positive patients (67% vs. 49%; p=0.05). In co-titration experiments, EGCG had an additive (CI 0.8 – 1.2) or synergistic (CI <0.8) effect on apoptosis when combined with C in the majority of patients (13/15; additive 11, synergism 2) with rare individuals demonstrating antagonism (CI >1.2; 2/15). The effects of EGCG when combined with F in co-titration experiments were more variable with a relatively even distribution between antagonism (8/18), additive effects (4/18), and synergy (6/18). However, co-titration experiments of FC with or without EGCG demonstrated additive or synergistic effect in most patients (8/10; additive 7, synergism 1). Next we evaluated the effect of F (0.25 - 1 μM), C (10 - 30 μM), or FC with or without a fixed dose of EGCG known to be physiologically achievable in vivo (4 μM). This dose of EGCG had an additive or synergistic effect in the majority of samples across the spectrum of dose levels under all 3 conditions (F, C, and FC). For example, at the 10 μM dose of C the addition of 4 μM EGCG had an additive or synergistic effect in 11/14 patients (synergistic 6; additive 5). With F at the 2.5 μM dose level the addition of 4 μM EGCG had an additive or synergistic effect in 13/16 patients (synergistic 7, additive 6). The addition of 4 μM EGCG appeared particularly beneficial when given in combination with FC (Fig.). For example, at F 2.5 μM in combination with C 5 μM the addition of 4 μM EGCG had an additive or synergistic effect in 10/10 patients (synergism 7; additive 3). CONCLUSIONS Physiologically achievable doses of EGCG appear to enhance the efficacy of alkylating agents, purine nucleoside analogues, and alkylating agent/purine analogue combination therapy for the majority of CLL patients on in vitro testing. The favorable toxicity profile of EGCG and lack of myelosuppression with this agent in the phase I trial (JCO 27:3808-14) make it an attractive agent to test in combination with purine analogue and alkylator based chemo-immunotherapy for patients with CLL. Disclosures Kay: Genentech, Celgene, Hospira, Polyphenon Pharma, Sanofi-Aventis: Research Funding; Biogenc-Idec, Celgene, Genentech, genmab: Membership on an entity's Board of Directors or advisory committees. Shanafelt:Genentech: Research Funding; Hospira: Membership on an entity's Board of Directors or advisory committees, Research Funding; Polyphenon Pharma : Patents & Royalties, Research Funding; Celgene: Research Funding; Cephalon: Research Funding; Bayer Health Care Pharmaceuticals: Research Funding.

Abstract Abstract 2408 Purpose: Vitamin D insufficiency is common globally and in the United States. Approximately 25–50% of patients seen in routine clinical practice have vitamin D levels below the optimal range with low levels linked to higher cancer incidence. Although vitamin D insufficiency is also related to inferior prognosis in some cancers, no data exists for chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL). Patients and Methods: To test the hypothesis that vitamin D levels predict outcome in patients with CLL, we evaluated the relationship of 25 (OH)D serum levels with time-to-treatment (TTT) and overall survival (OS) in 390 newly diagnosed CLL patients participating in a prospective cohort study (discovery cohort) and separate cohort of 153 previously untreated patients participating in an observational study (confirmation cohort). 25 (OH)D levels were measured by liquid chromatography-tandem mass spectrometry. Intra- and inter-assay coefficients of variation were all <7% (data not shown). All vitamin D assays were performed on stored research samples; results were not included in the clinical record and were not known to the treating physicians in either study. Vitamin D insufficiency was defined as a serum 25 (OH)D level <25 ng/mL (62.5 nmol/L), an accepted level3 for the establishment of hypovitaminosis D and the threshold used in routine clinical practice to identify individuals with 25 (OH)D insufficiency by our laboratory in routine clinical practice (http://www.mayomedicallaboratories.com). Results: We evaluated the relationship of 25 (OH)D serum levels with time-to-treatment (TTT) and overall survival (OS) in newly diagnosed CLL patients participating in a prospective cohort study (discovery cohort) and a separate cohort of previously untreated patients participating in an observational study (confirmation cohort). Of 390 CLL patients in the discovery cohort, 119 (30.5%) were 25 (OH)D insufficient. 25 (OH)D insufficiency had no relationship with CD38, ZAP-70, CD49d or IGHV mutation status and had no relationship with FISH risk category as classified using the Dohner system. After median follow-up of 3 years, TTT (hazard ratio [HR]=1.66; p=0.005) and OS (HR=2.39; p=0.01) were shorter for 25 (OH)D insufficient patients (figure). We next attempted to validate these findings in an independent group of previously untreated CLL patients. In the validation cohort, 61 of 153 patients (39.9%) were 25 (OH)D insufficient. After median follow-up of 9.9 years, TTT (HR=1.59; p=0.05) and OS (HR 1.63; p=0.06) were again shorter for 25 (OH)D insufficient patients. On pooled multivariable analysis of patients in both cohorts adjusting for age, sex, stage, CD38, ZAP-70, IGHV, CD49d, and FISH, 25 (OH)D insufficiency remained an independent predictor of TTT (HR=1.47; p=0.008). On multivariable analysis for OS, the HR for death associated with 25 (OH)D insufficiency was similar to univariate findings although the p value did not reach the threshold of statistical significance (HR=1.47; 95% CI=0.97–2.23; p=0.07). Conclusion: 25 (OH)D insufficiency is associated with inferior TTT and OS in CLL patients. Whether normalizing vitamin D levels in deficient CLL patients would improve outcome merits clinical testing. Disclosures: Zent: Genzyme: Research Funding; Genentech: Research Funding; Novartis: Research Funding; G.S.K.: Research Funding.

Abstract Abstract 1241 Poster Board I-263 Background and Significance Monoclonal B lymphocytosis (MBL) is a hematologic syndrome characterized by accumulations of clonal B lymphocytes in the peripheral blood. Most MBL have a CLL-like immunophenotype, though other, less common phenotypes are observed. Although some MBL, particularly those with MBL cell counts >1.9 × 109 / L, progress to CLL, “low count” MBL (<0.2 × 109 MBL / μL) have little potential to progress to MBL and may have different biologic characteristics from MBL with lymphocytosis or Rai Stage 0 CLL. Our hypothesis was that detailed characterization of family-associated MBL may also provide biologic insights into the pathogenesis of CLL. Methods Individuals with MBL were identified by flow cytometry screening of fresh and cyropreserved peripheral blood from unaffected members of CLL kindreds ascertained by Genetic Epidemiology of CLL Consortium (GEC) sites. We defined MBL as populations of CD5+, CD19+, CD20lo, CD23+ B cells that comprised at least 0.02% of the PBMC and did not exceed 5.0 × 109 MBL cells / L. Flow cytometry was used to determine the surface immunophenotype including prognostic parameters of CD38, intracellular ZAP-70, immunoglobulin isotype, CD49d, and the ratio of CD69:71. mRNA and genomic DNA from single MBL cells isolated by flow cytometric sorting were analyzed using PCR to determine immunoglobulin heavy and light chain sequences (IGVH status). MBL cells were sorted in bulk for FISH determination of genetic loci associated with clinical CLL. Results Fifty-four unaffected family members were found to have MBL, of these 48 (89%) showed a typical CLL immunophenotype (CLL-like MBL). We observed significant variability in the size of the MBL clone as a percentage of the CD19+ B cell compartment (mean 30%, median 16%; range 2% - 97%). CD38 positive (defined as CD38 surface expression in ≥ 30% of MBL cells) was observed in 6 of 38 (16%) subjects tested. ZAP-70 positive (defined as intracellular expression in ≥ 20% of MBL cells) was expressed in 5 of 28 (18%) participants. CD49d positive (defined as surface expression in ≥ 45% of MBL cells) was observed in 4 of 17 (24%) subjects. The ratio of surface expression of CD69:CD71, a measure of cellular activation that also correlates with an unmutated IGVH, was ≥2.0 in 3 of 34 (9%) subjects tested. Among 36 subjects tested, 9 (25%) MBL expressed both surface IgD and IgM (defined as surface expression ≥ 40% for both IgM and IgD), 12 (33%) expressed IgD only, 2 (6%) expressed IgM only, and 13 did not express IgD or IgM (36%). Analysis of IGVH status has been completed in 10 individuals. Both immunoglobulin heavy chain variable (IGVH) region mutated (n = 14) and unmutated (n = 5) sequences were observed. Six of 10 individuals had 2 or more unrelated MBL clones (range 2 - 4), including two individuals with both unmutated and mutated clones. Among the 19 MBL clones identified in these 8 subjects, VH3 or VH4 rearrangements were observed in all MBL clones. The most commonly rearranged IGVH genes were 3-07 (3 MBL clones), 3-15 (3), and 4-34 (3). No VH1 family gene rearrangements were observed. MBL cells were bulk sorted for FISH from 14 subjects. Mono or biallelic deletion of 13q14.3 was observed in 9 subjects, 4 were normal, and one showed trisomy 12. Conclusions Our data affirms that CLL-like MBL are commonly observed among the unaffected family members from CLL kindreds. We found that family associated MBL clones (most of which were small clones) express ZAP-70, CD38, and CD49d at an apparently lower frequency than observed in CLL. Unlike in CLL, the surface immunoglobulin isotype showed co-expression of IgM and IgD in only one third of cases. Moreover, small MBL clones are commonly oligoclonal and predominantly express mutated IGVH genes with an IGVH usage that also appears different from CLL. Taken together, these findings suggest that small MBL clones, though phenotypically similar to CLL, have important biologic differences from CLL that may explain the limited potential of these clones to progress to CLL. The clinical outcome of these MBL clones in relation to our baseline prognostic characterization will be of interest. In addition the further investigation of family associated MBL is being conducted and may clarify the genetics and immunobiology of familial CLL. Disclosures No relevant conflicts of interest to declare.

Abstract Abstract 1245 Poster Board I-267 Introduction Chronic lymphocytic leukemia (CLL) patients with del(11q) by fluorescence in situ hybridization (FISH) have a poor prognosis. These patients often have younger age of onset, bulky lymphadenopathy, and short clinical response to treatment with purine analogues. Deletion of 11q in CLL is thought to involve loss-of-function of ataxia-telangiectasia mutated (ATM), a protein kinase central to DNA damage responses. As part of a larger study of early-intermediate stage, high risk CLL patients, we applied whole genome copy number variation (CNV) analysis to characterize the genomic alterations in CLL patients with and without del(11q) by FISH. Patients and Methods We studied 17 patients aged 29-67 with early-intermediate stage, untreated CLL who had high risk for disease progression based on evaluation of molecular and immunophenotypic markers. Of these patients, six had del(11q) by FISH analysis. No patients in this study had del(11q) as a sole FISH abnormality. CLL cells and normal cells were separated by magnetic bead selection from patient peripheral blood samples with absolute lymphocyte counts that ranged from 7.4 to 106 × 109/L. CNV analysis was performed on purified genomic DNA from the CLL cells and from normal cells for each patient in order to distinguish acquired CNVs in malignant cells from polymorphic CNVs in the human genome. We used the Illumina human660w-quad beadchip, a single nucleotide polymorphism (SNP)-based microarray for whole-genome genotyping and CNV analysis that contains more than 550,000 tag SNPs and approximately 100,000 additional markers that target regions of common CNV. CNV data was analyzed using CNV partition (Illumina Genome Studio software) and PennCNV. Results CNV analysis reveals hemizygous deletions of 11q in all 6 patients positive for del(11q) by FISH. The size of the deletion varies from ∼980 Kb to ∼44 Mb. All deletions include the region of the ATM gene at 11q22.3. No large homozygous deletions of 11q were detected. The three largest interstitial deletions (∼39 Mb, ∼41 Mb, ∼44 Mb) span 11q14.1-q23.3. A slightly smaller deletion of ∼33 Mb spans 11q14.2-q23.3. One deletion of ∼8.6 Mb covers 11q22.1-q22.3. The smallest deletion of ∼980 Kb is found within 11q22.3, centered on the ATM gene. Three out of 6 patients show complex interstitial deletions of 11q that consist of two or more discontinuous segments of loss of heterozygosity (LOH) separated by short undeleted regions. Five out of 6 patients with 11q deletions also show 13q hemizygous deletion by CNV analysis and by FISH. In 4 of these patients, the 11q and 13q interstitial deletions are the only acquired CNV events detected in the CLL genome. In one patient with 11q and 13q interstitial deletions, CNV analysis also shows chromosome 12 copy number (CN)=3 (also detected by FISH), CN=3 at 3q24-telomere (tel), and LOH events consistent with hemizygous deletion at 11p13 and 7p15.2-tel. Most noteworthy are 2 patients negative for any FISH abnormality who show copy-neutral LOH of most of 11q. The region of copy-neutral LOH includes 11q12-tel in one patient and 11q13.1-tel in the other patient. The copy-neutral LOH event involves close to 100% of the CLL cells in one patient, but only about 50% of the CLL cells in the other patient. Conclusions Whole genome CNV analysis by SNP-based microarrays greatly expands our ability to detect acquired genomic events in CLL cells and provides a powerful tool for CLL clinical research. Applying this new genomic technology to CLL patients with 11q deletions reveals marked complexity in the size and structure of hemizygous deletion events, which include the region of the ATM gene at 11q22.3 and can be discontinuous, indicative of complex genomic events. We identified copy-neutral LOH of 11q in 2 patients, a finding not previously described in CLL cells. Copy-neutral LOH of 11q is a genetic mechanism by which biallelic mutations of ATM, in cooperation with the loss of other tumor suppressor genes on 11q, may contribute to poor outcomes in some CLL patients without detectable FISH abnormalities. Additional studies, including sequencing of the ATM gene in 11q copy-neutral LOH patients, are required to confirm this hypothesis. Disclosures Shanafelt: Genentech, Hospira, Polyphenon E International, Celgene, Cephalon, Bayer Health Care Pharmaceuticals: Research Funding. Kay:Genentech, Celgene, Hospira, Polyphenon Pharma, Sanofi-Aventis: Research Funding; Biogenc-Idec, Celgene, Genetech, Genmab: Membership on an entity's Board of Directors or advisory committees. Zent:Genentech: Research Funding; Bayer: Research Funding; Genzyme: Research Funding; Novartis: Research Funding.

Abstract Background: PRCA is characterized by severe normochromic normocytic anemia, reticulocytopenia, and markedly reduced bone marrow erythroid precursors with intact leukocytic and megakaryocytic lineages. There is limited information about the prevalence and outcomes of PRCA in CLL, with the vast majority of information derived from case reports and small series comprising <10 patients. Here, we describe the clinical features, therapy, and outcomes of CLL patients with PRCA seen at our institution. Methods: The Mayo Clinic CLL Database includes all patients with a diagnosis of CLL evaluated at Mayo Clinic Rochester, MN between January 1995 and December 2014. We identified patients diagnosed with PRCA per the following diagnostic criteria: those who presented with normocytic anemia, had decreased erythroid precursors on bone marrow examination, and reticulocytopenia that could not be explained by any other cause besides PRCA. The baseline demographics, clinical characteristics, therapy, and outcomes were abstracted from the electronic medical records. We generated descriptive statistics and calculated overall survival (OS) from diagnosis date (PRCA, autoimmune cytopenia [AID], or CLL) to last known alive or death date. OS was plotted using Kaplan Meier curves and compared between groups using log-rank statistic. The Mayo Clinic IRB approved this study. Results: Of the 3945 CLL patients seen during the study interval, we identified 30 patients who met the diagnostic criteria of PRCA as described in the Methods section. The baseline characteristics, etiology and therapy for PRCA are shown in Table 1. The median time to PRCA from CLL diagnosis was 4.5 years (range-0.1-14 years). Of the 13 patients with IGHV results available, 12 (92%) were IGHV unmutated. Twenty-one (70%) were male and their median age at PRCA diagnosis was 67 years (range 40-81 years). Parvovirus testing was positive in 6 of 24 (25%) patients who were tested; 3 of these patients were treated with IVIG, 2 were treated with prednisone and IVIg, and 1 was treated with prednisone and rituximab. Eight patients (27%) had both PRCA and autoimmune hemolytic anemia (AIHA), and 1 patient (3%) had concomitant PRCA and immune thrombocytopenia (ITP). Of the 27 patients for whom we have treatment data, 10 required only one treatment regimen and 17 required 2-6 treatment regimens, with two patients requiring splenectomy for concomitant AIHA. The median survival of CLL patients after a diagnosis of PRCA was 4.6 years (Figure 1). There was no difference in survival between PRCA cases with and without parvovirus (p=0.92). Compared to newly diagnosed CLL Rai stage III/IV patients, there was no difference in OS (p=0.53). There was no statistically significant difference in survival from an AID cytopenia diagnosis when comparing PRCA, ITP, AIHA, and Evans syndrome (Figure 1; median 5 years for PRCA and 6 years for other groups; p=0.17). Conclusion: PRCA is a rare complication in CLL, occurring in <1% CLL patients seen at our institution over the past 20 years. Parvovirus was the etiologic factor in ~25% of patients and did not influence outcomes. There appears to be no significant difference in outcomes of PRCA patients compared to patients with other AID in CLL. Table 1. Patient Characteristics Characteristic N [range] or (%) Number of patients 30 Males 21 (70) IGHV status* · Unmutated · Mutated 12 (92) 1 (8) FISH results at CLL diagnosis* · 17p- · 11q- · Trisomy 12 · 13q- · Negative 0 (0) 1 (10) 3 (30) 3 (30) 3 (30) At PRCA Diagnosis Median age 67 [40 - 81] Median hemoglobin (gm/dL)* [normal range 12-15.5 gm/dL] 8.2 [3.5 - 10.8] Median absolute reticulocyte count (x 109/L)* [normal range: 38 - 113 x 109/L] 3.5 [0.0 - 25.3] Patients treated for CLL prior to PRCA diagnosis 25 (83) Etiology of PRCA Parvovirus (n = 24) 6 (25) Therapy-related: · Fludarabine · Alemtuzumab/rituximab · Pentostatin/cyclophosphamide/rituximab 3 (10) 1 (3) 1 (3) Autoimmune (neither therapy nor parvovirus related) 19 (63) Initial Therapy of Non-Parvovirus Related PRCA Steroids alone 2 (8) Steroids and Rituximab 3 (13) Steroids in combination with: · IVIG, Chlorambucil · Cyclosporine · Rituximab, IVIg · IVIg, splenectomy 1 (4) 2 (8) 1 (4) 1 (4) Monoclonal Ab alone · Alemtuzumab · Rituximab 1 (4) 4 (17) Cyclosporine 1 (4) Cyclophosphamide 2 (8) RCP (Rituxan, Cyclophosphamide, and prednisone) 2 (8) IVIg 1 (4) Not available 3 (13) *Not available for all patients Figure 1. Figure 1. Disclosures Ding: Merck: Research Funding. Kay:Gilead: Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics: Research Funding; Hospira: Research Funding; Tolero Pharma: Research Funding; Celgene Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding; Genentech: Research Funding. Shanafelt:Cephalon: Research Funding; Hospira: Research Funding; Glaxo-Smith-Kline: Research Funding; Genentech: Research Funding; Jannsen: Research Funding; Celgene: Research Funding; Polyphenon E International: Research Funding; Pharmacyclics: Research Funding.

Abstract Abstract 1246 Poster Board I-268 B-cell chronic lymphocytic leukemia (B-CLL) is characterized by a variable clinical course. Genomic aberrations as detected by FISH analysis and the mutational status of the IgVH genes have been found to have prognostic clinical significance with unmutated IgVH genes associated with clinically more aggressive disease. Previous studies have suggested that unmutated IgVH B-CLL is associated with increased chromosomal instability and increased chromosomal aberrations leading to accelerated disease progression. We recently performed a high-throughput, high-resolution array-based comparative genomic hybridization (aCGH) in a cohort of B-CLL patients. Fifty-eight patients have been analyzed by using the Sureprint G3 microarray (one million probes, Agilent). Our working hypothesis was that we would see increased genomic aberrations and instability in the unmutated IgVH group. The total number of copy number aberrations and total megabases (Mb) deleted or gained per genome were used as a surrogate marker for genomic instability. Variations in chromosomal aberrations in various VH families were also evaluated. B-CLL with unmutated IgVH genes utilized members of the VH1, VH3, VH4 and VH5 families with VH1-69 the most prevalent. B-CLL with mutated IgVH genes utilized VH families VH1, VH2, VH3, VH4, and VH6. Considerable variation was seen in the number of genomic abnormalities between cases. Overall, 315 abnormalities have been identified (236 deletions and 79 gains), with a median of 4 copy-number abnormalities per patient (range 0-32). In patients with IgVH mutational status available the median number of chromosomal aberrations in the mutated group was 5 (range 1-17) and unmutated group was 4 (range 0-20). Copy number deletions were significantly more common than chromosomal gains for the total group and in both the unmutated and mutated IgVH gene groups. Mean number of megabases (Mb) of DNA deleted in the unmutated IgVH group was 17.80Mb (standard deviation 24.17 Mb, median 6.63 Mb, range 0 - 90.55Mb) and 40.65 Mb in the mutated IgVH group (standard deviation 86.04 Mb, median 15.35Mb, range 0 – 307.57Mb). Mean number of Mb gained in the unmutated group was 37.74Mb (standard deviation 57.58Mb, median 0.44Mb, range 0 – 132.47Mb) and 32.99Mb (standard deviation 59.76Mb, median 0.14Mb, range 0 – 172.50Mb) in the mutated group. Nine patients had B-CLL with VH1-69 genes and 8 of them were unmutated. Median number of chromosomal deletions was 2 and gains also 2 (ranges 0 – 8 deletions and 0 – 4 gains) for this group. Similar findings were seen for the other VH families. These results initially suggest that total copy number variations do not account for the observed clinical differences between mutated and unmutated IgVH B-CLL. The catalogue of potentially clinically relevant chromosomal abnormalities found in this aCGH study is being currently evaluated. Disclosures Zent: Genentech, Bayer, Genzyme, Novartis: Research Funding. Shanafelt:Genentech: Research Funding; Hospira: Membership on an entity's Board of Directors or advisory committees, Research Funding; Polyphenon E International: Research Funding; Celgene: Research Funding; Cephalon: Research Funding; Bayer Health Care Pharmaceuticals: Research Funding. Kay:Genentech, Celgene, Hospira, Polyphenon Pharma, Sanofi-Aventis: Research Funding; Biogenc-Idec, Celgene, Genentech, genmab: Membership on an entity's Board of Directors or advisory committees. Fonseca:BMS: Consultancy; Amgen: Consultancy; Otsuka: Consultancy; Celgene: Consultancy; Medtronic: Consultancy; Genzyme: Consultancy.

Abstract Abstract 1232 Poster Board I-254 B-Chronic Lymphocytic Leukemia (CLL) shows a strong familial risk and also co-aggregates with other indolent lymphomas. Monoclonal B-cell lymphocytosis (MBL) is an asymptomatic hematologic condition characterized by small B-cell clones, most with a surface phenotype similar to that of chronic lymphocytic leukemia (CLL). These clones are detectable at low absolute lymphocyte cell (ALC) numbers in otherwise healthy individuals using sensitive 6 or 8 color flow cytometry analysis and can be a precursor to CLL. In the general population, MBL increases with age with a prevalence of 5% in individuals over age 65. In contrast, the rate of MBL is 13-18% in first degree relatives of CLL patients in high risk families. In the largest study to date, we report the characteristics of MBL among 430 first-degree relatives of CLL patients (with no associated lymphoproliferative diseases [LPD]) in 132 high risk families. Patients and Methods Individuals studied came from “high risk” families (defined as those with two or more confirmed cases of CLL) that are participating in the Genetic Epidemiology of CLL Consortium. Multi-parameter flow cytometry analysis with a detection sensitivity of 0.02% was performed on either fresh or cryopreserved PBMC and MBL was classified according to previously published criteria (Marti et al, Br. J Haematol 130:325, 2005). Both the ALC and the absolute B cell count (B-ALC) were calculated for each individual. Survival analysis was used to compute the probability of developing MBL with age using the life table method. Results The overall rate of MBL was 17% (73/430) among first–degree relatives but the probability for developing MBL by age 90 was 51%. Males had a slightly higher (but non-significant) risk for MBL than females. MBL patients had significantly higher ALC and B-ALC than did those with normal immunophenotype. The mean ALC was 2.5×109/L among MBL patients, and 20% had an ALC greater than 3 ×109/L. The B-ALC count averaged 0.51 ×109/L. Ninety percent of the MBL cases had a CLL-like phenotype (CD20dim, CD5+, CD23+). Conclusions MBL is found at a very high rate in families selected for having 2 or more patients with CLL suggesting that MBL reflects inherited predisposition to CLL. Although most of the MBL cases in these families had low cell counts and thus have a presumed low likelihood of progressing to CLL or other LPD, a higher proportion of them had lymphocytosis compared to those with normal immunophenotype. We hypothesize that if MBL is an early step in the process of development of CLL, then germ line genes are likely to be acting early in carcinogenesis with more “hits” required before CLL develops. By looking for genes associated with MBL or CLL in families or in the population, we could substantially increase our power to identify germ line genes predisposing to CLL. Disclosures Kay: Biogenc-Idec, Celgene, Genentech, genmab: Membership on an entity's Board of Directors or advisory committees; Genentech, Celgene, Hospira, Polyphenon Pharma, Sanofi-Aventis: Research Funding.