Citations

Abstract Introduction: Observation is the standard of care for asymptomatic early stage chronic lymphocytic leukemia (CLL) however these cases follow a heterogenous course. Recent studies show novel biomarkers can delineate indolent from aggressive early stage disease and current clinical trials are exploring the role of early intervention in high risk cases. Although several scoring systems have been established in CLL, most are designed for overall survival, do not circumscribe early stage disease, and require cumbersome calculations relying on extensive laboratory and clinical information. Aim: We propose a novel laboratory-based prognostic calculator to risk stratify time to first treatment (TTFT) in early stage CLL and guide candidate selection for early intervention. Methods: We included 1574 cases of early stage CLL in an international cohort from Italy, the United Kingdom and the United States using a training-validation model. Patient information was obtained from participating centers in accordance with the Declaration of Helsinki. The training cohort included 478 Rai 0 cases from a multicenter Italian cohort, all referred to a single center (Clinical and Experimental Onco-Hematology Unit of the Centro Riferimento Oncologico in Aviano, IT) for immunocytogenetic lab analyses. Considering TTFT as an endpoint, we evaluated 8 variables (age>65, WBC>32K, 17p-, 11q-, +12, IGHV status, CD49d+, gender) with univariate and multivariate Cox regression internally validated using bootstrapping procedures. FISH thresholds were 5% for 11q-, and +12 and 10% for 17p-. Cases were categorized according to the hierarchical model proposed by Dohner. IGHV status was considered unmutated at ≥98%. CD49d+ was set at >30%. WBC cutoff of >32K was established by maximally selected log rank analysis. Variables were weighted based on the proportion of their normalized hazard ratios rounded to the nearest whole integer. We used recursive partitioning for risk-category determination and Kaplan-Meier analysis to generate survival curves. We compared the concordance index (C-index) of our model with the CLL international prognostic index (CLL-IPI) for 381/478 cases in the training cohort with available beta-2-microglobulin data and for all validation cohorts. We used 3 independent single-center cohorts for external validation. Results: The training cohort had 478 cases of Rai 0 CLL with a median (95% CI) TTFT of 124 months (m) (104-183m). Five prognostic variables emerged with respect to TTFT, and each assigned a point value of 1 or 2 according to their respective normalized HR values as follows: 17p-, and UM IGHV (2 pts); 11q-, +12, and WBC>32K (1 pt). We identified three risk groups, based on point cut-offs of 0, 1-2, and 3-5 established by recursive partitioning analysis with a median (95% CI) TTFT of 216m (216-216m), 104m (93-140m) and 58m (44-68m) (p<0.0001, C-index 0.75) for the low, intermediate, and high-risk groups, respectively (figure 1). A comparison with the CLL-IPI was possible in 381 cases with available beta-2-microglobulin data. In this subset, the C-index was 0.75 compared to 0.68 when patient risk groups were split according to the CLL-IPI. The scoring system was then validated in 3 independent cohorts of early stage CLL: i) Gemelli Hospital in Rome, IT provided 144 Rai 0 cases. Median (95% CI) TTFT was 86m (80-94m, 95% CI). Median (95% CI) TTFT for the low, intermediate and high-risk groups was 239m (239-239m), 98m (92-132m) and 85m (60-109m) respectively (p=0.002 between low and intermediate groups, p=0.09 between intermediate and high groups; C-index 0.64 v 0.60 for CLL-IPI). ii) Cardiff University Hospital in Wales, UK provided 395 Binet A cases. Median (95% CI) TTFT was 74 m (67-81m) overall and NR, 111m (97-146m) and 70m (29-114m) for the low, intermediate and high-risk groups respectively (p<0.001 between low and intermediate groups, p=0.009 between intermediate and high groups; C-index 0.63 v 0.63 for CLL-IPI). iii) Mayo Clinic in Rochester, MN provided 557 Rai 0 cases. Median (95% CI) TTFT was 127m (96m-NR) overall and NR, 76m (64m-NR) and 36m (31-59m) for the low, intermediate and high-risk groups respectively (p<0.0001; C-index 0.72 v 0.68 for CLL-IPI). Conclusion: We present a novel laboratory-based scoring system for Rai 0/Binet A CLL to aid case selection in risk-adapted treatment for early disease. Further comparison to existing indices is needed to verify its utility in the clinical setting. Disclosures Zaja: Novartis: Honoraria, Research Funding; Takeda: Honoraria; Abbvie: Honoraria; Celgene: Honoraria, Research Funding; Amgen: Honoraria; Janssen: Honoraria; Sandoz: Honoraria. Fegan:Roche: Honoraria; Napp: Honoraria; Janssen: Honoraria; Gilead Sciences, Inc.: Honoraria; Abbvie: Honoraria. Pepper:Cardiff University: Patents & Royalties: Telomere measurement patents. Parikh:AstraZeneca: Honoraria, Research Funding; Janssen: Research Funding; MorphoSys: Research Funding; Abbvie: Honoraria, Research Funding; Gilead: Honoraria; Pharmacyclics: Honoraria, Research Funding. Kay:Janssen: Membership on an entity's Board of Directors or advisory committees; Acerta: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Infinity Pharm: Membership on an entity's Board of Directors or advisory committees; Cytomx Therapeutics: Membership on an entity's Board of Directors or advisory committees; Tolero Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding; Morpho-sys: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Agios Pharm: Membership on an entity's Board of Directors or advisory committees.

Abstract Immunomodulatory drugs (IMiDs) are widely used in the treatment of patients with Multiple Myeloma (MM) however, only 30% of relapsed MM patients respond to single agent therapy and most patients eventually develop drug resistance. The molecular target of IMiDs in MM is cereblon but other parallel pathways or downstream events which enhance or preclude drug responsiveness are unknown. We therefore conducted a genome scale small interfering RNA (siRNA) lethality study in MM in the presence of increasing concentrations of lenalidomide. Primary screening was performed in a single-siRNA-per-well format with the human druggable genome siRNA set V4 comprising four siRNAs targeting each of 6,992 genes (total 27968 siRNAs). Lenalidomide was added 24 hours post transfection and cell viability was measured by ATP-dependent luminescence at 144 hours after transfection. Primary screen data was rigorously evaluated for multiple quality control metrics and found to exceed all expected performance parameters with >98% global transfection efficiency, <0.25 CV values, and minimal plate-to-plate and set-to-set variations observed. Hit selection was performed by analysis of IC50 value shift in the presence of each testing siRNA compared with three different control siRNA oligos. 160 candidate genes that enhance lenalidomide sensitivity upon silencing (sensitizers) were selected and re-screened with four siRNA oligos targeting each gene. 50 genes were identified as reproducible lenalidomide sensitizers including three Peroxisome (PEX) family proteins (PEX1, PEX10 and PEX7) and seven RAB family proteins (RAB17, RAB1A, RAB26, RAB30, RAB36, RAB4A and RAB8A). Four kinase genes were also identified in sensitizer hits and two of these, I-Kappa-B Kinase-Alpha (IKK1 or CHUK) and ribosomal protein S6 kinase (RPS6KA3 or RSK2), encode proteins that associate with significance together with a phosphorylation dependent transcription factor (CREB1) in Toll signaling pathways (p-value 0.0068). RSK2 is a serine/threonine-protein kinase that acts downstream of oncogenic FGFR3 mediated signaling and is phosphorylated by ERK (MAPK1/ERK2 and MAPK3/ERK1 signaling) during hematopoietic transformation. Phosphorylated RSK2 was previously reported to be frequently expressed in myeloma cell lines and primary myeloma cells. Using lentiviral shRNA expression, we demonstrated that knockdown of RSK2 in three genetically variable MM cell lines induced cyctocytoxiticy and consistently sensitized to lenalidomide. Two selective small molecular inhibitors of RSK2 (SL 0101-1 and BI-D1870) were then demonstrated to synergize with lenalidomide to induce myeloma cell cytotoxicixity. To further understand the mechanism underlying sensitization, immunoblotting analysis was performed to look at downstream changes after either RSK2 knockdown or RSK2 inhibition by BI-D1870. We found that both RSK2 knockdown and BI-D1870 treatment, mimicking lenalidomide treatment or cereblon inhibition, induced downregulation of both IRF4 and MYC in MM cells. The combination of lenalidomide and BI-D1870 not only produced a substantial synergistic effect inducing MM cytotoxicity, but also demonstrated a significant enhancement of downregulation of IRF4 and MYC. Forced overexpression of RSK2 attenuated the synergistic effects of lenalidomide and BI-D1870. In summary, our high throughput screen identified multiple gene targets that associate with increasing sensitivity to IMiDs in MM cells, of which, RSK2 was further validated by both shRNA silencing and specific inhibitors as an effective target to cooperate with IMiDs to induce myeloma cytotoxicity. Clinical studies of RSK2 inhibition in concert with IMiD (cereblon inhibitor) therapy would be appropriate. Disclosures: Stewart: Onyx: Consultancy, Research Funding; Millennium: Honoraria, Research Funding; Celgene: Honoraria; BMS: Honoraria.

Abstract The characteristic clinical heterogeneity observed in chronic lymphocytic leukemia (CLL) reflects its biological diversity and as a consequence, better understanding of the biology of this disease has led to the identification of a number of useful prognostic tools. Advances in massively parallel sequencing technologies have unearthed genetic and epigenetic heterogeneity and reinforced the concept that specific genetic lesions and the development of genomic complexity can modulate the pathology of CLL. In addition, DNA methylation profiling has shown that CLL patients can be grouped into at least three clinically relevant epigenetic subgroups with distinct outcomes. However, despite this explosion in knowledge, defining the prognosis of individual CLL patients remains a significant clinical challenge. Consequently, there is a need to identify prognostic tests that can provide reliable personalized risk assessments. We have recently shown that a subset of CLL patients manifest telomere dysfunction, which drives genomic instability and clonal evolution. We went on to show an association between short, dysfunctional telomeres and 'high-risk' genetic lesions1,2. Importantly, longitudinal analysis confirmed that tumor cell telomere length remained remarkably stable throughout the course of the disease suggesting that the telomere length is fixed at an early point in disease pathogenesis making it a reliable predictor of both clinical progression and overall survival (OS) regardless of when the measurement is made. In this study, we generated telomere length profiles in 224 newly diagnosed, early stage CLL patients seen at the Mayo clinic in Rochester using high-throughput single telomere length analysis (HT-STELA). We then tested the ability of telomere length to predict time to treatment (TTT) and OS and compared its predictive power with DNA methylation profiling and CLL-IPI scores. Patients with a mean telomere length inside the fusogenic range (IFR) had a significantly shorter time to treatment (P<0.0001; HR = 3.2) and OS (P = 0.0027; HR = 2.3) when compared to patients with a mean telomere length outside the fusogenic range (OFR) (Figure 1A and B). When considering epigenetic subgroups, we found a strong association between telomere length and 'epitype'; high programmed (HP) CLL cells had significantly longer telomeres than intermediate programmed (IP), and low programmed (LP) CLL cells (P = 0.0002 and P<0.0001 respectively). Furthermore, bifurcation of the HP and IP groups into telomere length OFR and IFR subsets identified patients with distinctly different TTT (P = 0.0008; HR = 2.74) and OS (P = 0.004; HR = 2.4). 79/81 (97.5%) of the LP group had short telomere length IFR, but when we divided the LP group above and below the mean telomere length of the fusogenic range (≤/>2.17kb), patients with the shortest telomeres had a significantly worse OS (P = 0.034; HR = 2.83). Telomere length was also strongly associated with CLL-IPI score; the CLL-IPI low-risk group (CLL-IPI 1) had the longest telomeres and the CLL-IPI high-risk group (CLL-IPI 4) had the shortest telomeres (P<0.0001). More heterogeneity in telomere length was observed in the CLL-IPI 1 and 2 groups and patients with telomere length IFR in these 'low-risk' groups showed significantly shorter TTT (P<0.0001; HR = 4.24) and overall survival (P<0.0001; HR = 10.1) (Figure 1C and 1D). Finally, multivariate modelling, using Cox proportional hazards with forward selection, revealed that telomere length retained independent prognostic significance when CLL-IPI score was entered in the model for time to treatment (HR = 1.42; P = 0.023) and OS (HR = 1.68; P = 0.008). In conclusion, telomere length analysis provides more accurate prognostic information about the progression and outcome of CLL patients and can augment the prognostic power of the CLL-IPI for early stage CLL. References Lin TT et al. Blood. 2010;116(11):1899-907. Britt-Compton et al. Leukemia. 2012; 26(4):826-30. Disclosures Norris: Cardiff University: Patents & Royalties: Telomere measurement patent. Shanafelt:GlaxoSmithKline: Research Funding; Genentech: Research Funding; Pharmacyclics: Research Funding; Jansen: Research Funding. Kay:Acerta: Research Funding; Tolero Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding; Cytomx Therapeutics: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Agios Pharm: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Infinity Pharm: Membership on an entity's Board of Directors or advisory committees; Morpho-sys: Membership on an entity's Board of Directors or advisory committees. Fegan:Napp: Honoraria; Gilead Sciences, Inc.: Honoraria; Roche: Honoraria; Abbvie: Honoraria; Janssen: Honoraria. Baird:Cardiff University: Patents & Royalties: Telomere measurement patents. Pepper:Cardiff University: Patents & Royalties: Telomere measurement patents.

Abstract Introduction: Carfilzomib (CFZ) is a structurally- and mechanistically-novel proteasome inhibitor (PI) of the peptide epoxyketone class that exhibits a high level of selectivity for the unique N-terminal threonine active sites within the proteasome. CFZ is similar to bortezomib (BTZ; VELCADE®), in that it is a potent inhibitor of the chymotrypsin-like activity, but unlike BTZ, CFZ has shown minimal cross-reactivity with the other catalytic sites within the proteasome or across other protease classes. Preclinical human tumor xenograft models indicate that consecutive day (D1, D2) dosing resulting in 48 hours of proteasome suppression was superior to split dosing (D1, D4). Methods: This phase 1 sequential dose escalation trial tested an intensive proteasome inhibition schedule with CFZ administered as an intravenous push (IVP) daily (QD) for 5 consecutive days on a 14 day cycle. The doses administered ranged from 1.2 mg/m2 to 20 mg/m2. Multiple myeloma (MM), non-Hodgkin’s lymphoma (NHL) that included mantle cell lymphoma (MCL), Hodgkin’s disease (HD), or Waldenström’s macroglobulinemia (WM) were eligible if they had relapsed after 2 or more prior therapies. Results: A total of 29 subjects have been treated. The minimal effective dose (MED) was 11 mg/m2. A maximum of 80% proteasome inhibition was achieved in peripheral blood and mononuclear cells at ≥15 mg/m2. Five responses have occurred in 14 patients (6 MM, 3 MCL, 1 WM, 4 NHL) enrolled at ≥ the MED: 1 MM partial response (PR), 2 MM minimal responses (MR), 1 WM MR and one macroscopic CR in a patient with gastrointestinal MCL. Responses occurred in patients whose disease had failed therapy with BTZ, immunomodulatory agents, and stem cell transplant. Four NHL patients have had stable disease and remained on treatment for up to 7 months. Dose limiting toxicity reported at 20 mg/m2 included febrile neutropenia (reversible) and grade 4 thrombocytopenia. Grade 3 (25%) or grade 4 events (8%) were primarily hematologic events. Most withdrawals occurred due to the inconvenience of frequent visits, or progressive disease. Conclusions: This study demonstrates that intensive CFZ dosing leading to sustained proteasome inhibition is well tolerated. The selectivity of the epoxyketone class of PI may promote a favorable safety profile. Furthermore, antitumor responses in heavily pretreated patients suggest non-cross resistant activity. Phase 2 trials in MM and solid tumors are proceeding with an alternate IV schedule. An oral agent suitable for frequent dosing schedules is under development.

Abstract Abstract 3150 Introduction. Affordability of health care in the United States (US), and the impact of patient insurance coverage on it have been shown to be associated with the delivery and timeliness of access to care. With increasing costs of novel therapies in hematology and oncology, this concern has been raised in hematologic cancers. This analysis evaluates whether the health-related quality of life (HRQOL) of patients with active, symptomatic multiple myeloma (MM) patients in the US varies by their insurance coverage as they initiate treatment. Methods. Baseline data were collected in Connect MM®, a prospective observational registry initiated in September 2009 involving centers in the US. Data on patient demographics and clinical characteristics were provided by clinicians. HRQOL was reported by patients in the clinic at enrollment, within two months of diagnosis. Patients completed 3 psychometrically validated instruments: the Brief Pain Inventory (BPI), EQ-5D, and Functional Assessment of Cancer Therapy-Multiple Myeloma (FACT-MM). Standard analyses were conducted of each instrument given clinical characteristics at that time. Patients were characterized as to the main source of their insurance coverage: Medicare, Medicaid or Commercial. The Medicare cohort included those with supplemental commercial coverage, and the Medicaid cohort included those with dual Medicare-Medicaid coverage. Reported mean BPI, EQ-5D and FACT-MM scores were analyzed by patient insurance coverage. Statistical significance of score differences among sub-cohorts was ascertained by ANOVA using SAS 9.1. Results. HRQOL data and insurance status were reported by 863 patients, enrolled from 189 centers. Patients were predominantly male (57%) and white (82%) with mean age at 67.0 (standard deviation [SD] 11.3) yrs. HRQOL scores by insurance status are presented: Overall FACT-MM results indicate that Medicaid insurance status is associated with greater decrement in baseline HRQOL compared to the other groups. Statistically significant differences are noted in the FACT-G general cancer HRQOL score, and its physical, social/family and emotional component scores. BPI data (on a scale of 0 [no pain] to 10 [worst pain] indicate that average pain may be worse among Medicaid patients compared to either Medicare or commercially insured patients. There are no statistically significant differences on EQ-5D scores (on a scale of 1 [no problem] to 2 [some problems] to 3 [incapacity] between cohorts based on insurance status. Conclusions. Initial results from the Connect MM® Registry indicate that HRQOL at baseline prior to initiation of treatment is worse among Medicaid patients compared to those with either Medicare or commercial coverage. This should be investigated to determine whether Medicaid patients are accessing care later in disease progression than others covered by Medicare or commercial insurance. Furthermore, future analyses should be conducted of patients by insurance coverage to determine whether status may be associated with access to medical care, subsequent clinical outcomes, and HRQOL over time. Results reported here should serve as a baseline reference. Disclosures: Pashos: Celgene: Membership on an entity's Board of Directors or advisory committees. Durie:Celgene: Membership on an entity's Board of Directors or advisory committees. Rifkin:Celgene: Membership on an entity's Board of Directors or advisory committees. Terebelo:Celgene: Membership on an entity's Board of Directors or advisory committees. Gasparetto:Celgene: Membership on an entity's Board of Directors or advisory committees. Mehta:Celgene: Membership on an entity's Board of Directors or advisory committees. Toomey:Celgene: Membership on an entity's Board of Directors or advisory committees. Abonour:Celgene: Membership on an entity's Board of Directors or advisory committees. Fonseca:Celgene: Membership on an entity's Board of Directors or advisory committees. Narang:Celgene: Membership on an entity's Board of Directors or advisory committees. Shah:Celgene: Membership on an entity's Board of Directors or advisory committees. Swern:Celgene Corporation: Employment, Equity Ownership. Sullivan:Celgene: Employment, Equity Ownership. Street:Celgene: Employment, Equity Ownership. Khan:Celgene: Employment, Equity Ownership.

Abstract Abstract 5070 Introduction. Studies in the United States (US) have identified variation in incidence and survival of multiple myeloma (MM) patients of different races, and noted that MM is the most common hematologic cancer among African Americans. This analysis was conducted to evaluate whether the health-related quality of life (HRQOL) of patients in the US as they initiate treatment with active, symptomatic MM varies by race. Methods. Data were collected in Connect MM®, a prospective observational registry begun in September 2009 involving centers in the US. Data on patient demographics and clinical characteristics were provided by clinicians. HRQOL was reported by patients in the clinic at enrollment, within two months of diagnosis. Patients completed 3 psychometrically validated instruments: the Brief Pain Inventory (BPI), EQ-5D, and Functional Assessment of Cancer Therapy-Multiple Myeloma (FACT-MM). Standard analyses were conducted of each instrument. Reported mean BPI, EQ-5D and FACT-MM scores were analyzed by patient race. Statistical significance of score differences was ascertained by ANOVA using SAS 9.1 in two ways: (1) among three different racial categories (White, Black and Other), and (2) between Blacks and non-Blacks. Hispanic/Latino patients and Asian patients comprise most of the Other cohort. Results. HRQOL data at baseline were reported by 916 pts, enrolled from 189 centers. Of these patients, 82% were White, 12% were Black, and 5% were of another race (Other). Among evaluable patients, the different race groups did not differ statistically by ECOG status or multiple myeloma stage (measured by either the International Staging System or the Durie and Salmon system). The three racial groups differed by age, with the mean (SD) age of Blacks (63 (11)) and Others (63 (13)) being less than that of Whites (68 (11), p<0.0001). Gender was trending, but not statistically significantly different, between races, with males comprising 58% of Whites, 52% of Blacks, and 46% of Others (p=0.1803). HRQOL scores by race are presented here: Overall FACT-MM results indicate that baseline HRQOL does not vary between races, as the main summary scores do not differ statistically, although the FACT-MM Total scores of Blacks and Whites are trending higher than those of Others. Only the emotional and social/family domain scores of the FACT-MM vary statistically, as Blacks show a worse mean score in the social/family domain and a better score in the emotional domain. BPI data (on a scale of 0 [no pain] to 10 [worst pain] do not show a statistically significant difference between races, and the same is true of the five EQ-5D domains (measured on a scale of 1 [no problem] to 2 [some problems] to 3 [incapacity]. Conclusions. Initial results from the Connect MM® Registry indicate that HRQOL at baseline prior to initiation of treatment does not vary by patient race. As such, these results may serve as a baseline reference for future analyses. In particular, as patients proceed through therapy, analyses should be conducted of patients by race, among other factors, to determine whether it may be associated with subsequent clinical outcomes and HRQOL over time. Disclosures: Pashos: Celgene: Membership on an entity's Board of Directors or advisory committees. Durie:Celgene: Membership on an entity's Board of Directors or advisory committees. Rifkin:Celgene: Membership on an entity's Board of Directors or advisory committees. Terebelo:Celgene: Membership on an entity's Board of Directors or advisory committees. Gasparetto:Celgene: Membership on an entity's Board of Directors or advisory committees. Mehta:Celgene: Membership on an entity's Board of Directors or advisory committees. Toomey:Celgene: Membership on an entity's Board of Directors or advisory committees. Abonour:Celgene: Membership on an entity's Board of Directors or advisory committees. Fonseca:Celgene: Membership on an entity's Board of Directors or advisory committees. Narang:Celgene: Membership on an entity's Board of Directors or advisory committees. Shah:Celgene: Membership on an entity's Board of Directors or advisory committees. Swern:Celgene Corporation: Employment, Equity Ownership. Sullivan:Celgene: Employment, Equity Ownership. Street:Celgene: Employment, Equity Ownership. Khan:Celgene: Employment, Equity Ownership.

Abstract Abstract 2864 Introduction: Clinical trials have illuminated a number of unique treatment strategies for patients with CLL. The impact of these strategies on routine practice remains unknown as trial participants may not reflect the same population encountered outside of a clinical trial setting. Many questions remain regarding the sequencing of therapies based on age and performance status. By characterizing current patterns of care; patients, treating physicians, and regulatory agencies will be able to understand the current landscape of CLL treatment. The Connect® CLL registry was designed to report the natural history and real world management of patients receiving therapy for CLL. In this first report, we characterize the therapeutic approaches used for the treatment of patients with CLL of different age groups (i.e. < 65 years, 65–75 years, and ≥ 75 years) and with an ECOG PS status score of 0 compared to 1 or greater. Methods: Connect® CLL is a prospective, longitudinal, observational, multi-center registry conducted in community and academic research centers in the United States. At present, 237 sites are actively participating with a projected study enrollment of 1500 patients. Eligible patients are to be enrolled within 2 months of being initiated on any line of therapy; whether initial therapy or salvage therapy. Each patient will be followed for up to 60 months. Clinical data, physician choices, patient-reported health-related quality of life, response and survival are to be collected approximately every 3 months during participation. Results: A total of 607 patients have been enrolled (4% from academic sites) with a median age of 70 years. 198 were < 65 years old (age group 1), 187 were between 65–75 years old (age group 2), and 222 were ≥ 75 years old (age group 3). ECOG status varied across the three age groups, with an ECOG status score of ≥ 1 for 39%, 52%, and 70% of patients respectively. Treatment patterns varied across the age groups and by ECOG status in the 496 patients reporting therapies. The most commonly recorded first-line regimens independent of age included fludarabine (F) cyclophosphamide (C) and rituximab (R) (33%), bendamustine (B) +/− R (19%), F +/− R (15%), or investigational therapy (15%). For second-line regimens and beyond, the most frequently recorded regimen was B +/− R (30%), FCR (23%), other F-based regimens (13%), or investigational therapy (8%). The use of FCR for first-line treatment decreased significantly with increasing age group, (45%, 32%, 20%, for age group 1, 2, 3 respectively, p=0.04, spearman correlation) while use of F +/− R remained level across the age groups (14%, 15%, 15%, respectively). Compared to age group 1, first-line therapy with B +/− R in age groups 2 and 3 (15%, 22%, 21%, respectively) was higher but did not achieve statistical significance. B +/− R represented the most common treatment for all age groups (37%, 26%, 29%, respectively) as second line therapy but did not vary by age (P=0.35). The use of chlorambucil was infrequent in all age groups, but was more common in age group 3 patients compared to the others (P=0.01), in both first-line (2%, 4%, 12%, respectively) and subsequent lines of therapy (0%, 1%, 8%, respectively). Treatment assignments did not vary by ECOG PS score for patients in age group 1. First-line therapy for patients with an ECOG PS score of 0 in age groups 2 and 3 consisted of FCR (32% and 15%, respectively), F +/− R (19% and 15%, respectively), B +/− R (16% and 15%, respectively), and alkylating agents (3% and 23%, respectively). Patients in age groups 2 and 3 with ECOG PS score ≥ 1 received B +/− R regimen (33% and 22%, respectively), FCR (23% and 21%, respectively), F +/− R (14% and 10%, respectively) and alkylating agents (7% and 9%, respectively) as first-line therapy. Further description and clarification on the various treatment regimens based on the three age groups and by ECOG PS score will be presented at the meeting. Conclusion: The Connect® CLL Registry is the largest prospective, multicenter registry in the United States evaluating management for patients with CLL. With the currently available data, we characterize the extent to which age and performance status are associated with treatment selection in both first-line and subsequent lines of therapy in routine practice. As enrollment increases and additional follow-up is completed, the data will provide more extensive and real world overview of the current treatment strategies used in CLL patients. Disclosures: Sharman: Celgene - consulting: Consultancy; Pharmacyclics: Honoraria; Calistoga: Honoraria; Portola pharmaceuticals: Consultancy. Flowers:Consultancy: Celgene, Prescription Solutions, Spectrum (future), Seattle Genetics, Millennium (future), Genentech (unpaid): Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Weiss:Celgene: Consultancy. Grinblatt:Celgene: Honoraria, Speakers Bureau. Kay:Genenetech, Celgene, Hospira,: Research Funding. Kipps:Igenica: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Research Funding; Abbot Industries: Research Funding; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees; Genentech: Research Funding; GSK: Research Funding; Gilead Sciences: Research Funding; Amgen: Research Funding. Lamanna:Celgene Corporation: Advisory board. Pashos:United BioSource Corporation: Research Funding. Flinn:Celgene: Research Funding. Kozloff:Celgene: Consultancy. Lerner:Celgene Connect: Membership on an entity's Board of Directors or advisory committees. Swern:Celgene: Employment. Sullivan:Celgene: Employment. Street:Celgene: Employment. Keating:Celgene Connect: Membership on an entity's Board of Directors or advisory committees.

Abstract Acquired hemoglobin H (HbH) disease (α thalassemia) can arise in the setting of marrow neoplasia, especially the myelodysplastic syndrome (MDS). This association has been termed α thalassemia-MDS (ATMDS, MIM #300448). Recently, we have linked ATMDS to acquired point mutations in the ATRX gene, which encodes an X-linked chromatin-associated factor whose precise normal cellular function is unknown (Steensma et al, Blood2004;103:2019, and Gibbons et al, Nature Genetics2003;34:446). We now describe a novel acquired splicing mutation in the helicase domain of the ATRX gene in a 71 year-old man of southern Italian descent. The patient, who previously had normal blood indices, presented with a 6-month history of microcytic anemia (Hb 7.7 g/dL, MCV 73.7 fL, reticulocytes 0.2%; WBC 11,800/uL with 29% circulating blasts). Peripheral smear demonstrated marked anisopoikilocytosis and the presence of poorly hemoglobinized ghost cells, while a marrow aspirate and biopsy revealed dysplastic features including atypical megakaryocytes, and approximately 20% blasts, consistent with a diagnosis of MDS in leukemic transformation. On supravital staining, approximately 30% of circulating erythrocytes contained HbH inclusions. The α/β globin transcript ratio measured by quantitative real-time PCR ranged between 0.11 and 0.39, compared with the mean ratio for 11 normals (α/β ratios in normals ranged between 0.8–1.2 fold of the mean). Despite this evidence of α thalassemia, no gross rearrangements of the α globin cluster were detected on Southern blotting or by FISH, and sequencing of the α globin genes was unremarkable. Screening of the entire coding region of the ATRX gene by denaturing high-performance liquid chromatograpy showed no abnormalities. Amplification and sequencing of cDNA made from the patient’s blood, however, revealed loss of ATRX exon 28 (in the middle of the putative helicase domain), resulting in a frame shift and generation of a premature stop codon. The causative mutation at the genomic level remains unknown, despite sequencing of the consensus splice sites framing both ATRX exon 28 and the surrounding regions. A clonally restricted mutation in a distant cryptic splice enhancer or inhibitor is suspected. Following treatment with idarubicin and Ara-C, the patient achieved a complete remission with normalization of red cell morphology and indices, and HbH was no longer detectable. This case emphasizes the need to search carefully for abnormal mRNA splicing when screening for ATRX mutations and provides further support for a link between ATRX mutations and ATMDS. Among 20 ATMDS patients analyzed molecularly, we have now characterized ATRX missense, null, and nonsense mutations in 9 patients, found a codon substitution of uncertain significance in 1 patient, and detected ATRX splicing mutations in 3 patients, including the present case. Additionally, one patient had an acquired α globin deletion limited to the neoplastic clone (Steensma et al, Blood2004; 103:1518). The molecular defect remains unknown in 6 cases. Since RNA is not available from these 6 archival cases, it is possible that they have ATRX splicing mutations as well.

Abstract Abstract 602 The molecular target(s) which co-operate with proteasome inhibition in inducing drug sensitivity or resistance in Multiple Myeloma (MM) remain unknown. We therefore conducted a genome scale small interfering RNA (siRNA) lethality study in KMS11 MM cells in the presence or absence of bortezomib without regard to pre-conceived mechanistic notions. Primary screening was performed in a single-siRNA-per-well format with the human druggable genome siRNA set V4 comprising 13,984 siRNA targeting 6,992 genes and comprising two RNAi per gene. siRNA were transfected at low concentration (13nM) to minimize off-target effects using conditions that resulted in transfection of >95% cells and <5% background cytotoxicity. Bortezomib was added (at the IC10, 25, 70 and 90) 24 hours post transfection. After 96 hours (72 hours after bortezomib), viability was measured by ATP-dependent luminescence. In primary screening 320 candidate bortezomib sensitizing genes were identified and rescreened with four siRNA oligos each gene. 57 of the top sensitizer hits were selected for which at least two distinct siRNA decreased the EC50 by 2 standard deviations from cells treated with control siRNAs. By cross referencing gene expression profile (GEP) data of KMS11, we furthered pared the list to 37 plausibly expressed targets (0.5% of those genes originally screened) as bortezomib sensitizers. After silencing, 50% of these 37 genes also sensitized the lung cancer cell line A549 to bortezomib. After further parsing of genes which also modulated the sensitivity of MM to Melphalan (non specific chemosensitizers), 34 genes remained: The strongest sensitizers to bortezomib were the proteasome subunits PSMA5, PSMB2, PSMB3, PSMB7 but included less obvious targets such as BAZ1B, CDK5, CDC42SE2, MDM4, NME7, TFE3, TNFAIP3, TNK1, TOP1, VAMP2 and YY1 were also identified. Of these, the most potent synergetic effects were observed with siRNAs against the proteasome subunits and against cyclin dependent kinase 5 (CDK5), which caused the greatest shift in EC50. CDK5 is of particular interest as a therapeutic target as it is expressed at high levels in MM and neural tissues but has low expression in other organs. Using viral shRNA expression, silencing CDK5 consistently increased the sensitivity of genetically variable MM cell lines (n=5) to all of the proteasome inhibitors tested: bortezomib, carfilzomib and PR047, and the effect could be at least partially rescued by overexpression of an RNAi resistant CDK5. To explore therapeutic relevance the small molecule CDK5 inhibitor, Roscovitin, was shown to be synergistic or additive with bortezomib in both MM cell lines and primary patient samples. Gene expression profiling was then performed to seek an explanation for the CDK5 sensitization effect and regulation of a proteasome subunit PSMB5 by CDK5 was identified as a probable route to sensitization. In summary inhibition of the existing proteasome either directly by suppression of proteasome subunits, or indirectly by suppression of modulators such as CDK5 appears to confer the greatest sensitization effect suggesting that combinations of bortezomib with other unique proteasome inhibitor drugs or combinations with inhibitors of CDK5 is a logical avenue for clinical exploration. Disclosures: No relevant conflicts of interest to declare.

Abstract Abstract 4048 Poster Board III-983 Introduction Iron deficiency is the most common nutritional disorder in the world with an estimated two billion affected persons. Although commonly considered environmental in origin, the existence of multiple genetic disorders of iron metabolism in man, rodents and other vertebrates suggest a genetic contribution to iron deficiency. Methods: The Hemochromatosis and Iron Overload Screening (HEIRS) Study is a multi-center, multi-ethnic study in which transferrin saturation (TS), serum ferritin (SF), and HFE mutations were determined in 101,168 adults. To identify genomic locations associated with iron deficiency, we performed a genome-wide association study (GWAS) using DNA collected from white HEIRS Study participants who had SF ≤ 12 μg/L (cases) and an equal number of white controls (SF > 100 μg/L in men, SF > 50 μg/L in women) frequency-matched to cases by sex and geographic location. Men aged ≥ 25 y and women ≥ 50 y were included in both groups. Tissue body iron, an index of iron deficiency, was estimated from serum transferrin receptor (sTfR) and SF. Genotyping was performed with the Illumina HumanCNV370K Beadchip platform. Quality control filters excluded single nucleotide polymorphisms (SNPs) or samples with > 5% missing genotypes, SNPs showing heterozygosity or Hardy-Weinberg deviations (P<10−7), and SNPs with minor allele frequency < 0.02. Population admixture/structure was assessed using principal component analysis. Regression analysis was used to examine the association between outcomes (case-control status, tissue body iron, serum ferritin, transferrin receptor, serum iron, total iron-binding capacity [TIBC], and unsaturated iron-binding capacity [UIBC]) and each SNP genotype variable; covariates included age, sex, and geographic location. Replication for 56 SNPs was conducted in a population attending primary care clinics at a Veterans Affairs (VA) medical center using the iPlex platform. Eligibility within the VA replication population was restricted to age and self-reported white ethnicity as for the HEIRS subset from a total of 2559 people (138 women). VA participants with SF ≤ 20 μg/L were classified as iron-deficient cases and frequency matched 1:2 with controls (men with SF > 100 μg/L and women with SF > 50 μg/L). Results The GWAS genomic control parameter was not significantly different from 1.0. There were 392 cases (96 men) and 390 controls (96 men) in the HEIRS subset GWAS with average age (SD) of 59 (10) y and 61 (11) y, respectively. Geometric mean SF (minimum, maximum), and mean (SD) for sTfR and tissue body iron in the HEIRS subset were 7.5 (1.2, 12) μg/L, 6.4 (3.77) mg/kg and -2.0 (2.50) for cases and 141 (51, 881) μg/L, 3.0 (0.98) mg/kg and 10.8 (2.5) for controls. After quality control tests, GWAS analysis included genotype data for 331,060 SNPs in 734 individuals (364 cases, 370 controls). For the VA replication population there were 67 male and 11 female cases, and 136 male and 27 female controls for whom DNA was successfully prepared; the average age (SD) was 68 (12) y for cases and 65 (11) y for controls. Regression analysis identified seven SNPs within four independent regions that replicated associations found in the GWAS (GWAS P<1×10-4 and VA P<0.05).The SNP rs6735681 on chromosome 2p24 was associated with serum iron (GWAS P<3.9×10-5, VA P=0.038). Three SNPs on chromosome 2p14 (rs6750096, rs2698541 and rs2698530) significantly influenced both TIBC and UIBC (GWAS P<2.9×10-5, VA P< 0.04 for all). Two SNPs in the TF gene region on chromosome 3q22 also showed significant effects on TIBC and UIBC (GWAS P<4.7×10-6, VA P<0.03 for all). The SNP rs10512064 on chromosome 9q21 was associated with serum ferritin concentration and tissue body iron (GWAS P<2.5×10-5, VA P<0.05 for both). Conclusion: From these GWAS and replication studies, we have identified three new genetic loci and one known iron gene, TF, associated with iron phenotype variability. These results point to specific loci as targets for gene identification and TF polymorphisms as determinants of iron metabolism, which in turn may play a role in regulation of body iron status. Disclosures: No relevant conflicts of interest to declare.