Habermann, Thomas M.

Abstract Abstract 3642 Purpose: The reactive pathologic background in nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) consists of lymphocytes and histocytes. Lymphopenia is a negative prognostic factor in NLPHL as it is also in Classical Hodgkin Lymphoma (cHL). In cHL, tumor-associated macrophages recruited from circulating monocytes are a negative prognostic factor for survival. Thus, we studied if the peripheral blood absolute lymphocyte count/absolute monocyte count ratio at diagnosis (ALC/AMC-DX), as a surrogate biomarker of the host response against the neoplastic lymphocytic and/or histiocytic (L&H) cells, affects survival in NLPHL. Patients and Methods: We performed a retrospective analysis of the association between ALC/AMC-DX and survival in 103 consecutive NLPHL patients that were followed at Mayo Clinic from 1974 to 2010. Receiver operating characteristic (ROC) and area under the curve (AUC) were used for ALC/AMC-DX cut-off value analysis and proportional-hazards models were used to compare survival based on the ALC/AMC-DX ratio. Results: The cohort included 67 (65%) males and 36 (35%) females. Eighty-three percent of patients presented with stage I/II and 17% with stage III/IV. Sixty-five (63%) patients were treated with radiation alone; 20 (20%) patients with chemotherapy alone; and 18 (17%) patients with chemotherapy and radiation. The median follow-up period was 8.9 years (range: 0.3–31 years). An ALC/AMC-DX ≥ 2.1 was the best cut-off value for survival with an empirical AUC of 0.82 (95% confidence interval [CI], 0.78 to 0.88), a sensitivity of 70% (95% CI, 61% to 76%) and specificity of 84% (95%CI, 59% to 82%). The cut-off value for ALC/AMC-DX ≥ 2.1 was validated by the k-fold cross validation method, showing a cross validation ROC with an AUC of 0.82 (95% CI, 0.72 to 0.93) for an ALC/AMC-DX ≥ 2.1. Using Kaplan-Meier analysis, we studied overall survival (OS), lymphoma-specific survival (LSS), progression-free survival (PFS), and time to progression (TTP) based on ALC/AMC-DX ≥ 2.1. Patients with an ALC/AMC-DX ≥ 2.1 experienced an superior OS, LSS, PFS, and TTP compared with patients with an ALC/AMC-DX < 2.1: [OS: median was 22.1 years vs 6.3 years, 10-years OS rates of 89% (95%CI, 80% to 98%) vs 44% (95%CI, 27% to 65%), p < 0.0001, respectively; LSS: median was not reached vs 7.3 years, 10-years LSS rates of 99% (95%CI, 90% to 100%) vs 45% (95%CI, 29% to 67%), p < 0.0001, respectively; PFS: median was 20.6 years vs 4.6 years, 10-years PFS rates of 84% (95%CI, 80% to 97%) vs 26% (95%CI, 18% to 55%), p < 0.0001, respectively; and TTP: median was not reached vs 5.5 years, 10-years TTP rates of 93% (95%CI, 85% to 99%) vs 29% (95%CI, 19% to 57%), p < 0.0001, respectively]. After adjusting for the International Prognostic Factors and the International Prognostic Score, ALC/AMC-DX remained an independent prognostic factor for OS {hazard ratio (HR), 0.42, 95%CI, 0.23 to 0.64, p< 0.004]; LSS [HR, 0.14; 95%CI, 0.04 to 0.23, p <0.0004]; PFS [HR, 0.14; 95%CI, 0.03 to 0.34, p < 0.001], and TTP [HR, 0.16, 95%CI, 0.04–0.34, p <0.002]. Conclusion: ALC/AMC-DX is an independent prognostic factor for survival and provides a single biomarker to predict clinical outcomes in NLPHL. Disclosures: No relevant conflicts of interest to declare.

Abstract Background IL-10 polarized macrophages promote tumor growth and survival. The T-cell transcription factor GATA binding protein-3 (GATA3) epigenetically regulates IL10 expression. Therefore, we investigated the extent to which GATA-3 regulates IL-10 production and macrophage polarization in T-cell lymphomas. Methods Monocyte-derived macrophages were generated and polarized with T-cell lymphoma conditioned media ((TCL-CM). Immunophenotypic and functional characteristics associated with IL10-polarized macrophages were examined. GATA3-dependent cytokine production was evaluated in T-cell lymphoma lines by shRNA knockdown. Alternatively polarized macrophages and GATA3 expression were examined in a cohort of patients with peripheral T cell lymphoma, not otherwise specified (PTCL, NOS) (n=76). Comparisons among groups were evaluated using a Student's t test. Progression-free and overall survival (PFS & OS) was estimated using the Kaplan-Meier method and two-tailed log-rank test based on Cox proportional hazards model. Results To investigate the ability of T-cell lymphomas to alternatively polarize macrophages, monocytes from healthy donors were cocultured with TCL-CM. Macrophages were shown to have immunophenotypic characteristics of IL10-polarized macrophages (pSTAT3+/CD16hi/CD163hi/HLA-DR-/lo) by flow cytometry, which was abrogated by IL10, but not IL6, neutralization. TCL-CM polarized macrophages produced abundant IL-10 and were impaired in their ability to stimulate T-cell proliferation. Collectively, these results demonstrate that T-cell lymphomas promote alternative macrophage polarization in an IL-10 dependent manner, and both CD163 and pSTAT3 may aid in their identification in clinical T-cell lymphoma specimens. Therefore, CD163+/pSTAT3+ macrophages were visualized by immunofluorescence in PTCL, NOS specimens. IL-10 polarized macrophages were not identified in normal tissues, but were abundant constituents of the tumor microenvironment in 68% of the PTCL, NOS specimens examined (n=31). STAT3 phosphorylation in response to IL-10 is dependent upon the Janus kinases (JAK) JAK1 and TYK2, both of which are inhibited at nanomolar (and clinically achievable) concentrations by the “JAK2” inhibitor ruxolitinib. Therefore, we sought to determine whether ruxolitinib may prevent IL-10-induced macrophage polarization. As expected, ruxolitinib inhibited IL-10-induced STAT3 phosphorylation. More importantly, macrophages polarized in the presence of ruxolitinib lost the immunophenotype characteristics of IL-10 polarized macrophages, and were CD16-/loCD163-/loHLA-DRhi. Furthermore, IL-10 production was significantly impaired in macrophages polarized in the presence of ruxolitinib, while their ability to stimulate T-cell proliferation was significantly increased. In a separate initiative, we identified GATA3 as the key regulator of IL-10 and Th2 cytokine (IL-4, IL-13 and IL-5) expression in T-cell lymphoma lines by shRNA knockdown assays. Therefore, we examined GATA3 expression by immunohistochemistry in PTCL, NOS specimens. GATA-3 expression was observed in most of the T-cell lymphoma lines and in 47% of PTCL, NOS specimens (n=76). In the cohort of the 76 PTCL, NOS patients, the median PFS and OS observed in GATA3+ PTCL, NOS was 5 months (4-8 months, 95% CI) and 8 months (5-14 months, 95% CI), respectively. In contrast, the median PFS and OS in GATA3- PTCL, NOS was 1.3 years (0.6-1.6, 95% CI) and 1.6 years (0.7-6.9 95% CI), respectively. Conclusions Alternatively polarized macrophages are abundant in T-cell lymphomas and are generated in an IL-10- and STAT3-dependent manner. GATA-3 regulates IL-10 production in these lymphomas, and its expression identified a high-risk subset of PTCL, NOS with distinct clinicopathological features. As IL-10-dependent STAT3 phosphorylation and macrophage polarization were impaired by ruxolitinib, the JAK2 inhibitors may warrant closer scrutiny as immunomodulatory agents. Disclosures: Off Label Use: Ruxolitinib, a JAK2 inhibitor, may warrant closer scrutiny as an immunomodulatory agent in TCL therapeutics.

Abstract Background Relatively few studies have evaluated the role of host (germline) genetics in predicting outcome in diffuse large B-cell lymphoma (DLBCL), and of these, most were small candidate gene studies without replication and/or from the pre-R-CHOP era. We report the first genome-wide association study (GWAS) of outcome in DLBCL patients treated with rituximab and anthracycline-based chemotherapy. We used two independent studies for discovery, and validated the results in two additional independent studies. Methods In the discovery phase, we conducted a meta-analysis of two GWAS studies of DLBCL patients treated with rituximab and anthracycline-based chemotherapy, the first study as part of the prospective clinical trials of the LNH2003B program (N=540) of the Lymphoma Study Association (LYSA) and the second as part of the Molecular Epidemiology Resource (N=316), a prospective observational study from the University of Iowa/Mayo Clinic Lymphoma Specialized Program of Research Excellence (SPORE). Genotyping for the GWAS was performed using the Illumina 610 (LYSA) and 660 Quad (SPORE) BeadArrays (Illumina, San Diego, USA). HapMap2 was used to impute additional SNPs. Association testing was conducted assuming a log-additive genetic model and using Cox regression analyses. We calculated the hazard ratios (HRs) and 95% CIs for event-free survival (EFS), with adjustment for age, sex and age-adjusted IPI. The two studies were then combined using the fixed effects inverse variance method based on the beta estimates and standard errors from each study. From the meta-analysis, 89 SNPs were selected for validation, based on a minor allele frequency (MAF) >0.05 and LD pattern for multiple SNPs from the same region. Validation cohorts were an independent set of DLBCL patients from the SPORE (SPORE-2, N=366) and DLBCL patients from the prospective GOELAMS 075 phase III study (N=294), and validation genotyping was conducted using the Illumina VeraCode platform. We then conducted a meta-analysis of the 4 studies. We report SNPs with both a statistical significance of p<5x10-6 and effect sizes in the same direction across the 4 studies in the meta-analysis. For the latter SNPs, we also report the results for overall survival (OS), adjusted for age, sex and age-adjusted IPI. Results In the final meta-analysis of all four studies for the prediction of EFS, the top SNP was rs7765004 (MAF=0.30; HR=1.45; p=9.7 x 10-8) in the 6q21 region, which is near the MARCKS (myristoylated alanine-rich protein kinase C substrate) and HDAC2 genes. MARCKS encodes for a protein involved in cell mobility, while HDAC2 belongs to the histone deacetylase family. Additional SNPs from this region included rs6918103 (MAF=0.25; HR=1.38; p=7.6 x 10-6), which marks an EZH2 histone binding site, and rs11969684 (MAF=0.12; HR=1.43; p=3.3 x 10-5). The next hit was rs7712513 (MAF=0.31; HR=1.40; p=3.2 x 10-7), which is near arginine-fifty homeobox pseudogene 1 (ARGFXP1) on chromosome 5q23.2. This was followed by a region on chromosome 8q13.3, with the SNP rs9298183 (MAF=0.29; HR=1.41; p=1.4 x 10-6) from LOC100132891 showing the strongest association, along with 3 other SNPs from this region (rs2035376, rs6472637, and rs1600797; all p<5 x 10-6). These SNPs are near the musculin gene (MSC) a transcriptional repressor of E2A frequently silenced by promoter methylation in DLBCL. Finally, rs2253986 (MAF=0.27; HR=1.39; p=3.4 x 10-6) at chromosome 16q12.2, along with rs2253971 and rs6499810, were associated with EFS. These SNPs are located in CES5A (carboxylesterase 5A), which encodes a member of the carboxylesterase family. The family members are responsible for the hydrolysis or transesterification of various xenobiotics. The top SNPs associated with EFS also predicted OS, including rs7765004 (HR=1.41; p=1.2 x 10-5), rs7712513 (HR=1.39; p=8.4 x 10-6), rs9298183 (HR=1.36; p=3.5 x 10-5), and rs2253986 (HR=1.35; p=5.2 x 10-5). Conclusions Although our top SNPs on did not reach genome-wide significance (p<5x10-8), they showed clear consistency across the four large prospective studies and predicted both EFS and OS independently of IPI. The strongest findings were from loci on 6q21, 8q13.3, 5q23.2, and 16q12.2, and several genes from these regions are involved in methylation and xenobiotic metabolism, supporting a role for host genetic variation in these pathways in DLBCL prognosis. Disclosures: No relevant conflicts of interest to declare.

Abstract Abstract 996 Background: Treatment with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) has improved survival in diffuse large B-cell lymphoma (DLBCL) lymphoma, although a significant percentage of patients do not achieve a remission or they relapse. One potential explanation for this observation is that host pharmacogenetic background may impact metabolism, detoxification and transport of R-CHOP. However, there are few prospectively collected data that address pharmacogenetics in DLBCL, particularly for event-free and overall survival in the rituximab era. We therefore tested the hypothesis that functional candidate single nucleotide polymorphisms (SNPs) from genes involved in the metabolism of CHOP (CYP2C19, CYP3A5, ABCB1, ABCC2, ABCG2, RAC2, CYBA, NR3C1, GSTA1, GSTP1, TP53) and rituximab (FCGR2A, FCGR3A) influence prognosis in DLBCL. Methods: We genotyped 19 SNPs from 13 genes in a prospective cohort of newly diagnosed DLBCL patients with germline DNA enrolled at the Mayo Clinic and University of Iowa from 2002–2008 as part of the Molecular Epidemiology Resource of the Iowa/Mayo Lymphoma SPORE. All patients were systematically followed through 2009 for overall survival (OS) and event-free survival (EFS), defined as disease progression, retreatment or death due to any cause. All SNPs were genotyped on the Illumina Golden-Gate platform. Cox regression was used to estimate Hazard Ratios (HRs) and 95% confidence intervals (CI) for individual SNPs with OS and EFS. Each SNP was modeled with the most prevalent homozygous genotype used as the reference group. An ordinal test was used to assess the trend across genotypes, and a p<0.05 was considered statistically significant. All Cox models adjusted for International Prognostic Index (IPI) and treatment. Results: The median age at diagnosis of the 439 DLBCL patients was 62 years (range 18–92). The IPI was distributed as follows: 0–1 (34%), 2 (26%), 3 (24%) and 4–5 (16%). All patients were treated with chemotherapy, and 91% received R-CHOP. Through 2009, there were 171 events (39%) and 122 (28%) deaths, with a median follow-up for living patients of 49 months (range 1–98). The SNP rs1045642 in the ATP-binding cassette (ABC) protein gene ABCB1 was associated with OS (p=0.012). The variant T allele for ABCB1 rs1045642 (minor allele frequency (MAF)=0.47) is associated with a silent I→I substitution, and the T allele predicts low enzyme expression. Compared to CC homozygotes, patients with CT (HR=0.66, 95% CI 0.44–0.99) or TT (HR=0.53, 95% CI 0.31–0.90) genotypes had superior OS. We also observed an association of the GSTP1 SNP rs1695 with OS (p-trend=0.018). The variant G allele (MAF of 0.31) is associated with an A→V substitution, and this change predicts low enzyme expression. Compared to AA homozygotes, patients with the AG (HR=0.78, 95% CI 0.54–1.14) or GG (HR=0.39, 95% CI 0.17–0.90) genotypes had superior OS. Nearly identical associations for these two SNPS were observed with EFS. There were no significant associations with any of the other SNPs that we evaluated. Conclusions: In a large series of newly diagnosed DLBCL patients treated in the rituximab era, we found evidence that genetic variation in ABCB1 and GSTP1 is associated with improved OS and EFS after adjusting for IPI and treatment. The variant allele for ABCB1 is associated with slower enzyme activity, favorably impacting doxorubicin and vincristine pharmacodynamics, and the variant allele for GSTP1 is associated with slower detoxification of doxorubicin and vincristine, increasing bioavailability of these drugs. A comprehensive evaluation of the role of pharmacogenetics in DLBCL is warranted. Support: P50 CA97274, R01 CA129539. Disclosures: No relevant conflicts of interest to declare.

Abstract Background: Monoclonal gammopathy of undetermined significance (MGUS) is reported in 3 to 5 percent of population, with the prevalence increasing with advancing age. Patients with MGUS are at increased risk for progression to multiple myeloma or other plasma cell dyscrasias. There is a paucity of information on clinical outcomes of patients with MGUS undergoing renal transplantation. A retrospective study was performed to determine wether MGUS is a contraindication to renal transplantation. Methods: Data was collected from both the kidney transplant and MGUS database. The diagnosis of MGUS was made on the basis of either serum protein electrophoresis (SPEP) or immunofixation after excluding multiple myeloma, amyloidosis and monoclonal immunoglobulin deposition disease. Results: Between 1977 and 2004, 3518 patients underwent kidney transplantation of whom 23 patients had a preexisting monoclonal gammopathy of undetermined significance (MGUS). Fourteen (61%) of these patients were males. The median age at the time of transplant was 59 ±12 years. Ten patients (43.5%) had IgG Kappa (GK), 7 (30.4%) had IgG Lambda (GL), 2 (8.7%) had IgA Lambda (AL), 1 (4.3%) had IgA Kappa (AK), 2 (8.7%) had IgM Lambda (ML). One patient had a biclonal gammopathy GL and ML. Patients were monitored with either SPEP or immunofixation for median duration of 1542 days after transplantation. Thirteen patients had either no change or stable monoclonal protein, 6 had a decrease in their paraprotein level. Two patients had a mild increase in their paraprotein. Two patients with GK developed into biclonal gammopathy (GK and AK). The median follow up of this cohort after the renal transplant was 1783 days. Twelve (52%) patients remained alive at the time of the study. A patient with GK prior to the transplant who underwent kidney transplantation twice developed a biclonal gammopathy and was found to have increased plasma cells (20%) in bone marrow after 14 years. On follow up for 6 years, his M-protein remained stable. Another patient was found to have 17% plasma cells around the time of kidney transplantation. He had a stable M-protein at follow-up, but underwent a stem cell transplant for recurrent immunotactoid glomerulonephritis. Two (9%) patients developed more than 15% plasma cells in their bone marrow with a stable M-protein. None of the patients with a preexisting MGUS evolved into multiple myeloma. Conclusion: In this small study, the presence of MGUS prior to kidney transplantation did not appear to have increased the incidence of multiple myeloma post transplant. Therefore, MGUS by itself should not be considered as an absolute contraindication for renal transplantation.

Abstract T cell lymphoma (TCL) is a heterogeneous group of malignant lymphomas and is subdivided in three major subgroups, (i) cutaneous (mycosis fungoides (MF), sezary syndrome (SS) and primary CTCL), (ii) nodal (peripheral T-cell lymphoma, PTCL NOS, anaplastic large cell lymphoma (ALCL), angioimmunoblastic (AITL)) (iii) and extranodal. Because of this broad morphological spectrum and immunophenotypic variation the pathogenesis of most of the TCL is poorly understood. Constitutive STAT3 signaling provides growth-promoting signals in many forms of malignancy; however in-vivo activation of phosphorylated STAT3 and its clinical correlation in subtypes of TCLs has not been extensively studied. In this study we examined constitutive STAT3 activation in various subtypes of TCL tumors and performed pre-clinical testing to determine whether STAT3 inhibitors will be effective. First, we assessed the STAT3 activation (pSTAT3Tyr705) by immunohistochemistry (IHC) on a tissue microarray (TMA) from 169 untreated TCL patient samples. Using a cutoff of ≥30% pSTAT3 nuclear staining, 38% (64/169) of TCL tumors were pSTAT3+. Interestingly, pSTAT3 was differentially expressed among the various TCL subgroups. 27% (16/59) PTCL NOS, 29% (11/38) AITL, 93% (14/15) ALK+ ALCL, 57% (13/28) ALK- ALCL, 50% (6/12) extranodal NK/T cell tumors and 17% (1/6) primary cutaneous showed pSTAT3 positivity. Using either a 30% or 80% cut-off, pSTAT3 positivity was associated with inferior event free survival for AITL, PTCL NOS and ALK neg ALCLs TCLs. Due to small sample size within each group statistical significance (p=0.03) was met only for ALK neg ALCL (80% cutoff). Further analysis in the human TCL cell lines and normal control T-cells also revealed differential expression of pSTATs. ALCL cell lines, Karpas 299 and SR786 were pSTAT3 positive but pSTAT5 negative. Both the CTCL (SS) cell lines HuT78 and SeAx were pSTAT3 negative, however MyLa a cell line of MF origin was strongly pSTAT3+ and pSTAT5+. The normal control CD4 T-cells was pSTAT3- and pSTAT5+. These data clearly suggest that pSTAT3 is differentially expressed among the TCL tumors and is a potential therapeutic target. Potential mechanisms for STAT3 activation could be aberrant secretion of cytokines/chemokines produced by the tumor itself or the tumor microenvironment. We compared the cytokine profile of the culture supernatant from pSTAT3 positive SUDHL1 and pSTAT3 negative HuT78 TCL cell lines using a 30-plex ELISA. The most significantly different cytokines among these 2 cell lines were interleukin -10 (IL-10) and soluble interleukin-2 receptor alpha (sIL-2Ra). The SUDHL1 was found to secrete a very high level (1700 pg/ml) of IL-10, in contrast to only 167 pg/mL in the HuT78 supernatant. Moreover, SUDHL1 secretes 3.5 times more sIL-2Ra (6600 pg/ml) than the pSTAT3 negative cell line HuT78 (1800 pg/ml). In-vitro exposure to IL-10 but not sIL-2Ra was able to further upregulate pSTAT3 in SUDHL1 and Karpas 299. Overall, these data suggest that autocrine secretion of IL-10 but not sIL-2Ra is important for STAT3 activation in ALCL TCLs. Next we compared the cytokine profile of 2 pSTAT3 positive cells from different origin; SUDHL1 (ALCL) and MyLa (MF). In contrast to SUDHL1 (which produce high level of IL-10), MyLa was producing very little IL-10 (18pg/ml). The other most significantly different cytokines between these cells was RANTES with MyLa producing a very high level (28897 pg/ml) and SUDHL1 a very low level (8pg/ml). We also noticed differential level of IL-13 between these cells; MyLa producing 113pg/ml while SUDHL1 only 13 pg/ml. SAR302 (Sanofi, Cambridge, MA), a selective JAK2 inhibitor currently in clinical trial for myeloproliferative neoplasms was able to inhibit autocrine secretion of IL-10 but not sIL-2Ra in a dose-dependent manner followed by STAT3 dephosphorylation and decreased lymphoma cell survival. In summary, our data provide first evidence of in-vivo STAT3 activation in AITL, PTCL NOS, ALK negative ALCL TCLs using TMA from patient samples. Comprehensive cytokine analysis determined IL-10 as an autocrine factor driving STAT3 activation in ALCLTCLs, while RANTES and IL-13 might be important drivers for STAT3 activation in MF TCLs. Finally our data provide a mechanistic basis of selecting and targeting TCL tumor cells with high IL-10 levels and/or constitutive STAT3 activity with potent and novel JAK2 inhibitors such as SAR302 or other STAT3 inhibitors. Disclosures: No relevant conflicts of interest to declare.

Abstract We have recently reported that event-free survival at 24 months from diagnosis (EFS24) is a robust endpoint for assessment of disease related outcome for newly diagnosed patients with diffuse large B-cell lymphoma (DLBCL) treated with anthracycline-based immunochemotherapy (IC). Patients who achieve EFS24 following IC have a subsequent overall survival that is equivalent to the age and sex matched general population. The IPI was developed in the pre-rituximab era using OS/EFS endpoints. While the IPI is associated with outcome in the IC era, the original survival estimates for the IPI risk groups are outdated. The IPI is also a discrete risk classifier, with only 6 possible groups. Here we remodel the IPI using EFS24 as the endpoint in a large international cohort of patients treated with IC. This model provides an individual level 0-100% risk of failing to achieve EFS24 for each patient and can be used for patient prognosis, treatment stratification, and risk assessment. Methods Newly diagnosed DLBCL patients treated with immunochemotherapy from the University of Iowa/Mayo Clinic SPORE Molecular Epidemiology Resource, NCCTG N0489 clinical trial, GELA LNH2003B program, and a Lyon, France based hospital registry were included in the original EFS24 study. Patients with a relapse, progression, unplanned re-treatment, or death due to any cause within 730 days of diagnosis were considered a failure for the EFS24 endpoint. Patients alive and progression/relapse free at 730 days from diagnosis with no subsequent treatment following initial IC were considered a success for the EFS24 endpoint. Variables selected for potential model inclusion were the IPI components (age, stage, ECOG PS, number of extranodal sites, and LDH), as well as standard clinical variables typically reported in studies of DLBCL: presence of B-symptoms, bone marrow involvement, bulky disease (>10 cm), and sex. The IPI24, a prognostic model for EFS24, was developed using logistic regression models. Model building began by fitting the classic IPI score (0-5), then allowing individual IPI variables to carry different model weights and number of categories, followed by dropping insignificant variables, finally adding any additional significant variables. Model performance was assessed using bias corrected c-statistics, AIC, and R2 values. Model selection was done using the complete case set with multiple imputation on the full dataset used to refine parameter estimates for the final model. Results 1596 total patients were available for modeling. The median age was 62 (range 18-93) and 53% were male; 33% were IPI 0-1, 25% were IPI 2, 25% were IPI 3, and 17% were IPI of 4-5. The failure rate for achieving EFS24 was 29%. All variables but sex (p=0.33) were univariately associated with EFS24 (p<6.4x10-5). The original IPI had good prognostic ability for EFS24 (c=0.696, p=2.2x10-32). Allowing multiple categories for ECOG PS, stage, and age (continuous) improved model fit and prognostic ability (c=0.727). The number of extranodal sites was not significant when IPI variables were modeled separately and was removed from the model. Sex and bulky disease were additional significant variables when added to the model. Thus, the final IPI24 model contained the following risk predictors: male sex, ECOG PS (0 vs. 1 vs 2 vs 3-4), stage (I vs. II, vs. III vs. IV), LDH (elevated vs. normal range), bulky disease > 10cm, and age (continuous). This model resulted in improved fit and prognostic ability (c=0.749) over the standard IPI (c=0.696, bootstrap p<0.001). Model validation was performed on an additional 158 patients from the SPORE MER and showed good concordance (c=0.697). Additional validation is planned in a larger set of independent patients. Conclusion The IPI24, generated using standard clinical variables, yields an individual risk prediction for failing to achieve EFS24 following IC for treatment of DLBCL. The IPI24 has superior prognostic ability to the standard IPI and can be implemented in the clinic using a nomogram or as a simple electronic application. Disclosures: No relevant conflicts of interest to declare.

Abstract Background Despite improvements in outcome following the addition of rituximab (R) to CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) (R-CHOP), patients with newly diagnosed diffuse large B-cell lymphoma (DLBCL) and International Prognostic Index (IPI) scores of 3-5 at diagnosis have a poor outcome. Enzastaurin is a potent inhibitor of PKCβ, a component of the B-cell receptor signaling complex, with preclinical activity and clinical activity in a phase II trial in patients with relapsed DLBCL, providing the rationale for this study in the primary therapy setting. Methods PRELUDE was a multi-national, randomized, double-blinded, placebo-controlled study. Patients were required to have a histologic diagnosis of DLBCL, pre-treatment IPI score ≥3, and a complete response (CR) or CRu by International Working Group Criteria, or a negative FDG-PET scan after 6–8 cycles of R-CHOP. Patients were randomly assigned in a 2:1 ratio to receive either enzastaurin 500 mg daily or an identical placebo as maintenance therapy, for a planned treatment duration of 3 years. The primary endpoint was DFS, defined as lack of disease progression or death. Assuming a 2-year DFS rate in the control group of 70%, the primary analysis had 80% power to detect a HR of 0.67, eg, a 2-year DFS rate of 79% in the enzastaurin group. Secondary endpoints included overall survival (OS) and event-free survival (EFS). Data were analyzed 3 years after the last enrolled patient initiated treatment. Results From May 2006–April 2010, 758 patients were enrolled (enzastaurin, n=504; placebo, n=254). Median age at enrollment was 64 years (range 21-89); at diagnosis, 65% of patients had stage IV disease, 48% had B symptoms, and 25% had a mass >10 cm; baseline disease and patient characteristics were well balanced between treatment arms. Fifty-seven percent had a negative PET scan following completion of R-CHOP. Median follow-up time for all patients was 48 months (range 0.03–80). At the time of analysis, 209 events had occurred. The DFS HR for enzastaurin vs. placebo was 0.92 (95% CI: 0.69, 1.22; 2-sided log-rank p=0.54). DFS at 24 and 48 months were 79% and 70% for the enzastaurin arm, and 75% and 71% for placebo, respectively. OS at 24 and 48 months was 87% and 81% for enzastaurin, and 89% and 82% for placebo; HR for enzastaurin vs. placebo was 1.04 (95% CI: 0.74, 1.47; 2-sided log-rank p=0.81). Percent of ITT population patients on therapy at 12, 24, and 36 months was 70.6%, 60.6%, and 20.1% for enzastaurin; 72.3%, 60.6%, and 22.1% for placebo. Biomarker subgroup analysis was performed and will be available at time of presentation. Treatment emergent AEs (all grades) that were possibly study drug-related and significantly different between enzastaurin and placebo included chromaturia (18.5% vs. 0.4%), QTc prolongation (10.8% vs. 3.6%), and diarrhea (10.3% vs. 2.8%). There were no significant differences in number of patients with at least 1 grade 3 or higher AE between treatment arms. No significant differences were observed in the frequency of deaths while on therapy. Conclusion Enzastaurin did not improve DFS, EFS, or OS in patients with high-risk DLBCL and CR following R-CHOP treatment. Disclosures: Crump: Roche: Honoraria; Jansen-Ortho: Honoraria; Celgene: Honoraria; Lundbeck: Honoraria; Novartis: Research Funding; Seattle Genetics: Honoraria. Off Label Use: rituximab for maintenance therapy post autolgous transplant for lymphoma. Leppä:Eli Lilly: Research Funding. Ogura:Eli Lilly: Research Funding. Rifkin:Millenium, Celgene, ONYX: Membership on an entity’s Board of Directors or advisory committees. Mackensen:Eli Lilly: Consultancy. Offner:Eli Lilly: Membership on an entity’s Board of Directors or advisory committees. Smith:Genentech, Celgene, Spectrum, Seattle Genetics, Gilead, Amgen/Micronet: Consultancy. Tobinai:Eli Lilly: Research Funding. Hahka-Kemppinen:Eli Lilly: Employment. Thornton:Eli Lilly: Employment. Shi:Eli Lilly: Employment. Lin:Eli Lilly: Employment. Kahl:Genentech: Consultancy. Savage:Eli Lilly: Consultancy.

Abstract Abstract 1640 Background: The introduction of radioimmunotherapy (RIT) into clinical practice for the treatment of follicular lymphoma (FL) occurred at a time at which many patients did not have prior exposure to rituximab. Clinical trials in the relapsed/refractory setting, as well as consolidation in the upfront setting have included a small number of patients that had been previously treated with rituximab or a rituximab containing treatment regimen. We evaluated the effect of prior rituximab therapy on the efficacy of RIT. METHODS: The prospective lymphoma database was queried for all patients having received a single dose of yttrium-90 ibritumomab tiuxetan for relapsed/refractory FL which had previously been treated with systemic therapy (patients receiving only prior external beam radiation therapy were excluded). The database includes all consecutive adult patients diagnosed with lymphoma seen at Mayo Clinic Rochester. The diagnosis of follicular lymphoma was as by WHO classification and centrally reviewed. Patients with evidence of histologic transformation to diffuse large B cell lymphoma prior to RIT were excluded. Time to treatment failure (TTF) was defined as the time from RIT to next anti-lymphoma therapy. RESULTS: 111 patients were identified. 57 (51%) were male. Median age at time of RIT was 58 (19–88). Median time from diagnosis to RIT was 35 (6–281) months in patients having received prior treatment with rituximab and 47 (12–272) months in those who had not (p=0.19). 63 (57%) of patients received prior treatment with rituximab or rituximab containing chemotherapy. Median number of prior therapies was 2 (1–10), which was not different between the rituximab treated or untreated groups [2(1–6) vs 2(1–10) p=0.12]. Median TTF was 10.0 months in the patients having received prior rituximab and 10.1 months in those that had not (p=0.29). Figure 1. The median overall survival from RIT was not reached, but appeared similar (Kaplan-Meier estimate 125 months without prior rituximab exposure vs 95 months with prior rituximab exposure; p=0.33). CONCLUSIONS: Prior rituximab exposure does not seem to adversely impact the time to treatment failure or overall survival in those patients treated with RIT. While the data leading to the approval of RIT were accrued prior to the routine clinical use of rituximab, our data demonstrate similar clinical benefit of RIT in patients with prior exposure to rituximab or rituximab containing therapy. Disclosures: No relevant conflicts of interest to declare.

Abstract Abstract 991 Background: The outcome of patients with DLBCL has significantly improved with the addition of rituximab to CHOP chemotherapy. While standard clinical prognostic factors such as those included in the International Prognostic Index (IPI) still predict outcome in DLBCL in R-CHOP treated patients, predicting the outcome of patients might be further refined using biological factors. We therefore tested whether pretreatment serum cytokines, that measure the biological activity of the tumor as well as the host response, could provide additional prognostic information in DLBCL patients. Methods: Newly diagnosed DLBCL patients were prospectively enrolled in the University of Iowa/Mayo Clinic SPORE Molecular Epidemiology Resource (MER). Serum cytokines were measured from pre-treatment blood draws using a multiplex ELISA (Upstate Cell Signaling Solutions, Lake Placid, NY). Thirty cytokines, including pro-inflammatory, Th1 and Th2 associated cytokines, were analyzed using the Luminex-100 system Version 1.7 (Luminex, Austin, TX). Data analysis was performed using the MasterPlex QT 1.0 system (MiraiBio, Alameda, CA). The assay was also performed on research serum draws from 400 non-lymphoma epidemiology controls enrolled on a corresponding lymphoma etiology case-control study. The upper limit of normal for each cytokine was defined as the 95th percentile from the control distribution. Clinical data was abstracted using a standard protocol for the MER and patients were followed systematically for event-free (progression, retreatment, or death due to any cause) and overall survival (EFS and OS, respectively). Cox proportional hazards models were used to evaluate the association between cytokines and outcome. Principal components analysis (PCA) was performed on the combined DLBCL and control cytokine dataset, agnostic to clinical characteristics and outcome, to identify cytokine profiles. Results: 206 DLBCL patients diagnosed between September 2002 and February 2008 with available serum were included. The median age was 64 years (range 20–92) and 52% were male. At a medium follow-up of 47 months (range 5–94), 75 patients (36%) had relapsed and 63 patients had died (31%). A cytokine profile was determined based on the first two principal components (PC) of the PCA analyses with PC1 corresponding to a general (host) cytokine elevation (also seen in normal controls) and PC2 corresponding to an increase predominantly in cytokines that were commonly elevated in DLBCL patients. 75 DLBCL patients (36%) had a normal cytokine profile similar to the general population of controls; 114 DLBCL patients (55%) had elevation in tumor specific cytokines (CXCL10, CXCL9, IL-2R, IL-12, IL-8, and IL-10) and 17 (8%) had a general cytokine elevation. Patients with any elevation of cytokines (tumor specific or general elevation) had a significantly worse event-free (HR=3.96, 95% CI: 2.13–7.37, p<0.00001) and overall survival (HR=3.75, 95% CI: 1.99–7.09, p<0.0001) than those with a normal cytokine profile (see figure). While the cytokine elevations were associated with advanced stage, poor performance score and elevated LDH, they were not associated with advanced age or extranodal disease and the results remained significant after adjustment for the IPI and treatment in the Cox model (EFS HR=3.11, 95% CI: 1.66–5.85, p<0.0001; OS HR=2.93, 95% CI: 1.53–5.63, p=0.001). Elevated serum cytokines also identified patients who were unlikely to complete initial therapy or who relapsed early. In low-risk patients (IPI 0–2), only 3% of patients with normal serum cytokines relapsed in the first 12 months compared to 23% of patients with elevated cytokines. Similarly in the high-risk group (IPI 3–5), none of the patients with normal cytokines relapsed in the first year compared to 43% with elevated cytokines. Conclusion: Elevated pretreatment serum cytokines, predominantly related to the malignancy, are associated with an increased likelihood of disease relapse and an inferior survival in patients with DLBCL. Furthermore, the pretreatment cytokine profile may also identify DLBCL patients at high risk for early disease relapse. Disclosures: No relevant conflicts of interest to declare.