Ansell, Stephen M.

Abstract The lymphocyte-to-monocyte ratio at diagnosis (LMR-D) has been reported to be a prognostic factor for clinical outcomes in both T-cell and B-cell lymphomas. However, there are no reports testing the prognostic ability of LMR-D in patients diagnosed with de novo double/triple hit diffuse large B cell lymphoma (DLBCL). Thus, we set out to investigate if the LMR-D is a prognostic factor for survival in de novo double/triple hit lymphomas. From 10/5/1998 until 1/16/2015, thirty-four patients with de novo double/triple hit DLBCL were identified for this study. Double and triple hit were defined by interphase FISH evaluating three fusion signals to identify the BCL2 translocation and IGK/MYC D-FISH probe to identify whether the partner is IG or non-IG. Interphase fluorescence in situ hybridization (FISH) was performed on paraffin sections using probes that included 8q24 (5'MYC, 3'MYC); t (2;8), IGK/MYC; t(8,14), MYC/IGH; t(8;22), MYC/IGL; 3q27 (3'BCL6, 5'BCL'6); and 18q21 (3'BCL2, 5'BCL2). The cohort included 14 females and 20 males. The median follow-up for the cohort was 9.0 months (range: 0.4-72.6 months). Using the median for the LMR-D as the cut-off value, patients with a LMR-D ≥ 1.2 experienced superior overall survival (OS) [Hazard ratio (HR) of 0.127, 95% confidence interval (CI) of 0.019-0.530, p < 0.004] and progression-free survival (PFS) [HR of 0.107, 95 CI of 0.024-0.335, p < 0.0001]. The median follow up for OS for patients with a LMR-D ≥ 1.2 was not reached with a 5-year OS rate of 82% (95% CI of 49%-95%) compared with a median follow-up of 10 months for patients with a LMR-D < 1.2 with a 0% 5 year OS rate, p < 0.003 (Figure 1A). The median PFS for patients with a LMR-D ≥ 2 was not reached with a 5 years PFS of 74% (95%CI, of 43%-91%) compared with a median follow-up of 4.7 months for patients with a LMR-D < 1.2 and 0% 5 year PFS rate, p < 0.0001 (Figure 1B). After adjusting for the International Prognostic Index, multivariate analysis showed that the LMR-D remained an independent prognostic factor for OS [HR = 0.180, 95% CI of 0.254-0.784, p < 0.02] and for PFS [HR of 0.127, 95%CI of 0.029-0.409, p < 0.0003]. In spite of the small cohort of de novo double/triple hit DLBCL, the LMR-D was identified as a prognostic factor for clinical outcomes for this specific set of aggressive lymphomas. Further studies are warranted to confirm our findings. Table.LMR-D ≥ 1.2, N = 18Events = 2LMR-D < 1.2, N = 16Events = 8P < 0.003LMR-D ≥ 1.2, N = 18Events = 3LMR-D < 1.2, N = 16Events = 14P < 0.0001Figure 1AB Figure 1. Figure 1. Disclosures Maurer: Kite Pharma: Research Funding. Ansell:Bristol-Myers Squibb: Research Funding; Celldex: Research Funding. Off Label Use: New agent in a combination regimen..

Abstract Background: Treatment of Hodgkin lymphoma (HL) requires a careful balance between providing enough therapy to cure the disease and avoiding unnecessary treatment that could result in excessive long-term treatment-related complications. The preferred treatment option for limited stage non-bulky HL currently involves the use of combined chemotherapy and involved-field radiation therapy. Given the unclear overall survival advantage and the long-term side effects associated with consolidative radiation, the use of this modality remains one of the most controversial topics in the treatment of HL. Therefore, alternative consolidation approaches are worthy of exploration for treatment of limited stage non-bulky HL. Brentuximab vedotin has been associated with favorable response rates in patients with relapsed or refractory HL. We hypothesize that brentuximab vedotin may be safe and effective in eradicating residual disease after induction chemotherapy and may potentially replace radiation therapy for consolidation in patients with newly diagnosed limited stage non-bulky HL. Methods: In this phase 2 multicenter study, patients with non-bulky (< 7.5 cm) stage I or II HL are being enrolled to determine the efficacy and safety of brentuximab vedotin when administered for consolidation after a standard chemotherapy with ABVD (doxorubicin, bleomycin, vinblastine, and dacarbazine) (ClinicalTrials.gov #NCT01578967). The primary objective of the study is to estimate the proportion of patients who achieve PET-negative disease (Deauville score of 2 or less) after induction chemotherapy followed by consolidation with brentuximab vedotin. Involved-field radiation is recommended only if the PET scan is positive at the completion of therapy with brentuximab vedotin. Patients received 2 to 6 cycles of ABVD based on their baseline risk factors and the interim PET scan result; patients with favorable disease with negative interim PET received 2 cycles, favorable disease with positive interim PET or unfavorable disease with negative interim PET received 4 cycles, and unfavorable disease with positive interim PET received 6 cycles of ABVD. Approximately 6 to 8 weeks after the induction chemotherapy, 1.8 mg/kg of brentuximab vedotin was given every 3 weeks for 6 cycles for consolidation. Results: Interim analysis was performed per protocol for futility and safety after 15 evaluable patients were enrolled since April 2012. Out of 15 evaluable patients, 8 patients have completed 6 cycles of brentuximab vedotin, and the remaining 7 patients are currently under active treatment. The median age was 28 years (range 19 – 58), and 7 patients (47%) presented with unfavorable disease defined by the presence of B symptoms, ESR > 50, or > 3 sites of disease. All patients had masses measuring less than 7.5 cm in diameter except one patient who requested an exception to the eligibility criteria for a conglomerate mediastinal mass measuring 10 cm. No grade 3 or above adverse events have been observed with brentuximab vedotin therapy. No grade 2 or above peripheral neuropathy or pulmonary toxicity has been reported. Ten out of 12 patients, who completed ABVD, achieved PET-negative disease after 2 cycles of ABVD, and all 7 patients who completed brentuximab vedotin achieved PET-negative disease and remain in remission with a median follow-up of 7.6 months (range 5.6 – 15). Thus far, none of the treated patients on this protocol required consolidative radiation therapy. Conclusion: In this interim analysis of 15 patients with newly diagnosed limited stage non-bulky HL, brentuximab vedotin as consolidation therapy demonstrates promising safety and clinical activity following ABVD. Enrollment is currently open with the target accrual of 40 patients to assess the feasibility of achieving PET-negative disease and thereby avoiding radiation therapy in at least 85% of patients who receive ABVD followed by brentuximab vedotin consolidation. Table: PET results in HL patients who received ABVD followed by BV Consolidation Interim-PET2 (n = 12) Post ABVD (n = 12) Post BV (n = 7) Deauville 1 0 1 4 Deauville 2 10 11 3 Deauville 3 2 0 0 Deauville ≥ 4 0 0 0 PET, positron emission tomography; HL, Hodgkin lymphoma; ABVD, doxorubicin, bleomycin, vinblastine, dacarbazine; BV, brentuximab vedotin; Interim-PET-2, PET scan after 2 cycles of ABVD; Post ABVD, PET scan after 2 to 6 cycles of ABVD; Post BV, PET scan after 6 cycles of brentuximab vedotin Disclosures Park: Seattle Genetics: Research Funding; Teva: Research Funding; Janssen: Travel, Travel Other. Off Label Use: Brentuximab vedotin in previously untreated Hodgkin lymphoma patients.

Abstract Background: While B-cell receptor (BCR) signaling is essential for the development, of normal B cells, its aberrant hyper-activation results in neoplastic transformation of B-lymphocytes. Recent investigations using small molecule inhibitors validate the BCR pathway as a valuable target. Bruton’s tyrosine kinase (BTK) is one of the components of a signaling hub that transduces signals from the BCR into the cell for its activation and has been shown to be a therapeutic target. Ibrutinib (PCI-32765), an irreversible BTK inhibitor has shown clinical efficacy in CLL, mantle cell lymphoma (MCL) and Waldenströms macroglobulinemia (WM). Ibrutinib binds to cysteine-481 of the BTK protein and blocks its phosphorylation, resulting in termination of BCR-mediated activation of cells with a concomitant induction of death. Despite the clinical success of ibrutinib, a high percentage of patients achieve only partial response and eventually acquire resistance to the drug, resulting in aggressive relapse of the disease. A mutation of Cys481-Ser in BTK (ibrutinib-BTK binding site) has been reported to be one of the reasons for the development of ibrutinib resistance (IR). To understand the mechanisms resulting in acquisition of IR, we developed preclinical models of IR in WM and MCL. Materials: Ibrutinib was obtained from Pharmacyclics, CA. Validated human WM models (BCWM.1, RPCI-WM1 and MWCL.1 cell lines) and human MCL models (Jeko-1 and Maver cell lines) were used for the study. Results: BTK was constitutively phosphorylated at Y223 and Y551 in all the cell lines tested and this was inhibited by ibrutinib in a dose dependent manner. Phosphorylation of other kinases in the cascade such as SYK (Y323 and Y525/526) and PLCg2 (Y759 and Y1217) were also inhibited while AKT phosphorylation at both Ser473 and Thr308 was consistently increased in presence of ibrutinib. Treatment with ibrutinib induced cell cycle arrest in the G1 phase by 24h followed by apoptosis. Cell growth assays (MTS assay) showed that BCWM.1 was the most sensitive cell line followed by MWCL-1, RPCI-WM1, Maver and Jeko-1. Exposure of WM and MCL cells for prolonged periods of time with progressively increasing concentrations of ibrutinib resulted in outgrowth of clones (IR WM and MCL cell lines) that were resistant to apoptosis with a slow growth rate as compared to wild type parental cells. IR cells attained 2 – 20 fold resistance to ibrutinib as compared to the respective parental lines as determined by MTS assay. Sequence analysis of the BTK gene in all the cell lines revealed no mutation in IR cells at Cys481 suggesting that in an acquired IR state, resistance to ibrutinib can be developed independent of BTK Cys481 mutation. Interestingly, we found p-BTK levels to be markedly reduced in IR cells. Ibrutinib reversal experiments suggested that while a continuous presence of ibrutinib is needed for inhibition of BTK phosphorylation, a stable IR state could be maintained (for >1 month) in the absence of ibrutinib. This suggested the cells reliance on a parallel survival pathway, independent of BTK phosphorylation. Focused mRNA (Nanostring nCounter assay) and immunoblot analysis revealed significant changes in the expression profiles of several cellular elements. These included transcription factors such as PU.1, IRF4, BLIMP1, BCL-6 b-catenin as well as the phosphorylated ERK1/2, STAT1 and 3 suggesting a reprogramming of critical cellular networks, which IR tumor cells might be utilizing to overcome ibrutinib-induced cytotoxicity. Importantly, we observed that IR cells retained high levels of p-AKT and showed an increase in expression of BCL2 family members, as well as BCL-2 itself. Treatment of IR cells with ibrutinib +/- MK2206 (AKT inhibitor), or ABT-199 (BCL-2 inhibitor), synergistically induced cytotoxicity in IR cells, suggesting the importance of these parallel survival pathways (AKT/BCL2) in maintaining an IR state. Conclusion: Here we demonstrate that in the absence of BTK Cys481 mutation, an IR state is associated with reprogramming of transcriptional networks countering ibrutinib-induced toxicity by activation of AKT and BCL-2. Our current data exposes multiple vulnerabilities within IR cells, which can be therapeutically exploited to potentially delay onset of IR, by targeting alternative oncogenic mechanisms that are activated in presence of sustained BTK inhibition. Disclosures No relevant conflicts of interest to declare.

Abstract Background: Follicular lymphoma (FL) is the second most common nodal lymphoma worldwide and remains incurable for most patients (pts). FL is recognized to be a highly heterogeneous disease and a subset of pts experience remarkable poor outcome. In a recent study, 19-26% of pts receiving first-line R-CHOP experienced progression of disease (POD) within 24 months after diagnosis and had a 5-year (yr) overall survival (OS) of only 34-50%, as compared to a 5-yr OS of 90-94% for pts without POD within 24 months (Casulo et al., J Clin Oncol 2015). Consequently, event-free survival at 12 (EFS12) and 24 months (EFS24) have been suggested as novel surrogate endpoints for poor overall survival in clinical trials and useful for patient counseling (Maurer et al., ASH 2014). We have previously shown that a clinicogenetic risk model (m7-FLIPI) that includes the mutation status of seven genes (EZH2, ARID1A, MEF2B, EP300, FOXO1, CREBBP, and CARD11), the FL International Prognostic Index (FLIPI), and the Eastern Cooperative Oncology Group (ECOG) performance status, improves risk stratification for failure-free survival (FFS) and OS in pts with FL receiving first-line immunochemotherapy (Pastore et al., Lancet Oncology 2015). An online tool is available at: http://www.glsg.de/m7-flipi. It would be advantageous to determine prognosis prior to front-line therapy rather than after POD. Thus, we aimed to investigate the predictive utility of the m7-FLIPI for early POD. Patients and Methods: Clinical and mutation data were available from two independent cohorts: 151 pts who received R-CHOP and IFN maintenance as part of a randomized trial of the German Low-Grade Lymphoma Study Group (GLSG), and 107 pts from a population-based registry of the British Columbia Cancer Agency (BCCA) who received R-CVP. Among the latter, 93 (87%) received R-maintenance by intention to treat. All pts had symptomatic, advanced stage or bulky disease considered ineligible for curative radiotherapy, and a biopsy specimen obtained </=12 months prior to the initiation of first-line therapy. POD was defined as progression, relapse, or death due to any cause. POD12 and POD24 were defined based on POD status at 12 and 24 months after therapy initiation, respectively. Logistic regression analysis was performed to assess if m7-FLIPI was predictive of early POD using the statistical software R (version 3.1.2). Results: In the GLSG cohort, median age was 57 yrs (range 27-77), 51% had high-risk FLIPI, and 5-yr failure-free survival (FFS) and OS rates were 66% and 83%, respectively (median follow-up for OS 7.7 yrs). In the BCCA cohort, median age was higher (62 yrs, 37-83), but high-risk FLIPI was similarly frequent (50%); 5-yr FFS and OS rates were 58% and 74%, respectively (median follow-up for OS 6.7 yrs). A total of 43 GLSG (28%) and 24 BCCA pts (22%) were classified as high-risk by m7-FLIPI, with a 5-yr OS of 65% and 42%, respectively. In the GLSG cohort, 8 (5%) and 29 pts (19%) had POD within 12 and 24 months, respectively, 4 and 10 pts were censored before POD12 and POD24 (table). High-risk m7-FLIPI pts were significantly more likely to experience early POD with an Odds Ratio (OR) of 20.80 (95% confidence interval (CI) 3.53-395.96; p=0.0052) for POD12 and 6.33 (95% CI 2.67-15.69; p<0.0001) for POD24. Likewise, in the BCCA cohort, 16 (15%) and 28 pts (26%) experienced POD12 and POD24, respectively (table). The OR for high-risk m7-FLIPI pts was 4.69 (95% CI 1.52-14.65; p=0.0068) for POD12, and 5.36 (95% CI 2.03-14.60; p=0.0008) for POD24. In the GLSG and BCCA cohorts, the m7-FLIPI had a sensitivity of 88% and 50%, a specificity of 75% and 82%, a positive predictive value (PPV) of 16 and 33%, and a negative predictive value (NPV) of 96% and 90% to predict POD12. For POD24, sensitivity was 62% and 46%, specificity 79% and 86%, PPV 42% and 54%, and NPV 82% and 82%, respectively. Conclusion: We conclude that patients classified as high-risk m7-FLIPI are highly enriched among those with early progression of disease. However, approximately one-half of patients with progression by 24 months after therapy initiation are classified as low-risk m7-FLIPI. Thus, further efforts are needed to refine the m7-FLIPI and thereby capture additional cases that may benefit from innovative first-line approaches. Table. Population m7-FLIPI N POD12 POD24 GLSG Total 151 8/147* 29/141* High-risk 43 7 18 Low-risk 108 1 11 BCCA Total 107 16/107 28/107 High-risk 24 8 13 Low-risk 83 8 15 *Pts censored were removed Disclosures Ansell: Bristol-Myers Squibb: Research Funding; Celldex: Research Funding.

Abstract Background: Follicular lymphoma (FL) is an indolent lymphoma generally considered incurable with current standard therapies. Recent advances have resulted in prolongation of overall survival (OS) for patients with FL such that death from competing causes may now limit the mortality impact of FL in some patient groups. Identification of patients for whom FL related mortality is expected to be minimal, or conversely those at high risk of disease related mortality, is highly clinically relevant. We recently reported (Maurer et al, JCO 2014;32:1066-73) that event-free survival (EFS) at 24 months from diagnosis is a robust endpoint for disease related outcome in patients with diffuse large B cell lymphoma (DLBCL). Here we use the same approach to assess if landmark timepoints of EFS can stratify subsequent OS in FL. Methods: All newly diagnosed grade 1-3a FL patients enrolled on the University of Iowa/Mayo Clinic Lymphoma SPORE Molecular Epidemiology Resource (MER) from 2002-2011 were eligible. Patients with grade 3b FL, transformation, or presence of DLBCL at diagnosis were excluded. EFS was defined as time from diagnosis to progression, relapse, re-treatment, or death due to any cause. EFS12 was defined based on EFS status 12 months after date of diagnosis; we also assessed EFS at 24 months. OS was defined as time from a specific timepoint (diagnosis, event, or EFS12) until death due to any cause. OS was compared to age and sex matched survival in the general US population using an expected survival approach and standardized mortality ratios (SMR) and 95% confidence intervals (CI). Outcomes were examined in all patients as well as selected subsets defined by initial treatment. Replication was performed using a Lyon, France hospital registry of newly diagnosed grade 1-3a FL patients enrolled from 2002-2010 with survival compared to French population data. Results: 936 patients with grade 1-3a FL were eligible from the MER. The median age at diagnosis was 60 years (range 19-91) and 53% were male. 86% had grade 1-2 disease and 14% grade 3a disease. 23% had high-risk disease (FLIPI score ≥3). 347 (37%) were initially treated with alkylator or anthracyline based immunochemotherapy (IC), 113 (12%) rituximab monotherapy (RM), and 318 (34%) were initially observed; the remaining patients received radiation for limited stage disease (8%), chemotherapy without rituximab (4%), or other therapy (5%). At a median follow-up of 59 months (range 1-131), 403 patients (43%) had an event and 120 patients (13%) had died; 155 patients (17%) failed to achieve EFS12. From diagnosis, patients with FL had inferior OS compared to the general population (SMR=1.24, 95% CI: 1.03-1.48, p=0.018); results were similar for patients with grade 1-2 (SMR=1.23) and grade 3a (SMR=1.29) disease. The survival deficit was eliminated in patients who achieved EFS12 (SMR=0.85, 95% CI: 0.66-1.09, p=0.20, Fig 1a), and so we did not pursue modeling EFS24. In contrast, patients with a non-death event (relapse, retreatment, or progression) within 12 months of diagnosis had inferior subsequent OS (SMR=3.90, 95% CI: 2.89-5.25, p=4.8x10-19, Fig 1b). These results were replicated in 153 FL patients from the Lyon registry: patients who achieved EFS12 had equivalent subsequent OS to the general French population (SMR=0.82, 95% CI: 0.39-1.72, p=0.60, Fig 1c), while patients who failed to achieve EFS12 had poor subsequent OS (SMR=4.16, 95% CI: 1.34-12.91, p=0.013, Fig 1d). In subset analysis of the MER, patients achieving EFS12 initially treated with IC (SMR=0.98, 95% CI: 0.63-1.54, p=0.93), RM (SMR=0.66, 95% CI: 0.31-1.38, p=0.27), or observation (SMR=0.73, 95% CI: 0.47-1.15, p=0.18) had equivalent OS to the population. In contrast, for patients not achieving EFS12, OS after event was inferior for those treated with IC (SMR=15.0, 95% CI: 10.22-22.05, p=2.0x10-43) or RM (SMR=4.96, 95% CI: 1.24-19.84, p=0.023), while trending towards inferior for those initially observed (SMR=1.55, 95% CI: 0.81-2.99, p=0.19). Summary: Events within the first 12 months of diagnosis are associated with poor OS in FL, especially in patients treated with IC, while patients achieving EFS12 have excellent subsequent survival, overall and in the main treatment subsets. Prognosis for FL patients should be recalibrated at 12 months from diagnosis. EFS12 will be useful in counseling and should be considered as an endpoint in studies of newly diagnosed FL. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

Abstract Purpose: The purpose of this study was to examine whether quality of life (QOL) scores at diagnosis predict survival among patients with aggressive lymphoma, controlling for clinical variables and histological subtype. Patients and Methods: Newly diagnosed lymphoma patients were prospectively enrolled within 9 months of diagnosis in the University of Iowa/Mayo Clinic SPORE Molecular Epidemiology Resource. Eligibility criteria included age ≥18 years; exclusion criteria included HIV-positive, non-US residency, and inability to participate in an interview conducted in the English language. All pathology was reviewed by a lymphoma hematopathologist. For purposes of this analysis, we considered “aggressive lymphoma” to include the histological subtypes diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL) grade III, mantle cell lymphoma, T-cell lymphoma excluding mycosis fungoides and cutaneous types, and other (Burkitt lymphoma, high grade B-cell lymphoma NOS, grey zone, etc). Baseline QOL was measured at time of registry enrollment with the Functional Assessment of Cancer Treatment-General scale (FACT-G), which measures 4 QOL domains: physical, social/family, emotional, and functional well-being (WB); a single item Linear Analogue Self Assessment (LASA) for measuring overall QOL; and a LASA measuring spiritual WB. Patients who did not complete ≥80% of FACT-G QOL questions were excluded. Clinical data were abstracted and patients were systematically followed for event-free and overall survival (EFS, OS). QOL scores were transformed to a 0-100 scale for modeling. Generalized additive models were used to account for timing of QOL assessment in relation to treatment and diagnosis; residuals from these models were then used to assess association between QOL measures and outcome via univariate and multivariable (adjusted for IPI and subtype) Cox proportional hazards models. Results: From September 2002 to December 2009, 701 patients with aggressive lymphoma who completed baseline QOL questionnaires were enrolled and eligible for this analysis. ; Subtype was 60% DLBCL, 14% mantle cell, 11% FL grade III, 13% T-cell, and 1% other subtypes. The median age was 62 years (range 18-92), and 58% were male. At a median follow-up of 71 months (range 6-128), 316 patients (45%) had an event and 228 patients (33%) died. Patient-reported QOL was prior to therapy in 330 patients (47%) and after initiation of therapy in 371 (53%). The median overall FACT-G total score was 83 (IQR 70-93), and the median scores on the functional WB, physical WB, emotional WB, and social/family WB were 18 (13-23), 22 (17-26), 18 (16-21), and 25 (22-27), respectively. 42 patients (6%) reported a clinically deficient QOL score on the FACT-G (score ≤50 on 0-100 scale). When comparing QOL scores between those who were on active therapy versus those who were not yet treated, physical WB (p<0.0001) functional WB (p=0.00014), and total FACT-G (p=0.0013) were lower in those on active treatment. All QOL measures but emotional WB were significantly associated with OS (all p<0.04), and all but LASA spiritual WB remained significant after adjusting for IPI and NHL subtype. Associations were stronger for OS than EFS. For OS, the strongest associations were with total FACT-G (adjusted HR=0.86, 95% CI: 0.79-0.94, p=0.00062) and functional WB (adjusted HR=0.88, 95% CI: 0.83-0.93, p<0.0001). The one-question QOL LASA was also associated with OS (adjusted HR=0.92, 95% CI: 0.87-0.97, p=0.0041). The strongest association with EFS was with functional WB (adjusted HR=0.92, 95% CI: 0.88-0.97, p=0.0015). Patients with a clinically deficient QOL (baseline overall QOL ≤50) had a median OS of 59 months compared to 121 months for patients with baseline QOL >50, p=0.0002, figure 1. In a sensitivity analysis, raw QOL was modeled for OS and EFS in the subset of patients with QOL assessed prior to treatment; hazard ratios were consistent with the adjusted QOL HR in all patients. Conclusions: In this large sample of patients with aggressive lymphoma, baseline QOL is predictive of OS and EFS, even after adjustment for known factors related to survival (IPI and histological subtype). This provides evidence that patient-reported outcomes are as important as other more objective previously confirmed IPI measures. QOL should be assessed at diagnosis as a prognostic factor in patients with aggressive lymphoma. Figure 1 Association of QOL with overall survival. Figure 1. Association of QOL with overall survival. Disclosures No relevant conflicts of interest to declare.

Abstract Background:The pathological behavior of Waldenströms macroglobulinemia (WM) cells relies on aberrant B-cell receptor (BCR), and Toll-like receptor (TLR) signaling and is intricately supported by malfunctions in initiation of apoptosis. In this dynamic, a complex shift between functionally active pro-apoptotic and anti-apoptotic proteins from the Bcl-2 family occurs and bestows the malignant cells with a significant survival advantage. This defective apoptotic signaling is associated with aggressive clinical behavior, chemoresistance, and a poor prognosis in many B-cell cancers, including WM. Thus, BCR/TLR induced proliferation and abnormal apoptotic signaling due to dysregulation of Bcl-2 signaling, act in concert for the assurance of the malignant WM cells survival. Clinically, mitigation of BCR signaling with the first in class BTK inhibitor, ibrutinib, has shown promising results in WM and other B-cell cancers. However, clinical responses to the BTK inhibitor alone are less than optimal and development of ibrutinib-resistant disease is being recognized as an important and impending dilemma. We have previously shown the utility of disrupting pro-apoptotic Bcl-2 protein interactions in WM, chronic lymphocytic leukemia and multiple myeloma and that this functional interference results in re-sensitization (or heightened sensitivity) of tumor cells towards chemoimmunotherapy. As such, we examined the effects of ABT-199, a Bcl-2 specific small molecule inhibitor, in preclinical models of WM. Importantly; we conducted this investigation in proprietarily developed WM cells that have acquired resistance mechanisms towards either ibrutinib (IR WM subclones) or bortezomib (BR WM subclones). Materials:WM cell lines (BCWM.1, MWCL.1 and RPCI-WM1; WT cells) including their bortezomib resistant (BR) or ibrutinib resistant (IR) subclones were used in this study. Results: An initial comparison of Bcl-2 family members, Bcl-2, Mcl-1, BCL-xL, A1 (anti-apoptotic members), Noxa, Puma, Bim (pro-apoptotic initiators) and Bak and Bax (pro-apoptotic effectors), revealed that BR WM cells express increased levels of pro-apoptotic Bcl-2 family members, particularly Bcl-2, relative to WT cells. Similarly, A1 and Bcl-2 levels were up regulated in IR cell lines suggesting that the Bcl-2 mediated survival pathway is involved in resistance to both bortezomib and ibrutinib. Cell growth (MTS) assays using ABT-199 indicated that both BR and IR cells were equally sensitivity to Bcl-2 inhibition, with an IC50 ranging between 2 – 4mM. ABT-199 induced a dose dependent increase in MOMP with concomitant induction of apoptotic cell death, the latter confirmed by observation of PARP-1 cleavage. ABT-199 induced an intrinsic apoptotic program with the activation of caspase 9 and caspase 3 in all the cells tested. This data indicated the Bcl-2 pathway as being relevant and essential in WM cell lines even under drug resistant conditions. To evaluate the priming effect of ABT-199 on bortezomib and ibrutinib induced cell death, MTS assays were performed with these drugs in presence of IC25 concentrations of ABT-199. The addition of ABT-199 significantly reduced the IC50of both bortezomib and ibrutinib in WT, BR and IR cells. This suggested that re-sensitization of BR and IR cells towards either bortezomib or ibrutinib, respectively, was possible in presence of ABT-199. Further, combined addition of ABT-199 with bortezomib or ibrutinib showed synergistic cell death (combination index range: 0.004 – 0.6, CalcuSyn, Biosoft UK) in BR or IR WM cells, respectively. Conclusion: Dysregulation of Bcl-2 signaling is associated with the pathogenesis and promotion of drug resistance in B-cell cancers, including WM. Our report is first to highlight in WM preclinically, the antiproliferative effect of disrupting Bcl-2, through use of ABT-199. Altogether, our data suggests that therapeutic interference of Bcl-2 function with ABT-199 complements the anti-WM activity of ibrutinib or bortezomib in a synergistic manner and can in fact restore sensitivity of either drug in WM cells that are resistant to proteasome or BTK inhibitors. Focused mRNA and protein profiling analyses are currently underway to delineate the mechanisms accounting for synergy observed between concomitant Bcl-2/BTK inhibition as well Bcl-2/proteasome inhibition. Disclosures Ansell: Biothera: Research Funding. Martin:Janssen: Honoraria. Coleman:Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Millennium: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Onyx: Speakers Bureau.

Abstract To date, whole genome and exome sequencing studies of follicular lymphoma (FL) have primarily focused on identification of small site mutations that are recurrent in FL tumorigenesis or involved in tumor clonal evolution. A comprehensive genomic and transcriptomic survey of various mutation types including large structural variants (SVs) in FL cases with detailed clinical annotations and long-term follow-up has not been accomplished. To gain insight into genetic biomarkers that may predict clinical features, we performed exome and whole genome mate-pair sequencing of fresh frozen tumor and paired peripheral blood DNAs, and transcriptome sequencing of tumor RNAs, from 8 FL patients. The patients we selected were either below the median age of FL onset (n=7, median 54.5 yrs) or had a family history of lymphoma (n=1). These patients were clinically diverse, and included patients who had Grade 1 or 2 disease (n=4), classified as “indolent”; and patients with Grade 3a disease (n=2) or who subsequently had pathologic transformation (n=2), classified as “aggressive”. The coding regions of the genome (exome) were captured using Agilent SureSelect Target Capture Kit V2.0, and sequenced at 100-bp paired-end. The single nucleotide variants (SNVs) and small insertions and deletions (INDELs) were called using The Genome Analysis Toolkit (GATK), and the exon level copy number variants (CNVs) we identified using patternCNV. The whole-genome mate-pair libraries of both normal and tumor DNAs with 3kb insert sizes were sequenced paired end at 50-bp. The large SVs of CNVs, large INDELs, translocations, and inversions were identified using the SnowShoes-SV algorithm. The RNA sequencing libraries of 8 FL tumors were constructed using Illumina TruSeq protocol, and sequenced at 50-bp paired end. The RNA-Seq data were analyzed using TopHat and the fusion transcripts were identified using SnowShoes-FTD. Our analysis of SNVs and INDELs revealed mutations in previously reported genes including MLL2, CREBBP, TNFRSF14, and histone cluster genes (HIST1H2AM, HIST1H2BD). In addition, we identified novel recurrent mutations in cysteine-rich PAK1 inhibitor (CRIPAK) in 25% of the tumors. In a secondary analysis performed by Sanger sequencing or re-analysis of publically available RNA sequencing data, we identified CRIPAK mutations in 44% of FL (n=32) and 28% of DLBCL tumors (n=102). Bioinformatics analysis shows that the coding region of CRIPAK is highly enriched with the protein functional domain, post-SET, which is usually found in histone lysine methyltransferases (HMTase) genes including MLL2 and EZH2 that are known to be important in lymphomagenesis. Interestingly, CRIPAK is part of the same regulatory network consisted of previously identified lymphoma genes including MLL2, EZH2, CREBBP, and EP300, according to the shortest path algorithm by MetaCore (Philadelphia, Pennsylvania). Recurrent SVs identified in the FL tumors included the well-known IGH-BCL2 translocation, or t(14;18), in 6 out of 8 cases (75%) and the chr1q amplifications in 4 out of 8 (50%) tumors. Other non-recurrent large CNVs involving entire chromosomes or chromosome arms, as well as other inter- and intra-chromosomal structural variants were detected in individual tumors. In addition, we identified and validated 6 fusion transcripts from the transcriptome sequencing data in 3 out of 8 cases (38%). While our sample size is small, we found that SNVs and INDELs in MLL2, CREBBP, TNFRSF14, CRIPAK, and histone cluster genes, as well as t(14;18), did not distinguish indolent or aggressive tumors. However, all aggressive (4/4, 100%) and none of the indolent tumors had gains in chr1q; and the presence of RNA fusion transcripts were observed in aggressive tumors only (3/4, 75%). Additionally, we found that aggressive tumors had higher numbers of genes with point mutations (SNVs and short INDELs) (40 ± 7.6 vs. 26 ± 2.6; aggressive vs. indolent), higher numbers of genes impacted by copy number aberrations (1060 ± 263.7 vs. 233 ± 133.9), and higher numbers of large SVs (24 ± 10 vs. 6 ± 1.6). Taken together, our comprehensive analysis of 8 FL tumors reveals genetic diversity among newly diagnosed FL patients, identifies novel and recurrent mutations in CRIPAK, and finds that high tumor complexity and DNA instability may be indicators of aggressive disease. Disclosures No relevant conflicts of interest to declare.

Abstract Background: Enteropathy-associated T-cell lymphoma (EATL) is a very rare primary intestinal non-Hodgkin lymphoma (NHL) strongly associated with celiac disease. Previous studies suggest that EATL may be more common in Europe and among white population, in which celiac disease is a prevalent condition. However, comparative racial epidemiologic study of EATL in a large population is lacking and clinical studies remain limited to small series. Using two U.S. population databases, we determined the comparative incidences according to race and described the clinical features and outcome of the largest series of EATL reported to date. Methods: Incidence rates (case/1,000,000) were calculated using 2000-2010 data from the Surveillance, Epidemiology, and End Results (SEER) Program and age-adjusted to the U.S. 2000 standard population. Patient level data were obtained from the National Cancer Data Base (NCDB) Participant User File and analyzed for demographic patterns and stage distribution (1998-2011) as well as overall survival (1998-2006). SEER, a program of the U.S. National Cancer Institute, collects cancer incidence and survival data from population-based cancer registries covering approximately 28 percent of the U.S. population. NCDB, a joint program of the American College of Surgeons and the American Cancer Society, is a nationwide oncology outcomes database for more than 1,500 cancer programs in the U.S. and Puerto Rico capturing about 70% of all newly diagnosed cases of cancer in the U.S. Results: In the years 2000-2010, the overall incidence rate of EATL in the U.S. population was 0.111. Asians/Pacific Islanders had a higher incidence rate (0.236) compared to other races (whites [0.101], blacks [0.107], American Indians/Alaska natives [0.128]). The risk ratio of Asians compared to non-Asians was 2.32 (95% CI: 1.39-3.69; P =0.002). From 1998-2011, 515,026 patients were diagnosed with NHL and 337 (0.07%) had EATL. The median age was 64 years (range, 20 -90+ years) and 60% of patients were males. The stage distribution was as follows: I (26.7%), II (16.3%), III (3.3%), IV (29.1%), and unknown (24.6%). The median overall survival (OS) for the entire cohort was 5.9 months. Patients diagnosed in the more recent era (2003-2006) had a better outcome (median OS, 6.6 versus 2.6 months; Figure 1; P = 0.034). Asians/Pacific Islanders had a worse outcome compared to other races (Figure 2; P = 0.031). Multivariable analysis showed the following to be independent factors associated with inferior OS: age >60 years (HR: 1.49; 95% CI: 1.05-2.10), Asians/Pacific Islanders (HR: 2.27; 95% CI: 1.08-4.76), stage III/IV (HR: 3.03; 95%CI: 2.00-4.59), and diagnosis before 2003 (HR: 1.59; 95%CI: 1.10-2.28). Conclusions: Contrary to previous studies, we find that the highest incidence and lowest survival rates of EATL occur among Asians/Pacific Islanders, populations in which celiac disease is not considered to be prevalent. The overall survival of EATL patients has improved over time but remains poor. Figure 1 Figure 1. Figure 2 Figure 2. Disclosures No relevant conflicts of interest to declare.

Abstract Background Outcomes for patients with DLBCL have improved over the past decade, with the addition of rituximab to CHOP or CHOP-like multi-agent chemotherapy regimens improving the 3-year overall survival (OS) of patients by 10-16% compared to multi-agent chemotherapy alone (Coiffier 2002; Pfreundschuh 2010). However, patients with high-intermediate or high-risk disease have relatively poor outcomes with the standard RCHOP regimen (Ziepert 2010); in a recent prospective trial of intermediate- and high-risk DLBCL patients, complete response (CR) rate for RCHOP alone was 26% (Hainsworth 2011). Brentuximab vedotin (ADCETRIS®) is an antibody-drug conjugate comprising the antibody cAC10, specific for human CD30, covalently attached to the microtubule-disrupting agent monomethyl auristatin E (MMAE) via a protease-cleavable linker. Brentuximab vedotin has demonstrated compelling activity as a single agent in patients with relapsed or refractory DLBCL, even those with low CD30 expression (Bartlett 2013). This phase 2, randomized, open label study is designed to evaluate the antitumor activity and safety of brentuximab vedotin (1.2 or 1.8 mg/kg) when administered in combination with standard RCHOP chemotherapy (A+RCHOP) for the front-line treatment of patients with CD30-unselected high-intermediate/high-risk (standard IPI score 3–5 or age-adjusted IPI [aaIPI] score 2–3) DLBCL (ClinicalTrials.gov NCT01925612). Methods Patients were randomized to receive up to 6 cycles of either 1.2 or 1.8 mg/kg brentuximab vedotin administered IV on Day 1 of every 21-day cycle in combination with RCHOP; prednisone was administered orally on Days 1-5 of every 21-day cycle. Assessments included disease response per Cheson 2007, as evaluated by the investigator, surveillance of adverse events (AEs), physical examination findings, and laboratory testing. The primary endpoints for this study are the CR rate at the end of treatment (EOT) and the type, incidence, and severity of AEs. Key secondary endpoints include objective response rate (ORR), progression-free survival (PFS), and OS. Results At the time of the planned interim analysis, 33 patients were enrolled (17 patients, 1.2 mg/kg A+RCHOP; 16 patients, 1.8 mg/kg A+RCHOP). Median age for all patients was 66 years (range, 21 to 81). At baseline, 36% were high-risk (IPI 4-5, aaIPI 3) and 64% were high-intermediate risk (IPI 3, aaIPI 2). The majority of patients (73%) had Stage IV disease and 33% had an ECOG status of 2. At the time of interim analysis, a total of 12 patients (6 patients in each arm) had completed EOT. Across both dose levels, ORR was 92% (11/12), with 7 CRs (58%), 4 PRs (33%), and 1 PD. The patient with PD subsequently died. Patients with PR had a median reduction of baseline tumor size of 84% (range, 92% to 83%), as measured by SPD. The only patient with follow-up after EOT converted from PR to CR without subsequent therapy. Treatment-emergent AEs occurring in ≥30% of patients treated (26/33) were nausea, diarrhea, peripheral sensory neuropathy, fatigue, and decreased appetite. Grade 3 or higher events occurring in more than 2 patients were febrile neutropenia and neutropenia. Events of peripheral neuropathy occurred equally per arm (46%, 1.2 mg/kg A+RCHOP; 46% 1.8 mg/kg A+RCHOP) and were generally Grade 1 or 2 (15% and 23%, respectively); events were of similar grade across dose levels. The median time to onset of any grade of peripheral neuropathy was 6 weeks (range, 2 to 10 weeks). Five patients (19%) had dose reductions due to peripheral neuropathy and 3 patients (12%) had dose reductions due to febrile neutropenia. One patient who received 1.2 mg/kg A+RCHOP discontinued study drug due to an AE (thrombocytopenia). Conclusions At doses of 1.2 or 1.8 mg/kg, A+RCHOP exhibited manageable toxicity in the treatment of newly-diagnosed DLBCL; the incidence of peripheral neuropathy was similar to single-agent administration of brentuximab vedotin (Pro 2012, Younes 2012) and RCHOP alone (Rummel 2013, Flinn 2014). In 12 patients with response-assessable, high-intermediate and high-risk DLBCL, A+RCHOP showed encouraging antitumor activity, with an ORR of 92% and a CR rate of 58%. Disclosures Yasenchak: Seattle Genetics, Inc.: Research Funding. Off Label Use: Brentuximab vedotin is indicated in the US for treatment of patients with Hodgkin lymphoma after failure of autologous stem cell transplant or after failure of at least two prior multi-agent chemotherapy regimens in patients who are not ASCT candidates and for the treatment of patients with systemic anaplastic large cell lymphoma after failure of at least one prior multi-agent chemotherapy regimen. . Farber:Seattle Genetics, Inc.: Research Funding. Budde:Seattle Genetics, Inc.: Research Funding. Ansell:Seattle Genetics, Inc.: Research Funding. Advani:Takeda Pharmaceuticals International Co.: Research Funding; Celgene: Research Funding; Pharmacyclics: Research Funding; Jansseen Pharmaceuticals: Research Funding; Genentech: Research Funding; Seattle Genetics, Inc.: Research Funding, Travel expenses Other. Holkova:Seattle Genetics, Inc.: Research Funding. Halwani:Seattle Genetics, Inc.: Research Funding. Knapp:Takeda Pharmaceuticals International Co.: Research Funding; EMD Serono: Research Funding; Bristol Myers Squibb: Research Funding; Celgene: Research Funding; Merck: Research Funding; Heron Pharmaceuticals: Research Funding, Travel expenses, Travel expenses Other; Genentech: Research Funding, Travel expenses, Travel expenses Other; Seattle Genetics, Inc.: Research Funding; Pharmacyclics: Research Funding. Fayad:Seattle Genetics, Inc.: Consultancy, Research Funding. Kolibaba:Genentech: Research Funding; Takeda Pharmaceuticals International Co.: Research Funding; Seattle Genetics, Inc.: Research Funding. Patel-Donnelly:Seattle Genetics, Inc.: Research Funding. Seetharam:Seattle Genetics, Inc.: Research Funding. Manley:Seattle Genetics, Inc.: Employment, Equity Ownership. Bartlett:Genentech: Research Funding; ImaginAb: Research Funding; Celgene: Research Funding; MedImmune: Research Funding; Novartis: Research Funding; Pharmacyclics: Research Funding; Pfizer: Research Funding; Takeda Pharmaceuticals International Co.: Research Funding; Seattle Genetics, Inc.: Research Funding, Travel expenses Other; Janssen: Research Funding; Astra Zeneca: Research Funding.