Citations

Abstract Background: Peripheral T-cell non-Hodgkin’s lymphomas (PTCL) account for approximately 10% of all non-Hodgkin’s lymphomas in the U.S. and Europe. PTCL, unspecified (PTCL-U), as classified by the WHO, is the most common subtype. The ability of high-dose therapy (HDT) and stem cell transplantation (SCT) to improve patient outcome was evaluated in the current study. Methods: All patients with PTCL-U evaluated at our institution who had tissue specimens available for review from January, 1994 to December, 2005 were identified and both clinical characteristics and treatment course obtained from the medical record. Results: 89 patients with PTCL-U were identified, with a median follow up of 13 months (range 1 month–12 years). The median age at diagnosis was 56 years (range 24–90). The IPI was low, intermediate or high in 34%, 44% and 22% of patients, respectively. On univariate analysis, age >60 (p<.0001), ECOG performance status >1 (p<.0001), LDH greater than normal (p=.004), Ann Arbor Stage III/IV (p=.01) and the presence of B symptoms (p=.0004) were associated with a poorer overall survival, as was an intermediate or high IPI (p<.0001). In contrast, on multivariate analysis only age >60 (p=.0006) and ECOG performance status >1 (p=.007) were independently associated with poorer overall survival. Fifty-seven percent of patients were treated initially with an anthracycline-based regimen, most commonly CHOP (53%). Patients with a low (0–1), intermediate (2–3) or high (4–5) IPI experienced a 61%, 29% and 18% 5-year overall survival, respectively. Fourteen patients (16%) received HDT and autologous (n=12) or allogeneic (n=2) SCT, either at the time of a first partial or complete response (n=11) or at the time of first relapse (n=3). The median survival in those patients treated initially with an anthracycline-based regimen alone was 11 months (95% CI 0.6–1.6 years). Improvement in both 5-year overall (75% vs 24%, HR=5.6, 95% CI 2.0–23.4, p=.0004) and disease-free (60% vs 26%, HR=3.2, 95% CI 1.3–9.3, p=.008) survival was observed in patients who received HDT/SCT, as compared to patients treated with anthracycline-based therapy alone. Furthermore, improvement in both 5-year overall (80% vs 26%, HR=5.8, 95% CI 1.7–35.7, p=.002) and disease free (72% vs 26%, HR=3.8, 95% CI 1.3–15.8, p=.009) survival was observed in patients who received HDT/SCT at the time of a first partial or complete response when compared to patients who received anthracycline-based therapy. When patients who failed to achieve a first partial or complete response were excluded from the analysis, improved 5-year overall (80% vs 57%, HR=0.5, 95% CI 0.1–2.1, p=.4) and disease-free (72% vs 53%, HR=0.7, 95% CI 0.1–2.3, p=.5) survival were observed in patients who received upfront HDT/SCT, although this failed to reach statistical significance. The improved overall and disease free survival observed in patients receiving HDT/SCT, either at the time of a first response or at the time of relapse, remained significant when accounting for differences in the IPI. In conclusion, selected patients with PTCL-U may benefit from treatment with HDT/SCT following a first response to conventional anthracycline-based chemotherapy.

Abstract 44 patients with relapsed or refractory CD20+ NHL were enrolled on a phase I trial of dose-escalated 90YZ followed by high-dose BEAM and autotransplant in which the 90YZ dose was patient-specific based on dosimetry. 90YZ doses were calculated to deliver cohort-defined radiation doses (100–1700 cGy) to critical organs (liver, lung or kidney) with 3–6 patients per cohort. On D-22, rituximab (R) 250 mg/m2 was infused followed by 111In Zevalin®. Imaging was performed immediately and at 4, 24, 72 and 144 hours; dosimetry was performed on D-15. On D-14, R was followed immediately by 90YZ at the cohort-prescribed dose. On D-6 through D-1, patients received high-dose BEAM. On D0, a minimum of 2.0 × 106 CD 34+ cells/kg was infused and G-CSF 5 μg/kg SQ daily begun. The median age was 54 (range: 25–73) years. NHL histologic subtypes were as follows: 16% mantle cell, 57% diffuse aggressive, 11% low-grade and 16% transformed. 43% had recieved 3 or more chemotherapy regimens, and 70% had received R either alone or in combination with chemotherapy. The toxicity profile was similar to that associated with high-dose BEAM. The most common grade III/IV toxicities were infection, fever, stomatitis, nausea, vomiting, diarrhea. One patient experienced transient veno-occlusive disease at the 700 cGy dose level. Two dose-limiting toxicities occurred at the 1700 cGy dose level: one patient with grade 4 stomatitis died of pneumonia and sepsis on D+10, and one patient experienced septic emboli to the lung on D+13. Engraftment occurred at a median of 10 days (range: 8–18 ) to granulocytes ≥ 500/μL, and 21 days (range: 11–40 days) to platelets ≥20,000/μL. One heavily pretreated patient developed MDS on D+291 and expired of sepsis on D+483. With a median follow-up of 21 months, the three year overall and progression-free survivals are 52% and 37%, respectively. 90YZ Zevalin ® Dosing for Cohorts 5–9 (median;range) Cohort (cGy) Total Dose (mCi) mCi/kg 900(n=3) 28(27–37) 0.3(0.3–0.4) 1100(n=5) 51(29–65) 0.6(0.5–0.8) 1300(n=5) 61(39–98) 0.6(0.5–1.1) 1500(n=6) 73(51–99) 0.9(0.5–1.4) 1700(n=3) 98(82–104) 1.2(1.1–1.2) For dosimetry-based trials, 1500 cGy to the critical organ (nearly always liver) is the recommended dose. Although patient-specific doses calculated to deliver a cohort-prescribed absorbed radiation dose to the critical organ were highly variable, the two dose-limiting toxicities ocurred at nearly identical doses (1.14, 1.20 mCi/kg) when calculated according to weight. Whereas eight other patients safely received at least twice the conventional 0.4 mCi/kg dose, 0.8 mCi/kg is the recommended dose for phase II studies, if dosing is to be based on weight and not dosimetry. Outcomes are encouraging given the high-risk patient population. A phase III trial will be required to establish whether or not the addition of 90YZ to high-dose BEAM improves outcomes in NHL patients undergoing autotransplant.

Abstract Background: Patients (pts) with aggressive NHL who relapse after conventional chemotherapy or stem cell transplant have a poor prognosis. Novel agents are needed for this important subset. Tipifarnib is an orally available methylquinolone derivative that is an inhibitor of the farnesyl transferase enzyme that transfers the farnesyl group from farnesyl pyrophosphate to specific polypeptides including small GTPases of the Ras, Rho-B, and Rheb families, as well as nuclear lamins and kinetochore proteins. Tipifarnib has documented activity in acute leukemia and produces stable disease in relapsed multiple myeloma. The goal of this study was to evaluate the activity of single-agent tipifarnib in patients with relapsed aggressive NHL in the context of a phase II trial. Methods: Pts with relapsed diffuse large, follicular grade III, or mantle cell lymphoma were eligible for this study. Pts were treated with oral tipifarnib 300 mg twice daily d1–21 q 28 days until progression. Pts were restaged after 2 cycles, 6 cycles, and every 3 cycles thereafter. Tumor was sampled prior to tipifarnib and at day 8 in selected patients with accessible tumors. These paired samples were assayed for accumulation of unprocessed HDJ-2 and prelamin A, two polypeptides that require farnesylation for processing. Results: Forty-two pts were accrued between March 2004 and June 2006. Thirty-seven pts had diffuse large cell, 1 follicular grade III, and 4 had mantle cell. Of the 38 patients evaluable for response, 7 (18%) had a partial response and 8 (21%) had stable disease. The 7 responders all had diffuse large cell histology. Median progression-free survival (PFS) for all pts was 2 months (range, 0–25+). The PFS of the 7 responders was noteworthy at 4.2, 4.9+, 6.7, 9.6, 14.9+, 21.6+, and 25.1+ months, respectively. The primary toxicity was myelosuppression and 33% of pts required dose reductions. The median dose received in all pts was 300 mg twice daily (mean 275, range, 100–400). The median dose received by the 7 responders was 200 mg twice daily (range, 100–400). The dose of 300 mg twice daily resulted in accumulation of unfarnesylated forms of one or both markers in all pts studied to date. Conclusion: Oral tipifarnib has antitumor activity as a single agent with an excellent toxicity profile in pts with relapsed/refractory aggressive lymphoma. When given in this dose and schedule, tipifarnib is well-tolerated and can be taken for months without cumulative toxicity. This drug warrants further investigation in combination with conventional chemotherapy and other novel agents for the treatment of this important subset of patients.

Abstract Abstract 1222 Poster Board I-244 Background Survival for patients with primary CNS lymphoma (PCNSL), in general, is poor with patients requiring frequent chemotherapy treatments or receiving whole-brain radiation therapy, which can potentially result in significant neurologic decline and dementia. Because of the improved survival of high risk patients with aggressive lymphoma undergoing autologous stem cell transplant (ASCT), we began ASCT for patients with PCNSL in first or later remission with chemotherapy sensitive disease. We now update on outcomes of patients who have had at least 100 day follow up post ASCT. Baseline characteristics Between June, 2000 and January, 2009, 22 patients underwent ASCT for PCNSL. Median age at transplant was 50 years old (range 26-67). Median number of prior treatments 1 (range 1-3). Median time from diagnosis to transplant was 7.2 months (range 2.9 to 75.8). Median International Extranodal Working Study Group Prognostic Score: 2 (range 0-3). Disease status at transplant: First CR 10 patients, later CR or PR 12 patients. Results Twenty-two patients underwent ASCT for PCNSL and have a minimum of 100 days follow-up. All patients received BEAM conditioning. Median follow up post-transplant was 30 months (range 3-107 months). Eight patients have relapsed at a median of 217 days (range 40-1349). Of the patients who relapsed, four have died of disease progression and the remaining four are alive after additional therapy. Median overall survival from diagnosis or transplant has not been reached. Median progression free survival from transplant was 70 months. Conclusions Although limited by patient selection and retrospective biases, this review suggests that ASCT for PCNSL demonstrates improved overall survival when compared to historical controls with similar PCNSL Prognostic Scores (2 year survival for patients from diagnosis with PS 2-3 was 48% in a prior published study). ASCT in first remission in patients with PCNSL appears promising and may limit the need for additional therapy which can be myelosuppressive or result in neurologic decline secondary to radiation therapy in patients who are appropriate candidates. Disclosures No relevant conflicts of interest to declare.

Abstract Abstract 1540 Background: Diffuse Large B-cell Lymphoma (DLBCL) is the most common lymphoma in the western world. Outcomes have improved with the standard initial therapy of rituximab and anthracyline based chemotherapy (immunochemotherapy). However, 20–40% of patients will either fail to achieve remission or relapse following initial immunochemotherapy. Most relapses occur early, and long-term outcome of relapsed/refractory patients is generally poor despite salvage regimens and stem cell transplant. Traditionally, studies for DLBCL have been evaluated using progression-free and/or overall survival. However, the event rate in DLBCL slows significantly approximately 12–18 months after diagnosis, and late events are often due to competing (non-DLBCL related) risks, especially in older patients. Here we examine outcome of DLBCL patients based on their event status at 12 months. Methods: Newly diagnosed DLBCL patients were prospectively enrolled in the University of Iowa/Mayo Clinic Lymphoma SPORE Molecular Epidemiology Resource (MER). Clinical data were abstracted from medical records using a standard protocol. Patients were actively followed for events (progression, re-treatment, or death due to any cause) and overall survival (OS). Event-free status at 12 months after diagnosis (EFS12) was assessed as a dichotomous variable. Cause of death was determined by medical record and death certificate review using prospectively determined definitions. Expected survival was based on age and sex matched survival using the Minnesota population death rates. Confirmation cohorts were from a Lyon, France hospital based registry and NCCTG clinical trial N0489. Results: 680 patients with newly diagnosed DLBCL and treated with rituximab + anthracycline based chemotherapy were enrolled in the MER from 2002 to 2009. The median age was 62 years (range 18–92). 53% were male. At a median follow-up of 59 months (range 8–116), 266 patients (39%) had an event and 188 patients (28%) died. 162 patients (24%) had an event in the first 12 months after diagnosis, comprising 60% of all events. Patients with an event in the first 12 months had poor survival with death almost exclusively due to disease (Figures 1a, 2a). In contrast, patients who were event-free at 12 months had comparable survival to the age and sex matched general population (Figure 2b) and were more likely to die of other causes than DLBCL (Figure 1b). Overall survival rates by EFS12 status were validated in patients from a French hospital-based registry (N=265) and the NCCTG N0489 clinical trial (N=87) with additional replication studies underway. Conclusions: DLBCL patients who are event-free at 12 months after diagnosis have an excellent prognosis with an overall survival similar to that of an age- and sex- matched general population and are more likely to die of other causes than DLBCL. This finding has implications for clinical management, new clinical trials, and follow-up testing in this patient population. In contrast, patients with an event within the first 12 months after diagnosis have a poor prognosis with almost all deaths secondary to DLBCL. EFS status at 12 months identifies patients with poor outcomes due to disease. This can be utilized as an endpoint in biologic studies and clinical trials to address early treatment failures. EFS status at 12 months should be incorporated into prognostic models to identify high risk patients in newly diagnosed DLBCL. Disclosures: No relevant conflicts of interest to declare.

Abstract Background: Absolute lymphocyte count (ALC) recovery is an independent prognostic factor for survival for different hematological malignancies treated with autologous stem cell transplantation. Recently, we reported superior overall survival (OS) in patients with follicular lymphomas that presented with a higher ALC (ALC ≥ 1 x 109/L) at diagnosis. The role of ALC at diagnosis on survival in T cell lymphomas is not known. Methods: All patients evaluated at the Mayo Clinic for T cell lymphomas from October 1984 until April 2005 were analyzed in the study. The primary objective of the study was to assess the role of ALC at diagnosis and survival in T cell lymphomas. ALC at diagnosis was obtained from the standard complete blood cell count (CBC). Results: 223 patients with T cell lymphomas were included in the study. The histology included: peripheral T-cell lymphoma-unspecified (40%), anaplastic large cell (13%), angioimmunoblastic (10%), angiocentric (4%), intestinal T-cell (2%), and other (31%). The median follow-up was 18.6 months (range: 1 month – 229 months [19 years]). The sample population included 60% male and 40% females with a median age of 60 years (15–90 years). The median ALC at diagnosis was 1.2 x 109/L (range: 0.04–6.7 x 109/L). ALC as a continuous variable was identified as predictor for OS in the univariate analysis (HR= 0.690, 95%CI: 0.542–0.862, p < 0.0006). ALC ≥ 1 x 109/L was selected as the dichotomized value because it yielded the maximum difference in survival by c2 analysis looking at different cut-point from 0.6 to 1.7 x 109/L that were included between the 25% and 75% quartiles. Univariately, ALC ≥ 1 x 109/L was also identified as a predictor for OS (HR = 0.682, 95%CL= 0.578–0.804, p < 0.0001). Patients (N = 122) with an ALC ≥ 1 x 109/L experienced superior survival compared to patients (N = 101) with an ALC < 1 x 109/L [median OS: 76.3 vs 10.6 months, respectively; and 5 years OS estimates of 53% vs 23%, respectively, p < 0.0001]. When ALC ≥ 1 x 109/L was compared to the international prognostic index (IPI), ALC ≥ 1 x 109/L remained an independent predictor for survival in the multivariate analysis (HR = 0.779, 95%CL: 0.655–0.925, p < 0.004). Conclusion: This study demonstrates ALC as an independent predictor for OS in T cell lymphomas, suggesting that the host immune system affects survival in this group of patients.

Abstract Abstract 1527 Interim Positron-Emission Tomography (PET-scan), as a functional imaging test for tumor activity, has been shown to be a predictor for progression-free survival (PFS) and time to progression (TTP) in classical Hodgkin lymphoma (HL). The peripheral blood absolute lymphocyte/monocyte ratio (ALC/AMC) at diagnosis, as a surrogate marker of host immunity (i.e., ALC) and tumor microenvironment (i.e., AMC), has been recently reported [Porrata et al, Hematologica 2012; 97(2): 262–9] and confirmed [Koh et al, Oncologist 2012; 17(6): 871–80] to be also a predictor for PFS and TTP in classical HL. Therefore, we evaluated the combination of ALC/AMC ratio at diagnosis and the interim PET-scan to further stratify the clinical outcomes of PFS and TTP in patients with classical HL. To participate in the studies, patients were required to be diagnosed, treated, and followed at Mayo Clinic, Rochester, Minnesota. The treatment consisted of adriamycin, bleomycin, vinblastine, and dacarbazine (ABVD) with or without radiation therapy. Patients were required to have an interim PET-scan performed. An ALC/AMC ratio ≥1.1 cut-off was used in the study based on our previous publication [Porrata et al, Hematologica 2012; 97(2): 262–9]. From 2000 until 2008, 111 classical HL patients qualified for the study. The cohort included 54% males and 46% females. The median age at diagnosis was 37 years (range: 18–83 years). The median follow-up was 2.8 years (range: 0.3–10.4 years). Patients with a negative interim PET-scan (N=98) presented with a higher ALC/AMC ratio at diagnosis (median of 2.32, range: 0.26–37.5) compared with patients with a positive interim PET-scan (N = 13) (median of 0.9, range: 0.29–3.10), p < 0.004. By univariate analysis, the ALC/AMC ratio at diagnosis and the interim PET-scan were predictors for PFS [ ALC/AMC ratio, R =0.13, 95% CI (0.05–0.35), p < 0.0002; and interim PET-scan, HR = 0.13, 95% CI (0.05–0.37), p < 0.0003] and TTP [ALC/AMC ratio, R =0.07, 95% CI (0.02–0.24), p < 0.0001; and interim PET-scan, HR = 0.05, 95% CI (0.01–0.18), p < 0.0003]. By multivariate analysis, ALC/AMC ratio at diagnosis and the interim PET-scan were independent predictors for PFS [ ALC/AMC ratio, R =0.13, 95% CI (0.07–0.63), p < 0.006; and interim PET-scan, HR = 0.11, 95%CI (0.02–0.47), p < 0.003] and TTP [ALC/AMC ratio, R =0.11, 95% CI (0.02–0.71), p < 0.02; and interim PET-scan, HR = 0.10, 95% CI (0.02–0.46), p < 0.003] when compared to the International Prognostic Score, limited versus advanced stage, and radiation. Patients were stratified into four groups: group 1 included patients with a negative interim PET-scan and ALC/AMC ratio at diagnosis ≥1.1 (N = 88); group 2 included positive interim PET-scan and ALC/AMC ratio at diagnosis ≥1.1 (N = 5); group 3 included negative PET-scan and ALC/AMC ratio at diagnosis < 1.1 (N = 10); and group 4 included positive PET-scan and ALC/AMC ratio at diagnosis <1.1 (N = 8). The three year PFS rates for each group were for goup1 95% (Events = 6); group 2 40% (Events = 3); group 3 56% (Events = 4); and group 4 50% (events = 4), p < 0.0001. The three year TTP rates for each group were: for group1 was 100% (Events = 0); for group 2 of 40% (Events = 3); for group 3 of 65% (Events = 3); and group 4 of 50% (events = 4), p < 0.0001. In conclusion, the ALC/AMC ratio at diagnosis is independent of the interim PET-scan to predict PFS and TTP in classical HL. Further studies are warranted to confirm our findings and to assess if the combination of the ALC/AMC ratio at diagnosis and interim PET can be use for planning of risk-adapted treatment. Disclosures: Ansell: Seattle Genetics, Inc.: Research Funding.

Abstract Background: CLL patients (pts) treated with novel targeted therapies continue to experience disease progression. Approximately 7-15% of relapsed CLL treated with ibrutinib or venetoclax developed Richter's syndrome (RS), an aggressive high grade lymphoma transformation. Standard chemotherapy has limited efficacy in RS. We hypothesized that checkpoint blockade would re-establish anti-tumor immune response in progressive CLL/RS and here we aim to update the clinical data and correlative analysis of MC1485: a phase 2 study of PD-1 blocking antibody pembrolizumab in relapsed/refractory CLL and RS. Methods: Relapsed/refractory CLL including RS enrolled in the CLL arm of MC1485 trial was reported here. The primary end point of this study is overall response rate (ORR). Pts with prior allogeneic stem cell transplant were excluded. Pembrolizumab 200 mg was administered intravenously every 3 weeks. NCI CTCAE v4.0 and IWCLL 2008 criteria were used for non-hematological adverse events (AE) and for CLL grade hematological AE. Tumor expression of PD-1 and PD-L1 were assessed with standard immunohistochemical (IHC) staining. Percentage expressions of individual antigens were analyzed with whole-slide scanning followed by image analysis with Image-Pro software (Media Cybernetics). Fluorescence in situ hybridization (FISH) was performed on available CLL/RS tissue sections to assess copy number of chromosome 9p region that contains PD-L1 and PD-L2. Results: 25 pts including 16 CLL and 9 RS (biopsy-proven large cell lymphoma) were enrolled in CLL arm. The median age was 69 years (46-81). Twelve (48%) pts had del(17p) or monosomy 17 or TP53 mutation. The median number of prior therapies was 4 (1-10). 96%, 72% or 48% of pts had received alkylator and anti-CD20 antibody, purine analog or anthracycline. Fifteen (60%) pts had prior ibrutinib and 12 (48%) progressed clinically while receiving ibrutinib, including 6 who progressed to RS and 6 who developed progressive CLL. The median number of pembrolizumab doses that pts received was 3 (1 to 21), administered over a median treatment duration of 11 weeks (1 to 56). Drug-related AE occurred in 21 pts (88%) with the most common ones being neutropenia in 9 (37%), cough in 7 (29%) and dyspnea in 6 (25%) pts. Drug-related grade 3 or above AE occurred in 9 (38%) pts with most common ones being thrombocytopenia (5, 21%), dyspnea (2, 8%), and fatigue (2, 8%). The most common immune-related AE was liver enzyme elevation (12%, 8% G3) and was reversible with therapy interruption or steroid therapy. Based on investigator assessment using the Revised Response Criteria for Lymphomas and IWCLL 2008 criteria, one RS pt had complete response (CR, 4%), 3 RS had partial responses (PR, 12%). Among 9 RS pts, 1 CR (11%), 3 PR (33%), 3 SD (33%) and 2 PD (22%) were observed. Thus the ORR in RS was 44%. No CLL pts achieved a CR/PR, 3 had SD and 9 had progressive disease (PD). The ORR of all pts was 16%. Of the 4 RS who had CR/PR, responses occurred early after 2 cycles of therapy and median duration of therapy for CR/PR pts was 8.3 months with data cut-off by June 30th 2016 (Figure 1A). The causes for therapy discontinuation in RS were PD (3, 33%), alternate therapy (2, 22%), and thrombocytopenia due to increased marrow CLL (1, 11%). Increased marrow CLL was observed in 2 RS pts with PR to RS phase of disease assessed by PET, thus the protocol was amended to allow addition of idelalisib/ibrutinib to control the underlying marrow CLL. For RS pts who had a CR/PR or SD, variable nodal responses were observed (Figure 1B). In particular, 6 RS who had prior ibrutinib experienced CR or PR or SD with nodal responses. After a median follow-up of 10.2 (1.9 to 16.1) months, the median overall survival (OS) for all pts was 10.7 months (95% confidence interval [CI], 5.4 to not reached). The 6 month OS rate for RS and CLL pts were 73% and 59%, respectively. Biomarker assessment using IHC analysis on 10 pts with available tumor/nodal tissues (6 RS and 4 CLL) showed an increased expression of PD-L1 (p = 0.02) and a trend for an increased expression of PD-1 (p = 0.1) in the group of pts with CR/ PR versus pts in the group with no clinical response. One out of 10 tested showed polysomic for chromosome 9p. Conclusion: Pembrolizumab had an acceptable safety profile in CLL and RS patients. We confirmed that pembrolizumab has substantial therapeutic activity in RS. Single-agent pembrolizumab does not appear to have clear activity in CLL. Disclosures Ding: Merck: Research Funding. Parikh:Pharmacyclics: Honoraria, Research Funding. Shanafelt:GlaxoSmithKline: Research Funding; Genentech: Research Funding; Janssen: Research Funding; Pharmacyclics: Research Funding; Celgene: Research Funding; Cephalon: Research Funding; Hospira: Research Funding.

Abstract Abstract Our group recently reported a Phase III clinical trial (Porrata et al. Biology of Blood and Marrow Transplantation 2016; 22: 1017-1023) demonstrating that the infusion of the autograft-absolute lymphocyte count (A-ALC) and autograft natural killer cells (A-NKC) are survival prognostic factors in non-Hodgkin lymphoma (NHL) patients treated with autologous peripheral blood hematopoietic stem cell transplantation (APBHSCT). A limitation of our Phase III clinical trial was the short-term follow-up of just two years. Therefore, we evaluated longer follow-up and assessed the role of the infused A-ALC, infused A-NKC, and peripheral blood absolute natural killer cell count (ANKC) recovery on survival post-APBHSCT. Of the 122 patients that participated in the Phase III trial, 111 patients were able to complete APBHSCT and included in the current study. With a median follow-up of 57.2 months (range: 2.1-84.6 months), superior overall survival (OS) and progression-free survival (PFS) was observed in patients infused with an A-ALC ≥ 0.5 x 109 lymphocytes/kg [OS: HR = 0.429, 95%CI, 0.128-0.828, p < 0.01; and PFS: HR = 0.456, 95% CI, 0.177-0.863, p < 0.01] and an A-NKC ≥ 0.09 x 109 cells/kg [OS: HR = 1.58e-3, 95% CI, 1.046e-6-0.179, p < 0.003; and PFS: HR= 1.58e-3, 95% CI, 7.81e-7-0.064, p < 0.003]. Furthermore, patients that maintained an ANKC ≥ 250 cells/µl at 3 months, 6 months, 9 months and 12 months post-APBHSCT also experienced superior OS (Figure 1A) and PFS (Figure 1B)[OS and PFS times in months were evaluated from infusion date of stem cells]. In the multivariate analysis a sustained ANKC ≥ 250 cells/µl was an independent predictor for OS (HR = 0.013, 95% CI, 0.001-0.063, p < 0.0001) and PFS (HR = 0.014, 95% CI, 0.001-0.067, p < 0.0001). This study is an extension of our Phase III clinical trial showing that sustained innate immunity by measuring the ANKC correlated with superior clinical outcomes; thus providing a platform to develop innate immunity immunotherapeutic strategists directing to improve clinical outcomes post-APBHSCT in NHL patients. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

Abstract Abstract 1575 We recently demonstrated in a phase II study that the anti-CD22 monoclonal antibody epratuzumab added to RCHOP improved DLBCL survival parameters. Despite these advances, 30–40% of DLBCL patients still relapse and die of disease. Recent advances have led to the identification of a variety of intracellular oncogenic pathways as potential targets for lymphoma therapy. Specifically, many studies have found that activation of the Signal transducer and activator of transcription 3 (STAT3) pathway promotes tumor cell survival in various types of cancers. STAT3 is a transcription factor and exerts its anti-apoptototic effect through several downstream targets such as MYC. MYC protein can be expressed in lymphoma cells with or without the presence of MYC translocation. The frequency of phosphorylated STAT3 (pSTAT3) and MYC expression and their prognostic relevance are unknown within diffuse large B-cell lymphoma (DLBCL), germinal center B-cell (GCB) and non-GCB subtypes. This study studied the tumor cell expression of pSTAT3 and MYC by IHC paired with serum cytokine levels in a DLBCL patient population uniformly treated on N0489. DLBCL tumor samples (n=38) were stained for detection of nuclear pSTAT3 expression. Using a threshold of ≥30% of tumor nuclei staining positive, 35 % (14/40) of tumors were pSTAT3+. An additional 17% (7/40) had between 10–30% pSTAT3+ cells. Non-malignant tonsil tissues (n=10) were positive for tSTAT3 in all cases but all but one case were pSTAT3 negative. Twenty-four of the same DLBCL tumors used for pSTAT3 expression were stained for MYC and 50% (12/24) were MYC positive (all nuclear) as defined by the criteria of ≥30% of cells staining positive. In cases (n=23) where both MYC and pSTAT3 IHC were performed, a positive pSTAT3 was more likely to have MYC expression whereas a positive MYC stain did not inform pSTAT3. By using a break apart probe for the MYC gene, MYC translocations in the major breakpoint regions were found in 10% (3/29) of cases. When MYC FISH was correlated with MYC IHC in the 24 DLBCL cases that had both techniques performed, all 3 MYC translocation cases were GCB by IHC, two were strongly positive for MYC by IHC, and 1 was negative. Among the 21 MYC FISH negative cases, 10 were MYC positive by IHC. These data suggest that MYC expression in lymphoma is not only controlled by genetic events such as translocations but also by other signaling pathways such as STAT3. pSTAT3 expression was correlated with an elevated serum LDH (p=0.0007). Neither MYC or pSTAT3 tumor expression correlated with other clinical or pathological features. Survival analysis revealed a trend toward shorter EFS for DLBCL patients whose tumors expressed MYC protein by IHC (p=0.2) or had a MYC translocation (p=0.09) by FISH; pSTAT3 expression status did not predict EFS (p=0.9). Within the GCB group 10 cases were MYC negative (10/17; 59%) and 7 cases were MYC positive (7/17; 41%). Among the non-GCB group 83% (5/6) were MYC positive. These data clearly suggest a trend of higher MYC positivity in the non-GCB DLBCL group (p=0.07). MYC positive cases had a clear trend of inferior EFS in both GCB (p=0.2) and in non-GCB (p=0.5) groups. The distribution of pSTAT3 (n=38) expression was also evaluated in the GCB (n=26) and non-GCB (n=12) DLBCL. In the GCB group 27% (7/26) were pSTAT3 positive compared to 58% (7/12) in the non-GCB group. Thus, there was a clear trend toward higher pSTAT3 positivity in non-GCB DLBCL tumors (p=0.06); however, pSTAT3 status did not correlate with EFS in either GCB or non-GCB DLBCL patients. In the present study we correlated pretreatment serum cytokines levels of these patients with pSTAT3 and MYC tumor cell expression. Out of the 30 cytokines tested, the only pre-treatment cytokines that were significantly correlated with pSTAT3 expression were IL-10 (p=0.05), G-CSF (p=0.03) and TNFa (p=0.04); none were correlated with MYC expression. Overall, our data provide evidence that over-expression of pSTAT3 and MYC is common in DLBCL. These biomarkers have potential as prognostic factors in the case of MYC and as a tool for selecting therapy for pSTAT3. MYC may be especially useful to further identify an adverse group of DLBCL patients within the otherwise favorable GCB tumor group. The availability of JAK/STAT and STAT-specific inhibitors provides the rationale to incorporate pSTAT3 staining in tumors from patients who are participating in these trials to learn if this biomarker can predict response Disclosures: No relevant conflicts of interest to declare.