Academic literature on the topic 'B 20.5 UL 2008 F486'

e19561 Background: The clinicopathological spectrum of HIV-associated lymphomas in developing countries has not been clearly defined. Thus, this study is aimed to describe these features in cases from a Peruvian population. Methods: This is a retrospective review of the clinical records of patients with diagnosis of HIV in our institution from March 1997 to March 2008. We reviewed 2502 clinical records. The statistical method was descriptive and survival was calculated using the Kaplan-Meier method. Results: Forty-eight patients with HIV-associated lymphoma were identified. Male:female ratio was 15:1. Median age was 42 years (range 27 to 70). 32 patients (67%) had clinical stage III-IV, B symptoms 35 (73%), the International Prognostic Index was low-risk 20 patients (42%), low-intermediate risk 15 patients (31%), high-intermediate risk 10 patients (21%) and high-risk 3 patients (6%). CD4 count lower than 100 cells/uL was 11 patients (23%). The CD4 count median was 184 cells/uL. The nodal localization in 27 patients (56%) was lightly higher. Forty-four cases (92%) were diagnosed with non-Hodgkin lymphoma (NHL) and 4 cases (8%) with Hodgkin lymphoma (HL). From the 44 NHL cases, 40 cases (91%) were of B-cell origin; 23 cases (57.5%) had diffuse large B-cell, 9 cases (22.5%) had Burkitt, 3 cases (7.5%) had plasmablastic, 2 cases (5%) had primary CNS, 2 cases (5%) had MALT and 1 case (2.5%) had primary effusion lymphoma. The remaining 4 cases (9%) were of T-cell origin; 3 cases (75%) had peripheral T-cell lymphoma NOS and 1 case (25%) was ALK-negative anaplastic large cell lymphoma. Only 16 patients (33%) were receiving HAART previously the diagnosis of NHL and 33 patients (68%) received any oncology treatment. Conclusions: This entity is aggressive and frequently has extranodal involvement. Also a high proportion of T-cells lymphomas are found. These findings are in concordance with one prior report of another general hospital from Peru. No significant financial relationships to disclose.

Abstract Abstract 1588 Background: EBV-positive diffuse large B-cell lymphoma (EBV+ DLBCL) of the elderly is a provisional entity included in the 2008 WHO Classification of Lymphomas. Diagnostic criteria include age >50 years, DLBCL morphology and EBV expression in lymphomatous cells. However, these criteria are evolving as several patients are <50 years and a specific cut-off for the percentage of EBV expression has not been defined. The goal of this retrospective study is to evaluate clinical and pathological characteristics of EBV+ DLBCL from Peruvian patients. Methods: Between January 2002 and January 2012, all patients meeting criteria for EBV+ DLBCL were included in the analysis. Patients with evidence of immunosuppression were excluded. All cases re positive for the presence of EBV-encoded RNA (EBER) by in situ hybridization, and CD20 and/or PAX-5 expression by immuno-histochemistry. Clinical data were reviewed retrospectively and patient's biopsies were analyzed for the expression of BCL6, CD10, CD30 and MUM-1/IRF4 using a tissue microarray (TMA) technique. The overall survival (OS) curves were calculated using the Kaplan-Meier method, and compared using the log-rank test. Results: A total of 43 EBV+ DLBCL patients are included in this study. The median age was 73 years (range 25–95 years). Four patients (9% ) were <50 years. The male:female ratio was 2.2:1. B symptoms occurred in 59%, ECOG >21 in 60%, advanced stage (III/IV) in 58%, elevated LDH levels in 44%, and lymphocyte count <1000/uL in 35%. The International Prognostic Index (IPI) score was 0–2 in 39% and 3–5 in 61% of the patients. Extranodal disease occurred in 20 patients (46%): stomach (n=3), tonsil (n=3), pleura (n=2), palate (n=2), cecum (n=2), bone marrow (n=2), ileum (n=1), bone (n=1), skin (n=1), lung (n=1), meninges (n=1), breast (n=1) and peritoneum (n=1). Three patients had central nervous system involvement (7%), one at presentation and two at relapse. Based on the Hans classification, 76% had non-germinal center profile. Ki67 expression was >80% in 53% of the patients. Eleven evaluated patients had a c-myc-negative status. Chemotherapy was received in 75% of the cases due to poor performance status. The overall response rate with conventional chemotherapy was 46%, with complete response in 39%, partial response in 7%, and no response in 54%. The median survival was 7.5 months. The Oyama score was: 0 factors (13%), 1 factor (47%), and 2 factors (40%) with median OS of 41, 11 and 1.5 months respectively (p=0.07). A lymphocyte count <1000/uL was a prognostic factor for OS (p=0.001). Conclusions: Based on our study, which is the largest cohort in Latin-America, EBV+ DLBCL is an aggressive entity with frequent extranodal disease and poor response to conventional chemotherapy. The overall survival remains poor. Lymphopenia, as defined as lymphocyte count <1000/uL, appears as a prognostic factor for OS. Disclosures: No relevant conflicts of interest to declare.

Spred1, a member of the Sprouty family of proteins and a negative regulator of RAS-MAPK signaling, is highly expressed in normal hematopoietic stem cells (HSCs) where it negatively regulates self-renewal activity. Lack of Spred1 function has been associated with aberrant hematopoiesis (Tadokoro, 2018). Spred1 knocked-out (KO) mice fed with high-fat diet develop a myeloproliferative phenotype (Tadokoro, 2018), and lower SPRED1 expression in acute myeloid leukemia associates with a poor outcome (Li, 2015; Olsson, 2014; Pasmant, 2015), suggesting a potential role of this gene as a tumor suppressor in myeloid malignancies. In CML, however, the role of Spred1 has not been fully dissected. Thus, we generated Spred1 KO CML (i.e., Spred1-/-SCLtTA/BCR-ABL) mice by crossing Spred1 KO (a gift from Dr. Yoshimura, Japan) with inducible SCLtTA/BCR-ABL CML mice. Spred1 KO mice showed increased cell cycling of BM long-term HSCs (LTHSCs; Lin-Sca-1+c-kit+Flt3-CD150+CD48-; G0: 62% vs 76%), and increased white blood cell (WBC) counts [14 vs 5.9 k/ul at 12 weeks (w) old, n=15 per group, p<0.0001], as compared to wt mice. Upon B/A induction by tetracycline withdrawal, Spred1-/-SCLtTA/BCR-ABL mice had higher WBC (102.5 vs 12 k/ul at 4 w, n=15 per group, p<0.0001), more pronounced splenomegaly (spleen weight: 0.28g vs 0.19g, n=4 per group, p=0.06) and a significantly shorter survival (median: 39 vs 83 days, n=23 per group, p<0.0001) than Spred1 wt CML mice. In Spred1-/-SCLtTA/BCR-ABL mice, we observed a more rapid expansion of circulating mature myeloid cells (CD11b+Gr-1+ cells: 63% vs 25%, n=8 per group, p<0.01) and a deeper decrease of BM LTHSCs (1,385 vs 2,164 per femur, n=5 per group, p<0.01) and increase of spleen LTHSCs (27330 vs 18546, n=5 per group, p<0.01) at 4 w after B/A induction compared with Spred1 wt CML mice. Further, we found a higher fraction of Spred-/-SCLtTA/BCR-ABL mice (33% vs 10%) developed lymph node enlargement, with infiltration with pro-B lymphoblastic cells (B220+CD43+CD19+IgM−) compared with Spred1 wt CML mice. Altogether these features suggested that Spred1 insufficiency accelerates CML development and evolution to more aggressive phases of the disease. Since upregulation of Spred1 reportedly disrupts vascular integrity (Fish, 2008; Wang 2008), a finding that we have also confirmed in the BM niche, in order to evaluate separately the leukemogenic effect of Spred1 expression on different compartments of the BM niche, we generated the following conditional Spred1 KO strains: Spred1flox(f)/fMxl-cre+ (Spred1 KO in HSCs, hereafter called Spred1HSCΔ/Δ), Spred1f/fTie2-cre+ [Spred1 KO in endothelial cells (ECs), hereafter called Spred1ECΔ/Δ], Spred1HSCΔ/ΔSCLtTA/BCR-ABL and Spred1ECΔ/ΔSCLtTA/BCR-ABL by crossing SCLtTA/BCR-ABL with the above Spred1 KO mice. LTHSCs from Spred1HSCΔ/ΔSCLtTA/BCR-ABL mice showed an increase in cell cycling, RAS/MAPK/ERK activity and Bcl-2 levels, and higher engraftment in recipient mice (blood: 9.7% vs 26.5% at 6w, 14.8% vs 42% at 8w, 14.7% vs 48% at 12w, n=10 per group, p<0.01), compared to Spred1 wt CML LTHSCs. Spred1HSCΔ/ΔSCLtTA/BCR-ABL mice (n=15) showed enhanced leukemia progression (WBC: 19 vs 12 k/ul, p=0.004; CD11b+Gr-1+ in blood: 36% vs 25%, p=0.04 at 4 w after B/A induction) and a significantly shorter survival (median: 49.5 vs 83 days, p=0.01) compared to Spred1 wt CML mice (n=20). However, the disease in these mice appeared to be overall less aggressive than global Spred1 KO CML (i.e., Spred1-/-SCLtTA/BCR-ABL) mice (WBC: 19 vs 102 k/ul; CD11b+Gr-1+ in blood: 36 vs 63%; Survival: 49.5 vs 39 days), suggesting that Spred1 depletion in other non-hematopoietic cell compartments may also be important for leukemogenesis. In fact, Spred1ECΔ/ΔSCLtTA/BCR-ABL mice (n=8) showed enhanced leukemia progression (WBC: 26 vs 9.8 k/ul at 4 w after B/A induction, p=0.02), a trend for a reduced survival (median: 56 vs 83 days, p=0.09), and increased arteriolar vascularization, compared to Spred1 wt CML mice (n=20). Mechanistic studies on how endothelial Spred1 insufficiency co-participates in leukemogenesis are ongoing. Altogether our results support a role of Spred1 insufficiency in distinct BM niche compartments to produce a more aggressive CML phenotype, likely through different, but complementary mechanisms. Spred1 may therefore emerge as a novel target for advanced CML. Disclosures No relevant conflicts of interest to declare.

Abstract Abstract 2919 Poster Board II-895 Background: Flow cytometry (FCM) assessment of cerebrospinal fluid (CSF) has recently been known to increase the rate of positivity of occult leptomeningeal disease (LD) in comparison to conventional cytologic examination (CC). However it's still unknown its prognostic value. Patients and methods: The aim of this study was to compare CC vs FCM in a large cohort of patients with newly diagnosed aggressive NHL at high risk for LD (diffuse large B-cell lymphoma (DLBCL) IPI 2-3 and elevated LDH with at least two extranodal sites or with bone marrow, testis, paranasal sinuses, orbit or paravertebral involvement; Burkitt lymphoma (BL); blastoid variant of mantle cell lymphoma (B-MCL); B-cell precursor lymphoblastic lymphoma (B-LL); HIV+ aggressive lymphoma patients). All patients were required to have no evidence or signs of neurological disease. All patients received intrathecal standard prophylactic therapy with 12 mg of methothrexate except for BL that were given prophylaxis with 50 mg of liposomial aracytin for a total of 4 doses. CFS samples were analysed both with CC and FCM. The incidence of positive test for occult LD with FCM and CC was compared using the McNemar test for paired data. Results: Between August 2004 and June 2008, a total of 159 consecutive patients were enrolled in 11 Italian centres and underwent evaluation of CSF. Out of these, 128 patients (80%) were considered at high risk of occult LD. Clinical characteristics were: median age 53 years (IQR:43-62); DLBCL 96 patients (75%); BL 21 pts (16%); B-MCL 6 pts (5%); B-LL 5 pts (4%); 26 pts (20%) were HIV positive. FCM was able to detect a clonal population in 17 out of 128 patients (13%) whereas CC detected abnormal cells only among 7 pts (5%)(p= 0.0002). Therefore, 10 patients (8%) were discordant: FCM+/CC-. Among the 128 patients, there was no association between the CFS total protein, glucose level and the presence of positive analysis of FCM, whereas the difference between the number of WBC cells in CSF was significantly higher in patients with positive versus negative FCM with a median value of 12 cells/ul (IQR: 3.5;40) versus 1.0 cells/ul (IQR: 0.0;3.0) (p=0.0120). Univariate and multivariate analyses, using logistic models, showed that abnormal LDH (OR 3.98, 95%CI: 1-15.92)(p=0.05) and number of WBC cells in CSF ≥5 (OR 4.57, 95%CI:1.37-15.33)(p=0.014) were the only predictive factors of a positive test performed by FCM. From date of diagnosis, overall median follow up of survivors was 14 months (IQR:8-22). We observed 39 (30%) systemic progressions, 6 (5%) CNS progressions (in 5 cases an isolated CNS progression whereas 1 pts experienced a CNS along with systemic progression). Thirty-two (25%) patients died and causes of deaths were as follows: 27 progressive disease, 1 infection, 1 treatment related toxicity, 1 hepatitis, 2 unknown. PFS at 1 year was 71% (95%CI:62-78) in the whole group of patients. The progression risk was significantly higher in patients both FCM+/CC+ compared with patients both FCM-/CC- (1-yr PFS 43% vs 74%) (HR 3.8 95%CI:1.6-9.0) (p=0.003). An higher but not significant risk of progression was found in pts discordant (FCM+/CC-) with respect to patients both FCM-/CC- (1-yr PFS 65% vs 74%) (HR 1.61, 95%CI:0.63-4.11) (p=0.315). In the univariate and multivariate analyses performed with Cox models, we found that the presence of ECOG PS≥2 (HR 2.14, 95%CI: 1.14-4)(p=0.018) and level of protein in CSF >40/ul (HR 1.83 95%CI: 1.01-3.29)(p=0.045) were prognostic factor of PFS. Conclusion: FCM assessment of CSF increase the rate of positivity of occult LD compare with CC but it's clinical relevance is still to be clearly defined. Our preliminary data suggest that patients both FCM+/CC+ have an higher risk of progression compared with those both negative, whereas discordant cases may have an intermediate prognosis. Disclosures: No relevant conflicts of interest to declare.

Abstract Abstract 2213 Coagulation factor VIII (FVIII) binds von Willebrand factor (VWF) at the D′D3 domain with high affinity. FVIII almost always circulates as a FVIII-VWF complex in blood. Our recent study has demonstrated that FVIII accelerates proteolytic cleavage of VWF by ADAMTS13 under mechanically induced fluid shear stress (Cao et al, PNAS, 2008). In this study, we sought to determine: 1) the domain of FVIII required for the enhancing effect on VWF proteolysis by ADAMTS13 under these conditions; 2) the physiological relevance of this enhancing effect on plasma VWF homeostasis in a murine model. First, we employed the novel vortex-based shear assay developed in the laboratory to assess the rate enhancing effect of various recombinant FVIII variants on VWF proteolysis by ADAMTS13. In these experiments, purified plasma VWF (150 nM) was incubated for 10 min with recombinant ADAMTS13 (50 nM) in the presence of various concentrations of recombinant FVIII variants (0-20 nM) in a total volume of 20 μl under constant fluid shear generated with a bench top mini-vortexer. This maneuver appears to produce ∼75 dyn/cm2 of fluid shear stress. Proteolytic cleavage product (∼350 kDa, the dimer of two C-terminal fragments linked by a disulfide bond) was then determined by 5% SDS-polyacrylamide gel electrophoresis and Western blotting. We showed that addition of a recombinant light chain of FVIII (FVIII-LC) increased the formation of proteolytic cleavage product as a function of increasing FVIII-LC concentrations. This rate enhancing effect was similar to that of full-length recombinant FVIII and B-domainless FVIII (FVIII-SQ). However, addition of a heavy chain of FVIII (FVIII-HC) or a light chain variant lacking the acidic (a3) region (FVIII-Δa3LC) did not increase the formation of cleavage product under the same conditions. These results suggest that FVIII-light chain is sufficient for accelerating VWF proteolysis by ADAMTS13 under physiological conditions. The rate enhancing effect of FVIII-LC depends on its high affinity interaction with VWF. Second, we determined plasma VWF antigen and multimer distribution in fVIII-/- and fVIII+/+ (WT) mice with same genetic background (C57BL/6) prior to and after reconstitution with recombinant FVIII-SQ and variants via a hydrodynamic approach. Plasma VWF antigen was determined by a sandwich ELISA assay and plasma VWF multimers were determined by 1% agarose gel electrophoresis and Western blotting. We showed that plasma VWF antigen levels in the fVIII-/- mice (n=18) were increased by ∼2.0 fold as compared with those in the WT mice (n=14). No difference in the ratio of ultra large (UL)-VWF to dimer was observed between the fVIII-/- mice and the WT mice (p>0.05). These data suggest that lack of FVIII may impair plasma VWF homeostasis. To assess whether plasma FVIII affects VWF proteolysis in vivo, plasma VWF multimer distribution was determined by agarose (1%) gel electrophoresis and Western blotting in the fVIII-/- mice 48 hours after injection of a series of endotoxin-free expression plasmids encoding various FVIII variants/fragments (i.e. plasmids diluted in 2 ml normal saline and injected into tail vein within 5 seconds). We showed that the ratio of the UL-VWF multimers to the dimer in plasma of fVIII-/- mice receiving normal saline alone was 1.70 ± 0.59 (means ± SD) (n=10). However, the ratios in plasma of fVIII-/- mice receiving plasmids encoding canine FVIII-SQ, human FVIII-SQ, human FVIII-HC+LC, and FVIII-LC were 0.44 ± 0.37 (n=20), 0.88 ± 0.18 (n=9), 0.40 ± 0.20 (n=5), and 0.97 ± 0.29 (n=9), respectively. These ratios were dramatically reduced compared with that in fVIII-/- mice receiving normal saline alone (p values<0.05∼0.001). Our hydrodynamic injection approach resulted in plasma levels of FVIII-SQ, FVIII-LC+HC and FVIII-LC between 150% and 200% of the WT. In contrast, a hydrodynamic injection of plasmid encoding human FVIII-HC or FVIII-Δa3LC did not prevent the accumulation of plasma UL-VWF multimers in fVIII-/- mice. We therefore conclude that FVIII, through the high affinity binding interaction between its light chain and D′D3 domain of VWF, may play a critical role in maintaining VWF homeostasis under (patho) physiological conditions. Disclosures: No relevant conflicts of interest to declare.

Abstract Abstract 1589 Poster Board I-615 Genome-wide, high-resolution analyses of copy number alterations (CNAs) now play an increasingly important role in identifying new genomic loci associated with leukemia biology and prognosis. The most powerful of these studies include large numbers of patients with associated clinical features and outcome data. Molecular Inversion Probes (MIPs) analyze genetic target sequences in parallel at the highest genomic resolution and can detect both gene copy number and allelic imbalance in clinical samples, and have been demonstrated to work on archived formalin-fixed paraffin-embedded (FFPE) samples as old as 20 years. In this pilot study, we report for the first time the successful interrogation of high-resolution CNAs in archived FFPE samples in childhood leukemia. We first extracted genomic DNA from FFPE bone marrow aspirate clots from 18 pediatric patients diagnosed with precursor B-cell acute lymphoblastic leukemia (pre-B ALL) diagnosed between 2006-2008 at Primary Children's Medical Center at University of Utah. DNA from paired remission samples was also extracted for each patient, again using archived FFPE bone marrow aspirate clots. Blast percentages on pre-B ALL marrow clots ranged from 39-99% (Mean 88%, Median 94%). Genomic DNA was isolated using RecoverAll” Total Nucleic Acid Isolation Kit for FFPE Tissues (Ambion®, Applied Biosystems). Clinical features and outcome data were readily available and abstracted from the medical record. The 18 patients in the FFPE cohort included: ages 2-21 years old (Median 5.5 years old), 7 females, presenting WBC 1-75 × 103/uL (Median 3.9), CNS negative disease (n=18), no reported cytogenetic abnormalities (n=8), t(12;21) [n=6], t(9;22) [n=1], and MLL rearrangement (n=1). 7 patients were designated “High Risk” by NCI-Rome Criteria and 1 patient relapsed. The MIP assay was run using the customized 330K Cancer Panel (Affymetrix®, Santa Clara, CA), which includes both cancer-specific SNPs and genome-wide coverage with a median probe distance of 4,207 basepairs (bp). Copy number was calculated by comparing leukemia samples to pooled normal control signal intensity for each probe. CNA calls were based on 5 consecutive probes with >90% call rate, standard deviation < 20%, and copy number ' 1.2 or ≥ 2.8. MIPs revealed remarkably high-quality CNA data for each of the 18 FFPE samples, including the cytogenetically “normal” patients. Both known and novel recurring CNA loci were identified in this cohort. Deletions included: 14q11.2 (n=11 [61%], 51569 bp, no known genes), 22q11.2 (n=10 [56%], 185944 bp, VPREB1), 14q32.33 (n=10 [56%], 631377 bp, no known genes), 7q34 (n=9 [50%], 292586 bp, PRSS1, TRY6, PRSS2), and 12p13.2 (n=6 [33%], 292586 bp, ETV6). Gains included: 10p15.2 (n=10 [56%], 26481 bp, PFKP), 10q26.3 (n=10 [56%], 69691 bp, MGMT), 10p11.21 (n=8 [44%], 922257 bp, FZD8, CCNY, GJD4), and 8p23.3 (n=7 [39%], 90307 bp, ARHGEF10). Interestingly, of 52 amplified segments recurring in 35% or greater of samples, all but one were located in chromosome 10, 14, 17, 18, or 21 suggesting genetic amplification hotspots. Additionally, 100% of IKZF1-deleted samples (n=2/2) compared to 37.5% of IKZF1-normal samples (n=6/16) had M3 marrows (>25% blasts) at Day 7. These same two IKZF1-deleted FFPE samples belonged to the patients with the two highest WBC values at presentation (75.3, 22.9 × 103/uL), in addition to containing two of the six highest bone marrow blast percentages at diagnosis. This is consistent with known findings that IKZF1 deletions are associated with high-risk ALL. In this pilot study of 18 patients, we have shown that archived FFPE bone marrow aspirate specimens (standard of care for all bone marrow procedures) can be used successfully for known and novel CNA analysis in childhood leukemia. We believe this is the first time that high-resolution, genome-wide CNA data from FFPE samples in any type of leukemia have been reported. This is an important development in CNA studies of hematological disease because now it is possible to investigate an unlimited number of archived FFPE childhood leukemia samples from around the world, or to explore rarer and more difficult to find specimens such as relapse or concordant identical twins. Disclosures No relevant conflicts of interest to declare.

Abstract Abstract 4630 Background: The prognosis of patient with relapsed or refractory CLL/SLL is dismal with an overall response rate (ORR) to salvage therapy for refractory patients of 10–30%, and limited survival benefit with current treatment approaches. Phase II studies of single agent lenalidomide in patients with relapsed or refractory CLL revealed an ORR of 32–58% (7-17% CR). Recent in vitro studies have shown that lenalidomide enhances the rituximab-induced killing of NHL cell lines and B-CLL cells by enhancing ADCC activity and restoring the defective T-cell and NK-cell mediated tumor cell cytotoxicity. Methods: Patients with relapsed or refractory CLL/SLL received oral lenalidomide via dose escalation as follows: 2.5 mg on days 1–7, 5 mg on days 8–14 and 10 mg on days 15–21 followed by 7 days of rest in 28-day cycle; for cycle 2 and beyond 20 mg was given on days 1–21 on a 28-day cycle. Rituximab was dosed at 375 mg/m2 IV weekly for 4 weeks starting on day 15 of cycle 1. Treatment was continued until disease progression or toxicity. Primary objectives were ORR (CR+PR) and safety and tolerability of the combination regimen. CT scans, and bone marrow biopsies were done every 2 months to assess for response (NCI-WG 2008). Peripheral blood and bone marrow aspirates were collected for correlative studies before lenalidomide was initiated, before rituximab was initiated (between days 13–15), after finishing treatment with rituximab and then every two months until disease progression. Flow cytometry was performed using the following antibodies CD3, CD4, CD5, CD8, CD19, CD20, CD23, CD40, CD45RA, CD62L, CD80, CD86, CD95, IL-17A and FoxP3. Panels were created for the analysis of T-cell memory/naïve populations, B-cell populations, regulatory T-cells and Th17 cells. Data was collected to a limit of 10,000 events of the population of interest. Data is presented as total number of cells/ul instead as percentage to avoid misinterpretation due to the dramatic reduction in the number of B cell lymphocytes after initiation of therapy. Subpopulation of T cells memory/naïve were compared with an age matched population of normal controls. Results: 18 patients with CLL/SLL were enrolled on study. Median number of prior chemotherapies was 3 (range 1–5). Median age was 63 years (range 42–80). High risk cytogenetic abnormalities (del11q (11%), del 17p/p53 (11%), complex (22%)) were observed in 44% of the patients. 95% of the patients had received prior fludarabine therapy and 50% were fludarabine refractory. Overall clinical benefit was seen in 92% of patients (42% PR, 50% SD) with a median duration of response of 18 months for patients who achieved a PR and 12 months for patients with SD. Although all responses were PR, the PR rate improved with continued therapy suggesting increased responses with a longer duration of treatment with lenalidomide. Most common adverse effects were neutropenia (50% grade 3–4), tumor flare (28% grade 1–2, 11% grade 3–4), fatigue (11% grade 1–2, 6% grade 3–4), venous thromboembolic disease (11% grade 3–4), acute renal insufficiency (11%), rituximab related infusion reactions (11%), flu-like symptoms (11%), infections (11%), and hypercalcemia (11%). Correlative studies showed that peripheral blood CD4 and CD8 effector memory subpopulations decreased after initiation of lenalidomide therapy with subsequent elevation after rituximab treatment on the CD4 effector memory compartment. The Th17 compartment was minimally decreased after initiation of lenalidomide while the levels of regulatory T cells (Tregs) appeared to decrease with lenalidomide therapy and increase slightly after rituximab. The expression of CD20 from bone marrow samples decreased as expected with rituximab therapy; however shortly after the discontinuation of rituximab CD20 expression was regained by the B cells compartment. Later time points will be presented at the meeting. Conclusions The combination of lenalidomide with rituximab is a promising with clinical activity in heavily pretreated patients with relapsed or refractory CLL. The combination appears tolerable with observed events consistent with the use of these two agents in other studies. The impact of lenalidomide on the T cell subpopulations in patients treated with rituximab remains unclear. A detailed analysis of the BM compartment at latter time points will be investigated. Disclosures: Lancet: Eisai: Consultancy; Celgene: Honoraria. Komrokji:Genentech: Research Funding.

Introduction: High dose chemotherapy (HDT) and autologous hematopoietic cell transplantation (AHCT) are considered standard of care as first line therapy in mantle cell lymphoma (Dreyling et al., 2005; Geisler et al., 2012) and in first line refractory and chemosensitive relapse Non-Hodgkin Lymphoma (NHL) (Philip et al., 1995) . The development of hematopoietic cell transplant comorbidity index (HCT-CI) (Sorror et al., 2009) for recipient selection and transplant risk evaluation have impacted on patient selection. Over the last decade, most transplant program have seen an increase in the median age of AHCT recipients(McCarthy et al., 2013). Limited data are available to optimise elderly patients selection for transplantation while minimising the risk of treatment related toxicity and mortality (TRM). The goal of this study was to identify factors impacting the safety and efficacy of AHCT in the elderly NHL patients in order to better select those who will benefit from this intervention. Method: This is a single center, retrospective study examining outcomes of AHCT in elderly patients (≥60 years old) with NHL. Between January 1st, 2008 and January 1st, 2015, 90 patients met the inclusion criteria and were included in the study. Patients signed an informed consent and the ethics committee of our institution approved the study. Progression-free-survival (PFS) and overall survival (OS) were analyzed according to age at time of transplantation, HCT-CI, lymphoma histology and disease status at time of transplant. Toxicities were analyzed according to age and HCT-CI. Results: Median age at time of NHL diagnostic was 60 years (range 42 to 68) and 63 years at time of transplant (range 60 to 69). One third (33%) of our cohort was ≥65 years old. Histologic sub-type was mainly composed of follicular (36%), mantle cell (20%) and large B-cell lymphoma (38%). 50% of patients had high-risk disease and 31% had low risk disease. HCT-CI was low-risk in 34%, intermediate risk in 40% and high-risk disease in 26%. BEAM/BEAC conditioning regimen was used in 94%. The median graft CD34+/kg cell dose infused was 4.87. The median time to neutrophil engraftment was 10 days (range 8 to 14 days) and platelet recovery was 16 days (range 11 to 43 days). The incidence of febrile neutropenia was 92% with 2% admission to the intensive care unit (ICU) with no difference between patients younger or ≥65 years old. Our cohort received a median of 8 days of antibiotics (range 0 to 41 days). Absolute lymphocyte count < 0,3 X 103 cells/uL at 14 days after transplant was associated with higher incidence of septic choc (p=0,024) and ICU admission (p=0,034). Age ≥65 year was not associated with an increase TRM and was surprisingly associated with less total parenteral nutrition (p=0,046) and narcotics uses (P=0,011). The median length of stay was 26 days. The median follow-up was 27 months (range, 1 to 87), median PFS of 46 months (Confidence Interval (CI); 95%, 24,4-67,6) (graph 1) and OS not reached (graph 2). The estimated 5 years OS is 62% and PFS is 40%. Transplant related mortality (TRM) was only 1% at 100 days and 2% at 1year after transplant. The only 2 patients who died from TRM died from cardiac arrest (1 month) and from an unknown cause (3 months). The 1-year progression rate was 30% (graph 3) and mortality rate only 12%. Progressive disease status following first line therapy was associated with a worse PFS compared to the achievement of a complete remission (Hazard Ratio (HR) 2,77; CI 95%, 1,18; 6,49). Progressive disease status at time of transplant was also associated with a lower PFS (HR 9,30: CI 95% 2,55 to 33,92) and OS (HR 13,44: CI 95% 2,68 to 67,48). HCT-CI score did not correlate with OS. International Prognostic Index (IPI), age and treatment type did not influence PFS or OS. Surprisingly, HCT-CI score did not correlate with toxicities, morbidity or mortality. Conclusion: In this single center retrospective study of elderly patients with NHL, AHCT was proven to be safe and effective. Progressive disease at the time of transplant was associated with worse PFS and OS. HCT-CI did not allow the categorization of patients in different prognostics group. Lymphocyte count at day 14 could identify patients at significant risk of complications. Our data suggest that age alone should not exclude patients from transplantation. However, HDT and AHCT should be reserved to chemosensitive patients and avoided in the elderly patient with progressive disease. Figure 1. Figure 1. Figure 2. Figure 2. Figure 3. Figure 3. Disclosures No relevant conflicts of interest to declare.

Abstract Abstract 4526 Introduction Autologous stem cell mobilization (SCM) is conventionally done using chemotherapy and G-CSF (G). Although safe and effective, patients (pts.) are exposed to risks of cytotoxic chemotherapy and myelosuppression. Plerixafor (P) and G mobilizes stem cells (SC) without any myelosuppression. Understanding the pharmacoeconomics (PE) of SCM is important so that the optimal approach can be used. Methods We studied PE of high dose cyclophosphamide (CY) and G SCM in 241 pts. (1/2004 to 3/2008) undergoing first autologous stem cell transplant and compared outcomes to projected costs using P+G. CY was dosed at 3 gm/m2 and G started the next day (10 mcg/kg) for 10 days with a planned first day of collection on day 11. Dose escalations were per institutional protocol. Pheresis was initiated if peripheral blood (PB) had >15 CD34+ cells/uL. PE analyses were done to compute total cost and included cost of CY, G, pheresis, product processing, and clinical events. Cost was based on Medicare part B physician, laboratory, and ancillary fee schedule and was calculated from review of random patient records. This approach removed the bias of inter-institutional cost variations. Ideal Outcome (IO) was defined as >2×106 CD34+ cells/kg collected on the planned day of collection in 1 or 2 apheresis without a preceding negative event that lead to additional evaluation in clinic or inpatient. Results 141 (61%) were males; 121 (50%) had myeloma (MM), 115 (48%) had lymphoma (L) and 5 had other diagnoses; 61 (25%) received radiation with prior therapy. Median WBC and neutrophil count prior to CY was 5.3 ×109 /L (range, 1.7 to 46), and 3.3 ×109/L (range, 0.95-31.37). 199 (82.6%) started pheresis on the planned first day of pheresis, 18 (7.9%) had a delay in start of pheresis (range, 1- 7 days) due to low PB CD34 count and 24 (9.9%) pts. did not proceed to pheresis due to low PB CD34+ cell count. The mean final SC dose was 10.22 ×106 CD34/kg (range, 0.45 - 60.18). Pts. with MM collected more than lymphoma (11.98 vs. 6.35, P<0.0001). 6 (2.8%) pts. collected <2 ×106 CD34/kg. Median number of pheresis was 1 (range, 0 - 4) with 41 (17%), and 10 (4.1%) requiring 2 and 3 pheresis, respectively. The target SC dose of >6×106 CD34/kg in MM pts. was collected in 1,2, or 3 pheresis in 84 (69.4%), 98 (80.9%), and 102 (84.2%), respectively. In L pts., the target SC dose of >2×106 CD34/kg was collected in 1, 2, or 3 pheresis in 68 (59%), 85 (73.9%) and 90 (74.3%), respectively. Clinical events included: febrile neutropenia (FN) clinic evaluation (7, 2.9%); FN admission (26, 10.8%); line infection (7, 2.9%); line change (8, 3.3%), gastrointestinal side effects (111, 46%), bone pain with evaluation in clinic (127, 52%) and admission for management of bone pain (9, 3.7%). Forty-three (18%) pts. were hospitalized for clinical events. IO was seen in 48 (20%) pts. 23% of MM and 15.7% of L pts. had an IO. Risk factors including prior radiation, WBC count and ANC prior to CY could not predict ability to collect SC or IO. Mean total cost of CY+G SCM was $10,732 (range, 6988-30827). IO was associated with a lower cost in overall group, (mean, $10,371 vs. $12,870, P=0.001), in MM pts. (mean, $10,511 vs. $12,152, P=0.026), and in L pts. (mean, $10,133 vs. $13,627, P=0.006). Assuming a similar distribution of IO in 100 pts. with MM and L, the projected per pt. cost of SCM would be $11,774 and $13,067 (mean, $12,421) with CY+G. Projected costs of SCM using P+G (based on published phase III data that used G dose of 10 mcg/kg without dose escalation and that the non-mobilizers had a maximum of 4 days of P) for 100 pts. with MM and L would be $12,852 and $8986 (mean, $10,919). These do not take into account costs associated with operational planning and predictability of the date of SCM with P+G, impact of the negative event on pts. quality of life with CY+G, effects of mobilization failure leading to other alternative clinical approaches including an allogeneic stem cell transplant (N=6). Conclusion Our study shows that SCM with CY+G is associated with a low incidence of IO. P+G can be justified as upfront method of SCM in pts. with MM and L from a PE perspective without any detrimental impact on SCM efficiency. As P+G is not associated with any negative clinical events related to myelosuppression, it should translate into a better quality of life for pts. SCM using P+G may allow for optimal utilization of resources which again will impact PE. These need to be validated and should be addressed in future studies of SCM. Disclosures: Jagasia: Genzyme: Research Funding.