ALBERT

Description: Abstract 422 Background: Antibody-dependent cell-mediated cytotoxicity (ADCC), largely mediated by natural killer (NK) cells, is thought to play an important role in the efficacy of rituximab, an anti-CD20 monoclonal antibody (mAb) used to treat patients with B cell lymphomas. CD137 is a costimulatory molecule expressed on a variety of immune cells following activation, including NK cells. We hypothesized that the anti-lymphoma activity of rituximab could be enhanced by stimulation of NK cells with an anti-CD137 agonistic mAb. Methods: Rituximab induced upregulation of CD137 on NK cells was assessed using lymphoma cell lines and primary lymphoma patient samples. In-vitro NK cell degranulation and cytotoxicity were assessed by CD107a mobilization and chromium release. A murine lymphoma tumor model targeted by mouse anti-mouse CD20 mAb was used to assess in-vivo synergy of anti-CD20 and anti-CD137 mAbs. Mechanism of synergy was explored by T cell, NK cell, and macrophage depletion in the immune competent mouse model. A xenotransplant model in SCID mice with disseminated, luciferase-labeled lymphoma was used to demonstrate efficacy of anti-CD137 mAb and rituximab, and sufficiency of an innate immune response. Results: NK cells in human primary lymphoma samples do not express CD137 at baseline, however these cells highly upregulate CD137 when encountering rituximab-coated tumor B cells. Rituximab-induced NK cell degranulation and cytotoxicity as measured by CD107a mobilization (p=.006) and chromium release (p=.01) are enhanced by anti-CD137 agonistic mAb. In a murine lymphoma model, anti-CD137 mAb significantly enhances anti-tumor activity of anti-CD20 mAb leading to complete tumor resolution (p

Description: Abstract 2093 Background: Adoptive immunotherapy is a promising novel approach to the treatment of cancer. However, clinical translation of adoptively transferred CD4 T cells is limited by cotransfer of an inhibitory population of regulatory CD4 T cells (Tregs). We identified a method of isolating viable antitumor CD4 T cells while excluding Tregs based on two surface markers—CD44 and CD137. Methods: We have developed a model for adoptive cell therapy of lymphoma whereby anti-tumor T cells are generated in vivo through vaccination with a CpG-loaded whole cell vaccine (CpG/H11). These vaccine-induced cells can protect from lethal tumor challenge when isolated and transferred into lethally irradiated, syngeneic recipient mice. We investigated the subsets of T cells involved in the anti-tumor response through a combination of in vitro and in vivo assays. Results: Adoptive transfer of CD137negCD44hi CD4 T cells, but not other sub-populations, provided protection from B cell lymphoma. We demonstrate that the population of CD137posCD44hi CD4 T cells consists primarily of activated Tregs. In vitro, these CD137pos cells suppressed the proliferation of effector cells in a contact-dependent manner. We observed that this CD137pos Treg population persisted following adoptive transfer and maintained expression of FoxP3 as well as CD137. Moreover, the addition of CD137posCD44hi CD4 cells to CD137negCD44hi CD4 cells suppressed the antitumor immune response. In the presence of CD137posCD44hi CD4 T cells, homing of other T cell populations to tumor sites was disrupted. These results suggest that CD137 expression on CD4 T cells defines a population of activated Tregs that prevent antitumor immune responses. Conclusions: Our findings identify two surface markers that can be used to facilitate the enrichment of anti-tumor CD4 T cells while depleting an inhibitory Treg population. This approach has direct applicability to clinical trials for patients with lymphoma. Disclosures: No relevant conflicts of interest to declare.

Description: Abstract 2791 Introduction: Elderly mantle cell lymphoma (MCL) patients (pts) do not benefit from dose-intensive chemotherapy upfront.1 The GOELAMS group recently demonstrated that a regimen comprising Vincristine/Adriamycine/Dexamethasone plus Chlorambucil (VAD+C) was well tolerated, had a good efficacy/toxicity profile and induced similar PFS than R-CHOP (median PFS between 16 to 18 months2,3,4). Additionally, it has been shown that bortezomib (Velcade®), with or without Rituximab has efficacy in relapsed/refractory MCL patients5,6. These data prompted, our group to conducte a phase II prospective non randomized clinical trial evaluating the combination of Velcade plus Rituximab/Adriblastine/Dexamethasone/Chlorambucil (RiPAD+C) as a first line therapy for elderly MCL patients. Aims: To evaluate the overall response rate (ORR) and toxicity after 4 cycles of RiPAD+C regimen (main objective) and to evaluate prognostic factors for survival (secondary objective). Protocol: RiPAD+C : Rituximab 375 mg/m2 on d1 (and d8 for cycle 1); PS 341, Velcade® 1.3 mg/m2 on d1, 4, 8 and 11; Adriblastine 9mg/m2/d as a continuous infusion for 4 days; Dexamethasone 20 mgx2/d from d1 to d4; Chlorambucil 12 mg/d, d20 to d29. Repeat cycles every 35d. After 4 cycles, responding pts (Cheson 1999 criteria) received 2 additional cycles for a maximum of 6. Patients and methods: Inclusion criteria: All untreated elderly (65 to 80 years old) MCL patients (including blastoid forms) presenting with a stage II to IV disease with a good PS (ECOG

Description: Abstract 144 Introduction: Mantle cell lymphoma (MCL) is an aggressive non-Hodgkin's lymphoma. Although newer treatment regimens including intensive chemo-immunotherapy followed by stem cell transplant have improved survival to a median approaching 6 years, MCL is still incurable in many cases. The use of flow cytometry to investigate stimulation induced signaling at the single cell level represents an opportunity to obtain each patient's signaling profile as well as to discover tumor cell heterogeneity and identify signaling events potentially responsible for poor outcomes. We recently used this method to characterize signaling in subpopulations of tumor samples from patients with follicular lymphoma (FL). In FL, we identified a lymphoma negative prognostic (LNP) cell subset with impaired B cell antigen receptor (BCR) signaling, the prevalence of which correlated with adverse clinical outcome (Irish et al., PNAS 2010). In the present study we used the same approach to identify signaling responses with large variation within MCL patient samples, and tested whether these signaling events might predict patients' clinical outcomes. By understanding the biology based on lymphoma signaling profile, we might identify prognostic significant factors such as the LNP subset observed in FL. Method: Single cell flow cytometry measurements of signaling were acquired for samples of MCL (n=25). Of these, 21 MCL specimens were obtained prior to any treatment. Median age was 61 years, and follow up time ranged from ½ until 15 years. Treatment regimens varied. Samples from diffuse large B cell lymphoma (DLBCL, n=12), FL (n=14), chronic lymphocytic leukemia (CLL, n=14) and tonsils from healthy donors (n=4) were also included for comparison. Phosphorylation of 14 signaling proteins was measured under 12 different stimulation conditions in every cell within the patient specimens, including lymphoma B cells and in tumor-infiltrating T cells. Stimulation conditions included BCR crosslinking, CD40 ligand, CpG oligodeoxynucleotides (CpG ODN) and several cytokines (IL-4, IL-10, IL-21, IFN-γ). Result: The magnitude of most cytokine induced signaling responses in lymphoma cells from MCL patients was higher than in lymphoma cells from FL. This included IL-10 induced phosphorylation of STAT3 (p

Description: Abstract 2006 Background: Several gene expression signatures predict survival in diffuse large B cell lymphoma (DLBCL), but the lack of practical methods for genome scale analysis has limited translation to clinical practice. Methods: We examined the power of individual genes to predict survival across different therapeutic eras. In studying 787 patients with DLBCL, we built and validated a simple model employing one gene expressed by tumor cells and another expressed by host immune cells, assessing added prognostic value to the clinical International Prognostic Index (IPI). We validated models in an independent cohort using diagnostic formalin-fixed specimens. Results: We verified expression of LMO2 as an independent predictor of survival and ‘Germinal Center B-cell’ subtype. We identified expression of TNFRSF9 from the tumor microenvironment, as the best in bivariate combination with LMO2. We studied distribution of TNFRSF9 tissue expression in 95 patients. A model integrating these two genes (TGS) was independent of ‘cell of origin’ classification, ‘stromal signatures’, IPI, and added to the predictive power of the IPI. This bivariate model and a composite score integrating the IPI (TGS-IPI) performed well in three independent cohorts of 545 previously described patients. Both models robustly stratified outcomes in a simple assay of routine specimens from 147 newly diagnosed patients as depicted. Conclusion: Measurement of a single gene expressed by tumor cells (LMO2) and a single gene expressed by the immune microenvironment (TNFRSF9) powerfully predicts overall survival in patients with DLBCL. A simple test integrating these two genes with the IPI can readily be used to select patients of different risk groups for clinical trials. Disclosures: No relevant conflicts of interest to declare.

Description: Abstract 1758 Background: The LyMa trial is established as a randomized, open-label, phase III study, to evaluate the efficacy of rituximab maintenance after autologous stem-cell transplantation (ASCT) in untreated mantle cell lymphoma (MCL) patients aged between 18 and 65 years old. The LyMa trial opened in September 2008. As of July 2010, 114 patients have been included. As in many other lymphoma entities, R-CHOP is still considered a standard of care for upfront MCL patients before ASCT. However, only 30–40% of MCL patients reach CR/CRu after R-CHOP. Since the response status (CR vs PR) before ASCT is associated with a better outcome it is important to find new alternative induction chemotherapy regimen. Growing evidences suggest that high-dose aracytine (HA) could be a major drug in MCL and should not be considered only at relapse. Several groups have highlighted a good response rate after upfront HA. More than 80% of the patients reach CR/CRu after intensive hyperCVAD/MTX regimen. The MCL2 trial from the Nordic group and the GELA trials have also demonstrated that higher response rates are achievable by alternating HA and R-CHOP. Therefore, the LyMa trial was designed to use 4 courses of R-DHAP (Rituximab 375mg/m2 D1; Dexamethasone 40mg D1-4; High-dose Aracytine 2×2 g/m2 D2 and Cisplatin 100 mg/m2 D1 but the choice of platinum salt was left at the discretion of local investigator) as induction therapy followed by ASCT using R-BEAM for newly diagnosed MCL patients. According to the design of the trial, only R-DHAP refractory patients (defined as a tumor burden reduction lower than 75% or progression) are eligible for R-CHOP prior ASCT. Aims: The present analysis was performed in july 2010 and aims to evaluate prospectively the response rate after 4 courses of R-DHAP. All patients included before January 2010 (n=64) were eligible for the purpose of this analysis. Patients' characteristics: Median age is 57 years old (range, 30–65) and 53 (83%) patients are males. At time of diagnosis, 49 patients presented with Ann Arbor stage IV disease. All biopsies were centrally reviewed by pathologist experts from the GOELAMS and GELA groups. MCL diagnosis was confirmed in all reviewed cases. Eleven patients had a blastoid variant. Treatment: One patient withdraws is informed consent prior the start of the first cycle of R-DHAP. This patient has been excluded from the present analysis. All the other patients (n=63) have received at least one course of R-DHAP. Over the four courses of R-DHAP, 15, 24, 29 and 33 patients received another platinum salt than cisplatin. Four courses of R-DHAP were administered to 58 patients. For the remaining 5 patients, treatment was stopped for toxicity reason (n=3) or disease evolution (n=2). The two patients who progressed while on therapy received R-CHOP but both did not responded and died. Stem-cells were collected after more than 2 cytapheresis in only 4 cases. To date, fifty-three patients (84%) out of 63 underwent ASCT. Response rate: in an intention to treat analysis, the ORR after 4 courses of R-DHAP is 92% including 32 patients who reached CR and 20 patients who reached CRu according to Cheson criteria (JCO 1999). Taken together, the CR/CRu rate after 4 courses of R-DHAP is 82.5%. Conclusion: R-DHAP alone is feasible with limited toxicity. This result of the ongoing LyMa trial confirms the major impact of HA in MCL untreated patients showing CR/CRu rates that are superior to those usually obtained with R-CHOP alone or alternating protocols such as R-CHOP/R-DHAP. FDG-PET analysis and response at the molecular level after 4 RDHAP courses have also been analyzed. Disclosures: Off Label Use: velcade is of label in France for the treatment of mantle cell lymphoma. Tilly:Amgen: Honoraria.

Description: Abstract 5002 Background: Kidney failure is a major cause of morbidity in patients with Multiple Myeloma (MM). While up to half of MM patients can be shown to have renal impairment, 10% will become dialysis dependent. The main mechanism of kidney failure is cast nephropathy, which is linked to high amounts of circulating free light chains. A proposed strategy to prevent this outcome is the use of extended high cutoff (HCO) dialysis. An ongoing randomized controlled trial is testing the Gambro HCO1100 filter. Here we report the use of another dialyzer (Bellco Phylther), which has a smaller pore size than the Gambro filter, but which may prove to be as effective and is less costly. Methods: We present three patients with symptomatic MM, elevated κ or λ serum free light chains (〉500mg/L), biopsy confirmed cast nephropathy, and kidney failure (estimated GFR 50%) and rapid reductions in sFLCs. These reductions were sustained at 3 months in all cases, likely because of effective anti-myeloma treatment. Two of the three patients had recovery of kidney function and remain dialysis-independent at least 6 months after cessation of dialysis. Interestingly, the only patient that did not recover kidney function was also found to have tubulointerstitial disease on renal biopsy in addition to cast nephropathy. Conclusions: The HCO Bellco Phylther dialyzer appears effective in the rapid reduction of sFLCs in light chain MM patients with cast nephropathy requiring dialysis and concurrent anti-myeloma drug therapy. While the numbers are small, our review suggests that patients with uncomplicated MM cast nephropathy may benefit from aggressive hemodiafiltration with this HCO membrane. This dialysis membrane and protocol are worth considering for further study in patients with MM cast nephropathy. Disclosures: No relevant conflicts of interest to declare.