ALBERT

Beschreibung: The 26S proteasome plays a vital role in degrading regulatory proteins such as p53, p21, p27, NF-kB, I-kB, and bcl-2, that govern cell cycle, transcription factors activation, apoptosis and cell trafficking. Thus, the mechanisms by which bortezomib elicits its antitumor activity may vary among tumor types, and the extent to which each affected pathway is critical to the inhibition of tumor growth could also differ. The aim of this study was to determine the efficacy and toxicity of bortezomib in previously pretreated patients with peripheral T-cell lymphoma unspecified (PTCLU) and cutaneous T-cell lymphomas (CTCL). Each patient had to meet the following inclusion criteria to be enrolled in the study: histologically confirmed PTCLU or CTCL (according to REAL/WHO classification); any stage, any IPI, any bone marrow status; second or more relapse or refractory disease; age ≥ 18; ECOG performance status ≤ 2; Hb ≥ 10 g/dL, ANC ≥ 1.5x109/L and platelets ≥ 100 x 109/L; normal hepatic, renal and cardiac functions; and voluntary written informed consent. Bortezomib was given at 1.3 mg/m2 IV push on days 1, 4, 8 and 11 every 21 days. Restaging was done every 2 cycles. Patients were treated for up to a total of 6 cycles unless removed from study for failure to respond or toxicity. The response criteria were those recommended by NCI sponsored Working Group. A total of 30 patients will be enrolled; so far 10 patients entered and preliminary results of this trial will be presented.

Beschreibung: Mantle cell lymphoma (MCL) is an aggressive B-cell malignancy with a median survival of 3 years despite chemoimmunotherapy. Rituximab, a chimeric anti–CD20 monoclonal antibody (mAb), has shown only modest activity as single agent in MCL. The humanized mAb milatuzumab targets CD74, an integral membrane protein linked with promotion of B-cell growth and survival, and has shown preclinical activity against B-cell malignancies. Because rituximab and milatuzumab target distinct antigens and potentially signal through different pathways, we explored a preclinical combination strategy in MCL. Treatment of MCL cell lines and primary tumor cells with immobilized milatuzumab and rituximab resulted in rapid cell death, radical oxygen species generation, and loss of mitochondrial membrane potential. Cytoskeletal distrupting agents significantly reduced formation of CD20/CD74 aggregates, cell adhesion, and cell death, highlighting the importance of actin microfilaments in rituximab/milatuzumab–mediated cell death. Cell death was independent of caspase activation, Bcl-2 family proteins or modulation of autophagy. Maximal inhibition of p65 nuclear translocation was observed with combination treatment, indicating disruption of the NF-κB pathway. Significant in vivo therapeutic activity of combination rituximab and milatuzumab was demonstrated in a preclinical model of MCL. These data support clinical evaluation of combination milatuzumab and rituximab therapy in MCL.

Beschreibung: The primary end point of the study was the successful mobilization of a target cell dose of 2 x 106 CD34+ cells/kg in lymphoma patients receiving ifosfamide, epirubicin and etoposide (IEV) chemotherapy and a fixed dose (6 mg) of pegfilgrastim given as single subcutaneous injection. An open-label phase II study including 25 relapsed or refractory patients (Hodgkin’s disease=4; aggressive non-Hodgkin’s lymphoma=21) was conducted to evaluate the efficacy of pegfilgrastim, in combination with salvage chemotherapy, mobilizing CD34+ stem cells into peripheral blood. Following chemotherapy, all patients had grade 4 neutropenia with a median duration of 1.5 days (1–3). Pegfilgrastim treatment was well tolerated and only 2/25 patients required pain-control medication. CD34+ cells were mobilized in all patients. The median (range) peak value of peripheral blood CD34+cells after IEV chemotherapy and pegfilgrastim was 141/microL (12.8–386) and occurred almost invariably on day +14 (13–16). Twenty three/25 patients underwent a single apheresis to collect a median of 8.7 CD34+cells/Kg (1.8–17.3). Twenty four/25 patients (96%) reached the target cell dose of 2 x 106 CD34+ cells/kg. High concentrations of circulating CD34+ cells (〉 50/microL) were observed for several days after the achievement of the peak value. All patients have been transplanted with pegfilgrastim-mobilized CD34+ cells and all of them showed a rapid and sustained engraftment after high-dose chemotherapy. Our results show that pegfilgrastim as adjunct to chemotherapy is a predictable and highly effective mobilization regimen in lymphoma patients

Beschreibung: Abstract 2378 Epstein-Barr virus (EBV) is a ubiquitous, gamma herpes virus that infects human epithelial cells and B lymphocytes. Over 90% of adults worldwide are infected with EBV and, collectively, this virus is associated with a broad spectrum of benign and malignant disease. EBV is a potent oncogenic virus and is capable of efficiently transforming B cells in both in vitro and in vivo models. While signaling cascades contributing toward B cell immortalization and transformation following EBV infection have been described, epigenetic events that contribute toward the B cell transformation process remain poorly characterized. EBV-transformed lymphoblastoid lines (LCL) and spontaneous B cell lymphomas that arise in the hu-PBL-SCID model of EBV-induced lymphomagenesis show abundant expression of the protein arginine methyltransferase 5 (PRMT5), a type II PRMT enzyme that catalyzes symmetric dimethylation of arginine residues on histones and non histone proteins (P53, CYCLIN D1). PRMT5 partners with multiple co-repressor proteins such as HDAC2, MBD2 and DNMT3a to silence multiple regulatory and tumor suppressor gene products. All EBV-transformed B cell lines and primary tumors showed cytoplasmic and nuclear staining for PRMT5 and its associated epigenetic marks symmetric dimethyl histone 3, arginine 8 (S2Me-H3R8) and S2Me-H4R3. Resting and activated B cells did not demonstrate PRMT5 over expression or associated global epigenetic marks. Infection of primary human B cells with the B95.8 strain (but not mutant P3HR1 or inactivated EBV) led to dysregulated expression of PRMT5 as early as day 4 post infection. By day 8 post EBV infection, PRMT5 location had transitioned to the nucleus and this localization coincided with acquisition of S2Me-H4R3 and S2Me-H3R8 and loss of the asymmetric epigenetic mark 2Me-H4R3,a type I PRMT histone mark. PRMT5 over-expression was dependent on LMP-1-driven NFkB activity and transcriptional silencing of miR96 expression, a micro RNA that targets the PRMT5 3'UTR. To determine if PRMT5 over expression was essential for induction and maintenance of the transformed phenotype, we infected resting B cells with EBV and, at various time points (day 4, 7, 14 or 21), added a novel, highly selective small molecule inhibitor of PRMT5 activity, an inactive small molecule control, shRNA specific for PRMT5 or control shRNA. Absolute CD19+ cell counts and confocal microscopy experiments to monitor PRMT5 and its epigenetic marks were performed and showed that PRMT5 activity was critical for EBV-driven B cell transformation to proceed. PRMT5 inhibition of resting or activated B cells did not result in any loss of viability. Global transcriptome analysis identified several tumor suppressor genes, including the protein tyrosine phosphatase PTPROt, were silenced during EBV-driven B cell transformation. Chromatin immune precipitation (ChIP)-sequencing using monoclonal antibodies specific for PMRT5 and S2Me-H3R8 (or control IgG) confirmed the PTPROt promoter to be directly targeted by PRMT5 and PTPROt transcript was found to become silenced during EBV-driven B cell transformation. Real time PCR and RNA-seq showed PTPROt transcript to become restored with PRMT5 inhibition. PTPROt expression led to dephosphorylation and inhibition of the LYN, SYK, and Bruton's Tyrosine kinase (BTK) kinase proteins, critical proteins involved in regulation of the B cell receptor (BCR). This model provided us with direct evidence that PRMT5 activity is critical to EBV-driven B cell transformation and supports our hypothesis that PRMT5 dysregulation drives epigenetic events that directly contribute to key initiating events during B cell transformation as well as to the maintenance of the malignant phenotype. We believe this is the first example of oncogenic virus driving over expression of an epigenetic modifier that catalyzes placement of global repressive epigenetic marks that silence of regulatory and tumor suppressor genes. This data justifies pursuit of experimental therapeutic strategies focused on selective PRMT5 inhibition in cancer. Disclosures: No relevant conflicts of interest to declare.

Beschreibung: Abstract 2788 Preclinical studies conducted at our institution (Alinari et al. Blood Abstract 1694, 2009) demonstrated superior efficacy of milatuzumab (Immunomedics, Inc.), a humanized anti-CD74 antibody, in combination with rituximab in mantle cell lymphoma (MCL) cell lines, MCL patient (pt) primary tumor cells, and an in vivo preclinical model of human MCL, compared to either agent alone. Veltuzumab (Immunomedics, Inc.), a novel humanized anti-CD20 antibody, has been reported to have several advantages over rituximab including slower off-rates, shorter infusion times, higher potency, and improved therapeutic responses in animal models. Phase II clinical testing of veltuzumab demonstrated single agent activity in pts with relapsed and refractory non-Hodgkin's lymphoma (NHL). In vitro, veltuzumab combined with milatuzumab also resulted in enhanced apoptosis compared to either agent alone, similar to that observed with rituximab and milatuzumab (Fig 1). As a result of the anti-tumor activity observed in vitro with combined veltuzumab and milatuzumab, we initiated a phase I/II trial in pts with relapsed or refractory B-cell NHL after at least 1 prior therapy to determine the safety, tolerability, and overall response rate with this combination. Patients received veltuzumab 200 at mg/m2 weekly combined with escalating doses of milatuzumab at 8, 16, and 20 mg/kg twice per wk of wks 1–4, 12, 20, 28, and 36. All pts received pre-medication with acetominophen, diphenhydramine, and famotidine prior to each veltuzumab dose and acetominophen, diphenhydramine, and hydrocortisone 50 mg before and after each milatuzumab dose. Dose limiting toxicity was defined during weeks 1–4. Six pts with grade 2 (n=2) or 3 (n=4) follicular NHL, have completed at least 4 weeks of combined veltuzumab and milatuzumab. Median age was 63.5 years (range 44–81), and pts received a median of 3.5 prior therapies (range 3 – 5), including 2 pts with prior autologous stem cell transplant. Three of 6 patients were refractory to rituximab, defined as having less than a partial response to the last rituximab-containing regimen. Dose escalation has reached 16 mg/kg milatuzumab, and no dose limiting toxicities have been observed to date. However, 3 of 6 pts experienced grade 3 infusion reactions during or immediately following the milatuzumab infusion; 1 pt treated with 8 mg/kg milatuzumab during weeks 1 and 12, and 2 pts receiving 16 mg/kg during weeks 3 and 12. Grade 3 infusion reactions consisted of fever, rigors, nausea, vomiting, diarrhea, and in 1 case a diffuse macular rash. Grade 3–4 hematologic toxicity occurred in only 2 pts consisting of grade 4 lymphopenia, and no infections have been observed. The most frequently observed grade 1–2 toxicities were fatigue, transient hyperglycemia, dyspnea, hypoalbuminemia, and thrombocytopenia. Human anti-veltuzumab and anti-milatuzumab antibodies, collected in all 6 pts pretreatment and day 1 of weeks 4 and 12, have not been detected in any pt. Plasma cytokine levels of IL-10, IL-12, TNF-α and INF-γ were checked pre- and post- veltuzumab infusion on day 1 and pre- and post-milatuzumab infusion on day 2. While elevations in cytokine levels were observed, there was no correlation with infusion reactions or response. In the first cohort, one pt achieved a PR maintained at week 20, 1 pt experienced stable disease at week 10, and 1 pt developed progressive disease at week 20. In the second cohort, two pts achieved a PR at week 10, and 1 pt had stable disease at week 10. Two of 3 responding pts were rituximab-refractory. Due to the observed infusion reactions with milatuzumab, the protocol has been amended to include additional premedication with intravenous antihistamine, and dexamethasone 20 mg pre-milatuzumab and 10 mg post-milatuzumab. The schedule of treatment was also modified so that the antibodies are no longer administered on the same day. Dose escalation will continue and updated results will be presented. The first 2 cohorts will be expanded to 6 pts to determine if the modifications will limit the infusion reactions and permit prolonged dosing in responding pts. In summary, 3 of 6 pts with relapsed or refractory NHL treated to date including heavily pretreated and rituximab-refractory pts, responded to combination therapy, achieving a PR. The primary observed toxicity has been infusion reactions due to milatuzumab. Disclosures: Christian: Immunomedics, Inc.: Research Funding. Off Label Use: The use of the monoclonal antibodies veltuzumab and milatuzumab is experimental in the treatment of non-Hodgkin's lymphoma. Benson:Immunomedics, Inc: Research Funding. Jones:Immunomedics, Inc.: Research Funding. Wegener:Immunomedics, Inc.: Employment, shareholders. Goldenberg:Immunomedics, Inc.: Employment, shareholders. Baiocchi:Immunomedics, Inc.: Research Funding. Blum:Immunomedics, Inc.: Research Funding.

Beschreibung: Introduction: Both lenalidomide and monoclonal antibodies targeting the immune checkpoint PD-1, including nivolumab, have single agent activity in subsets of patients with Hodgkin lymphoma (HL) and Non-Hodgkin lymphoma (NHL). Lenalidomide mediates increased T cell IL-2 production and may enhance T and NK cell response to immune checkpoint blockade resulting in synergistic activity, but with potential for overlapping immune related toxicities. We conducted a phase I study to determine the safety, tolerability, and maximum tolerated dose (MTD) of nivolumab and lenalidomide in patients with relapsed/ refractory (R/R) HL and NHL. Methods: Patients (age ≥18 years) with R/R B-cell NHL who were transplant ineligible or patients with R/R HL with ≥ 2 prior lines of treatment were eligible (NCT03015896). Inclusion criteria included ECOG performance status ≤ 2, creatinine clearance ≥ 40 mL/min, platelets ≥ 100,000/mm3, absolute neutrophil count (ANC) ≥ 1,500/mm3, and bilirubin ≤ 1.5 times the upper limit of normal. The primary objective was to determine the MTD of lenalidomide when combined with nivolumab given at standard fixed dosing. Nivolumab was administered as 240 mg IV every 2 weeks; lenalidomide was administered orally on days 1-21 of 28-day cycles. Aspirin 81 mg daily was required for thromboprophylaxis in patients not already receiving therapeutic anticoagulation. Dose escalation of lenalidomide was performed using a 3+3 design, with dose levels (DL): 10 mg (DL -1), 15 mg (DL 1), and 20 mg (DL 2). Dose limiting toxicity (DLT) was defined within cycle 1 as grade Gr 3 or 4 non-hematologic toxicity, Gr 3/4 febrile neutropenia, any Gr 5 toxicity, or either ANC ≤ 500/mm3 or platelets 〈 25,000/mm3 persisting 〉 seven days. Adverse events (AEs) were reported using CTCAE Version 4.0. Responses were investigator assessed according to the 2014 Lugano criteria. Results: Ten patients were enrolled. The median age was 68.5 (range 23-80), 5 were male, and the histologic diagnoses included diffuse large B cell lymphoma (DLBCL) in 5 patients (1 GCB, 4 non-GCB including 2 double expressor), high grade B cell lymphoma (HGBCL) in 1 patient, HL in 3 patients, and lymphoplasmacytic lymphoma in 1 patient. Two DLTs occurred at DL 1: Gr 3 rash requiring dose interruption and subsequent dose reduction in one patient and Gr 3 generalized weakness in a patient with rapidly progressive disease, considered possibly related to therapy. Six patients were treated at DL -1 with no DLTs. Gr ≥ 3 AEs occurred in 9/10 patients (Table 1). Neutropenia occurred in 7/10 patients: Gr 4 in two patients (both DL1), Gr 3 in four patients, and Gr 2 in one patient. Gr 3 rash occurred in two patients, and Gr 3 lung infection (pneumonia), Gr 3 fatigue, and Gr 3 duodenal hemorrhage (at site of DLBCL involvement) all occurred once respectively. Thromboembolic events occurred in two patients, one Gr 3 and one Gr 2. One Gr 4 non-hematologic AE occurred, Gr 4 respiratory disorder (COPD exacerbation) considered unrelated to treatment. One patient with rapidly progressive HGBCL prior to study entry died on study due to disease progression. Immune related AEs included Gr 1 hypothyroidism and Gr 1 fever in one patient. Common non-hematologic AEs of any grade are summarized in Table 2. Therapy related AEs lead to treatment discontinuation in one patient (Gr 3 rash and Gr 3 neutropenia); three additional patients required dose reductions of lenalidomide due to therapy related AEs. As of July 1, 2019, one patient remains on treatment. Therapy was discontinued for disease progression in five patients, including one patient who died on study from progressive disease. Three patients discontinued treatment without progression in order to pursue definitive therapy (axicabtagene ciloleucel, autologous transplant, and allogeneic transplant respectively). Three patients achieved an objective response, one complete response and two partial responses, with an additional three patients with best response of stable disease, two of whom discontinued for alternative therapies without progression of disease. Conclusions: We determined the MTD in R/R HL and NHL to be 10 mg lenalidomide in combination with 240 mg nivolumab. Treatment discontinuation due to toxicity was uncommon as were immune related AEs. A pre-planned phase 2 study in DLBCL and dose expansion study in HL is underway to evaluate preliminary efficacy of this combination at the MTD. Disclosures William: Techspert: Consultancy; Celgene Corporation: Consultancy; Kyowa Kirin, Inc.: Consultancy; Guidepoint Global: Consultancy; Defined Health: Consultancy. Brammer:Celgene: Research Funding; Seatlle Genetics: Honoraria, Speakers Bureau. Christian:Genentech: Membership on an entity's Board of Directors or advisory committees, Research Funding; Immunomedics: Research Funding; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Triphase: Research Funding; Merck: Research Funding; Janssen: Research Funding; Cephalon: Research Funding; Bristol-Myers Squibb: Research Funding; Acerta: Research Funding; Celgene: Research Funding; Millennium Pharmaceuticals Inc: Research Funding. Maddocks:Celgene: Membership on an entity's Board of Directors or advisory committees; Teva: Membership on an entity's Board of Directors or advisory committees; Novartis: Research Funding; BMS: Research Funding; Merck: Research Funding; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees, Research Funding.

Beschreibung: Background: Patients with r/r tumor stage CTCL and/or PTCL have a poor prognosis. BV is currently FDA approved for CD30 positive CTCL and anaplastic large cell lymphoma (ALCL) with single agent activity in additional PTCL subtypes. Len also has single agent activity in patients with r/r CTCL/PTCL. The safety of the combination was established in a phase I trial in patients with r/r diffuse large B-cell lymphoma. Methods: We conducted a single-institution phase II trial to determine the safety and efficacy of BV+Len combination in patients with r/r CTCL/PTCL. Simon's 2-stage optimal design was followed to test the null hypothesis of overall response rate (ORR) ≤0.3 versus the alternative hypothesis of ORR≥0.5. Patients with ≥ 1 line of systemic therapy or 2 lines of skin directed therapy, at least stage IB (for CTCL), and no prior progression on BV were eligible regardless of CD30 staining. All patients were treated with BV 1.2 mg/kg IV and Len 20 mg PO daily q3 weeks for a maximum 16 cycles. After 7 patients were treated, we reduced Len to 10 mg given safety/tolerability concerns. Responses are assessed by the International Society for Cutaneous Lymphomas and the cutaneous lymphoma task force of the European Organization of Research and Treatment of Cancer (ISCL/EORTC) Global response criteria (for CTCL) and Cheson year criteria (for PTCL). The effect of treatment on quality of life is assessed by Skindex-16. Results: As of July 1, 2019, 17 subjects were treated; 10 (59%) with mycosis fungoides (MF), 2 (12%) with Sezary syndrome (SS), 2 (12%) with CD30+ lymphoproliferative disorder, and 3 (18%) with PTCL. Median age was 60 (49-90) years and 76% were males. CD30 was completely negative (50% reduction in their Skindex-16 scores after a median of 2 cycles (range 1-3). Conclusions: BV + Len is combination is safe and efficacious in a heavily pre-treated patients with T-cell lymphomas. Len doses higher than 10 mg daily are poorly tolerated and associated with excess tumor flare. Recruitment of both CTCL and PTCL patients for this trial is ongoing. Disclosures William: Guidepoint Global: Consultancy; Kyowa Kirin, Inc.: Consultancy; Defined Health: Consultancy; Techspert: Consultancy; Celgene Corporation: Consultancy. Brammer:Verastem, Inc: Research Funding; Viracta Therapeutics, Inc.: Research Funding; Bioniz Therapeutics, Inc.: Research Funding. Grantier:Pharmacyclics LLC and Janssen Oncology: Other: Advisory Board. Hoffman:Pharmacyclics LLC and Janssen Oncology: Other: Advisory Board. Baiocchi:Prelude: Consultancy. Epperla:Pharmacyclics: Honoraria; Verastem Oncology: Speakers Bureau. Christian:Triphase: Research Funding; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Research Funding; Immunomedics: Research Funding; Acerta: Research Funding; Genentech: Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Research Funding; Cephalon: Research Funding; Merck: Research Funding; Janssen: Research Funding; Millennium Pharmaceuticals Inc: Research Funding. Maddocks:BMS: Research Funding; Merck: Research Funding; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees; Teva: Membership on an entity's Board of Directors or advisory committees. OffLabel Disclosure: Brentuximab vedotin is being used off-label for CD30 negative peripheral and cutaneous T-cell lymphoma. Lenalidomide is being used off-label for both conditions (within a phase II clinical trial)

Beschreibung: Abstract 600 Mantle cell lymphoma (MCL) is an aggressive B-cell malignancy with a short median survival despite multimodal therapy. FTY720, an immunosuppressive drug approved for the treatment of multiple sclerosis, promotes MCL cell death via down-modulation of phospho-Akt and Cyclin D1, and subsequent cell cycle arrest (1). However, the mechanism of FTY720-mediated MCL cell death remains to be fully clarified. Here we show features of autophagy blockage by FTY720 treatment, including accumulation of autolysosomes, increased LC3-II and p62 levels. FTY720 is phosphorylated in vivo by sphingosine kinase 2 and converted to p-FTY720, which binds to sphingosine-1-phosphate (S1P) receptors. A non-phosphorylatable FTY720 derivative (OSU-2S) was recently developed at the Ohio State University (2): OSU-2S treatment induces MCL cell death and shows features of autophagy blockage that led us to conclude that FTY720 phosphorylation and its interaction with SP1 receptors are not required for FTY720-mediated cell death and blockage of autophagy in MCL cells. We also demonstrate that FTY720-induced cell death is mediated by lysosomal membrane permeabilization with subsequent translocation of lysosomal hydrolases to the cytosol. FTY720-mediated disruption of the autophagic-lysosomal pathway led to increased levels of CD74, a potential therapeutic target in MCL that is degraded in the lysosomal compartment. We have recently reported CD74 to be expressed on MCL cells and that milatuzumab (Immunomedics, Morris Plains, NJ), a humanized anti-CD74 monoclonal antibody, has significant anti-MCL activity in vitro and in vivo (3). This finding provided the rationale for examining combination therapy with FTY720 and milatuzumab. The in vitro survival of 4 MCL cell lines treated with FTY720, immobilized milatuzumab, and the combination was determined at 24 hours by Annexin-V/PI staining and flow cytometry. Incubation of 4 MCL cell lines with FTY720 and milatuzumab (1 μg/ml) resulted in a statistically significant decrease in cell viability compared to either agent alone for each of the four cell lines (P〈 0.01), despite using FTY720 at concentrations lower than the LC50 previously published [Jeko-1 FTY720: 10 μM (LC50: 12.5 μM), Z-138 and UPN-1: 6 μM (LC50: 7.5 μM); Mino 3.75 μM (LC50: 7.5μM)] (1). Notably, combination treatment resulted in synergistic killing in cell lines derived from patients with blastoid variant MCL (Jeko-1, Z-138, UPN-1), despite the fact that both FTY720 and milatuzumab as single agents showed only modest activity. Incubation of primary tumor cells from 6 MCL patients (3 blastoid variant and 3 classic MCL) with FTY720 (2.5 μM, LC50: 5 μM) and miltauzumab induced an average 78.5% cell death compared to 47% of FTY720 treated cells and 50% the milatuzumab-treated cells (P=0.0005 and P=0.0014, respectively). To examine the in vivo activity of FTY720 and milatuzumab, a preclinical model of human MCL using the SCID (CB17 scid/scid) mouse depleted of NK cells was used. In this model, i.v. injection of 40×106 JeKo cells results in disseminated MCL 3 weeks after engraftment. The primary end-point was survival, defined as the time to develop cachexia/wasting syndrome or hind limb paralysis. Mice (n=10/group) were treated starting at day 15 post engraftment. Twenty control mice received either placebo (saline) or trastuzumab (15 mg/kg) treatment. The third group was treated with FTY720 (5 mg/kg) every day for 2 weeks via i.p injection. The fourth group received milatuzumab (15 mg/kg) every three days, via i.p. injection. The fifth group received the combination of FTY720 and milatuzumab. The median survival for the combination-treated group was 36 days (95% CI:31,36), compared to 28 days for the saline-treated mice (95% CI:24,31), 27 days for the trastuzumab-treated mice (95% CI:23,29), 31 days for the FTY720-treated mice (95% CI:28,32), and 33.5 days for the milatuzumab-treated mice (95% CI:23,34). The combination treatment significantly prolonged survival of this group compared to control groups (P