Leleu, Xavier

e14640 Background: MicroRNAs (miRNAs) are non-coding RNAs that act as negative regulators of gene expression. They have been described to play roles in solid tumors and hematologic malignancies. However the role of miRNAs in multiple myeloma (MM) has not been yet fully described. Methods: We performed miRNA-profiling of primary bone marrow-derived CD138+ MM cells, compared to their normal cellular counterparts and validated data by qRT-PCR. In vitro and in vivo functional studies were performed on miRNA-15a- and -16–1-precursors-transfected MM cells. Effect of miRNA-15a and -16–1 on signaling cascades have been evaluated by western blot and immunofluorescence. NF-kB activity has been studied using the Active Motif TransAM kit. In vivo MM cell growth has been evaluated by either using an in vivo imaging model or bioluminescence. Angiogenesis has been studied both in vitro and in vivo using the chorioallantoic membrane model. Results: We identified a MM-specific miRNA signature characterized by down-expression of miRNA-15a, -16–1 and over-expression of miRNA-222/-221/-382/-181a/-181b (P<0.01). Data were confirmed by qRT-PCR on matched samples. Predicted targets for the decreased miRNAs in MM patients included pro-angiogenic cytokines, oncogenes, cell cycle regulators, NFkB activators. Conversely, predicted targets for the increased miRNAs included cell cycle inhibitors, suppressors of cytokine signaling, and pro-apoptotic factors. We demonstrated that miRNA-15a and - 16–1 regulate proliferation and growth of MM cells. Indeed, transfected cells showed decreased DNA synthesis; decreased cyclinD1/cyclinD3/CDC25a/pRb protein expression; phase G1 cell cycle arrest. Moreover, transfected cells showed inhibition of NFkB pathway as shown by reduced p65-/p50-/p52-NFkB activities; downregulation of p-p65/p50/p52 nuclear protein level; upregulation of cttosolic phospho-IkB; and inhibited translocation of p-p65 from the cytolplasm to the nucleus. Similarly, inhibition of MM cell growth was confirmed in vivo; and anti-angiogenic properties of miRNA-15a and -16–1 were demonstrated both in vitro and in vivo. Conclusions: These data indicate that miRNAs play a pivotal role in the biology of MM; providing the basis for the development of new miRNA-based targeted therapies in this disease. No significant financial relationships to disclose.

Abstract Waldenström’s macroglobulinemia (WM) is an incurable low-grade lymphoproliferative disorder characterized by bone marrow (BM) infiltration of a clonal population of small B-lymphocytes, plasmacytoid lymphocytes and plasma cells that secrete monoclonal IgM antibody. Because it is difficult to obtain tumor metaphases for karyotype studies, few recurrent chromosomal abnormalities have been reported and the genetic basis of the disease remains poorly defined. Therefore, we performed a comprehensive high-resolution study to identify genomic abnormalities involved in WM pathogenesis. Fifty-seven WM patients were analyzed using a combination of array-based comparative genomic hybridization (aCGH)(N=42); gene expression profiling (GEP)(N=22), DNA sequencing (N=24) and cIgM-FISH (N=57). Agilent 244A and Affymetrix U133 platforms were used in the aCGH and GEP experiments, respectively. An NF-κB index was calculated from GEP data, as a surrogate marker of NF-κB transcription activity. NFKB2 sub cellular localization was determined by immunofluorescence staining. Overall, 83% of samples have aCGH defined chromosomal abnormalities, with a median of 3 abnormalities per patient (range 0 to 27). We identified 16 recurrent regions of copy number change found in &gt;5% (3 or more patients); 10 deleted and 6 amplified regions. The most common abnormality was the entire or partial deletion of 6q, identified in 40% of cases. Four nonoverlapped minimal deleted regions were identified on 6q (MDR1 to MDR4), each of them being present in at least 14 of 17 patients with the abnormality. Gain of 6p was the second most common abnormality (17%) and its presence was always concomitant with 6q loss. Other recurrent deletions were 13q14 (10%) and 7q22, 8p, 11q22-q23, 11q23-q24 and 17p11-p13 (7% each). Copy gains were identified as partial or entire gains of chromosomes 18 (17%), 4 (12%) and 3 (10%), 8q (10%) and Xq27.1-q28 (10%). Three patients had either homozygous deletions or LOH with mutations affecting both alleles of TRAF3 on 14q32. TRAF3 inactivation was correlated with an increased NF-kB transcriptional signature and it was associated with activation of the non-canonical NFkB pathway. Additionally, we identified the inactivation of TNFAIP3, another negative regulator of the NF-kB pathways, in one of 24 patients. Finally, interstitial deletions identified in 4 patients at 13q14 identified a 1.1 Mb MDR, including MIRN15A and MIRN16-1. These findings confirm that focal 13q14 deletion is not restrict to B-CLL and that the MIRN15A/MIRN16-1 abnormalities might be common to several indolent B-cell diseases. Overall, we identified TRAF3 and TNFAIP3 inactivation in 5.3% and 2.4%, respectively. To our knowledge, this is the first study showing the inactivation of bona fide tumor suppressor genes in WM patients. Furthermore, these genes are negative regulators of NF-kB signaling pathway, highlighting its biologic importance in sustaining and limiting growth in WM. Mutational activation of this pathway, which is normally activated by ligand-receptor interactions within the BM microenvironment, suggest a therapeutic role for inhibitors of NF-KB pathway activation in the treatment of WM.

Abstract PURPOSE: Recent advances in understanding of the molecular alterations that occur at the genetic and epigenetic levels in Multiple Myeloma (MM) have led to major leaps in identifying molecular pathways that regulate progression and resistance to therapeutic agents. However, despite great scientific advances at the genomic level, studies to identify signaling pathways deregulated at the functional proteomic level in MM are limited. In this study, we used a rapid and reproducible antibody-based protein microarray technique to screen the functional differences between malignant plasma cells in samples obtained from patients with MM compared to normal plasma cells (NPC) from the bone marrow of healthy volunteers. METHODS: We determined the protein expression level of 512 polypeptides in 12 samples of newly diagnosed patients with MM using high-throughput proteomic analysis with antibody-based protein microarray. Primary CD138+ sorted MM cells were obtained from the bone marrow of patients after informed consent. MM1.S was used in this study. Using immunohistochemistry and immunoblotting were confirmed. Lentivirus was used to knockdown CRIK. Gene expression datasets from the Mayo Clinic (accession number GSE 6477) and the UAMS (accession number GSE 2658) were obtained from the Gene Expression Omnibus for analysis. The Mayo dataset was generated using Affymetrix U133A platform whereas the UAMS dataset was generated using Affymetrix U133plus 2.0 platform. RESULTS: We identified four subgroups of MM using unsupervised clustering analysis. We confirmed overexpression of some of these proteins including CRIK and CDK4 using immunohistochemistry and immunoblotting. Many of these proteins are known to be deregulated in MM, indicating that this technique can accurately identify proteins that are over or under-expressed in MM in a high-throughput fashion. In addition, we identified novel proteins that are not previously known to be differentially expressed in MM, including the small GTPase member of the Rho family, CRIK protein. We then showed using knockdown of CRIK that this novel protein specifically regulates migration and adhesion in MM. There was no effect on survival of MM cells using the CRIK knockdown. Analyzing the GEP data of the 15 NPC, 46 monoclonal gammopathy of undetermined significance (MGUS) or smoldering myeloma (SMM) and 101 MM samples from the Mayo Clinic, there was a significant increase in expression of CIT from NPC to MM. Among the 351 patients entered into TTII trials from UAMS, CIT expression was similar across the different TC class. Using a cut-off normalized expression level of 1.25 (a level above expression in NPC), MM with a high CIT expression (n=81) had a significantly shorter survival than the other patients. CONCLUSION: In this study, we show that MM cells express a high level of CRIK, and that inhibition of this protein leads to significant inhibition of adhesion and migration of MM cells. In addition, CRIK protein expression correlated with CIT gene expression, with high expression in MM samples compared to NPC. In addition, high CIT expression correlated with poor survival in patients with MM.

8035 Background: D-Rd significantly reduced the risk of progression/death by 44% in transplant-ineligible NDMM pts vs Rd in the phase 3 MAIA study. To examine the impact of age on efficacy/safety of D-Rd vs Rd in this population, a subgroup analysis was conducted in pts <75 and ≥75 y of age. Methods: Transplant-ineligible NDMM pts were randomized 1:1 to Rd ± DARA; stratification was based on age (<75 vs ≥75 y), ISS (I, II, III), and region (North America vs Other). Pts received 28-day cycles of either R 25 or 10 mg (based on renal function) PO QD on Days 1-21 and either d 40 or 20 mg (based on age or BMI) PO/IV weekly until progression. In the D-Rd arm, pts received daratumumab 16 mg/kg IV QW for Cycles 1-2, Q2W for Cycles 3-6, and Q4W thereafter until progression. PFS is the primary endpoint. Results: Among 737 randomized pts (D-Rd, n=368; Rd, n=369), 321 (44%) were ≥75 y of age. For D-Rd vs Rd, relative median dose intensity for R was 79% vs 93% for <75 y subgroup and 66% vs 89% for ≥75 y subgroup, respectively. After median follow-up of 28 mo, significant PFS benefit of D-Rd vs Rd was maintained in both <75 and ≥75 y subgroups (Table). Deeper responses and MRD-negative rate (10-5 threshold) remained higher with D-Rd vs Rd in both subgroups (Table). Most common (≥10%; D-Rd/Rd) grade 3/4 TEAEs in ≥75 y pts were neutropenia (60%/41%), lymphopenia (19%/12%), anemia (16%/22%), pneumonia (15%/10%), leukopenia (12%/6%), and thrombocytopenia (8%/11%). Fewer pts receiving D-Rd vs Rd discontinued treatment due to TEAEs (<75 y: 5% vs 12%; ≥75 y: 10% vs 21%). Conclusions: D-Rd pts received less R vs Rd group regardless of age. Efficacy of D-Rd in <75 and ≥75 y pts was consistent with the ITT population, and D-Rd demonstrated acceptable tolerability regardless of age. Together with the phase 3 ALCYONE study, these studies confirm clinical benefit of daratumumab plus standard-of-care in transplant-ineligible NDMM pts ≥75 y of age. Clinical trial information: NCT02252172. [Table: see text]

8004 Background: The primary objective of this phase 3 trial was to demonstrate progression free survival (PFS) improvement of isatuximab (Isa), a novel anti-CD38 monoclonal antibody, combined with pomalidomide (P)/dexamethasone (d) versus (vs) Pd. Methods: Patients (pts) with RRMM who received ≥2 prior lines, including lenalidomide (len) and a proteasome inhibitor (PI), refractory to last therapy were enrolled. IsaPd arm received Isa 10 mg/kg IV weekly for first 4 weeks (wks), then every 2 wks. Both arms received approved schedules of pom and dex (4mg PO days 1-21; 40mg [20mg if >75 yrs] PO or IV weekly) every 28 days until progression or unacceptable toxicity. Results: 307 pts (154 IsaPd, 153 Pd) were randomized and analyzed (ITT). Patient characteristics were well balanced across arms. Median age: 67 (36-86) yrs; median prior lines of therapy: 3 (2-11); estimated GFR: <60ml/min in 33.9% pts; 92.5% refractory to len, 75.9% to PI; and 19.5% pts had high-risk cytogenetics. At median follow-up of 11.6 months (mos), median PFS was 11.5 mos IsaPd vs 6.5 mos Pd; HR 0.596 (95% CI 0.44-0.81), P=0.001. PFS benefit was consistent across all major subgroups. ORR (≥PR) was 60.4% IsaPd vs 35.3% Pd, P<0.0001. VGPR rate or better was 31.8% IsaPd vs 8.5% Pd, and MRD negativity (NGS, 10-5) was seen in 5.2% IsaPd pts vs 0% Pd. At analysis date, overall survival (OS) was immature (99 events) but a trend to OS improvement in IsaPd (vs Pd) was observed (HR 0.687; 95% CI 0.461-1.023). Median treatment duration was 41 wks IsaPd vs 24 wks Pd; median Isa infusion (inf.) duration was 3.3h at 1st inf. and 2.8h at subsequent inf. Grade ≥3 AEs were observed in 86.8% IsaPd vs 70.5% Pd; 7.2% IsaPd and 12.8% Pd pts discontinued due to AEs; 7.9% IsaPd and 9.4% Pd pts died due to AEs. Inf. reactions were reported in 38.2% (2.6% grade 3-4) IsaPd. Grade ≥3 infections were seen in 42.8% IsaPd and 30.2% Pd, grade ≥3 neutropenia in 84.9% (febrile 11.8%) IsaPd and 70.1% (febrile 2.0%) Pd. Conclusions: IsaPd significantly improved PFS and ORR vs Pd, with a manageable safety profile. IsaPd is an important new treatment option for the management of RRMM. Clinical trial information: NCT02990338.

8095 Background: Multiple myeloma (MM) remains incurable and invariably relapses after initial therapy. There is no uniform approach to management of relapsed MM and is dictated by type of initial therapy and the response seen, and availability of new drugs. The outcomes associated with current approaches have not been systematically examined. Methods: We enrolled 383 patients (pts) with myeloma who had a documented relapse between Jan 2007 and June 2010, including 220 from Europe, 106 from Asia, and 31 from South America and 26 from North America. Time Zero (T0) was defined as date of treatment after first relapse. Results: Across the study, 61% were male and 49% were over 65 years at T0. ISS stage distribution at diagnosis included 26, 40 and 33% of patients in stages 1, 2 and 3, respectively. Among regimens used at first relapse; bortezomib (Btz) containing regimens were most common (54%), followed by lenalidomide (Len, 25%) and cyclophosphamide (21%). The overall response rate (>=PR) to first therapy after relapse was 58% including 14% with a CR. There was a progressive decrease in the response rates with successive regimen; 45%, 30% and 15% for regimens 2, 3 and 4 respectively. Len use was considerably lower in the Asian cohort, while Btz use was comparable across the regions. The median PFS from T0 was 13 mos and OS was 35 mos, for the entire cohort. The PFS to first salvage regimen was similar across the regions, while OS was shorter for the Asian and South American cohorts. In a univariate analysis, ISS stage 3, presence of cytogenetic abnormalities, history of plasma cell leukemia or extramedullary disease (EMD), bone marrow PC% > 33% and presence of renal insufficiency were all associated with a shorter PFS as well as shorter OS (P<=0.01). In a multivariate model, ISS stage 3 and presence of EMD were most associated with short OS. Conclusions: Median PFS for current second line regimens, typically containing Btz or Len appear to be 1 yr with an OS from first relapse of about 3 yrs. The OS from first relapse is nearly double that seen in a cohort of patients in first relapse prior to introduction of new drugs. Clear-cut regional differences can be seen in terms of patterns of drug use and likely reflect drug availability and healthcare costs.

Abstract INTRODUCTION: mTOR inhibitors have been associated with responses in Mantle cell lymphoma and other lymphomas (J Clin Oncol23; 5347, 2005). Phase I and II trials with the oral everolimus (RAD001, Novartis Pharmaceuticals) have demonstrated a favorable side effect profile. This phase II study tested everolimus in patients with relapsed/refractory Waldenstrom Macroglobulinemia (WM). METHODS: Patients who had at least one previous therapy for WM and who had relapsed or refractory disease were eligible. Other eligibility criteria included symptomatic disease, > 2 weeks from last therapeutic agent used, >10% involvement with lymphoplasmacytic cells in the bone marrow, IgM paraprotein > 2x upper limit of normal, absolute neutrophil count >1000/mm3 and platelet count >75,000/mm3, serum creatinine of < 2 x upper limit of normal. NCI CTCAE v3.0 was used for toxicity assessment. Response was assessed by criteria established at the second consensus panel for WM. All patients received 10mg RAD001 daily for 28 days per cycle for 6 cycles; response was assessed after 2 cycles. RESULTS: 10pts (8 men and 2 women, median age is 62 years, range 52–71) have been treated to date. The median number of lines of prior treatment was 3 (range 1 – 5). The median IgM at baseline was 3970 mg/dL (range 3120– 7410); median M-spike at baseline was 2.07 gm/dL (range 1.41 – 4.02); and median hemoglobin was 11.3 g/dL (9.4–13.3). The median follow up was 4 months (range 1 – 7 months). Prior therapy included rituximab, nucleoside analogues (fludarabine and 2-CDA), combination chemotherapy (e.g CHOP, CVP), chlorambucil. and bortezomib. Seven patients are currently evaluable for response. The best response to single agent RAD001 after 2 cycles is presented in Table 1. Median duration of response has not been reached. Patients tolerated RAD001 well without significant toxicities. The main toxicities observed were apthous ulcers in 4 patients. One patient required dose reduction due to mucositis. One patient stopped therapy within the first month of treatment and went on to hospice care before succumbing to his disease after one month. Attributable toxicities otherwise proved manageable with appropriate supportive care and RAD001 was generally well tolerated, with no peripheral neuropathy. CONCLUSIONS: Oral RAD001 as monotherapy has been well tolerated and demonstrates exciting activity achieving PR + MR in 57%, and/or stabilization of disease in 43% of evaluable patients with relapsed WM. Accrual of a total of 30 patients is rapidly ongoing. Updated data will be presented at the meeting. Table 1 Response N=7; ORR (CR+PR+MR)= 57% Median time to best response (months) Partial Response 1 (14%) 5 Minimal Response 3 (43%) 4 (3–6) Stable Disease (SD) 3 (43%) NA Progressive Disease 0

Abstract Background: The initial therapies for multiple myeloma have changed significantly in the recent years with routine incorporation of combinations containing IMiDs and proteasome inhibitors. However, patients with MM invariably relapse after their initial treatment and undergo successive therapies for continued control of their disease. The increasing access to new therapies for treatment of relapsed disease has led to improved survival of patients with MM. Many recent phase 3 trials have studied the impact of new agents on outcome of patients with MM who are relapsing after the initial lines of therapy for relapsed disease. However, the natural history of relapsed myeloma earlier in the course of relapsed disease has not been studied in detail. Patients and methods: We designed a global, multicenter, retrospective study to examine the current treatment approaches for initial relapses in MM and patient outcomes following application of successive treatment regimens. Patients with multiple myeloma who experience a first relapse between January 1, 2007 and December 31, 2011 were identified at participating sites. Clinical and laboratory data pertaining to the time of diagnosis and from the time of individual relapses up to and including the third relapse will be obtained from the clinical records. The first date of treatment with an anti-myeloma regimen for first disease relapse was termed time zero (T0). Results: Three hundred and fifteen patients were enrolled; median age at diagnosis was 59 years (range: 35 - 86), 59% were male. Patients were enrolled from North America (33%), Europe (35%) or Asia (32%). The patients were diagnosed between 1997 and 2011 and the median time to T0 from diagnosis was 23.9 months (range: 0.8 - 131.9 months). An IMiD (thalidomide or lenalidomide), bortezomib or alkylator (melphalan or cyclophosphamide) was part of the initial therapy in 63%, 36% and 51% of patients, respectively; 93 (33%) patients had stem cell transplantation as part of initial treatment. The median follow up from the study entry was 56 months; 117 were alive at the time of data extraction. A second line, third line and fourth line of treatment were recorded in 307, 163 and 84 patients respectively. An IMiD (thalidomide, lenalidomide, or pomalidomide), proteasome inhibitor (bortezomib or carfilzomib) or alkylator (melphalan or cyclophosphamide) was part of the therapy for first relapse in 50%, 59% and 33% of patients, respectively. The responses to the regimens after T0, the TTNT, PFS and OS to each line of therapy are provided in the Table. Conclusion: The current study provides an assessment of the current treatment approaches used for initial treatment of MM and the salvage treatment options utilized. The study again demonstrates the progressively shorter duration of disease control with each successive treatment regimen, reflecting ongoing development of drug resistance. The overall survival of over 3 years from the time of therapy for first relapse highlights the impact of the newer therapies that have been introduced for this disease. Table. Treatment outcomes after initial relapse Endpoint 2nd line therapyN=307 3rd line therapyN=163 4th line therapyN=84 Partial response or better Median in Months (95% Confidence Interval) Overall Survival 36.1 (30.2, 42.4) 18.4 (14.5, 26.8) 12.6 (10.4, 19.0) Progression-Free Survival 13.4 (11.8, 15.8) 8.3 (6.5, 11.2) 6.4 (5.0, 8.1) Time to Next Treatment 15 (12,17) 9.8 (7.4, 12.0) 6.6 (5.8, 8.7) Figure 1. Figure 1. Disclosures Kumar: Onyx: Consultancy, Research Funding; Skyline: Consultancy, Honoraria; BMS: Consultancy; Sanofi: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Novartis: Research Funding; Takeda: Consultancy, Research Funding; Celgene: Consultancy, Research Funding. Dimopoulos:Novartis: Honoraria; Amgen: Honoraria; Janssen-Cilag: Honoraria; Genesis: Honoraria; Janssen: Honoraria; Onyx: Honoraria; Celgene: Honoraria. Leleu:Janssen: Honoraria; Celgene: Honoraria; Takeda: Honoraria; Amgen: Honoraria; TEVA: Honoraria; Novartis: Honoraria; BMS: Honoraria; Pierre Fabre: Honoraria; LeoPharma: Honoraria; Chugai: Honoraria. Moreau:Celgene, Janssen, Takeda, Novartis, Amgen: Membership on an entity's Board of Directors or advisory committees. Lahuerta:Janssen Cilag, Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees. Vij:Takeda, Onyx: Research Funding; Celgene, Onyx, Takeda, Novartis, BMS, Sanofi, Janssen, Merck: Consultancy.

Abstract Abstract 3989 Background: Treatment patterns of multiple myeloma (MM) vary across the globe, mostly dictated by the availability and patient access to different drug therapies. The outcomes of patients with MM, especially relapsed myeloma can be significantly affected by the availability of newer treatments, as well as potential biological differences related to ethnicity. We have previously shown that the outcome of patients relapsing after therapy with bortezomib (Bz) and one or more of the IMiDs remain poor with the currently available treatments and represent a difficult group of patients to treat. We undertook the current analysis on a set of patients from United States, several European countries and South Korea. Methods: We designed a multicenter, retrospective study that enrolled 294 patients with relapsed MM, from 14 sites (122 from Europe, 107 from US, and 65 from Korea). Patients were refractory to Bz, defined as no response to prior Bz-containing regimen or disease progression within 60 days of a Bz-containing regimen. Patients were also relapsed, refractory, intolerant, and/or ineligible, to treatment with an IMiD (thalidomide or lenalidomide). The date patients satisfied the above entry criteria was defined as time zero (T0). Clinical and laboratory data from diagnosis and individual relapses were collected along with details of all MM drug therapies before and after T0. Responses were assessed by IMWG or EBMT criteria. The goal of the study was to compare the characteristics of patients who satisfy the above inclusion criteria, the therapies employed prior to and after T0 and clinical outcome among these patients from different parts of the world. Results: The mean (median, range) time to reaching T0 from diagnosis was 4.5 (4.0, 12.8), 4.2 (3.2, 18.6), and 3.2 (2.8, 9.6) years from diagnosis for patients from US, Europe and Korea, respectively, P=0.021. The mean (median, range) number of therapies for the three groups were 8 (8, 13), 4 (4, 10), 5 (4, 7), respectively; P<0.001. The response rates (>=PR) to the initial therapy at diagnosis were 56%, 77% and 49% respectively for the US, European and Korean cohorts. Overall 220 patients had at least one therapy after T0, and 114 (52%) had a novel agent (Bz, len or thal) containing regimen as their first treatment after T0. Patients in US were more likely to receive additional therapies after the first post-T0 therapy; 62%, 32%, and 12% of patients from US, Europe and Korea, respectively, began a second post-T0 regimen within 2 years following time zero. The median number of therapies post T0 was 2, 1, and 1 for patients in US, Europe and Korea respectively. The response rates to the first regimen after T0 were 15%, 33% and 19% for the US, European and Korean cohorts, and were similar between those receiving a regimen with one of the novel drugs compared to rest. Patients younger than 60 years and those with prior transplants were more likely to respond to post T0 regimens. The median time to progression or death from T0was similar for the three patient cohorts, 5 months (Figure 1A). The median overall survival (95% CI) from T0 was 13 months (10, 16), 7 (5,9) and 8 (4,9) respectively for the US, European and Korean cohorts (Figure 1B). Conventional prognostic factors, especially the ISS stage was predictive of OS post T0. Additionally, presence of extramedullary disease was associated with a shorter overall survival. Conclusion: The results of the current study demonstrate significant differences between different parts of the world in terms of the treatment patterns both in the setting of initial therapy as well as treatment of relapsed disease. Patients in the US were more likely to receive multiple regimens both before and after T0. This is likely a reflection of increasing numbers of new drugs that have gone into clinical trials and thus enhancing options. The study further highlights the poor outcome of patients who have relapsed after the new drugs, irrespective of the geographical location. Disclosures: Kumar: Merck: Consultancy, Honoraria; Genzyme: Consultancy; Celgene: Consultancy. Richardson:Millennium: ; Celgene: ; Johnson & Johnson: ; Novartis: ; Bristol Myers Squibb:. Moreau:Millennium Pharmaceuticals, Inc.: Advisory board, Honoraria; Janssen: Advisory board, Honoraria. Sonneveld:Millennium Pharmaceuticals, Inc.: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Onyx: Membership on an entity's Board of Directors or advisory committees, Research Funding. Siegel:Merck: Honoraria; Millenium: Honoraria, Research Funding, Speakers Bureau. San Miguel:Janssen-Cilag: Honoraria; Celgene: Honoraria. Palumbo:celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees. Durie:Celgene: Membership on an entity's Board of Directors or advisory committees.

Abstract Abstract 1876 Poster Board I-901 Background: Multiple Myeloma (MM) remains incurable in spite of new effective agents and combination regimens. SRC family kinases (SFK) are potential targets for therapy in MM: Hck, Fyn and Lyn are implicated in IL6-induced proliferation. Dasatinib is a potent inhibitor of not only BCR-ABL, but also SFK, c-KIT, PDGFRb, and EPHA. In myeloma and endothelial cells (ECs) isolated from MM patients (pts), dasatinib blocked proliferation, survival, adhesion, migration, and angiogenic potential, through a combined targeting of PDGFRβ as well as VEGF-triggered phosphorylation of SRC. Lenalidomide has clinical efficacy in the treatment of multiple myeloma (MM) as a single agent and in combination with dexamethasone. The combination of dasatinib, lenalidomide and dexamethasone exhibits synergistic inhibition of MMIS cells. Methods: The primary objective of this Phase I, multicenter, open-label, non-randomized study was to determine the maximum tolerated dose (MTD) of the combination of dasatinib, with lenalidomide and dexamethasone in pts with relapsed or refractory (RR) MM. Secondary objectives were to assess the tolerability of the combination, to establish the dose for future clinical investigations, and to assess the efficacy by International Uniform Response and EBMT Criteria. Pts ≥18 years with confirmed RR MM, measurable disease (at least 1 g/dL for IgG or 0.5 g/dL for IgA in serum or urinary excretion of 200 mg monoclonal light chain/24 hours), and at least one prior treatment were enrolled sequentially into increasing dose cohorts (using a 3+3 design). Pts received oral dasatinib daily on a continuous schedule, oral lenalidomide daily for 21 days, and oral dexamethasone 40 mg/day (Days 1, 8, 15, and 22). Cycles were repeated every 28 days. Dose-limiting toxicities (DLTs) were assessed in the first cycle. If there was no DLT, dose escalation continued to MTD, followed by an expansion phase of the established dose. Results: Enrollment is ongoing. 16 pts (6 M, 10 F; median age 70.5 years, range 51–80) were treated in cohorts 1, 2, 3 and 4; MTD has not been established (as by July 2009). The median number of prior lines of therapy was 3 (range 1–6). Seven pts had prior autologous stem cell transplantation; 8 pts had prior thalidomide, 4 prior lenalidomide and 3 pts both. Baseline β2 microglobulin levels of >3.5mg/L were reported in 4 pts. The most common (310%) treatment related adverse events (AEs) diarrhea 6 (38%); nausea 4 (25%); constipation 2 (13%); stomatitis 2 (13%); asthenia 3 (19%); weight decrease 5 (31%); dyspnea 2 (13%); rash 2 (13%); vertigo 2 (13%); insomnia 2 (13%). The most common grade 3 / 4 hematologic AEs included neutropenia 6 (38%), anemia 4 (25%) and thrombocytopenia 3 (19%). Two DLTs were identified in cohorts 1 and 4: 1 pt had 2 point decline in ECOG Performance Status and other pt had a drug interruption > 15 days due to nausea and vomiting, respectively. Six out of 16 pts discontinued treatment: 1 due to death in first cycle (D19); 3 for AEs (2 study drug related and 1 unrelated), 1 withdrawal of consent, 1 following maximal clinical benefit (minor response) after 12+ cycles. As of July 2009, 10 pts remain on treatment, with a median duration of treatment of 4.2 months (range 0.6–12). Responses were observed in 13 pts: 8 partial responses (PR), and 5 minor responses (MR). 1 pt had stable disease (SD) and 2 pts were not evaluable (1 pts died before completion of cycle 1 and other pt was too early for assessment). Conclusion: Dasatinib in combination with lenalidomide and dexamethasone is well tolerated and preliminary activity has been observed. Disclosures: Facon: Celgene: Membership on an entity's Board of Directors or advisory committees; Janssen Cilag: Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees. Stewart:Takeda-Millenium, Celgene, Novartis, Amgen: Consultancy; Takeda, Millenium: Research Funding; Genzyme, Celgene, Millenium, Proteolix: Honoraria. Garzon:BMS: Employment. Bleickardt:BMS: Employment. Gialelis:BMS: Employment. Tuozzoli:BMS: Employment. Derreumaux:BMS: Employment. Sonneveld:Janssen-Cilag: Honoraria.