Reeder, Craig B.

Abstract Background Bendamustine/rituximab (BR) and dexamethasone/rituximab/cyclophosphamide (DRC) combination therapy are acceptable options for the treatment of WM, both in the frontline or salvage setting. Prospective data, however, are only available in treatment-naïve (TN) WM patients, and no direct comparison between BR and DRC has been reported. We compared outcomes of BR and DRC in relapsed/refractory (R/R) and TN WM patients seen at a single institution. Methods Records of WM patients seen consecutively at Mayo Clinic from 01/2007 to 12/2014 were reviewed. The MYD88L265P status, as assessed by AS-PCR, was recorded when available. The data obtained from symptomatic patients treated with DRC or BR were analyzed. The time-to-event analyses were performed from DRC or BR therapy using the Kaplan-Meier method. We used the Consensus criteria (6th International Workshop) for response assessment. Results Of 160 WM patients, 60 patients received BR (73% in R/R setting) and 100 patients received DRC (50% in R/R setting). In the R/R population, BR was the 2nd line (range 2-11) therapy in 47% of patients, while DRC was 2nd line (range 2-8) in 58% of patients. Rituximab monotherapy was the only prior line of therapy in 8 (20%) patients in the BR group and 20 (40%) in the DRC group (p=0.66). Baseline characteristics were similar in patients treated with BR or DRC (Table 1). Six patients received both BR and DRC during their disease course and overlapped between the 2 cohorts. Among the previous untreated patients, the median IgM levels decreased from 3,785 mg/dL to 724 mg/dL (p=0.0001) at best response with BR, while it decreased from 4,130 mg/dL to 1,250 mg/dL (p=0.001) with DRC. The median time to best response was 6.1 (1-25) months in the BR group and 11 (0.5-47) months in the DRC group (p=0.13). For patients treated with BR, the overall response rate (ORR) was 93% [VGPR 29% (n=4), PR 57% (n=8), MR 7% (n=1)]. One patient (7%) had progressive disease. For patients treated with DRC, ORR was 96% [VGPR 17% (n=8), PR 70% (n=32), MR 9% (n=4)]. One patient (4%) achieved SD. Median follow up in the BR and DRC groups were similar (30 months). The 2-year progression-free survival (PFS) was 88% and 61% in the BR and DRC groups, respectively (p=0.08). The 2-year time-to-next therapy (TTNT) was 88% and 76% in the BR and DRC groups, respectively (p=0.35). Median PFS, TTNT and disease specific survival (DSS) were not reached with either regimen. In the R/R setting, the median IgM levels decreased from 3,880 mg/dL to 659 mg/dL (p=0.0001) at best response with BR, and from 3,870 mg/dL to 1,846 mg/dL (p=0.001) with DRC. The median time to best response was similar [7 (1-39) months with BR and 7 (0.5-28) months with DRC (p=0.77)]. For patients treated with BR, ORR was 95% [CR 3% (n=1), VGPR 38% (n=14), PR 41% (n=15), MR 13% (n=5)]. Two patients (5%) had progressive disease. With DRC, the ORR was 87% [VGPR 4% (n=2), PR 64% (n=30), MR 19% (n=9)]. Four patients (9%) achieved SD and 2 patients (4%) had progressive disease. Median follow up from BR was 32 months and 51 months from DRC (p=0.24). The 2-year PFS was 66% and 53% in the BR and DRC groups, respectively (p=0.08). The 2-year TTNT was 75% and 68% in the BR and DRC groups, respectively (p=0.24). The median DSS in the BR group was 69 months (95% CI: 65-69) and NR (95% CI: NR-NR) in the DRC group (p=0.57). The proportion of patients with R/R disease was significantly higher in the BR cohort (Table 1). In a bivariate analysis of the entire cohort for PFS, incorporating the setting (TN vs. RR) and the regimen involved (BR vs. DRC), the latter emerged as a significant factor (hazard ratio 0.52, p=0.019) in favor of BR. Time-to-event outcomes and response rates were similar in the MYD88L265P and MYD88WT patients. Grade ≥ 3 adverse events were neutropenia (12%), infections (7%) and nausea/vomiting (2%) with BR, and neutropenia (20%), thrombocytopenia (7%) and infections (3%) with DRC. Conclusions Although both DRC and BR regimens show activity and comparable toxicities, BR regimen shows a trend for superior PFS in WM patients, both in the TN and R/R setting. No difference was seen in TTNT. MYD88 L265P mutation status does not appear to impact activity of BR or DRC. Randomized controlled trial(s) are needed to confirm our findings. Disclosures Ailawadhi: Pharmacyclics: Consultancy; Novartis: Consultancy; Amgen Inc: Consultancy; Takeda Oncology: Consultancy. Ansell:BMS, Seattle Genetics, Merck, Celldex and Affimed: Research Funding. Reeder:Millennium: Research Funding; BMS: Research Funding; Novartis: Research Funding; Celgene: Research Funding. Dispenzieri:Jannsen: Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; pfizer: Research Funding; Prothena: Membership on an entity's Board of Directors or advisory committees; Celgene: Research Funding; Alnylam: Research Funding; GSK: Membership on an entity's Board of Directors or advisory committees. Kumar:Sanofi: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; AbbVie: Research Funding; Array BioPharma: Consultancy, Research Funding; BMS: Consultancy; Kesios: Consultancy; Glycomimetics: Consultancy; Skyline: Honoraria, Membership on an entity's Board of Directors or advisory committees; Noxxon Pharma: Consultancy, Research Funding; Millennium: Consultancy, Research Funding; Onyx: Consultancy, Research Funding; Celgene: Consultancy, Research Funding. Kapoor:Celgene: Research Funding; Takeda: Research Funding; Amgen: Research Funding.

Abstract Background: Ixazomib is an experimental, orally bioavailable, proteasome inhibitor that has demonstrated anti-tumor activity in relapsed multiple myeloma (MM). In the dose escalation studies, ixazomib was tolerated up to a dose of 5.5 mg given every week as a single agent, while a dose of 4 mg was utilized in the combination studies with lenalidomide. We undertook this study to examine the efficacy and tolerability of the two doses of ixazomib in combination with dexamethasone in patients with relapsed MM. Patients and methods: This was a randomized phase 2 study of two doses of ixazomib (4mg; Arm A or 5.5 mg; Arm B) given weekly for three weeks with a week off along with weekly dexamethasone (40 mg) in patients with relapsed MM, who are proteasome inhibitor na•ve (including bortezomib) or have received less than 6 cycles of therapy with bortezomib and had a PR or better with no progression at the time of discontinuation. The primary objective was to determine the confirmed overall response rate (>=PR); secondary objectives included progression free and overall survival. A total of 71 patients were accrued from February 2013 to April 2015; one patient was ineligible. Results: Baseline characteristics were similar in the two arms; median age across the study was 70 years (46-84); 53% were male. Median number of prior therapies was 4 (range 2-6); 90% of the patients had prior IMiDs, 70% had prior transplant and 29% had prior bortezomib. At a median follow up of 10 months, 17 (49%) and 19 (54%) of patients had disease progression in arms A and B respectively with 12 (34%) patients in each arm still continuing on treatment. All patients in each arm were evaluable for response; the overall response rates were 31% in arm A (95%CI: 17-49) and 51% (95%CI: 34-69) in Arm B. The depth of response, event free survival and overall survival are outlined in Table 1. Among the patients with no prior bortezomib exposure the response rates were 38% for Arm A and 52% for Arm B. The treatment was well tolerated with 2 patients in each arm discontinuing treatment for adverse events; there were no on study deaths. A grade 3 or higher AE that was at least possibly related to treatment was seen in 21% and 54% in Arms A and B respectively; with 15% and 37% hematologic and 6% and 29% non-hematologic AEs. The most common attributable toxicities encountered included fatigue, thrombocytopenia, diarrhea and nausea with more grade 3 toxicities among Arm B. Peripheral neuropathy, possibly related to ixazomib, was seen in 55% (only grade 1 or 2) in arm A and 43% (2 patients with grade 3) in Arm B. Toxicities led to dose reduction of ixazomib in 17% and 43% of patients in Arm A and B respectively; the median number of cycles administered were 5 (1-24) and 5 (1-22) respectively. Conclusions: Ixazomib in combination with dexamethasone was well tolerated with significant anti-myeloma activity in this group of patients with relapsed MM. Deep responses including stringent CR were observed. The higher dose of ixazomib appears to be associated with a higher response rate but with higher rate of adverse events requiring dose reductions. Table 1. Treatment outcome in all patients Arm B (4 mg) (N=35) Arm C (5.5 mg) (N=35) Response Rate 31% (95%CI: 17-49) 51% (95%CI: 34-69) No. of Responders 11 18 sCR 0 1 CR 1 0 VGPR 7 8 PR 3 9 MR 5 1 Median Overall Survival1 NA NA 6 Months 100% 100% Median Event Free Survival1,2 8.4 mos (95%CI: 4.3-13.2) 8.2 mos (95%CI: 3.8-16.3) %Event Free at 6 Months 60% (95%CI: 45-81) 60% (95%CI: 45-81) Median Duration of Response1 16.7 mos (95%CI: 9.3-22.0) 16.3 mos (95%CI: 7.0-20.1) Median Time to Response 1.1 mos (range: 0.8-3.6) 1.0 mos (range: 0.8-7.5) CI: confidence interval; mo: month; NA: not attained 1Kaplan Meier 2Event-free survival time is defined as the time from registration to the first of disease progression, death due to any cause, or subsequent treatment for multiple myeloma. Disclosures Kumar: Celgene: Consultancy, Research Funding; Sanofi: Consultancy, Research Funding; Skyline: Consultancy, Honoraria; Onyx: Consultancy, Research Funding; Novartis: Research Funding; Janssen: Consultancy, Research Funding; Takeda: Consultancy, Research Funding; BMS: Consultancy.

Abstract Introduction: Most myelofibrosis (MF) patients develop anemia during evolution of the disease process predicting decreased survival. Previous studies exploring the effect of danazol for the treatment of anemia in MF demonstrate responses in anemia. In prior randomized-controlled studies, ruxolitinib demonstrated improvements in splenomegaly, symptom burden, and even survival yet improvements in cytopenias were uncommon. We designed a phase II multicenter pilot study to evaluate the efficacy and tolerability of combination therapy with ruxolitinib and danazol in MF patients with anemia. Methods: This was a Simon optimum two-stage phase II trial. Eligible subjects received ruxolitinib, a JAK 1/JAK2 inhibitor, at 10mg (plat >75 x10x9) BID or 5mg (plat <75 x10 x9) BID) representing initial dose reduction for JAK inhibitor naïve patients to minimize cytopenias, in combination with tapered danazol up to 200mg orally TID. Dose escalation was allowed after completion of 28 days for lack of response or for disease progression. Pts without progression continued for 6 cycles at 56 days each. Treatment modifications were allowed for either medication based on emergent adverse events (AE). Treatment responses were evaluated every cycle by IWG-MRT criteria (Blood 2006). Patient reported outcome questionnaires (MPN-SAF, EORTC QLQ-C30) were administered at baseline, prior to treatment cycles, and at study discontinuation. Results: Patients: Fourteen pts enrolled (9 Mayo Arizona, 5 Mount Sinai). Median (Med) age 70.5 (range 43-78), M:F ratio 1.8:1. Ten primary MF, 2 post-essential thrombocythemia MF, and 2 post-polycythemia vera MF. JAK2 V617F positive in 42.9%. DIPSS Low in 1 pt, Int-1 in 1pt, Int-2 in 8 pts, High in 2 pts, and unknown in 2pts. Transfusion dependence in 35.7% at baseline. Med baseline hemoglobin (hgb) was 9.0 g/dL (R: 8.3 - 12.4), platelet (plt)157 x109/L (R:143 - 520). Thirteen pts received prior therapy, with 9 pts (64.2%) on a JAK inhibitor within 3 months of study entry. Tolerability: Nine pts (64.2%) ended active treatment, due to progression of disease in 2 pts (22.2%), adverse event (AE) in 2, pt preference in 2, stem cell transplant in 1, unrelated death in 1, and comorbidity in 1. Med duration of therapy: 91 days (range 24-287). AEs regardless of attrition included: hematologic grade 3 or >: anemia in 7 pts (50%), neutropenia in 2 (14.3%), leukopenia in 1 (7.1%), and thrombocytopenia in 2 (14.3%). Non-hematologic grade 3 or >: electrolyte abnormalities in 3 pts (21.4%), infection in 2 (14.3%), edema in 1(7.1%), hypertension in 1 (7.1%), and intracranial hemorrhage in 1 (7.1%). Efficacy: Of the 5 JAK inhibitor naïve pts, 4 had stable or increasing hgb levels with therapy despite new ruxolitinib therapy. Of the 9 pts on prior JAK inhibitor (5 ruxolitinib, 4 other), 5 (55.5%) and 7 (77.7%) patients had stable or increasing hgb or plt levels, respectively. See Table #1. Four pts (28.6%) had at least 50% improvement from baseline on MPN-SAF TSS (95% CI 8.4%-58.1%). Overall treatment response: (IWG-MRT) stable disease (SD) in 10 pts (71.4%), clinical improvement (CI) in 3 (21.4%) all of which were spleen responses, and progressive disease (PD) in 1 (7.1%). Trial was halted secondary to lack of anemia response. Table 1. Patient Specific Response Patient IWG-MRT Response: Study Cycles (N): Prior therapy (within 3 mo) Hemoglobin Response*: (initial, final g/dL) Platelet Response*: (initial, final 10(9)/L) Ruxolitinib 1 CI-Spleen 5 D (8.8, 7.6) S (221,212) 2 SD 4 D (10.3,7.9) S (54,46) 3 SD 2 S (8.8,8.9) S (82,101) 4 SD 3 I (8.9,9.8) S (441,458) 5 SD 3 S (9.6, 9.5) I (161, 231) JAK Inhibitor: 6 SD 5 Momelotinib S (9.0, 9.2) S (132,113) 7 SD 1 NS-018 D (8.3, 7.1) D (120,43) 8 SD 3 NS-018 D (10.1,9.0) D (138,111) 9 SD 2 LY2784544 S (8.7,9.1) S (56,21) Other: 10 CI-Spleen 9 Procrit I (10.5,11.9) S (153,198) 11 CI-Spleen 7 None I (8.9,10.2) D (338,133) 12 PD 1 Hydroxyurea S (12.4, 12.2) D (310, 82) 13 SD 1 Procrit D (10.1, 8.6) D (192, 71) 14 SD 1 Hydroxyurea S (9.1,8.9) D (346,119 *S=stable (Hgb +/- 0.5g/dL, Plt +/- 50x109, D=decreasing, I=increasing. Conclusions: Although overall well tolerated, the addition of danazol to ruxolitinib therapy has modest incremental efficacy by IWG-MRT criteria. Clinical improvement was observed in 21.4% of treated patients, however responses were limited to spleen reduction. The degree to which danazol may stabilize expected cytopenias is interesting and may require further investigation. Disclosures Hoffman: Promedior: Research Funding; Geron: Consultancy, Membership on an entity's Board of Directors or advisory committees; All Cells, LLC: Consultancy, Membership on an entity's Board of Directors or advisory committees. Mesa:Gilead: Research Funding; Genentech: Research Funding; Novartis Pharmaceuticals Corporation: Consultancy; CTI Biopharma: Research Funding; Pfizer: Research Funding; Promedior: Research Funding; NS Pharma: Research Funding; Incyte Corporation: Research Funding.

Abstract Abstract 2799 Background: Aurora A kinase (AAK) is important in a diverse set of mitotic processes and is amplified or overexpressed in a number of heme-lymphatic malignancies. MLN8237 is an investigational, orally administered, selective AAK inhibitor in clinical development for the treatment of hematologic and solid tumors. This multicenter study (NCT00697346) is the first phase 1 program to assess safety and pharmacology of MLN8237 in patients with advanced hematologic malignancies. Methods: Eligible patients were aged ≥18 yr, had response-evaluable, relapsed or refractory hematologic malignancies, and had ECOG performance status 0–2; there was no restriction on the number of prior therapies, but prior allogeneic transplant was excluded. Patients received escalating doses of MLN8237 as powder-in-capsule formulation in a 3+3 design. Endpoints included safety, dose-limiting toxicity (DLT), maximum tolerated dose (MTD), pharmacokinetics, and response. Results: Twenty-eight patients were included; median age was 62 yr (range 41–74), 50% were male, 86% were white, and 43% had prior transplant. Diagnoses were non-Hodgkin's lymphoma (68%), including diffuse large B-cell (DLBCL), mantle cell, follicular, and small lymphocytic lymphoma; multiple myeloma (29%); and chronic lymphocytic leukemia (4%). Seventy-nine percent of patients had received ≥3 prior therapies. Patients initially received a 21-day treatment schedule of MLN8237 25 or 35 mg (BID loading dose on Day 1, then QD on Days 2–21) followed by a 7-day rest period (28-day cycles). Based on results with the first two cohorts, subsequent cohorts received a 14-day treatment schedule of MLN8237 35, 45, 65, or 90 mg (BID loading dose on Day 1, then QD on Days 2–14) followed by a 14-day rest period (28-day cycles). Median number of cycles administered was 2 (range 1–14+). After escalation to 90 mg (maximum administered dose), two DLTs per cohort led to de-escalation to 65 mg and then 45 mg, which was the MTD on the 14-day schedule. The most common treatment-related adverse events (AEs) were neutropenia (46%), thrombocytopenia (36%), and asthenic conditions (32%); grade ≥3 treatment-related AEs were reported in 14 (50%) patients, and 13 (46%) had a serious AE. DLTs included grade 3–4 myelosuppression associated with infection or delay in treatment, which were generally manageable by reduction in dose or schedule. AEs were generally reversible and manageable, although 5 (18%) patients discontinued due to AEs. Three patients died, from causes (renal failure; airway obstruction; progressive large cell lymphoma) not considered related to MLN8237. Following multiple doses, an overall median Tmax of 2 hr, a mean t1/2 of 23 hr, and a peak/trough ratio of 5 were observed. The geometric mean of steady-state AUC increased from 19,534 to 30,811 nM*hr when the daily dose was increased from 25 to 65 mg. With the 14-day schedule, antitumor activity was observed in a patient with relapsed DLBCL treated with 65 mg and reduced to 45 mg, who enrolled after disease progression following ifosfamide-carboplatin-etoposide (ICE) salvage therapy. A durable PR coupled with resolution of B symptoms sustained for >1 yr was observed in a patient with post-transplant grade 3B follicular lymphoma treated with 35 mg, escalated per protocol to 45 mg and then 65 mg. Stable disease (SD; 5 months) was observed in a patient with myeloma treated at 90 mg. Conclusions: MLN8237 toxicities were consistent with AAK inhibition in proliferating tissue (chiefly bone marrow), and were generally manageable. The MTD was 45 mg on the 14-day schedule in these patients with advanced hematologic malignancies. Antitumor activity was observed, and repeat cycles were tolerable over 6–12 months in some patients who achieved PR or SD. The results support further investigation of MLN8237 in heme-lymphatic malignancies, and ongoing clinical development includes alternative schedules and formulations. Disclosures: Padmanabhan: Millennium Pharmaceuticals, Inc.: Consultancy, Research Funding. Off Label Use: Investigational agent in clinical development for the treatment of advanced hematologic malignancies. Shea:Millennium Pharmaceuticals, Inc: Consultancy, Research Funding. Vose:Millennium Pharmaceuticals, Inc.: Research Funding. Goy:Millennium Pharmaceuticals, Inc., Celgene, GSK, Genentech: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Zhou:Millennium Pharmaceuticals, Inc.: Employment. Liu:Millennium Pharmaceuticals, Inc.: Employment. Fingert:Millennium Pharmaceuticals, Inc.: Employment, Equity Ownership. Fowler:Millennium Pharmaceuticals, Inc.: Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics: Honoraria, Research Funding; Cephalon: Research Funding; Genentech: Honoraria, Research Funding; Celgene: Honoraria.

Abstract Abstract 3053 Background: Patients with smoldering multiple myeloma (SMM) have a higher chance of progression to active MM than patients with monoclonal gammopathy of undetermined significance (MGUS). Since active MM remains incurable and since patients with SMM can have a long time to requiring treatment, observation remains an option for these patients. Bisphosphonates can prevent the bone complications of myeloma. The immunomodulatory (IMiD) drugs are well-tolerated and have documented anti-tumor activity in active MM. We hypothesized that treatment with the IMiD THAL and a bisphosphonate (ZLD) would prolong the time to progression (TTP) over the control arm of ZLD alone. This is the first report of this phase III trial of THAL/ZLD vs ZLD alone for patients with untreated SMM. Goals: The primary goal of this trial was to compare the TTP between patients treated with THAL/ZLD versus ZLD alone in asymptomatic MM. Secondary goals were progression rate at one year, response rate, duration of response, time to next therapy, and toxicity. Methods: Patients were required to have measurable disease as defined by either a serum monoclonal protein >1.0 g by protein electrophoresis or nephelometry or >200 mg of monoclonal protein in the urine on 24 hour electrophoresis or a measurable soft tissue plasmacytoma; >10% plasma cells as measured on the bone marrow aspirate, bone marrow biopsy, or labeling index; absolute neutrophil count >1500/μL; platelet count >100,000/μL; creatinine <2.0 mg/dL, and a performance status of 0, 1, or 2. Patients could not have symptomatic MM that required chemotherapy. The statistical plan was to accrue 120 eligible patients (60 per arm) over 4 years and after a minimum follow-up of 12 months the study would provide >90% power at a type I error rate of 0.05 to detect an increase in the median TTP from 12 months (ZLD) to 24 months (THAL/ZLD), and >80% power to detect an increase in median TTP from 12 to 21 months). Results: The study was activated in July 2003 and closed March 2009 due to slow accrual. Sixty-eight patients (35 Thal/ZLD; 33 ZLD) with a median age 63 years (range, 47–84) were randomized. The median TTP for Thal/ZLD versus ZLD was 2.4 years versus 1.2 years, respectively, P=0.02 one-sided log-rank. After adjusting for pre-specified stratification factors, the hazard ratio for TTP was 2.2 (one-sided p value = 0.01, univariate stratified Cox PH model) for ZLD compared to Thal/ZLD. 89% of patients on the Thal/ZLD arm were progression-free survival (PFS) at one year compared to 55% on ZLD alone (one-sided p<0.001, chi-square). Similar results were obtained (Table and Figures) when the CRAB (calcium, renal, anemia, bone) criteria were applied. Confirmed response was evaluated using the first 12 months of treatment. In the Thal/ZLD arm the response rate was 31% with a median duration of response of 5.1 years (95% CI: 1.9 - NA). There were no confirmed responses in the ZLD alone arm. The median overall survival has not been reached for either arm. In regards to toxicity, no grade 5 adverse events (AEs) have been reported. Thirty patients have reported grade 3+ AEs (17 Thal/ZLD; 13 ZLD, Fisher's exact p-value 0.47). Eight patients have reported grade 4 adverse events (5 Thal/ZLD; 3 ZLD, Fisher's exact p-value 0.71). Overall, only one grade 4 event was felt to be at least possibly related to study treatment – grade 4 neutropenia in Thal/ZLD. Conclusions: While the trial did not meet its planned accrual goals, there was a significant improvement in improved in outcomes in the Thal/ZLD arm compared to control (ZLD). Thal/ZLD produces anti-tumor responses that are quite durable with the median response duration of over 5 years. ZLD alone did not produce any anti-tumor responses. This study indicates that a non-chemotherapy approach can be effective in SMM and may be a useful strategy to test in future studies. Disclosures: Off Label Use: Thalidomide for smoldering myeloma. Lacy:Celgene: Research Funding. Dispenzieri:Celgene: Honoraria, Research Funding; Binding Site: Honoraria. Kumar:Celgene: Consultancy, Research Funding; Millennium: Research Funding; Merck: Consultancy, Research Funding; Novartis: Research Funding; Genzyme: Consultancy, Research Funding; Cephalon: Research Funding. Gertz:Celgene: Honoraria; Millennium: Honoraria.

Abstract Dexamethasone is a powerful anti-inflammatory, immunosuppressive agent widely used in the treatment of MM with pleiotropic effects on both the tumor, and host immune cells. We report on a completely novel approach to immune modulation using an agent with almost directly opposite effects to glucocorticoids on innate immune cells. LCL161 is an IAP antagonist targeting the cellular inhibitor of apoptosis proteins cIAP1 and -2 (cIAP1/2) that in a phase I study in solid tumors was well tolerated with a cytokine release syndrome as the dose limiting toxicity. We previously reported that loss of cIAP1/2 in MM cells results in the stabilization of NIK and activation of the non-canonical NFkB pathway, a pathway we found frequently activated by a promiscuous array of mutations in multiple myeloma (MM). As expected, we found that LCL161 has no direct anti-tumor activity against MM cells in vitro and ex vivo. However, the non-canonical NFkB pathway is also a key activator of the innate immune response. Remarkably, we found that in vivo LCL161 has dramatic, apoptosis-independent activity associated with marked phagocytosisagainst MM that develops spontaneously in an immunocompetent genetically engineered mouse model of MM (Vk*MYC). Cyclophosphamide (Cy), which has been shown to induce an acute secretory activating phenotype in tumor-associated macrophages, markedly potentiated the anti-tumor effects of LCL161. We show that phagocytes (depleted by liposomal clodronate), but not adaptive immune cells, are required for the anti-tumor effect. Consistently we show that LCL161 activates dendritic cells and macrophages in vitro, and in vivo, and upregulates production of inflammatory cytokines. A phase 2 clinical trial of LCL161 was conducted in 24 patients with relapsed MM previously exposed to both IMiDs and PIs, but less than 5 prior lines of therapy. Patients received LCL161 1200mg po weekly, with Cy 500mg po weekly added for progressive disease or lack of response. Single agent LCL161 was well-tolerated, with grade 3 or 4 non-hematologic toxicity in four patients, and following the addition of cyclophosphamide in 9 patients. No patients responded to single agent LCL161, and the best response was stable disease in 6/24. In 21 patients, Cy was added after a median of 2 cycles, in whom the best response was stable disease or better in 18/21 (p<0.001 compared to LCL161 alone), and a PR or better (including 1 VGPR and 1 CR) in 5/21 (p<0.001 compared to LCL161 alone). Six months following the initiation of Cy, 35% of patients remain event-free. Two patients had stable disease for more than nine months after stopping treatment. One, relapsing after VDT-PACE, HDM200, RVd x 3 years with t(11;14) and del17p, received only three months of LCL161, the last month in combination with Cy. He then achieved a PR, reconstitution of his uninvolved IgG to normal levels for the first time in more than 3 years and still has not progressed one year after stopping therapy. Similar changes in serum and bone marrow inflammatory cytokines and gene expression were observed in patients following treatment with LCL161 to those observed in the mice. We conclude that LCL161 is able to modulate the tumor microenvironment to exert long-term disease control in combination with Cy, and deserves further study in combination with agents that more directly depend on phagocytic cell activity (e.g., monoclonal antibodies, inhibitors of "Don't eat me" signals). Disclosures Bergsagel: Novartis: Research Funding; Constellation Pharmaceuticals: Research Funding; Incyte: Consultancy; Jannsen: Consultancy; Mundipharma: Consultancy. Off Label Use: Use of LCL161 to treat multiple myeloma. Kumar:Celgene: Research Funding; Millenium/Takeda: Research Funding; Onyx: Research Funding; AbbVie: Research Funding; Janssen: Research Funding; Sanofi: Research Funding; Celgene, Millenium, Sanofi, Skyline, BMS, Onyx, Noxxon,: Other: Consultant, no compensation,; Skyline, Noxxon: Honoraria. Stewart:Oncospire Genomics: Research Funding.

Abstract Abstract 3063 Background: The combination of Cyclophosphamide, Bortezomib, and Dexamethasone (CYBOR-D) is proven to be highly active and effective in multiple myeloma. (Reeder, Leukemia 2009) We aim to evaluate the safety and efficacy of this regimen in a separate plasma cell neoplasm, AL Amyloidosis. The primary endpoint of this study is hematologic response. Complete hematologic response is defined as normalization of the free light chain ratio with no evidence of a monoclonal protein by immunofixation. Partial hematologic response is defined as a 50% reduction in M-spike or absolute light chain level (Gertz Am J Heme 2006). Methods: We report a series of patients with symptomatic AL Amyloidosis who received treatment with a combination of Bortezomib (1.3mg/m2 on days 1, 4, 8, and 11 every 28 days or 1.5 mg/m2 weekly), Cyclophosphamide (300 mg/m2 orally weekly) and Dexamethasone (40 mg weekly). We include patients in this study regardless of autologous bone marrow transplant candidacy or previous treatment history. Results: Fifteen patients with AL amyloidosis received two to six cycles of CYBOR-D. The treatment history, bone marrow transplant candidacy prior to treatment, hematological response, and status of transplant after therapy are shown in table 1. Of note, 8 (53%) had symptomatic cardiac involvement all of whom had elevated levels of both cardiac biomarkers (Troponin T and B-natriuretic peptide). Complete hematological response occurred in 11 patients (73.3%) with partial hematological response in 3 patients (20.0%). One patient (6.6%) did not achieve a partial response but did receive autologous bone marrow transplant after treatment with CYBOR-D. Median time to response was 2 months. Six patients (40%) had objective evidence of kidney response to therapy with a greater than 50% decrease in proteinuria. Conclusions: CYBOR-D produces a rapid and complete hematological response in the majority of patients with AL amyloidosis regardless of previous treatment history or bone marrow transplant candidacy. Overall, it is well tolerated with few side effects that included peripheral neuropathy and infectious complications. Two patients originally determined to be not eligible for transplant improved sufficiently on CYBOR-D to become eligible and then went on to receive autologous bone marrow transplant. The retrospective nature and small sample size limit this study, and prospective, randomized studies are needed to further elucidate the role of this regimen in AL amyloidosis. Disclosures: Stewart: Millennium Pharmaceuticals, Inc.: Honoraria, Research Funding; Celgene: Honoraria. Fonseca:Amgen: Consultancy; Bristol-Myers Squibb: Consultancy; Celgene: Consultancy, Research Funding; Genzyme: Consultancy; Onyx: Research Funding; Otsuka: Consultancy; Medtronic: Consultancy.

Abstract Abstract 4527 Introduction: The prognosis for pts with intermediate or high risk AML remains dismal, with relapse rates typically in the 60–80% range after treatment with chemotherapy alone. While allo-SCT can decrease the risk of relapse to 10–20%, widespread use of this modality is limited by relatively high rates of non-relapse mortality (NRM), often due to severe acute and/or chronic GVHD. Attenuation of severe GVHD, without a concomitant increase in relapse or NRM, should improve outcomes and result in cure of a larger fraction of AML pts. We therefore investigated the use of in-vivo T-cell depletion with r-ATG in pts with intermediate- or high-risk AML but without active leukemia at the time of allo-SCT. Patients and Methods: Pts (n = 43) were included in this retrospective analysis if they were between 18 and 65 years of age and had no evidence of active AML at the time of allo-SCT (see Table). All pts had 1 or more high-risk features: 1) adverse or intermediate risk cytogenetics (without NPM1 mutation if cytogenetically normal); 2) therapy-related or secondary AML; 3) high WBC count at diagnosis; 4) failure to achieve CR after 1 cycle of induction; or 5) not in CR1 at allo-SCT. Among the 43 pts, 10 received grafts from related donors, 14 from 10/10 matched unrelated donors (URDs), and 19 from mismatched URDs (9/10, n = 11; 8/10, n = 8). All pts received r-ATG according to institutional standard operating policy, with doses ranging from 2.5 – 10 mg/kg depending on donor type and degree of mismatch. All transplants were performed using PBSC. Additional GVHD prophylaxis included tacrolimus plus either methotrexate or mycophenolate mofetil. Results: The median age was 47 (range 20 – 65), and median follow-up for surviving pts is 12 (range 1 – 66) months. As of 8/5/11, 39 pts were alive, and 4 had died from multiorgan failure (n = 1), relapse (n = 1), GVHD (n = 1), and veno-occlusive disease (n = 1). The 2-year estimate of PFS is 84.7% (Fig. 1). The 2-year cumulative incidence of relapse is 6.8% (2 pts, days 97 and 147), and of non-relapse mortality 9.4%. Three pts developed severe (grades III-IV) acute GVHD by day 100 (cumulative incidence 4.6% at day 100) with no additional cases of severe acute GVHD beyond day 100. To date, 4 pts have developed moderate/severe chronic GVHD (cumulative incidence 16.8% at 2 yrs), with one death at day 344 related to complications of acute and chronic GVHD. CMV reactivation occurred in 29 pts (56%), with no deaths related to CMV. Three pts have reactivated EBV, with one case of PTLD (all treated with Rituximab). Conclusions: In this retrospective analysis of single center data, the inclusion of r-ATG in the GVHD prophylactic strategy appeared to significantly attenuate the incidence and severity of both acute and chronic GVHD. Although follow-up is relatively early, the incidence of relapse and NRM does not appear to be increased compared to contemporaneous pts treated without ATG. Given that almost half of the pts received grafts from mismatched URDs, this abrogation in risk of GVHD is significant and clinically relevant. While randomized studies are needed, these data suggest that in-vivo T-cell depletion with r-ATG ameliorates severe GVHD, without increasing relapse or non-relapse mortality, in AML pts without overt leukemia at the time of allo-SCT. Using this strategy, cure rates of 70 – 80% may be realistic and attainable for younger (</= age 65) AML patients who achieve a leukemia-free state and who have a reasonably matched related or unrelated donor. Disclosures: Reeder: Celgene: Research Funding; Millennium Pharmaceuticals Inc.: Research Funding; Novartis: Research Funding.

Abstract Multiple myeloma tumors universally target one of the three human cyclin D genes (CCND1, CCND2 or CCND3) for dysregulation (Bergsagel et al., 2005, Blood, 106:296). Using a lentivirus expressing CCND2 RNAi we first tested the effects of selective cyclin D2 knock down on My5 and H929 myeloma cell lines and found G0/G1 phase arrest, increased apoptosis and significant selective disadvantage in transfected cells. By comparison, knockout mouse models indicate that most somatic tissues can develop in the total absence of cyclin D1, D2 and D3 (Kozar et al., 2004, Cell,118:477). Targeted inhibition of specific cyclin D expression is therefore a rational therapeutic strategy in myeloma. To identify novel pharmaceutical inhibitors of CCND2 transactivation we developed an assay employing NIH 3T3 cells stably co-expressing the CCND2 transactivator c-Maf and the cyclin D2 promoter driving firefly luciferase (luc) and screened the Lopac (n=1280), Prestwick (n=1120) and Spectrum (n=2000) libraries of drugs and natural compounds. In a parallel MTS assay, the effect of each compound on 3T3 viability was determined, allowing exclusion of compounds that caused secondary suppression of CCND2 due to non-specific cytotoxicity. From the screen we identified 10 c-Maf independent putative CCND2 inhibitors. These included monensin, patulin, β-lapachone, camptothecin, dihydrogambogic acid, gentian violet, thapsigargin, brefeldin A, pristimerin and kinetin riboside. Three of the 10 compounds (gentian violet, thapsigargin and patulin) were not studied further due to toxicity cited in the literature. Subsequent validation studies using selected compounds in human myeloma cell lines (HMCL) confirmed successful suppression of both cyclin D2 and D1 proteins. Each of these compounds was then shown to be cytotoxic to a genetically diverse and standardized panel of 14 HMCL in MTT assays: monensin (10–760 nM), camptothecin (5–700nM), dihydrogambogic acid (250–800 nM), pristimerin (150–500 nM) and kinetin riboside (2.5–20μM). Cell cycle analysis confirmed induction of G0/G1 phase arrest for most compounds, consistent with cyclin D inhibition. However, camptothecin and b-lapachone induced S-phase arrest, suggesting secondary suppression of cyclin D by virtue of S-phase activity. Unsorted myeloma patient bone marrow samples demonstrated selective activity for pristimerin, dihydrogambogic acid and kinetin riboside against CD138+ myeloma cells compared with non malignant hematopoietic cells; by contrast monensin showed almost equal toxicity for normal cells. The triterpenoid, pristimerin, showed potent anti-myeloma activity and was examined in greater detail. Studies confirm that pristimerin rapidly inhibits cyclin D1, D2 and D3 expression (<6 hours) at nanomolar concentrations and induces apoptosis of primary myeloma cells characterized by caspase 9 cleavage and Annexin V binding. While pristimerin is cytotoxic to HMCL and patient myeloma cells at 0.1–0.15 mg/L, toxicity studies in vivo indicate that the drug is tolerated in mice at 2.5 mg/kg i.p. daily. In vivo activity against a xenograft model is currently being determined. Overall this targeted chemical biology screen has identified several compounds, including the triterpenoid, pristimerin, that are being further characterized for promising preclinical anti-myeloma activity.

Abstract Abstract 2699 Poster Board II-675 Introduction: High-dose chemotherapy with autologous stem cell transplant (SCT) is a standard treatment option for younger patients with aggressive non-Hodgkin's lymphomas (a-NHL) who fail to respond, or relapse after initial therapy. For patients who relapse after SCT there are few effective treatment options and prognosis remains poor (Vose et al Blood. 80(8):2142–8, 1992). A second SCT was shown to achieve only marginal responses and at an increased risk of toxic death (Lenain et al Hematol J. 5(5):403–9, 2004). Therefore, new approaches are needed for treatment of patients in this poor prognostic group. Lenalidomide (Revlimid®) is an immunomodulatory agent that has shown clinical activity in treatment of several B-cell malignancies. Two phase 2 studies of lenalidomide monotherapy in patients with relapsed or refractory (R/R) a-NHL were conducted in the US (NHL-002; Wiernik et al JCO 26:4952–7, 2008) and internationally (CC-5013 NHL-003). In an extended follow-up of the NHL-002 study, the overall response rate (ORR) was 35%, which included 12% of patients with a complete response (CR), and a median duration of response (DR) lasting 10.4 months (Wiernik et al 2008 EHA. Abst: 764). Comparable efficacy was observed in the larger confirmatory, phase 2, NHL-003 study of lenalidomide in a similar patient population. The goal of this analysis was to learn the ORR and DR to lenalidomide in patients with a prior SCT. Methods: Patient data from both phase II studies were pooled for this report. Eligibility for both studies was similar – patients with R/R a-NHL, which included diffuse large B-cell lymphoma (DLBCL), mantle cell lymphoma (MCL), transformed lymphoma (TL), and follicular lymphoma grade III (FL-III), with measurable disease (≥ 2 cm), and ≥ 1 prior treatment regimen. Patients received oral lenalidomide 25 mg once daily on days 1–21 of a 28-day cycle. Protocol defined treatment continued for up to 52 wks in NHL-002, or until disease progression in NHL-003. Primary endpoint was ORR; secondary endpoints included DR, progression-free survival (PFS), and safety. Results: 87 patients with a prior SCT (14 patients from NHL-002; 73 patients from NHL-003) were included in this analysis. Median age of patients was 61 yrs (range, 23–76), with a median of 4 prior therapies (range, 2–12). The ORR to lenalidomide was 39% (34/87), with 13% (11/87) CR/CRu and 26% (23/87) partial response (PR). Median PFS for all 87 patients was 3.8 months (95% CI, 2.6, 5.6) and the DR for 34 responders was 9.7 months (95% CI, 4.2, 16.3). Responses occurred in 15 of 52 patients (29% ORR; 10% CR/CRu) with DLBCL, 12 of 19 patients with MCL (63% ORR; 26% CR/CRu), and in 6 of 10 patients with TL (60% ORR; 10% CR/CRu). The table summarizes responses for patients who did not have a transplant, for those who had a SCT anytime prior to lenalidomide; as the last therapy prior to lenalidomide; and not as last therapy prior to lenalidomide. Most common grade 3 or 4 adverse events were neutropenia (44%), thrombocytopenia (33%), and anemia (9%). Eighteen (20.6%) patients discontinued treatment due to adverse events. Patients with a prior history of SCT appeared to have a significantly higher rate of thrombocytopenia, all grades (51% v 30%; P = 0.001), and grades 3 or 4 (33% v 16%; P = 0.002). Patients with a prior SCT were also more likely to experience a dose reduction/interruption due to thrombocytopenia compared with those without a prior SCT (25% v 14%; P = 0.027). Conclusions: Based on a pooled dataset from two phase II studies, oral lenalidomide monotherapy appears to be a well tolerated and active therapy resulting in durable responses in patients with R/R a-NHL who had a prior SCT. Furthermore, the potential of achieving a response to lenalidomide appears to be independent of prior history of SCT. Disclosures: Vose: Celgene: Research Funding. Off Label Use: Lenalidomide for the treatment of relapsed/refractory aggressive non-Hodgkin's lymphoma. . Czuczman:Celgene: Research Funding. Zinzani:Celgene: Research Funding. Tuscano:Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees. Pietronigro:Celgene: Employment, Equity Ownership. Ervin-Haynes:Celgene: Employment. Witzig:Celgene: Research Funding.