Buadi, Francis K.

Background: Autologous stem cell transplantation is an effective treatment modality for patients with multiple myeloma. While most of the patients relapse after ASCT with a median time to progression of 2 years, there is a significant heterogeneity in the duration of response. It has been hypothesized that the effect of high dose alkylator therapy used for conditioning may have a dual effect on the myeloma cells as well as marrow microenvironment. It is also known that hematopoiesis, especially thrombopoiesis, depends to some extent on signals form the marrow microenvironment. We examined if there was any relationship between delayed platelet engraftment and outcome after ASCT. Methods: We examined the outcomes in a group of patients undergoing ASCT for myeloma at our institution to compare the response duration to platelet engraftment kinetics. We studied 687 patients undergoing ASCT with melphalan conditioning followed by peripheral blood stem cell transplant. Results: Among the 687 patients undergoing ASCT, 200 pts (29%) achieved a platelet count of 50,000 by day 21 (early group) and the rest achieved this level after 21 days or never engrafted (late group). The median time to progression (TTP) among the late group was 24.8 months (95% CI; 19.6, 30 months) vs. 16.8 months (95% CI; 15.1, 18.6 months) for the late group (p < 0.001) (Figure). Patients in the late engraftment group were more likely to achieve a complete response compared to the early group; 39% vs. 30%, p = 0.02. In a multivariate analysis examining factors predicting for longer time to progression after ASCT, delayed platelet engraftment was independent of transplant within 12 months of diagnosis, CR with ASCT, absence of cytogenetic abnormalities, B2M < 3.5 mg/L and a plasma cell labeling index < 1% at the time of ASCT (Table). Conclusions: In this study, we have demonstrated for the first time a relationship between delayed platelet engraftment after ASCT and the duration of response following ASCT. This intriguing finding raises several hypotheses. It is possible that the delayed platelet engraftment is a marker of marrow microenvironment dysfunction secondary to high dose therapy, given the role of marrow microenvironment on thrombopoiesis. It is possible that this is a surrogate marker for the biological effectiveness of the melphalan dose, which can affect the other cells in the marrow microenvironment as well. It is likely a reflection of the marrow microenvironment dependence on the myeloma cells for its survival. These findings should be confirmed in other larger patient groups. Predictors of progression Variable Hazard Ratio P Platelet Engraftment > 21 days 0.80 (0.60, 0.96) 0.02 Late transplant (>12 months from diagnosis) 1.6 (1.3, 2.0) <0.01 Plasma cell labeling index > 1% 1.9 (1.5, 2.4) <0.01 Complete response 0.41 (0.33, 0.51) <0.01 Abnormal Cytogenetics 1.8 (1.4, 2.3) <0.01 B2M > 3.5 1.2 (0.96, 1.5) 0.12 Figure Figure

Abstract Background: Pomalidomide is an immunomodulatory agent (IMiD®) that has been approved for treatment of relapsed and refractory multiple myeloma (MM). Combinations of IMiDs and proteasome inhibitors offer the potential for deeper and more durable responses due to enhanced efficacy. Preliminary results of a phase 1 study of twice weekly bortezomib with pomalidomide have been reported with promising results (Richardson, ASH 2012). This phase I/II trial was designed to evaluate the maximum tolerated doses (MTD) as well as safety and efficacy of the combination of pomalidomide, once weekly bortezomib and dexamethasone (PVD) in patients with relapsed, lenalidomide refractory, MM. Patients and methods: We included patients with relapsed MM who had 1-4 prior lines of therapy and were resistant or refractory to lenalidomide. In the phase I portion of the trial, dose level 1 consisted of pomalidomide 4 mg days 1-21 PO, bortezomib 1.0mg/m2 days 1,8,15, and 22 IV or SQ and dexamethasone 40 mg days 1,8,15, and 22 PO, given every 28 days. Bortezomib was increased to 1.3mg/m2 for dose level 2 and and was adopted for the phase 2 portion. The primary aim of the phase I cohort was to determine the MTD of the combination, and for the phase II cohort was to evaluate the confirmed response rate (PR, VGPR, or CR) in relapsed refractory MM. Response was assessed by the IMWG criteria and toxicity was graded using the CTCAE v4.0. Results: 50 patients were accrued between March 2012 and July 2014 (dose level (DL)1: 3, DL 2: 6, Phase II: 41). We describe results in 47 patients treated at MTD and phase II. Median age was 66, 51% were female and median time from diagnosis to study was 46 months (15-142). Twenty five percent had mSMART defined high-risk status. Median number of prior regimens was 3. All patients had prior lenalidomide, 68% had stem cell transplant, 17% received thalidomide, 56% had alkylators and 57% had bortezomib. With median follow up of 9 months, 72% remain progression free, 96% are alive and 66% remain on treatment. The most common AEs at least possibly attributable to the combination were anemia, fatigue, leukopenia and thrombocytopenia; however, the majority of these were grade 1-2. Grade ≥3 AEs (regardless of attribution) that occurred in at least 3 patients included neutropenia (29), leukopenia (15), lung infection (6), lymphopenia (8) dyspnea (3) and syncope (3). DVT/PE occurred in one patient. Among the 42 patients who were evaluable, confirmed responses (PR, VGPR, or CR) were seen in 34 (81%) including sCR (3), CR (5), VGPR (8), PR (18). Confirmed responses were seen in 9 of 11( 82%) high risk patients. Median progression free survival was 17.7 months (95%CI: 9.5-NA). Conclusions: PVD is a highly effective combination in patients refractory to lenalidomide with confirmed responses in over 80%. Weekly administration of bortezomib enhanced the tolerability and convenience of this regimen. Toxicities are manageable, mostly consisting of mild cytopenias with no significant neuropathy or DVT. PVD is a highly attractive option in patients with relapsed and refractory MM. Disclosures Lacy: Celgene: Research Funding. Lust:Senesco: PI Other. Fonseca:Medtronic, Otsuka, Celgene, Genzyme, BMS, Lilly, Onyx, Binding Site, Millennium, AMGEN: Consultancy, patent for the prognostication of MM based on genetic categorization of the disease. He also has sponsored research from Cylene and Onyx Other, Research Funding. Stewart:Celgene: Consultancy; Novartis: Consultancy; Array BioPharma: Consultancy; BMS: Consultancy; Millenium: Research Funding. Reeder:Millennium, Celgene, Novartis: Research Funding. Mikhael:Onyx: Research Funding; Celgene: Research Funding; Sanofi: Research Funding; Novartis: Research Funding.

Abstract Background Conflicting results have emerged, especially with respect to the impact on overall survival (OS), from trials evaluating lenalidomide maintenance (LM) therapy after induction therapy alone or post-autologous stem cell transplant (ASCT) in multiple myeloma (MM). We performed a systematic review and meta-analysis of existing outcome data from LM trials to evaluate role of lenalidomide as maintenance strategy in MM. Patients and methods A comprehensive search of electronic databases and abstracts through June 2013 was performed to identify randomized controlled trials (RCTs) that compared LM vs. placebo/no maintenance. Single arm studies were excluded. Pooled hazard ratio (HR) or odds ratio (OR) estimates with 95% confidence intervals (CIs) were calculated using the random-effects model for clinical endpoints of progression free survival (PFS), OS, response rate (RR) and adverse events (AEs), including second primary malignancies (SPMs). Analyses were performed using Comprehensive Meta-Analysis Software Version 2. We assessed between-study heterogeneity with the Cochran Q test and quantified its extent with the I2 statistic. Results Overall, five RCTs, with data extractable from four phase III trials (3 publications and 1 abstract) were identified (n= 1935). All studies were RCTs with an adequate randomization. MRC MM XI study was excluded from analyses as survival data are not available. Two placebo controlled trials (IFM 05-02, CALGB 100104) addressed the role of LM post-ASCT, one placebo-controlled trial (MM-015) studied LM therapy in the non-transplant setting and the remaining trial (RV-MM-PI209) had a 2 X 2 design comprising of both ASCT and non-transplant randomized arms followed by a second randomization of LM versus no maintenance. There was no heterogeneity for estimate of PFS results (Cochran Q, p=0.68; I2=0%), but considerable heterogeneity for estimate of OS (Cochran Q, p=0.09; I2= 55%), among the studies. There was significant prolongation of both PFS (HR 0.49, 95% CI, 0.41–0.58, p<0.001) and OS (HR 0.77, 95% CI, 0.62–0.95, p=0.013) with LM vs. placebo/no maintenance (Figure 1). Best response during maintenance was reported only in 2 studies and odds of responding (very good partial response or better) were not significantly different with LM (OR 1.28, p=0.3). Grade 3-4 AEs data were available from 3 trials for calculation of pooled OR with LM compared with placebo. We observed a nearly two-fold increase in the risk of SPMs with LM (OR 1.99; 95% CI, 1.31–3.04; p=0.001). Patients on LM were more likely to have grade 3-4 AEs than placebo: neutropenia (OR 4.9, p<0.001), thrombocytopenia (OR 2.7, p<0.001), fatigue (OR 2.3, p=0.01) and venous thromboembolism (OR 3.2, p=0.02). Odds of discontinuing treatment were also significantly higher in patients on lenalidomide (OR 2.9, p<0.001). Conclusions Meta-analysis of RCTs demonstrates significant improvement in PFS and modest improvement in OS with LM. There is an increased risk of grade 3-4 adverse effects, including SPMs with LM. Substantial heterogeneity for estimate of OS among protocols is a limitation of this analysis. Lack of uniform access to lenalidomide upon disease progression in the placebo/no maintenance arms of the constituent studies should be taken into account while interpreting aggregate effect estimates for OS in this meta-analysis. OS: Cochran Q p=0.09, I2=55%, substantial heterogeneity PFS: Cochran Q p=0.68, I2=0%, minimal heterogeneity Disclosures: Off Label Use: Lenalidomide for maintenance therapy in multiple myeloma. Kumar:Merck: Consultancy, Honoraria; Celgene: Consultancy, Research Funding; Millennium: The Takeda Oncology Company: Research Funding; Novartis: Research Funding; Genzyme: Research Funding. Dispenzieri:Celgene, Millenium, Jansenn, Pfizer: Research Funding. Bergsagel:Onyx: Consultancy. Lacy:Celgene Corporation: Research Funding.

Abstract There are a number of rare monoclonal gammopathies that do not have a characteristic laboratory, imaging, or pathologic study. Recognition requires keeping the specific syndrome in mind. This article reviews 6 rare syndromes associated with monoclonal proteins and gives specific “pearls” so a clinician can be certain not to overlook these important disorders that easily can be misdiagnosed as MGUS, Waldenstrom, and multiple myeloma.

Abstract Background: Previous studies have demonstrated inferior overall survival (OS) among patients with AL amyloidosis who have bone marrow plasmacytosis (BMPC) >10%. It is well recognized that AL patients who achieve the deepest hematologic responses have superior organ response and OS rate. Methods: We designed a study to determine if BMPC% affects CR rate post ASCT and whether pre-transplant induction therapy improves response rate and OS among patients with a higher baseline BMPC burden. Results: Among 415 AL patients who underwent ASCT at Mayo Clinic, Rochester within 12 months of diagnosis, 116 (28%) had BMPC>10% at diagnosis. The median age was 57.2 years. The median follow up for surviving patients was 67.3 months. There was no statistically significant difference in age, gender, time from diagnosis to transplant, or use of attenuated conditioning regimen between groups with high (>10%) and low (≤ 10%) bone marrow involvement. The high BMPC group tended to receive more induction chemotherapy before ASCT, and presented with greater value of albumin, beta-2 microglobulin and difference in serum free light chain (dFLC). A higher CR rate was observed in low BMPC group (44.6% versus 26.7%, p=0.0013). In patients with high BMPC, a higher CR rate (33.9% versus 17.7%, p<0.05) was seen in those who received pre-ASCT induction therapy compared with no induction therapy. Among 3 groups of patients who had: no pre-ASCT therapy; steroid only as induction; and induction chemotherapy, the 5-year OS rates were 50.5%, 40% & 67.5%, respectively, p<0.03. Conclusions: Lower bone marrow burden at diagnosis yielded a deeper response following ASCT. Compared to no therapy, patients who were treated with steroid only pre-ASCT had an inferior OS, but other induction regimens appeared to improve survival. These data would support the concept that using induction therapy prior to ASCT conditioning among patients with higher tumor burden may be of value. Figure 1. In BMPC > 10% at diagnosis, OS comparison between induction therapies pre-ASCT Figure 1. In BMPC > 10% at diagnosis, OS comparison between induction therapies pre-ASCT Figure 2. Figure 2. Figure 3. Figure 3. Disclosures Kumar: Celgene: Research Funding; Celgene, Millenium, Sanofi, Skyline, BMS, Onyx, Noxxon,: Other: Consultant, no compensation,; Sanofi: Research Funding; AbbVie: Research Funding; Millenium/Takeda: Research Funding; Onyx: Research Funding; Skyline, Noxxon: Honoraria; Janssen: Research Funding. Gertz:Celgene: Honoraria; millenium: Consultancy, Honoraria; Onyx: Honoraria; Novartis: Honoraria; Smith Kline: Honoraria.

Abstract Background: Patients with light chain amyloidosis (AL) often have delayed diagnosis and present with significant symptomatology; this may result in decreased quality of life (QOL). With improving treatment options providing longer survival, it is increasingly important to assess QOL. However there is paucity of data in the literature addressing QOL in AL patients. We prospectively employ a "Hematology Patient Reported Symptom Screen" (HPRSS) which consists of three questions about fatigue, pain and overall QOL. The aim of this study is to understand if HPRSS parameters predict various clinical outcomes. Methods: Eligibility for this retrospective study was as follows: 1) New diagnosis of AL between 2009-2014; 2) baseline HPRSS documented in the medical record; and 3) at least a year of follow-up, which included either death within or follow-up through 12 months after diagnosis. The HPRSS questions were rated on a 1-10 scale, with 10 being the worst for fatigue and pain, and 10 being the best for overall QOL. Scores were abstracted from visits at time of diagnosis, and at 12 months +/- 1 month post-diagnosis. We considered a 2-point difference in serial scores a "change" over time. Results: For the 302 patients in this study, the baseline median scores [interquartile range] for fatigue, pain, and QOL were 6 [3,7], 2 [0,5] and 5 [3,8], respectively. Median overall survival (OS) was 39.1 months, with 102 deaths in the first year. There were significant differences in baseline HPRSS between those who lived longer than one year and the early death patients in the domains of fatigue (5 [IQR 3, 7] vs. 7 [IQR 5, 8], p<0.0001) and QOL (6 [IQR 4, 8] vs. 5 [IQR 3, 7], p=0.006), but not in pain (2 [IQR 0, 5] vs. 2 [IQR 0, 5]). There were significant baseline differences in the early death group for alkaline phosphatase, bilirubin, creatinine, and Mayo stage. Patients who received ASCT had the best baseline fatigue 4 [2.5,6] and QOL 7 [5,8] scores and were significantly different from those who did not receive ASCT [fatigue p<0.0001) and QOL (p<0.0001)] On univariate analysis fatigue and QOL were prognostic for OS. On multivariate analysis Mayo 2012 staging, autologous stem cell transplant and baseline fatigue remained independently prognostic. When analyses were restricted to the 125 patients with HPRSS measurements at 12 months, we found that over time QOL scores improved significantly 6 [IQR 3.5, 8] to 7 [IQR 5, 8] (two sided Wilcoxon signed rank p=0.01), but fatigue (5 [IQR 2, 5] to 4.5 [IQR 3, 6]) and pain scores (2 [IQR 0 ,4] to 1.5 [IQR 0, 4]) did not. Patients with worse baseline parameters tended to have improvement in QOL by 12 months while those with the best baseline parameters tended to decline in QOL although not statistically significant. When we included the 102 patients who died within 12 months to the comparison, the early death patients had the worst baseline parameters and there were significant differences across all 4 groups for most characteristics (Table 1). There was no association between achieving hematologic or organ response with change in QOL. Conclusion: Asking patients with AL to rate their fatigue and QOL using a 10-point scale has predictive value. Patient reported fatigue at diagnosis is an independent prognostic factor for survival. Survival at one year was associated with significant improvement in QOL. Table 1. Baseline parameters between patients with early death and/or survive 12 months. Grouped by Patient Reported QOL at 12 months Relative to Baseline Dead by 12 months, n=102 Improved, n=44 Stable, n=55 Worsened, n=26 pa HPRSS scores [IQR] Baseline QOL Baseline fatigue Baseline pain 12 month QOL 12 month fatigue 12 month pain 5 [3,7] 7 [5,8] 2 [0,5] NA NA NA 4 [3-5] b,c,d6 [4-8] b,c2 [0-4] 7 [6-9] b,d4 [1.25-6] 1 [0-3] 7 [4-8] 4 [2-7] 2 [1-5] 7 [4-8] 5 [3-6] 2 [0-4] 8 [7-10] 2.5 [0-5.25] 2 [0-6.25] 5 [3-7] 5 [3-6] 2.5 [1-4] <0.0001 <0.0001 NS NS 0.001 NS dFLC, mg/dL 48 (2.89-726) 30 (1.1-494) 19 (36-455) 22 (0.2-2097) 0.008 Troponin, ng/mL 0.065 (<0.01-0.84) 0.02 (<0.01-1.6) 0.01 (<0.01-0.19) 0.01 (<0.01-0.14) <0.0001 NT-proBNP pg/mL 5222 (159-70,000) 1766 (26-16868) 1381 (24-19180) 496 (56-2973) <0.0001 Received Transplant (%) 4 (4) 13 (33) 36 (50) 13 (50) 0.0002 a Significant by Wilcoxon across all 4 categories; b Significant difference between Improved and Worsened; c Significant difference between Improved and Stable; d Significant difference between Worsened and Stable Disclosures Kumar: Millenium: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Abbvie: Research Funding; Janssen: Consultancy, Research Funding; BMS: Consultancy, Research Funding; Novartis: Research Funding; Onyx: Consultancy, Research Funding. Thompson:Kite Pharma: Research Funding.

Abstract Background: Outcome studies for the unique cohort of young patients with multiple myeloma (MM) are sparse. In general, MM is a heterogenous disease with the genetic signature being one of the major determinants of prognosis. We have recently reported on improvement in overall survival (OS) of young patients with the use of novel agents, but the maximal survival gain has been achieved by integrating autologous stem cell transplant (SCT) to our current approach. Herein, we report on outcomes of patients with MM who were 50 years or younger at diagnosis and stratified by fluorescence in situ hybridization (FISH) results. Our study focuses on t(11;14) myeloma as its prognostic impact remains unclear with the use of novel agents upfront. Methods: Out of 1384 patients with MM, evaluated consecutively at Mayo Clinic, Rochester, MN between 1/1/2000 and 12/31/2011, 290 (21%) were 50 years or younger at diagnosis. Interphase FISH, performed within 100 days of diagnosis of MM, was utilized to stratify patients as high-risk [deletion 17p, t(14;16), t(14;20) or t(4;14)] or standard-risk [normal FISH, trisomies, t(11;14), t(6;14) or monosomy13/deletion 13q]. FISH results were available in 125 young patients that comprise the cohort of interest in the current study. OS from diagnosis was estimated by the Kaplan-Meier method. Results: Median age at diagnosis of MM was 47 years (range: 22 to 50 years) and 58% of the patients were male. At the time of data cut-off (7/31/2014), 45 (36%) patients had died with 90% of all known causes of deaths (n=39) being MM related. FISH abnormalities were noted in 114 (91%) patients. At diagnosis, 46%, 30% and 24% patients were categorized as International Staging System (ISS) stage I, II and III, respectively. The estimated median follow up was 60 months (95% CI: 54-67) and the 5-year OS rate was 69% [median 86 months (95% CI: 76-108)]. Standard (n=100; 80%) and high (n=25; 20%) risk patients had a median OS of 89 months (95% CI: 76-108) and 77.6 months (95% CI: 42-130), respectively (p=0.87). In order to further investigate the similar outcomes between these broad risk-groups with typically diverse disease course, we assessed the outcomes based on the common genetic abnormalities (Table 1) within each of the 2 categories. Presence of t(11;14) (n=37; 29%) was associated with a significantly shorter median OS (76 months) compared to patients with trisomic and normal FISH profile (n=46) (91 months, p=0.01; Figure 1). Patients with t(11;14) also had a significantly shorter median OS compared to those with other standard-risk FISH abnormalities (median OS 96 months, p=0.02). Presence of t(11;14) was not associated with higher plasma cell labeling index (PCLI, p=0.29) or worse ISS stage (p=0.99) compared to patients without t(11;14). OS survival of patients with t(11;14) was similar to those with high risk features (median 76.2 vs. 77.6 months, p=0.32). Of 24 (65%) patients with t(11;14) who underwent SCT, 79% had early SCT (within 12 months from diagnosis). Median OS was 79.4 months (95% CI: 36-108) vs. not reached (NR) (95% CI: 27-NR), respectively (p=0.79) in early versus late SCT. Twenty-one (57%) and 13 (35%) patients with t(11;14) received initial immunomodulatory drugs or bortezomib-based therapies, respectively. Those receiving frontline bortezomib had a higher median OS (76.2 months, 95% CI 76-79) compared to 64.8 months (95% CI 32-108) with other initial agents although it did not reach statistical significance (p=0.78). Conclusion: Presence of t(11;14) is associated with an inferior OS compared to patients with normal FISH, trisomies, or other standard risk abnormalities in young patients with MM. Given, the inherent biases associated with a retrospective study from a referral institution, our findings require external validation. However, our data suggest that our current therapeutic approaches in managing young patients with this unique genetic signature are inadequate. Table 1FISHn(%)Median OS in months (95% CI)t(11;14)37(29)76.2 (53.5-107.7)Trisomies35(28)91.3 (76.4-NR)13/del(13q)11(9)NR (32-NR)Normal11(9)95.5 (45.4-95.6)t(4;14)11(9)NR (40.1-NR)del(17p)/-1710(8)42 (19.2-129.6)t(14;16)4(3)77.6 (42.4-NR)Others6(5)NR (11.5-NR) Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

Abstract Abstract 201 Background: Pomalidomide at doses of 2 or 4 mg/d has demonstrated excellent activity in patients with relapsed multiple myeloma (MM). Between November 2007 and March 2012, we opened 6 sequential phase 2 trials and treated 345 patients with relapsed MM with pomalidomide at differing doses with weekly dexamethasone (Pom/dex). Results of 164 of these patients have been previously published. Here we describe long term follow up of these patients as well as results of an additional 181 patients with relapsed MM treated with the Pom/dex regimen. Methods: The six cohorts consisted of: Cohort 1 (N=60): relapsed MM with 1–3 prior regimens, 2 mg dose; Cohort 2 (N=34): lenalidomide (LEN) refractory, 2 mg dose; Cohort 3 (N=35): BZ)/LEN refractory, 2 mg dose; Cohort 4 (N=35): BZ/LEN refractory, 4 mg dose; Cohort 5 (N=60) LEN refractory, 1–3 prior regimens, 4 mg dose; and Cohort 6 (N=120) LEN refractory, 4 mg dose. Pomalidomide was given orally 2 mg daily or 4mg daily on days 1–28(cohorts 1–5) or 1–21 (cohort 6) of a 28-day cycle with oral dexamethasone given 40 mg daily on days 1, 8, 15 and 22. Response was assessed by the International Myeloma Working Group Uniform Response criteria. All patients received aspirin 325 mg daily for deep venous thrombosis (VTE) prophylaxis or full dose anticoagulation. Results: A total of 345 patients were enrolled across all 6 cohorts. One patient was ineligible and excluded from analysis. The median age was 64 years (32–88). The median time since diagnosis was 53 months. The median number of prior therapies was 3 (1–14). 147 (44%) had high-risk molecular markers by mSMART criteria. Prior therapies consisted of thalidomide 52%, lenalidomide 87%, bortezomib 75%, autologous stem cell transplant 70% and allogeneic transplant 3%. The median follow-up is 10.4 months (5.4–34 months). Sixty-seven percent are alive and 32% remain progression free. 46 patients are continuing to receive treatment. The most common toxicities (grade 3 or higher) were neutropenia (31%), anemia (16%), thrombocytopenia (12%), pneumonia (8%) and fatigue (8%). VTE was seen in 10 patients (3%). Outcomes are shown in Table 1. Across all 6 cohorts confirmed responses of partial response (PR) or better were seen in 34%. The response rate in all patients with mSMART high risk status was 30.6%. Responses and duration of response (DOR) in those with high risk molecular markers include: 17p– 19 of 56 (34%) DOR 8.2 months; t(4;14) 6 of 24 (25%) and DOR 4.8 months; t(14;16) 7 of 11(64%) and DOR 9.5 months; deletion 13 by cytogenetics 13 of 37 (35%) with DOR 8.2 months. In a multivariate analysis, only LDH > ULN, number of prior regimens, and prior BZ therapy were predictive of a shorter TTP and factors associated with a poor OS following initiation of pomalidomide therapy included B2M > 5.5, LDH > ULN,number of prior regimens, and prior BZ therapy. Conclusions: Pom/dex is active and well tolerated even in heavily pretreated patients and those with high risk molecular markers. Remissions are durable. Response rates and toxicity are similar between the 2 mg and 4 mg doses. Disclosures: Lacy: Celgene: Research Funding. Stewart:Celgene: Consultancy, Honoraria. Reeder:Celgene: Mayo Clinic receives funding from Celgene to support clinical trials Other, Research Funding.

Abstract Abstract 1845 Poster Board I-871 Background: Proteasome inhibition is an effective strategy for the treatment of multiple myeloma. In patients, proteasome inhibition has primarily been measured in peripheral blood samples (whole blood or mononuclear cells). However, it is unknown whether myeloma cells in the bone marrow (BM) are equally sensitive to proteasome inhibitors such as bortezomib (BTZ) and carfilzomib (CFZ). Aim: To measure proteasome inhibition in purified tumor cells from BM samples taken from patients enrolled in two ongoing Phase 2 trials of single agent CFZ in relapsed or refractory myeloma: PX-171-003 (003) and PX-171-004 (004). Methods: CFZ was administered as an IV bolus of 20 mg/m2 on Days 1, 2, 8, 9, 15 and 16 of a 28-day cycle on both trials. Bone marrow samples, from an optional sub-study of both trials, were taken during screening and Day 2 (post-treatment) and sorted into CD138+ and CD138− cells. Proteasome activity was measured by an enzymatic assay using a fluorogenic substrate (LLVY-AMC) for the chymotrypsin-like (CT-L) activity and an active site ELISA (ProCISE) to quantitate levels of the CT-L subunits of the constitutive proteasome (Beta5) and immunoproteasome (LMP7) and the immunoproteasome subunit MECL1. Results: Whole blood samples from patients treated with CFZ showed inhibition of CT-L activity of ∼80+, similar to values obtained in Phase 1 studies. A total of 10 CD138+ screening samples, 6 from 004 and 4 from 003, and 9 post-dose samples, 5 from 004 and 4 from 003, were analyzed for proteasome levels and activity. In addition, 15 CD138−screening samples, 7 from 004 and 8 from 003, and 9 post-dose samples, 5 from 004 and 4 from 003, were analyzed. When compared to the average base-line activity, CFZ treatment resulted in 88% CT-L inhibition in CD-138+tumor cells from 004 patients (P = 0.0212 by unpaired t-test) and 59% CT-L inhibition in CD-138+ tumor cells from 003 patients (P = 0.25). Baseline CT-L activity in CD138+ tumor cells was 3-fold higher in 004 than 003, which includes a more heavily pre-treated patient population with greater prior exposure to BTZ. Higher specific enzymatic activity was due to increased levels of both constitutive and immunoproteasomes in tumor cells, where immunoproteasomes account for >75% of total cellular proteasomes. No differences between trials were seen in baseline CT-L activity from non-tumor (CD138−) cells. Inhibition in CD138− cells was 84% (P = 0.0380 and 42% (P = 0.38) in 004 and 003, respectively. Using ProCISE, we measured inhibition of LMP7 (66%), beta5 (48%) and MECL1 (64%) in CD138+ tumor cells from 004 patients. Three patients from 004 and one from 003 had both a screening and post-dose tumor cell samples available for analysis. Inhibition of CT-L activity was >80% in two of the 3 patients on 004; the third patient showed no proteasome inhibition by ProCISE and was unavailable for analysis by CT-L. CT-L activity in the CD138+ tumor cells in the 003 patient was not inhibited, however, inhibition was seen in non-tumor cells. Conclusions: CFZ inhibits the proteasome activity of myeloma cells in the bone marrow of relapsed and refractory myeloma patients. The levels of inhibition were similar to those measured in whole blood samples, supporting the use of the blood-based assay as a surrogate marker for proteasome inhibition in tumor cells. CFZ treatment resulted in inhibition of both CT-L subunits as well as additional subunits of the immunoproteasome in tumor cells. Reduced baseline activity in the more heavily pretreated 003 patients may reflect reduced tumor-dependency on the proteasome and may be related to prior treatment with BTZ in these patients. More samples are needed in order to make correlations between levels of proteasome inhibition in bone marrow tumor cells and prior therapies or response. These observations support further evaluation of proteasome activity and the effects of this promising new agent in primary tumors cells from myeloma patients. Disclosures: Trudel: Celgene: Honoraria, Speakers Bureau; Ortho Biotech: Honoraria. Lee:Proteolix, Inc.: Employment. Kirk:Proteolix, Inc.: Employment. Lonial:Celgene: Consultancy; Millennium: Consultancy, Research Funding; BMS: Consultancy; Novartis: Consultancy; Gloucester: Research Funding. Wang:Proteolix, Inc.: Research Funding. Kukreti:Celgene: Honoraria. Stewart:Genzyme, Celgene, Millenium, Proteolix: Honoraria; Takeda, Millenium: Research Funding; Takeda-Millenium, Celgene, Novartis, Amgen: Consultancy. Jagannath:Millennium: Honoraria, Membership on an entity's Board of Directors or advisory committees; Merck: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees. McDonagh:Proteolix: Research Funding. Zonder:Celgene: Speakers Bureau; Pfizer: Consultancy; Seattle Genetics, Inc.: Research Funding; Amgen: Consultancy; Millennium: Research Funding. Bennett:Proteolix: Employment.

Abstract Abstract 600 Background: Both MM and AL are plasma cell neoplasms. The underlying clone in both diseases appears to be different not only in terms of “tumor burden” but also in terms of their underlying biology. The overall “fitness” of patients with these two diseases is also different, with AL patients having more major organ dysfunction. Therapy for both diseases is directed at killing the underlying clone. ASCT is one method of reducing the clone size and thereby improving overall survival. Post-ASCT outcomes between the two diseases have never been formally compared. Methods: We compiled all patients with a diagnosis of AL or MM who received ASCT at the Mayo Clinic Rochester between June 1996 and January 2011 to compare outcomes. Patients were retrieved from two prospectively maintained clinical transplant data bases (M.A.G.). Differences between groups were compared using Fisher's exact and Wilcoxon tests. Survival was calculated using the method of Kaplan-Meier, and differences between survival outcomes were calculated by log rank. Cox regression modeling was done to determine how non-disease specific variables—i.e. age, time period of ASCT, number of prior regimens, time to ASCT from diagnosis and acquisition of complete response (CR)—affected outcomes. All statistical analyses were performed using JMP (SAS, NC) software. This study was approved by the Mayo IRB. Results: The data set was comprised of 454 patients with AL and 1116 patients with MM. There were significant differences between the two respective groups of patients in terms of number of prior regimens (0 vs 1, p<0.0001), time to ASCT (3.95 months vs 7.20 months, p<0.0001), intensity of conditioning regimen (non-attenuated in 69.4% vs 89.1%, p<0.0001), serum creatinine (1.1mg/dl vs 1mg/dl p<0.0001), creatinine clearance (72.5 ml/minute vs 80 ml/minute p<0.0001), albumin (2.61g/dl vs 3.50g/dl, p<0.0001) CRP (0.40mg/dl vs 0.63mg/dl p<0.0001), LDH (196 U/l vs 182U/l, p<0.0001), and bone marrow plasmacytosis at transplant (6% vs 9%, p<0.0001). Hematologic response rates were also significantly different between the groups, with higher overall hematologic response in the MM group (90.9% vs 79.5%, p<0.0001) and higher complete response (CR) rates (40.1% vs 29.4%, p<0.0001) in the AL group. With a median follow-up of surviving patients of 68 months, the respective median overall survival (OS) for the AL and MM patients was 113 and 59.5 months, p<0.0001. Notably, the 5-year OS of AL and MM patients achieving CR were 91.4% and 57.7%, respectively, p<0.0001. If only those patients who were transplanted within 1 year of their diagnosis are included in the analysis, the respective 5-year OS of AL and MM patients achieving CR were 90.4% and 61.3%, p<0.0001 (Figure 1). To correct for imbalances in non-disease specific parameters, 3 multivariate analyses were performed using: 1) all patients; 2) only those achieving CR; and 3) only those who achieved a CR and were transplanted within 12 months of their diagnosis (Table 1). Among those patients achieving CR, MM patients had nearly a 4-fold risk of death as compared to patients with AL. Conclusion: Although ASCT is not available to all patients with either AL or MM, there is a significant difference in outcomes based on the diagnosis. Patients with AL who undergo ASCT enjoy a superior survival as compared MM patients undergoing the same procedure. This difference is most notable among those patients who achieve CR suggesting very different plasma cell biology between the two diseases. Disclosures: No relevant conflicts of interest to declare.