Citations

Abstract Abstract 863 Background: Patients with MM who have progressed after multiple novel agents have limited treatment options. Pomalidomide (CC4047) is the newest immunomodulatory (IMiD) agent. Pom/dex using a dose of 2 mg/day has demonstrated response rates (≥PR) of 63% in relapsed MM (Lacy, JCO 2009, 27:5008-5014) and 32% in a lenalidomide-refractory cohort (Lacy, Leukemia, in press). The maximum tolerated dose has been determined to be 4 mg/day for 21 of 28 days (Richardson, ASH, 2009), We opened two sequential phase II trials using the Pom/dex regimen at differing doses to study the efficacy of this regimen in patients who have failed both lenalidomide and bortezomib. Methods: Patients refractory to both lenalidomide and bortezomib therapy; defined as relapsing on or within 60 days of stopping each regimen, were enrolled. Pomalidomide was given orally 2 mg daily (Cohort A) or 4mg daily (Cohort B) on days 1–28 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 DVT prophylaxis. Results: 35 patients with relapsed and resistant/refractory to both lenalidomide and bortezomib were enrolled in each cohort. The median age was 62 years (range, 39–77) in Cohort A and 61 (range, 45–77) years in Cohort B. The median time from diagnosis to enrollment was 57 months for Cohort A (range 12–249) and 72 months(range, 13–183) for Cohort B. 15 patients had high risk molecular markers in Cohort A and 16 in Cohort B. The median number of prior regimens was 6 in both groups. The median (range) duration on treatment was 5(1-13) and 2(0-6) cycles in cohorts A and B respectively. Toxicity at least possibly attributed to drug consisted primarily of myelosuppression: grade 3/4 neutropenia (37% Cohort A vs. 55% Cohort B); grade 3/4 thrombocytopenia (11% Cohort A vs. 13% Cohort B); and grade 3/4 anemia (9% Cohort A vs. 16% Cohort B). Grade 3/4 non-hematologic toxicities occurred in 23% Cohort A vs. 13% Cohort B. Grade 1 or 2 fatigue was the most common non-hematologic toxicity seen in 43% Cohort A vs. 52% Cohort B. Grade 1 or 2 neuropathy occurred in 17% Cohort A vs. 16% Cohort B. Other non-hematologic toxicities occurring in <5% included pneumonitis, hyperglycemia, renal failure, thrombosis. One patient in cohort B had grade 4 hepatitis. Confirmed responses in Cohort A consisted of VGPR 14%, PR 11%, and MR 24% (ORR 49%, 95% CI: 31–66), and responses in Cohort B consisted of VGPR 9%, PR 20%, and MR 12% (ORR 40%, 95% CI: 23–58). The median follow-up on alive patients was 7.5 months, and 3 months in Cohorts A and B, respectively. The median PFS in cohorts A and B are respectively 6.4 months (95% CI: 4.7-NR) and 3.3 months (95% CI: 2.3-NR). Conclusions: Pom/dex is remarkably active and well tolerated in this heavily pre-treated population of dual bortezomib/lenalidomide-refractory MM patients. The majority of patients have not progressed and objective responses (MR or better) are seen in 40–49%. This study confirms therapeutic benefit for Pom/dex in patients relapsing after other novel therapies. These studies do not show an advantage for the 4 mg/day on days 1–28 of each 28 day cycle did not show an advantage over the 2 mg/day on days 1–28 of each 28 day cycle. Disclosures: Lacy: Celgene: Research Funding. Gertz:Celgene: Honoraria; Millennium: Honoraria, Membership on an entity's Board of Directors or advisory committees. 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. Fonseca:Genzyme: Consultancy; Medtronic: Consultancy; BMS: Consultancy; AMGEN: Consultancy; Otsuka: Consultancy; Celegene: Consultancy, Research Funding; Intellikine: Consultancy; Cylene: Research Funding; Onyx: Research Funding; FISH probes prognostication in myeloma: Patents & Royalties. Bergsagel:Celgene: Consultancy; Centocor: Consultancy; Genentech: Consultancy; Amgen: Consultancy; Novartis: Consultancy. Stewart:Celgene: Honoraria.

Abstract Abstract 3963 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 November 2010, we opened 5 sequential phase 2 trials using the pomalidomide at differing doses with weekly dexamethasone (Pom/dex) regimen to study the efficacy of this regimen. Methods: The five cohorts consisted of: Cohort 1 (N=60): relapsed MM with 1–3 prior regimens, 2 mg dose; Cohort 2 (N=34): lenalidomide refractory, 2 mg dose; Cohort 3 (N=35): bortezomib/lenalidomide refractory, 2 mg dose; Cohort 4 (N=35): bortezomib/lenalidomide refractory, 4 mg dose; and Cohort 5 (N=60) lenalidomide refractory, 1–3 prior regimens, 4 mg dose. Pomalidomide was given orally 2 mg daily or 4mg daily on days 1–28 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 DVT prophylaxis or full dose anticoagulation. Results: A total of 225 patients were enrolled across all 5 cohorts. One patient was ineligible and excluded from analysis. The median age was 63 years (32.0–88.0). The median time since diagnosis was 53 months. Forty percent had high-risk molecular markers. Eighty-nine percent had received previous IMIDs including thalidomide (53%) and lenalidomide (81%). Sixty-two percent had previous bortezomib and 73% had prior transplant. The median follow-up is 12.6 months, but varies from 9.4 months for the most recent cohort to 30 months for the first cohort. Sixty-nine percent are alive and 30% remain progression free. Toxicities ≥ grade 3 are shown in table 1 and patient outcomes are shown in Table 2. Conclusions: Pom/dex is remarkably active and well tolerated even in heavily pretreated patients. Responses are durable. Response rates and toxicity are similar between the 2 mg and 4 mg doses. Disclosures: Lacy: Celgene: Research Funding. Fonseca:Consulting:Genzyme, Medtronic, BMS, Amgen, Otsuka, Celgene, Intellikine, Lilly Research Support: Cylene, Onyz, Celgene: Consultancy, Research Funding.

Abstract Abstract 3980 Background: Nearly half of patients with multiple myeloma (MM) are over 70 years at the time of diagnosis. While the survival of patients with myeloma has improved in the last decade, several studies have suggested no significant change for the elderly patients. These patients often have other comorbidities and are less likely to tolerate standard treatment approaches. We retrospectively studied the treatment patterns, outcomes, and prognostic factors in patients over 75 years of age. PATIENTS AND METHODS: We identified 212 patients who were older than 75 years from among 1545 patients seen at the Mayo Clinic within 90 days of diagnosis during 1999 to 2008. We only included 139 patients in whom complete treatment details were available. RESULTS: The median age was 80 years (range: 76–94) with 20 (14%) patients older than 85 years; 79 (57%) were male. Thirty-five patients (25%) had a history or coexistence of one or more malignancies. Chromosome analysis and FISH were performed in 65% and 22% respectively. Abnormal cytogenetics were seen in 30 (33%) of the 90 tested patients. The median survival of the 139 elderly patients was 27 months (95% CI: 20∼35) compared to 62 months (56∼68) for 1,290 patients ≤ 75 years of age seen during the same period. Sixty-nine (50%) patients received one or more novel agents (thalidomide, lenalidomide, pomalidomide, bortezomib) and showed longer median survival (40 months vs 13 months) compared with those not receiving these agents (p=0.0008). Age over 85, initial poor performance score > 1, thrombocytopenia, elevated serum LDH or beta2-microglobulin, response more than stable disease to first therapy resulted in inferior survival. Among them, only performance status had the persistent significance in multivariate analysis. CONCLUSION: Older patients receiving newer therapies appear to have a better outcome, which is still lagging behind the younger patients. A poor performance score at diagnosis predicts for eventual poor outcome. Disclosures: No relevant conflicts of interest to declare.

Abstract Abstract 987 Background: IMiD® compounds are effective in immunoglobulin light-chain amyloidosis (AL), a systemic plasma cell disorder related to multiple myeloma (MM). Pomalidomide is a new IMiD® compound. Methods: Persons with symptomatic, biopsy-proved, previously-treated AL were eligible for treatment with pomalidomide if they had measurable hematologic disease, ECOG PS≥2, adequate hematologic reserve and creatinine ≤2.5 mg/dL. Pomalidomide, 2 mg/d, and dexamethasone, 40 mg/w, were given orally along with low-dose aspirin. Dose-escalation to 4 mg/d was allowed for non-responders. Exclusion-criteria were uncontrolled infection, cancer, NYHA classification >II, serum troponin-T >0.1 ng/mL, ≥grade-3 neuropathy, thrombosis or other AL therapy within 2 weeks of enrollment. 31 subjects enrolled, but only 29 are evaluble for toxicity and response due to recent enrollment. Results: Median age was 66 y (range, 52 82 y); 19 were male. Median time from diagnosis to study-entry was 36 mo (range, 0.9–104.1 mo). 24 had cardiac involvement, 10, renal involvement and 8, nerve involvement. Cardiac biomarker staging was: I, N=3, II, 21, and III, N=7. Subjects were extensively pretreated: 28 received an alkylator (including an autotransplant in 13), 15, prior lenalidomide or thalidomide and 12, prior bortezomib. 193 cycles of pomalidomide were given to 29 subjects. 11 subjects had protocol-specified dose-increases (no response) and 16, dose-reductions (AEs). 20 subjects had dexamethasone dose-reductions. ≥Grade-3 AE's ≥possibly attributed to therapy occurred in 21 subjects. 7 of these subjects had only hematologic AE's. Neutropenia was the most common severe AE (N=10); severe thrombocytopenia occurred in 2 subjects. Other grade-3/-4 AEs included infection/fever (N=3); fatigue (N=4), and pleural effusion, ascites/edema, and edema each in one patient. 1 subject each had dyspnea, increased creatinine, thrombosis, muscle weakness, atrial tachycardia, and diarrhea. There were 2 episodes of syncope attributed to AL rather than therapy. A subject died 5 d after beginning therapy presumably from cardiac AL. As of 7/27/010, median time on-study is 8.4 mo (range, 0.2–16.2 mo). 18 subjects discontinued therapy for: progression/death (N=9); consent withdrawal (N=4), AE (N=3) and physician choice (N=2). Overall hematologic response rate (N=29) is 38% (95% CI, 20–58%) There were 8 PRs and 3 VGPRs including 4 PRs and 2 VGPRs among 14 subjects failing prior lenalidomide and/or thalidomide. 3 subjects had confirmed organ responses (2 heart and 1 kidney) and 4 unconfirmed organ responses. 1 y survival and PFS are 77% (95% CI, 60–98) and 56% (95% CI, 36–85). Conclusion: These data suggest that pomalidomide could provide a safe and effective therapy in previously-treated persons with AL including those failing lenalidomide and/or thalidomide. Disclosures: Dispenzieri: Celgene: Honoraria, Research Funding; Binding Site: Honoraria. Off Label Use: Non-FDA approved indication. Gertz:Celgene: Honoraria. Kumar:Celgene: Consultancy, Research Funding; Millennium: Research Funding; Merck: Consultancy, Research Funding; Novartis: Research Funding; Genzyme: Consultancy, Research Funding; Cephalon: Research Funding. Fonseca:Amgen: Consultancy; Bristol-Myers Squibb: Consultancy; Celgene: Consultancy, Research Funding; Genzyme: Consultancy; Onyx: Research Funding; Otsuka: Consultancy; Medtronic: Consultancy. Bergsagel:Celgene: Consultancy; Centocor: Consultancy; Genentech: Consultancy; Amgen: Consultancy; Novartis: Consultancy. Stewart:Millennium: Consultancy; Celgene: Honoraria. Lacy:Celgene: Research Funding.

Abstract Introduction: Localized immunoglobulin light chain amyloidosis (LAL) is a rare disease. Systematic data regarding its presentation, management and patient outcomes are limited to small case series. Our objective was to systematically describe the Mayo clinic experience of patients with LAL. Methods: We retrospectively reviewed clinical records of 403 patients with biopsy proven localized amyloidosis seen at the Mayo Clinic between 1969-2014. Median follow-up for survival and progression were 72 months and 39 months, respectively Results: OF 5551 patients with light chain amyloidosis seen at the Mayo clinic during the study period, 403 (7%) had LAL. Median age at diagnosis was 60 years (range, 13-93) and 51% of them were male. Sites involved included: urothelial (bladder, ureter, renal pelvis), 75 (19%), larynx, 51 (13%), lung parenchyma, 42 (11%), skin, 44 (11%), synovial tissue 36 (9%), tracheobronchial, 31 (8%), gastrointestinal tract, 30 (8%), seminal vesicles, 22 (6%), eyes, 23 (6%), pharynx 22 (6%) and other 24 (6%). Typing was performed in 178 (45%) cases. A monoclonal protein was detected in 23 of 351 (7%) evaluated cases, 5 of which had different light restriction from that of LAL. Thirty one (8%) patients had a co-existent autoimmune disease. No patients progressed to systemic AL. Of 403, 109 (27%) were observed or received supportive care only and 241 (60%) underwent local removal of the amyloid deposits. Sixty-four (16%) patients required repeated interventions (median 1, range 1-4, upper decile requiring 4 interventions) for progressive disease. The most common sites requiring repeated interventions were: urothelial (33%), laryngeal (19%) and tracheobronchial (8%). Ten year overall survival (OS) and progression free survival were 79% and 61%, respectively and there was no difference according to site of involvement. Of the 70 patients that died during the follow-up period, cause of death was known for 29 and death was attributed to LAL in only 2 cases. Conclusions: In the largest series of patients with LAL reported so far we demonstrated that LAL has an excellent prognosis but can sometimes be associated with significant morbidity. Although our study was limited by incomplete typing in 55% of cases, it appears that true LAL does not "progress" to systemic amyloidosis. However, systemic amyloidosis can frequently involve organs typical involved only in LAL;, therefore a complete work-up for systemic disease should be performed in all patients with LAL. Treatment usually involves local excision for symptom palliation. In 16% of cases, repeated interventions for relapse/progression were required and as a result, follow-up is recommended, especially for cases involving the urothelial and upper respiratory tract. Disclosures Kumar: Skyline, Noxxon: Honoraria; Celgene, Millennium, Onyx, Novartis, Janssen, Sanofi: Research Funding; Celgene, Millennium, Onyx, Janssen, Noxxon, Sanofi, BMS, Skyline: Consultancy.

Abstract Background: Lenalidomide with dexamethasone (Rd) is a standard of care for patients with previously untreated multiple myeloma. SWOG S0777, a randomized phase III trial, has compared Rd with bortezomib, lenalidomide and dexamethasone (VRd). The primary end point is progression-free survival (PFS) using a pre-specified one-sided stratified log rank test at a significance level of 0.02. The stratification factors are International Staging System (ISS) stage (I, II or III) and intent to transplant (yes or no), a total of 6 strata. Overall response rate (ORR), overall survival (OS) and safety are secondary end points. Methods: This analysis includes 474 patients evaluable for survival endpoints: 232 patients were randomized to Rd and 242 patients to VRd. Rd patients received lenalidomide 25 mg/day on days 1-21 and dexamethasone 40 mg/day on days 1, 8, 15 and 22 of a 28-day cycle. VRd patients received lenalidomide 25 mg/day on days 1-14 and dexamethasone 20/mg/day on days 1, 2, 4, 5, 8, 9, 11 and 12 plus bortezomib 1.3 mg/m2 IV push on days 1, 4, 8 and 11 of a 21-day cycle. All patients received aspirin 325 mg/day and VRd patients received HSV prophylaxis per institutional standard. Induction was six 28-day cycles of Rd and eight 21-day cycles of VRd followed by Rd maintenance for all patients until progression, unacceptable toxicity or withdrawal of consent. Initial analyses utilized the pre-specified one-sided stratified log rank test. Results: Data are presented for VRd followed by Rd throughout. Between 2008 and 2012, 525 patients from 48 institutions were randomized. Fifty-one patients, 29 randomized to Rd and 22 randomized to RVd, were ineligible for the following reasons: missing, insufficient or early or late baseline labs (40); not meeting requirements of measurable disease (6); inadequate marrow function (1); inadequate creatinine clearance (1); prior malignancy (1); prior therapy (1); and more than 2 weeks of prior steroid therapy (1). The pre-specified significance level of 0.02 was reached in the log rank testing. The stratified hazard ratio (HR) was 0.742 (96% Wald confidence interval: 0.579, 0.951), and the one-sided stratified log rank p-value for PFS (VRd vs. Rd) was 0.0066. The OS was improved for VRd vs. Rd with HR = 0.666; two-sided log-rank p-value = 0.0114. The PFS and OS survival charts are displayed below. Median PFS was 43 months (VRd) versus 31 months (Rd). Median OS was not reached (VRd) versus 63 months (Rd). Patient characteristics were well-matched between VRd and Rd with the exception of fewer women (37% vs. 47%: P = 0.033) and fewer older patients (≥ 65 years 38% vs. 48%: P = 0.042) receiving VRd. With univariate Cox regression analysis correlates of better PFS/OS were: use of VRd (HR 0.72/0.65; P = 0.006); hemogoblin ≥10 g/dl (HR 1.17/1.43; P = 0.2/0.026) and lower ISS disease stage (HR 1.35/1.98; P = 0.014/< 0.001). The ORR for VRd was 71.07% versus 63.79% for Rd. The adverse events by CTC category and toxicity category were fairly well balanced. The most common hematologic adverse events (≥ Grade 3 and at least possibly attributable to therapy) were low hemoglobin (RVd=13%; Rd=16%), leukopenia (RVd=14%; Rd=16%), lymphopenia (RVd=23%; Rd=18%), neutropenia (RVd=19%; Rd=21%), and thrombocytopenia (RVd=18%; Rd=14%). The most common non-hematologic adverse events (≥ Grade 3 and at least possibly attributable to therapy) were: fatigue (RVd=16%; Rd=14%), sensory neuropathy (RVd=23%; Rd=3%), hyperglycemia (RVd=7%; Rd=11%), thrombosis/embolism (RVd=8%; Rd=9%), hypokalemia (RVd=9%; Rd=6%), muscle weakness (RVd=7%; Rd=4%), diarrhea (RVd=8%; Rd=2%), and dehydration (RVd=8%; Rd=2%). As expected ≥ Grade 3 neuropathy was more frequent with VRd (24% vs. 5%: P < 0.0001). Sixteen patients experienced a second primary malignancy, 7 (3%) on VRd and 9 (4%) on Rd. Conclusion: The addition of bortezomib to lenalidomide dexamethasone for induction therapy in previously untreated myeloma results in a statistically significant and clinically meaningful improvement in PFS as well as better OS. VRd had an acceptable safety and tolerability profile despite increased neurotoxicity and represents a potential new standard of care. Support: NIH/NCI/NCTN grants CA180888, CA180819, CA180821, CA180820; and in part by Millennium Pharmaceuticals, Inc., The Takeda Oncology Company, for provision of study drug. Figure 1. Figure 1. Figure 2. Figure 2. Disclosures Durie: Johnson & Johnson: Consultancy; Takeda: Consultancy; Onyx: Consultancy; Celgene: Consultancy. Abidi:Millennium: Research Funding. Epstein:University of Arkansas for Medical Sciences: Employment. Reu:Takeda/Millennium: Research Funding; Novartis: Research Funding; Celgene: Research Funding. Orlowski:BioTheryX, Inc.: Membership on an entity's Board of Directors or advisory committees; Janssen Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Research Funding; Spectrum Pharmaceuticals: Research Funding; Onyx Pharmaceuticals: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Millennium Pharmaceuticals: Consultancy, Research Funding; Acetylon: Membership on an entity's Board of Directors or advisory committees; Genentech: Consultancy; Forma Therapeutics: Consultancy; Array BioPharma: Consultancy, Research Funding. Barlogie:Dana Farber Cancer Institute: Other: Travel Stipend; International Workshop on Waldenström's Macroglobulinemia: Other: Travel Stipend; ComtecMed- World Congress on Controversies in Hematology: Other: Travel Stipend; European School of Haematology- International Conference on Multiple Myeloma: Other: Travel Stipend; Celgene: Consultancy, Research Funding; Millennium: Consultancy, Research Funding; Myeloma Health, LLC: Patents & Royalties: Co-inventor of patents and patent applications related to use of GEP in cancer medicine licensed to Myeloma Health, LLC; Multiple Myeloma Research Foundation: Other: Travel Stipend.

Abstract Abstract 1814 Multiple myeloma (MM) is an incurable hematologic disorder characterized by the accumulation of plasma cells (PCs) in the bone marrow (BM). Like normal B cells and PCs, MM cells express a distinctive immunoglobulin (Ig) molecular fingerprint resulting from heavy and light chain gene rearrangements and unique mutations introduced by the somatic hypermutation (SHM) process. Detailed examination of the Ig molecule may offer insight into the etiology of B cell malignancies as well as the ontogeny of malignant transformation and ongoing genetic evolution. Because prior studies of the Ig fingerprint of MM cells have been limited in size and scope, our current understanding of MM Ig repertoire is minimal. We used massively parallel sequencing of normal and malignant PCs to interrogate: 1) DNA versus RNA (cDNA) as starting material for studies of Ig repertoire; 2) the Ig repertoire of normal and malignant PCs; and 3) intraclonal heterogeneity in MM. Bone marrow PCs (BMPCs) from an untreated MM patient and from a normal control subject were isolated by magnetic bead separation. DNA and RNA were isolated from purified cells and amplified in a multiplex PCR reaction with primers designed to capture the entire IGHV region including the heavy chain complementarity determining region 3 (HCDR3) necessary for defining clonal cells. Using Roche 454 GS-FLX Titanium chemistry and a GS FLX Titanium Genome Sequencer, over 30,000 sequence reads were obtained from each sample. Following a detailed algorithm to minimize Taq and sequencing related errors and removal of non-Ig or non-productive Ig sequences, the resulting sequences were grouped based on HCDR3 amino acid identity. Each unique HCDR3 represented one member of the repertoire and all the sequences with the same HCDR3 defined the clone size. This measurement showed that there was nearly a five-fold higher level of unique HCDR3s in normal BMPCs when the starting PCR template was DNA vs. cDNA. Thus, DNA is clearly a better starting template for repertoire analysis using deep sequencing methods. Thorough analysis of the MM DNA sample identified PCs expressing 37 different IGHV genes, and predictably, the vast majority of sequence reads (83%) had exact nucleotide identity in the IGHV and HCDR3 region (IGHV3-74 with 18 mutations in the IGHV region) thereby defining the dominant MM clone. There were also ∼5000 additional sequences that either shared an identical HCDR3 region but varied within the IGHV3-74 gene sequence (n=3975) or were identical within the IGHV3-74 sequence yet varied within the HCDR3 (n=862). These sequences were further analyzed, with sequences not present 10 or more times or not found in both the 5' and 3' directions eliminated from further scrutiny. This process revealed a total of 64 putative subclones with single point mutations in the IGHV or HCDR3 region (10–56 copies of each unique sequence representing a total of 1583 clonally related sequences). When we used a more stringent subclone frequency of ≥0.1%, 22 subclones remained. Of note, conventional Ig repertoire analysis would require sequencing ≥1000 colonies to detect MM subclones present at this frequency. Finally, 11 subclones displayed a significant number of IGHV gene nucleotide differences from the dominant MM clone despite exhibiting an identical HCDR3 region. Notably, a number of these distinguishing IGHV gene mutations are silent and thus may preserve the antigenic specificity of these clonally related cells. These subclones failed our frequency criteria but the type and quality of deviations from the clonal sequence suggest that they are not artifact and warrant further investigation. Notably, all of the putative subclones were also found in the MM cDNA cohort providing further evidence as genuine subclones. The very large number of identical MM clonal sequences is consistent with the idea that MM is a post germinal center malignancy that can no longer undergo SHM. However, we present clear evidence of MM-related subclones albeit relatively small in number. The subclone sequence deviations discovered may reflect on-going genetic evolution independent of the formal SHM mechanism. Alternatively, these subclones may indeed reflect “sister” cells generated during the original germinal center reaction that resulted in the malignant clone. In summary, our studies demonstrate the extraordinary potential of this methodology to track clonal evolution in MM and its precursor conditions over time. Disclosures: No relevant conflicts of interest to declare.

Abstract Background WM remains an incurable cancer despite recent advances. While a phase II trial has demonstrated efficacy of dexamethasone, rituximab and cyclophosphamide (DRC) in the treatment-naïve (TN) patients, this regimen has not been studied systematically in the relapsed/refractory (R/R) setting. Recent data has suggested the MYD88mutation status in WM patients can serve as a predictive marker with therapies such as ibrutinib. We examined the efficacy and tolerability of up to 6 cycles of DRC, with focus on R/R population and activity of this regimen with respect to the patients' MYD88L265Pstatus. Methods Records of WM patients seen consecutively at Mayo Clinic campuses in Rochester, Arizona and Florida from 01/2007 to 12/2014 were reviewed. MYD88L265P status, as assessed by AS-PCR, was recorded when available. Data obtained from symptomatic patients treated with DRC (dexamethasone 20 mg intravenously followed by rituximab 375 mg/m2 intravenously on day 1 and cyclophosphamide 100 mg/m2 orally bid on days 1 to 5) were analyzed. Time-to-event analyses were performed from DRC therapy using the Kaplan-Meier method. We used the Consensus response criteria (6th International Workshop). Results Of 100 symptomatic patients who received DRC, 50 had R/R WM (40% refractory) and 50 were TN. Table 1 shows the patients' baseline characteristics. In the R/R population, DRC was 2nd line (range 2-8) therapy in 58% of patients. The median IgM levels declined from 3,870 mg/dL to 1,846 mg/dL (p=0.0001) at best response. Median follow-up from DRC was 51 months (95% CI: 38-55). The median time-to-best response was 6.8 (0.5-28) months. Overall response rate (ORR) was 87% [VGPR 4%, PR 64%, MR 19%]. Four patients (9%) achieved SD and 2 patients (4%) had PD. Of the sixteen deaths (32%) noted at time of analysis, 11 were related to progressive disease. The median disease-specific survival (DSS) from DRC was not reached (NR) (95% CI: NR-NR). The median progression-free survival (PFS) and time-to-next-therapy (TTNT) were 32 months (95% CI: 15-51) and 50 months (95% CI: 35-60), respectively. In contrast, in the TN patients the median IgM levels declined from 4,130 mg/dL to 1,250 mg/dL (p=0.0001) at best response; median time to best response was 11 (0.6-47) months; median follow-up from DRC was 30 months (95% CI: 21-36). ORR was 96% [VGPR 17% (n=8), PR 70% (n=32), MR 9% (n=4)]. Of the 7 deaths (14%) at time of analysis, 4 were related to WM progression. Median DSS from DRC was NR (95% CI: NR-NR); median PFS and TTNT were 34 months (95% CI: 23-NR) and NR (95% CI: 37-NR), respectively. Among 29 genotyped patients in whom MYD88 mutation status was available, MYD88L265P was present in 25 patients (8 of 10 TN and 17 of 19 R/R patients). The response rates and the time-to-event outcomes were similar in the MYD88L265P and wild-type patients. Grade ≥3 adverse effects included neutropenia (20%), thrombocytopenia (7%) and infections (3%). Conclusions Similar to the frontline setting, DRC is an active and well-tolerated salvage regimen. In contrast to ibrutinib, DRC offers a less expensive, limited-duration treatment option, with preliminary data suggesting activity independent of patients' MYD88 mutation status. Disclosures Ailawadhi: Pharmacyclics: Consultancy; Novartis: Consultancy; Amgen Inc: Consultancy; Takeda Oncology: Consultancy. Kumar:Glycomimetics: Consultancy; Sanofi: Consultancy, Research Funding; Noxxon Pharma: Consultancy, Research Funding; Onyx: Consultancy, Research Funding; AbbVie: Research Funding; Celgene: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Millennium: Consultancy, Research Funding; Kesios: Consultancy; Array BioPharma: Consultancy, Research Funding; Skyline: Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: Consultancy. Dispenzieri:Jannsen: Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; pfizer: Research Funding; Celgene: Research Funding; Prothena: Membership on an entity's Board of Directors or advisory committees; Alnylam: Research Funding; GSK: Membership on an entity's Board of Directors or advisory committees. Ansell:BMS, Seattle Genetics, Merck, Celldex and Affimed: Research Funding. Kapoor:Amgen: Research Funding; Celgene: Research Funding; Takeda: Research Funding.

Abstract Abstract 370 Background: Light chain (AL) amyloidosis is characterized by the deposition of amyloid derived from immunoglobulin light chains in various organs. Autologous peripheral blood stem cell transplantation (SCT) is a commonly used and effective treatment for AL. For patients (pts) undergoing this procedure, a proportion of pts receive treatment similar to induction therapy employed in pts with myeloma undergoing SCT. However, the significance of induction therapy and its impact on the overall survival (OS) in AL is unknown. We conducted this study to ascertain the role of pre-SCT therapy on the post-transplant outcomes in AL. Patients and methods: 435 pts with AL who underwent SCT at our institution between March 1996 and May 2010 form the study group. Groups were compared using Fisher's exact test or t-test, and survival was calculated using Kaplan Meier method. Survival curves were compared using log rank test. Result: The median (range) age of pts at the time of SCT was 57.4 years (26-75); 260 (60%) were males. The median (range) duration from AL diagnosis to SCT was 4 mos (1-87), and 284 (65%) pts were alive at the time of analysis. Melphalan 200/m2 (271 pts) or Mel/TBI (17 pts) was used for conditioning in 66% pts, whereas the remaining one-third had reduced doses of melphalan (100-160 mg/m2). The median OS for pts that received pre-SCT therapy (N=286) compared with those who did not (N=149) was 94.7 and 96.5 months, respectively (P=0.6) (Fig 1). Among the group of pts who underwent pre-SCT therapy and were evaluable for response, the median OS for those with a hematologic response (N=42) and no hematologic response (N=42) was 82.1 and 51 months (P=0.2), respectively (Fig 2). Conclusion: Our study demonstrates no difference in the OS of AL patients who received a pre-SCT therapy compared with those who received a SCT after their diagnosis of AL. In patients receiving pre-SCT therapy, there was a trend towards reduced OS among those with no hematologic response to pre-transplant therapy, but this difference was not significant. Disclosure: Kumar: Celgene: Consultancy, Research Funding; Millennium: Research Funding; Merck: Consultancy, Research Funding; Novartis: Research Funding; Genzyme: Consultancy, Research Funding; Cephalon: Research Funding. Dispenzieri:Celgene: Honoraria, Research Funding; Binding Site: Honoraria.

Abstract Abstract 3554 Introduction: The role of SCT in the management of Ig light chain (AL) amyloidosis remains undefined. Patients: We report 422 patients (Table 1) who received SCT for AL amyloidosis to compare outcomes of patients treated before January 2006 with those of patients treated from January 2006 until December 1, 2009. Results: Day 100 all-cause mortality decreased over this time period from 12% to 7% (P=.09) figure 1. Survival at 2 years increased from 78% to 82%. Figure 2 The major determinants of early mortality (before day 100) were the presence of cardiac involvement with amyloid and increased levels of cardiac biomarkers, lower serum albumin, higher serum creatinine, and a higher number of organs involved. (Table 2) On multivariate survival analysis, higher levels of serum troponin T and N-terminal pro–brain natriuretic peptide were the only predictors of early mortality after SCT. Conclusion: Improved supportive care and refined patient selection has improved the safety margin for patients undergoing SCT; short-term mortality showed a more than 40% decrease after 2005. Recognition of this decrease in mortality is important for physicians caring for these patients as they weigh the pros and cons of SCT vs novel agent-based treatment in management of amyloidosis. Disclosures: Gertz: Celgene: Honoraria; Millenium: Honoraria, Membership on an entity's Board of Directors or advisory committees. 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.