ALBERT

Description: INTRODUCTION: Multiple myeloma (MM) is a biologically and clinically heterogeneous disease. Different recurrent driver genomic events have been reported, but to date no unifying feature has been identified in MM evolution. The recent interest in signatures of mutational processes through analysis of whole-exome sequencing data has led to initial insights into what generates MM mutational repertoire (Bolli et al, Nat Com 2014). Here, taking advantage of the increased power provided by whole genome sequencing (WGS), we analyzed 22 paired samples from 11 patients first at the smoldering (SMM)/MGUS stage and subsequently at the time of progression to symptomatic MM to gain a deeper understanding of the full landscape of mutational processes operative in MM, especially during their evolution over time. MATERIAL AND METHODS: DNA from bone marrow CD138+ cells underwent WGS along with a matched normal sample using HiSeq X Ten machines (Illumina, Inc.). Mutational signature extraction was performed running non-negative matrix factorization (NMF) as previously described (Alexandrov et al, Nature 2013). RESULTS: We have observed and utilized a median number of 5780 (range 2599-7760) substitutions per patient at the asymptomatic stage and 5954 (ranges 2824-8227) at progression to MM stage to extract mutational signatures. NMF extracted 5 main signatures (http://cancer.sanger.ac.uk/cosmic/signatures). Specifically, APOBEC- (signature #2) and age-related signatures (signatures #1 and #5) accounted for 13% (1-21%) and 23% (3.2-40%) of all substitutions, respectively. In addition, we found two known signatures that were not implicated in MM so far: non-canonical AID (Signature #9), contributing to 28% of all substitutions (17-55%); and signature #8, accounting for 28% of all substitutions (13-45%) and pertaining to a yet unknown mutational process. Finally, the fifth signature did not match any of the previously described ones, representing a potential novel process which we defined as MM-1 (7%, range (1-16%). Interestingly, we found a differential contribution of processes in non-coding and intronic regions where AID was more prevalent, while exonic regions where APOBEC and age signatures were more prevalent. In intronic regions we found widespread regions of kataegis (9/11 patients), reflective of localized hypermutation. In our patients, kataegis was associated with rearrangements in 60% of cases, and was present in both the SMM and MM sample in 84% of cases, suggestive of an early event during tumor development. Contrary to what is observed in solid cancers, APOBEC signature was only responsible for 25% of kataegis variants, vs 70% for AID, suggesting a causative role of aberrant AID activity in shaping the early mutational repertoire of neoplastic plasma cells. To confirm this, we looked at serial samples in our cohort. While the percent contribution of each signature varied in each patient, confirming genomic heterogeneity of MM, it did not change when paired SMM and MM samples from the same patient were compared. This shows that mutational processes required for the development of symptomatic MM act early, and have been already operative at the SMM stage. However, by clustering substitutions as clonal (early variants present at the time of tumor initiation) or subclonal (late variants arisen closer to the time of sampling) using a Bayesian hierarchical Dirichlet process (Bolli et al, Nature Comms 2014), we could analyze processes operative before SMM was diagnosed. NMF analysis of these clusters reported striking differences. Specifically, AID and age were the predominant mutational processes in early substitutions in all patients, contributing to a median of 35% (25-54%) and 30% (15-43%) of variants respectively. Conversely the contribution of AID was minimal among late substitutions (5%, 1-22%), where instead APOBEC, Signature #8 and MM-1 activity was prominent [19% (1-43), 38% (8-73%), 16% (2-50%) respectively]. CONCLUSION: WGS data allowed the identification of mutational processes operative well before MM becomes clinically evident. Our observation that all samples have signs of aberrant AID at the time of tumor initiation supports a unifying model where MM precursors are initially transformed with the contribution of AID, providing a fertile ground for other later processes (i.e APOBEC and signature #8) to act and shape the final genomic landscape of overt multiple myeloma. Disclosures No relevant conflicts of interest to declare.

Description: Introduction : Daratumumab (DARA) is a human, CD38-targeted, IgGκ monoclonal antibody. In the CASTOR study, D-Vd reduced the risk of disease progression or death by 68% and induced higher rates of deeper responses vs Vd in relapsed/refractory (RR) MM pts (Spencer, A. ASH 2017. Abs. 3145). Overall, in phase 3 studies in RRMM and newly diagnosed MM, DARA-based regimens reduced disease progression or death risk by ≥50%, doubled complete response (CR) rates, and tripled minimal residual disease (MRD)-negative rates. While progression-free survival (PFS) benefits of D-Vd vs Vd were observed regardless of the number of prior lines (PLs) of therapy, the benefit was most pronounced in pts receiving 1 PL of therapy. Here, we examine updated (2 y after interim analysis) efficacy and safety of D-Vd vs Vd in CASTOR, with a primary focus on pts with 1 PL of therapy. Method: Pts in CASTOR were randomized to receive 8 cycles (21 d/cycle) of V (1.3 mg/m2, SC) on Days 1, 4, 8, and 11 and dexamethasone (20 mg, PO or IV) on Days 1, 2, 4, 5, 8, 9, 11, and 12 with or without DARA (16 mg/kg, IV) given weekly for Cycles 1-3, Q3W for Cycles 4-8, and Q4W thereafter. Cytogenetic risk was evaluated centrally by next generation sequencing; high risk was defined as having t(4;14), t(14;16), and/or del17p abnormalities. MRD was assessed at the time of suspected CR and at 6 and 12 mo following the first treatment dose, and an additional MRD evaluation was required every 12 mo post-CR. MRD was evaluated using clonoSEQ® V2.0 (Adaptive Biotechnologies, Seattle, WA). Sustained MRD negativity was defined as maintenance of MRD negativity at 10-5 for ≥6 or ≥12 mo. Results: At the clinical cutoff date of January 11, 2018, 498 pts were included in the intent-to-treat (ITT) population (D-Vd, n = 251; Vd, n = 247). Pts received a median of 2 (1-10) PLs of therapy including 235 pts that received 1 PL (D-Vd, n = 122; Vd, n = 113). In the ITT population, 61% received prior ASCT, 66% V, 42% lenalidomide (R), and 32% were refractory to their last PL of therapy. Among 1 PL pts, 60% received prior ASCT, 51% V, 20% R, and 18% were refractory to their last PL of therapy. After a median follow-up of 31.3 mo, PFS was significantly prolonged with D-Vd compared with Vd in the ITT population (median: 16.7 vs 7.1 mo; HR, 0.32; 95% CI, 0.25-0.40, P

Description: INTRODUCTION. Bortezomib- and/or lenalidomide-based combinations are standard initial approaches in transplant (ASCT) ineligible NDMM. Different studies confirmed the advantages of continuous treatment. Despite the benefits of bortezomib maintenance, the parenteral administration and the risk of peripheral neuropathy (PN) limit its long-term use. The oral proteasome inhibitor (PI) Ixazomib plus Lenalidomide-dexamethasone was effective and well tolerated at diagnosis or relapse. The need for a convenient and well tolerated PI-based frontline therapy for an extended duration with minimal cumulative toxicity remains an unmet need for the elderly. In this prospective, multicenter, phase II randomized study, we assessed Ixazomib in combination with dexamethasone, Cyclophosphamide, Thalidomide or Bendamustine, followed by Ixazomib maintenance in ASCT-ineligible NDMM. METHODS. NDMM patients (pts) ≥65 years old or younger ASCT-ineligible could be enrolled. Treatment consisted of nine 28-day induction cycles of Ixazomib 4 mg on days 1,8,15 and dexamethasone 40 mg on days 1,8,15,22 (Id) or combined with Cyclophosphamide 300 mg/m2 orally on days 1,8,15 (ICd) or plus Thalidomide 100 mg/day (ITd) or plus Bendamustine 75 mg/m2 iv on days 1,8 (IBd); followed by maintenance with Ixazomib 4 mg on days 1,8,15 until progression. Because the study included the novel drug Ixazomib, dual stopping rules combining efficacy (at least very good partial response [VGPR] rate), and safety (predefined toxicity possibly related to Ixazomib) were planned and analyzed in a cohort of 5 patients in each arm during the first 4 cycles. Here we report the results of the cohort analysis during the first 4 cycles and the efficacy and safety analysis during induction treatment. RESULTS. In February 2017, the protocol was amended due to a low enrolment and the IBd arm, the only one including an iv drug, was closed. After closing this arm, all the other all oral arms continued the enrolment. Overall, 175 pts were enrolled (Id 42, ICd 61, ITd 61, and IBd 11 pts) and 171 pts started treatment. Median age was 74 years, 20% of pts had high risk cytogenetics, 44% were fit, 30% intermediate and 26% frail, according to the IMWG frailty score. Median follow-up was 13.2 months (IQR 8.9-20.7). During the first 4 cycles, at least VGPR rate was 24% with Id, 33% with ICd, 31% with ITd and 18% with IBd. In March 2018, after the analysis of the 4th cohort, the Id arm was closed due to high risk of inefficacy. Overall response rate (ORR) during induction was 73%, VGPR was 39%. ≥VGPR rates were 24% in Id, 48% in ICd, 43% in ITd and 27% in IBd. Median time to first response was 2.4 and to the best response 4 months. Responses were comparable according to cytogenetics: in high risk pts, ORR was 77%, ≥VGPR 46% and ≥nCR 17% as compared to 71%, 36% and 18% in standard risk pts (p=0.53, p=0.33 and p=1, respectively). Response rates were also comparable according to frailty status: in frail pts, ORR was 73%, ≥VGPR 36% and ≥nCR 11% as compared to 75%, 40% and 17% in intermediate and 70%, 40% and 22% in fit pts (p=0.78, p=0.90 and p=0.32, respectively). Median number of induction cycles was 9 (IQR 5-9); 93 (53%) pts completed induction treatment and 14 (8%) pts are still on induction treatment. During the first 4 cycles, hematologic toxicity was limited, and non-hematologic toxicity manageable. The most frequent G3-4 adverse event (AE) was rash in ITd arm (11%); discontinuation rate due to toxicity was 6%. During induction, the rate of at least 1 hematologic G≥3 AE was 11% and at least 1 non-hematologic G≥3 AE was 44%. The most frequent G≥3 AEs were neutropenia (8%), gastrointestinal (9%), infections (11%), neurologic (11%) and dermatologic (6%). G3-4 thrombocytopenia (3%) and PN (5%) were limited. Ixazomib dose reduction due to AEs was required in 15% of pts. The rate of non-hematologic AEs was slightly higher in ITd arm (37% in Id, 37% in ICd, 53% in ITd, 55% in IBd). Early death rate (

Description: Introduction: Diffuse Large B-Cell Lymphoma (DLBCL) is an heterogeneous disease: 30-40% of cases have high expression of MYC and BCL2 proteins (Dual Expressor, DE) and 5-10% have chromosomal rearrangements involving MYC, BCL2 and/or BCL6 (Double-/ Triple-Hit, DH/TH). Although the optimal treatment for those high-risk lymphomas remains undefined, DA-EPOCH-R produces durable remission with acceptable toxicity (Dunleauvy K, Lancet 2018). TP53 mutation is an independent marker of poor prognosis in patients (pts) with DLBCL treated with R-CHOP therapy. However, its prognostic value in poor prognosis lymphomas, receiving intensive therapy, has not been investigated yet. Methods: A series of consecutive pts (n=87) with biopsy proven diagnosis of DE DLBCL (MYC expression ≥40% and BCL2 expression ≥ 50% of tumor cells) or DE-Single Hit (DE-SH, i.e., DE-DLBCL with a single rearrangement of either MYC, BCL2 or BCL6 oncogenes) or DE-DH/TH (MYC, BCL2 and/or BCL6 rearrangements obtained by FISH) were treated with 6 cycles of DA-EPOCH-R and central nervous system (CNS) prophylaxis consisting of two courses of high-dose intravenous Methotrexate. Additional eligibility criteria included age ≥18 years and adequate organ functions. Cell of origin (COO) was defined according to Hans algorithm [germinal center B cell like (GCB) and non GCB)]. TP3 mutations were evaluated by next generation sequencing (NGS) based on AmpliseqTM technology or Sanger sequencing and considered positive when a variant allelic frequency ≥10% was detected. Results: Eighty-seven pts were included [n=36 DE only, n=32 DE-SH (n=8 MYC, n=10 BCL2, n=14 BCL6), n=19 DE-DH/TH] with 40 patients (46%) showing a non GCB COO. Pts had a median age of 59 years (range, 24-79 years). Seventy-three pts (84%) had advanced disease and 44 (50%) an high-intermediate/high-risk score as defined by International Prognostic Index (IPI). Only 8 of 87 pts (9%) were consolidated in first clinical remission with autologous stem cell transplantation following DA-EPOCH-R. After a median follow-up of 24 months, 73 are alive (84%) and 14 died [n=12 disease (n=2 CNS disease); n=1 pneumonia; n=1 suicide]. The 2-year PFS and OS were 71% (95%CI, 60-80%) and 76% (95%CI, 61%-85%) for the entire population. For those with IPI 3-5 the PFS and OS were not significant different for DE and DE-SH pts versus DE-DH/TH pts [64% vs 57% p=0.77); 78% vs 57% p=0.12)]. The COO did not influence the outcome for DE only and DE-SH [PFS: 78% vs 71% (p=0.71); 92% vs 86% (p=0.16) for GCB vs non -GCB, respectively]. Fourty-six pts (53%;n=18 DE only, n=18 DE-SH, n=10 DE-DH/TH ) were evaluated for TP53 mutations with 11 pts (24%) carrying a clonal mutation (n=6 in DE, n=3 in DE-SH, n=2 in DE-DH/TH). The 2-year PFS and OS did not significantly change for pts DE and DE-SH TP53 wild type as compared to DE and DE-SH mutated [PFS: 84 % vs 77%, (p=0.45); OS: 87% vs 88%, (p=0.92)]. The two pts DE-DH/TH with TP53 mutation are alive and in complete remission.Conclusions: High risk DLBCL pts treated with DA-EPOCH-R have a favourable outcome independently from high IPI score, DE-SH and DE-DH/TH. Also the presence of TP53 mutations does not negatively affect the outcome of pts treated with this intensive regimen. The efficacy of DA-EPOCH-R in overcoming poor prognostic genetic features in DLBCL should be confirmed in a larger prospective clinical trial. Disclosures Rossi: Daiichi-Sankyo: Consultancy; Roche: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Jazz: Membership on an entity's Board of Directors or advisory committees; Astellas: Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria; Mundipharma: Honoraria; BMS: Honoraria; Sandoz: Honoraria. Carlo-Stella:Takeda: Other: Travel, accommodations; F. Hoffmann-La Roche Ltd: Honoraria, Other: Travel, accommodations, Research Funding; Rhizen Pharmaceuticals: Research Funding; Celgene: Research Funding; Amgen: Honoraria; AstraZeneca: Honoraria; Janssen Oncology: Honoraria; MSD: Honoraria; BMS: Honoraria; Genenta Science srl: Consultancy; Janssen: Other: Travel, accommodations; Servier: Consultancy, Honoraria, Other: Travel, accommodations; Sanofi: Consultancy, Research Funding; ADC Therapeutics: Consultancy, Other: Travel, accommodations, Research Funding; Novartis: Consultancy, Research Funding; Boehringer Ingelheim: Consultancy. Corradini:AbbVie: Consultancy, Honoraria, Other: Travel Costs; KiowaKirin: Honoraria; Gilead: Honoraria, Other: Travel Costs; Amgen: Honoraria; Celgene: Honoraria, Other: Travel Costs; Daiichi Sankyo: Honoraria; Janssen: Honoraria, Other: Travel Costs; Jazz Pharmaceutics: Honoraria; Kite: Honoraria; Novartis: Honoraria, Other: Travel Costs; Roche: Honoraria; Sanofi: Honoraria; Takeda: Honoraria, Other: Travel Costs; Servier: Honoraria; BMS: Other: Travel Costs.

Description: Background: Tisagenlecleucel is an autologous anti-CD19 chimeric antigen receptor (CAR)-T cell therapy that is approved for adult patients (pts) with relapsed/refractory diffuse large B-cell lymphoma (r/r DLBCL). In the phase 2 JULIET trial, pts could receive bridging therapy (BT), when needed, to permit flexibility in scheduling and maintain disease control. Lymphodepleting chemotherapy (LDC) was started 5-14 days prior to CAR-T cell infusion. Here we present baseline characteristics, efficacy/safety outcomes, and cellular kinetics by BT and type of LDC used in the JULIET trial. Methods: Pts were categorized based on BT or no BT, as well as LDC (cyclophosphamide/fludarabine [Cy/Flu; 250 and 25 mg/m2 IV daily for 3 doses, respectively] or bendamustine [90 mg/m2 IV daily for 2 days]) or no LDC, received prior to tisagenlecleucel infusion. Cy/Flu was the proposed regimen for LDC, followed by bendamustine (if the pt experienced previous grade [G] 4 hemorrhagic cystitis with Cy or demonstrated resistance to a previous Cy-containing regimen). LDC was not required if white blood cell count was 8 weeks to ≤1 year post-infusion, 〉1 year post-infusion, and any time after infusion were generally consistent across BT and LDC groups for prolonged cytopenias, neurological events (NE), cytokine release syndrome (CRS), and infection (Table). Of note, among pts who did not receive BT, only 1 G3 CRS and 1 G3 NE were reported, and no G4 CRS or NE were reported. Additionally, the rate of cytopenias not resolved by day 28 post-infusion was lowest among pts who did not receive BT (1/11 pts). However, cytopenias resolved to ≤G2 by month 3 or month 6 in the majority of pts. Cmax, Tmax, and exposure (AUC0-28d) were similar between LDC groups (Table). Cmax and AUC0-28d were also similar between pts who received BT and those who did not. Additional analyses of subgroups will be presented at the congress. Conclusions: The majority of pts enrolled in the JULIET trial received BT and LDC, indicating high tumor burden and aggressive disease in this pt population with r/r DLBCL. Although the sample size is small (n=11), pts not requiring BT appeared to have less aggressive disease, achieved high response rates, and had no G4 CRS or NE. Pts who did not receive LDC (n=8) seemed to have low response rates, suggesting either the impact of prior therapy, the importance of LDC, or both. Further evaluation of the impact of BT and LDC on clinical outcomes on larger patient population will be possible with the availability of registry data. Clinical trial information: NCT02445248 Table Disclosures Andreadis: Genentech: Consultancy, Employment; Merck: Research Funding; Roche: Equity Ownership; Novartis: Research Funding; Celgene: Research Funding; Juno: Research Funding; Pharmacyclics: Research Funding; Gilead: Consultancy; Kite: Consultancy; Jazz Pharmaceuticals: Consultancy. Tam:BeiGene: Honoraria; Roche: Honoraria; Novartis: Honoraria; Janssen: Honoraria, Research Funding; Pharmacyclics LLC, an AbbVie company: Honoraria; AbbVie: Honoraria, Research Funding. Borchmann:Novartis: Honoraria, Research Funding. Jaeger:Novartis, Roche, Sandoz: Consultancy; AbbVie, Celgene, Gilead, Novartis, Roche, Takeda Millennium: Research Funding; Amgen, AbbVie, Celgene, Eisai, Gilead, Janssen, Novartis, Roche, Takeda Millennium, MSD, BMS, Sanofi: Honoraria; Celgene, Roche, Janssen, Gilead, Novartis, MSD, AbbVie, Sanofi: Membership on an entity's Board of Directors or advisory committees. McGuirk:Astellas: Research Funding; Novartis: Research Funding; Fresenius Biotech: Research Funding; Gamida Cell: Research Funding; Pluristem Ltd: Research Funding; ArticulateScience LLC: Other: Assistance with manuscript preparation; Juno Therapeutics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Kite Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Bellicum Pharmaceuticals: Research Funding. Holte:Novartis: Honoraria, Other: Advisory board. Waller:Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics: Other: Travel expenses, Research Funding; Cerus Corporation: Other: Stock, Patents & Royalties; Chimerix: Other: Stock; Cambium Oncology: Patents & Royalties: Patents, royalties or other intellectual property ; Amgen: Consultancy; Kalytera: Consultancy. Jaglowski:Unum Therapeutics Inc.: Research Funding; Novartis: Consultancy, Other: advisory board, Research Funding; Juno: Consultancy, Other: advisory board; Kite: Consultancy, Other: advisory board, Research Funding. Bishop:Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Juno: Consultancy, Membership on an entity's Board of Directors or advisory committees; CRISPR Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Kite: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Foley:Celgene: Speakers Bureau; Amgen: Speakers Bureau; Janssen: Speakers Bureau. Westin:Curis: Other: Advisory Board, Research Funding; Janssen: Other: Advisory Board, Research Funding; Juno: Other: Advisory Board; Celgene: Other: Advisory Board, Research Funding; 47 Inc: Research Funding; Genentech: Other: Advisory Board, Research Funding; Novartis: Other: Advisory Board, Research Funding; MorphoSys: Other: Advisory Board; Unum: Research Funding; Kite: Other: Advisory Board, Research Funding. Fleury:Gilead: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Roche: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; AstraZeneca: Consultancy. Ho:Novartis: Other: Trial Investigator meeting travel costs; La Jolla: Other: Trial Investigator meeting travel costs; Janssen: Other: Trial Investigator meeting travel costs; Celgene: Other: Trial Investigator meeting travel costs. Mielke:DGHO: Other: Travel support; IACH: Other: Travel support; EBMT/EHA: Other: Travel support; Miltenyi: Consultancy, Honoraria, Other: Travel and speakers fee (via institution), Speakers Bureau; GILEAD: Consultancy, Honoraria, Other: travel (via institution), Speakers Bureau; Jazz Pharma: Honoraria, Other: Travel support, Speakers Bureau; Kiadis Pharma: Consultancy, Honoraria, Other: Travel support (via institution), Speakers Bureau; Celgene: Honoraria, Other: Travel support (via institution), Speakers Bureau; ISCT: Other: Travel support; Bellicum: Consultancy, Honoraria, Other: Travel (via institution). Teshima:Novartis: Honoraria, Research Funding. Salles:Epizyme: Consultancy, Honoraria; Amgen: Honoraria, Other: Educational events; Autolus: Consultancy, Membership on an entity's Board of Directors or advisory committees; Roche, Janssen, Gilead, Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Educational events; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Educational events; BMS: Honoraria; Merck: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis, Servier, AbbVie, Karyopharm, Kite, MorphoSys: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Educational events. Schuster:Novartis: Patents & Royalties: Combination Therapies of CAR and PD-1 Inhibitors (royalties to Novartis); i3Health, Dava Oncology, Novartis, OncLive, PER Oncology: Speakers Bureau; AbbVie, Acerta, Celgene, DTRM Bio, Genentech, Incyte, Merck, Novartis, Portola, TG therapeutics: Research Funding; AbbVie, Celgene, Novartis, Nordic Nanovector, Pfizer: Other: steering committee; Acerta, AstraZeneca, Celgene, Juno, LoxoOncology, Novartis: Other: advisory board; i3Health, Acerta, AstraZeneca, Celgene, Dava Oncology, Juno, LoxoOncology, Novartis, Nordic Nanovector, OncLive, PER Oncology, Pfizer: Honoraria. Bachanova:Kite: Membership on an entity's Board of Directors or advisory committees; Novartis: Research Funding; Gamida Cell: Research Funding; GT Biopharma: Research Funding; Incyte: Research Funding; Celgene: Research Funding; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees. Maziarz:Novartis: Consultancy, Research Funding; Incyte: Consultancy, Honoraria; Celgene/Juno: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Kite: Membership on an entity's Board of Directors or advisory committees. Van Besien:Miltenyi Biotec: Research Funding. Izutsu:Eisai, Chugai, Zenyaku: Honoraria; Kyowa Kirin, Eisai, Takeda, MSD, Chugai, Nihon Medi-physics, Janssen, Ono, Abbvie, Dainihon Sumitomo, Bayer, Astra Zeneca, HUYA Japan, Novartis, Bristol-Byers Squibb, Mundi, Otsuka, Daiichi Sankyo, Astellas, Asahi Kasei: Honoraria; Celgene: Consultancy; Eisai, Symbio, Chugai, Zenyaku: Research Funding; Chugai, Celgene, Daiichi Sankyo, Astra Zeneca, Eisai, Symbio, Ono, Bayer, Solasia, Zenyaku, Incyte, Novartis, Sanofi, HUYA Bioscience, MSD, Astellas Amgen, Abbvie, ARIAD, Takeda, Pfizer: Research Funding. Wagner-Johnston:Gilead: Membership on an entity's Board of Directors or advisory committees; Jannsen: Membership on an entity's Board of Directors or advisory committees; Bayer: Membership on an entity's Board of Directors or advisory committees; ADC Therapeutics: Membership on an entity's Board of Directors or advisory committees. Corradini:Amgen: Honoraria; Celgene: Honoraria, Other: Travel Costs; AbbVie: Consultancy, Honoraria, Other: Travel Costs; Daiichi Sankyo: Honoraria; Gilead: Honoraria, Other: Travel Costs; Janssen: Honoraria, Other: Travel Costs; Jazz Pharmaceutics: Honoraria; KiowaKirin: Honoraria; Kite: Honoraria; Novartis: Honoraria, Other: Travel Costs; Roche: Honoraria; Sanofi: Honoraria; Servier: Honoraria; Takeda: Honoraria, Other: Travel Costs; BMS: Other: Travel Costs. Tiwari:Novartis: Employment. Awasthi:Novartis: Employment. Lawniczek:Novartis: Employment. Eldjerou:Novartis Pharmaceuticals Corporation: Employment. Kersten:MSD: Other: Travel grants, honorarium, or advisory boards; Janssen/Cilag: Other: Travel grants, honorarium, or advisory boards; Kite: Consultancy, Other: Travel grants, honorarium, or advisory boards; Roche: Consultancy, Research Funding, Travel grants, honorarium, or advisory boards; Bristol Myers Squibb: Other: Travel grants, honorarium, or advisory boards; Takeda: Consultancy, Research Funding; Novartis: Consultancy, Other: Travel grants, honorarium, or advisory boards; Celgene: Other: Travel grants, honorarium, or advisory boards; Gilead: Other: Travel grants, honorarium, or advisory boards; Amgen: Other: Travel grants, honorarium, or advisory boards; Roche: Other: Travel grants, honorarium, or advisory boards; Celgene: Consultancy, Research Funding.

Description: Background: In the phase 2 JULIET trial, tisagenlecleucel, an anti-CD19 CAR-T cell therapy, demonstrated durable responses and manageable safety in adult patients (pts) with r/r DLBCL. Here, we examine the impact of key product cellular attributes of tisagenlecleucel on clinical outcomes. Methods: JULIET is a single-arm, global, phase 2 trial of tisagenlecleucel in adult pts with r/r DLBCL. Samples from 115 tisagenlecleucel individual products were examined at the end of manufacturing at the batch release testing for various product attributes (Table). Additional detailed immunophenotyping for 66 attributes was conducted on previously frozen product samples via flow cytometry (FC). For each cell population of CAR+ T cells, the percentage and absolute number of the subpopulation were analyzed. Univariate and multivariate analyses were performed to evaluate effects of product attributes and CAR+ T-cell phenotypes on efficacy (Month 3 response [M3R], duration of response [DOR], progression-free survival [PFS], overall survival [OS]) and safety (cytokine release syndrome [CRS] and neurological events [NE], grade 0-2 [low] vs 3-4 [severe]). Several exploratory approaches, including machine learning methods (eg, elastic net and random forest), were pursued in conjunction with logistic regression to identify a set of variables associated with clinical outcomes. We included clinically relevant characteristics evaluated at baseline per protocol (LDH, CRP, and tumor volume) with the product attributes in multivariate modeling. Logistic regression was used to model M3R, CRS, and NE. Cox regression was used to model DOR, PFS, and OS. Results: As of December 11, 2018, 115 pts were infused and evaluable. The median T-cell transduction efficiency by FC was 28% (range, 5.3-63.2%); no relationship of these attributes with efficacy (M3R, DOR, PFS, or OS) or safety (severe CRS or NE) was observed. The percentage of viable cells had no impact on efficacy or safety outcomes; this was anticipated since tisagenlecleucel dose is formulated based on the number of viable CAR+ T cells. Tisagenlecleucel demonstrated in vitro functional activity upon CD19-specific stimulation, as evidenced by IFNγ release, with a wide range among different batches (range, 23.7-938 fg/CAR+ cell). Durable responses were observed across the entire range of IFNγ release; high IFNγ release was not associated with severe CRS or NE. The median ratio of CAR+ CD4+ to CD8+ cells was 3.70 (range, 0.26-65.3); no relationship with clinical outcomes was observed (Figure). CAR+ T cells showed variability in T-cell phenotypes, with central memory (CM) cells as the predominant subpopulation of both CD4+ and CD8+ CAR+ T cells (Figure). The majority of CAR+ T cells were highly activated (co-expressing HLA-DR and CD38), as measured by FC. Relative and absolute number of less mature T cells (naive and CM T cells) in the product did not correlate with efficacy. There was no significant correlation between cell populations and efficacy on multivariate analyses. For CRS, the total number of certain CD4+ T cells expressing activation markers (HLA-DR+, CD25+, or HLA-DR+CD38+) and CM cells showed trends of correlation with more severe CRS, but none of these were significant after p-value adjustment; in a multivariate regression model adjusted for LDH and other clinically relevant factors, HLA-DR+ CD38+CD4+ T cells showed a correlation with severe CRS. Correlation analyses did not reveal product attributes significantly related to severe NE. Conclusions: In JULIET, tisagenlecleucel CAR-T cell product attributes had no significant impact on efficacy or NE; the total number of activated CD4+ cells infused positively correlated with higher-grade CRS. There is great variability in the product attributes, especially with respect to T-cell phenotypes, though this variability appears to play a minor role on efficacy. Additional analyses with larger data sets are required to confirm these findings. ClinicalTrials.gov Identifier: NCT02445248. Disclosures Bachanova: Novartis: Research Funding; Gamida Cell: Research Funding; GT Biopharma: Research Funding; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees; Kite: Membership on an entity's Board of Directors or advisory committees; Celgene: Research Funding; Incyte: Research Funding. Tam:BeiGene: Honoraria; Janssen: Honoraria, Research Funding; Roche: Honoraria; Novartis: Honoraria; AbbVie: Honoraria, Research Funding. Jaeger:Novartis, Roche, Sandoz: Consultancy; AbbVie, Celgene, Gilead, Novartis, Roche, Takeda Millennium: Research Funding; Amgen, AbbVie, Celgene, Eisai, Gilead, Janssen, Novartis, Roche, Takeda Millennium, MSD, BMS, Sanofi: Honoraria; Celgene, Roche, Janssen, Gilead, Novartis, MSD, AbbVie, Sanofi: Membership on an entity's Board of Directors or advisory committees. McGuirk:Novartis: Research Funding; Fresenius Biotech: Research Funding; Astellas: Research Funding; Bellicum Pharmaceuticals: Research Funding; Kite Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Gamida Cell: Research Funding; Pluristem Ltd: Research Funding; ArticulateScience LLC: Other: Assistance with manuscript preparation; Juno Therapeutics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Holte:Novartis: Honoraria, Other: Advisory board. Waller:Amgen: Consultancy; Kalytera: Consultancy; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics: Other: Travel expenses, Research Funding; Cerus Corporation: Other: Stock, Patents & Royalties; Chimerix: Other: Stock; Cambium Oncology: Patents & Royalties: Patents, royalties or other intellectual property . Jaglowski:Juno: Consultancy, Other: advisory board; Kite: Consultancy, Other: advisory board, Research Funding; Novartis: Consultancy, Other: advisory board, Research Funding; Unum Therapeutics Inc.: Research Funding. Bishop:CRISPR Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees; Kite: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Juno: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Andreadis:Celgene: Research Funding; Novartis: Research Funding; Jazz Pharmaceuticals: Consultancy; Roche: Equity Ownership; Pharmacyclics: Research Funding; Merck: Research Funding; Gilead: Consultancy; Kite: Consultancy; Genentech: Consultancy, Employment; Juno: Research Funding. Foley:Celgene: Speakers Bureau; Amgen: Speakers Bureau; Janssen: Speakers Bureau. Westin:Unum: Research Funding; Genentech: Other: Advisory Board, Research Funding; Novartis: Other: Advisory Board, Research Funding; Janssen: Other: Advisory Board, Research Funding; Juno: Other: Advisory Board; Kite: Other: Advisory Board, Research Funding; 47 Inc: Research Funding; Curis: Other: Advisory Board, Research Funding; MorphoSys: Other: Advisory Board; Celgene: Other: Advisory Board, Research Funding. Fleury:Gilead: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Roche: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; AstraZeneca: Consultancy. Ho:Janssen: Other: Trial Investigator meeting travel costs; Celgene: Other: Trial Investigator meeting travel costs; La Jolla: Other: Trial Investigator meeting travel costs; Novartis: Other: Trial Investigator meeting travel costs. Mielke:Miltenyi: Consultancy, Honoraria, Other: Travel and speakers fee (via institution), Speakers Bureau; DGHO: Other: Travel support; Jazz Pharma: Honoraria, Other: Travel support, Speakers Bureau; EBMT/EHA: Other: Travel support; Celgene: Honoraria, Other: Travel support (via institution), Speakers Bureau; ISCT: Other: Travel support; Bellicum: Consultancy, Honoraria, Other: Travel (via institution); GILEAD: Consultancy, Honoraria, Other: travel (via institution), Speakers Bureau; Kiadis Pharma: Consultancy, Honoraria, Other: Travel support (via institution), Speakers Bureau; IACH: Other: Travel support. Teshima:Novartis: Honoraria, Research Funding. Salles:Roche, Janssen, Gilead, Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Educational events; Amgen: Honoraria, Other: Educational events; BMS: Honoraria; Merck: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis, Servier, AbbVie, Karyopharm, Kite, MorphoSys: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Educational events; Autolus: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Educational events; Epizyme: Consultancy, Honoraria. Schuster:Celgene: Consultancy, Honoraria, Research Funding; Acerta: Consultancy, Honoraria, Research Funding; Loxo Oncology: Consultancy, Honoraria; AstraZeneca: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria; Pharmacyclics: Consultancy, Honoraria, Research Funding; Merck: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Research Funding; Nordic Nanovector: Consultancy, Honoraria; Genentech: Consultancy, Honoraria, Research Funding; Novartis: Honoraria, Patents & Royalties: Combination CAR-T and PD-1 Inhibitors, Research Funding; Gilead: Consultancy, Honoraria, Research Funding. Maziarz:Kite: Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Research Funding; Incyte: Consultancy, Honoraria; Celgene/Juno: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Van Besien:Miltenyi Biotec: Research Funding. Izutsu:Eisai, Chugai, Zenyaku: Honoraria; Chugai, Celgene, Daiichi Sankyo, Astra Zeneca, Eisai, Symbio, Ono, Bayer, Solasia, Zenyaku, Incyte, Novartis, Sanofi, HUYA Bioscience, MSD, Astellas Amgen, Abbvie, ARIAD, Takeda, Pfizer: Research Funding; Eisai, Symbio, Chugai, Zenyaku: Research Funding; Kyowa Kirin, Eisai, Takeda, MSD, Chugai, Nihon Medi-physics, Janssen, Ono, Abbvie, Dainihon Sumitomo, Bayer, Astra Zeneca, HUYA Japan, Novartis, Bristol-Byers Squibb, Mundi, Otsuka, Daiichi Sankyo, Astellas, Asahi Kasei: Honoraria; Celgene: Consultancy. Kersten:Celgene: Consultancy, Research Funding; Kite: Consultancy, Other: Travel grants, honorarium, or advisory boards; Janssen/Cilag: Other: Travel grants, honorarium, or advisory boards; Takeda: Consultancy, Research Funding; Novartis: Consultancy, Other: Travel grants, honorarium, or advisory boards; Gilead: Other: Travel grants, honorarium, or advisory boards; Amgen: Other: Travel grants, honorarium, or advisory boards; Roche: Other: Travel grants, honorarium, or advisory boards; Celgene: Other: Travel grants, honorarium, or advisory boards; Roche: Consultancy, Research Funding, Travel grants, honorarium, or advisory boards; MSD: Other: Travel grants, honorarium, or advisory boards; Bristol Myers Squibb: Other: Travel grants, honorarium, or advisory boards. Wagner-Johnston:ADC Therapeutics: Membership on an entity's Board of Directors or advisory committees; Bayer: Membership on an entity's Board of Directors or advisory committees; Jannsen: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees. Corradini:Celgene: Honoraria, Other: Travel Costs; Jazz Pharmaceutics: Honoraria; KiowaKirin: Honoraria; Kite: Honoraria; Novartis: Honoraria, Other: Travel Costs; Roche: Honoraria; Sanofi: Honoraria; Servier: Honoraria; Takeda: Honoraria, Other: Travel Costs; BMS: Other: Travel Costs; AbbVie: Consultancy, Honoraria, Other: Travel Costs; Amgen: Honoraria; Janssen: Honoraria, Other: Travel Costs; Gilead: Honoraria, Other: Travel Costs; Daiichi Sankyo: Honoraria. Chu:Novartis: Employment. Gershgorin:Novartis: Employment. Choquette:Novartis: Employment. Bubuteishvili Pacaud:Novartis: Employment. Jeschke:Novartis: Employment.

Description: Introduction: Allogeneic hematopoietic stem cell transplantation (alloHSCT) is currently considered the standard of care for those patients with HL that relapse after autologous HSCT. Several studies have shown that fit patients with chemosensitive disease can benefit from alloHSCT using and identical sibling (SIB) or matched-unrelated (MUD) donors. Recently, encouraging results have been obtained using haploidentical donors (HAPLO) and post-transplantation cyclophosphamide (ptCY) as graft-versus-host disease prophylaxis (GVHD). Because information regarding the results of alloHSCT using alternative donors is still scarce, we aimed to compare outcome of umbilical cord blood (UCB) and HAPLO transplants with conventional SIB and MUD for HL. Patients and methods: Information of patients older than 17y with HL who received an alloHSCT from a SIB, MUD (8/8 antigen matched), UCB or a ptCY-based HAPLO between 2010-2013 was downloaded from the EBMT and GETH databases. Results: 773 patients with HL were identified meeting the inclusion criteria. 339 received a transplant from a SIB donor, 276 from a MUD, 101 from HAPLO, and 47 from UCB. A significant higher number of patients treated with alloHSCT from UCB and HAPLO donors received reduced intensity (RIC) regimens in comparison to SIB and MUD (76% and 88% vs. 69% and 69%, respectively, p=0.001). Bone marrow was more frequently used as source of stem cells in the HAPLO group in relation to SIB and MUD (61% vs 10% and 11%, respectively, p=0.001), Other variables such as sex, age, performance status, chemorefractory disease, and previous autologous SCT were balanced. Median follow-up after alloHSCT for all patients was 12 months (1-60). The 1-year probabilities of overall survival (OS) and progression-free survival (PFS) were 80% and 49% after SIB transplant, 69% and 54% after MUD, 65% and 40% after UCB, and 73% and 56% after HAPLO, respectively. The 1-year probabilities of non-relapse mortality (NRM) and relapse rate (RR) were 12% and 38% after SIB, 21% and 25% after MUD, 20% and 40% after UCB, and 18% and 27% after HAPLO. Multivariate analysis showed that, in comparison with standard SIB alloHSCT, UCB was associated with a trend to a higher NRM (p=0.08) and RR (p=0.06), leading to a significant lower OS and PFS (p=0.009, HR 2.1, 95% CI 1.2-3.6; p=0.02, HR 1.6, 95% CI 1.1-2.3; respectively). NRM was also significantly higher after MUD (p=0.004, HR 1.8, 95% CI 1.2-2.6), but in contrast, RR was lower (p=0.003 HR 0.6, 95%CI 0.5-0.9) with a lower OS (p=0.002, HR 1.6, 95% CI 1.2-2.1) and no significant differences in PFS. No significant differences were observed between HAPLO and SIB in NRM, RR, PFS and OS. Conclusions: This registry study suggests that in adults with advanced HL, the outcome of pt-CY-based HAPLO HSCT may be comparable to that of conventional SIB alloHSCT and MUD across multiple centers and conditioning regimens. These findings need to be corroborated by longer follow-up. Figure 1. Figure 1. Disclosures Peggs: Autolus: Consultancy, Equity Ownership; Cellectis: Research Funding. Milpied:Celgene: Honoraria, Research Funding. Afanasiev:CELLTRION, Inc.: Research Funding. Russell:Therakos: Other: shares. Sureda:Takeda: Consultancy, Honoraria, Speakers Bureau.

Description: Introduction: For pts with RRMM who have failed or progressed on treatment (Tx) with newer agents, such as lenalidomide (LEN) and bortezomib (BORT), there are few Tx options, and overall survival (OS) is short (Kumar et al, Leukemia, 2012). POM is a distinct immunomodulatory agent with tumoricidal and immunoregulatory effects, and POM + LoDEX is approved in the United States and European Union for the Tx of pts with RRMM who have had ≥ 2 prior Tx, including LEN and BORT. Tx with POM + LoDEX has shown statistically greater survival benefits than high-dose DEX (MM-003; San Miguel et al, Lancet Oncol, 2013) or POM alone (MM-002; Richardson et al, Blood, 2014). POM + LoDEX has also demonstrated high overall response rates in pts with RRMM in the STRATUS trial (MM-010), a single-arm, open-label phase 3b study being conducted in 19 countries across Europe with a primary endpoint of safety (Dimopoulos et al, EHA 2015). Italian pts constituted the largest national subset in MM-010; hence, this subanalysis examines the safety and efficacy of POM + LoDEX in pts from Italy. Patients and Methods: Pts with RRMM (progressive disease [PD] on or within 60 days of last prior Tx) who had experienced Tx failure with BORT and LEN and had received adequate prior alkylator therapy were eligible. Pts received POM 4 mg on days 1-21 of a 28-day cycle in combination with DEX 40 mg (20 mg for pts aged 〉 75 yrs) on days 1, 8, 15, and 22. Thromboprophylaxis was required for all pts, and Tx was continued until PD or unacceptable toxicity. Results: A total of 219 pts were enrolled in MM-010 in Italy. The median age of this patient population was 67.0 yrs (range, 42-84 yrs), and 54.8% of pts were male. The median time since diagnosis was 5.5 yrs, and 37.0% of pts were International Staging System stage III. Patients were heavily pretreated, with a median of 4 prior anti-myeloma regimens (range, 2-11), and most pts were refractory to LEN (95%), BORT (82.2%), or both LEN and BORT (78.1%). As of May 4, 2015, 2 pts (0.9%) were not treated, 54 pts (24.7%) were still on treatment, and 163 pts (74.4%) had discontinued. After a median follow-up of 11.3 mos, in the intention-to-treat population, the overall response rate was 37.9% (range, 31.4%-44.7%), the median duration of response was 6.8 mos (95% CI, 4.9-10.8 mos), progression-free survival (PFS) was 5.2 mos (95% CI, 4.4-6.4 mos), and OS was 12.0 mos (95% CI, 10.6-15.2 mos). The most frequent grade 3/4 treatment-emergent AEs were neutropenia (56.7%), anemia (25.8%), thrombocytopenia (23.5%), and pneumonia (12.4%). Incidence of grade 3/4 venous thromboembolism (deep vein thrombosis and pulmonary embolism) and peripheral neuropathy were infrequent (2.3% and 0%, respectively). The most common reasons for discontinuation were disease progression (49.8%), death (10.0%), and adverse events (AEs; 5.0%). AEs led to dose reductions or interruptions of POM in 23.0% and 71.0% of pts, respectively, and the median relative dose intensity for POM was 0.90. Conclusions: In line with previous studies, POM + LoDEX was active in Italian pts, a representative subset of the heavily pretreated MM-010 population. PFS and OS were consistent with those seen in previous trials. POM + LoDEX treatment was well tolerated, and discontinuations due to AEs were infrequent, consistent with the well-known toxicity profile and the appropriate drug management. This study confirms that POM + LoDEX is effective in patients with advanced RRMM, including those who have experienced failure of prior Tx with BORT and/or LEN. Disclosures Cavo: Janssen-Cilag, Celgene, Amgen, BMS: Honoraria. Petrini:Novartis: Research Funding; Celgene Corporation: Research Funding; Italfarmaco: Research Funding; Roche: Research Funding. Caravita di Toritto:Celgene Corporation: Honoraria, Research Funding. Offidani:Celgene, Janssen: Honoraria. Petrucci:Celgene Corporation: Honoraria; Janssen-Cilag: Honoraria; Amgen: Honoraria; Mundipharma: Honoraria; BMS: Honoraria. Rodeghiero:Celgene Corporation: Honoraria, Research Funding. Simcock:Celgene Corporation: Employment. Slaughter:Celgene Corporation: Employment, Equity Ownership. Herring:Celgene Corporation: Employment. Peluso:Celgene Corporation: Employment. Palumbo:Celgene, Millennium Pharmaceuticals, Amgen, Bristol-Myers Squibb, Genmab, Janssen-Cilag, Onyx Pharmaceuticals: Consultancy, Honoraria; Novartis, Sanofi Aventis: Honoraria.

Description: Background: The introduction of newer agents, such as lenalidomide (LEN) and bortezomib (BORT), has improved survival outcomes for pts with RRMM (Kumar et al Leukemia, 2014). However, overall survival (OS) in pts who have failed or progressed on treatment (Tx) with newer agents is short and there are few additional treatment options available (Kumar et al Leukemia, 2012). POM is a distinct immunomodulatory agent with tumoricidal and immunoregulatory effects approved in combination with DEX for the Tx of pts with RRMM in the US and EU with ≥ 2 prior Txs, including LEN and BORT. Pivotal trials with POM + LoDEX have demonstrated greater survival benefits when compared with high-dose DEX (MM-003; San Miguel et al Lancet Oncol, 2013) or POM alone (MM-002; Richardson et al Blood, 2014). The STRATUS trial (MM-010; ClinicalTrials.gov: NCT01712789; EudraCT: 2012-001888-78) is a single-arm, open-label, phase 3b study being conducted in 19 countries across Europe designed to further evaluate safety and efficacy of POM + LoDEX in RRMM. Here, we present an updated analysis of safety and efficacy. Methods: Pts with refractory or relapsed and refractory disease (progressive disease [PD] on or within 60 days of last prior Tx), Tx failure with BORT and LEN, and adequate prior alkylator therapy were eligible. Pts with the following laboratory values were excluded: absolute neutrophil count 〈 800/μL; platelets 〈 75,000 or 〈 30,000/μL for pts with 〈 50% or ≥ 50% of bone marrow nucleated cells as plasma cells, respectively; creatinine clearance 〈 45 mL/min; hemoglobin 〈 8 g/dL; and peripheral neuropathy (PN) grade (Gr) ≥ 2. POM 4 mg was administered days 1-21 of a 28-day cycle in combination with LoDEX 40 mg/day (20 mg for pts aged 〉 75 yrs) on days 1, 8, 15, and 22 until PD or unacceptable toxicity. Thromboprophylaxis was required for all pts.Follow up continued for subsequent Tx, OS, and second primary malignancy until 5 yrs post enrollment. Safety was the primary end point, and key secondary end points included overall response rate (ORR) (≥ partial response), duration of response (DOR), progression-free survival (PFS), OS, and POM exposure. Results: A total of 682 pts were enrolled. The median age was 66 yrs (range, 37-88 yrs), and the median time since diagnosis was 5.3 yrs (range, 0.5-28.1 yrs). Pts were heavily pretreated with a median of 5 prior regimens (range, 2-18). Most pts were refractory to LEN (96%), BORT (84%), or LEN and BORT (80%). As of May 4, 2015, the median follow up was 16.8 mos and the median duration of Tx was 4.9 mos. In the 676 pts receiving POM + LoDEX, the most frequent Gr 3/4 treatment-emergent adverse events (TEAEs) were hematologic events (neutropenia [49.7%], anemia [33.0%], and thrombocytopenia [24.1%]. The most common Gr 3/4 nonhematologic toxicities were pneumonia (12.9%), fatigue (5.9%), and hypercalcemia (5.0%). Incidences of Gr 3/4 venous thromboembolism (deep vein thrombosis and pulmonary embolism) and PN were low (1.6% and 1.5%, respectively). Dose reductions, interruptions, and discontinuations of POM due to TEAEs were required in 22.0%, 66.3%, and 6.1% of pts; respectively. The ORR was 32.6%, with 0.6%, 7.6%, and 24.3% of pts achieving a complete response, very good partial response, and partial response, respectively. The median DOR was 7.4 mos. Median PFS and OS were 4.6 mos and 11.9 mos, respectively (Figure). Conclusions: The updated safety and efficacy results of STRATUS, the largest study of POM + LoDEX in a heavily pretreated RRMM population, were in line with results from the pivotal trials demonstrating that POM + LoDEX is effective and well tolerated. This analysis confirms that POM + LoDEX is a standard of care for pts with RRMM. Disclosures Dimopoulos: Janssen: Honoraria; Janssen-Cilag: Honoraria; Genesis: Honoraria; Celgene: Honoraria; Novartis: Honoraria; Onyx: Honoraria; Amgen: Honoraria. Palumbo:Celgene, Millennium Pharmaceuticals, Amgen, Bristol-Myers Squibb, Genmab, Janssen-Cilag, Onyx Pharmaceuticals: Consultancy, Honoraria; Novartis, Sanofi Aventis: Honoraria. Cavo:Janssen-Cilag, Celgene, Amgen, BMS: Honoraria. Delforge:Novartis: Honoraria; Celgene Corporation: Honoraria; Janssen: Honoraria; Amgen: Honoraria. Weisel:Amgen: Consultancy, Honoraria, Other: Travel Support; Janssen Pharmaceuticals: Consultancy, Honoraria, Other: Travel Support, Research Funding; Celgene: Consultancy, Honoraria, Other: Travel Support, Research Funding; Novartis: Other: Travel Support; BMS: Consultancy, Honoraria, Other: Travel Support; Onyx: Consultancy, Honoraria; Noxxon: Consultancy. Di Raimondo:Celgene Corporation: Research Funding, Speakers Bureau. Simcock:Celgene Corporation: Employment. Miller:Celgene Corporation: Employment, Equity Ownership. Slaughter:Celgene Corporation: Employment, Equity Ownership. Peluso:Celgene Corporation: Employment. Sternas:Celgene Corporation: Employment, Equity Ownership. Zaki:Celgene Corporation: Employment, Equity Ownership. Moreau:Celgene: Honoraria, Other: Adboard; Amgen: Other: Adboard; Janssen: Honoraria, Other: Adboard; Takeda: Honoraria, Other: Adboard; Novartis: Honoraria, Other: Adboard.

Description: Background: The achievement of complete remission is an important therapeutic goal and prognostic factor for overall survival in patients with B-cell malignancies. Molecular monitoring of disease with PCR-based strategies is used to assess the depth of treatment response, detect minimal residual disease (MRD), and identify patients at increased risk of relapse. Immunoglobulin heavy chain (IGH) gene rearrangements are used as molecular marker in approximately 80% of lymphoma and multiple myeloma (MM) patients since they represent lineage-specific markers and the third complementarity determining region (CDR3) is unique to each clone. We and others have demonstrated that next generation sequencing (NGS) technologies provide the opportunity to identify and quantify clonotypes with consensus primers combining the benefits of high sensitivity and universal applicability thus overcoming ASO-PCR and RQ-PCR limitations. Very recently, NGS has been applied to characterize the tumor-specific VDJ recombination of the immunoglobulin genes in the serum of patients with diffuse large B-cell lymphoma and used as a novel non-invasive strategy to predict clinical disease recurrence after first-line treatment (Roschewski et al., Lancet Oncology 2015). The present study was designed to assess whether the Ion Torrent Personal Genome Machine (IT-PGM)-based sequencing and analysis we established (Gimondi et al., ASH 2014), could be used to detect circulating tumor DNA encoding the clonal immunoglobulin gene sequence in the plasma of patients with Multiple Myeloma. Methods: Genomic DNA (gDNA) was extracted from CD138+ plasma cells immunomagnetically selected from the bone marrow blood of six MM patients and amplified using seven different family-specific IgH-V primers and a consensus JH primer (Voena et al., Leukemia 1997). IgH clonality was assessed by Sanger sequencing in order to define the patient specific DNA rearrangement. Plasma samples of the six MM patients were collected and cell free DNA (cfDNA) extracted (Qiagen). The total amount of cfDNA was estimated by fluorometric measurement (median 105 ng, range 37-171 ng).For library construction and NGS, paired samples of gDNA (500ng) and cfDNA (at least 37ng) were amplified as previously described (Gimondi et al., ASH 2014). PCR products were evaluated for quality and length by high-sensitivity dsDNA chips (Agilent).PCR amplicons were barcoded, pooled and sequenced on the Ion Torrent PGM.NGS data were analyzed by using the IMGT-High V-Quest web server tool and the statistical software R. Results: Rearranged IGHV-D-J loci from cfDNA of each MM patient could be amplified using 7 different IGHV family primers and a consensus JH primer, despite the limited abundance of DNA recovered from plasma samples. PCR products were sequenced on an IT-PGM 316 chip, yielding at least 110K reads per sample (mean 280K reads) with an average coverage of 130x (at least 50x). Clonal IgH sequences were quantified as a fraction of the complete IGHV-D-J rearranged reads. The clonality of our samples was assessed by determining the percentage of reads identical to the most abundant CDR3 sequence in each sample. The number of clonal sequences corresponding to the highest expressed IGH clonotype in gDNA was consistent with those identified in cfDNA samples (range 74%-82% and range 65%-73% respectively). Furthermore, the clonotypes identified by high-throughput sequencing of gDNA and cfDNA samples demonstrated a 100% sequence identity with the patient-specific IGHV-D-J clonal rearrangement identified by Sanger sequencing. Conclusions: We demonstrate that next generation sequencing of cfDNA from the plasma of Multiple Myeloma patients is feasible, accurate, and sensitive in identifying the tumor-derived VDJ recombination of the immunoglobulin genes without prior knowledge of the tumor clonotype and might represent an alternative when bone marrow biopsies are unavailable. Moreover, given the patchy bone infiltration of malignant plasma cells, cfDNA analysis is a non-invasive approach that might give a more precise quantification of disease burden. In addition, NGS analysis of the IGHV-D-J rearranged sequences provides a deep and detailed characterization of the patient immune repertoire, thus possibly allowing clonal evolution evaluations and monitoring of MRD in follow-up samples. Disclosures No relevant conflicts of interest to declare.