Abstract: Introduction: Multiple myeloma (MM) evolves from precursor disorders such as monoclonal gammopathy of undetermined significance (MGUS) and SMM (Landgren O, et al. Blood 2009. 113[22]:5412-5417). Currently, there are no approved therapies for SMM, and guidelines recommend close monitoring of SMM patients (pts) and initiating treatment only upon progression to MM. However, therapeutic intervention at the SMM stage, especially in pts at higher risk of progression to MM, may yield clinical benefit and prevent the development of MM-associated complications. DARA is a CD38-targeting IgG1κ monoclonal antibody with on-tumor and immunomodulatory mechanisms of action. Based on the demonstrated efficacy and favorable safety profile of DARA monotherapy in pts with relapsed/refractory MM (RRMM; Usmani SZ, et al. Blood 2016. 128[1] :37-44), we hypothesized that DARA could delay progression from SMM to MM. A prespecified primary analysis (15.8-month median follow-up) of the phase 2 CENTAURUS study (NCT02316106) revealed that DARA monotherapy was active and well tolerated in pts with intermediate- or high-risk SMM (Hofmeister CC, et al. ASH 2017. Abstract 510). Here, we present updated data from CENTAURUS based on 10 months of additional follow-up. Methods: Eligible pts had had a confirmed diagnosis of high-risk or intermediate-risk SMM for 〈 5 years. Pts were randomized (1:1:1) to receive 8-week cycles of DARA 16 mg/kg intravenously on 1 of 3 treatment schedules. Pts on the Long dosing schedule received DARA QW (Cycle 1), Q2W (Cycles 2-3), Q4W (Cycles 4-7), and Q8W (Cycles 8-20). On the Intermediate dosing schedule (Int), pts received DARA QW (Cycle 1) and Q8W (Cycles 2-20). Pts on the Short dosing schedule received 1 cycle of DARA QW. Rate of complete response (CR) or better and progressive disease (PD)/death rate (defined as the ratio of pts with an event [PD or death] to the total follow-up for all pts) were co-primary endpoints. CR and PD were defined per 2014 International Myeloma Working Group criteria (Rajkumar et al. Lancet Oncol 2014;15[12] :e538-e548). Biochemical progression and biochemical/diagnostic (BOD) progression were defined as previously reported (Hofmeister CC, et al. ASH 2017. Abstract 510). Results: A total of 123 pts were randomized (41 pts per arm). The median (range) age was 61.0 (31-81) years, and the median (range) time from initial SMM diagnosis to randomization was 6.83 (0.40-56.0) months. In total, 73% of pts were of IgG subtype. Median treatment duration was 25.8 months in both the Long and Int arms and 1.6 months in the Short arm (Table 1). In the Long, Int, and Short arms, 17%, 22%, and 5% of pts, respectively, discontinued treatment; reasons included PD (7%, 10%, and 0%, respectively), adverse events (AEs; 7%, 2%, and 5%, respectively), refusal of further treatment (5% in Int), withdrawal of consent (2% each in Long and Int), and death (2% in Int). At a median (range) follow-up of 25.9 (0-33.2) months, overall response and ≥CR rates were higher in the Long and Int arms than in the Short arm (Table 2); in the combined Long and Int arms, the ≥CR rate was 7%. Median PFS based on SLiM-CRAB criteria was not reached in any arm; 24-month PFS rates were 90% (Long), 82% (Int), and 75% (Short; Figure 1A). PD/death rates indicate a median PFS of ≥24 months in all arms (Table 2). Median PFS based on BOD criteria was reached in the short arm only (14.8 months); 24-month PFS rates were 78% (Long), 70% (Int), and 27% (Short; Figure 1B). Safety results are summarized in Table 1. In all arms, no hematologic treatment-emergent AE was observed in ≥10% of pts, and the rates of grade 3/4 infections were ≤5%. Deaths occurred in 1 pt (2%) in the Int arm (due to heart failure not related to DARA) and 1 pt (2%) in the Short arm (due to PD); no deaths were observed in the Long arm. No deaths occurred within 30 days of the last DARA dose. Conclusions: After median follow-up of 25.9 months, a more pronounced BOD PFS benefit was observed in the Long and Int arms compared with the Short arm. The safety profile of DARA monotherapy in SMM remains consistent with other single-agent DARA studies, and no new safety signals were observed with longer follow-up. Because dose intensity was associated with efficacy in SMM pts, an extended, dose-intensive schedule was selected for an ongoing phase 3 study of DARA monotherapy versus active monitoring in SMM (AQUILA). Disclosures Landgren: Celgene: Consultancy, Research Funding; Karyopharm: Consultancy; Pfizer: Consultancy; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Merck: Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Consultancy, Research Funding. Cavo:AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Adaptive Biotechnologies: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; GlaxoSmithKline: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Chari:Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Adaptive Biotechnology: 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; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol Myers Squibb: Consultancy; Pharmacyclics: Research Funding; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Array Biopharma: Research Funding; The Binding Site: Consultancy. Cohen:Janssen: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Takeda: Honoraria, Research Funding. Spencer:Celgene: Honoraria, Research Funding, Speakers Bureau; Janssen-Cilag: Honoraria, Research Funding, Speakers Bureau; Amgen: Honoraria, Research Funding; BMS: Research Funding; Takeda: Honoraria, Research Funding, Speakers Bureau; STA: Honoraria. Voorhees:Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: served on an IRC; BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Oncopeptides: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: served on an IRC; Novartis: Consultancy, Other: served on an IRC; TeneoBio: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen Inc.: Speakers Bureau. Estell:Janssen: Membership on an entity's Board of Directors or advisory committees. Sandhu:Bioverativ: Honoraria; Celgene: Honoraria; Amgen: Honoraria; Novartis: Honoraria; Janssen: Honoraria. Jenner:Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Williams:Takeda: Honoraria, Other: travel support, Speakers Bureau; Celgene: Honoraria, Other: travel support, Speakers Bureau; Amgen: Honoraria, Speakers Bureau; Janssen: Honoraria, Other: travel support, Speakers Bureau; Novartis: Honoraria. van de Donk:Janssen Pharmceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Amgen: Research Funding; Novartis: Research Funding; Bristol-Myers Squibb: Research Funding; Celgene: Research Funding. Beksac:Amgen,Janssen-Cilag,Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Membership on an entity's Board of Directors or advisory committees. Goldschmidt:Chugai: Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Mundipharma: Research Funding; Amgen: Consultancy, Research Funding; Sanofi: Consultancy, Research Funding; Takeda: Consultancy, Research Funding; Novartis: Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Bristol Myers Squibb: Consultancy, Honoraria, Research Funding; Adaptive Biotechnology: Consultancy; ArtTempi: Honoraria. Moreau:Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees. Kuppens:Janssen Research & Development: Employment. Bandekar:Janssen Research & Development: Employment. Neff:Janssen Research & Development: Employment. Cortoos:Janssen Research & Development: Employment. Clemens:Janssen Research & Development, LLC: Employment. Qi:Janssen: Employment. Adams:Janssen Pharmaceutical R & D: Employment. Hofmeister:Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Research Funding; Adaptive biotechnologies: Membership on an entity's Board of Directors or advisory committees; Oncopeptides: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees.

Abstract: Background The role of upfront autologous stem cell transplantation (ASCT) for younger patients with newly diagnosed (ND) multiple myeloma (MM) has been questioned in the novel agent era. Methods A prospective, multicenter, phase III study was designed to compare (first randomization, R1) (1:1 ratio; stratification according to ISS stage) four 42-day cycles of bortezomib-melphalan-prednisone (VMP) given at the same dosing schedule reported in the VISTA study (NEJM 2008; 359:906-17) vs either a single course or two sequential courses of melphalan at 200 mg/m2 (HDM) followed by single or double ASCT, respectively, as intensification therapy after three to four 21-day cycles of induction therapy with bortezomib-cyclophosphamide-dexamethasone and subsequent collection of peripheral blood stem cells. A second randomization (R2) to consolidation therapy with bortezomib-lenalidomide-dexamethasone vs no consolidation was performed after intensification, to be followed by lenalidomide maintenance until progression or toxicity in both arms. A primary study end point was progression-free survival (PFS) from R1. Results From February 2011 to April 2014, 1510 patients aged ≤65 years with symptomatic NDMM were registered. Of these, 1192 were eligible for R1 and were randomly assigned to receive either VMP (n=497 patients) or HDM (1±2 courses) (n=695 patients). Median age was 58 years in both groups, ISS stage III was 21% in VMP and 20% in HDM, while revised ISS stage III was 9% in both groups. Data on cytogenetic abnormalities, as detected by FISH analysis of CD138+ plasma cells, were available in 71% of patients (n=354) randomized to VMP and in 76% of those (n=529) assigned to HDM. The frequency of conventionally defined high-risk cytogenetic changes, including t(4;14) and/or del(17p) and/or t(14;16), was 25% in both arms. Median follow-up from R1 was 26 (IQR: 19-37) months. On an intention-to-treat basis, median PFS was 44 months in the VMP arm and was not yet reached in the HDM arm; 3-year estimates of PFS were 57.5% and 66%, respectively (HR=0.73; 95% CI=0.59-0.90; P=0.003). PFS benefit with HDM was retained across predefined subgroups, including patients with ISS stage I (HR=0.69; CI=0.48-0.98; P=0.037), revised ISS stage II (HR=0.70; CI=0.54-0.91; P=0.008), revised ISS stage III (HR=0.54; CI=0.30-0.97; P=0.040), standard-risk cytogenetics (HR=0.75, CI=0.56-1.01; P=0.055) and a high-risk cytogenetic profile (HR=0.54; CI=0.37-0.80; P=0.002). The probability of achieving a very good partial response or higher quality response was 85.5% in the HDM group vs 74% in the VMP group (odds ratio=1.90; CI=1.42-2.54; P 〈 0.001). In a multivariate Cox regression analysis stratified by ISS, randomization to HDM (HR=0.67; CI=0.53-0.85; P=0.001) and absence of high-risk cytogenetic abnormalities (0.71; CI=0.53-0.95; P=0.021) were the leading independent predictors of prolonged PFS. Overall survival was not yet mature and no difference between the two treatment groups was evident. Detection of minimal residual disease (MRD) after intensification therapy was performed by multiparameter flow cytometry and PET/CT in a subgroup of patients, and details are provided in a separate abstract (E. Zamagni et al). Overall, MRD negativity favorably affected PFS and OS. Conclusions In comparison with VMP as standard-dose intensification therapy, upfront HDM and ASCT significantly improved PFS and increased the rate of high quality responses. An updated analysis with a longer follow-up will be reported at the meeting. Results of this phase III study, the largest so far reported, support the conclusion that upfront ASCT still continues to be the reference treatment for fit patients with NDMM, even in the novel agent era. Disclosures Cavo: Celgene: Honoraria, Research Funding, Speakers Bureau; Janssen: Honoraria, Research Funding, Speakers Bureau; Amgen: Honoraria; Bristol-Myers Squibb: Honoraria; Takeda: Honoraria. Beksac:Celgene, Janssen Cilag Amgen, Novartis, Takeda: Honoraria, Speakers Bureau. Dimopoulos:Genesis: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Gay:Celgene: Honoraria; Amgen: Honoraria; BMS: Honoraria; Takeda: Honoraria, Other: Advisory Board; Janssen-Cilag: Other: Advisory Board; Mundipharma: Other: Advisory Board. Hájek:Janssen: Honoraria; Amgen: Consultancy, Honoraria, Research Funding; Takeda: Consultancy; BMS: Honoraria; Celgene: Consultancy, Research Funding. Mellqvist:Mundipharma: Honoraria; Celgene: Honoraria; Novartis: Honoraria; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Galli:Celgene: Honoraria; Janssen: Honoraria; Sigma-tau: Honoraria. Ludwig:Janssen: Speakers Bureau; BMS: Speakers Bureau; Takeda: Research Funding, Speakers Bureau; Amgen: Research Funding, Speakers Bureau. Zweegman:Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees. Palumbo:Janssen Cilag: Honoraria; Takeda: Employment, Honoraria.

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

Abstract: Background The introduction of proteasome inhibitors (PIs) and immune modulatory drugs (IMiDs) to multiple myeloma (MM) treatment protocols has drastically improved the overall quality and duration of response. This rationalized challenging the role of upfront high dose melphalan (HDM) followed by autologous stem cell transplantation (ASCT) versus chemotherapy alone as intensification treatment in four recent phase III trials. Yet, these showed uniformly that upfront HDM is still superior to non-transplant intensification alternatives including PIs and/or IMiDs. However, HDM's mechanism of action involves induction of interstrand crosslinks and double-strand DNA breaks that cause collateral damage in both healthy cells (toxicity) and tumor cells, which may induce strong selection pressure on the outgrowth of resistant clones at relapse. We therefore hypothesized that certain low-risk patients could save HDM as salvage treatment and that this would improve their overall survival (OS). Methods We chose to combine three robust classification tools in MM that historically have shown a consistent performance across diverse patient cohorts: (1) International Staging System (ISS), (2) deletion of chromosome 17p (del17p) by Fluorescent in Situ Hybridization (FISH) (cutoff ≥10%) and (3) SKY92 high-risk (HR) classifier, based on gene expression profiling (GEP) of MM cells. By combining these scores, we classified ultra-low risk (uLR), intermediate-risk (IR) and HR MM as follows: uLR: ISS = 1, del17p = absent, SKY92 HR = absent. IR: ISS = 2 or 3, del17p = absent, SKY92 HR = absent. HR: ISS = 1, 2 or 3, del17p and/or SKY92 HR = present. The effect of intensification treatment on progression-free survival (PFS) and OS in these risk groups was evaluated in the phase III EMN-02/HOVON-95 MM trial (EudraCT 2009-017903-28). We focused on chemotherapy-naive MM patients aged ≤65 years, who received bortezomib, cyclophosphamide and dexamethasone (3-4xVCD) as induction therapy, followed by randomization 1 (R1) between bortezomib, melphalan and prednisone (4xVMP) and 1xHDM+ASCT, R2 between bortezomib, lenalidomide and dexamethasone (2xVRD) versus no consolidation and lenalidomide maintenance for all. At baseline, bone marrow was collected in the MM biobank at Erasmus MC Cancer Institute, the Netherlands. On this, CD138+ enrichment was performed, followed by a flowcytometric purity check, FISH analysis for del17p and GEP using HG U133 Plus 2.0 arrays (Affymetrix). PFS was defined as the time from R1 to progression or death, whichever occurred first. P-values were not adjusted for multiple testing. Results In our biobank region, 435 patients were randomized between VMP and 1xHDM, of whom ISS data were available for all, del17p status for 87%, SKY92 classification for 41% and all three risk factors for 38% of patients. Of these, 33% were ISS stage I, 47% ISS stage II, 20% ISS stage III, 10% had a del17p and 20% were SKY92 HR. A total of 43 (26%), 83 (50%) and 41 (25%) patients were classified as uLR, IR and HR, respectively. Our risk classification was both significantly associated with PFS (logrank p 〈 1x10-5; 4-year PFS of 64% in uLR, 49% in IR and 24% in HR) and OS (p 〈 1x10-4; 4-year OS of 85% in uLR, 77% in IR and 47% in HR). HR patients had a superior PFS with 1xHDM over VMP (p = 0.003), confirming previous reports. OS was related to intensification arm in both uLR and HR patients, however, in opposite direction: uLR patients treated with VMP had a better OS than those treated with 1xHDM (p = 0.047, 4-year OS of 95% with VMP versus 72% with 1xHDM); whereas OS was better after 1xHDM in HR patients (p = 0.017, 4-year OS of 68% with 1xHDM versus 22% with VMP). We found a significant interaction between intensification treatment and risk group for both PFS (likelihood ratio p = 0.03) and OS (p = 0.005). This indicates that there is indeed a differential treatment effect on survival between risk groups. Conclusions Although our findings are preliminary and need further validation, we are the first to identify a low-risk, transplant-eligible MM subgroup that - in contrast to high-risk MM patients - may benefit from receiving upfront VMP versus 1xHDM+ASCT. Moreover, this illustrates for the first time how combined molecular and clinical subclassification in MM may identify patients that benefit from alternative treatment strategies, such as prolonged bortezomib and lenalidomide. Ultimately, this may result in risk-adapted treatment approaches. Disclosures Beksac: Janssen Cilag: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Deva: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Bristol Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees. Ludwig:BMS: Speakers Bureau; Cilag-Janssen: Speakers Bureau; Celgene: Speakers Bureau; Amgen: Research Funding, Speakers Bureau; Takeda: Research Funding, Speakers Bureau. Kuiper:SkylineDx: Employment. van Vliet:SkylineDx: Employment. Hajek:Takeda: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Bristol-Myers Squibb: Consultancy, Honoraria, Research Funding. Dimopoulos:Janssen: Honoraria; Celgene: Honoraria; Takeda: Honoraria; Amgen: Honoraria; Bristol-Myers Squibb: Honoraria. Palumbo:Takeda Pharmaceuticals Inc.: Employment. Cavo:Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; GlaxoSmithKline: Honoraria, Membership on an entity's Board of Directors or advisory committees; Adaptive Biotechnologies: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees. Sonneveld:Karyopharm: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; BMS: Honoraria, Research Funding.

Abstract: Background The role of up-front consolidation for newly diagnosed, transplant eligible MM (NDMM) patients (pts) has not yet been prospectively addressed in the novel agents era. Methods The EMN02/HO95 trial was designed to randomly (R) compare (R1) 4 cycles of bortezomib-melphalan-prednisone (VMP) vs high-dose melphalan (HDM) and autologous stem cell transplantation (ASCT), either single or double, as intensification therapy after induction with bortezomib-cyclophosphamide-dexamethasone (VCD) (M Cavo et al, ASCO 2016, abstract #8000). A second randomization to consolidation therapy with 2 cycles of VRD vs no consolidation (R2) was performed after intensification, to be followed by lenalidomide maintenance (lenalidomide 10 mg continuously) until progression or toxicity in both arms. (VRD: bortezomib 1.3 mg/m2 intravenously days 1, 4, 8, 11; lenalidomide 25 mg orally days 1 - 21; dexamethasone 20 mg orally days 1, 2, 4, 5, 8, 9, 11, 12 of a 28 days cycle). Primary study end points were progression-free survival (PFS) from R1 and PFS from R2. A first planned interim analysis for R2 was performed in July 2016 when at least 33% (= 172) of the required events for PFS had been observed. Results From February 2011 to April 2014, 1510 pts aged ≤ 65 years with symptomatic MM were enrolled, of whom 1499 were eligible. Of these, 1211 were randomized (stratification by ISS stage) to VMP (505 pts) or HDM (1 or 2 ASCT) (706 pts). For R2 903 eligible patients were randomized to consolidation (459 pts) or no consolidation (444 pts). Median follow up from R2 was 25 months (maximum 53). Response status at time of R2 was ≥ CR (23%), ≥ VGPR (67%), ≥ PR (93%), and will be updated for status at start of maintenance. At the time of analysis, 258 events for PFS after R2 had been reported. 3-year. PFS from R2 was 62% in all patients, i.e., 60% without consolidation and 65% in patients with consolidation, and median PFS had not yet been reached. PFS from R2 with adjustment for R1 was prolonged in pts randomized to VRD (HR=0.78; 95% CI=0.61-1.00; P=0.045), a benefit retained across predefined subgroups with revised ISS stage III (HR=0.67; P=0.26) and in patients randomized in R1 to VMP (HR=0.76; P=0.19) and to HDM (HR=0.79; P=0.13). The benefit of consolidation was observed in patients with low-risk cytogenetics (HR=0.68; P=0.03), but not in patients with high-risk cytogenetics (del(17p) and/or t(4;14) and/or t(14;16); HR=1.03; P=0.91). At 3 years OS from R2 was 86% and 87%, respectively. Toxicity from VRD was limited with 5% CTCAE grade 4, mainly hematological. Conclusions Consolidation treatment with VRD followed by Lenalidomide maintenance until progression or toxicity shows promising results as compared to maintenance alone for younger NDMM pts, but further study follow-up is needed. This trial was registered at www.trialregister.nl as NTR 2528, EudraCT 2009-017903-28 This trial was supported by unrestricted grants from Celgene and Janssen. Disclosures Sonneveld: Celgene: Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Research Funding; Karyopharm: Consultancy, Honoraria, Research Funding; Takeda: Consultancy, Honoraria. Dimopoulos:Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Honoraria, 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; Novartis: Consultancy, Honoraria; Genesis: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Carella:Millenium: Speakers Bureau; Genentech: Speakers Bureau. Ludwig:Janssen: Speakers Bureau; BMS: Speakers Bureau; Amgen: Research Funding, Speakers Bureau; Takeda: Research Funding, Speakers Bureau. Driessen:janssen: Consultancy; celgene: Consultancy; Mundipharma-EDO: Honoraria, Membership on an entity's Board of Directors or advisory committees. Gay:Celgene: Honoraria; Mundipharma: Other: Advisory Board; Amgen: Honoraria; BMS: Honoraria; Janssen-Cilag: Other: Advisory Board; Takeda: Honoraria, Other: Advisory Board. Mellqvist:Mundipharma: Honoraria; Celgene: Honoraria; Novartis: Honoraria; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Zweegman:Celgene: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Takeda: Honoraria, Research Funding. Schjesvold:Janssen: Research Funding; Novartis: Consultancy, Honoraria, Research Funding. Palumbo:Takeda: Employment, Honoraria; Janssen Cilag: Honoraria. Cavo:Celgene: Honoraria, Research Funding, Speakers Bureau; Janssen: Honoraria, Research Funding, Speakers Bureau; Amgen: Honoraria; Bristol-Myers Squibb: Honoraria; Takeda: Honoraria.