Abstract: Background: MRD is an established biomarker to evaluate treatment efficacy, define patients at risk based on persistent MRD, and eventually, act as surrogate for prolonged survival based on sensitive MRD-negative definitions. Accordingly, the IMWG has developed criteria for MRD-negativity defined by next-generation sequencing, NGF or PET/CT, and has recommended their inclusion in clinical trials. Notwithstanding, most flow cytometry results have been obtained using less sensitive methods and in fact, there is no data about the impact of NGF-based MRD assessment in clinical trials. Aim: To define the feasibility, sensitivity and clinical impact of NGF-based MRD assessment in the phase III PETHEMA/GEM2012 trial. Methods: A total of 458 patients were enrolled into the PETHEMA/GEM2012 trial. MRD was predefined to be prospectively assessed at three time-points: after six induction cycles with bortezomib, lenalidomide, and dexamethasone (VRD), after HDT/ASCT, and after two courses of consolidation with VRD. MRD monitoring was performed blinded for clinical outcomes in four PETHEMA/GEM laboratory cores, and data was centralized for MRD analyses. MRD assessment was performed following EuroFlow SOPs in a total of 1,134 bone marrow (BM) samples from 419 patients. The 39 cases without MRD assessment had suboptimal response to induction and were thus considered as MRD+ for intention-to-treat analyses. Noteworthy, in 14 BM samples with undetectable MRD, B-cell precursors, erythroblasts and mast cells represented & lt;0.01% of BM cells, and these samples were thus considered as hemodiluted and inadequate for MRD assessment. The limit of detection (LOD) was determined for each of the 1,117 BM samples representative for MRD assessment, according to the formula: (20/nucleated viable cells) x 100; the median LOD achieved by NGF in the PETHEMA/GEM2012 trial was of 3x10-6. Results: Overall, 225/458 (49%) patients had undetectable MRD at the latest time-point in which MRD was assessed and were thus classified as MRD-. Conversely, 233/458 (51%) cases remained MRD+: 28% with ≥10-4 MRD, 12% with 10-5 MRD, and 11% with 10-6 MRD. Detailed analyses of MRD kinetics in 320 patients with available MRD results at all three time-points, showed that the percentage of MRD- patients increased from 35% into 54% and 58% after induction, HDT/ASCT and consolidation, respectively. Furthermore, a restricted analysis among MRD+ patients showed that whereas after induction only 8% of them had MRD levels as low as 10-6, subsequent intensification with HDT/ASCT and consolidation could reduce MRD levels down to 10-6 in 32% of MRD+ cases. Progression-free survival (PFS) rates at 3-years were of 92%, 70%, 54% and 44% for patients being MRD-negative, MRD+ 10-6, 10-5 and ≥10-4, respectively (P & lt;.001; Figure). Thus far, only 6/225 (3%) MRD- patients have relapsed; strikingly, all 6 cases had extramedullary plasmacytomas at diagnosis, all relapsed with extramedullary plasmacytomas, and only 2 had concomitant serological relapse. The favorable outcome of MRD- patients encouraged us to investigate the impact of MRD negativity in both standard- and high-risk patients defined by FISH [i.e.: t(4;14), t(14;16), and/or del(17p)]. Even though MRD- rates were significantly inferior in patients with high- vs standard-risk FISH (37% vs 50%, respectively; P=.03), 3-year PFS rates were similar between patients with high- and standard-risk FISH reaching MRD-negativity (94% and 91%, respectively; P=.56); by contrast, MRD+ cases with high- and standard- risk FISH had median PFS of 27 and 35 months, respectively (P=.025). Conclusions: This is the largest study of MRD monitoring in MM based on the total number of samples analyzed (n=1,134). Our results show that NGF-based MRD assessment is feasible in large multicenter clinical trials, is highly-sensitive, and allows the identification of hemodiluted BM samples inadequate for MRD assessment. Risk of relapse among MRD-negative patients was remarkably reduced (3%), and was particularly related to the reappearance of extramedullary plasmacytomas, which urges the need for combined cellular and imaging MRD monitoring in these patients; by contrast, even MRD levels as low as 10-5 and 10-6 conferred significantly inferior PFS. Overall, this study defines MRD-negativity as the most relevant clinical endpoint for both standard- and high-risk transplant-eligible MM patients. Figure Figure. Disclosures Paiva: Sanofi: Consultancy, Honoraria, Research Funding; Janssen: 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, Research Funding; Amgen: Honoraria; Merck: Honoraria; Novartis: Honoraria; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; EngMab: Research Funding. Oriol: Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: sponsored symposia, Speakers Bureau; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: sponsored symposia, Speakers Bureau; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: sponsored symposia; Celgene: Speakers Bureau. de la Rubia: Janssen: Other: Honoraria; Amgen: Other: Honoraria; Celgene: Other: Honoraria. Rosinol: Celgene: Honoraria; Janssen: Honoraria. Mateos: Amgen: 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; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Lahuerta: Amgen: Honoraria; Celgene: Honoraria; Janssen: Honoraria. San Miguel: Roche: Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Consultancy, Membership on an entity's Board of Directors or advisory committees; MSD: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: 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; Takeda: 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; Sanofi: 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.

Abstract: Background: The randomized PETHEMA/GEM phase III trial GEM05menos65 (www.clinicaltrials.gov NCT00461747) demonstrated that pretransplant induction therapy with VTD resulted in a significantly higher CR rate both, pretransplant and postransplant and in a significantly longer progression-free survival (PFS) when compared with thalidomide/dexamethasone (TD) and combination chemotherapy plus bortezomib (VBMCP/VBAD/B) (Rosiñol et al, Blood 2012). We report here the long-term results of the trial, five years after the last patient was included. Methods: From April 6, 2006 to August 5, 2009, 386 patients younger than 65 years with newly diagnosed symptomatic multiple myeloma (MM) were randomized to receive three different induction regimens: six 4-week cycles of TD (thalidomide 200 mg daily; dexamethasone 40 mg on days 1-4 and 9-12) vs. six 4-week cycles of VTD (TD at identical doses plus i.v. bortezomib 1.3 mg/m2 on days 1, 4, 8 and 11) vs. combination chemotherapy plus bortezomib (4 cycles of alternating VBMCP and VBAD chemotherapy followed by two cycles of i.v. bortezomib at the usual dose of 1.3 mg/m2 on days 1,4,8,11 every 3 weeks). The duration of the induction therapy was 24 weeks in all arms. All patients were planned to undergo ASCT with high-dose melphalan at 200 mg/m2 followed by maintenance therapy with thalidomide/bortezomib (TV) vs. thalidomide (T) vs. alfa-2b-interferon (alfa2-IFN) for 3 years. One-hundred and thirty patients were allocated to VTD, 127 to TD and 129 to VBMCP/VBAD/B. Seventy out of the 330 patients (21%) with cytogenetic studies had high-risk cytogenetics [t(4;14), t(14;16) and/or 17p deletion]. Patient characteristics at diagnosis and prognostic factors such as ISS, cytogenetics and maintenance arm were similarly distributed in the 3 arms. Results: After a median follow-up of 70.6 months, VTD resulted in a significantly longer PFS when compared with TD and VBMCP/VBAD/B (56.1 vs 29.2 vs 39.9 months, p=0.005) (Figure 1). The estimated overall survival (OS) at 8 years was 60% with no significant differences among the 3 arms. In the overall series, the PFS was significantly shorter in patients with high-risk cytogenetics compared with patients with standard-risk (15.7 vs. 44.3 months, p=0.003). In the TD and in the VBMCP/VBAD/B arm patients with high-risk cytogenetics had a significantly shorter PFS than patients with standard-risk (8.9 vs 32.8 months, p=0.04 in TD group; 14.1 vs. 43.3 months, p=0.05 in VBMCP/VBAD/B group). However, there was no significant difference in the VTD arm (23.6 vs 56.1 months, p=0.2). Patients with high-risk cytogenetics had a significantly shorter OS in the overall series (median 42.1 months vs not reached, p=0.00001) and this was observed in the three treatment arms: VTD median 37.1 months vs not reached (p=0.001), TD median 54.2 months vs not reached (p=0.06), VBMCP/VBAD/B median 30.2 months vs not reached (p=0.007). The achievement of a deeper response at the end of induction was associated with a longer PFS and OS. Thus, patients achieving CR at the end of induction had a significantly longer PFS than patients achieving a lower degree of response (median 62 vs. 28 months, p=0.00001), irrespective of the treatment arm. Furthermore, on an intention to treat basis, patients who were in postrasplant CR had a significantly longer PFS (p 〈 0.00001) and OS (p 〈 0.00001) than those who did not reach CR after ASCT (p 〈 0.001). In the overall series the OS after progression was 30.5 months and was not significantly different among the 3 arms (VTD 25.4 months, TD 50 months, VBMCP/VBAD/B 30.2 months, p=0.4). Patients with high-risk cytogenetics had a significantly shorter OS after relapse in the overall series (13.3 months vs. 37.5 months, p=0.001), in the VTD arm (13.3 vs 33.9, p=0.01) and in the VBMCP/VBAD/B arm (8.5 vs 38 months, p=0.01). Conclusions: Our long-term results confirm that induction with VTD results in a significantly longer PFS when compared with TD and VBMCP/VBAD/B. Patients with high-risk cytogenetics had a worse outcome even with the use of novel drugs. Finally, the PFS of 56 months achieved with VTD is the longest ever reported in the first line treatment of younger patients with MM elegible for ASCT and support the use of VTD as the standard of care for pretransplant induction therapy. Figure 1: PFS according to the induction arm Figure 1:. PFS according to the induction arm Disclosures Rosiñol: Janssen: Honoraria; Celgene: Honoraria. Oriol:Celgene Corporation: Consultancy. De La Rubia:Janssen: Honoraria; Celgene: Honoraria. Gutierrez:Janssen: Honoraria; Celgene: Honoraria. Martinez-Lopez:Janssen: Honoraria; Celgene: Honoraria. Alegre:Janssen: Honoraria; Celgene: Honoraria. Lahuerta:Janssen: Honoraria; Celgene: Honoraria. San Miguel:Janssen: Honoraria; Celgene: Honoraria.

Abstract: Background: Renal failure (RF) is present in about 20% of patients with newly diagnosed multiple myeloma (MM) and is associated with a poor outcome. Bortezomib-based therapy has shown significant activity in patients with RF, including a higher rate of renal recovery when compared with previous regimens. We report the results of a prospective phase II trial for patients with newly diagnosed MM and RF treated with bortezomib and dexamethasone (VD) (RENVEL: www.clinicaltrials.gov NCT 01084837). Aim: The primary end-point was efficacy in terms of response rate and secondary end-points were recovery of RF, PFS and OS. Patients and Methods: Patients with newly diagnosed MM and renal failure from 11 PETHEMA institutions were included. RF was defined as an estimated filtration glomerular rate (eFGR) 〈 50 ml/min calculated by the MDRD formula. Patients 〈 66 years were treated with 4 cycles of i.v. bortezomib 1.3 mg/m2 on days 1, 4, 8 and 11 and dexamethasone 40 mg p.o. on days 1-4 and 9-12 every 3 weeks and those with no other comorbidities than RF were planned to received high-dose melphalan followed by stem cell rescue (ASCT group) . Patients ³66 years or younger with comorbidities not candidates to high-dose therapy received up to 8 cycles of VD. Responding patients with no significant toxicities were given 4 additional cycles at the same dose of bortezomib and dexamethasone 40 mg on days 1-4 at 4-weeks intervals (no ASCT group). Myeloma response was assessed by the IMWG criteria and renal response by the criteria recently proposed (Dimopoulos et al, J Clin Oncol 2010;33:4976-4984). Results: Between April 9, 2010 and September 13, 2012, 60 patients (42 M, 18F, median age 72 years) were enrolled. The M-protein type was IgG in 14 patients, IgA in 22, light-chain only (Bence-Jones) in 22 and IgD in 2. 85% of the patients had ISS 3 and 19% had high-risk cytogenetics. The median baseline eFGR was 17 ml/min and 40 patients had severe RF defined as eFGR 〈 30 ml/min. Seventeen patients (28%) required initial renal replacement with dialysis. The overall response rate in the overall series was 75% (29%CR, 27% VGPR, 19% PR, 3% MR, 16% refractory disease, 5% early death, 1% non-evaluable). Eighteen patients (30%) were initially considered candidates to receive ASCT. The overall response rate after 4 induction cycles was 77% (28% CR, 23% VGPR, 28% PR, 5% MR, 16% refractory disease). Seven patients did not proceed to ASCT because of progressive disease (4), renal impairment with poor PS (2) and lost of follow-up (1). The response rate of the 11 patients who underwent to ASCT was CR in 8 patients (73%), VGPR in 1 (9%), PR in 1 (9%) and early death (sepsis) in 1 (9%). Grade 3 toxicity was only observed in 3 patients. No patient developed grade 3-4 neurological toxicity and only 2 patients had grade 2 peripheral neuropathy. Forty-two patients (70%) were not candidates to receive ASCT. The median number of cycles administered was 7.5. The overall response rate was 71% (29% CR, 29% VGPR, 14% PR, 2% MR, 17% refractory disease, 7% early death, 2% non-evaluable). 15 patients discontinued therapy because of bortezomib-related toxicity and seven were discontinued due to infectious complications. One patient developed grade 3 thrombocytopenia and grade 3 extrahematological toxicity was observed in 4 patients (gastrointestinal, asthenia, Wernicke-Korsakoff and rash one patient each). Peripheral neuropathy was observed in 18 patients (grade 2: 13 patients, grade 3: 5 patients). Renal response was achieved in 66% of the patients (29% CR, 14% PR, 23% MR). The median time to renal respose was 1.6 months (0.8-2.7). Therteen patients out of 17 (76%) could have been discontinued from dyalisis. The renal response rate was similar in the two groups. After a median follow-up of 26.7 months, the median PFS in ASCT and no-ASCT groups was 33.3 and 16.3 months, respectively. The estimated OS at 36 months were 82% and 72%, respectively. In both groups the PFS was not significantly different among patients achieving renal response vs. those not achieving renal response. In no-ASCT group the OS was significantly longer in patients achieving renal response compared with patients not achieving renal response (not reached vs. 35.3 months, p=0.03). Conclusions: VD is a highly effective regimen in patients with newly diagnosed multiple myeloma and severe renal failure, resulting in a high quality tumor responser and a renal response rate of 66% including a 76% of dialysis discontinuation. Disclosures Rosiñol: Janssen: Honoraria; Celgene: Honoraria. Oriol:Celgene Corporation: Consultancy. Mateos:Janssen: Honoraria; Celgene: Honoraria. De La Rubia:Janssen: Honoraria; Celgene: Honoraria. Jiménez:Janssen: Honoraria. Lahuerta:Janssen: Honoraria; Celgene: Honoraria. San Miguel:Janssen: 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; Onyx: Honoraria, Membership on an entity's Board of Directors or advisory committees; Millenium: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees. Blade:Janssen: Honoraria; Celgene: Honoraria.

Abstract: Initial results of the Spanish GEM2005mas65 phase III trial comparing VMP versus VTP as induction therapy in elderly patients with newly diagnosed MM did not show any difference in terms of OS or PFS. The purpose of this study was to update clinical results with a longer follow-up. Secondary objectives were to know the patterns of symptomatic relapse and response to therapy in patients previously exposed to novel agents. Methods GEM2005mas65 trial lasted from March, 2006, and October, 2008. Overall, 260 patients with untreated MM, 65 years and older, from 63 Spanish centres, were randomly assigned to receive six cycles of VMP (n=130) or VTP (n=130) as induction therapy followed by maintenance therapy with bortezomib plus prednisone (n=87) or bortezomib plus thalidomide (n=91). Results With a median follow-up of 53.2 months, median OS of the entire cohort of patients was 42.45 months. Median OS was 62 months in patients receiving VMP versus 42.6 months in patients receiving induction with VTP (P = 0.045) (Figure 1). No differences were observed in PFS, being 31 and 24.4 months in the VMP and VTP groups, respectively. At the time of the study, 167 patients had relapsed or progressed and 92 of them received some kind of post relapse treatment. Front-line therapy and clinical and biological characteristics at the time of relapse in this subgroup of patients are summarized in Table 1. Initial induction treatment consisted of VMP in 40 (43.4%) patients and VTP in 52 (56.5%) patients. Overall, after induction and maintenance therapy 66 (71.7%) patients had been exposed to bortezomib and thalidomide and 26 (28.2%) patients received bortezomib-based therapy without immunomodulatory agents before relapse. At symptomatic relapse, median age was 74 years (range 65-87) and 43 (46.7%) were male. Serum creatine level 〉 2 mg/dL was present in 11.9% of the patients and 4.3 % had hypercalcemia. Extramedullary disease and plasma cell leukemia was present in 17% and 4.4% of patients, respectively. Finally, severe bone disease was observed in 39 the patients. Management of relapse was very heterogeneous. Subsequent drugs used in first clinical relapse included lenalidamide combinations in 40 (43.4%) patients, bortezomib-based therapy in 19 (20.5%) patients, different chemotherapy combinations in 25 (27.1%) patients and bendamustine-prednisone in 2 (2.1%) patients. Six (6.5%) patients received only supportive at time of first relapse. Overall, 45 (52%) patients achieved partial response or better after rescue therapy. Response rates were higher after lenalidomide-based therapy (62.5%) when compared with bortezomib (42.1%) and conventional chemotherapy-based regimens (40.7%),although this difference did not translate into significant PFS advantage. After a median follow-up of 16.4 months (range 0-50.2) from clinical relapse,58 (63%) patients had died. Median PFS and OS were 10 (CI95%; 10.7-50.2) and 15.6 months (CI95%; 8.5-16.5%), respectively. In patients initially treated with VMP (n = 40) and VTP (n =52) median survival from start of subsequent therapy was 15.6 and 15.4 months, respectively. Among characteristics at relapse, only ISS stage had an impact on survival (P= 0.03).There was no difference in OS or PFS from front-line induction and/or maintenance therapies or salvage therapy. Conclusions This updated analysis of the GEM2005mas65trial shows a survival advantage of the VMP arm when compared with patients receiving VTP. Patterns of relapse were similar regardless previous induction and maintenance therapy. Finally, and when analyzing the subgroup of patients receiving active therapy at relapse, only ISS stage seemed to have a prognostic impact on OS. Group A: VMP, group B : VTD Disclosures: Mateos: Janssen, Celgene, Onyx, Millennium, Mundipharma: Honoraria. Oriol:Celgene: Consultancy. Off Label Use: Bendamustine, bortezomib and prednisone is a combination not approved for newly diagnosed myeloma patients.

Abstract: In April 2006, the Spanish Myeloma Group (PETHEMA/GEM) initiated a randomized phase III trial (GEM05menos65) comparing induction with thalidomide/dexamethasone (TD) vs. bortezomiv/thalidomide/dexamethasone (VTD) vs. VBMCP/VBAD/Bortezomib (VBMCP/VBAD/B) in patients 65 years-old or younger with newly diagnosed symptomatic MM followed by ASCT with MEL-200 and maintenance therapy with interferon vs, thalidomide alone or bortezomib/thalidomide. The results of the overall series has been previously published. However, the efficacy of novel agents in patients with extramedullary disease is not well stablished. Primary end points to describe the characteristics and outcome of patients with EMPs homogeneously treated in the GEM05menos65 trial. Patients and Methods TD consisted of thalidomide 200 mg daily (escalating doses in the first cycle) and dexamethasone 40 mg on days 1-4 and 9-12 at 4-week intervals for 6 cycles. The VTD regimen was identical to TD plus i.v. bortezomib 1.3 mg/m2 on days 1,4,8,11 of each cycle. Combination chemotherapy plus bortezomib consisted of 4 cycles of VBMCP/VBAD on an alternating basis followed by 2 cycles of i.v. bortezomib (1.3 mg/m2 on days 1,4,8, and 11 every 3 weeks). The duration of the induction therapy was 24 weeks in all arms. From April 6, 2006 to August 5, 2009 the 390 planned patients entered the study. 66 patients (17%) had extramedullary plasmacytomas (median age: 54 years, M: 33, F: 33). The isotype was IgG: 41, IgA 11, Bence-Jones: 10, IgD:4; kappa:41, lambda: 25.The stage according to the ISS was I in 27 patients, II in 26 and III in 13 patients. The location of the EMPs was soft-tissue masses arising from lytic lesions in 60 patients, testicular mass with no contact with bone in 1 case and was not specified in 6 cases. Nine patients had multiple extraosseous plasmacytomas. 17 patients received induction therapy with VBMCP/VBAD/B, 23 with TD and 26 with VTD. Results Cytogenetic information was available in 51 out of the 66 cases with EMPs and 12 of them (23%) showed high-risk cytogenetics. There were no differences in the incidence of high-risk cytogenetics (t(4;14), t(14;16) and del 17p) in patients with and without EMPs (23% vs 21%). The incidence of t(4;14) in patients with and without EMP was 16% vs 23%, respectively. The incidence of del 17p was 10% and 6% in patients with and without EMPs.The IFE negative CR rate was significantly higher with VTD as compared to TD (42% vs 13%, p=0.02) while there was no significantly differences among VTD and VBMCP/VBAD/B (42% vs 29%, p=NS). Patients with EMP had a significantly higher rate of PD during induction therapy as compared to patients without EMPs (24% vs 11%, p=0.01). This higher rate of PD in patients with EMP was observed in the 3 induction arms (VBMCP/VBAD/B 24% vs 9%, TD 40% vs 19%, VTD 12% vs 6%). 43 patients received ASCT as part of the treatment design. On an intention to treat basis, the pos-ASCT CR rate was higher with VTD arm compared to TD (50% vs 22%, p=0.07) but not significantly different from VBMCP/VBAD/B (50% vs 41%, p=0.7). After a median follow-up of 46 months, there was no significant differences in PFS between patients with or without EMP (26.9 vs 39.9 months, p=0.47). Although the difference did not reach statistical significance, there was a trend towards a shorter PFS for patients with EMPs with high-risk cytogenetics (median 12.1 vs. 28.3 months, p=0.13). In patients with EMPS, the PFS was not reached in the VTD arm versus 26.9 months with VBMCP/VAB/B and 22.8 moths with TD. The OS was significantly shorter in patients with EMPs as compared to patients without EMPs (median 69.9 months vs not reached, p=0.02) Conclusion 1) In the present study the frequency of EMPs was 17%, 2) the incidence of high-risk cytogenetics in patients with EMPs was similar to that observed in patients with no extramedullary disease, 3) patients with EMPs had a higher rate of progressive disease irrespective of the induction arm as compared to patients without EMPs, being VTD the best treatment option, 4) finally, the OS was significantly shorter in patients with EMPs. Disclosures: Rosiñol: Janssen: Honoraria; Celgene: Honoraria. De La Rubia:Janssen: Honoraria; Celgene: Honoraria. Mateos:Jansen: Honoraria; Celgene: Honoraria. Tomas:MedImmune: Research Funding. Gutiérrez:Jansen: Honoraria; Celgene: Honoraria. San Miguel:Celgene: Consultancy, Honoraria, Membership on an entity’s Board of Directors or advisory committees; Janssen: Consultancy, Honoraria, Membership on an entity’s Board of Directors or advisory committees; Millenium: 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; Onyx: Consultancy, Honoraria, Membership on an entity’s Board of Directors or advisory committees. Lahuerta:Janssen: Honoraria; Celgene: Honoraria. Blade:Janssen: Honoraria; Celgene: Honoraria.

Abstract: Background: Autologous stem-cell transplantation (ASCT) is the standard of care for younger patients with multiple myeloma (MM). The degree of tumor reduction after ASCT is the crucial factor associated with a prolonged PFS and OS, being the M-protein decrease at the time of transplant the most important predictor of residual disease after ASCT. While there is an agreement that bortezomib and dexamethasone associated to a third drug is the induction of choice, which should be the third drug (thalidomide, lenalidomide, doxorubicin or cyclophosphamide) and the optimal number of cycles remain unknown. The results of phase 3 PETHEMA study GEM05menos65 showing a CR rate of 35% increasing overtime during the 6 induction cycles of VTD (Rosiñol et al, Blood 2012) prompted us to study the kinetics of response to VTD and TD in this study and in similar historic data with the VD regimen in phase 2 PETHEMA VELCA/DEXA trial (Rosiñol et al, JCO 2007). Objective: To study the kinetics of response by cycle during the 6 cycles of induction with VTD, TD and VD using a random effects model methodology. Patients and Methods: In GEM05menos65 study patients were randomized to receive 6 induction cycles of either VTD or TD followed by ASCT. One hundred and thirteen patients were treated with TD (thalidomide 200 mg daily; dexamethasone 40 mg on days 1-4 and 9-12) and 122 with VTD (TD at identical doses plus bortezomib 1.3 mg/m2 on days 1, 4, 8 and 11) (Rosiñol et al, Blood 2012) and had complete data set for this analysis. In VELCA/DEXA study 40 patients received 6 induction cycles of bortezomib and dexamethasone on an alternating basis (Rosiñol et al, JCO 2007). Linear random effects models were employed to analyze the tumor response kinetics using the absolute decrease value of the serum M-protein after each cycle. Because the nonlinearity in the change of the M-protein overtime, a piecewise linear model was used to estimate mean changes in M-protein in each of the 6 cycles. Results: Three different comparisons were made: 1) the decrease of the M-protein by cycle within each treatment group, 2) the total M-protein decrease at the end of induction with VTD compared to TD and VD and 3) the decrease by cycle comparing VTD vs TD and VTD vs VD. Concerning the M-protein decrease by cycle within each arm, statistically significant decreases versus the previous cycle were observed in the first 5 cycles of VTD, the first 3 of TD and the first 4 of VD. The serum M-protein reduction at the end of the 6 induction cycles was significantly higher with VTD when compared with TD (p 〈 0.0001) and VD (p 〈 0.0001). Finally, when comparing the serum M-protein decrease between VTD and TD by cycle, the M-protein reduction was significantly higher with VTD in the first 5 cycles and the same analysis between VTD and VD showed that the serum M-protein decrease was significantly higher with VTD in the first 3 cycles (Tables 1 and 2). Conclusions: In the cycle by cycle analysis VTD continued to improve M-protein reduction significantly in the first 5 cycles. When compared with TD and VD, the M-protein decrease at the end of induction was significantly higher with VTD. Furthermore, in the cycle by cycle comparison there was a significantly higher efficacy of VTD over TD in the first 5 cycles and over VD in the first 3 cycles. Our results suggest a synergistic rather than only an additive effect between thalidomide and bortezomib supporting the use of an IMiD as the drug of choice to be combined with bortezomib and dexamethasone. Finally, our study supports an induction period beyond 3 or 4 cycles when using a bortezomib/IMiD regimen in order to maximize the induction efficacy. Table 1. Comparison between VTD versus TD by cycles overtime. Serum M-protein (g/dl) Change (VTH-TH) Estimate SE 95% CI P-value C1 – Baseline -3.0747 0.3461 (-3.7539, -2.3954) 〈 .0001 C2 – C1 -1.1343 0.1294 (-1.3883, -0.8802) 〈 .0001 C3 – C2 -0.4474 0.09586 (-0.6356, -0.2593) 〈 .0001 C4 – C3 -0.2140 0.08224 (-0.3753, -0.05257) 0.0094 C5 – C4 -0.1339 0.07550 (-0.2821, -0.01428) 0.0765 C6 – C5 0.01862 0.05395 (-0.08725, 0.1245) 0.7300 Table 2. Comparison between VTD versus VD by cycles overtime. Serum M-protein (g/dl) Change (VTH-VD) Estimate SE 95% CI P-value C1 – Baseline -3.1553 0.2243 (-3.5957, -2.7150) 〈 .0001 C2 – C1 -1.3748 0.2279 (-1.8223, -0.9272) 〈 .0001 C3 – C2 -0.4266 0.2354 (-0.8887, 0.03552) 0.0703 C4 – C3 -0.05473 0.2439 (-0.5337, 0.4242) 0.8225 C5 – C4 -0.02217 0.2530 (-0.5189, 0.4745) 0.9302 C6 – C5 0.06493 0.2908 (-0.5060, 0.6358) 0.8234 Disclosures Rosiñol: Janssen: Honoraria; Celgene: Honoraria. Oriol:Janssen: Honoraria; Celgene: Honoraria. De La Rubia:Janssen: Honoraria; Celgene: Honoraria. Gutierrez:Janssen: Honoraria; Celgene: Honoraria. Mateos:Janssen: Honoraria; Celgene: Honoraria. Martinez-Lopez:Janssen: Honoraria; Celgene: Honoraria. Alegre:Janssen: Honoraria; Celgene: Honoraria. Feng:Janssen: Employment. van de Velde:Janssen: Employment. Lahuerta:Janssen: Honoraria; Celgene: Honoraria. San Miguel:Janssen: Honoraria; Celgene: Honoraria. Blade:Janssen: Honoraria; Celgene: Honoraria.

Abstract: Background: The randomized PETHEMA/GEM phase III trial GEM05menos65 (www.clinicaltrials.gov NCT00461747) demonstrated that pretransplant induction therapy with VTD resulted in a significantly higher CR rate both, pretransplant and postransplant and in a significantly longer progression-free survival (PFS) when compared with thalidomide/dexamethasone (TD) and combination chemotherapy plus bortezomib (VBMCP/VBAD/B) (Rosiñol et al, Blood 2012). We report here the definitive results of the trial, ten years after the last patient was included. Methods: From April 6, 2006 to August 5, 2009, 386 patients younger than 65 years with newly diagnosed symptomatic multiple myeloma (MM) were randomized to receive three different induction regimens: six 4-week cycles of TD (thalidomide 200 mg daily; dexamethasone 40 mg on days 1-4 and 9-12) vs. six 4-week cycles of VTD (TD at identical doses plus i.v. bortezomib 1.3 mg/m2 on days 1, 4, 8 and 11) vs. combination chemotherapy plus bortezomib (4 cycles of alternating VBMCP and VBAD chemotherapy followed by two cycles of i.v. bortezomib at the usual dose of 1.3 mg/m2 on days 1,4,8,11 every 3 weeks). The duration of the induction therapy was 24 weeks in all arms. All patients were planned to undergo ASCT with high-dose melphalan at 200 mg/m2 followed by maintenance therapy with thalidomide/bortezomib (TV) vs. thalidomide (T) vs. alfa-2b-interferon (alfa2-IFN) for 3 years. One-hundred and thirty patients were allocated to VTD, 127 to TD and 129 to VBMCP/VBAD/B. Seventy out of the 330 patients (21%) with cytogenetic studies had high-risk cytogenetics [t(4;14), t(14;16) and/or 17p deletion]. Patient characteristics at diagnosis and prognostic factors such as ISS, cytogenetics and maintenance arm were similarly distributed in the 3 arms. Results: After a median follow-up of 115 months for alive patients, VTD resulted in a significantly longer PFS when compared with TD and VBMCP/VBAD/B (52 vs 28 vs 32 months, p=0.01) (Figure 1). The median overall survival (OS) was 128 vs 99 vs 93 months, respectively, with no significant differences among the 3 arms. In the overall series, the PFS was significantly shorter in patients with high-risk cytogenetics compared with patients with standard-risk (15 vs. 42 months, p=0.001). In the TD and in the VBMCP/VBAD/B arm patients with high-risk cytogenetics had a significantly shorter PFS than patients with standard-risk (7 vs 32 months, p=0.029 in TD group; 13 vs. 38 months, p=0.027 in VBMCP/VBAD/B group). However, there was no significant difference in the VTD arm (23 vs 52 months, p=0.125). Patients with high-risk cytogenetics had a significantly shorter OS in the overall series (median 38 months vs 114, p=0.0001) and this was observed in the three treatment arms: VTD median 36 months vs not reached (p=0.0001), TD median 52 months vs 113 (p=0.017), VBMCP/VBAD/B median 29 months vs 93 (p=0.01). The achievement of a negative MRD after transplant was associated with a longer PFS and OS. Thus, on an intention to treat basis, patients who had MRD negative after transplant had a significantly longer PFS (59 vs 38 months, p=0.0001) and OS (median not reached vs 102 months, p=0.001) than those who remained MRD positive after ASCT. Of interest, there are no significant differences in PFS (41 months vs 60 months, p=0.367) or OS (114 moths vs not reached, p=0.329) between patients with high-risk or standard risk cytogenetics who achieved negative MRD after transplant. By contrast, in patients with MRD positive after transplant, the PFS ( 16 months vs 38 months, p=0.006) and OS (29 months vs 113 months, p=0.001) was significantly shorter in patients with high-risk cytogenetics compared with patients with standard-risk cytogenetics. Conclusions: Our long-term results confirm that induction with VTD results in a significantly longer PFS when compared with TD and VBMCP/VBAD/B. Patients with high-risk cytogenetics who achieved postransplant MRD negative had a similar outcome than patients with standard-risk cytogenetics, while patients with high-risk cytogenetics who remain MRD positive had a dismal prognosis. Finally, the PFS of 52 months achieved with VTD is the longest ever reported in the first line treatment of younger patients with MM elegible for ASCT and support the use of VTD as the standard of care for pretransplant induction therapy. Figure 1. Figure 1. Disclosures Rosinol Dachs: Amgen: Honoraria; Celgene: Honoraria; Janssen: Honoraria. Oriol:Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Blanchard:Janssen: Honoraria. Granell:Janssen: Honoraria; Celgene: Honoraria. Mateos:GSK: Consultancy, Membership on an entity's Board of Directors or advisory committees; 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; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: 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; GSK: 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. Martinez-Lopez:Celgene: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Vivia: Honoraria; Pfizer: Research Funding; BMS: Research Funding; Novartis: Research Funding. Alegre:Celgene: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees. Lahuerta: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; 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. San-Miguel:BMS: Honoraria; Roche: Honoraria; Sanofi: Honoraria; Celgene: Honoraria; Amgen: Honoraria; Janssen: Honoraria; Novartis: Honoraria. Blade:Amgen: Honoraria; Celgene: Honoraria; Janssen: Honoraria.

Abstract: Abstract 3435 Background: Albeit of well-known, dramatic improvements, there remain some questions to be solved around Ph+CML in treatment with tyrosine kinase inhibitors (TKI). Among these, the significance of the amount of minimal residual disease (MRD) measured by RT-PCR. For instance, loss of a so-called major molecular response (MMR) is claimed to be a Òsuboptimal responseÓ and following the ELN recommendations, a change in treatment should be considered in these patients. Aims: To evaluate the relevance of a loss of MMR in patients with complete cytogenetic response (CCR). Study Group and Methods: We have analized 81 patients treated with imatinib for CML in chronic phase with a median follow up of 66 months. 36 patients started imatinib after interferon failure and 45 as front line therapy. Major Molecular Response (MMR; BCR-ABL/ABL ratio 〈 0.1% IS) at any time was achieved by 63 patients. Results: 22 patients (34%) lost MMR (documented al least twice). The risk of losing MMR was higher in late MMR ( 〉 18 months) compared with those cases whose MMR came much earlier ( 〈 18 months): 70% vs 18% (p=. 000). We have found no correlation among the lost of MMR and classical prognostic factors (Sokal-Index, mutations at the TK domain or imatinib plasma levels). Of these 22 patients, 7 (32 %) recovered MMR later with no therapy changes, 8 (36%) experienced fluctuations in the BCR-ABL transcript-levels without losing CCR, 4 (19%) did not attain a MMR but remained in stable CRR, and 3 (13%) lost CCR. These regained MMR after being treated on second generation TKI. The results show how the stability of the early MMR is greater than late MMR (table1). Conclusions: In our experience, one third of the patients who lost MMR recovered it later on the same treatment. And only 13% went on to treatment failure. Perhaps some similar cases (after first losing MMR) should be closely monitored before a change in treatment. Also of note is, of course regarding only our experience, that the risk of a loss of MMR seems to be maximal in patients who achieve a late MMR. Disclosures: No relevant conflicts of interest to declare.

Abstract: Abstract 5049 Background. Treatment of frail or elderly patients with relapsing symptomatic/active Multiple Myeloma (MM) is very difficult due to concomitant diseases, impaired bone marrow reserve, systemic toxicity, relatively decreased renal function and general problems of old age. Dexamethasone and new agents (thalidomide, lenalidomide, bortezomib and bendamustine) have been used in this setting, in most cases with doses adapted to the clinical situation. Aims. To retrospectively analyze the management of frail and/or very elderly MM patients with relapsed and active disease treated with reduced doses of the aforementioned agents in five hospitals in Madrid, Spain. Methods. The files of this group of MM patients were studied. The most common treatment has been the combination of low doses of lenalidomide (len) and of dexamethasone (dex), whereas treatment with reduced doses of other agents has been anecdotal; therefore we analyzed the results of len/dex combinations. Len and dex have been used in lower than standard doses, adapted to the individual initial situation of the patients and tailored according to effect and toxicity throughout treatment. There was no specific protocol and the management of the patients has depended exclusively on the practice and criteria of the treating physicians. Patient risk was stratified following the Salmon and Durie (S & D) score and the International Staging System (ISS). Response was assessed with the IMWG criteria. The study has been approved by the Ethics Committee of Hospital Ramon y Cajal, as coordinating center. Results. 38 patients were included in the study. Mean age was 79 years (range 68–90). 30 pts (79%) were older than 75 years and 10 pts had over 85 years. More than half of the patients (21) had two or more comorbidities. Patients had previously received 1 to 5 (m=1. 8) different treatment modalities, including steroids, melphalan (25), bortezomib (20), thalidomide (6) (or their combinations), and others or even APBSCT (3). 23 pts (60%) had IgG (m=4087 mg/dl, range 868–13000); 13 (34%) IgA (m=2115, range 355–4930) and 2 (5%) only light chains. 22 had κ and 15 λ light chains. 19 (50%) had BJ proteinuria. Mean Hemoglobin level was 10. 7 gr/dl (7. 5–14. 1) and mean creatinine level 1. 3 mg/dl (0. 4–12. 9); 28 (74%) had bone disease. 3 pts had S & D stage I, 22 stage II, and another 13 stage III. 13 pts had ISS stage I, 17 had stage II and 7 stage III. Patients received between 1 and 30 cycles of len/dex (m= 8). Median initial Len dose was 10 mg, the majority between 5 and 15mg, although 4 received 25 mg that were rapidly reduced. Mean initial dex dose was 20mg/day for 4 days. 4 pts (10. 5%) achieved Complete Remission (CR) (3 with negative IF), 27 (71%) Partial Remission (PR) (5 with VGPR) and 2 (5%) a significant, but lesser than 50%, reduction of the M-component (Stable Disease, Std). Altogether, overall response (CR+PR+Std) occurred in 33 pts (86%). The best response occurred after 2 to 9 cycles (m=4) of len/dex. Treatment was stopped in 15 patients due to neurological (4) or hematological (1) toxicity, pulmonary embolism (1), unrelated causes (4) and after achieving a plateau response (5). Time to next treatment was 1–30 months, (m=8 mo). 7 pts relapsed after 3–21 months (m=7). 10 patients died, 5 of related (disease progression, cardiac amyloidosis, renal progression to ESRF) and 5 of unrelated (cancer, sepsis, myocardial infarction, congestive heart failure) causes. Grade III-IV bone marrow toxicity occurred in 9 pts and neurological toxicity (PNP) in 5 (all of them had previously been treated with bortezomib or thalidomide). Conclusions. Personalized low doses of len/dex have been the most common treatment for frail/very elderly patients with relapsed MM in our centers and it is an active and tolerable option in this setting. The haematological toxicity was expectable and manageable, but prior treatments with bortezomib or thalidomide were associated with limiting neurotoxicity. Disclosures: No relevant conflicts of interest to declare.