ALBERT

Description: Background:Novel insights into the biology of myeloma cells have led to the identification of relevant prognosis factors.Cytogenetic abnormalities (CA) has become one of the most important prognostic factors, and the presence of t(4;14), t(14;16) or del(17p) are associated with poor prognosis. Although there are some reports indicating that 1q gains may be considered as a poor-risk feature, the information is not uniform. Furthermore, there are important controversies about whether or not novel agents-based combinations are able to overcome the poor prognosis of CA. In the relapse setting, the combinations including proteasome inhibitors and immunomodulatory drugs have shown to improve, and some of them to overcome, the outcome of patients with high-risk CA. Here we report a preplanned analysis, in a series of elderly newly diagnosed myeloma patients included in the Spanish GEM2010 trial and receiving VMP and Rd, in a sequential or alternating approach, in order to evaluate the influence of CA by FISH on the response rate and outcome. Patients and methods: 242 pts were randomized to receive a sequential scheme consisting of 9 cycles of VMP followed by 9 cycles of Rd or the same regimens in an alternating approach (one cycle of VMP alternating with one Rd, up to 18 cycles. VMP included the IV administration of weekly bortezomib (except in the first cycle that was given twice weekly) at 1.3 mg/m2 in combination with oral melphalan 9 mg/m2 and prednisone 60 mg/m2once daily on days 1-4. Rd treatment consisted on lenalidomide 25 mg daily on days 1-21 plus dexamethasone 40 mg weekly. FISH analysis for t(4;14), t(14;16), del(17p) and 1q gains was performed at diagnosis according to standard procedures using purified plasma cells. Results: In 174 out of the 233 patients evaluable for efficacy and safety, FISH analysis at diagnosis were available and two groups were identified: high-risk group (n= 32 patients with t(4;14) and/or t(14;16) and/or del(17p)) and standard-risk group (n=142 patients without high-risk CA). The rates of CA was similar in both treatment arms. Response Rates (RR) were no different in the high-risk vs standard-risk groups, both in the sequential (74% vs 79% RR and 42% vs 39% CR) and alternating arms (69% vs 86% RR and 39% vs 38% CR). After a median follow-up of 51 months, high-risk patients showed shorter PFS as compared to standard risk in the alternating arm (24 versus 33 months, p=0.03) and this also translated into a significantly shorter OS (38.4m vs not reached, p=0.002). However, in the sequential arm, high-risk and standard-risk patients showed similar PFS (29.5 months vs 31.5 months, p=0.9) and OS (46m vs 63m, p=0.1). This beneficial effect observed in the sequential arm applied to both t(4;14) or del(17p). As far as 1q gains is concerned, 151 patients had 1q information and 76 of them had 1q gains (50.3%), defined as the presence of more than 3 copies in at least 10% of plasma cells. The rate of 1q gains was well balanced in both sequential and alternating arms. The ORR was similar in patients with or without 1q gains (83% vs 80%) as well as the CR rate (45% vs 31%), and no differences were observed between sequential and alternating arms. Patients with or without 1q gains had a similar PFS (36 months vs 29 months) and 4-years OS (63% vs 68%) in the whole series and no differences were observed between the sequential and alternating arms. This effect has been observed in patients with 1q gains as isolated CA and the outcome was slightly but not significantly worse when 1q gains were present plus either t(4;14) and/or del17p. Conclusions: The total therapy approach including VMP and Rd administered in a sequential approach is able to overcome the poor prognosis of the presence of high-risk CA in elderly patients with newly diagnosed MM. The presence of 1q gains has no impact in the PFS and OS of elderly patients treated with VMP and Rd. Disclosures Mateos: Janssen, Celgene, Amgen, Takeda, BMS: Honoraria. Martínez-López:Novartis: Honoraria, Speakers Bureau. Oriol:Celgene: 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. Paiva:Celgene: Honoraria, Research Funding; Janssen: Honoraria; Takeda: Honoraria, Research Funding; Sanofi: Consultancy, Research Funding; EngMab: Research Funding; Amgen: Honoraria; Binding Site: Research Funding.

Description: Introduction:SMM is an asymptomatic and heterogeneous plasma cell disorder. The Spanish Myeloma Group demonstrated that patients at high risk of progression benefit from early treatment with Rd. In addition, our preliminary results of the curative approach (GEM-CESAR) showed encouraging results (Mateos ASH 2017). Aim: The primary end-point was to evaluate the Minimal Residual Disease negative (MRD-ve) rate by next generation flow (NGF) after induction and ASCT and the sustained MRD-ve rate at 3 and 5 yrs after ASCT as secondary end-points. Our aim was to increase the MRD -ve rate from 34% (reported in NDMM patients after VTD and ASCT) to 50%. As all patients have completed induction and ASCT, we report the results of the primary end point, efficacy and safety after induction and ASCT. Methods: In this phase II single arm trial, 90 SMM patients at high-risk of progression (〉50% at 2 yrs), younger than 70 yrs and transplant candidates were included. The high risk was defined by the presence of both ≥PC 10% and MC ≥3g/dL (Mayo criteria) or ifonly one criterion was present, patients must have a proportionof aberrant PCs within the total PCsBM compartment by immunophenotypingof 95% plus immunoparesis (Spanish criteria). Asymptomatic MM patients with any of the three biomarkers recently included into the definition of active MM were allowed to be included. Induction therapy consisted on six 4-weeks cycles of KRd in which K was given at dose of 36 mg/m2twice per week plus R at dose of 25 mg on days 1-21 and dexamethasone at dose of 40 mg weekly. Melphalan at dose of 200 mg/m2followed by ASCT was given as intensification therapy and three months later, patients received two KRd consolidation cycles followed by maintenance with R at dose of 10 mg on days 1-21 plus dex at dose of 20 mg weekly for up to 2 yrs Results: Between June 2015 and June 2017, the 90 SMM patients at high risk of progression were recruited. Twenty-eight pts (32%) shared at least one of the new biomarkers predicting imminent risk of progression to MM. The primary end point of the trial was met, since 55% of the patients who completed induction and ASCT achieved MRD -ve by NGF (sensitivity 3 x 10-6). Upon analyzing the results after induction, 88 patients completed the 6 induction cycles and were evaluable for response (two patients early discontinued): the ORR was 98% including 41% of ≥CR (32% sCR and 9% CR) and 41% of VGPR rate. Two patients were mobilization failures and one patient rejected ASCT. Two additional patients experienced biological progression before ASCT and went off the study. Eighty-three patients, therefore, proceeded to HDT-ASCT and were evaluable at day +100: the ORR was 100% including ≥CR in 63% of the patients (51% sCR and 12% CR) and VGPR rate in 23%. The MRD-ve rate increased from 31% after induction to 55% with the ASCT. No differences in outcome have been observed according neither to the definition of high risk (Mayo or Spanish model) nor ultra high risk SMM. Concerning toxicity, during induction, G3-4 neutropenia and thrombocytopenia were reported in 5 (6%) and 10 pts (11%), respectively. G3-4 infections were the most frequent non-hematological AE observed in 16 pts (18%), followed by skin rash in 8 pts (9%). One patient reported G1 atrial fibrillation and another cardiac failure secondary to respiratory infection. Three patients reported hypertension (G2 in two and G3 in one). Thirteen patients required lenalidomide dose reduction whilst carfilzomib was not reduced in any patient. In four patients, dexamethasone was reduced. In all but two of the pts, PBSC collection was successful with a median of 4.10 x 106/Kg CD34 cells collected. All patients engrafted. Consolidation and maintenance phases are ongoing. After a median follow-up of 17 months (5-36), 94% of patients remain alive and free of progression and 97% of them alive. Three patients experienced biological progression and discontinued the study: one of them was refractory to the rescue therapies and died and the other two are receiving rescue therapies. One additional patient died early during induction due to a massive ischemic stroke unrelated to the treatment. Conclusions: Although longer follow-up is required, this "curative strategy for high risk SMM" continues being encouraging with an acceptable toxicity profile. The study has met its primary endpoint. The depth of response improved over the treatment: 63% of patients who completed induction and ASCT achieved ≥CR with a MRD-ve rate of 55%. Disclosures Mateos: Takeda: 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; Celgene: 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; Janssen: 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; 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. Rodriguez Otero:Takeda: Consultancy; Celgene: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria; Bristol Myers Squibb: Research Funding; Clínica Universidad de Navarra: Employment. Ocio:AbbVie: Consultancy; Pharmamar: Consultancy; Seattle Genetics: Consultancy; Janssen: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; BMS: Consultancy; Takeda: Consultancy, Honoraria; Sanofi: Research Funding; Amgen: Consultancy, Honoraria, Research Funding; Mundipharma: Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Array Pharmaceuticals: Research Funding. Oriol: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; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Rios:Amgen, Celgene, Janssen, and Takeda: Consultancy. Rosinol:Janssen, Celgene, Amgen, Takeda: Honoraria. Alegre:Takeda: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees. Puig:Janssen: Consultancy, Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Takeda: Consultancy, Honoraria. De La Rubia:Ablynx: Consultancy, Other: Member of Advisory Board. García Mateo:Binding Site: Research Funding; Amgen: Honoraria; Celgene: Honoraria. Bladé:Janssen: Honoraria. Lahuerta:Celgene: 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; Amgen: 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. San-Miguel:Novartis: Honoraria; Janssen: Honoraria; BMS: Honoraria; Amgen: Honoraria; Celgene: Honoraria; Sanofi: Honoraria; Roche: Honoraria.

Description: Background VMP and Rd are two of the most efficient and widely accepted regimens in the treatment of elderly newly diagnosed MM patients. In order to further improve the outcome of elderly patients, one possibility would be to use regimens including all these drugs simultaneously, but this may result into high toxicity. Alternatively, the use of these regimens (VMP and Rd) in a sequential or alternating scheme could improve the treatment of elderly patients. We hypothesized the alternating scheme would minimize the emergence of resistant clones, and would reduce the cumulative toxicity. In order to test this hypothesis we decided to compare VMP and RD in a sequential vs an alternating scheme. Patients and methods 241 patients were randomized to receive a sequential scheme consisting on 9 cycles of VMP followed by 9 cycles of Rd or the same regimens in an alternating approach (one cycle of VMP alternating with one Rd (half of the patients started by VMP and half by Rd) up to 18 cycles). VMP included the iv administration of bortezomib 1.3 mg/m2 twice weekly for 1 six-weeks cycle, followed by once weekly for 8 four-weeks cycles in combination with oral melphalan 9 mg/m2 and prednisone 60 mg/m2 once daily on days 1–4 of each cycle. Rd treatment consisted on lenalidomide 25 mg daily on days 1-21 plus dexamethasone 40 mg weekly. Results 121 patients were allocated to receive the sequential scheme and 120 the alternating regimen. Both arms were well balanced according to the baseline characteristics. 52% patients in the sequential arm and 55% in the alternating and had high risk cytogenetic abnormalities (t(4;14), t(14;16), del17p or 1q gains). After 9 cycles of treatment, in the sequential arm, 35 out of 66 (54%) achieved at least VGPR vs 51 out of 65 patients (78%) in the alternating arm (p=0.002), including sCR/CR rate of 28% vs 38% in the sequential and alternating arms, respectively (p=NS). Seven patients in each arm achieved immunophenotypic CR. Moreover, while four patients progressed in the sequential arm under treatment with VMP, no patients in the alternating scheme developed disease progression during the first 9 cycles, After a median follow up of 12 months, there was a trend for shorter TTP in the sequential as compared with the alternating scheme (18 m-TTP of 83% vs 89% (p=NS)). In terms of OS, 83% of patients in the sequential arm were alive at 18 m versus 93% in the alternating (p=NS). Patients who achieved sCR/CR had a significantly longer 18 m-TTP as compared with patients who didn’t achieve it in both sequential (100% vs 71%; p=0.006) and alternating arms (100% vs 79%; p=0.006) and this translated into a significant benefit in OS. No differences were observed in overall response rates and CR rates in standard and high risk patients. The 18 m-TTP was similar in standard and high risk groups in both sequential (86% vs 81%) and alternating arms (84% vs 94%), noting that 94% of patients receiving the alternating scheme were progression-free at 18 months. Regarding hematologic toxicity, the frequency of G3-4 neutropenia was slightly lower in the sequential than in the alternating arm (16% and 23%) and the same trend was observed for G3-4 thrombocytopenia (16% vs 20%). Concerning non-hematologic toxicity, 5% and 4% of the patients in the sequential and alternating arms developed G3-4 infections, respectively; the rate of G3-4 skin rash was 4% in the sequential and 3% in the alternating arm; 4% of patients in the sequential arm developed G3-4 peripheral neuropathy and 3% in the sequential arm. The rate of grade 3-4 thrombotic events was 2% in both arms. Nevertheless, the detailed evaluation of the toxicity will be done at the completion of the trial when all patients will have received the same amount of drugs in either a sequential or an alternating scheme (at the present time, 42 patients in the sequential arm were not yet at risk for the development of lenalidomide-related side effects). Conclusions The administration of melphalan, bortezomib, lenalidomide and steroids in elderly MM patients in a sequential or alternating scheme is feasible. Although longer follow-up is necessary, the alternating scheme may be superior in terms of response rate and outcome, as result of the early exposure of the plasma cell to different agents. Toxicity profile is acceptable. Aparently both schemes of therapy seems to overcome the poor prognosis of high risk cytogenetic. Disclosures: Mateos: Janssen, Celgene: Honoraria. Off Label Use: Lenalidomide plus dexamethasone is not approved for newly diagnosed MM patients. Ocio:Onyx: Consultancy, Research Funding; Novartis: Consultancy; Array Biopharma: Consultancy, Research Funding; Bristol Myers Squibb: Consultancy; Celgene: Consultancy, Research Funding. San Miguel:Janssen, Celgene: Membership on an entity’s Board of Directors or advisory committees.

Description: Abstract 3962 Introduction: In April 2006, the Spanish Myeloma Group (PETHEMA/GEM) activated a randomized phase III trial comparing induction with TD vs. VTD vs. VBMCP/VBAD/Bortezomib (VBMCP/VBAD/B) in patients 65 years-old or younger with newly diagnosed symptomatic MM and ASCT with MEL-200 followed by maintenance with thalidomide/bortezomib (TV) vs. thalidomide (T) vs. alfa-2b-interferon (alfa2-IFN). Primary end points : response rate after induction and after ASCT and time to progression. Patients and Methods: The maintenance program consisted of TV (thalidomide 100 mg daily plus one cycle of bortezomib-1.3 mg/m2 on days 1, 4, 8 and 11 every 3 months) versus T (single agent thalidomide at a dose of 100 mg daily) versus alfa2-IFN (subcutaneous alfa2b-IFN at a dose of 3 MU three times per week). The planned maintenance duration was three years or until disease progression or toxicity. From February 1, 2007 to January 27, 2011 266 patients were randomized to maintenance therapy (TV:90; T: 89, alfa2-IFN: 87). Response and survival were evaluated on an intention-to-treat basis. Responses and progressions reported by the investigators were centrally reassessed. Results: the patient's characteristics at diagnosis such as age, ISS stage, cytogenetics and presence of extramedullary plasmacytomas as well as induction regimen (VTD, TD and VBMCP/VBAD/Bortezomib) and diagnosis-randomization interval were similarly distributed among the 3 arms. The response status at the time of randomization after ASCT was CR: 51%, VGPR: 23%, PR: 24% and SD: 2% and was well balanced in the three groups. The CR rate with maintenance was improved by 23% with TV, 11% with T and 19% with alfa2-IFN (p=NS). After a median follow-up of 24 months, the PFS was significantly longer with TV compared with T and alfa2-IFN (PFS at 2 yrs: 78% vs. 63% vs. 49%, p=0.01). However, OS was not significantly different among the 3 arms. Grade 3 and 4 hematological toxicity was similar (22.2% vs. 16% vs. 21.8%). No peripheral neuropathy (PN) was observed with alfa2-IFN being its frequency similar with TV (12.2%) and T (10.1%). No grade IV PN was observed. Dose reductions for TV, T and alfa2-IFN were required in 33.3%, 33.7% and 19.5% of the patients, respectively. The discontinuation rate due to toxicity was significantly higher with thalidomide compared with TV (30.3% vs. 15.6%, p= 0.08) and with alfa2-IFN (30.3% vs. 18.3%, p= 0.17). Conclusion: the addition of bortezomib to thalidomide maintenance resulted in a significantly longer PFS when compared with thalidomide alone or with IFN with no increased toxicity. Disclosures: Rosiñol: Janssen: Honoraria; Celgene: Honoraria. Cibeira:Janssen: Honoraria; Celgene: Honoraria. Mateos:Janssen: Honoraria; Celgene: Honoraria. Martinez:Janssen: Honoraria; Celgene: Honoraria. de la Rubia:Janssen: Honoraria; Celgene: Honoraria. Díaz-Mediavilla:Janssen: Honoraria; Celgene: Honoraria. Alegre:Janssen: Honoraria; Celgene: Honoraria. Lahuerta:Janssen: Honoraria; Celgene: Honoraria. San Miguel:Millennium Pharmaceuticals, Inc.: Membership on an entity's Board of Directors or advisory committees; Janssen-Cilag: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees. Blade:Janssen: Honoraria; Celgene: Honoraria.

Description: Abstract 4952 Background Current clinical observations on extramedullary myeloma (EM) are based on small series of relapsed myeloma patients (pts) and, in this situation, results suggest that the disease course is often aggressive. Among novel therapies for extramedullary involvement, thalidomide has provided poor results and bortezomib is emerging as a possible useful drug. The role of lenalidomide for treatment of multiple myeloma (MM) with EM is still under investigation. Aim A multicenter retrospective study was performed by PETHEMA (Spanish Myeloma Group, Spain) to evaluate the response rate and toxicity profile of lenalidomide-based regimens in myeloma patients with extramedullary involvement at relapse or progression. All the cases were evaluated for response of MM and improvement of extramedullary plasmacytoma. Patients and Methods From October 2007 to March 2009, thirteen patients (median age 67 years; range 61–87; 7 females) treated with lenalidomide-containing regimens were recorded. Patients with bone disease without extramedullary manifestations were excluded. Response of MM was evaluated according to the new international criteria and the response of EM by measuring size changes by physical examination, CT scans and/or MR imaging. Adverse events were graded based on the WHO toxicity scale. The M-protein type was IgG in 7 cases, IgA in 5 and light chain in 1. The type of light chain was κ in 7 pts and l in 6. In eight patients the soft-tissue plasmacytomas may have developed from underlying bone lesions [(skull (n=2), rib cage (n=4) and paravertebral (n=2)], two patients had subcutaneous nodules and three had visceral involvement (liver (n=1), lung and kidney (n=1) and pleura (n=1). Multiple localizations were present in 4 pts (30.7%). Six cases (79.6%) received previous antimyeloma treatment for EM before lenalidomide therapy and the incidence of prior bone plasmacytomas was 61.5%. Median time from initial antimyeloma therapy to treatment with lenalidomide was 34 months (range 5 - 115). Median number of prior lines of chemotherapy regimens was 3 (range 1 – 4), including autologous stem cell transplantation in 2 pts, bortezomib-containing regimens in 12 (92.3%) and previous exposure to thalidomide in 1 patient. Ten pts received standard lenalidomide dose (25 mg/day every 4 weeks) plus dexamethasone (40 mg/d PO ranging from 1 to 12 doses/cycle) every 3-week; and three patients received lower doses of lenalidomide and/or different schedules. Involved-field radiotherapy was given in 2 cases. Thirty percent of patients required lenalidomide dose reduction, because of toxicity or intolerance. Results Median duration of lenalidomide treatment was 3.6 months (1 – 15). One case was not evaluable for response because of death from disease progression after one cycle. In nine out of twelve evaluable patients (75%), MM responded to lenalidomide regimens according to EBMT criteria. Three (25%) achieved complete response, five (41.6%) partial response and 1 (8.3%) minimal response. Median time to response was 63 days (range 37 – 180). Regarding EM, nine patients showed response in the size of extramedullary plasmacytomas. Seven (58.3%) achieved complete disappearance of EM and two pts reduction of the size. Response of EM was also achieved in 75% of pts previously exposed to bortezomib, and in 4/9 cases who received therapies for prior extramedullary involvement. Median follow-up period was 6.3 months (1 – 15.8). Median overall survival from the start of lenalidomide therapy was 4.7 months. At the time of analysis, seven patients were still on therapy, and ten (76.9%) were alive. Only one out of the 9 patients who had achieved a response has relapsed so far. Toxicity profile (grade 3/4) was: thrombocytopenia, 4 (30.7%); anemia, 2 (15.3%); neutropenia, 5 (46.4%); neutropenic fever, 1 (7.6%) and others, 3 (11.8%). No deep venous thrombosis (DVT) was reported. Thrombosis prophylaxis was used in most cases (92%) patients. Conclusions We report one of the first investigations specifically evaluating the activity of lenalidomide on EM. Lenalidomide-containing regimens could be an alternative promising approach to achieve clinical response in heavily treated MM patients with extramedullary disease. The duration of response and the best regimen or combination are at present unknown. These preliminary observations require further analysis and longer follow-up. Disclosures No relevant conflicts of interest to declare.

Description: Abstract 5044 Introduction: Epidemiological studies are the base to evaluate the efficiency of medical interventions in the interest of the public health. Updated epidemiological data and effectivenes in the daily clinical practice are needed in Multiple Myeloma (MM). Materials and Methods: Epidemiological retrospective, longitudinal, multicenter nation wide Spanish study of an historical cohort of patients with MM. Data from patients aged ≥ 18 years, with a MM Stage II or III, who received a treatment on a daily clinical practice (not in clinical trials) for MM in the September'03-August'05 time frame were collected. The study protocol was approved by an Ethics Committee in 2009. Data were collected in 37 Spanish Centres during a 6 months period. Stratified effectiveness and survival analysis were performed (age

Description: Background: MM usually affects elderly patients and although novel agents-based combinations have substantially improved MM outcome, it is possible that this benefit would be particularly relevant for the "youngest-elderly" patients (65-80y). According to the frailty score published by IMWG, the chronological age ≥80 years identifies itself a frail patient population with poor outcome and we have here evaluated the efficacy, safety and outcome of patients included in the GEM2010 trial according to the age to identify the group of patients who benefit most of this total therapy approach. Patients and methods: 242 patients were randomized to receive a sequential scheme consisting on 9 cycles of VMP followed by 9 cycles of Rd or the same regimens in an alternating approach (one cycle of VMP alternating with one Rd, up to 18 cycles. VMP included the iv administration of weekly bortezomib (except in the first cycle that was given twice weekly) at 1.3 mg/m2 in combination with oral melphalan 9 mg/m2 and prednisone 60 mg/m2 once daily on days 1-4. Rd treatment consisted on lenalidomide 25 mg daily on days 1-21 plus dexamethasone 40 mg weekly. Results: 233 pts were evaluable for safety and efficacy (118 in the sequential and 115 in the alternating arm). One hundred and fifteen patients (49%) were between 65-75 years, 69 patients (30%) were aged between 75-80 years and 49 patients (21%) were older than 80 years. The allocation in both sequential and alternating arms was well balanced. There were not significant differences in the baseline characteristics of the three subgroups of patients. The ORR was similar in both patients aged 65-75 and 75-80 (80% and 83%), but significantly lower in patients older than 80 years (68%) (p=0.007). The CR rate was also almost identical in patients between 65-75 (45%) and 75-80 (49%), but significantly lower in those aged over 80 years (10%) (p

Description: Abstract 617 Disappearance of normal bone marrow (BM) plasma cells (N-PC) predicts malignant transformation of monoclonal gammopathy of undetermined significance (MGUS) and smoldering myeloma (SMM) into symptomatic myeloma (MM). The homing, behavior and survival of N-PC, but also CD34+ hematopoietic stem/precursor cells (HPC), B-cell precursors, and (mono)clonal/aberrant PC (M-PC) largely depends on their interaction with SDF-1 expressing BM stromal cell niches. Accordingly, it can be hypothesized that a certain degree of competition among BM B-cell precursors, CD34+ HPC, and PC exist for the same BM niches. Thus, progressive replacement of normal cells by M-PC could help to explain the occurrence of cytopenias and hypogammaglobulinemia in MM patients. However, this hypothesis has not been investigated in depth neither in MM nor in SMM and MGUS. In this study we analyze by 8-color multiparameter flow cytometry the distribution and competitive migration capacity of B-cell precursors, CD34+ HPC, N-PC and M-PC in the BM and PB of patients with MGUS (n=60), SMM (n=47) and MM (n=87) at diagnosis plus 12 MM cases studied after high-dose therapy/autologous stem cell transplantation (MM POST-HDT/ASCT) vs. healthy adults aged 〉60 years (HA; n=26). The percentage of BM M-PC as well as the number of M-PC from all BMPC found at diagnosis significantly (p.05) and SMM (p〉.05). Despite the number of N-PC in the BM was significantly lower among MM and SMM vs. MGUS cases (p.05 vs. HA). Interestingly however, the proportion of CXCR4+ PB N-PC progressively increased from HA (11%) to MGUS (14%), SMM (15%) and MM (21%; p=.05 vs. HA), while MM POST-HDT/ASCT cases showed the lowest median percentage of CXCR4+ PB N-PC (5%). CD34+ HPC were found to be depleted in the BM of MM (0.3%; p=.001) and SMM (0.4%; p=.002) patients vs. HA (0.9%) while MGUS (0.8%) and MM POST-HDT/ASCT (1.1%) patients showed normal CD34+ HPC numbers. Conversely, PB CD34+ HPC progressively increase from HA to MGUS, SMM and MM cases (p=.008 and p=.06 vs. HA, respectively). By contrast, in MM POST-HDT/ASCT patients the number of PB CD34+ HPC returned to normal/lower levels. Ex-vivo competition assays between BM B-cells, PC and CD34+ HPC for SDF-1 induced migration showed that in HA, CD34+ HPC displayed the highest migration potential in the presence of SDF-1, followed by pre-B cell precursors; conversely N-PC barely migrated. No significant differences were found for the migration of all cell populations analyzed between MGUS and SMM patients vs. HA, except for M-PC that showed an impaired migration in the presence of SDF-1. In turn, the migration potential of CD34+ HPC (p=.04), and pre-B cell precursors (p=.02) was markedly reduced in symptomatic MM, particularly at lower SDF-1 concentrations (30nM). Most interestingly, the migration of M-PC from symptomatic MM was markedly increased at both concentrations of SDF-1 used: median of 2.9% and 1.0% for SDF-1 concentrations of 30nM and 70nM, respectively. Overall, these findings provide evidence about the role of progressive competition and replacement of normal BM cells by M-PC in determining transformation of pre-malignant MGUS and SMM into symptomatic MM. Disclosures: No relevant conflicts of interest to declare.

Description: Introduction: In MM, there is growing body of evidence showing the importance of MRD monitoring particularly among transplant-eligible patients. However, it is perhaps in elderly MM, the major patient subgroup and in which optimal balance between efficacy and toxicity is critical, that sensitive response assessment could help to tailor patients' treatment. Methods: We used an 8-color second-generation flow assay to monitor MRD among elderly MM patients (n=163) included in the PETHEMA/GEM2010MAS65 trial (sequential chemotherapy with 9 cycles of bortezomib-melphalan-prednisone (VMP) followed by 9 cycles of lenalidomide-low dose dexamethasone (Rd), or alternating cycles of VMP and Rd up to 18 cycles). A single 8-color antibody combination (CD45-PacB/CD138-OC515/CD38-FITC/CD56-PE/CD27-PerCPCy5.5/CD19-PECy7/CD117-APC/CD81-APCH7) was used to detect phenotypically aberrant clonal plasma cells (PCs), and MRD-negativity was defined when

Description: BACKGROUND: The first step to the cure of Multiple myeloma (MM) is achieving a clinical complete response (CR). However, a majority of patients relapse in part due to the persistence of low levels of pathological plasma cells after treatment (minimal residual disease (MRD)). In previous work, we have shown that Next generation sequencing (NGS) of immunoglobulin (IG) rearranged genes is an effective technology to identify and quantify pathological clonal cells in MM, and also it is a good predictor of patient prognosis. However, this technology is a proprietary multiplex PCR, uses a reference plasmid, it is performed at the centralized laboratories, and it is not broadly available. AIMS: To present a new in-house simplified method for quantification of IG gene clonal rearrangements by NGS. To test the suitability of the method for MRD detection in MM patients compared with 8-color high sensitivity Flow Cytometry (8c-MFC) data on a prospective way. To determine its capability as a predictor of patient prognosis. METHOD: We use deep sequencing to prospectively analyzed DNA from bone marrow samples of 58 patients (58 diagnostic samples and 80 follow-up samples) of patients included the GEM10 clinical trial. The method employs the primers developed by BIOMED-2 for IGH and IGK, and a set of specific mathematical and bioinformatics tools. First, we identified the clonal rearrangement(s) (clonotype) in the diagnostic sample by fragment analysis and NGS. Second, we searched the NGS sequences from follow-up samples to detect and quantitate (MRD) the presence of the clonotype identified in the diagnostic sample. Overall Survival (OS) and Progression free Survival (PFS) were estimated by Kaplan-Meier survival analysis. The survival curves generated were compared with the log-rank test for trend. RESULTS: The sensitivity of the method is 10-5 for 150.000 cells. Reproducibility is 〉90%. The Spearman correlation coefficient between NGS and 8c-MFC data for diagnosis and follow-up samples was R=0.6903, p10-5) by 8c-MFC but negative (10-5 vs not reached for patients with values of MRD