Abstract: We analyzed cytogenetic data at diagnosis in 395 primary myelofibrosis (PMF) patients to evaluate any possible association between karyotype and WHO 2017 classification and its impact on prognosis. All the cases were diagnosed and followed at five Italian Hematological Centers between November 1983 and December 2016. An abnormal karyotype (AK) was found in 69 patients and clustered differently according to bone marrow fibrosis grade as it was found in 31 (27.0%) cases with overt fibrotic and 38 (13.6%) with pre‐fibrotic PMF ( p = 0.001). Sex, anemia, thrombocytopenia, circulating blasts ≥1%, higher lactate dehydrogenase, and International Prognostic Scoring System risk classes were all significantly associated with karyotype. At a median follow‐up of 〉 6 years, 101 deaths were recorded. Survival was different between AK and normal karyotype (NK) patients with an estimated median overall survival (OS) of 11.6 and 25.7 years, respectively ( p = 0.0148). In conclusion, in our cohort around 20% of patients had an AK, more frequently in subjects with an advanced bone marrow fibrosis grade and clinical‐laboratory features indicative of a more aggressive disease. This study shows that an AK confers a more severe clinical phenotype and impacts adversely on OS, thus representing an additional parameter to be considered in the evaluation of PMF prognosis.

Abstract: Despite the improvement in survival outcomes, multiple myeloma (MM) remains an incurable disease. Chimeric antigen receptor (CAR) T-cell therapy targeting B-cell maturation antigen (BCMA) represents a new strategy for the treatment of relapsed/refractory MM (R/R). In this paper, we describe several recent advances in the field of anti-BCMA CAR T-cell therapy and MM. Currently, available data on anti-BCMA CART-cell therapy has demonstrated efficacy and manageable toxicity in heavily pretreated R/R MM patients. Despite this, the main issues remain to be addressed. First of all, a significant proportion of patients eventually relapse. The potential strategy to prevent relapse includes sequential or combined infusion with CAR T-cells against targets other than BCMA, CAR T-cells with novel dual-targeting vector design, and BCMA expression upregulation. Another dark side of CART therapy is safety. Cytokine release syndrome (CRS) andneurologic toxicity are well-described adverse effects. In the MM trials, most CRS events tended to be grade 1 or 2, with fewer patients experiencing grade 3 or higher. Another critical point is the extended timeline of the manufacturing process. Allo-CARs offers the potential for scalable manufacturing for on-demand treatment with shorter waiting days. Another issue is undoubtedly going to be access to this therapy. Currently, only a few academic centers can perform these procedures. Recognizing these issues, the excellent response with BCMA-targeted CAR T-cell therapy makes it a treatment strategy of great promise.

Abstract: Introduction Lenalidomide (Len) and low-dose Dexamethasone (dex) (Rd) in continuous is a new standard of care for elderly newly-diagnosed multiple myeloma (NDMM) patients (pts), as established by FIRST trial (Facon et al, Blood 2018). Methods and results This is a retrospective, multicentric study conducted in Italy with the aim of evaluating efficacy and tolerability of Rd in a real-life population. Thirty-seven centers were involved and data of 429 pts are available. Pts were considered eligible for the study when completing at least 2 cycles of Rd regimen. Table 1 summarizes the characteristics of pts at time of MM diagnosis. Median age was 78 years (range 57-92), 36.6% had an ECOG PS≥2, creatinine clearance (ClCr) was 〈 30 ml/min in 7.1% of pts. 16, 30 and 54% resulted respectively fit, unfit and frail by IMWG Frailty score. ISS was respectively I, II and III in 27.5, 40.5 and 32% while R-ISS was I, II and III in 31.8, 42.4 and 25.8% of pts. t(4;14), t(14;16), del(17p) or amp(1q) by FISH were respectively found in 9.2%, 5.5%, 5.8% and 36.6% of pts. Extramedullary disease (EMD) was documented in 11% of pts. After a median follow-up of 11 months, most pts are still on treatment (60,4%), the median number of administered cycles was 7 (range 2-33). Overall response rate (ORR, ≥PR) was 74.5% with 34.1% of pts obtaining at least a VGPR. Clinical Benefit Rate (CBR, including minimal responses) was 83.3%. Responses were rapid with median time to first and to best response respectively of 1.8 (range 1-8) and 5 (1-26) months. Median OS and PFS were not reached with a 1-y and 2-y OS of 84.8 and 73.8% and a 1-y and 2-y PFS of 78.6 and 65%. Median EFS was 19.8 months. In univariate analysis, factors significatively impairing ORR were frailty (fit/unfit/frail 91.2/77/55.9%, p 〈 0.001), ECOG (0-1/ 〉 2 81.7/61.6%, p 〈 0.001), presence of t(4;14) (52.9 vs 76.7%, p=0.033) and amp(1q) (53.4 vs 83.5, p 〈 0.001), R-ISS (3 vs 2-1 55.3 vs 72.6%, p=0.027), LDH 〉 upper level of normal (ULN) (65.8 vs 77%, p=0.034). 1-y PFS is significantly shorter in pts with lower ECOG (0-1 vs 2, 66.5 vs 84.8%, p 〈 0.001), higher frailty score (fit/unfit/frail 100/86.4/66.6%, p=0.01), higher ISS (I-II-III 88.4-79.1-68.5%, p=0.002) and R-ISS (I-II-III 75.5-88-50.5% p=0.02), LDH 〉 ULN (66.4 vs 83.2%, p=0.02), lower ClCr ( 〈 30/30-50/ 〉 50 57.2/81.3/80.1%, P=0.01), presence of t(14;16) (42.9 vs 80.4% p=0.01) and amp(1q) (63.5 vs 85.6%, p=0.01); factor impairing OS are ECOG (0-1/ 〉 2 93.4 vs 69.4%, p 〈 0.001), frailty (fit/unfit/frail 100/90.5/75.3% p=0.001), higher ISS (I-II-III 93.6/87.8/74.6%, p=0.006) and R-ISS (I-II-III 87/93/72%, p 〈 0.001)), LDH 〉 ULN (75.1 vs 97.1, p=0004), impaired ClCr ( 〈 30/30-50/ 〉 50 64/83.7/88.2%, p 〈 0.001); EFS was affected by ECOG (0-1/ 〉 2 74.2 vs 47.3%, p 〈 0.001), frailty (fit/unfit/frail 83.4/74.5/52% p=0.09), R-ISS (I-II-III 61.4/74.9/37.5% p=0.006), presence of t(14;16) (35.5 vs 67.8% p=0.08) or amp(1q) (50.1 vs 69% p=0.02). In multivariate analysis ORR is significantly correlated with ECOG 〉 2 (p=0.05), LDH 〉 ULN (p=0.005) and presence of amp1q (p=0.006); PFS was significantly affected by R-ISS III (p=0.04), LDH 〉 ULN (P=0.01) and ClCr 〈 30 (p=0.006) and EFS by R-ISS III (p=0.002); only ECOG 〉 2 still impact on OS (p 〈 0.0001) Dose reduction of Len or dex was required respectively in 20.7% and 22.1% and 39.2% needed cycle delay for adverse events (AEs). Grade 3-4 (G3-4) AEs occurred in 52% of pts with 30.9 and 36.6% having at least a hematological or extra-hematological G3-4 AE. In particular, 17.9 and 16.6% of pts had severe neutropenia and anemia while the most common non-hematological AEs were infections (25.8%, G3-4 12.2%), mainly involving respiratory tract (71.2%). Gastroenteric and cutaneous AEs were quite common (22.1 and 19.2%), mainly diarrhea and itching, but in the vast majority were mild. G3-4 asthenia was present in 22.8% of pts. Although 99% of pts was given antithrombotic prophylaxis, 8.5% had a thromboembolic event, a third of severe entity. G-CSF and EPO analogs were required in 27.4 and 26% of pts. Conclusion Real-life data confirm efficacy and tolerability of Rd in elderly NDMM pts. Performance status by ECOG and IMWG frailty score and severe renal impairment but not age itself act as limiting factors affecting outcome. These data must be confirmed by longer follow-up. Disclosures Conticello: Celgene: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Research Funding. Mangiacavalli:Janssen cilag: Consultancy; celgene: Consultancy; Amgen: Consultancy. Zambello:Celgene: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees. Belotti: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. Molteni:Celgene: Membership on an entity's Board of Directors or advisory committees. Aquino:Celgene: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees. Del Fabro:Janssen: Consultancy. Galli:Leadiant (Sigma-Tau): Honoraria; Janssen: Honoraria; Bristol-Myers Squibb: Honoraria; Takeda: Honoraria; Celgene: Honoraria.

Abstract: Abstract 1851 Background: Bendamustine, an agent sharing properties of alkylators and purine analogous, showed a strong efficacy and safe toxicity profile in relapsed multiple myeloma (MM) patients (pts), with a maximally tolerated dose (MTD) ranging from 100 mg/m2/die day 1 and 2 as single agent to 60 mg/m2/die in association with thalidomide. In a pooled analysis of two large phase 3 trials Lenalidomide, an analogous of thalidomide with strong activities in MM, significantly improved overall response rate and progression-free survival. Since the role of Lenalidomide in the treatment of naïve and relapsed/refractory pts has been well established, the current research is focused on the combination of Lenalidomide with chemotherapy to further improve patient outcome. Methods: This multicenter phase I/II trial was designed to investigate the combination of Bendamustine, Lenalidomide, and Dexamethasone (BdL) in repeating 4-week cycles as treatment for relapsed MM. Pts over 18 years with measurable stage II or III MM who relapsed after 1 to 3 previous lines of therapy, including bone marrow transplantation were considered eligible. Prior Lenalidomide and Bortezomib were allowed. The phase I study was conducted using a 3+3 cohort design beginning at a dose level 0 of intravenous Bendamustine 40 mg/m2/die days 1 and 2, oral Lenalidomide 10 mg/die days 1–21 and oral Dexamethasone 40 mg/die days 1, 8, 15, and 22 (28-day cycle). The dose of Bendamustine and Lenalidomide (from 0 to 5) were increased from one cohort to the next, in a 3+3 dose escalation scheme to reach the MTD (Table 1). The MTD of Bendamustine and Lenalidomide were evaluated during the first treatment course (cycle 1). Enrollment at each subsequent dose level was permitted only if the first 3 patients at the previous level received 1 cycle with an acceptable dose-limiting toxicity (DLT). DLTs were defined as any adverse event (AE) possibly related to the study drug ≥grade 3 CTC. If 1 of the 3 subjects experienced DLT during the first cycle, 3 more subjects were to be recruited and treated at the same dose level of Bendamustine and Lenalidomide. Treatment was given until plateau of best response according to the International Myeloma Working Group uniform response criteria for a maximum of 6 cycles. Results: Herein, we present the results from phase I of the study which established MTD. Fifteen pts with a median age of 69 years (range 49 to 88) were enrolled between October 2011 and February 2012. The number of prior therapies was at maximum 3 as per protocol: Lenalidomide (27% of pts), thalidomide (33% of pts), Bortezomib (67% of pts) and 13% of the pts had a prior autologous stem cell transplant. Because 3 DTL were observed in Phase I, the MTD was set at 40 mg/m2/die for Bendamustine and 10 mg/die for Lenalidomide. DLTs at dose level 1 included: 1 grade 4 cutaneous rash; at dose level 2: 1 grade 4 thrombocytopenia and 1 grade 3 bronchopneumonia with renal dysfunction (Table 2). Among the 15 patients with evaluable data, the grade 3 or 4 AEs observed in ≥10% of patients included neutropenia (20%), thrombocytopenia (13%) and anemia (20%). Two patients died of treatment-related complications: 1 for hematological toxicity and CNS hemorrhage, and 1 for cardiac ischemia. Fifteen patients received at least 2 cycles and were included in the response assessment. The overall response rate was 40% with 1 case achieving complete response and 1 a very good partial response. Until now 7 pts entered the phase II part of the trial. Conclusions: In pretreated patients with relapsed MM, MTD was determined to be Bendamustine 40 mg/m2/die on days 1 and 2, and Lenalidomide 10 mg/m2/die on days 1–21, plus Dexametasone 40 mg/die on days 1, 8, 15, and 22. This BdL schedule was relatively tolerated and showed promising efficacy. Based on the mainly myelosuppressive properties, concomitant treatment with growth factors are recommended for all patients. The toxicity profile of BdL scheme resulted in an acceptable treatment-related toxicity and mortality and induced a good quality responses in a pretreated population of MM pts. Disclosures: No relevant conflicts of interest to declare.

Abstract: Background Elderly multiple myeloma (MM) patients are an heterogeneous population. Aging is associated with an increased frequency of co-morbidities, frailty and disability, with negative impact on treatment tolerance and outcome. A simple and reliable scoring system, based on geriatric assessment, has been developed to predict survival and used also to predict the risk of severe toxicities or treatment discontinuation in elderly newly diagnosed MM patients treated with lenalidomide-, bortezomib- or carfilzomib-based induction regimens. Methods Patients with newly diagnosed MM, ineligible for high-dose therapy and autologous stem cell transplantation due to age (≥65 years) or coexisting co-morbidities, enrolled in 3 prospective multicenter trials, were included in the analysis. Up-front dose reductions were performed according to patients age (full doses for patients ≤75 years and reduced for patients 〉 75 years). Details on treatment regimens and results of these studies have previously been reported (Gay F et al EHA 2013, Larocca A et al EHA 2013, Bringhen S et al EHA 2013). At diagnosis, a geriatric assessment had been performed, to assess co-morbidities, cognitive and physical conditions. Results 869 patients were included in the analysis: 659 enrolled in the lenalidomide-based, 152 in the bortezomib-based and 58 in the carfilzomib-based trial. Median age was 74 years, and 44% of patients were older than 75 years. Median follow-up was 18 months. In univariable analysis, the risk of death was higher in patients aged 75-80 (Hazard Ratio, HR 1.37, p=0.11), and in patients older than 80 years (HR 2.75, p 〈 0.001), compared to patients younger than 75 years. Performance status and gender did not significantly impact overall survival (OS). In a multivariable Cox model, an additive scoring system (range 0-5), based on age, co-morbidities, cognitive and physical conditions, was categorized to identify 3 groups: fit (score=0, 39%); unfit (score=1, 31%), and frail (score≥2, 30%). The 18-month OS was 92%, 88% and 73% in the three categories (fit, unfit and frail), respectively. In a Cox's model, including ISS, gender and performance status, the HR compared to the fit category was 1.4 (p=0.18) and 2.9 (p 〈 0.001) in unfit and frail patients. The cumulative 6-month risk of serious adverse events or treatment discontinuation was 44%, 47% and 55% in fit, unfit and frail patients, respectively. The higher mortality rate in unfit and frail patients seems mainly due to higher cumulative incidence of grade ≥3 adverse events (in particular extra hematologic toxicities) causing subsequent treatment discontinuation. Conclusions The use of a simple scoring system, based on geriatric assessment, allows the identification of groups of patients with different survival and risk of severe toxicities. Disclosures: Larocca: Celgene: Honoraria; Janssen-Cilag: Honoraria. Bringhen:Celgene: Honoraria; Janssen-Cilag: Honoraria; Novartis: Honoraria; Merck Sharpe & Dohme: Membership on an entity’s Board of Directors or advisory committees; Onyx: Consultancy. Gay:Celgene: Honoraria; Janssen-Cilag: Honoraria; Celgene: Membership on an entity’s Board of Directors or advisory committees; Byotest: Membership on an entity’s Board of Directors or advisory committees. Boccadoro:Celgene: Research Funding; Janssen-Cilag: Research Funding; Celgene: Consultancy; Janssen-Cilag: Consultancy; Celgene: Membership on an entity’s Board of Directors or advisory committees; Janssen-Cilag: Membership on an entity’s Board of Directors or advisory committees. Palumbo:Amgen: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Janssen Pharmaceuticals: Consultancy, Honoraria; Millenium: Consultancy, Honoraria; Onyx: Consultancy, Honoraria.

Abstract: Background: Chronic lymphocytic leukemia (CLL) is characterized by phenotypic and functional defects of immune cells, which often emerge into increased susceptibility to infections and autoimmunity, and also contribute to immune evasion of cancer cells. The BTK inhibitor ibrutinib exerts its anti-tumor activity via the targeting of key pathways in CLL cells. In addition, ibrutinib has also shown immune modulatory properties suggesting the ability to partially restore immune functions in CLL. Currently, available data are mainly limited to the activity exerted by ibrutinib on conventional T cells, whereas little is known on the effects induced on other non-neoplastic immune cell populations. Aim: The aim of this study was to perform a comprehensive and longitudinal analysis of the immune changes occurring in multiple lymphoid populations in a broad cohort of CLL patients treated with ibrutinib. Methods: We included 22 CLL patients with progressive disease (P-CLL) and eligible to ibrutinib therapy. Peripheral blood samples were collected from patients at baseline and after 1, 6 and 12 months of treatment with ibrutinib. For comparison, we also analyzed 7 healthy donors (HD) and 10 treatment-naïve CLL patients with stable disease not requiring treatment (S-CLL). The percentages and the absolute numbers of CLL cells, T cells, γδ (Vδ1 and Vγ9Vδ2) T cells, T regulatory cells (Tregs), natural killer (NK) and NK-T cells, as well as the expression of activation markers and immune checkpoint molecules were assessed by flow cytometry. The cytotoxic function of Vγ9Vδ2 T cells was evaluated using the CD107 assay. Statistical analyses were carried out by paired t-test. Results: Median age of enrolled patients was 70 years (range 42-80). The median lymphocyte count at study entry was 35.7 x 109/L (range 1.8-178) and the median number of previous treatment regimens was 2 (range 0-5). After 12 months of ibrutinib, 20 out of 22 (91%) patients achieved at least a partial response. The mean absolute number of CLL cells started to decrease by month 6 and became significantly lower than the baseline value by month 12. We also observed a parallel reduction of the total count of CD4+ T cells, CD8+ T cells and Tregs which reached statistical significance for the CD4+ T-cell compartment at the 12-month timepoint. Overall, ibrutinib treatment had no impact on the absolute numbers of Vδ1 and Vγ9Vδ2 T cells, NK and NK-T cells over time. In our cohort, we observed no change in the differentiation subset distribution of conventional CD4+ and CD8+ T cells, Tregs, Vδ1 and Vγ9Vδ2 T cells after 6 and 12 months of ibrutinib treatment. At baseline, we observed in the P-CLL cohort a significantly higher surface expression of the early activation marker CD69, both in the leukemic cell compartment and on T cells, NK and NK-T cells compared to S-CLL and HD. CD69 expression significantly decreased on CLL cells, T cells and NK-T cells already after 1 month of ibrutinib treatment, and on NK cells after 6 months (Figure 1A-D). The expression of the costimulatory molecule NKG2D was not modulated by ibrutinib treatment in any immune cell compartment. Among checkpoint molecules, the expression of CD96 was significantly reduced after 12 months of ibrutinib treatment on T lymphocytes and on NK, NK-T, and Vγ9Vδ2 T cells, whereas TIGIT, PD-1, TIM-3 and BTLA were not modulated (Figure 1E-H). In addition, when we restricted the analysis to patients showing a response in terms of lymphocyte count (i.e. 〉 50% reduction in 6 months) (11 out of 22 patients) we observed a recovery of CD16 surface expression on NK cells (Figure 1I, blue graph), a reduced expression of the co-inhibitory molecule TIGIT on Tregs (Figure 1J, blue graph) and a normalization in the mean values of CD4+ and CD8+ T cells, all becoming significant after 12 months of treatment. From a functional standpoint, we observed, after 12 months of treatment, an improvement in the cytotoxic function of Vγ9Vδ2 T cells in response to IL-2 and zoledronic acid, which was not associated to a modulation of their proliferative ability. Conclusions: Our data suggest that in CLL patients the anti-tumor activity of ibrutinib is paralleled by a dampening of immune exhaustion features, which is more evident in patients showing a more profound decrease in leukemic cell counts, and by a recovery of Vγ9Vδ2 T cell cytotoxic functions. These ibrutinib-induced effects might be exploited in the context of cellular immunotherapeutic strategies. Disclosures Mauro: Abbvie: Consultancy, Research Funding; Gilead: Consultancy, Research Funding; Shire: Consultancy, Research Funding; Jannsen: Consultancy, Research Funding; Roche: Consultancy, Research Funding. Scarfo:AstraZeneca: Honoraria; AbbVie: Honoraria; Janssen: Honoraria. Gaidano:Astra-Zeneca: Consultancy, Honoraria; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sunesys: Consultancy, Honoraria; AbbVie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Foà:Pfizer: 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; Celltrion: Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Speakers Bureau; Incyte: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Amgen Inc.: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Amgen Inc.: 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; Shire: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Abbvie: Consultancy, Speakers Bureau; Roche: Consultancy, Speakers Bureau; Roche: Consultancy, Speakers Bureau; Incyte: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celltrion: Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pfizer: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Shire: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Boccadoro:Amgen: Honoraria, Research Funding; Sanofi: Honoraria, Research Funding; Mundipharma: Research Funding; Celgene: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding; AbbVie: Honoraria. Coscia:Abbvie: Membership on an entity's Board of Directors or advisory committees; Karyopharm Therapeutics: Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding.

Abstract: Background: High-dose melphalan (HDM) is the standard therapy for autologous stem cell transplantation (ASCT) in multiple myeloma (MM), although the optimal conditioning regimen remains yet to be identified. Bendamustine (BENDA) has a proved activity in hematological malignancies including both first line and relapsed MM. Methods: We conducted a phase II trial, adding BENDA to HDM before second ASCT, in a tandem ASCT strategy, in 32 patients with "de-novo" MM. All patients received a bortezomib-based induction therapy. High-dose cyclophosphamide (CY) and G-CSF were used to mobilize stem cells. Four to 6 weeks after the administration of CY, patients received HDM (200 mg/mq), followed by ASCT. Three to 6 months after the first transplantation, patients received a second ASCT with BENDA (200 mg/m2) to HDM (140 mg/m2) as conditioning regimen (BM). Results: The median age was 56 years (range 40 to 66). Overall, there was no transplant related mortality. The incidence of neutropenic fever and mucositis (grade 1-2) was 46.9% and 81.2%, respectively. No mucositis grade 3-4 was observed. Median number of days to neutrophil and platelet engraftment were 11 and 12, respectively. After the second transplantation, the complete response (CR) improved to 62.5%. Overall response rate was 90.6%. After a median follow-up of 18,2 months, 4 patients had progressed and 1 died. Median progression free survival (PFS) was not reached and actuarial 2-year PFS and OS was 78% and 90%, respectively. Conclusion: Bendamustine plus melphalan is feasible as conditioning regimen for second ASCT in MM and should be explored for efficacy in a phase III study. Longer follow-up is needed to evaluate conversion rate and survival. Disclosures No relevant conflicts of interest to declare.

Abstract: Background: Proteasome inhibitor (PI)-based induction and consolidation proved to be effective in newly diagnosed multiple myeloma (NDMM) patients (pts) eligible for melphalan 200 mg/m2-autologous stem cell transplant (MEL200-ASCT). High response rates have been reported with the second-generation PI Carfilzomib in combination with Lenalidomide-dexamethasone (KRd) or Cyclophosphamide-dexamethasone (KCd). Aims: The primary aim was to evaluate the efficacy and safety of KRd induction-ASCT-KRd consolidation (KRd-ASCT-KRd) vs 12 cycles of KRd (KRd12) vs KCd induction-ASCT-KCd consolidation (KCd-ASCT-KCd). Methods: NDMM pts ≤65 years were randomized (1:1:1; stratification ISS and age) to: KRd-ASCT-KRd: 4 28-day cycles with KRd induction (Carfilzomib 20/36 mg/m2 IV days 1,2,8,9,15,16; Lenalidomide 25 mg days 1-21; dexamethasone 20 mg days 1,2,8,9,15,16) followed by MEL200-ASCT and 4 KRd consolidation cycles; KRd12: 12 KRd cycles; KCd-ASCT-KCd: 4 28-day induction cycles with KCd (Carfilzomib 20/36 mg/m2 IV days 1,2,8,9,15,16; Cyclophosphamide 300 mg/m2 days 1,8,15; dexamethasone 20 mg days 1,2,8,9,15,16) followed by MEL200-ASCT and 4 KCd consolidation cycles. Thereafter, pts were randomized to maintenance with Lenalidomide alone or plus Carfilzomib. Centralized minimal residual disease (MRD) evaluation - 8-color second generation flow cytometry, sensitivity 10-5 - was performed in pts achieving ≥very good partial response (VGPR). Endpoints were pre-maintenance stringent complete response (sCR) and MRD negativity in intention-to-treat (ITT) analysis. Data cut-off was May 30, 2018. Results: 474 NDMM pts were randomized (KRd-ASCT-KRd, n=158; KRd12, n=157; KCd-ASCT-KCd, n=159) and analyzed. Pts characteristics were well balanced. Median follow-up was 20 months. Depth of response improved during treatment (Figure). By ITT analysis, rates of pre-maintenance sCR was similar between KRd-ASCT-KRd (41%) and KRd12 (42%), and significantly higher than with KCd-ASCT-KCd (30%; P value KRd-ASCT-KRd vs KCd-ASCT-KCd=0.047; P value KRd12 vs KCd-ASCT-KCd=0.028). Similarly, rate of ≥CR was 49% with KRd-ASCT-KRd, 52% with KRd12 and 38% with KCd-ASCT-KCd (P value KRd-ASCT-KRd vs KCd-ASCT-KCd=0.041; P value KRd12 vs KCd-ASCT-KCd=0.014) and rate of ≥CR+unconfirmed CR (missing immunofixation confirmation) raised to 60% vs 63% vs 46% in the 3 groups, respectively; rate of ≥VGPR was 88% with KRd-ASCT-KRd, 86% with KRd12 and 74% with KCd-ASCT-KCd (P value KRd-ASCT-KRd vs KCd-ASCT-KCd=0.002; P value KRd12 vs KCd-ASCT-KCd=0.008). In multivariate analysis, the main factor affecting probability of achieving ≥VGPR, ≥CR or sCR was treatment with KRd-ASCT-KRd or KRd12 vs KCd, with no significant impact of ISS Stage or FISH abnormalities. In ITT analysis (MRD missing [31/395 VGPR pts, 8%] and 〈 VGPR were considered as MRD positive), MRD negativity was again similar with KRd-ASCT-KRd (58%) and KRd12 (54%) and significantly higher than with KCd-ASCT-KCd (41%; P value KRd-ASCT-KRd vs KCd-ASCT-KCd=0.004; P value KRd12 vs KCd-ASCT-KCd=0.023); 82% vs 78% vs 88% of pts in the 3 groups, respectively, could maintain extended MRD negative status with 2 MRD negative results obtained apart ≥6 months (either pre-ASCT and post consolidation or post consolidation and during maintenance). During treatment (excluding ASCT) the most frequent grade 3-4 AEs were neutropenia (KRd-ASCT-KRd 20%, KRd12 10%, KCd-ASCT-KCd 16%), thrombocytopenia (KRd-ASCT-KRd 15%, KRd12 8%, KCd-ASCT-KCd 13%) and infections (KRd-ASCT-KRd 14%, KRd12 12%, KCd-ASCT-KCd 13%). Grade 3-4 dermatologic AEs (KRd-ASCT-KRd, 5% with KRd12 12%, KCd-ASCT-KCd 1%), increase in liver enzymes (KRd-ASCT-KRd 9%, KRd12 10%, KCd-ASCT-KCd 1%) and hypertension (KRd-ASCT-KRd 3%, KRd12 8%, KCd-ASCT-KCd 3%) were more frequent with KRd12. Rates of grade 3-4 cardiac AEs (KRd-ASCT-KRd 3%, KRd12 2%, KCd-ASCT-KCd 4%) and thrombosis (KRd-ASCT-KRd 1%, KRd12 2%, KCd-ASCT-KCd 2%) were below 5% in all arms. Discontinuation for AEs was similar in the 3 arms (KRd-ASCT-KRd 6%, KRd12 8%, KCd-ASCT-KCd 7%). Conclusions: Rates of MRD negativity, sCR, ≥CR, ≥VGPR were significantly higher with KRd-ASCT-KRd and KRd12 vs KCd. At present, no differences in MRD and overall best response (sCR, ≥CR, ≥VGPR) were noticed between KRd-ASCT-KRd and KRd12; longer follow-up is needed to evaluate survival. Treatment was well tolerated. Updated data will be presented at the meeting. Figure. Figure. Disclosures Gay: Roche: Other: Advisory Board; Seattle Genetics: Other: Advisory Board; Bristol-Myers Squibb: Honoraria; Janssen: Honoraria; Celgene: Honoraria, Other: Advisory Board; Amgen: Honoraria; Takeda: Honoraria, Other: Advisory Board. Galli:Sigma-Tau: Honoraria; Janssen: Honoraria; Celgene: Honoraria; Bristol-Myers Squibb: Honoraria. Belotti:Celgene: Other: Advisory Board; Amgen: Other: Advisory Board. Zamagni:BMS: 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; Takeda: 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; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees. Angelucci:Novartis: Honoraria, Other: Chair Steering Committee TELESTO protocol in MDS; Celgene: Honoraria, Other: Chair DMC proptocol BELIEVE 1 and BELIVE 2 in Thalassemia; Vertex Pharmaceuticals Incorporated (MA) and CRISPR Therapeutics AG (CH): Other: Chair DMC CRISPR CAS9 in Hemoglobinopathies; Jazz Pharmaceuticals Italy: Other: Local (national) advisory board on AML; Roche Italia: Other: Local (national) advisory board on biosimilars. Annibali:Celgene; Takeda; Amgen, Janssen Cilag: Honoraria. Offidani:Amgen: Honoraria, Other: Advisory Board; Takeda: Honoraria, Other: Advisory Board; Janssen: Honoraria, Other: Advisory Board; Celgene: Honoraria, Other: Advisory Board; Bristol-Myers Squibb: Honoraria, Other: Advisory Board. Palumbo:Takeda: Employment. Musto:Amgen: Honoraria; BMS: Honoraria; Takeda: Honoraria; Janssen: Honoraria; Celgene: Honoraria. Cavo:GlaxoSmithKline: 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; Bristol-Myers Squibb: 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; Takeda: 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; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees. Boccadoro:Bristol-Myers Squibb: Honoraria, Research Funding; Mundipharma: Research Funding; Sanofi: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; AbbVie: Honoraria.