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Allogeneic hematopoietic stem cell transplantation (HSCT) represents the best therapeutic option for many patients with acute myeloid leukemia (AML). However, relapse remains the main cause of mortality after transplantation. The detection of measurable residual disease (MRD) by multiparameter flow cytometry (MFC) in AML, before and after HSCT, has been described as a powerful predictor of outcome. Nevertheless, multicenter and standardized studies are lacking. A retrospective analysis was performed, including 295 AML patients undergoing HSCT in 4 centers that worked according to recommendations from the Euroflow consortium. Among patients in complete remission (CR), MRD levels prior to transplantation significantly influenced outcomes, with overall (OS) and leukemia free survival (LFS) at 2 years of 76.7% and 67.6% for MRD-negative patients, 68.5% and 49.7% for MRD-low patients (MRD < 0.1), and 50.5% and 36.6% for MRD-high patients (MRD ≥ 0.1) (p < 0.001), respectively. MRD level did influence the outcome, irrespective of the conditioning regimen. In our patient cohort, positive MRD on day +100 after transplantation was associated with an extremely poor prognosis, with a cumulative incidence of relapse of 93.3%. In conclusion, our multicenter study confirms the prognostic value of MRD performed in accordance with standardized recommendations.

The value of measurable residual disease (MRD) in elderly patients with acute myeloid leukemia (AML) is inconsistent between those treated with intensive vs hypomethylating drugs, and unknown after semi-intensive therapy. We investigated the role of MRD in refining complete remission (CR) and treatment duration in the phase 3 FLUGAZA clinical trial, which randomized 283 elderly AML patients to induction and consolidation with fludarabine plus cytarabine (FLUGA) vs 5-azacitidine. After consolidation, patients continued treatment if MRD was =0.01% or stopped if MRD was

[Background]: Eltrombopag (EP) is a small molecule that acts directly on hematopoietic stem cells (HSCs) and megakaryocytes to stimulate the hematopoietic process. Mesenchymal stem/stromal cells (MSCs) are key hematopoietic niche regulators. [Objectives]: We aimed to determine whether EP has any effect on MSC function and properties (especially on their hematopoietic-supporting ability) and if so, what changes (e.g. genome-wide transcriptomic alterations) are induced in MSC after EP treatment. [Design/Methods]: MSCs were isolated from 12 healthy donors and treated with 15 µM and 50 µM of EP for 24 h. The toxicity of the drug on MSCs and their differentiation ability were analyzed, as well as the transcriptomic profile, reactive oxygen species (ROS) and DNA damage and the changes induced in the clonogenic capacity of HSCs., [Results]: The results show that EP also modifies MSC functions, decreasing their adipogenic differentiation, increasing the expression of genes involved in hypoxia and other pathways related to oxygen homeostasis, and enhancing their ability to support hematopoiesis in vitro., [Conclusion]: Our findings support the use of EP in cases where hematopoiesis is defective, despite its well-known direct effects on hematopoietic cells. Our findings suggest that further studies on the effects of EP on MSCs from patients with aplastic anemia are warranted., This study was supported by research funding from Novartis Pharmaceuticals to FS-G. SP is supported by Fundación Española de Hematología y Hemoterapia (FEHH). SM is supported by RETIC and RICORS programs of ISCIII European Regional Development Fund (RD16/0011/0015, RD21/0017/0006), ‘A way to make Europe’ and NextGenerationEU. GJMC and ESL are supported by the Spanish Ministerio de Ciencia e Innovación (FPU18/03533 and PFIS/19/00272 respectively).

This open-label, randomized, phase 3 trial (NCT02577406) compared enasidenib, an oral IDH2 inhibitor, with conventional care regimens (CCR) in patients aged =60 years with late-stage, mutant-IDH2 acute myeloid leukemia (AML) relapsed/refractory (R/R) to 2 or 3 prior AML-directed therapies. Patients were first preselected to a CCR (azacitidine, intermediate-dose cytarabine, low-dose cytarabine, or supportive care), and then randomized (1:1) to enasidenib 100 mg/day or CCR. The primary endpoint was overall survival (OS). Secondary endpoints included event-free survival (EFS), time to treatment failure (TTF), overall response rate (ORR), hematologic improvement (HI), and transfusion independence (TI). Overall, 319 patients were randomized to enasidenib (n=158) or CCR (n=161). Median age was 71 years. Median (range) enasidenib exposure was 142 days (3-1270) and CCR was 36 days (1-1166). One enasidenib (0.6%) and 20 CCR (12%) patients received no randomized treatment, and 30% and 43%, respectively, received subsequent AML-directed therapies during follow-up. Median OS with enasidenib vs CCR was 6.5 vs 6.2 months (HR [hazard ratio] 0.86; P=.23); 1-year survival was 37.5% vs 26.1%. Enasidenib meaningfully improved EFS (median 4.9 months, vs 2.6 months with CCR; HR 0.68; P=.008), TTF (median 4.9 vs 1.9 months, HR 0.53; P

Simple Summary The use of venetoclax combined with hypomethylating agents or low-dose cytarabine in patients with newly diagnosed acute myeloid leukemia unfit for intensive chemotherapy was recently approved. However, the evidence in relapse or refractory patients is still scarce. The cohort of patients included in our study was heavily pretreated and had a poor performance status. It is still necessary to identify those patients at higher risk of early death who would not benefit from this type of treatment. For these ultra-high-risk patients, other treatment strategies should be followed. The effectiveness of venetoclax (VEN) in relapsed or refractory acute myeloid leukemia (RR-AML) has not been well established. This retrospective, multicenter, observational database studied the effectiveness of VEN in a cohort of 51 RR-AML patients and evaluated for predictors of response and overall survival (OS). The median age was 68 years, most were at high risk, 61% received >= 2 therapies for AML, 49% had received hypomethylating agents, and ECOG was >= 2 in 52%. Complete remission (CR) rate, including CR with incomplete hematological recovery (CRi), was 12.4%. Additionally, 10.4% experienced partial response (PR). The CR/CRi was higher in combination with azacitidine (AZA; 17.9%) than with decitabine (DEC; 6.7%) and low-dose cytarabine (LDAC; 0%). Mutated NPM1 was associated with increased CR/CRi. Median OS was 104 days (95% CI: 56-151). For the combination with AZA, DEC, and LDAC, median OS was 120 days, 104 days, and 69 days, respectively; p = 0.875. Treatment response and ECOG 0 influenced OS in a multivariate model. A total of 28% of patients required interruption of VEN because of toxicity. Our real-life series describes a marginal probability of CR/CRi and poor OS after VEN-based salvage. Patients included had very poor-risk features and were heavily pretreated. The small percentage of responders did not reach the median OS.

Acute myeloid leukemia (AML) is an attractive entity for the development of chimeric antigen receptor (CAR) T-cell immunotherapy because AML blasts are susceptible to T-cell–mediated elimination. Here, we introduce sialic acid–binding immunoglobulin-like lectin 6 (Siglec-6) as a novel target for CAR T cells in AML. We designed a Siglec-6–specific CAR with a targeting domain derived from the human monoclonal antibody JML-1. We found that Siglec-6 is commonly expressed on AML cell lines and primary AML blasts, including the subpopulation of AML stem cells. Treatment with Siglec-6 CAR T cells confers specific antileukemia reactivity that correlates with Siglec-6 expression in preclinical models, including induction of complete remission in a xenograft AML model in immunodeficient mice (NSG/U937). In addition, we confirmed Siglec-6 expression on transformed B cells in chronic lymphocytic leukemia (CLL), and specific anti-CLL reactivity of Siglec-6 CAR T cells in vitro. Of particular interest, we found that Siglec-6 is not detectable on normal hematopoietic stem and progenitor cells (HSPCs) and that treatment with Siglec-6 CAR T cells does not affect their viability and lineage differentiation in colony-formation assays. These data suggest that Siglec-6 CAR T-cell therapy may be used to effectively treat AML without the need for subsequent allogeneic hematopoietic stem cell transplantation. In mature normal hematopoietic cells, we detected Siglec-6 in a proportion of memory (and naïve) B cells and basophilic granulocytes, suggesting the potential for limited on-target/off-tumor reactivity. The lack of expression of Siglec-6 on normal HSPCs is a key to differentiating it from other Siglec family members (eg, Siglec-3 [CD33]) and other CAR target antigens (eg, CD123) that are under investigation in AML, and it warrants the clinical investigation of Siglec-6 CAR T-cell therapy.

FLT3-ITD mutations are detected in approximately 25% of newly diagnosed adult acute myeloid leukemia (AML) patients and confer an adverse prognosis. The FLT3-ITD allelic ratio has clear prognostic value. Nevertheless, there are numerous manuscripts with contradictory results regarding the prognostic relevance of the length and insertion site (IS) of the FLT3-ITD fragment. We aimed to assess the prognostic impact of these variables on the complete remission (CR) rates, overall survival (OS) and relapse-free survival (RFS) of AML patients with FLT3-ITDmutations. We studied the FLT3-ITD length of 362 adult AML patients included in the PETHEMA AML registry. We tried to validate the thresholds of ITD length previously published (i.e., 39 bp and 70 bp) in intensively treated AML patients (n = 161). We also analyzed the mutational profile of 118 FLT3-ITD AML patients with an NGS panel of 39 genes and correlated mutational status with the length and IS of ITD. The AUC of the ROC curve of the ITD length for OS prediction was 0.504, and no differences were found when applying any of the thresholds for OS, RFS or CR rate. Only four out of 106 patients had ITD IS in the TKD1 domain. Our results, alongside previous publications, confirm that FLT3-ITD length lacks prognostic value and clinical applicability.

Background: Evaluation of MRD is standard in patients with AML. However, the role of decentralized MRD assessment for risk stratification in AML remains largely unknown, and so it does which methodological aspects are critical to empower the evaluation of MRD with prognostic significance, particularly if using MFC. Aim: To evaluate the role of decentralized MRD assessment using MFC for risk stratification and putative treatment individualization of patients with AML. Methods: This study was performed on 1,076 AML patients in complete remission (CR) after 7+3 induction chemotherapy, in whom MRD was evaluated by MFC in local laboratories over a period of 20 years in the PETHEMA group. We conducted a survey of technical aspects of MFC based MRD testing in the laboratories of the 60 participating Hospitals, to determine the impact of methodological heterogeneity in the prognostic value of MFC. Results: We first investigated the most effective MRD cutoff to stratify patients' risk at first remission. Patients were segmented into progressively higher cutoffs, starting at 0.01% followed by 0.05%, 0.1%, 0.5% and 1%. Our results showed that 0.1% reached higher statistical significance to discriminate patients with different relapse-free survival (RFS, HR: 0.77; P = .001) and overall survival (OS, HR: 0.73; P = .001). In multivariate analyses together with patients' age, WBC, genetic risk and post-consolidation therapy, MRD status was selected as an independent prognostic factor for OS. To further define the utility of "real-world" MRD assessment using MFC in risk stratification of AML, recursive partitioning was performed using the prognostic and treatment related factors selected in the multivariate Cox model for OS. Of the four variables evaluated, hematopoietic stem cell transplantation (HSCT, regardless of autologous or allogeneic source) vs no transplant emerged as the best single discriminator for OS, followed by genetic risk, age and MRD status. There were two branching points defined by MRD status; the first in patients ≤60 years with intermediate genetic risk who were not transplanted and the second in patients with adverse genetics who were not transplanted, in whom Forty-nine of the 60 hospitals (82%) responded to the survey on questions regarding the measurement of MRD using MFC in the PETHEMA LMA 1999, 2007 and 2010 protocols, providing information corresponding to 966 of the 1,076 (90%) patients regarding the number of markers, preparation of samples, instruments, approach (ie, LAIP, DfN or LAIP+DfN), number of cells to define a cluster, etc. The survey revealed significant heterogeneity intra- and inter-protocols that reflected improvement in MFC assessment of MRD over time, in the absence of harmonization nor standardization at the national level. Accordingly, we investigated if the heterogeneity in methodological, interpretation and reporting aspects of MFC based MRD testing were hampering its ability to predict outcome independently of other patient and treatment related factors. Strikingly, our results showed that except for the denominator used to calculate MRD burden (ie, total nucleated cells vs leukocytes), lack of standardization in all other parameters had an impact on the ability of MFC to predict outcomes in AML (Figure). Namely, panels with ≤4 markers or ≤2 combinations failed to identify patients with significantly different RFS according to MRD status, and MFC-based MRD monitoring was prognostic only when >500,000 cells were measured. Only MRD assessment using patient-specific panels was predictive of outcome. Conclusions: We report here one of the largest studies investigating the role of MRD monitoring using MFC. Our results confirmed that detection of MRD identifies patients in CR/CRi with inferior survival, but uncovered that decentralized MRD testing lacks significance when compared to other baseline risk factors and in the context of risk-adapted post-consolidation strategies. Thus, while this study demonstrated that "real-world" decentralized assessment of MRD using MFC does provide prognostic information in AML patients at first remission, our results question its readiness for risk stratification towards clinical decisions outside trials, at least until adequate standardization of this technique is achieved. Figure Disclosures Paiva: SkylineDx: Consultancy; Takeda: Consultancy, Honoraria, Research Funding; Roche: Research Funding; Adaptive: Honoraria; Amgen: Honoraria; Janssen: Consultancy, Honoraria; Karyopharm: Consultancy, Honoraria; Kite: Consultancy; Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau; Sanofi: Consultancy, Honoraria, Research Funding. Alonso Dominguez:Celgene: Research Funding; Incyte: Research Funding; Pfizer: Research Funding. Martinez-Lopez:Janssen: Speakers Bureau; Altum: Membership on an entity's Board of Directors or advisory committees, Patents & Royalties; Hosea: Membership on an entity's Board of Directors or advisory committees, Patents & Royalties; Roche: Speakers Bureau; Amgen: Speakers Bureau; Takeda: Speakers Bureau; Vivia Biotech: Honoraria; Novartis: Research Funding; BMS: Research Funding, Speakers Bureau; Incyte: Research Funding, Speakers Bureau. Sossa:Astellas: Honoraria; Roche: Honoraria; Takeda: Honoraria; Novo: Honoraria. San-Miguel:Roche, AbbVie, GlaxoSmithKline, and Karyopharm: Consultancy, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb, Celgene, Novartis, Takeda, Amgen, MSD, Janssen, and Sanofi: Consultancy, Membership on an entity's Board of Directors or advisory committees.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection produces higher morbidity and mortality in hematological malignancies, but evidence in acute myeloid leukemia (AML) is scarce. A multicenter observational study was conducted to determine the clinical outcomes and assess the impact of therapeutic approaches in adult AML patients with SARS-CoV-2 infection in the first wave (March-May 2020). Overall, 108 patients were included: 51.9% with active leukemia and 70.4% under therapeutic schedules for AML. Signs and symptoms of SARS-CoV-2 were present in 96.3% of patients and 82.4% received specific treatment for SARS-CoV-2. The mortality rate was 43.5% and was correlated with age, gender, active leukemia, dyspnea, severe SARS-CoV-2, intensive care measures, neutrophil count, and D-dimer levels. A protective effect was found with azithromycin, lopinavir/ritonavir, and normal liver enzyme levels. During the SARS-CoV-2 first wave, our findings suggested an increased mortality in AML in a short period. SARS-CoV-2 management could be guided by risk factors in AML patients.

The role of decentralized assessment of measurable residual disease (MRD) for risk stratification in acute myeloid leukemia (AML) remains largely unknown, and so it does which methodological aspects are critical to empower the evaluation of MRD with prognostic significance, particularly if using multiparameter flow cytometry (MFC). We analyzed 1076 AML patients in first remission after induction chemotherapy, in whom MRD was evaluated by MFC in local laboratories of 60 Hospitals participating in the PETHEMA registry. We also conducted a survey on technical aspects of MRD testing to determine the impact of methodological heterogeneity in the prognostic value of MFC. Our results confirmed the recommended cutoff of 0.1% to discriminate patients with significantly different cumulative-incidence of relapse (-CIR- HR:0.71, P, This study was supported by the Centro de Investigación Biomédica en Red – Área de Oncología - del Instituto de Salud Carlos III (CIBERONC; CB16/12/00369, CB16/12/00233, CB16/12/00284 and CB16/12/00400), Instituto de Salud Carlos III/Subdirección General de Investigación Sanitaria (FIS No. PI16/01661, PI16/00517 and PI18/01946), Gerencia Regional de Salud de CyL (GRS 1346/A/16) and the Plan de Investigación de la Universidad de Navarra (PIUNA 2014-18). This study was supported internationally by the Cancer Research UK, FCAECC and AIRC under the Accelerator Award Program EDITOR.

PETHEMA/GEM Cooperative Group., Patients with multiple myeloma (MM) carrying standard- or high-risk cytogenetic abnormalities (CAs) achieve similar complete response (CR) rates, but the later have inferior progression-free survival (PFS). This questions the legitimacy of CR as a treatment endpoint and represents a biological conundrum regarding the nature of tumor reservoirs that persist after therapy in high-risk MM. We used next-generation flow (NGF) cytometry to evaluate measurable residual disease (MRD) in MM patients with standard- vs high-risk CAs (n = 300 and 90, respectively) enrolled in the PETHEMA/GEM2012MENOS65 trial, and to identify mechanisms that determine MRD resistance in both patient subgroups (n = 40). The 36-month PFS rates were higher than 90% in patients with standard- or high-risk CAs achieving undetectable MRD. Persistent MRD resulted in a median PFS of ∼3 and 2 years in patients with standard- and high-risk CAs, respectively. Further use of NGF to isolate MRD, followed by whole-exome sequencing of paired diagnostic and MRD tumor cells, revealed greater clonal selection in patients with standard-risk CAs, higher genomic instability with acquisition of new mutations in high-risk MM, and no unifying genetic event driving MRD resistance. Conversely, RNA sequencing of diagnostic and MRD tumor cells uncovered the selection of MRD clones with singular transcriptional programs and reactive oxygen species–mediated MRD resistance in high-risk MM. Our study supports undetectable MRD as a treatment endpoint for patients with MM who have high-risk CAs and proposes characterizing MRD clones to understand and overcome MRD resistance. This trial is registered at www.clinicaltrials.gov as #NCT01916252.

SARS-CoV-2 infection can impact survival of patients with acute myeloid leukemia (AML). International experts recommend considering delaying or stopping AML treatment, test patients who need intensive induction and s prioritizing outpatient treatment. However there is little published evidence in AML. Objective To analyze the clinical futures and outcome of SARS-CoV-2 infection in AML patients. Methods and patients Observational multicenter study between March and May 2020; 117 patients reported from 47 Spanish centers, but 13 had no PCR or antibody test documented, finally including 104 patients from 45 hospitals. Results The median age was 68 years, men (56.7% vs 43.3%), and the median time from AML diagnosis to SARS-CoV-2 was 4 months. The mean of comorbidities was 1.2, high blood pressure (40.4%), heart disease (17.3%), diabetes (13.5%), smoking (8.8%), chronic obstructive pulmonary disease or emphysema (7.7%), renal failure (6.7%) and liver dysfunction (1.9%). Cytogenetic risk was low in 16.9%, intermediate in 57.1% and high in 26.0%; 55.7% had active disease, 39.2% complete remission and 5.1% partial response. 29.4% were off-therapy and 70.6% under antileukemic treatment at the time of SARS-CoV-2: induction chemotherapy (25.3%), hypomethylating (19.3%), clinical trial (17.0%), consolidation chemotherapy (14.8%), venetoclax (3.4%), FLT3 inhibitors (3.4%) and/or maintenance (1.1%). Overall 3.7% were newly diagnosed (no prior therapy), 77.8% had received one line of treatment, 14.8% two and 3.7% four. 15.4% had prior allogeneic transplantation. Only 4.0% of the patients were asymptomatic, while the main signs and symptoms were fever (77.8%), pneumonia (75.0%), cough (65.3%), dyspnea (52.0%), diarrhea (20.4%), nausea and/or vomiting (12.2%), rhinorrhea (10.2%) and headache (7.4%). Analytical parameters were: neutrophils 3112 cells/µL (1900-7300), lymphocytes 1090 cells/µL (1000-3000), interleukin 6 118 pg/mL (0-100), ferritin 4505 ng/mL (15-150) and D-dimer 2823 ng/mL (20-500), with liver enzymes altered in 23.9% of cases. 84.2% received specific treatment for coronavirus infection: chloroquine or hydroxychloroquine (82.2%), lopinavir/ritonavir (54.0%), corticosteroids (39.6%), azithromycin (33.0%), tocilizumab (15.8%), plasma convalescent (3.0%), clinical trial medication (3.0%), remdesivir (2.0%) and/or anakinra (1.0%). The course was mild in 14.7% (no hospitalization), moderate in 32.0% and severe in 53.3%. The implementation of intensive measures was assessed in 48.2%(14.9% admitted to the ICU and the remaining 33.3% rejected). The mean time to negativization was 20.5 days, duration of symptoms 17.6 days and the hospital stay 11.1 days. In 48.1% of the cases treatment for AML was maintained, in 26.6% delayed and in 25.3% modified due to coronavirus disease.47.5% died, establishing an association between mortality and age over 60 years (58.3% vs 36.4%, p=0.043), ≥2 lines of treatment (72.7% vs 44.3%, p=0.020), active disease (62.5% vs 29.4%, p=0.002) and pneumonia (61.2% versus 22.7%, p=0.002). Overall 47.5% overcame the infection, and in 5.0% SARS-CoV-2 genetic material was still detected at the time of analysis. A non-significant lower mortality rate was observed among: previous transplantation (45.7% vs 64.3%, p=0.19), neutrophil >1900 cells/µL (41.1% vs 60.0%, p=0.09), lymphocyte >1000 cells/µL (42.9% vs 63.6%, p = 0.09) and hydroxychloroquine/chloroquine plus azithromycin (35.3% vs 60.0%, p=0.10). Conclusions SARS-CoV-2 infection produces high mortality among AML patients. Mortality was correlated with age, active disease and pneumonia. Disclosures Martinez-Lopez: Janssen-cilag: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: Consultancy, Research Funding; Novartis: Consultancy; Janssen: Consultancy, Honoraria; Incyte: Consultancy, Research Funding.

The University Hospital of Salamanca, in Spain, had its first COVID-19 case on March 1st and as of May 11th, we had 1,100 positive cases. Based on the vulnerability of patients with blood cancers, on March 9th, the Hematology Department developed a protocol, amended as the new information was available, to maintain the Hematology Unit as a “free COVID-19 island.” The protocol included symptom-based surveys and screening tests to patients, caregivers, and healthcare personnel to identify early potential positive cases and prevent its spread. Between March 9 and April 28, 32 asymptomatic patients and caregivers were tested and 68 rT-PCR diagnostic assays have been performed with two positive results. A 106 healthcare workers have been tested (208 rT-PCR) and seven of them were positive. In summary, the implementation of preemptive measures after the first case appeared allowed us to be able to provide treatment to our patients.

This article belongs to the Special Issue Personalized Medicine: Recent Progress in Cancer Therapy., The biology and clinical impact of bone marrow (BM) infiltration in patients with diffuse large B-cell lymphoma (DLBCL) remains unclear in the rituximab era. We retrospectively analyzed 232 patients diagnosed with DLBCL at our center between 1999 and 2014. Concordant-presence of large cells similar to those of the lymph node biopsy- and discordant-infiltration by small cells forming lymphoid aggregates, lacking cytological atypia-BM infiltration was defined by histological criteria and further characterized by flow cytometry (FCM). Cell of origin (COO) was determined using Hans’ algorithm. For the clonal relationship between tumor and discordant BM, the VDJH rearrangement was analyzed. Survival analyses were restricted to 189 patients treated with rituximab and chemotherapy. Thirty-six (16%) had concordant, and 37 (16%) discordant BM infiltration. FCM described different indolent lymphomas among discordant cases, clonally related with DLBCL in 10/13 available samples. Median follow-up was 58 months. 5-year-progression-free survival (PFS) for non-infiltrated, discordant and concordant groups was 68%, 65% and 30%, respectively (p < 0.001). Combining COO and BM infiltration, patients with discordant BM and non-germinal center B-cell COO also had decreased 5-year-PFS (41.9%). In multivariate analysis, concordant BM had an independent effect on PFS (HR 2.5, p = 0.01). Five-year cumulative incidence of central nervous system (CNS) relapse was 21%, 4% and 1% in concordant, discordant and non-infiltrated groups, respectively (p < 0.001). In conclusion, concordant BM infiltration represents a subset with poor prognosis, whereas the prognostic impact of discordant BM infiltration could be limited to non-CGB cases., This work was partially supported by the Instituto de Salud Carlos III (ISCIII), Spanish Ministry of Economy and Competitiveness PI13/02644, PI15/01393, RD12/0036/0069, CIBERONC-CB16/12/00233, and “Una manera de hacer Europa” (Innocampus; CEI-2010-1-0010)”, the Health Council of the Junta de Castilla y León (GRS 850/A/13, GRS 1180/A/15, GRS 1350/A/16, GRS 1846/A/18, GRS 2035/A/19, and BIO/SA78/15), and Gilead Sciences (GLD17/00334). All Spanish funding is co-sponsored by the European Union FEDER program.

Background: Clonal evolution in AML originates long before diagnosis and is a highly dynamic process. Having a greater understanding of leukemogenesis may contribute to develop treatment strategies that target the tumor evolutionary process. However, dissecting leukemic transformation at the onset of AML is challenging without single-cell sequencing, and most clinical laboratories do not have infrastructure to perform these studies routinely. Patients with newly diagnosed AML may present dysplasia. If these residual, mature, dysplastic cells were generated before the differentiation blockage of blasts preceding leukemic transformation, it could be hypothesized that studying the genetic landscape of dysplastic cells and blasts could uncover the evolutionary process from dysplasia to AML. This hypothesis has never been investigated. Aim: Reconstruct clonal evolution from dysplasia to AML based on the genetic signature of dysplastic cells and leukemic blasts, analyzed using integrated MFC immunophenotyping and sorting with NGS. Methods: Presence of dysplasia according to aberrant phenotypic differentiation of the neutrophil, monocytic and erythroid lineages was investigated using MFC and EuroFlow MDS/AML panels in 283 newly diagnosed AML patients (median age 74; range 29-90). Patient-specific phenotypes were leveraged to isolate a total of 99 cell types from 22 AML cases for targeted (48 MDS/AML related genes) and whole-exome sequencing (WES), with a mean depth of 3246x and 141x, respectively. In patients with measurable residual disease (MRD) by MFC at the time of complete remission, tumor resistant cells were FACSorted for WES using patient-specific aberrant phenotypes. T cells were used as germline control in both approaches. Mutations were considered if ≥0.05 allele frequency in leukemic blasts or dysplastic cells and ≤0.2 in T cells. Results: We first assessed the applicability of our hypothesis by investigating how many patients show dysplasia at the onset of AML. Dysplastic cells were observed in 252 of 283 (89%) cases. Phenotypic abnormalities were more frequently noted in the neutrophil lineage (47%), followed by the monocytic (40%) and erythroid cells (13%). Up to 169/283 (60%) patients showed multi-lineage dysplasia. Only nine cases showed no signs of dysplasia, whereas the remaining 22 had undetectable hematopoiesis. Targeted sequencing of dysplastic cells and blasts in 16 patients uncovered three evolutionary patterns of leukemogenesis. Stable transition in those displaying identical mutational landscapes in blasts and residual mature dysplastic cells (9/16); clonal selection in cases where blasts originated from leukemic stem cells other than the ones driving dysplasia, due to mutations absent in blasts and present in dysplastic cells (4/16); and clonal evolution in cases showing new mutations in blasts onto mutations shared between these and dysplastic cells (3/16). Interestingly, most patients displaying stable transition from dysplasia to AML had mutated ASXL1, RUNX1 and/or TP53 (8/9). Mutations present in dysplastic cells while absent in blasts from patients showing a clonal selection evolutionary pattern, were more frequently detected in genes related to signaling pathways (eg JAK2, KRAS and NRAS). By contrast, clonal evolution was characterized by new mutations affecting FLT3ITD and STAG2. The higher throughput of WES of dysplastic cells and blasts from six patients unveiled a more complex dynamic process of leukemogenesis, with all three evolutionary patterns being detectable in nearly all cases. Most interestingly, we found patients with mutations in dysplastic cells and blasts at diagnosis, but not in MRD cells (eg NBPF1 and ZNF717); and patients showing mutations in dysplastic and MRD cells, but not in blasts at diagnosis (eg MUC2 and KIR2DL3). These findings uncover that genetic alterations that are critical in leukemic transformation and chemoresistance, may not overlap (Figure). Conclusions: We showed for the first time that it is possible to reconstruct leukemogenesis in nearly 90% of newly-diagnosed AML patients, using techniques that are commonly available in clinical laboratories. The possibility to identify the genetic drivers of leukemic transformation and chemoresistance, could be clinically meaningful to develop tailored treatment strategies aiming at the eradication of genetically diverse leukemic clones. Figure 1 Figure 1. Disclosures Prósper: Oryzon: Honoraria; Janssen: Honoraria; BMS-Celgene: Honoraria, Research Funding. Ayala: Incyte Corporation: Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Astellas: Honoraria; Celgene: Honoraria. Perez-Simon: JANSSEN, TAKEDA, PFIZER, JAZZ, BMS, AMGEN, GILEAD: Other: honorarium or budget for research projects and/or participation in advisory boards and / or learning activities and / or conferences. San-Miguel: AbbVie, Amgen, Bristol-Myers Squibb, Celgene, GlaxoSmithKline, Janssen, Karyopharm, Merck Sharpe & Dohme, Novartis, Regeneron, Roche, Sanofi, SecuraBio, and Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees. Montesinos: Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Pfizer: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Daiichi Sankyo: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Sanofi: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Incyte: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Karyopharm: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Stemline/Menarini: Consultancy; Teva: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Agios: Consultancy; Tolero Pharmaceutical: Consultancy; Forma Therapeutics: Consultancy; Glycomimetics: Consultancy; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Astellas Pharma, Inc.: Consultancy, Honoraria, Other: Advisory board, Research Funding, Speakers Bureau. Paiva: Celgene, EngMab, Roche, Sanofi, Takeda: Research Funding; Adaptive, Amgen, Bristol-Myers Squibb-Celgene, Janssen, Kite Pharma, Sanofi and Takeda: Honoraria; Bristol-Myers Squibb-Celgene, Janssen, and Sanofi: Consultancy.

Introduction: Acute myeloblastic leukaemia (AML) is an heterogeneous disease with different molecular and prognostic characteristics. According to the comorbidities and the revised 2017 European Leukaemia genetic risk stratification (ELN17), allogeneic hematopoietic cell transplantation (HCT) is the best therapeutic option for many patients with AML (Grimm, Blood Adv 2020). However, relapse remains the main cause of mortality after transplantation. Impact of MRD on the outcome of patients is well recognized and ELN2017 introduced the new response category complete remission (CR) without MRD (Döhner H, Blood 2017). Detection of measurable residual disease (MRD) by multiparameter flow cytometry (MFC) in AML before allogeneic HCT could be a powerful predictor of outcome and decisive when establishing strategies that modify the prognosis of these patients. Methods: Retrospective multicentre analysis of MRD by MFC of patients undergoing transplantation allogeneic in 4 centres during the period from 2012 to 2020. Both Leukaemia Associated Aberrant Immunophenotype (LAIP) and different from normal (DFN) approach were used to analyse the MRD. The MRD was carried out with 8-color panels based on Euroflow protocols. The samples were acquired in 8-color digital cytometers (FACSCanto II) calibrated and compensated according to Euroflow protocols. Results: 295 of 318 patients were evaluated. Table 1 shows the characteristics of the patients. 285 (96.7%) were in complete remission (CR), 207 had negative MRD, in 21 MRD was less than 0.1% (MRD-low) and in 57 greater than or equal to 0.1% (MRD-high). At 2 years, the overall survival (OS) and leukaemia-free survival (LFS) in the whole group were 69% (95% CI 63.18-74.18) and 58.4% (95% CI 52.4-63.9) respectively. In CR patients, MRD levels significantly influenced on outcomes, with OS and LFS of 76.7% and 67.6% for negative MRD, 68.5% and 49.7% MRD-low and 50 % and 36.6% in MRD-high, p Figure 1 Figure 1. Disclosures Caballero: Celgene: Consultancy. Belén Vidriales: Roche: Consultancy; Novartis: Speakers Bureau; Jazz: Consultancy, Speakers Bureau; Astellas: Consultancy, Speakers Bureau. Montesinos: Karyopharm: Membership on an entity's Board of Directors or advisory committees, Research Funding; Sanofi: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Stemline/Menarini: Consultancy; Tolero Pharmaceutical: Consultancy; Agios: Consultancy; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Incyte: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Forma Therapeutics: Consultancy; Glycomimetics: Consultancy; Teva: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Pfizer: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Daiichi Sankyo: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Astellas Pharma, Inc.: Consultancy, Honoraria, Other: Advisory board, Research Funding, Speakers Bureau. Perez-Simon: JANSSEN, TAKEDA, PFIZER, JAZZ, BMS, AMGEN, GILEAD: Other: honorarium or budget for research projects and/or participation in advisory boards and / or learning activities and / or conferences.

Introduction The prognosis of patients with relapsed or refractory acute myeloid leukemia (RR-AML) is very poor, and treatment options are very limited. The exciting results of venetoclax (VEN) in untreated AML have led to its off-label use in RR-AML. However, evidence in RR-AML is still scarce and the available data are mostly from retrospective and single-center studies. The aim of our study was to analyze the effectiveness of VEN use in patients with RR-AML reported to the PETHEMA AML epidemiological registry. Initial results were presented previously (Labrador J, et al. ASH 2020). Here, we report an updated analysis. Methods We conducted a retrospective, multicenter, observational study of a cohort of patients with AML-RR who were treated with venetoclax in the hospitals of the PETHEMA group. We evaluated efficacy, CR/CRi rate and overall survival (OS). We performed a descriptive analysis. Overall survival (OS) was calculated using the Kaplan-Meier method. Results Fifty-one patients were included, 33 men and 18 women, with a median age of 68 years (25-82). The main characteristics of the included patients are shown in Table 1. With a median follow-up of 167 days, 10/51 patients (19%) continued to receive VEN at the time of analyses. Patients received a median of 2 cycles (0-8). VEN was administered with azacitidine (AZA) in 59%, with decitabine (DEC) in 29% and with low-dose cytarabine (LDAC) in 12% of patients, respectively. The CR/CRi and partial response (PR) rates were 12.4% and 10.4%, respectively. The CR/RCi and overall response (ORR, CR/CRi+PR) was higher in patients receiving VEN+AZA (17.9% and 32.1%) than in those receiving DEC + VEN (6.7% and 13.3%) or LDAC + VEN (0%). The presence of NPM1 or CEBPA variants were the only two variables associated with increased CR/CRi with VEN in RR-AML. Median OS was 104 days (95% CI: 56 - 151) (Figure 1A), 120 days in combination with AZA, 104 days with DEC, and 69 days with LDAC; p=0.875. Treatment response (Figure 1B) and ECOG 0 were the only variables that influenced OS in a multivariate model adjusted for age and sex (Table 2). VEN-resistant patients who received subsequent salvage therapy had superior median OS (98 vs. 5 days, p=0.004).Twenty-eight percent of patients required discontinuation of VEN due to toxicity. Sixty-one percent of patients required admission, mainly due to infections (45%), 10% due to bleeding and other causes in 12%. One case of tumor lysis syndrome was described. Conclusions Our real-life series depicts a marginal probability of CR/CRi and poor OS after venetoclax-based salvage. Patients treated with this regimen had very poor-risk features, and were heavily pre-treated, which could explain in part the observed poor outcomes. Although follow-up is still short, the small proportion of responders did not reach the median OS. Further studies will help to identify those patients potentially benefiting from venetoclax-based salvage regimens. Figure 1 Figure 1. Disclosures Belén Vidriales: Roche: Consultancy; Novartis: Speakers Bureau; Astellas: Consultancy, Speakers Bureau; Jazz: Consultancy, Speakers Bureau. Pérez-Encinas: Janssen: Consultancy. Tormo: Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Jazz Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pfizer: 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; Astellas: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Montesinos: Pfizer: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Glycomimetics: Consultancy; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Karyopharm: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Incyte: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Daiichi Sankyo: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Forma Therapeutics: Consultancy; Sanofi: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Teva: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Stemline/Menarini: Consultancy; Tolero Pharmaceutical: Consultancy; Agios: Consultancy; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Astellas Pharma, Inc.: Consultancy, Honoraria, Other: Advisory board, Research Funding, Speakers Bureau. OffLabel Disclosure: Venetoclax for Patients with Relapsed or Refractory Acute Myeloid Leukemia

Introduction The prognosis of patients with recurrent or refractory acute myeloid leukemia (AML-RR) is very poor, especially if they are not candidates for allogeneic transplantation (allo-SCT) after a second complete response (CR). Venetoclax, a potent and selective inhibitor of the antiapoptotic protein BCL-2, was approved by the FDA in combination with hypomethylating agents (HMAs) or low-dose cytarabine (LDAC) in patients with newly diagnosed AML of age ≥ 75 years, or who have comorbidities that preclude the use of intensive chemotherapy. However, the evidence in AML-RR patients is still scarce. For this reason, the objective of our study is to retrospectively analyze the efficacy of the off-label use of venetoclax in patients with AML-RR. Methods We conducted a retrospective, multicenter, observational study of a cohort of patients with AML-RR who were treated with venetoclax in the hospitals of the PETHEMA group. We evaluated efficacy, CR/CRi rate and overall survival (OS). We performed a descriptive analysis. Overall survival (OS) was calculated using the Kaplan-Meier method. Results A total of 41 patients were included, 25 men and 16 women, with a median age of 68 years (25 - 82 years) and an ECOG ≥ 2 at the beginning of the venetoclax treatment in 52% of the cases. Seventy-five percent of patients had AML with myelodysplasia-related changes. 25 patients (61%) were at high risk according to the European Leukemia Net 2017. Sixty-six percent of patients received ≥2 previous lines (range, 1-4), 29 patients (71%) received intensive first line chemotherapy, 10 (25%) received a previous transplant and 18 (44%) received previous treatment with HMA. Venetoclax median treatment duration was 40 days, and it was administered in 54% with azacitidine, 34% with decitabine and 12% with LDAC. In all, 11% of patients achieved CR/CRi. Only 10% of patients received subsequent salvage treatment. With a median follow-up time of 166 days (range, 21 - 311), 65% of the patients died. The median OS from diagnosis was 15 months (1 - 67 months) and the median from venetoclax initiation was 78 days (2 - 311 days). Those patients who achieved CR/CRi had higher OS (median not reached vs. 78 days, p= 0.048). Regarding toxicity, it was the expected in these patients. Twenty-eight percent of the patients required discontinuation of treatment due to toxicity. Sixty percent of the patients were admitted at some time during treatment with venetoclax, mainly because of infections (53%), 12% because of bleeding and other causes in 15%. Conclusions Our real-life series depicts a marginal probability of CR/CRi and poor OS after venetoclax-based salvage. Patients treated with this regimen had very poor-risk features, and were heavily pre-treated, which could explain in part the observed poor outcomes. Although follow-up is still short, the small proportion of responders did not reach the median overall survival. Further studies will help to identify those patients potentially benefiting from venetoclax-based salvage regimens. Disclosures Sanchez: Amgem: Other: travel grants; Janssen: Other: travel grants; Roche: Other: travel grants; Abbvie: Other: travel grants; Celgene: Other: travel grants. Tormo:Roche: Membership on an entity's Board of Directors or advisory committees; Astellas: Membership on an entity's Board of Directors or advisory committees; Servier: Honoraria; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria; MSD: Honoraria; Daiichi Sankyo: Honoraria. OffLabel Disclosure: The objective of our study is to retrospectively analyze the efficacy of the off-label use of venetoclax in patients with recurrent or refractory acute myeloid leukemia

[Purpose] Assessing measurable residual disease (MRD) has become standard with many tumors, but the clinical meaning of MRD in multiple myeloma (MM) remains uncertain, particularly when assessed by next-generation flow (NGF) cytometry. Thus, we aimed to determine the applicability and sensitivity of the flow MRD-negative criterion defined by the International Myeloma Working Group (IMWG)., [Patients and methods] In the PETHEMA/GEM2012MENOS65 trial, 458 patients with newly diagnosed MM had longitudinal assessment of MRD after six induction cycles with bortezomib, lenalidomide, and dexamethasone (VRD), autologous transplantation, and two consolidation courses with VRD. MRD was assessed in 1,100 bone marrow samples from 397 patients; the 61 patients without MRD data discontinued treatment during induction and were considered MRD positive for intent-to-treat analysis. The median limit of detection achieved by NGF was 2.9 × 10−6. Patients received maintenance (lenalidomide ± ixazomib) according to the companion PETHEMA/GEM2014MAIN trial., [Results] Overall, 205 (45%) of 458 patients had undetectable MRD after consolidation, and only 14 of them (7%) have experienced progression thus far; seven of these 14 displayed extraosseous plasmacytomas at diagnosis and/or relapse. Using time-dependent analysis, patients with undetectable MRD had an 82% reduction in the risk of progression or death (hazard ratio, 0.18; 95% CI, 0.11 to 0.30; P < .001) and an 88% reduction in the risk of death (hazard ratio, 0.12; 95% CI, 0.05 to 0.29; P < .001). Timing of undetectable MRD (after induction v intensification) had no impact on patient survival. Attaining undetectable MRD overcame poor prognostic features at diagnosis, including high-risk cytogenetics. By contrast, patients with Revised International Staging System III status and positive MRD had dismal progression-free and overall survivals (median, 14 and 17 months, respectively). Maintenance increased the rate of undetectable MRD by 17%., [Conclusions] The IMWG flow MRD-negative response criterion is highly applicable and sensitive to evaluate treatment efficacy in MM.

BACKGROUND: Older patients with acute myeloid leukaemia (AML) who are unsuitable for standard induction therapy have limited treatment options. While DNMT3A, TET2, IDH1/2 and TP53 mutations have been previously associated to better response to hypomethylating agents, there are no molecular biomarkers for low-dose cytarabine (LDAC)-based regimens. AIMS: To predict outcome in AML older patients at diagnosis based on mutation status in the context of FLUGAZA trial. FLUGAZA trial was focus on >65 years AML de novo patients comparing azacytidine vs. fludarabine and LDAC (FLUGA Scheme). METHODS: We analyzed bone marrow (BM) samples at diagnosis from 209 out of 285 AML patients treated according Flugaza trial (NCT02319135), azacytidine-arm (n=97) and FLUGA-arm (n=112). In this trial, patients were randomized to receive 3 induction cycles with fludarabine and cytarabine (FLUGA) followed by 6 consolidation cycles with reduced intensity FLUGA, vs 3 induction cycles with 5-azacytidine (AZA) followed by 6 consolidation cycles with AZA. Median age at diagnosis was 75 years (65-90). Both treatment groups were balanced for age, leucocytes count, baseline BM blasts, karyotype risk (ELN), and FLT3-internal tandem duplication and NPM1 gene mutations. Mutational profile analysis was carried out by NGS targeted gene sequencing (Ion Torrent S5XL System-Thermo Fisher Scientific) using a 43 genes custom panel implicated in leukemia prognosis. RESULTS: We detected 893 variants, 247 Indels and 646 SNVs. 206 (23.1%) of them were included as pathogenic or like-pathogenic by clinvar database. Ninety-five percent of patients (n=203) had at least one detectable mutation, and the median number of mutations was 4 (range = 0-8 mutations). The most common gene mutations were TET2 (N=55), FLT3 (n=52), SRSF2 (n=49), TP53 (n=45), DNMT3A (n=45), ASXL1 (n=45), RUNX1 (n=43), IDH2 (n=36), IDH1 (n=34), NPM1, (n=33) and NRAS (n=23). This mutational landscape is different to previous published in younger patients (Grimwade, Blood 2016), with higher number of patients with mutations in TP53 (21.5 vs 8%), SRSF2 (23.9 vs 2%), IDH1 (16.3 vs 7%) and IDH2 (17.2 vs 9%) and lower number of patients with mutation in NMP1 (15.8 vs 33%). The median OS of global series was 6 months (range 0-40). Multivariate Cox regression in the global series showed that NRAS and TP53 mutations predict reduced OS (Table 1). Distribution of mutations between both arms was not homogeneous (Figure 1) and NRAS (p=0.012) was more frequent among patients randomized to the FLUGA-arm. However, TP53 mutation frequency distribution was homogeneous: 23.7% in AZA-arm and 19.6% in FLUGA-arm (p=NS). In the AZA-arm, patient´s age was the only variable associated with not achieving composite complete remission (CR plus CR with incomplete recovery) and TET2 and EZH2 mutations were predictors to achieve composite CR. In the FLUGA-arm, TP53 and NRAS mutations were associated with not reaching composite CR (table 2). In the AZA-arm, cytogenetic was the only variable associated with risk of early death. In the FLUGA-arm, leucocyte count, TP53 and NRAS mutations were associated with risk of early death (table 3). In the AZA-arm, BCORL1 mutations (4.1%) were the only variable associated with high risk of relapse. In the FLUGA-arm, BCOR (7.1%) and TP53 (19.6%) mutations were associated with high risk of relapse (table 4). CONCLUSION The mutational profile of AML in elderly patients is different from the previously published in young patients. We have confirmed that a molecular pattern can identify patients with poor prognosis in elderly AML patients. NRAS and TP53 mutations confer a poor prognosis in LDAC (FLUGA-arm) patients, but this effect disappeared in the AZA-arm. BCOR and BCORL1 mutations were associated to a reduced DFS. These results confirm that azacytidine could be more efficacious than LDAC treatment for older patients with AML and mutations in TP53, NRAS, TET2 and EZH2. The percentage of patients who presented mutations in these genes amounted to 77% in this AML series. The study is registered at www.ClinicalTrials.gov as NCT02319135. This study was supported by the Subdirección General de Investigación Sanitaria (ISCIII, Spain) grants PI13/02387 and PI16/01530. Disclosures Salamero: Celgene: Honoraria; Novartis: Honoraria; Pfizer: Honoraria; Daichii Sankyo: Honoraria. Paiva:Amgen, Bristol-Myers Squibb, Celgene, Janssen, Merck, Novartis, Roche, and Sanofi; unrestricted grants from Celgene, EngMab, Sanofi, and Takeda; and consultancy for Celgene, Janssen, and Sanofi: Consultancy, Honoraria, Research Funding, Speakers Bureau. Fernandez:Pfizer: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Teva: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Abbvie: Membership on an entity's Board of Directors or advisory committees; Incyte: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Karyopharm: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Daiichi Sankyo: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau.

Early diagnosis and risk stratification are key to improve outcomes in light-chain (AL) amyloidosis. Here we used multidimensional-flow-cytometry (MFC) to characterize bone marrow (BM) plasma cells (PCs) from a series of 166 patients including newly-diagnosed AL amyloidosis (N = 94), MGUS (N = 20) and multiple myeloma (MM, N = 52) vs. healthy adults (N = 30). MFC detected clonality in virtually all AL amyloidosis (99%) patients. Furthermore, we developed an automated risk-stratification system based on BMPCs features, with independent prognostic impact on progression-free and overall survival of AL amyloidosis patients (hazard ratio: ≥ 2.9;P ≤.03). Simultaneous assessment of the clonal PCs immunophenotypic protein expression profile and the BM cellular composition, mapped AL amyloidosis in the crossroad between MGUS and MM; however, lack of homogenously-positive CD56 expression, reduction of B-cell precursors and a predominantly-clonal PC compartment in the absence of an MM-like tumor PC expansion, emerged as hallmarks of AL amyloidosis (ROC-AUC = 0.74;P, This study was supported by the Centro de Investigación Biomédica en Red – Área de Oncología—del Instituto de Salud Carlos III (CIBERONC; CB16/12/00369, CB16/12/00400 and CB16/12/00489), Instituto de Salud Carlos III/Subdirección General de Investigación Sanitaria (FIS No. PI13/02196), Asociación Española Contra el Cáncer (GCB120981SAN and Accelerator Award), the Black Swan Research Initiative of the International Myeloma Foundation, and the European Research Council (ERC) 2015 Starting Grant (MYELOMANEXT).

Background Although consensus guidelines have been proposed in 2010 for the diagnostic screening of paroxysmal nocturnal hemoglobinuria (PNH) by flow cytometry (FCM), so far no study has investigated the efficiency of such medical indications in multicentric vs. reference laboratory settings. Methods Here we evaluate the efficiency of consensus medical indications for PNH testing in 3,938 peripheral blood samples submitted to FCM testing in 24 laboratories in Spain and one reference center in Brazil. Results Overall, diagnostic screening based on consensus medical indications was highly efficient (14% of PNH+ samples) both in the multicenter setting in Spain (10%) and the reference laboratory in Brazil (16%). The highest frequency of PNH+ cases was observed among patients screened because of bone marrow (BM) failure syndrome (33%), particularly among those with aplastic anemia (AA; 45%) and to a less extent also a myelodysplastic syndrome (MDS; 10%). Among the other individuals studied, the most efficient medical indications for PNH screening included: hemolytic anemia (19%), hemoglobinuria (48%) and unexplained cytopenias (9%). In contrast, only a minor fraction of the patients who had been submitted for PNH testing because of unexplained thrombosis in the absence of cytopenia, were positive (0.4%). Conclusions In summary, our results demonstrate that the current medical indications for PNH screening by FCM are highly efficient, although improved screening algorithms are needed for patients presenting with thrombosis and normal blood cell counts. © 2016 International Clinical Cytometry Society

Severe hemorrhagic events occur in a significant fraction of acute promyelocytic leukemia patients, either at presentation and/or early after starting therapy, leading to treatment failure and early deaths. However, identification of independent predictors for high-risk of severe bleeding at diagnosis, remains a challenge. Here, we investigated the immunophenotype of bone marrow leukemic cells from 109 newly diagnosed acute promyelocytic leukemia patients, particularly focusing on the identification of basophil-related features, and their potential association with severe bleeding episodes and patient overall survival. From all phenotypes investigated on leukemic cells, expression of the CD203c and/or CD22 basophil-associated markers showed the strongest association with the occurrence and severity of bleeding (p ≤ 0.007); moreover, aberrant expression of CD7, coexpression of CD34+/CD7+ and lack of CD71 was also more frequently found among patients with (mild and severe) bleeding at baseline and/or after starting treatment (p ≤ 0.009). Multivariate analysis showed that CD203c expression (hazard ratio: 26.4; p = 0.003) and older age (hazard ratio: 5.4; p = 0.03) were the best independent predictors for cumulative incidence of severe bleeding after starting therapy. In addition, CD203c expression on leukemic cells (hazard ratio: 4.4; p = 0.01), low fibrinogen levels (hazard ratio: 8.8; p = 0.001), older age (hazard ratio: 9.0; p = 0.002), and high leukocyte count (hazard ratio: 5.6; p = 0.02) were the most informative independent predictors for overall survival. In summary, our results show that the presence of basophil-associated phenotypic characteristics on leukemic cells from acute promyelocytic leukemia patients at diagnosis is a powerful independent predictor for severe bleeding and overall survival, which might contribute in the future to (early) risk-adapted therapy decisions., This work was supported by the Fundación Científica de la Asociación Española Contra el Cáncer (AECC, Madrid, Spain) and the Fundación Rafael del Pino (Madrid, Spain) and both CIBERONC (CB16/12/00400, CB16/12/00233, CB16/12/00480) and grant PI16/00787 from Instituto de Salud Carlos III (Ministerio de Economía y Competitividad, Madrid, Spain).

In recent years, several studies on large series of multiple myeloma (MM) patients have demonstrated the clinical utility of flow cytometry monitoring of minimal residual disease (flow-MRD) in bone marrow (BM), for improved assessment of response to therapy and prognostication. However, disturbing levels of variability exist regarding the specific protocols and antibody panels used in individual laboratories. Overall, consensus exists about the utility of combined assessment of CD38 and CD138 for the identification of BM plasma cells (PC); in contrast, more heterogeneous lists of markers are used to further distinguish between normal/reactive PCs and myeloma PCs in the MRD settings. Among the later markers, CD19, CD45, CD27, and CD81, together with CD56, CD117, CD200, and CD307, have emerged as particularly informative; however, no single marker provides enough specificity for clear discrimination between clonal PCs and normal PCs. Accordingly, multivariate analyses of single PCs from large series of normal/reactive vs. myeloma BM samples have shown that combined assessment of CD138 and CD38, together with CD45, CD19, CD56, CD27, CD81, and CD117 would be ideally suited for MRD monitoring in virtually every MM patient. However, the specific antibody clones, fluorochrome conjugates and sources of the individual markers determines its optimal (vs. suboptimal or poor) performance in an eight-color staining. Assessment of clonality, via additional cytoplasmic immunoglobulin (CyIg) κ vs. CyIgλ evaluation, may contribute to further establish the normal/reactive vs. clonal nature of small suspicious PC populations at high sensitivity levels, provided that enough cells are evaluated.

Although information about the molecular pathogenesis of Waldenström macroglobulinemia (WM) has significantly advanced, the precise cell of origin and the mechanisms behind WM transformation from immunoglobulin-M (IgM) monoclonal gammopathy of undetermined significance (MGUS) remain undetermined. Here, we undertook an integrative phenotypic, molecular, and genomic approach to study clonal B cells from newly diagnosed patients with IgM MGUS (n = 22), smoldering (n = 16), and symptomatic WM (n = 11). Through principal component analysis of multidimensional flow cytometry data, we demonstrated highly overlapping phenotypic profiles for clonal B cells from IgM MGUS, smoldering, and symptomatic WM patients. Similarly, virtually no genes were significantly deregulated between fluorescence-activated cell sorter-sorted clonal B cells from the 3 disease groups. Interestingly, the transcriptome of the Waldenström B-cell clone was highly different than that of normal CD25-CD22+ B cells, whereas significantly less genes were differentially expressed and specific WM pathways normalized once the transcriptome of the Waldenström B-cell clone was compared with its normal phenotypic (CD25+CD22+low) B-cell counterpart. The frequency of specific copy number abnormalities [+4, del(6q23.3-6q25.3), +12, and +18q11-18q23] progressively increased from IgM MGUS and smoldering WM vs symptomatic WM (18% vs 20% and 73%, respectively; P = .008), suggesting a multistep transformation of clonal B cells that, albeit benign (ie, IgM MGUS and smoldering WM), already harbor the phenotypic and molecular signatures of the malignant Waldenström clone., This study was supported by Cooperative Research Thematic Network grants RD12/0036/0058 and RD12/0036/0048 of the Red de Cancer (Cancer Network of Excellence), Consejería de Sanidad, Junta de Castilla y Leon, Valladolid, Spain (557/A/10).

On behalf of the GEM (Grupo Español de Mieloma)/PETHEMA (Programa para el Estudio de la Terapéutica en Hemopatías Malignas) Cooperative Study Group., [Purpose]: To perform a critical analysis on the impact of depth of response in newly diagnosed multiple myeloma (MM). [Patients and Methods]: Data were analyzed from 609 patients who were enrolled in the GEM (Grupo Español de Mieloma) 2000 and GEM2005MENOS65 studies for transplant-eligible MM and the GEM2010MAS65 clinical trial for elderly patients with MM who had minimal residual disease (MRD) assessments 9 months after study enrollment. Median follow-up of the series was 71 months. [Results]: Achievement of complete remission (CR) in the absence of MRD negativity was not associated with prolonged progression-free survival (PFS) and overall survival (OS) compared with near-CR or partial response (median PFS, 27, 27, and 29 months, respectively; median OS, 59, 64, and 65 months, respectively). MRD-negative status was strongly associated with prolonged PFS (median, 63 months; P < .001) and OS (median not reached; P < .001) overall and in subgroups defined by prior transplantation, disease stage, and cytogenetics, with prognostic superiority of MRD negativity versus CR particularly evident in patients with high-risk cytogenetics. Accordingly, Harrell C statistics showed higher discrimination for both PFS and OS in Cox models that included MRD (as opposed to CR) for response assessment. Superior MRD-negative rates after different induction regimens anticipated prolonged PFS. Among 34 MRD-negative patients with MM and a phenotypic pattern of bone marrow involvement similar to monoclonal gammopathy of undetermined significance at diagnosis, the probability of >operational cure> was high; median PFS was 12 years, and the 10-year OS rate was 94%. [Conclusion]: Our results demonstrate that MRD-negative status surpasses the prognostic value of CR achievement for PFS and OS across the disease spectrum, regardless of the type of treatment or patient risk group. MRD negativity should be considered as one of the most relevant end points for transplant-eligible and elderly fit patients with MM., Supported by the Centro de Investigación Biomédica en Red – Area de Oncologia - del Instituto de Salud Carlos III (CIBERONC; CB16/12/00369; CB16/12/00400; CB16/12/00233; CB16/12/00284), formerly named as Cooperative Research Thematic Network (Grants No. RD12/0036/0058, RD12/0036/0048, RD12/0036/0046, and RD12/0036/0061) of the Red de Cancer (Cancer Network of Excellence); Instituto de Salud Carlos III/Subdirección General de Investigación Sanitaria; funded in part by the European Regional Development Fund (FIS No. 98/1239, 00/10160, 01/0089, 02/0089, 02/0905, G03/136, PI051284, PI06033906/1354, PS09/01897/01370, PI12/01761, PI12/02311, PI13/01469, PI14/01867, G03/136); Sara Borrell (No. CD13/00340); Asociación Española Contra el Cáncer (No. GCB120981SAN); and Federación Española de Enfermedades Raras. Also supported internationally by the Black Swan Research Initiative of the International Myeloma Foundation and the European Research Council 2015 Starting Grant (MYELOMANEXT).

Solitary plasmacytoma represents a heterogeneous group of patients; approximately half develop multiple myeloma (MM) in 2 or 3 years,whereas others remain disease-free at 10 years. By definition, these patients do not have morphologic bone marrow (BM) plasma cell (PC) infiltration. Here, we investigated whether sensitive BM evaluation of patients withsolitaryboneplasmacytoma(SBP; n = 35) andextramedullary plasmacytoma (EMP; n = 29) through multiparameter flow cytometry (MFC) would unravel the presence of clonal PCs in otherwise disease-free BM, and whether BMclonality predicted higher risk of progression. BMclonal PCs were detected in 17 of 35 SBP (49%) and 11 of 29 EMP (38%) patients. Seventy-one percent of flow-positive vs only 8% of flow-negative SBP patients evolved to MM (median time to progression of 26 months vs not reached; hazard ratio, 17.4; P < .001). No significant differences were observed among EMP cases. Our results highlight the importance of MFC for sensitive BM evaluation of SBP patients, to predict risk of developing treatment-requiring MM and to plan disease monitoring., This work was supported by the Cooperative Research Thematic Network grants RD12/0036/0058, RD12/0036/0069 and RD12/0036/0052 of the Red de Cancer (Cancer Network of Excellence), Instituto de Salud Carlos III, Spain, Instituto de Salud Carlos III/Subdirección General de Investigación Sanitaria (FIS: PI060339, 06/1354, 02/0905, 01/0089/01-02, PS09/01897/01370, G03/136, Sara Borrell: CD13/00340), Consejería de Educacion, Junta de Castilla y León Valladolid, Spain (HUS396A12-1), and Asociación Española Contra el Cáncer (AECC, GCB120981SAN), Spain.

Background: CC-90009 is a novel cereblon E3 ligase modulator (CELMoD), which is currently under investigation in a first-in-human, phase I study (CC-90009-AML-001; NCT02848001) in patients with R/R AML. In preclinical models, CC-90009 drives the binding of the target protein, translation termination factor G1 to S phase transition 1 (GSPT1), to cereblon and induces its ubiquitination and proteasome-dependent degradation. Loss of GSPT1 results in activation of the integrated stress response (ISR), inhibition of nonsense-mediated decay (NMD), and induction of apoptosis. Deep degradation of GSPT1, mediated by CC-90009, led to AML cell death in vitro and potent antitumor activity in patient-derived AML xenograft models. In the ongoing phase I study, CC-90009 has demonstrated antileukemic activity. Here, we characterize the pharmacodynamic responses using a suite of novel assays to support CC-90009 dose and schedule optimization. Methods: Adult patients with R/R AML received intravenous CC-90009 daily on Days 1-5 (D1-5 schedule) or on Days 1-3 and 8-10 (D1-3/8-10 schedule) of a 28-day cycle. Peripheral blood samples taken before, during, and after dosing in the first treatment cycle were analyzed. Levels of intracellular GSPT1 in blasts and normal blood cell types were quantitated by flow cytometry analysis. Transcript levels of ISR and NMD variants in peripheral blood mononuclear cells (PBMC) were measured by qPCR. Bone marrow (BM) core biopsies at screening, Cycle 1 Day 5 and 28, and Cycle 2 and 4 Day 28, were analyzed for GSPT1, cleaved caspase 3, and CD34 protein expression by immunohistochemistry. ATF3 and DDIT3 mRNA levels were assessed in BM samples by RNA in situ hybridization. Results: The rate and depth of GSPT1 loss in T cells and in circulating AML blasts increased with dose. A marked reduction in GSPT1 was observed in T cells and blast cells of most patients after the first dose of CC-90009 at all dose levels, and GSPT1 levels approached the assay floor between Days 2 and 5 at doses of 1.2 mg and higher on the D1-5 schedule. At 2.4 mg and higher on the D1-5 schedule, a reduction in GSPT1 levels of > 90% was observed in T cells (19 of 29 patients) and in blast cells (11 of 29 patients), with stronger GSPT1 reductions detected in AML blasts and normal T cells compared with B cells or granulocytes. In the 3 mg D1-5 cohort, patients with sustained GSPT1 reduction in peripheral blasts in the days following treatment had more persistent blast suppression compared with patients showing an earlier rebound of GSPT1. At 3 mg and 3.6 mg dose levels, continuous treatment (D1-5) resulted in slower kinetics of GSPT1 rebound and conferred superior antileukemic activity compared with the intermittent dosing schedule (D1-3/D8-10). In addition to measuring the direct target of CC-90009, GSPT1, we also investigated markers downstream of GSPT1 degradation. Several patients with deep and sustained GSPT1 loss in the high-dose cohorts (2.4 mg and above) showed increased levels of ISR-related transcripts (ATF3 and DDIT3) and NMD-associated splice variants (SRSF3 and SRSF6) in on-treatment PBMC samples. Similarly, in BM, deep GSPT1 loss coincided with induction of ATF3 and DDIT3 mRNA, increased cleaved caspase 3 expression, and reduced CD34+ blasts. These clinical findings are consistent with our preclinical studies in which GSPT1 loss culminated in apoptosis, which may be mediated through activation of ISR and inhibition of NMD pathways. Conclusions: CC-90009 is a novel CELMoD and a first-in-class GSPT1 degrader. A suite of novel pharmacodynamic assays performed on patient-derived peripheral blood cells and BM demonstrated a dose-dependent modulation of GSPT1, and showed that the preclinical mechanisms of ISR induction, NMD inhibition, and apoptosis can be confirmed in AML cells in patients. Deeper and more rapid GSPT1 degradation as well as delayed rebound were associated with more rapid, deeper, and more persistent blast reductions. Characterization of these pharmacodynamic responses in ongoing dose-schedule explorations will help identify the optimal scheme for the expansion phase and provide further insight into the mechanism of clinical response. Disclosures Fan: Celgene Corporation: Employment, Equity Ownership. Wang:Celgene Corporation: Employment. Couto:Celgene Corporation: Employment, Equity Ownership, Patents & Royalties. Yao:Celgene Corporation: Employment. Uy:Astellas: Consultancy; Pfizer: Consultancy; Curis: Consultancy; GlycoMimetics: Consultancy. Zeidan:Pfizer: Consultancy, Honoraria, Research Funding; Boehringer-Ingelheim: Consultancy, Honoraria, Research Funding; Trovagene: Consultancy, Honoraria, Research Funding; ADC Therapeutics: Research Funding; Jazz: Honoraria; Ariad: Honoraria; Agios: Honoraria; Novartis: Honoraria; Astellas: Honoraria; Daiichi Sankyo: Honoraria; Cardinal Health: Honoraria; Seattle Genetics: Honoraria; BeyondSpring: Honoraria; Otsuka: Consultancy, Honoraria, Research Funding; Abbvie: Consultancy, Honoraria, Research Funding; Acceleron Pharma: Consultancy, Honoraria, Research Funding; Medimmune/AstraZeneca: Research Funding; Celgene Corporation: Consultancy, Honoraria, Research Funding; Takeda: Consultancy, Honoraria, Research Funding; Incyte: Consultancy, Honoraria, Research Funding. Montesinos:Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Pfizer: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Karyopharm: Membership on an entity's Board of Directors or advisory committees, Research Funding; Teva: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Celgene Corporation: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Daiichi Sankyo: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Incyte: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Abbvie: Membership on an entity's Board of Directors or advisory committees. DeAngelo:Jazz Pharmaceuticals, Inc.: Consultancy; Takeda Pharmaceuticals: Consultancy; Shire: Consultancy; GlycoMimetics: Research Funding; Pfizer, Inc.: Consultancy; Novartis Pharmaceuticals Corporation: Consultancy, Research Funding; Incyte Corporation: Consultancy; Celgene Corporation: Consultancy; AbbVie, Inc.: Research Funding; Blue print Medicines: Consultancy, Research Funding; Amgen: Consultancy. Altman:Novartis: Consultancy; Cancer Expert Now: Consultancy; Biosight: Other: US Lead; Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Agios: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Daiichi Sankyo: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; France Foundation: Speakers Bureau; prIME Oncology: Speakers Bureau; PeerView: Speakers Bureau; Theradex: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Glycomimetics: Consultancy, Honoraria, Other: Data Safety and Monitoring Committee. Koprivnikar:Amgen: Speakers Bureau; Abbvie: Speakers Bureau; Pfizer: Honoraria; Novartis: Speakers Bureau. Vyas:Astellas: Speakers Bureau; Pfizer: Speakers Bureau; Abbvie: Speakers Bureau; Daiichi Sankyo: Speakers Bureau; Celgene: Research Funding, Speakers Bureau; Novartis: Research Funding, Speakers Bureau; Forty Seven, Inc.: Research Funding. Fløisand:Takeda: Membership on an entity's Board of Directors or advisory committees; Celgene Corporation: Honoraria; Novartis: Honoraria. Gjertsen:Astellas: Consultancy, Membership on an entity's Board of Directors or advisory committees; EU Horizon 2020: Research Funding; KinN Therapeutics AS: Equity Ownership; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; BerGenBio: Consultancy, Membership on an entity's Board of Directors or advisory committees; ERA PerMed: Research Funding; The Norwegian Cancer Society: Research Funding; Helse Vest Health Trust: Research Funding; Seattle Genetics: Consultancy, Membership on an entity's Board of Directors or advisory committees; Research Council of Norway: Research Funding; Daiichi Sankyo: Consultancy, Membership on an entity's Board of Directors or advisory committees; ACTII AS: Equity Ownership. Buchholz:Celgene Corporation: Employment, Equity Ownership. Pourdehnad:Celgene Corporation: Employment, Equity Ownership. Pierce:Celgene Corporation: Employment, Equity Ownership.

Background: CC-90009 is a cereblon (CRBN) E3 ligase modulator (CELMoD) and a first-in-class small molecule that drives the binding of a novel target protein, G1 to S phase transition 1 (GSPT1), to CRBN, resulting in the proteasome-dependent degradation of GSPT1. GSPT1 plays a central role in mRNA translation, and loss of GSPT1 activates an integrated stress response that leads to AML cell death (Matyskiela ME, et al. Nature. 2016;535:252-7; Zhouravleva G, et al. EBMO J. 1995;14:4065-72). In preclinical testing, CC-90009 is active across a range of AML cell lines and primary AML patient (pt) samples in vitro and in vivo and exerts its GSPT1- and CRBN-dependent effects through rapid induction of apoptosis. Here we share the first clinical results in pts with R/R AML. Methods: Adult pts with R/R AML enrolled in the dose-finding phase of this first-in-human, multicenter, open-label phase 1 study to evaluate tolerability, pharmacokinetics (PK), pharmacodynamics (PD), and preliminary efficacy of CC-90009; and to establish the recommended phase 2 dose and schedule (RP2D) (CC-90009-AML-001; NCT02848001). Dose escalation proceeded via a modified 3 + 3 design. Treatment was by daily intravenous administration on either Days 1-5 (D1-5) or Days 1-3 and 8-10 (D1-3/8-10) of a 28-day cycle. Treatment response was assessed after Cycles 1, 2, and 4 by modified International Working Group 2003 criteria. Safety and preliminary response data are presented for all treated pts. PK and PD were analyzed for evaluable pts. Results: As of May 15, 2019, 45 pts with R/R AML had been treated, including 35 pts on the D1-5 and 10 pts on the D1-3/D8-10 schedule. Median age was 66 years (range 27-81); 73% were male. Most pts (n = 36; 80%) were refractory to their last therapy and 17 pts (38%) were refractory to all prior therapy; 14 pts (31%) had secondary AML. Pts were treated at dose levels from 0.3 to 3.6 mg. Dose-limiting toxicities (DLTs) reported (only in dose levels from 2.4 to 3.6 mg) included hypotension, systemic inflammatory response syndrome (SIRS), hyperbilirubinemia, pneumonitis, and pericarditis with tamponade. Exploration of the 3.6 mg dose level is ongoing; the RP2D has not yet been determined. CC-90009-related grade 3/4 treatment-emergent adverse events (TEAEs) occurred in 23 pts (51%); those occurring in >1 pt were hypocalcemia (22%); hypotension (13%); and hyperbilirubinemia, hyperglycemia, hypophosphatemia, pneumonitis, sepsis, thrombocytopenia, and tumor lysis syndrome (4%). Preclinically identified hypocalcemia was confirmed as a CC-90009 on-target toxicity in the clinic; it was reversible, manageable and did not lead to any treatment discontinuations. The majority of treated pts experienced ≥1 serious TEAE (80%); most were infections (47%). Two (4%) pts experienced TEAEs leading to permanent discontinuation of the study drug. Dose interruptions due to TEAEs occurred in 12 pts (27%) and dose reductions in 2 pts (4%). Of 40 pts who discontinued treatment, 24 (60%) discontinued due to progressive disease or lack of efficacy. Seven pts discontinued treatment due to death; 4 deaths were secondary to progression from AML, 2 due to sepsis and 1 due to hyperglycemic hyperosmolar nonketotic syndrome. Responses to single-agent treatment were observed in pts treated at 3.0 or 3.6 mg on the D1-5 schedule, with a best response of complete remission (CR; n = 1), morphologic CR with incomplete blood count recovery (CRi; n = 1) and morphologic leukemia-free state (MLFS; n = 1). A dose-dependent decrease in GSPT1 levels in peripheral blood blasts and T cells was observed, with a >90% decrease observed for higher dose levels. Evidence of antileukemic activity (decreases in bone marrow and/or peripheral blasts) was seen in pts treated with CC-90009 at 1.2 mg and above with a trend to more sustained reductions at the highest dose levels. Plasma PK analysis demonstrated dose-dependent exposure. Conclusions: In this phase 1 study of CC-90009, a first-in-class agent, evidence of deep GSPT1 degradation, on-target activity and promising antileukemic activity was observed. The observed TEAEs, in addition to those expected in this heavily pretreated R/R AML pt population, were generally well manageable. The study is ongoing with further optimization of dose, schedule and toxicity mitigation. Expansion cohorts in R/R AML and higher-risk myelodysplastic syndromes are planned. Disclosures Uy: GlycoMimetics: Consultancy; Curis: Consultancy; Astellas: Consultancy; Pfizer: Consultancy. Montesinos:Daiichi Sankyo: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Incyte: 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, Research Funding, Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Celgene Corporation: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Abbvie: Membership on an entity's Board of Directors or advisory committees; Teva: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Karyopharm: Membership on an entity's Board of Directors or advisory committees, Research Funding. DeAngelo:Blue print Medicines: Consultancy, Research Funding; Celgene Corporation: Consultancy; Shire: Consultancy; Pfizer, Inc.: Consultancy; Novartis Pharmaceuticals Corporation: Consultancy, Research Funding; Incyte Corporation: Consultancy; Jazz Pharmaceuticals, Inc.: Consultancy; GlycoMimetics: Research Funding; AbbVie, Inc.: Research Funding; Takeda Pharmaceuticals: Consultancy; Amgen: Consultancy. Altman:Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Biosight: Other: US Lead; France Foundation: Speakers Bureau; PeerView: Speakers Bureau; Agios: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Glycomimetics: Consultancy, Honoraria, Other: Data Safety and Monitoring Committee; Cancer Expert Now: Consultancy; Theradex: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy; prIME Oncology: Speakers Bureau; Daiichi Sankyo: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Koprivnikar:Amgen: Speakers Bureau; Pfizer: Honoraria; Abbvie: Speakers Bureau; Novartis: Speakers Bureau. Vyas:Astellas: Speakers Bureau; Abbvie: Speakers Bureau; Celgene: Research Funding, Speakers Bureau; Forty Seven, Inc.: Research Funding; Daiichi Sankyo: Speakers Bureau; Pfizer: Speakers Bureau; Novartis: Research Funding, Speakers Bureau. Fløisand:Takeda: Membership on an entity's Board of Directors or advisory committees; Celgene Corporation: Honoraria; Novartis: Honoraria. Gjertsen:BerGenBio: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Consultancy, Membership on an entity's Board of Directors or advisory committees; EU Horizon 2020: Research Funding; Daiichi Sankyo: Consultancy, Membership on an entity's Board of Directors or advisory committees; Astellas: Consultancy, Membership on an entity's Board of Directors or advisory committees; The Norwegian Cancer Society: Research Funding; KinN Therapeutics AS: Equity Ownership; ACTII AS: Equity Ownership; ERA PerMed: Research Funding; Helse Vest Health Trust: Research Funding; Research Council of Norway: Research Funding. Esteve:Astellas: Consultancy, Speakers Bureau; Amgen: Consultancy; Novartis: Consultancy, Research Funding, Speakers Bureau; Celgene: Consultancy, Speakers Bureau; Daiichi Sankyo: Consultancy; Jazz Pharmaceuticals: Consultancy; Roche: Consultancy; Pfizer: Consultancy. Buchholz:Celgene Corporation: Employment, Equity Ownership. Couto:Celgene Corporation: Employment, Equity Ownership, Patents & Royalties. Fan:Celgene Corporation: Employment, Equity Ownership. Hanna:Celgene Corporation: Employment, Equity Ownership. Li:Celgene Corporation: Employment, Equity Ownership. Pierce:Celgene Corporation: Employment, Equity Ownership. Hege:Celgene Corporation: Employment, Equity Ownership, Patents & Royalties; Mersana Therapuetics: Membership on an entity's Board of Directors or advisory committees; Society for Immunotherapy of Cancer: Membership on an entity's Board of Directors or advisory committees; Arcus Biosciences: Membership on an entity's Board of Directors or advisory committees. Pourdehnad:Celgene Corporation: Employment, Equity Ownership. Zeidan:Pfizer: Consultancy, Honoraria, Research Funding; Medimmune/AstraZeneca: Research Funding; Boehringer-Ingelheim: Consultancy, Honoraria, Research Funding; Trovagene: Consultancy, Honoraria, Research Funding; Incyte: Consultancy, Honoraria, Research Funding; Takeda: Consultancy, Honoraria, Research Funding; ADC Therapeutics: Research Funding; Jazz: Honoraria; Ariad: Honoraria; Agios: Honoraria; Seattle Genetics: Honoraria; BeyondSpring: Honoraria; Cardinal Health: Honoraria; Daiichi Sankyo: Honoraria; Novartis: Honoraria; Otsuka: Consultancy, Honoraria, Research Funding; Abbvie: Consultancy, Honoraria, Research Funding; Acceleron Pharma: Consultancy, Honoraria, Research Funding; Celgene Corporation: Consultancy, Honoraria, Research Funding; Astellas: Honoraria.

BACKGROUND AND OBJECTIVES: Chemosensitization using plerixafor combined with FLAG-IDA (PLERIFLAG regimen) showed promising results (48% CR/CRi) in a phase 2 trial for primary refractory and early relapsed (duration of first CR Patients: Of the 540 patients in the data base we analysed 300 patients relapsed or resistant to induction therapy, which had all data available. 241 patients were treated with FLAG-IDA, 41 with FLAGO-Ida, and 42 with PLERIFLAG. Differences between treatment cohorts were tested using Fisher exact test. Treatment cohorts (PLERIFLAG vs FLAG-IDA vs FLAGO-IDA) were similar in Age (p=0.5), Sex (p=0.5), FLT3-ITD mutated (p=0.5), EPI/HOVON cytogenetics score (p=0.5) and previous myelodisplasia (p=0.2). The three cohorts differed in time to relapse (p=0.001), previous stem cell transplantation (0.001), HOVON score (p=0.03) and SALFLAGE score (0.001). RESULTS There were no differences in terms of CR+CRi between the three types of treatment adjusted by Hovon risk score (Pleriflag: 48%, FLAG-IDA: 50% or FLAGO-IDA: 58%; Chrochan Maentel-Haenszel test, p=0.466) or SALFLAGE score (Chrochan-Maentel-Haenszel test, p=0.23). More patients were allografted in the PLERIFLAG (61%) group even not achieving CR/Cri, as compared to FLAG-IDA (38%) or FLAGO-Ida (61% vs 38% vs. 18%, p=0.0001). To compare PLERIFLAG against the other two types of salvage treatment we performed a Propensity Score in a proportion 1:3. We adjust variables like age, previous allogeneic transplant, time to relapse (refractory, 12 months), karyotype using MRC, and FLT3-ITD status. Karyotype risk was considered by HOVON criteria (inv16, t(8;21) vs others), and SALFLAGE (inv 16, intermediate risk, and unfavourable risk by MRC risk plus t(8;21)). The propensity score analyses showed that Compared to FLAG-IDA, PLERIFLAG was associated to increased survival (median OS 10.56 months vs. 5.6, p=0.03), but not improved EFS (2.83 months vs 1.41 months, p=0.8). The benefit in OS but not in EFS could be explained in part by frequent use of Allo SCT in patients who had not achieve CR/CRi in the PLERIFLAG cohort. In conclusion, our historical control study show that PLERIFLAG regimen is an acceptable therapeutic option for first relapsed/refractory adult AML patients. Disclosures Esteve: Jazz Pharmaceuticals: Consultancy; Amgen: Consultancy; Pfizer: Consultancy; Novartis: Consultancy, Research Funding, Speakers Bureau; Celgene: Consultancy, Speakers Bureau; Daiichi Sankyo: Consultancy; Roche: Consultancy; Astellas: Consultancy, Speakers Bureau. Salamero:Novartis: Honoraria; Pfizer: Honoraria; Celgene: Honoraria; Daichii Sankyo: Honoraria. Perez Encinas:CELGENE: Consultancy; JANSSEN: Consultancy; GILEAD SCIENCES: Research Funding. Montesinos:Incyte: 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, Other: Research support, Speakers Bureau; Pfizer: Membership on an entity's Board of Directors or advisory committees, Other: Research support, Research Funding, Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees, Other: Research support, Research Funding, Speakers Bureau; Daiichi Sankyo: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Research support, Speakers Bureau; Abbvie: Membership on an entity's Board of Directors or advisory committees; Karyopharm: Membership on an entity's Board of Directors or advisory committees, Other: Research support; Novartis: Membership on an entity's Board of Directors or advisory committees, Other: Research support, Research Funding, Speakers Bureau; Teva: Membership on an entity's Board of Directors or advisory committees, Other: Research support, Research Funding, Speakers Bureau.

Introduction. Nucleophosmin gene mutation (NPM1mut) occurs in around 30% of acute myeloid leukemia (AML) patients, frequently linked with favourable prognosis in the absence of FLT3-ITDmut, which occurs in around 40% of NPM1mutAML. Therefore, more expeditious diagnostic approaches may contribute to early diagnosis and prognostic stratification of these patients. Herein, we investigated the association of immunophenotypic features of leukemic and monocytic cells with the presence of NPM1mut in AML. Methods. A total of 404 bone marrow (BM) samples from newly-diagnosed AML patients according to WHO 2017 classification were retrospectively studied by 8-color flow cytometry, including 225 AML with NPM1mut and 179 cases wild type gene (NPM1wt). Information on FLT3-ITD could be obtained from 397/404 cases. Thus, FLT3-ITDmut was present in 85/397 (21%), being concomitant with NPM1mutin 62/85 AML cases (73%). Logistic regression analysis was used to identify predictive phenotypes for the presence of NPM1mut. Results. Overall, blast cell with immunophenotypic features of monocytic differentiation (corresponding to FAB M4 and M5 AML subtypes) were observed among 135/225 (60%) and 69/179 (38.5%) AML patients with NPM1mutand NPM1wt, respectively (p Among AML with monocytic blast cell differentiation, altered monocytic phenotypes were more frequent among NPM1mut vs. NPM1wtcases (98% vs. 36%) (p Noteworthy, in AML cases without blast cell monocytic differentiation, remaining monocytic cells showed similar asynchronous phenotypic patterns, which were also more frequent among NPM1mut cases (78% vs. 23% of NPM1wtcases, respectively; p In addition, aberrant CD9 blast cell expression was found in a significant proportion of all AML cases studied (124/222, 56%). However, altered CD9 was more frequent on (either monocytic or immature/myeloid) blast cells from AML cases with NPM1mut (76% vs. 46% NPM1wtcases; p0.05). In turn, aberrant CD25 expression on blast cells was otherwise linked to FLT3-ITDmut (61% vs. 20% of FLT3-ITDwtcases; p In multivariate analysis, baseline detection of monocytic-lineage blast cells with asynchronous expression of CD300 prior CD14 -C-index= 0.954, odds ratio (OR), 78.8; 95% confidence interval (CI), 13.1-471; p Conclusions. Detection of specific aberrant immunophenotypic patterns among blast cells and/or remaining monocytic cells from AML patients is highly predictive for NPM1mut, which may contribute to early diagnosis and follow-up of these patients. Disclosures Díez-Campelo: Celgene Corporation: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding.

Circulating myeloma tumor cells (CTCs) as defined by the presence of peripheral blood (PB) clonal plasma cells (PCs) are a powerful prognostic marker in multiple myeloma (MM). However, the biological features of CTCs and their pathophysiological role in MM remains unexplored. Here, we investigate the phenotypic, cytogenetic, and functional characteristics as well as the circadian distribution of CTCs vs paired bone marrow (BM) clonal PCs from MM patients. Our results show that CTCs typically represent a unique subpopulation of all BM clonal PCs, characterized by downregulation (P < .05) of integrins (CD11a/CD11c/CD29/CD49d/CD49e), adhesion (CD33/CD56/CD117/CD138), and activation molecules (CD28/CD38/CD81). Fluorescence in situ hybridization analysis of fluorescence-activated cell sorter-sorted CTCs also unraveled different cytogenetic profiles vs paired BM clonal PCs. Moreover, CTCs were mostly quiescent and associated with higher clonogenic potential when cocultured with BM stromal cells. Most interestingly, CTCs showed a circadian distribution which fluctuates in a similar pattern to that of CD34(+) cells, and opposite to stromal cell-derived factor 1 plasma levels and corresponding surface expression of CXC chemokine receptor 4 on clonal PCs, suggesting that in MM, CTCs may egress to PB to colonize/metastasize other sites in the BM during the patients' resting period.

Purpose Bortezomib-thalidomide-dexamethasone (VTD) is an effective induction therapy in multiple myeloma (MM). This phase II, noncomparative study sought to determine whether addition of cyclophosphamide to this regimen (VTDC) could further increase efficacy without compromising safety. Patients and Methods Patients age 18 to 70 years with previously untreated, measurable MM, who were eligible for high-dose chemotherapy–autologous stem-cell transplantation (HDCT-ASCT), were randomly assigned to bortezomib 1.3 mg/m2, thalidomide 100 mg, and dexamethasone 40 mg, with (n = 49) or without (n = 49) cyclophosphamide 400 mg/m2 for four 21-day cycles, followed by HDCT-ASCT. The primary end point was postinduction combined rate of near-complete response (nCR) or better (including complete response [CR] with normalized serum κ:λ free light chain ratio, CR, and nCR). Results Postinduction, 51% (VTD) and 44% (VTDC) of patients achieved combined CR/nCR, with bone marrow–confirmed CR in 29% and 31%, overall response rates of 100% and 96%, respectively, and very good partial response or better rates of 69% per arm. Post–HDCT-ASCT, combined CR/nCR rates were 85% (VTD) and 77% (VTDC). In all, 35% (VTD) and 27% (VTDC) of patients were negative for minimal residual disease (MRD) during induction and postinduction. Three-year overall survival was 80% (both arms). Grade 3 to 4 adverse events (AEs) and serious AEs were observed in 47% and 22% (VTD) and 57% and 41% (VTDC) of patients, respectively. The primary health-related quality of life end point (European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire C30 [EORTC QLQ-C30] Global Health score) steadily increased with VTD during induction and reached a clinically relevant difference post-transplantation versus baseline. Conclusion Both VTD and VTDC are highly active induction regimens producing high combined CR/nCR and MRD-negative rates; however, VTDC was associated with increased toxicity and suggestion of transient decreases in Global Health score, without an increase in activity.

Prognostic factors in Hodgkin lymphoma (HL) still fail to accurately identify high-risk patients. Tumor microenvironment in HL is a current focus of research for risk definition but few studies have focused on infiltrating lymphocytes. Here, we analyzed the number of tumor infiltrating lymphocytes by flow cytometry in diagnostic biopsies from 96 HL homogeneously treated patients with ABVD with or without radiotherapy. Most lymph node cells were lymphocytes (90 ± 17), with a median T/B/NK distribution of 74%/26%/0.7%, and CD4 T-cell predominance. The amount of CD19 B cells, and NK cells did not show association with disease features. However, high numbers of CD8 and CD4 cells were associated with better and poorer outcomes, respectively. Patients with ≥15% cytotoxic CD8 cells among the total cell population had a longer 10-year freedom from treatment failure (FFTF) (93% vs. 73%, p=.04). In turn, cases with ≥75% of CD4 infiltrating cells showed a significantly decreased FFTF (73% vs. 96%, p=.021). Consequently, CD4/CD8 ratio ≥5 associated with a poorer 10-year FFTF (69.5% vs. 94%, p=.02). This deleterious effect was particularly prominent in advanced disease (n = 58, p=.01). In multivariate analysis, a CD4/CD8 ratio ≥5 was the only independent variable to predict for treatment failure (HR = 4.5, 95% confidence interval, 1.2–16.8). In conclusion, our study shows that high CD4 and low CD8 T-cells infiltrates of tumor specimens associate with poor prognosis in HL patients, and CD4/CD8 ratio might be potentially useful for tailoring therapy.

Immunoparesis or suppression of polyclonal immunoglobulins is a very common condition in newly diagnosed myeloma patients. However, the recovery of polyclonal immunoglobulins in the setting of immune reconstitution after autologous stem cell transplantation and its effect on outcome has not yet been explored. We conducted this study in a cohort of 295 patients who had undergone autologous transplantation. In order to explore the potential role of immunoglubulin recovery as a dynamic predictor of progression or survival after transplantation, conditional probabilities of progression-free survival and overall survival were estimated according to immunoglobulin recovery at different time points using a landmark approach. One year after transplant, when B-cell reconstitution is expected to be completed, among 169 patients alive and progression free, 88 patients (52%) showed immunoglobulin recovery and 81 (48%) did not. Interestingly, the group with immunoglobulin recovery had a significantly longer median progression-free survival than the group with persistent immunoparesis (median 60.4 vs. 27.9 months, respectively; Hazard Ratio: 0.45, 95%Confidence Interval: 0.31-0.66; P

Clonal plasma cell disorders (PCDs) encompass a heterogeneous group of distinct entities characterized in common by a clonal expansion and accumulation of plasma cells (PCs) in the bone marrow (BM) and/or other tissues, which is associated in the vast majority of cases with the presence of their product(s) (monoclonal immunoglobulin [Ig], M component) at detectable amounts in serum or urine (1). Although the so-called diseases of immunoglobulin deposits (e.g., primary light chain [AL] amyloidosis) and lymphoplasmacytic lymphoma (e.g., Waldenstrom macroglobulinemia) also belong to this heterogeneous group of disorders, its most representative diagnostic subtypes include monoclonal gammopathy of undetermined significance (MGUS), solitary plasmacytoma, multiple myeloma (MM), plasma cell leukemia (PCL), and several subvariants of these entities (1, 2) (Table 1). The last four diagnostic categories of PCD are the main focus of this chapter.

For PETHEMA Programa para el Estudio de la Terapéutica en Hemopatías Malignas Cooperative Study Group., The clinical utility of minimal residual disease (MRD) analysis in acute myeloid leukaemia (AML) is not yet defined. We analysed the prognostic impact of MRD level at complete remision after induction therapy using multiparameter flow cytometry in 306 non-APL AML patients. First, we validated the prognostic value of MRD-thresholds we have previously proposed (≥0.1%; ≥0.01-0.1%; and, This work was supported in part by Spanish grants from Fondo de Investigación Sanitaria-ISCIII (FIS 00/0023-03, PI12/02321), DGCYT (SAF 94- 0308, SAF2001-1687), Conserjería de Educación de Castilla y León (HUS416A12), and Red Temática de Investigación Cooperativa en Cáncer (RTICC-ISCIII) (RD12/0036/0069).

The incorporation of high-dose therapy/autologous stem cell transplantation (HDT/ASCT) and novel agents has significantly improved survival in patients with multiple myeloma (MM), but whether this improvement also benefits patients harboring poor prognostic features, such as nonhyperdiploid MM (NH-MM) and a high proliferation index, remains largely unknown. We analyzed the DNA content and proliferation index of bone marrow plasma cells (PCs) by multiparameter flow cytometry in 595 newly diagnosed transplant-eligible patients with MM included in two consecutive PETHEMA/GEM trials: GEM2000 [VBMCP/VBAD (vincristine, carmustine, melphalan, cyclophosphamide, prednisone/vincristine, bischloroethylnitrosourea, adriamycin, and dexamethasone) followed by HDT/ASCT; n = 319] and GEM2005

The clinical value of multiparameter flow cytometry (MFC) immunophenotyping in primary or light chain amyloidosis (AL) remains unknown. We studied 44 consecutive bone marrow samples from newly diagnosed patients with amyloidosis; 35 patients with AL and 9 with other forms of amyloidosis. Monoclonal plasma cells (PCs) were identifiable by MFC immunophenotyping in 34 of 35 (97%) patients with AL, whereas it was absent from all but 1 of the 9 (11%) patients with other forms of amyloidosis. Quantification of bone marrow plasma cells (BMPCs) by MFC immunophenotyping was a significant prognostic factor for overall survival (OS) (≤ 1% vs > 1% BMPC cutoff; 2-year OS rates of 90% vs 44%, P = .02). Moreover, detecting persistent normal PCs at diagnosis identifies a subgroup of patients withAL with prolonged OS (> 5% vs ≤ 5% normal PC within all BMPC cutoff, 2-year rates of 88% vs 37%, P = .01). MFC immunophenotyping could be clinically useful for the demonstration of PC clonality in AL and for the prognostication of patients with AL. © 2011 by The American Society of Hematology., This work was supported by the Cooperative Research Thematic Cancer Network (RTIC) grants RD06/0020/0006 and G03/136, MM Jevitt, SL firm, Instituto de Salud Carlos III/Subdirección General de Investigación Sanitaria (FIS) grants PI060339, 02/0905, 01/0089/01-02, PS09/01897, and Consejería de Sanidad, Junta de Castilla y León, Valladolid, Spain grant 557/A/10.

Letter to the editor.-- et al., This study was supported by the Cooperative Research Thematic Network grants RD12/0036/0058 of the Red de Cancer (Cancer Network of Excellence); Instituto de Salud Carlos III, Spain, Instituto de Salud Carlos III/Subdirección General de Investigación Sanitaria (FIS: PI060339; 06/1354; 02/0905; 01/0089/01-02; PS09/01897/01370; G03/136; Sara Borrell: CD13/00340); and Asociación Española Contra el Cáncer (GCB120981SAN), Spain. The study was also supported internationally by the International Myeloma Foundation Junior Grant Proposal and the Multiple Myeloma Research Foundation research fellow award.