ALBERT

Description: Background: Transplant-eligible MM patients are achieving unprecedented CR rates with frontline therapy. This urges the question about what other tests are informative upon a negative immunofixation (IFx-), as well as if patients with short duration CR continue having dismal survival with modern frontline plus salvage therapies and if so, how to predict risk of unsustained CR. Aim: To provide an optimal definition of unsustained CR and biomarkers to predict it in transplant-eligible MM patients treated with optimal therapy. Methods: A total of 262 patients enrolled in the PETHEMA/GEM2012MENOS65 trial and who were in CR after receiving six induction cycles of bortezomib, lenalidomide and dexamethasone (VRD), autologous transplant and two consolidation cycles of VRD, were included in this study. Afterwards, patients were enrolled in the PETHEMA/GEM2014MAIN trial. Median follow-up of the series was 38 months after consolidation (53 months since diagnosis). Serum free light-chains (sFLC) were measured in 252 cases. MRD was assessment with next-generation flow (NGF) in 257 patients (median limit of detection of 2.8x10-6). FISH was performed in CD138-enriched plasma cells (PCs) from 223 patients at diagnosis [high-risk was defined by the presence of t(4;14), t(14;16) and/or del(17p)]. To understand the relationship between duration of CR and outcome, patients were segmented into 6-monht increments (range, 0 - 48 months) in time since response assessment after consolidation and loss of CR. Results: We first investigated what other tests commonly performed upon the achievement of IFx- were informative, particularly those employed to define stringent CR. The median percentage of PCs by morphology, at the time of IFx-, was 1.7% (range 0-5). Only 4 patients out of 266 (1.5%) with a negative immunofixation had 〉5% BM PCs and therefore, were not classified as in CR. Almost one-fourth of patients in CR display an abnormal sFLC ratio (56/248, 23%), but their PFS was identical to that of cases with normal sFLC ratio (3 years-PFS rates of 70% vs 72%; P=.6). BM biopsies were not performed in this study to evaluate PC clonality by immunohistochemistry but we noted that in CR patients with persistent MRD, the median percentage of clonal and normal PCs among total PCs identified by NGF was of 3% and 97%, respectively. Thus, the median percentage of normal PCs is 24-fold greater than clonal PCs within the PC compartment, and therefore simple κ/λ ratios measured in ≥100 PCs are unable to detect such low-levels of residual disease. Indeed, persistent MRD was detectable by NGF in 73/252 (29%) CR patients at a median level of 0.03% (range 0.0002% - 0.59%), and resulted in significantly inferior PFS (3-year rates of 49% vs 83% in cases with persistent vs undetectable MRD, P 〈 .00001) and OS (3 years-PFS rates of 84% vs 95%; P=.001). Afterwards, we sought to identify the optimal landmark to define unsustained CR and to identify which biomarkers could identify patients at risk. A duration of CR of 20% PCs (HR: 2.8 [1.2 - 6.7], P =.020) at diagnosis together with persistent MRD (HR: 4.3 [1.9 - 9.6], P

Description: Background. The Revised International Staging system (R-ISS) is the standard risk stratification model used for newly diagnosed (ND) multiple myeloma (MM) (Palumbo et al. JCO 2015). R-ISS identifies 3 groups of patients (pts) with different PFS and OS. However, 60% of pts are considered as intermediate-risk (R-ISS II), possibly including pts with different risk of progression/death. Recently, 1q copy number alterations (CNAs), which were not included in the R-ISS, proved to be a poor prognostic factor in NDMM pts. The European Myeloma Network (EMN), under the umbrella of the HARMONY project, collected more than 7000 patient data from European clinical trials. The aim of this analysis is to revise the R-ISS risk stratification model, by analyzing the prognostic value of each single baseline risk feature, including 1q CNAs, to improve prognostication in NDMM pts. Methods. Data from 15 European clinical trials enrolling NDMM pts from 2005 to 2014 were collected through EMN and registered in HARMONY platform. HARMONY is a European public-private partnership focusing on hematologic malignancies with unmet medical needs, including MM. OMOP Common Data Model was used to harmonize data. All pts received an immunomodulatory agent (IMiD) and/or a proteasome inhibitor (PI) upfront. In a multivariate Cox regression analysis adjusted for age, sex and therapy, we evaluated the impact of each risk feature on overall survival (OS) and progression-free survival (PFS). The hazard of death conferred by the most significant variables was used to create an additive risk score. Results. 7077 NDMM pts were registered in the HARMONY platform and included in the analysis. Data were mature with a median follow-up of 75 months; median age was 62 years. The majority of pts were transplant-eligible (65%). 40% of the pts received IMiDs only, 15% PIs only, 46% both drug classes during their first-line treatment. In a multivariate Cox model, ISS (II vs I HR 1.55 p

Description: Introduction: Patients with relapsed and refractory multiple myeloma (RRMM) have limited treatment options and experience poor health-related quality of life (HRQoL). Ide-cel, a B-cell maturation antigen (BCMA)-directed chimeric antigen receptor (CAR) T cell therapy, has shown a favorable clinical benefit-risk profile in patients with RRMM in the phase 2, single-arm KarMMa trial (Munshi NC, et al. J Clin Oncol 2020;38:8503). The impact of ide-cel treatment on primary HRQoL domains of interest preselected as most relevant for the treatment and target population (Fatigue, Pain, Cognitive Functioning, Physical Functioning, and Global Health) has been recently described (Delforge M, et al. HemaSphere 2020;4:EP1000). The aim of this analysis was to report the impact of ide-cel treatment on secondary HRQoL domains of interest and health utility scores in patients with RRMM in the KarMMa trial. Methods: Patients enrolled in the KarMMa trial (NCT03361748) had ≥ 3 prior antimyeloma treatment regimens (including an immunomodulatory drug, a proteasome inhibitor, and an anti-CD38 antibody) and were refractory to their last regimen per International Myeloma Working Group criteria. After lymphodepletion, patients received ide-cel at target dose levels of 150, 300 and 450 × 106 CAR+ T cells. HRQoL was assessed by the European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life C30 (QLQ-C30) and Myeloma Module (MY20) questionnaires and the EuroQol 5 dimensions 5 levels (EQ-5D-5L) instrument at screening, baseline, on the day of ide-cel infusion, and throughout the follow-up period at Months 1-6, 9, 12, and 15 post-infusion. For each domain, clinically meaningful changes from baseline were predefined as recommended in the literature. Analyses were performed after the cutoff date, October 16, 2019, and included patients with ≥ 9+1 months of follow-up. Statistical significance was calculated using the 2-sided Wilcoxon signed-rank test (0.05 significance level). EQ-5D-5L utility indices were calculated using the UK value set as the reference country and compared with UK general population data. Results: Of 128/140 patients enrolled in the KarMMa trial who received ide-cel, 95% (EORTC QLQ-C30) and 94% (EORTC QLQ-MY20, EQ-5D-5L) had a baseline and ≥ 1 post-baseline HRQoL assessment and were evaluable for HRQoL. The compliance rate was ≥ 80% for most visits. For EORTC QLQ-C30, patients demonstrated a clinically meaningful improvement in most functioning and symptom subscale scores from baseline to Month 3 through 15, with statistical significance (p 〈 0.05) reached at various time points for different subscales throughout the follow-up period. For the Role Functioning, Emotional Functioning and Social Functioning subscales, 〉 40% of patients reported a clinically meaningful improvement from baseline, ~25% had deterioration and ~35% had no change from baseline from Month 2 onward (Figure shows Month 9 results). Stable status was most frequently observed (~60%) on the Nausea/Vomiting, Constipation, Diarrhea, Insomnia, Dyspnea and Appetite Loss, and Financial Difficulties subscales. For EORTC QLQ-MY20, the mean change from baseline on the Future Perspectives subscale demonstrated a clinically meaningful improvement from baseline at Month 2 through 15, with statistical significance (p 〈 0.05) reached at Month 5. Body Image subscale scores remained stable from baseline through Month 15. The greatest proportion of patients (〉 48%) experienced a clinically meaningful improvement from baseline on the Future Perspective subscale. Stable status was most frequently observed (〉 59%) for the Body Image subscale. Both EQ-5D-5L index (0.68 vs 0.86) and EQ visual analogue scale (EQ VAS) scores (68 vs 83) were lower for patients treated with ide-cel when compared with UK general population scores. The index and EQ-VAS mean scores became more comparable to the UK data over time, showing a clinically meaningful (although not statistically significant) improvement from baseline beginning at Month 2 (EQ-5D-5L) or 3 (EQ-VAS) through Month 15. In most patients, a clinically meaningful improvement from baseline was observed, increasing from ~43% to ~47% (EQ-5D-5L index score) and ~57% to ~68% (EQ-VAS). Conclusion: These results show that ide-cel treatment brings clinically meaningful quality-of-life benefits to triple-class-exposed patients with RRMM without compromising any HRQoL domains. Disclosures Shah: BMS, Janssen, Bluebird Bio, Sutro Biopharma, Teneobio, Poseida, Nektar: Research Funding; GSK, Amgen, Indapta Therapeutics, Sanofi, BMS, CareDx, Kite, Karyopharm: Consultancy. Delforge:Amgen: Honoraria; BMS: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Takeda: Honoraria. San-Miguel:Amgen, BMS, Celgene, Janssen, MSD, Novartis, Takeda, Sanofi, Roche, Abbvie, GlaxoSmithKline and Karyopharm: Consultancy, Membership on an entity's Board of Directors or advisory committees. Bertin:ICON plc: Current Employment. Tahir:ICON plc: Current Employment. Lewis:ICON plc: Current Employment. Wang:Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Braverman:Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Campbell:BMS: Current Employment, Current equity holder in publicly-traded company. Dhanda:BMS: Current Employment, Current equity holder in publicly-traded company. Munshi:Takeda: Consultancy; C4: Current equity holder in private company; Janssen: Consultancy; Adaptive: Consultancy; Legend: Consultancy; Amgen: Consultancy; AbbVie: Consultancy; Karyopharm: Consultancy; OncoPep: Consultancy, Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties; BMS: Consultancy.

Description: Introduction: Both anti-apoptosis and pro-survival mechanisms promote myeloma cell growth and proliferation, and B-cell lymphoma-2 (BCL-2) is over-expressed in a subset of myeloma patients (pts). Venetoclax (V; orally administered BCL-2 inhibitor) monotherapy has demonstrated efficacy in RRMM pts with t(11;14) translocation, who represent 15-20% of the pt population. Given that the MAPK pathway is frequently dysregulated in myeloma, with NRAS/KRAS/BRAF mutations in 〉50% of RRMM cases (Xu et al. Oncogenesis 2017; Kortum et al. Blood 2016), we postulated that the combination of cobimetinib (C; orally administered MEK inhibitor) and V would not only shift the apoptotic balance towards cell death, thereby maximizing the effectiveness of V, but also boost CD8+ T-cell antigen recognition and immune-mediated tumor cell death when combined with atezolizumab (A; intravenously administered PD-L1 inhibitor), collectively improving responses in RRMM pts. Here, we present biomarker data from a Phase Ib/II study that was designed to assess safety, efficacy, and pharmacokinetics of C alone, C+V, and C+V+A in RRMM pts (NCT03312530). Objective: Biomarker analyses were performed to identify potential predictors of response to the C+V combination. Methods: t(11;14) status was determined by fluorescence in situ hybridization (FISH), and NRAS/KRAS/BRAF mutation status was assessed using Ion AmpliSeqTM Cancer Hotspot Panel v2. Immune monitoring was performed in longitudinal peripheral blood samples using multidimensional flow cytometry. RNA sequencing (RNAseq) was performed using CD138+ sorted cells. Results: A total of 49 pts were enrolled and randomized 1:2:2 to receive either C alone (n=6), C+V (n=22), or C+V+A (n=21). Overall, 0/6 (0%) pts in the C arm, 6/22 (27%) pts in the C+V arm and 6/21 (29%) pts in the C+V+A arm achieved a response (1 complete response, 3 very good partial responses and 8 partial responses). In the C+V+A arm, only 3/17 pts studied showed the pharmacodynamic (PD) effects of A (increase in CD8+HLA-DR+Ki-67+ T cells), who also showed an increase in T cell exhaustion phenotype (CD8+PD1+TIGIT+TIM3+ T cells), in comparison with nearly all pts who showed PD effects when treated with A alone in an earlier Phase Ib study (Cho et al. EHA 2018). On-treatment decreases in T-cell counts in pts treated with C+V and C+V+A versus C alone suggest that the C+V combination could affect T-cell viability. These results could partially explain the limited efficacy of A. Downstream response analyses were performed in 37/43 pts with known t(11;14) and NRAS/KRAS/BRAF mutation status from pts in the C+V and C+V+A arms to identify the pt subsets most likely to respond to the C+V combination (Figure1). In total, 6/8 (77%) t(11;14) pts and 5/29 (15%) non-t(11;14) pts responded to the C+V combination, versus 40% (n=30) and 6% (n=36) of pts, respectively, who responded to V monotherapy (Kumar S et al. Blood 2017). Mutation screening showed that 5/7 (71%) pts with both t(11;14) and NRAS/KRAS/BRAF mutation were responders. To investigate the efficacy observed in non-t(11;14) pts, we studied the BCL2/BCL2L1 (BCL-XL) gene expression ratio. In 27/43 pts with known t(11;14) status, NRAS/KRAS/BRAF mutation status and BCL2/BCL2L1 ratio, we found that 4/14 (29%) non-t(11;14) pts with either NRAS/KRAS/BRAF mutation or high BCL2/BCL2L1 ratio (〉2.3) had a response (Figure1 and2), of which 2 responders were mutant and had low BCL2/BCL2L1 ratio, while all pts with wild-type NRAS/KRAS/BRAF genes and low BCL2/BCL2L1 ratio (n=7) were non-responders. Conclusions: The data presented, albeit from a small Phase Ib/II study with limited biomarker-evaluable pts, suggest that t(11;14) pts with MAPK pathway mutations demonstrated improved response to the C+V combination when compared with wild-type non-t(11;14) pts, suggesting that inhibition of the MAPK pathway could be contributing to the observed efficacy in these pts. In addition, selecting for non-t(11;14) pts with either NRAS/KRAS/BRAF mutation or high BCL2/BCL2L1 ratio, representing 〉52% of the pt population in this study (Figure3), could enrich for responders to the C+V combination. The inclusion of NRAS/KRAS/BRAF biomarkers may improve the response rate in the non-t(11:14) pt population and also increase the size of the pt population that could benefit from a V-based regimen. Further investigation is needed to understand the contribution of C to the observed clinical benefit. Disclosures Raval: F. Hoffmann-La Roche: Current Employment, Current equity holder in publicly-traded company. Hamidi:Genentech, Inc.: Current Employment, Current equity holder in publicly-traded company; University of Michigan: Ended employment in the past 24 months. Hwang:F. Hoffmann-La Roche: Current equity holder in publicly-traded company; Genentech, Inc.: Current Employment, Current equity holder in publicly-traded company. Green:F. Hoffmann-La Roche: Current Employment, Current equity holder in publicly-traded company; Genentech, Inc: Current Employment. Onishi:F. Hoffmann-La Roche: Current Employment, Current equity holder in publicly-traded company; Genentech, Inc.: Current Employment, Current equity holder in publicly-traded company. Rodriguez-Otero:Janssen, BMS, AbbVie, Sanofi, GSK, Oncopeptides, Kite, Amgen: Consultancy, Honoraria; Celgene-BMS: Consultancy, Honoraria; Mundipharma: Research Funding; Janssen, BMS: Other: Travel, accommodations, expenses; BMS, Janssen, Amgen: 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. Gallo:F. Hoffmann-La Roche: Current Employment, Current equity holder in publicly-traded company. Paiva:Kite: Consultancy; SkylineDx: Consultancy; Takeda: Consultancy, Honoraria, Research Funding; Roche: Research Funding; Adaptive: Honoraria; Amgen: Honoraria; Janssen: Consultancy, Honoraria; Karyopharm: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau; Sanofi: Consultancy, Honoraria, Research Funding. Schjesvold:Amgen, Celgene, Janssen, MSD, Novartis, Oncopeptides, Sanofi, Takeda: Consultancy; Amgen, Celgene, Janssen, MSD, Novartis, Oncopeptides, Sanofi, SkyliteDX, Takeda: Honoraria; Celgene, Amgen, Janssen, Oncopeptides: Research Funding.

Description: Background: Isatuximab (Isa), a CD38 monoclonal antibody, is approved in combination with pomalidomide (P) and dexamethasone (d) for treatment of adults with relapsed/refractory multiple myeloma (MM). Bortezomib (V), lenalidomide (R), and d (VRd), is currently standard of care in patients (pts) with newly diagnosed MM not eligible for autologous stem cell transplant (ASCT) (Durie Lancet 2017). This study aims to evaluate the efficacy and safety of the approved short-duration fixed-volume infusion of Isa, combined with VRd in pts with NDMM ineligible or with no immediate intent for ASCT. A weight-based volume infusion of Isa-VRd in the same study (Part A) was well tolerated and efficacious (Ocio Blood 2018). Methods: In Part B of this Phase 1b study (NCT02513186), Isa (10 mg/kg) is administered as a fixed-volume infusion of 250 mL (mL/h infusion rate vs mg/h) with standard doses of VRd. The primary endpoint is complete response rate of Isa-VRd. The purpose of this first analysis is to assess the feasibility and safety of the fixed-volume infusion, particularly in relationship to infusion reactions (IRs). Recommended premedications are: diphenhydramine 25-50 mg IV (or equivalent), dexamethasone 20 mg IV/PO, ranitidine 50 mg IV (or equivalent), acetaminophen 650-1000 mg PO, montelukast 10 mg PO (or equivalent). The use of montelukast is strongly recommended in Cycle 1, optional from Cycle 2 onward. Results: Of 46 pts enrolled and treated in Part B, 39 (84.8%) were receiving study treatment at data cut-off (June 15, 2020). Median pt age was 70.0 years (range 49-87), with 8 (17.4%) pts ³75 years old. 24 (52.2%) pts were male. 23 (50.0%) pts were International Staging System Stage 1, with 19 (41.3%) and 3 (6.5%) pts at Stages 2 and 3, respectively. Similarly, 23 (50%) pts had an ECOG performance status of 0, with 22 (47.8%) and 1 (2.2%) pt(s) having an ECOG status of 1 and 2, respectively. Eight (17.4%) pts had bone marrow plasma cells ≥50%. Three (6.5%) pts had a creatinine clearance

Description: Background: AML is the most common acute leukemia in adults and its prevalence significantly increases in the elderly. The 5-year survival rate for adults younger than 60 is around 40% and decreases to 10% in patients above this age. Even those patients who tolerate intensive induction chemotherapy and achieve complete remission (CR) have poor outcome. Detection of MRD in younger AML refines outcome prediction of patients in CR after intensive chemotherapy. However the value of MRD in elderly patients is inconsistent between those treated with intensive vs hypomethylating drugs, and unknown after semi-intensive therapy. Aim: Define the role of MRD assessment by multidimensional flow cytometry (MFC) for therapeutic decision making in elderly AML patients treated with semi-intensive chemotherapy vs hypomethylating agents (HMA). Methods: Two-hundred eighty-three elderly AML patients were included in the PETHEMA phase III FLUGAZA clinical trial and randomized to receive three induction cycles with fludarabine and cytarabine (FLUGA) followed by six consolidation cycles with reduced intensity FLUGA, or three induction cycles with 5-azacitidine (AZA) followed by 6 consolidation cycles with AZA. After consolidation, patients continued with the same treatment if MRD ≥0.01% or stopped if MRD

Description: Introduction: Daratumumab (DARA) is a human IgGκ monoclonal antibody targeting CD38 with a direct on-tumor and immunomodulatory mechanism of action, and has been approved across lines of therapy for the treatment of multiple myeloma. The addition of DARA to standard-of-care (SoC) regimens, lenalidomide and dexamethasone (D-Rd) and bortezomib, melphalan, and prednisone (D-VMP), in the phase 3 MAIA and ALCYONE clinical studies reduced the risk of disease progression or death by ≥44%, nearly doubled the rate of complete response (CR) or better, and induced a 〉3-fold increase in MRD-negativity rates (10-5 sensitivity threshold) vs SoC alone in pts with TIE NDMM. In both MAIA and ALCYONE, MRD negativity was associated with longer progression-free survival (PFS), irrespective of trial treatments. MRD negativity provides an index of deep clinical response and may be a more robust evaluation of disease control if sustained over time. Here, we evaluate MRD negativity, including sustained MRD negativity, in pts with TIE NDMM from MAIA and ALCYONE and its association with PFS with longer follow-up. Methods: Pts with NDMM ineligible for high-dose chemotherapy with stem cell transplantation due to age (≥65 years) or unacceptable coexisting conditions in MAIA and ALCYONE were randomized (1:1) to SoC ± DARA. Pts in MAIA received 28-day cycles of Rd (R: 25 mg PO on Days 1-21; d: 40 mg PO QW) ± DARA (16 mg/kg IV QW for Cycles 1-2, Q2W for Cycles 3-6, and Q4W thereafter). ALCYONE pts received up to nine 6-week cycles of VMP (V: 1.3 mg/m2 SC twice weekly during Weeks 1, 2, 4, and 5 of Cycle 1 and QW during Weeks 1, 2, 4, and 5 of Cycles 2-9; M: 9 mg/m2 PO on Days 1-4 of Cycles 1-9; and P: 60 mg/m2 PO on Days 1-4 of Cycles 1-9) ± DARA (16 mg/kg IV QW for Cycle 1, Q3W for Cycles 2-9, and Q4W for Cycles 10+). Study treatments continued until progressive disease or unacceptable toxicity. MRD was assessed in MAIA and ALCYONE in all pts who achieved a CR or stringent CR. For ≥CR pts, additional MRD assessments occurred at 12, 18, 24, and 30 months after the first dose in ALCYONE and at 12, 18, 24, 30, 36, 48, and 60 months in MAIA. MRD was assessed via next-generation sequencing using the clonoSEQ® assay (v.2.0; Adaptive Biotechnologies, Seattle, WA) at the 10-5 sensitivity threshold. Sustained MRD negativity was defined as the maintenance of MRD negativity confirmed ≥6 or ≥12 months apart with no MRD positive test in between and was evaluated in the intention-to-treat (ITT) population. Results: A total of 737 (D-Rd, n=368; Rd, n=369) pts in MAIA and 706 (D-VMP, n=350; VMP, n=356) pts in ALCYONE were randomized; median duration of follow-up was 36.4 months in MAIA and 40.1 months in ALCYONE. In both studies, DARA-based therapy improved MRD negativity vs SoC in the ITT population (D-Rd, 28.8% vs Rd, 9.2%, P

Description: Introduction: Daratumumab (DARA) is a CD38-targeting monoclonal antibody approved for the treatment of MM. The addition of DARA to standard-of-care (SOC) regimens in the phase 3 ALCYONE (D-VMP vs VMP) and MAIA (D-Rd vs Rd) studies demonstrated deep and durable responses and improved progression-free survival in transplant-ineligible NDMM patients (pts). DARA-based regimens have shown increased infection rates vs SOC in both ALCYONE (grade 3/4 infections, 22% vs 15%) and MAIA (36% vs 27%). Most common (〉10 pts) grade 3/4 infection(s) was pneumonia (D-VMP/VMP; 13%/4%) in ALCYONE and were pneumonia (D-Rd/Rd; 15%/9%), influenza (3%/2%), bronchitis (3%/1%), and sepsis, urinary tract and lower respiratory tract infections (3% each) in MAIA. Most common (〉10 pts) serious adverse infection(s) was pneumonia (D-VMP/VMP; 12%/3%) in ALCYONE and pneumonia (D-Rd/Rd; 14%/9%), influenza (4%/2%), bronchitis (4%/2%), and upper respiratory tract infection (3%/3%) in MAIA. Using pooled data from DARA-treated pts in ALCYONE and MAIA, we report results of an analysis to identify predictive markers of grade ≥3 or serious infections that occurred during the first 6 mo of treatment. Methods: ALCYONE pts received ≥nine 6-week cycles of VMP (V: 1.3 mg/m2 SC on Days 1, 4, 8, 11, 22, 25, 29, and 32 of Cycle 1 and Days 1, 8, 22, and 29 of Cycles 2-9; M: 9 mg/m2 orally, and P: 60 mg/m2 orally on Days 1-4 of Cycles 1-9)±DARA (16 mg/kg IV), QW during Cycle 1, Q3W Cycles 2-9, and Q4W thereafter as maintenance therapy until disease progression or unacceptable toxicity. MAIA pts received 28-day cycles of Rd (R: 25 mg PO once daily on Days 1-21; d: 40 mg PO on Days 1, 8, 15 and 22)±DARA (16 mg/kg IV) QW Cycles 1-2, Q2W Cycles 3-6, and Q4W weeks thereafter. This analysis pooled data for DARA-treated pts in ALCYONE (median follow-up, 40.1 mo) and MAIA (median follow-up, 36.4 mo). Pooled data were randomly split into training and validation data. A predictive model was developed for time to first occurrence of treatment-emergent grade ≥3 or serious infections during the first 6 mo of study treatment. To identify the set of predictors for the Cox proportional hazard multivariate model, each candidate predictor was first assessed in a univariate model. Parameters with a P value

Description: Background: The transformation from a normal to a cancer cell is driven by the multistep acquisition of genetic alterations. Recently, shared mutations between clonal B cells in MBL/CLL and CD34+ hematopoietic progenitor cells (HPC) have been identified. Similarly, a HPC origin of BRAFV600E mutations in hairy cell leukemia (HCL) has been uncovered, strengthening the notion that at least a fraction of somatic mutations may occur in CD34+ HPC before the malignant transformation of some B cell neoplasms. Since almost all WM patients have mutated MYD88L265P, it is worthy to investigate if this disease follows a similar pathogenic process than that of MBL/CLL or HCL. Aim: Define the cellular origin of WM by comparing the genetic landscape of WM cells to that of CD34+ HPC, B cell precursors and residual normal B cells. Methods: We used FACSorting to isolate 57 cell subsets from bone marrow (BM) aspirates of 10 WM patients: CD34+ HPC, B cell precursors, residual normal B cells (if detectable), WM B cells, plasma cells (PCs) and T cells (germline control). Whole-exome sequencing (WES, mean depth 79x) was performed with 10XGenomics Exome Solution for low DNA-input due to limited numbers of some cell types. Single-cell RNA and B-cell receptor sequencing (scRNA/BCRseq) was performed in total BM B cells and PCs (n=32,720) from 3 IgM MGUS and 2 WM patients. Accordingly, the clonotypic BCR detected in WM cells was unbiasedly investigated in all B cell maturation stages defined according to their molecular phenotype. In parallel, MYD88p.L252P (orthologous position of the human L265P mutation) transgenic mice were crossed with conditional Sca1Cre, Mb1Cre, and Cγ1Cre mice to selectively induce in vivo expression of MYD88 mutation in CD34+ HPC, B cell precursors and germinal center B cells, respectively. Upon immunization, mice from each cohort were necropsied at 5, 10 and 15 months. Results: All 10 WM patients showed MYD88L265P and 3 had mutated CXCR4. Notably, we found MYD88L265P in B cell precursors from 1/10 cases and in residual normal B cells from 4/10 patients, which were confirmed by ASO-PCR and ddPCR. Indeed, these more sensitive methods detected MYD88L265P in B cell precursors from 6/10 cases and in residual normal B cells from 6/10 patients. CXCR4 was simultaneously mutated in B cell precursors and WM B cells from one patient. Overall, CD34+ HPC, B-cell precursors and residual normal B cells shared a median of 2 (range, 0-45; mean VAF, 0.13), 3 (range, 1-44; mean VAF, 0.168), and 6 (range, 1-56; mean VAF, 0.29) somatic mutations with WM B cells; some being found all the way from CD34+ HPC to WM B cells and PCs. Interestingly, concordance between the mutational landscape of WM B cells and PCs was

Description: Background: Although great strides were made in the management of MM, our best chances to eradicate this malignancy may lie in preventing its progression.Most current models to predict risk of transformation in SMM are commonly established at diagnosis and not reevaluated over time, because some parameters such as tumor burden or genetic abnormalities require invasive bone marrow (BM) aspirates. It could be hypothesized that periodic monitoring of tumor biomarkers is needed to improve risk-stratification of SMM patients, and so would be new minimally-invasive methods that can replace those performed in BM samples. Such methods should also monitor immune profiles, to identify patients with stable tumor burden/genetics but at risk of progression due to lost immune surveillance. Aim: Determine the level of concordance between the tumor/immune landscape in BM vs peripheral blood (PB) of SMM patients, as well as to evaluate immune profiles together with circulating tumor cell (CTC) numbers and genetic alterations every 6 months in PB, as minimally-invasive methods for identification of SMM patients at risk of developing active MM. Methods: 300 patients are planned to be enrolled in the iMMunocell study that includes 24 sites across 8 European countries. PB samples are collected every 6 months during three years for next-generation flow (NGF) cytometry monitoring of CTCs and immune profiles. Additionally, CTCs and various immune cells are FACSorted to evaluate, every 6 months, their molecular profile in SMM patients with stable vs progressive disease. BM samples are taken at baseline and every 12 months according to patients' choice, in which the same methods described previously for PB are performed. An interim analysis was preplanned to the moment when 150 patients were enrolled. Results: A total of 170 SMM patients were enrolled and we report here data on the first 150. Thus far, 18/150 (12%) patients progressed to MM and according to 20/20/20 criteria, 1 had low, 7 intermediate and 10 had high risk SMM. Only 7/18 cases who progressed had 〉20% BM plasma cells (PC) by morphology. CTCs were detectable in 107/150 (71%) patients at baseline (median of 0.001% [0% - 0.42%] and 0.03 [0 - 21] CTCs/µL of PB). There was no correlation (or only modestly-significant) between the percentage of CTCs and BMPC by morphology (r=0.156, p=0.065) or flow cytometry (r=0.293, p=0.02). Median CTC counts were 0.02, 0.03 and 0.11 in SMM patients with low, intermediate and high risk disease according to 20/20/20 criteria, respectively (p=0.002). Median CTC numbers were significantly different between cases with stable vs progressive disease (0.02 vs 0.11, p=0.005). As compared to those with ≤1 CTC/µL of PB, patients with 〉1 CTC/uL showed significantly higher risk of transformation (8% vs 47%, p0.5 CTCs/uL. Data on the genetic landscape of CTCs analyzed every 6 months from baseline to disease progression will be shown at the meeting. Immune monitoring in patient-paired PB and BM samples at baseline (n=50) uncovered that 48 of 74 innate and adaptive immune cell types measured by multidimensional flow cytometry had similar distribution. Furthermore, we found significant differences in the distribution of three CD8 T cell subsets defined by differential expression of CD28, CD127, PD1, TIGIT, in PB of SMM patients with stable vs progressive disease. In patients with longitudinal PB samples from baseline until progression to active MM (n=7), there was a significant decrease in helper effector memory CXCR3+CCR4+ and cytotoxic CD127+TIGIT+PD1+ T cells, together with a significant increase in adaptive NK cells and Tγδ CD69+ T cells. Conclusions: This is the first study performing CTC and immune monitoring every 6 months in PB samples from patients with SMM. Our results show a significant correlation between CTC counts and stable vs progressive disease, and suggest that CTC kinetics could be complementary to the 20/20/20 criteria for real-time identification of individual SMM patients at risk of developing active MM. Beyond CTC numbers, this study is uncovering key immune cell types associated with disease progression. Disclosures Terpos: Amgen: Honoraria, Research Funding; Genesis: Honoraria, Other: travel expenses , Research Funding; Janssen: Honoraria, Other: travel expenses , Research Funding; Takeda: Honoraria, Other: travel expenses , Research Funding; Celgene: Honoraria; Medison: Honoraria. Raab:Amgen: Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees, Research Funding; Heidelberg Pharma: Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees; Celgene: 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; Bristol-Myers Squibb: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees. Ocio:Sanofi: Consultancy, Honoraria; Secura-Bio: Consultancy; Oncopeptides: Consultancy; Celgene: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Speakers Bureau; Amgen: Consultancy, Honoraria; MDS: Honoraria; GSK: Consultancy; Takeda: Honoraria; Asofarma: Honoraria. Martinez-Lopez:Novartis: Consultancy; Janssen-cilag: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: Consultancy, Research Funding; Incyte: Consultancy, Research Funding; Janssen: Consultancy, Honoraria. de la Rubia:Amgen: Consultancy, Other: Expert Testimony; Celgene: Consultancy, Other: Expert Testimony; Janssen: Consultancy, Other: Expert Testimony; Ablynx/Sanofi: Consultancy, Other: Expert Testimony. Hajek:Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharma MAR: Consultancy, Honoraria; BMS: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Roche: Consultancy, Honoraria, Research Funding; Oncopeptides: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding. Ludwig:Celgene: Speakers Bureau; Janssen: Other: Advisory Boards, Speakers Bureau; Bristol Myers: Other: Advisory Boards, Speakers Bureau; Sanofi: Other: Advisory Boards, Speakers Bureau; Amgen: Other: Advisory Boards, Research Funding, Speakers Bureau; Takeda: Research Funding; Seattle Genetics: Other: Advisory Boards. Goldschmidt:Dietmar-Hopp-Foundation: Other: Grants and/or provision of Investigational Medicinal Product:; Chugai: Honoraria, Other: Grants and/or provision of Investigational Medicinal Product:, Research Funding; Incyte: Research Funding; Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other, Research Funding; Molecular Partners: Research Funding; Johns Hopkins University: Other: Grants and/or provision of Investigational Medicinal Product; Mundipharma GmbH: Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Honoraria, Research Funding; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Grants and/or provision of Investigational Medicinal Product:, Research Funding; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Grants and/or provision of Investigational Medicinal Product:, Research Funding; University Hospital Heidelberg, Internal Medicine V and National Center for Tumor Diseases (NCT), Heidelberg, Germany: Current Employment; GlaxoSmithKline (GSK): Honoraria; Adaptive Biotechnology: Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Grants and/or provision of Investigational Medicinal Product, Research Funding; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Grants and/or provision of Investigational Medicinal Product:, Research Funding; Merck Sharp and Dohme (MSD): Research Funding. Roccaro:European Hematology Association: Research Funding; AstraZeneca: Research Funding; Transcan2-ERANET: Research Funding; Italian Association for Cancer Research (AIRC): Research Funding; Janssen: Other; Celgene: Other; Amgen: Other. San-Miguel:Amgen, BMS, Celgene, Janssen, MSD, Novartis, Takeda, Sanofi, Roche, Abbvie, GlaxoSmithKline and Karyopharm: Consultancy, Membership on an entity's Board of Directors or advisory committees. Paiva:SkylineDx: Consultancy; Takeda: Consultancy, Honoraria, Research Funding; Roche: Research Funding; Adaptive: Honoraria; Amgen: Honoraria; Janssen: Consultancy, Honoraria; Karyopharm: Consultancy, Honoraria; Kite: Consultancy; Sanofi: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau.