Abstract: Abstract 351 Introduction A phase III study of melphalan (200 mg/m2)-based double autologous stem-cell transplantation (ASCT) incorporating thalidomide (T) and dexamethasone (D) with or without the addition of bortezomib (V) as first-line therapy for younger (≤65 years) patients (pts) with newly diagnosed multiple myeloma (MM) is currently being conducted by the Italian Myeloma Network GIMEMA. Patients and Methods By study design, pts were random assigned to receive three 21-d cycles of either bortezomib-thalidomide-dexamethasone (VTD) (V, 1.3 mg/m2 twice-weekly; T, 200 mg/d through d 1 to 63; D, 320 mg/cycle) or thalidomide-dexamethasone (TD) (both drugs at the same dose and schedule than in VTD) as induction therapy in preparation for ASCTs. Two 35-d cycles of either VTD or TD were given as consolidation therapy following ASCTs (V, 1.3 mg/m2 once-weekly; T, 100 mg/d through d 1 to 70; D, 320 mg/cycle). Primary study end point was the rate of high-quality responses [immunofixation negative complete response (CR) and ≥very good partial response (VGPR)] to induction therapy. Secondary study end points included response to, and toxicity of, subsequent treatment phases (including first and second ASCTs, and consolidation therapy), progression-free survival (PFS) and overall survival (OS). Analyses were intent to treat. All the 474 pts were evaluated for response to, and toxicity of, induction therapy. Responses reported by study investigators were centrally reassessed to confirm CR and VGPR; pts reported as complete responders but in whom bone marrow aspirate was not evaluable or not performed were reassessed as in VGPR. The VGPR category included the subcategories of near CR and VGPR. Results The study was closed to pts accrual after a total of 480 pts were enrolled; of these, 6 failed inclusion criteria and the remaining 474 were randomized to the VTD (n=236) or TD (n=238) arm. The mean total dose of V received in induction therapy was 14.7 mg (or 94% of that planned). Grade 3 peripheral neuropathy (PN) and skin rash (SR) were reported more frequently with VTD induction therapy than with TD (PN: 9.7% vs 2.1%, respectively; P 〈 0.001) (SR: 10% vs 1.7%, respectively; P 〈 0.001). In the VTD arm, resolution or reduction to at least grade 2 of PN was observed within a median of 26 days. Remarkably, once-weekly standard dose administration of V and reduction of T dose in VTD as consolidation therapy resulted in a dramatic decrease in the frequency of grade ≥3 PN (2%) and SR (1%). Reported rates of herpes zoster infection with VTD as both induction and consolidation therapy were 0.4% and 1%, respectively. Overall, the CR (≥VGPR) rate with VTD induction therapy was 19% (62%) vs 5% (31%) with TD (P 〈 0.001 for both CR and ≥VGPR comparisons); no pt had disease progression while on VTD, as compared to 5% of pts treated with TD (P 〈 0.001) who discontinued therapy and went off study. Progression through the subsequent treatment phases was associated with an increase in the frequency of CR and ≥VGPR up to a final value of 44% and 80%, respectively, in the VTD arm; the corresponding rates in the TD arm were 32% (p=0.02) and 65% (p=0.001), respectively. On an intention to treat basis, best responses in the VTD vs TD arm were the following: CR, 55% vs 38%, respectively (P 〈 0.001); ≥VGPR: 87% vs 69%, respectively (P 〈 0.001). Superiority of the VTD vs TD arm in terms of CR rate was confirmed in pts with high-risk cytogenetics, as defined by the presence of t(4;14) and/or del(17p) (58% vs 33%, respectively; p=0.004). Two year-projected PFS was 85% in the VTD arm as compared to 75% in TD (p=0.008). Improved PFS with VTD vs TD, both added to double ASCT, was consistent across subgroup analyses of pts with poor prognosis, including those with high-risk cytogenetic profiles (p=0.03; HR=0.42, 95% CI: 0.18 to 0.96). PFS curves for pts in the VTD arm who carried or not high-risk cytogenetics were similar (p=0.19). No difference in OS was seen between the two treatment groups, but longer follow up is required. Conclusions Incorporation of VTD into double ASCT for newly diagnosed MM resulted in a significant improvement in clinical outcomes (CR, ≥VGPR, PFS) in comparison with TD and double autotransplantation. Superior benefit with VTD and double ASCT in comparison with the control group was maintained in pts at high risk of progression or death, including those with t(4;14) and/or del(17p). Disclosures: Cavo: Celgene: Honoraria; Ortho Biotech, Janssen-Cilag: Honoraria, Research Funding, Speakers Bureau; Millennium Pharmaceuticals: Honoraria; Novartis: Honoraria.

Abstract: Complete response (CR) is an important objective of autologous stem-cell transplantation (ASCT) in multiple myeloma (MM). In comparison with conventional induction treatments, newer combinations of novel agents may effect increased rates of CR and near CR (nCR), a benefit potentially translating into even higher frequencies of CR/nCR after ASCT and improved clinical outcome. We designed a phase III study to detect an increase in CR+nCR rates from 10–15% with conventional Thalidomide-Dexamethasone (TD) to 20–30% with Velcade added to TD (VTD) in newly diagnosed MM. Both TD and VTD were given as three 21-day cycles in preparation for double ASCT. In the present analysis, CR+nCR rates by the two induction treatments were examined in relationship to baseline prognostic variables in 399 evaluable pts aged ≤65 years, of whom 199 randomized to VTD and 200 to TD. All analyses were intent to treat. In comparison with TD, VTD effected higher rates of CR+nCR (12% vs 33%, P & lt;0.001) and of ≥very good partial response (VGPR) (30% vs 61%, P & lt;0.001). By univariate analysis, superiority of VTD to TD was maintained across all sub-group analyses according to standard prognostic factors, including β2-m, albumin, stage (ISS), Hb, PLTs, bone marrow PC, M protein isotype, LDH, CRP. In particular, the rates of CR+nCR with VTD vs TD in pts with standard poor prognostic factors were as follows: ISS stage 3 (23.5% vs 6%, P=0.03), Hb & lt;10 g/dL (24% vs 4%, P=0.002), PLTs & lt;150.000/μL (35% vs 4%, P=0.009), bone marrow PC ≥50% (31% vs 13%, P & lt;0.001), IgA isotype (63% vs 15%, P & lt;0.001), LDH & gt;190 U/L (33% vs 9%, P & lt;0.001), CRP ≥8 mg/L (29% vs 10%, P=0.004). We next examined CR+nCRs by treatment arms in relationship to cytogenetics (FISH data available in 93% to 99% of all pts). Superior CR+nCR rates were effected by VTD vs TD in the presence of high-risk cytogenetics, including del(13) (39% vs 10%, P & lt;0.001), t(4;14) (39.5% vs 10%, P=0.002), combined t(4;14) and del(13) (32% vs 0%, P=0.001), and del(17p) (28.5% vs 0%, P=0.03). Remarkably, when examined in the context of the VTD arm, high-quality response rates were significantly higher for pts carrying del(13) and t(4;14) vs those who lacked these abnormalities [del(13): CR+nCR:39% vs 24%, P=0.03; ≥VGPR: 71% vs 48%, P=0.001] [t(4;14): ≥VGPR:79% vs 55%, P=0.007)] . An opposite trend was noted for pts in the TD arm, whose probability to attain ≥VGPR was adversely affected by the presence of del(13) (P=0.07) and del(17p) (P=0.03). Variables associated with achievement of CR+nCR in the two arms that retained statistical significance when assessed by multivariate Cox regression analysis included randomization to VTD (P & lt;0.001), light chain only subtype (P & lt;0.001), IgA isotype (P & lt;0.001) and Hb & gt;10 g/dL (P=0.01). In the VTD arm, a positive correlation was observed with del(13) (P=0.006) and t(4;14) (P=0.02). Response to first ASCT with melphalan 200 mg/m2 could be evaluated in 297 pts, of whom 145 randomized to VTD and 152 to TD. Randomization to VTD was closely associated with increased CR+nCR rates (54% vs 29% with TD, P & lt;0.001) and remained statistically significant (P & lt;0.001) also in the multivariate analysis. Additional factors predicting for superior post-ASCT CR+nCR rates in the multivariate setting included light chain only subtype (P & lt;0.001) and IgA isotype (P=0.005). We conclude that randomization to up-front VTD was the strongest and independent factor associated with increased rates of CR+nCR before ASCT. Superiority of VTD to TD pertained in both low-risk and high-risk sub-groups, including the traditionally unfavorable sub-groups carrying del(13), t(4,14) and del(17p). Remarkably, in the VTD arm improved postinduction CR+nCR rates were significantly associated with the presence of del(13) and t(4;14) in the multivariate analysis. Benefit from VTD vs TD as primary induction therapy translated into significantly improved CR+nCR rates after the first ASCT and remained statistically significant when assessed by multivariate analysis.

Abstract: The present study aimed to develop two survival risk scores (RS) for overall survival (OS, SRS KRd/EloRd ) and progression-free survival (PFS, PRS KRd/EloRd ) in 919 relapsed/refractory multiple myeloma (RRMM) patients who received carfilzomib, lenalidomide, and dexamethasone (KRd)/elotuzumab, lenalidomide, and dexamethasone (EloRd). The median OS was 35.4 months, with no significant difference between the KRd arm versus the EloRd arm. In the multivariate analysis, advanced ISS (HR = 1.31; P = 0.025), interval diagnosis–therapy (HR = 1.46; P = 0.001), number of previous lines of therapies (HR = 1.96; P & lt; 0.0001), older age (HR = 1.72; P & lt; 0.0001), and prior lenalidomide exposure (HR = 1.30; P = 0.026) remained independently associated with death. The median PFS was 20.3 months, with no difference between the two strategies. The multivariate model identified a significant progression/death risk increase for ISS III (HR = 1.37; P = 0.002), & gt;3 previous lines of therapies (HR = 1.67; P & lt; 0.0001), older age (HR = 1.64; P & lt; 0.0001), and prior lenalidomide exposure (HR = 1.35; P = 0.003). Three risk SRS KRd/EloRd categories were generated: low-risk (134 cases, 16.5%), intermediate-risk (467 cases, 57.3%), and high-risk categories (213 cases, 26.2%). The 1- and 2-year OS probability rates were 92.3% and 83.8% for the low-risk (HR = 1, reference category), 81.1% and 60.6% (HR = 2.73; P & lt; 0.0001) for the intermediate-risk, and 65.5% and 42.5% (HR = 4.91; P & lt; 0.0001) for the high-risk groups, respectively. Notably, unlike the low-risk group, which did not cross the median timeline, the OS median values were 36.6 and 18.6 months for the intermediate- and high-risk cases, respectively. Similarly, three PRS KRd/EloRd risk categories were engendered. Based on such grouping, 338 (41.5%) cases were allocated in the low-, 248 (30.5%) in the intermediate-, and 228 (28.0%) in the high-risk groups. The 1- and 2-year PFS probability rates were 71.4% and 54.5% for the low-risk (HR = 1, reference category), 68.9% and 43.7% (HR = 1.95; P & lt; 0.0001) for the intermediate-risk, and 48.0% and 27.1% (HR = 3.73; P & lt; 0.0001) for the high-risk groups, respectively. The PFS median values were 29.0, 21.0, and 11.7 months for the low-, intermediate-, and high-risk cases. This analysis showed 2.7- and 4.9-fold increased risk of death for the intermediate- and high-risk cases treated with KRd/EloRd as salvage therapy. The combined progression/death risks of the two categories were increased 1.3- and 2.2-fold compared to the low-risk group. In conclusion, SRS KRd/EloRd and PRS KRd/EloRd may represent accessible and globally applicable models in daily clinical practice and ultimately represent a prognostic tool for RRMM patients who received KRd or EloRd.

Abstract: Little is known as to how cells ensure that organelle size and number are coordinated to correctly couple organelle biogenesis to the demands of proliferation or differentiation. OA 1 is a melanosome‐associated G ‐protein‐coupled receptor involved in melanosome biogenesis during melanocyte differentiation. Cells lacking OA 1 contain fewer, but larger, mature melanosomes. Here, we show that OA 1 loss of function reduces both the basal expression and the α‐melanocyte‐stimulating hormone/c AMP ‐dependent induction of the microphthalmia‐associated transcription factor ( MITF ), the master regulator of melanocyte differentiation. In turn, this leads to a significant reduction in expression of PMEL , a major melanosomal structural protein, but does not affect tyrosinase and melanin levels. In line with its pivotal role in sensing melanosome maturation, OA 1 expression rescues melanosome biogenesis, activates MITF expression and thereby coordinates melanosome size and number, providing a quality control mechanism for the organelle in which resides. Thus, resident sensor receptors can activate a transcriptional cascade to specifically promote organelle biogenesis.

Abstract: The recent introduction of monoclonal antibodies (MoAbs), with several cellular targets, such as CD-38 (daratumumab and isatuximab) and SLAM F7 (elotuzumab), differently combined with other classes of agents, has significantly extended the outcomes of patients with multiple myeloma (MM) in different phases of the disease. Initially used in advanced/refractory patients, different MoAbs combination have been introduced in the treatment of newly diagnosed transplant eligible patients (NDTEMM), showing a significant improvement in the depth of the response and in survival outcomes, without a significant price in terms of toxicity. In smoldering MM, MoAbs have been applied, either alone or in combination with other drugs, with the goal of delaying the progression to active MM and restoring the immune system. In this review, we will focus on the main results achieved so far and on the main on-going trials using MoAbs in SMM and NDTEMM.

Abstract: Background Despite an improvement in treatment response, high-risk multiple myeloma (MM) patients (pts) experience early relapse and short disease-free survival. Together with more validated high-risk features, high levels of circulating plasma cells (high CPC) have been considered a marker of aggressive disease and poor outcome (F. Gay et al, ASH 2019; W.I. Gonsalves et al, Am J Hematol 2020). To date, there are no uniform data on the optimal cut-off predictive of clinical outcome. No prospective data on CPC are available in the setting of novel-drug clinical trials with comprehensive baseline evaluation and minimal residual disease (MRD) assessment. Aims 1) To identify the best cut-off for CPC to predict progression-free survival (PFS); 2) to assess the impact of high CPC levels on the clinical outcome of newly diagnosed (ND)MM pts in the context of concomitant risk features and MRD evaluation. Methods In the multicenter randomized FORTE clinical trial, 474 NDMM pts ≤65 years were randomized (R1) to receive either: carfilzomib-lenalidomide-dexamethasone (KRd) induction-autologous stem-cell transplant-KRd consolidation (KRd_ASCT); KRd for 12 cycles (KRd12); or carfilzomib-cyclophosphamide-dexamethasone (KCd) induction-ASCT-KCd consolidation (KCd_ASCT). Thereafter, pts were randomized (R2) to maintenance treatment with lenalidomide alone (R) or plus carfilzomib (KR). MRD was assessed by 2nd-generation multiparameter flow cytometry (MFC, sensitivity 10-5) in pts who achieved ≥very good partial response before maintenance and then every 6 months. At diagnosis, single-platform FC was used to sort and count CPC. Receiver Operating Characteristic (ROC) analysis was used to define a cut-off based on PFS at 36 months as outcome. Correlations between high CPC and the most important baseline prognostic features (age, International Staging System (ISS), lactate dehydrogenase (LDH), chromosomal abnormalities (CA) by FISH [(del17p, t(4;14), t(14;16), t(11;14), amp1q, del1p, del13], Revised-ISS (R-ISS)) were explored. Hence, we performed a multivariate (MV) analysis to assess the impact of high CPC on the achievement of MRD negativity, on PFS and OS. Finally, we evaluated the impact of baseline CPC and MRD achievement. Results CPC analysis was performed in 401/474 pts at diagnosis; median follow-up was 44.2 months (39.6-47.9) and baseline features were similar to those reported in the overall FORTE population. Median CPC were 0.02% (IQR 0-0.14). The optimal CPC cut-off to predict PFS (ROC analysis) was 0.07% (5 cells/ul, 0.005 x109/l) and was consistent with a cut-off previously identified as a predictor of sustained MRD negativity (MRDsus12; L. Bertamini et al, EHA 2020). High-CPC pts ( & gt;0.07%) were 130/401 (32%), while 271/401 (68%) had low CPC (≤0.07%). The proportion of high-CPC pts was comparable among treatment arms. Baseline features significantly associated with high CPC in a MV analysis were: ISS II/III, high LDH, amp1q, t(4;14), t(14;16) and bone marrow plasma cells ( & gt;60%). Regarding PFS, in a MV analysis adjusted for R-ISS and R1 treatment, including all the baseline features, high CPC were associated with a lower PFS (HR 2.49, 95% CI 1.76-3.51, P & lt;0.0001; 3-year PFS rates 47% for high CPC vs 78% for low CPC; Fig. 1A). Similarly, patients with high CPC had a worse OS compared with patients with low CPC (3-year OS rates 78% for high CPC vs 93% for low CPC; HR 2.85, 95% CI 1.56-5.19, P=0.0006; Fig. 1B). The impact of baseline CPC levels on PFS was consistent in all high-risk subgroups (Fig. 1C), except in those patients who achieved pre-maintenance MRD negativity [(neg); interaction P=0.03]. Low-CPC and MRD-neg pts showed the best outcome with a 3-year PFS of 84%. Low-CPC MRD-positive (pos) and high-CPC MRD-neg pts had similar 3-year PFS (70% vs 68%). High-CPC MRD-pos pts had a dismal outcome (3-year PFS 32%; Fig. 1D). Conclusion High CPC with a cut-off of 0.07% (5 cells/ul, 0.005 x109/l) is a strong and independent high-risk factor, predicting a shorter PFS and OS even in the context of other high-risk features. The achievement of MRD neg independently improved the poor prognosis of high-CPC patients. Figure 1 Disclosures D'Agostino: GSK: Membership on an entity's Board of Directors or advisory committees. Galieni:Janssen: Honoraria; AbbVie: Honoraria; Takeda: Honoraria; Celgene: Honoraria. Molica:Gilead: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Roche: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Tacchetti:Oncopeptides: Honoraria; AbbVie: Honoraria; Takeda: Honoraria; Amgen: Honoraria; Bristol-Myers Squibb: Honoraria; Celgene: Honoraria; Janssen: Honoraria. Musto:Amgen: Honoraria; Celgene: Honoraria. Gay:GSK: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees; Adaptive: Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees; Oncopeptides: Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees. Boccadoro:GlaxoSmithKline: Membership on an entity's Board of Directors or advisory committees; Sanofi: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding; AbbVie: Honoraria; Mundipharma: Research Funding. Oliva:Adaptive Biotechnologies: Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria; Takeda: Membership on an entity's Board of Directors or advisory committees. OffLabel Disclosure: The presentation includes discussion of off-label use of a drug or drugs for the treatment of multiple myeloma (including carfilzomib, cyclophosphamide, lenalidomide and dexamethasone).