Abstract: 8046 Background: As treatments advance in multiple myeloma (MM) and increasingly deeper and longer responses are achieved, the definition of what a cure is becomes increasingly relevant. While many physicians quote that patients may achieve a “functional cure”, understanding the patient perspective on the concept of cure has yet to be explored. Methods: HealthTree Cure Hub by the HealthTree Foundation represents an online portal for patients with plasma cell dyscrasias to help navigate their disease. It is the largest single database of patients with multiple myeloma with over 10,200 patients as of January 2022. Using this platform, we surveyed patients online from November 11 th 2021 to Feb 7 th 2022. Varying scenarios incorporating toxicity, disease status, and being on/off treatment were presented, and participants were asked to rate them from 1-5, with 5 being an ideal cure. Patient awareness of the term functional or operational cure was also. Results: A total of 1525 participants completed the survey. Table lists characteristics of the patients who completed this survey. The majority of the patients were female (55.5%), college educated (88.5%) and non-Hispanic White (70.7%). Most patients rated being off treatment permanently and having no evidence of disease as a cure (1116/1469, 75.5%), with a median score of 5 amongst respondents, indicating an ideal version of cure. Continuing to take the same pill or injection with significant toxicity and no evidence of disease had a median score of 1, a score lower than either “continuing to take same pill or injection without significant toxicity even in the evidence of disease” (median score 2) or “stopping treatment permanently even with some detectable disease” (median score 2). The majority of patients (76.3%) reported being unfamiliar with the term functional or operational cure. Conclusions: In the first study of patients with plasma cell dyscrasias in which patients were asked about their perceptions of what a cure is, our results highlight that drug toxicity and being on treatment profoundly impacts patient's perception of cure. Furthermore, most patients are not familiar with the term functional or operational cure. Future efforts should recruit more diverse patient populations and incorporate patient preferences in approaches to defining cure in myeloma, as well as explaining cure in easily comprehensible terms to patients. [Table: see text]

Abstract: Introduction: Daratumumab (DARA) is approved across lines of therapy for multiple myeloma. In the primary analysis of the phase 2 GRIFFIN trial (NCT02874742) in pts with transplant-eligible NDMM (median follow-up, 13.5 mo), D-RVd improved the rate of stringent complete response (sCR) by the end of post-autologous stem cell transplant (ASCT) consolidation versus RVd (42.4% vs 32.0%; odds ratio [OR], 1.57; 95% CI, 0.87-2.82; 1-sided P=0.068) (Voorhees PM, et al. Blood. 2020). With longer follow-up (median, 27.4 mo) after 12 months of maintenance therapy, sCR rates deepened for D-RVd versus RVd (63.6% vs 47.4%, 2-sided P=0.0253), as did the rate of minimal residual disease (MRD; 10 -5) negativity (62.5% vs 27.2%, P & lt;0.0001) (Kaufman JL, et al. Blood. 2020). Here, we present an analysis among clinically relevant subgroups (age ≥65 years, International Staging System [ISS] stage III disease, and high cytogenetic risk [del17p, t(4;14), or t(14;16) abnormalities] ) after 24 months of maintenance therapy (median follow-up, 38.6 mo). Methods: Eligible pts with transplant-eligible NDMM were randomized 1:1 to D-RVd or RVd. Pts received 4 RVd or D-RVd induction cycles, high dose therapy, ASCT, 2 RVd or D-RVd consolidation cycles, and maintenance with lenalidomide (R) alone or with DARA (D-R) for 24 months. During induction and consolidation (21-day cycles), pts received R (25 mg PO on Days 1-14), bortezomib (1.3 mg/m 2 SC on Days 1, 4, 8, and 11), and dexamethasone (40 mg PO QW) ± DARA (16 mg/kg IV on Days 1, 8, and 15 of Cycles 1-4 and Day 1 of Cycles 5-6). During maintenance (Cycles 7-32; 28-day cycles), pts received R (10 mg PO on Days 1-21; if tolerated, 15 mg in Cycles 10+) ± DARA (16 mg/kg IV Q8W, or Q4W per pt decision after Amendment 2) until disease progression or up to 24 months. The primary endpoint was sCR rate by the end of post-ASCT consolidation. Responses were assessed per International Myeloma Working Group criteria by a validated computer algorithm. Additional endpoints included progression-free survival (PFS) and MRD-negativity (10 -5) rate by next-generation sequencing. Results: In total, 207 pts were randomized (D-RVd, n=104; RVd, n=103); each group had a similar number of pts with age ≥65 years (n=28; n=28), ISS stage III disease (n=14; n=14), or high cytogenetic risk (n=16; n=14). Among response-evaluable pts, the rate of sCR after 24 months of maintenance therapy was numerically higher for D-RVd versus RVd among pts ≥65 years (63.0% vs 40.7%, OR, 2.47, 95% CI, 0.83-7.39), but similar for D-RVd and RVd pts with ISS stage III disease (57.1% vs 61.5%, OR, 0.83, 95% CI, 0.18-3.88) and high cytogenetic risk (43.8% vs 38.5%, OR, 1.24, 95% CI, 0.28-5.53; Figure). MRD-negativity (10 -5) rates favored D-RVd versus RVd across all subgroups: ≥65 years (67.9% vs 17.9%), ISS stage III disease (71.4% vs 35.7%), and high cytogenetic risk (43.8% vs 28.6%; Figure). With 38.6 months median follow-up, median PFS was not reached (NR) for pts ≥65 years in either treatment group (6 pts progressed: D-RVd, n=1; RVd, n=5). Among pts with ISS stage III disease, median PFS was NR for D-RVd and 33.1 months for RVd (7 pts progressed: D-RVd, n=1; RVd, n=6). Among pts with high cytogenetic risk, median PFS was NR for D-RVd and 36.1 months for RVd (10 pts progressed: D-RVd, n=5; RVd, n=5; Figure). In pts ≥65 years, grade 3/4 treatment-emergent adverse events (TEAEs) occurred in 88.9% of D-RVd pts and 77.8% of RVd pts; the most common (≥20%) were neutropenia (37.0%; 29.6%) and lymphopenia (25.9%; 11.1%). Serious TEAEs occurred in 55.6% and 40.7% of pts, respectively. TEAEs led to study treatment discontinuation in 33.3% of D-RVd pts and 25.9% of RVd pts. One death due to a TEAE (unrelated to study treatment) occurred in a D-RVd pt ≥65 years of age. Conclusion: Subgroup analyses of pts in GRIFFIN show that the addition of DARA to RVd induction/consolidation and R maintenance, in conjunction with ASCT, may benefit clinically relevant subgroups. sCR rates were improved for D-RVd versus RVd in pts ≥65 years but not in pts with ISS stage III disease or high cytogenetic risk. Improved MRD-negativity rates were observed for D-RVd in all subgroups. Although immature and with limited pt numbers, PFS results also trended towards favoring D-RVd in these subgroups. Among pts ≥65 years, TEAEs and serious TEAEs were numerically higher for D-RVd. These results support the use of DARA in transplant-eligible NDMM pts among high-risk subgroups, although larger studies are needed. Figure 1 Figure 1. Disclosures Anderson: Celgene, BMS, Janssen, GSK, Karyopharm, Oncopeptides, Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Kaufman: Sutro, Takeda: Research Funding; Roche/Genetech, Tecnopharma: Consultancy, Honoraria; Janssen: Honoraria; Novartis: Research Funding; Heidelberg Pharma: Research Funding; Incyte, celgene: Consultancy; BMS: Consultancy, Research Funding; Amgen: Research Funding; Tecnofarma SAS, AbbVie: Honoraria; Fortis Therapeutics: Research Funding; Incyte, TG Therapeutics: Membership on an entity's Board of Directors or advisory committees; Genentech, AbbVie, Janssen: Consultancy, Research Funding. Sborov: Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; GlaxoSmithKline: Consultancy; SkylineDx: Consultancy; Sanofi: Consultancy. Reeves: Pharma Essentia: Consultancy, Honoraria; Takeda: Honoraria; Bristol-Myers Squibb: Speakers Bureau; Incyte Corporation: Honoraria. Rodriguez: Takeda: Consultancy, Speakers Bureau; Oncopeptides: Consultancy, Honoraria; Amgen: Consultancy, Speakers Bureau; Janssen: Consultancy, Speakers Bureau; Karyopharm: Consultancy, Speakers Bureau; BMS: Consultancy, Speakers Bureau. Chari: Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees; Shattuck Labs: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Secura Bio: Consultancy, Membership on an entity's Board of Directors or advisory committees; GlaxoSmithKline: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Research Funding; AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Millenium/Takeda: Consultancy, Research Funding; BMS/Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Karyopharm: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen Oncology: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Antengene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Sanofi Genzyme: Consultancy, Membership on an entity's Board of Directors or advisory committees; Oncopeptides: Consultancy, Membership on an entity's Board of Directors or advisory committees. Silbermann: Sanofi Genzyme: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees. Costa: Karyopharm: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria; Amgen: Consultancy, Honoraria, Research Funding, Speakers Bureau; BMS: Consultancy, Honoraria, Research Funding; Sanofi: Consultancy, Honoraria, Speakers Bureau; Janssen: Consultancy, Honoraria, Research Funding. Shah: Janssen: Research Funding; Nektar: Research Funding; Kite: Consultancy; Karyopharm: Consultancy; Indapta Therapeutics: Consultancy; Bluebird Bio: Research Funding; BMS/Celgene: Research Funding; Amgen: Consultancy; CareDx: Consultancy; Poseida: Research Funding; Precision Biosciences: Research Funding; Oncopeptides: Consultancy; CSL Behring: Consultancy; GSK: Consultancy; Sanofi: Consultancy; Sutro Biopharma: Research Funding; Teneobio: Research Funding. Bumma: Janssen: Membership on an entity's Board of Directors or advisory committees; Amgen: Speakers Bureau; Sanofi: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Holstein: Oncopeptides: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Genentech, GSK, Janssen, Secura Bio, Sorrento: Honoraria; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees. Jakubowiak: Celgene: Membership on an entity's Board of Directors or advisory committees; Gracell: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; GSK: Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees; Karyopharm: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees. Wildes: Carevive: Consultancy; Seattle Genetics: Consultancy; Sanofi: Consultancy; Janssen: Consultancy. Orlowski: Amgen, Inc., BioTheryX, Inc., Bristol-Myers Squibb, Celgene, EcoR1 Capital LLC, Genzyme, GSK Biologicals, Janssen Biotech, Karyopharm Therapeutics, Inc., Neoleukin Corporation, Oncopeptides AB, Regeneron Pharmaceuticals, Inc., Sanofi-Aventis, and Takeda P: Consultancy, Honoraria; Asylia Therapeutics, Inc., BioTheryX, Inc., and Heidelberg Pharma, AG.: Other: Laboratory research funding; CARsgen Therapeutics, Celgene, Exelixis, Janssen Biotech, Sanofi-Aventis, Takeda Pharmaceuticals North America, Inc.: Other: Clinical research funding; Asylia Therapeutics, Inc.: Current holder of individual stocks in a privately-held company, Patents & Royalties; Amgen, Inc., BioTheryX, Inc., Bristol-Myers Squibb, Celgene, Forma Therapeutics, Genzyme, GSK Biologicals, Janssen Biotech, Juno Therapeutics, Karyopharm Therapeutics, Inc., Kite Pharma, Neoleukin Corporation, Oncopeptides AB, Regeneron Pharmaceuticals, I: Membership on an entity's Board of Directors or advisory committees. Shain: Sanofi Genzyme: Consultancy, Speakers Bureau; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Adaptive Biotechnologies Corporation: Consultancy, Speakers Bureau; Novartis Pharmaceuticals Corporation: Consultancy; GlaxoSmithLine, LLC: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BMS: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Karyopharm Therapeutics Inc.: Honoraria, Research Funding; Amgen Inc: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen oncology: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Cowan: BMS: Research Funding; Secura Bio: Consultancy; GSK: Consultancy; Harpoon: Research Funding; Cellectar: Consultancy; Sanofi: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Nektar: Research Funding. Pei: Janssen: Current Employment, Current equity holder in publicly-traded company. Cortoos: Janssen: Current Employment, Current equity holder in publicly-traded company. Patel: Janssen: Current Employment. Bartlett: Janssen: Current Employment. Vermeulen: Janssen: Current Employment, Current equity holder in publicly-traded company. Lin: Janssen: Current Employment. Voorhees: Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Sanofi: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Karyopharm: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Oncopeptides: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; GlaxoSmithKline: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Secura Bio: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Richardson: AbbVie: Consultancy; Oncopeptides: Consultancy, Research Funding; Celgene/BMS: Consultancy, Research Funding; Regeneron: Consultancy; AstraZeneca: Consultancy; Secura Bio: Consultancy; Janssen: Consultancy; Protocol Intelligence: Consultancy; Karyopharm: Consultancy, Research Funding; Takeda: Consultancy, Research Funding; GlaxoSmithKline: Consultancy; Sanofi: Consultancy; Jazz Pharmaceuticals: Consultancy, Research Funding. OffLabel Disclosure: The specific regimen combination is not yet approved, but individual components are.

Abstract: Introduction: DARA, a human IgGκ monoclonal antibody targeting CD38, is approved as monotherapy and in combination with standard-of-care (SoC) regimens for multiple myeloma (MM). In randomized studies, DARA-based regimens significantly improved response rates, depth of response including minimal residual disease (MRD) negativity, and progression-free survival (PFS) in NDMM and relapsed/refractory MM pts. RVd followed by high-dose therapy (HDT), autologous stem cell transplant (ASCT), and consolidation is a SoC regimen for US pts with NDMM. This phase 2, randomized study (GRIFFIN; NCT02874742) evaluated DARA plus RVd (D-RVd) in ASCT-eligible NDMM pts. A 16-pt safety run-in showed no safety concerns. Here, we present results that adding DARA to RVd improves responses rapidly, including depth of response, which increases with longer duration of therapy. Methods: Pts were randomized 1:1 to RVd ± DARA, stratified by ISS stage and creatinine clearance. Pts received 4 induction cycles, HDT, ASCT, 2 consolidation cycles, and maintenance with R ± DARA for 24 mo. During induction and consolidation (Cycles 1-6), pts received R 25 mg PO on Days 1-14; V 1.3 mg/m2 SC on Days 1, 4, 8, and 11; and d 40 mg QW every 21 days. DARA 16 mg/kg IV was given on Days 1, 8, and 15 of Cycles 1-4 and Day 1 of Cycles 5-6. During maintenance (Cycles 7-32), pts received R 10 mg (15 mg in Cycles 10+ if tolerated) on Days 1-21 every 28 days ± DARA 16 mg/kg IV Q8W (or Q4W per pt decision after Amendment 2). The primary endpoint was the stringent complete response (sCR) rate by the end of consolidation per IMWG computer algorithm. The study had 80% power to detect a 15% improvement with a 1-sided alpha of 0.1 (equivalent to 2-sided alpha of 0.2). MRD (10-5 per IMWG criteria) was assessed by next-generation sequencing (clonoSEQ; Adaptive Biotechnologies). Results: A total of 207 pts (D-RVd n = 104; RVd n =103) were randomized. Baseline demographics and disease characteristics were well balanced between arms. Median age was 60 yrs; 48%, 37%, and 14% of pts were ISS stage I, II, or III, respectively; 30 (15%) pts had high cytogenetic risk defined by FISH for del(17p), t(4;14), or t(14;16). The study met its primary endpoint; D-RVd improved the sCR rate by the end of consolidation (42.4% vs 32.0%; odds ratio 1.57; 95% CI, 0.87-2.82; 2-sided P = 0.1359); at the pre-set 2-sided alpha of 0.2. This improvement was observed in all pt subgroups except for the small subsets of ISS stage III or high-cytogenetic risk pts. Responses deepened over time (Figure); the sCR rate was 12% vs 7% with D-RVd vs RVd at the end of induction, increasing to 21% vs 14% after ASCT, and 50% vs 37% at the clinical cutoff (CCO; 13.5 mo median follow-up). D-RVd achieved higher overall response (99% vs 92%), ≥VGPR (91% vs 73%), and ≥CR (52% vs 42%) rates vs RVd by the end of consolidation. At the end of induction, 8/19 (42%) pts achieving ≥CR with D-RVd were MRD negative, compared to 1/13 (8%) pts achieving ≥CR with RVd. At the end of consolidation, 30/51 (59%) pts achieving ≥CR with D-RVd were MRD negative vs 10/41 (24%) pts achieving ≥CR with RVd. Due to the short median follow-up at CCO, PFS and OS were immature, with 6 PFS events in each arm. Median stem cell yield was 8.1 vs 9.4 × 106 cells/kg for D-RVd vs RVd. Median (range) time to platelet engraftment was 13 (2-31) and 12 (1-23) days for D-RVd vs RVd; median (range) time to neutrophil engraftment was 12 (3-31) and 12 (2-23) days for D-RVd vs RVd. Grade 3/4 TEAEs (≥10%) with D-RVd vs RVd included neutropenia (32% vs 15%), lymphopenia (23% vs 23%), thrombocytopenia (16% vs 8%), and leukopenia (15% vs 7%). There was no difference in the rate of grade 3/4 infections between arms. IRRs occurred in 41% of DARA-treated pts, which were primarily grade 1-2. Updated data will be presented. Conclusions: These data demonstrate that adding DARA to RVd significantly improves response rates and depth of response, including sCR and MRD negativity. As seen in other randomized studies, continued use of daratumumab improved depth of response. The overall safety profile of D-RVd is consistent with previous reports with DARA plus SoC. Likewise, similar to what was reported from CASSIOPEIA, stem cell mobilization and ASCT are feasible with D-RVd, without a significant effect on hematopoietic reconstitution. The study is ongoing, with pts continuing maintenance therapy. Disclosures Voorhees: BMS: Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Janssen: Honoraria, Research Funding; GSK: Research Funding; Novartis: Consultancy; Oncopeptides: Consultancy; Takeda: Honoraria, Research Funding; TeneBio: Honoraria, Research Funding; Adaptive Biotechnologies: Honoraria. Kaufman:Pharmacyclics: Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy; Winship Cancer Institute of Emory University: Employment; Takeda: Consultancy; Janssen: Honoraria; Bristol-Myers Squibb: Consultancy; Incyte: Consultancy; Karyopharm: Membership on an entity's Board of Directors or advisory committees; TG Therapeutics: Consultancy; AbbVie: Consultancy; Amgen: Consultancy. Sborov:Celgene: Honoraria; Janssen: Consultancy. Reeves:Celgene: Honoraria, Speakers Bureau; Takeda: Consultancy, Honoraria; Incyte: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria. Rodriguez:Takeda, Amgen: Consultancy, Speakers Bureau. Chari:Janssen, Celgene, Novartis Pharmaceuticals, Amgen, Bristol Myers Squibb, Pharmacyclics, Karyopharm, Sanofi, Seattle Genetics, OncoPeptides, Millenium/Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Silbermann:Janssen, Sanofi: Other: Consultant/Advisor. Costa:Amgen: Consultancy, Honoraria, Research Funding, Speakers Bureau; Janssen: Research Funding, Speakers Bureau; Celgene: Consultancy, Honoraria, Research Funding; Sanofi: Consultancy, Honoraria, Speakers Bureau; GSK: Consultancy, Honoraria, Research Funding; Abbvie: Consultancy; Karyopharm: Consultancy; Fujimoto Pharmaceutical Corporation Japan: Other: Advisor. Anderson:Amgen, Janssen, Takeda, Celgene: Consultancy, Speakers Bureau. Shah:Bristol-Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Nkarta: Consultancy, Membership on an entity's Board of Directors or advisory committees; Kite: Consultancy, Membership on an entity's Board of Directors or advisory committees; Teneobio: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene, Janssen, Bluebird Bio, Sutro Biopharma: Research Funding; Poseida: Research Funding; Indapta Therapeutics: Equity Ownership; University of California, San Francisco: Employment; Genentech, Seattle Genetics, Oncopeptides, Karoypharm, Surface Oncology, Precision biosciences GSK, Nektar, Amgen, Indapta Therapeutics, Sanofi: Membership on an entity's Board of Directors or advisory committees. Efebera:Takeda: Honoraria; Akcea: Other: Advisory board, Speakers Bureau; Janssen: Speakers Bureau. Costello:Takeda: Honoraria, Research Funding; Janssen: Research Funding; Celgene: Consultancy, Honoraria, Research Funding. Jakubowiak:Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; GSK: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; KaryoPharm Therapeutics: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Juno: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; SkyLineDx: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Millennium: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Adaptive Biotechnologies: Consultancy, Honoraria; Sanofi: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Wildes:Carevive: Consultancy; Janssen: Research Funding. Orlowski:BioTheryX, Spectrum Pharma: Research Funding; Bristol-Myers Squibb: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Kita Pharma: Consultancy, Membership on an entity's Board of Directors or advisory committees; Ionis Pharmaceuticals; Legend Biotech; Molecular Partners; Servier: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy; Sanofi-Aventis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees. Shain:Celgene: 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; Adaptive Biotechnologies: Consultancy; Takeda: Membership on an entity's Board of Directors or advisory committees; AbbVie: Research Funding; Amgen: Membership on an entity's Board of Directors or advisory committees; Sanofi Genzyme: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees. Cowan:Janssen: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Abbvie: Research Funding; Juno: Research Funding; Sanofi: Consultancy; Cellectar: Consultancy. Murphy:Janssen: Employment, Equity Ownership. Lutska:Janssen: Employment. Pei:Janssen: Employment, Equity Ownership. Ukropec:Janssen: Employment, Equity Ownership. Vermeulen:Janssen R & D, LLC: Employment, Equity Ownership. de Boer:Janssen: Employment, Equity Ownership. Hoehn:Janssen: Employment, Equity Ownership. Lin:Janssen: Employment, Equity Ownership. Richardson:Karyopharm: Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; 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; Oncopeptides: Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Research Funding. OffLabel Disclosure: D-RVd is being investigated in transplant-eligible NDMM

Abstract: Introduction: DARA is approved for NDMM and previously treated MM. In the primary analysis of the phase 2 GRIFFIN trial (NCT02874742) in autologous stem cell transplant (ASCT)-eligible NDMM pts (median follow-up, 13.5 mo), DARA plus RVd (D-RVd) improved the rate of stringent complete response (sCR) by the end of post-ASCT consolidation versus RVd (42.4% vs 32.0%, 1-sided P=0.068) (Voorhees PM, et al. Blood. 2020). With longer follow-up (median, 27.4 mo), responses deepened and were improved for D-RVd versus RVd (sCR rate: 63.6% vs 47.4%, 2-sided P=0.0253), as did the MRD-negativity (10 -5) rate (62.5% vs 27.2%, P & lt;0.0001) (Kaufman JL, et al. Blood. 2020). Here, we present updated efficacy and safety results after 24 months of maintenance therapy or treatment discontinuation (median follow-up, 38.6 mo). Methods: Pts with NDMM eligible for high-dose therapy (HDT) and ASCT were randomized 1:1 to receive RVd or D-RVd, stratified by ISS disease stage (I, II, or III) and creatinine clearance (30-50 or & gt;50 mL/min). Pts received 4 RVd or D-RVd induction cycles, HDT, ASCT, 2 RVd or D-RVd consolidation cycles, and maintenance with lenalidomide (R) alone or with DARA (D-R) for 24 months. During induction and consolidation (21-day cycles), pts received R (25 mg PO on Days 1-14), bortezomib (1.3 mg/m 2 SC on Days 1, 4, 8, and 11), and dexamethasone (40 mg PO QW) ± DARA (16 mg/kg IV on Days 1, 8, and 15 of Cycles 1-4 and Day 1 of Cycles 5-6). During maintenance (Cycles 7-32; 28-day cycles), pts received R (10 mg PO on Days 1-21; if tolerated, 15 mg in Cycle 10+) ± DARA (16 mg/kg IV) Q8W (or Q4W per pt decision after protocol amendment 2) until disease progression or up to 24 months. The primary endpoint was sCR rate by the end of post-ASCT consolidation (tested at 1-sided α of 0.10). Responses were assessed per IMWG criteria by a validated computer algorithm. Key secondary endpoints included progression-free survival (PFS) and MRD negativity assessed by NGS at the minimum sensitivity threshold of 10 -5, at suspected complete response or better (≥CR), at the end of induction and consolidation, and after 12 and 24 months of maintenance, regardless of response. Secondary analyses were evaluated using 2-sided α of 0.05, not adjusted for multiplicity. Results: In total, 207 pts were randomized (D-RVd, n=104; RVd, n=103); baseline characteristics were well balanced. After 24 months of D-R or R maintenance therapy, the rate of sCR favored D-RVd versus RVd in the response-evaluable population (66.0% [66/100] vs 47.4% [46/97] , 2-sided P=0.0096; Figure). In the intent-to-treat (ITT) population, MRD-negativity (10 -5) rates also remained higher for D-RVd versus RVd (64.4% [67/104] vs 30.1% [31/103] , P & lt;0.0001), as well as among pts who achieved ≥CR (78.0% [64/82] vs 47.5% [28/59] , P=0.0003). Similarly, MRD-negativity (10 -6) rates favored D-RVd versus RVd in the ITT population (35.6% vs 14.6%, P=0.0007; Figure), as well as among pts who achieved ≥CR (42.7% vs 22.0%, P=0.0121). The rate of sustained MRD negativity (10 -5) lasting ≥12 months in the ITT population was & gt;3-fold higher for D-RVd versus RVd (44.2% vs 12.6%, P & lt;0.0001). With 38.6 months follow-up, median PFS was not reached in either arm but trended towards favoring D-RVd versus RVd (hazard ratio, 0.46; 95% CI, 0.21-1.01; Figure). The estimated 36-month PFS rate was 88.9% for D-RVd and 81.2% for RVd. In total, 14 pts died (D-RVd, n=7; RVd, n=7), 9 from progressive disease (D-RVd, n=5; RVd, n=4). No new safety concerns were observed with extended follow-up. In total, 86.9% (86/99) of D-RVd pts and 79.4% (81/102) of RVd pts developed grade 3/4 treatment-emergent adverse events (TEAEs). Serious TEAEs occurred in 46.5% of D-RVd pts and 52.0% of RVd pts. TEAEs led to discontinuation of study treatment at the same rate (D-RVd, 34.3%; RVd, 34.3%). One pt in each group died due to TEAEs, neither related to study treatment. Conclusion: After 24 months of maintenance therapy, the addition of DARA to RVd induction and consolidation in conjunction with ASCT, followed by DARA plus R maintenance, continued to demonstrate deep and durable responses in pts with transplant-eligible NDMM, including sCR and MRD-negativity (10 -5 and 10 -6) rates. While this study was not powered for PFS, there is a positive trend towards improved PFS in the D-RVd group. No new safety concerns were observed with longer follow-up. These results support the use of D-RVd induction/consolidation and D-R maintenance in transplant-eligible NDMM pts. Figure 1 Figure 1. Disclosures Kaufman: Sutro, Takeda: Research Funding; Incyte, TG Therapeutics: Membership on an entity's Board of Directors or advisory committees; BMS: Consultancy, Research Funding; Amgen: Research Funding; Tecnofarma SAS, AbbVie: Honoraria; Janssen: Honoraria; Fortis Therapeutics: Research Funding; Novartis: Research Funding; Incyte, celgene: Consultancy; Heidelberg Pharma: Research Funding; Roche/Genetech, Tecnopharma: Consultancy, Honoraria; Genentech, AbbVie, Janssen: Consultancy, Research Funding. Sborov: Sanofi: Consultancy; SkylineDx: Consultancy; GlaxoSmithKline: Consultancy; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees. Reeves: Bristol-Myers Squibb: Speakers Bureau; Incyte Corporation: Honoraria; Takeda: Honoraria; Pharma Essentia: Consultancy, Honoraria. Rodriguez: Janssen: Consultancy, Speakers Bureau; BMS: Consultancy, Speakers Bureau; Karyopharm: Consultancy, Speakers Bureau; Takeda: Consultancy, Speakers Bureau; Amgen: Consultancy, Speakers Bureau; Oncopeptides: Consultancy, Honoraria. Chari: Oncopeptides: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Karyopharm: Consultancy, Membership on an entity's Board of Directors or advisory committees; GlaxoSmithKline: Consultancy, Membership on an entity's Board of Directors or advisory committees; Shattuck Labs: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Research Funding; AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Secura Bio: Consultancy, Membership on an entity's Board of Directors or advisory committees; Sanofi Genzyme: Consultancy, Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Research Funding; Antengene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees; Millenium/Takeda: Consultancy, Research Funding; Janssen Oncology: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics: Research Funding; BMS/Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Silbermann: Janssen Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Sanofi Genzyme: Membership on an entity's Board of Directors or advisory committees, Research Funding. Costa: Pfizer: Consultancy, Honoraria; Karyopharm: Consultancy, Honoraria; BMS: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Sanofi: Consultancy, Honoraria, Speakers Bureau; Amgen: Consultancy, Honoraria, Research Funding, Speakers Bureau. Anderson: Celgene, BMS, Janssen, GSK, Karyopharm, Oncopeptides, Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Shah: GSK: Consultancy; Nektar: Research Funding; Kite: Consultancy; CareDx: Consultancy; CSL Behring: Consultancy; Indapta Therapeutics: Consultancy; Janssen: Research Funding; Poseida: Research Funding; Karyopharm: Consultancy; BMS/Celgene: Research Funding; Bluebird Bio: Research Funding; Oncopeptides: Consultancy; Teneobio: Research Funding; Sanofi: Consultancy; Precision Biosciences: Research Funding; Sutro Biopharma: Research Funding; Amgen: Consultancy. Bumma: Janssen: Membership on an entity's Board of Directors or advisory committees; Amgen: Speakers Bureau; Sanofi: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Holstein: Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Genentech, GSK, Janssen, Secura Bio, Sorrento: Honoraria; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Oncopeptides: Membership on an entity's Board of Directors or advisory committees, Research Funding. Jakubowiak: Abbvie: Membership on an entity's Board of Directors or advisory committees; Karyopharm: Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees; GSK: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Gracell: Membership on an entity's Board of Directors or advisory committees. Wildes: Carevive: Consultancy; Seattle Genetics: Consultancy; Sanofi: Consultancy; Janssen: Consultancy. Orlowski: Asylia Therapeutics, Inc., BioTheryX, Inc., and Heidelberg Pharma, AG.: Other: Laboratory research funding; CARsgen Therapeutics, Celgene, Exelixis, Janssen Biotech, Sanofi-Aventis, Takeda Pharmaceuticals North America, Inc.: Other: Clinical research funding; Asylia Therapeutics, Inc.: Current holder of individual stocks in a privately-held company, Patents & Royalties; Amgen, Inc., BioTheryX, Inc., Bristol-Myers Squibb, Celgene, Forma Therapeutics, Genzyme, GSK Biologicals, Janssen Biotech, Juno Therapeutics, Karyopharm Therapeutics, Inc., Kite Pharma, Neoleukin Corporation, Oncopeptides AB, Regeneron Pharmaceuticals, I: Membership on an entity's Board of Directors or advisory committees; Amgen, Inc., BioTheryX, Inc., Bristol-Myers Squibb, Celgene, EcoR1 Capital LLC, Genzyme, GSK Biologicals, Janssen Biotech, Karyopharm Therapeutics, Inc., Neoleukin Corporation, Oncopeptides AB, Regeneron Pharmaceuticals, Inc., Sanofi-Aventis, and Takeda P: Consultancy, Honoraria. Shain: AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Amgen Inc: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sanofi Genzyme: Consultancy, Speakers Bureau; GlaxoSmithLine, LLC: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Adaptive Biotechnologies Corporation: Consultancy, Speakers Bureau; Janssen oncology: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Karyopharm Therapeutics Inc.: Honoraria, Research Funding; Novartis Pharmaceuticals Corporation: Consultancy. Cowan: BMS: Research Funding; Secura Bio: Consultancy; GSK: Consultancy; Harpoon: Research Funding; Cellectar: Consultancy; Sanofi: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Nektar: Research Funding. Pei: Janssen: Current Employment, Current equity holder in publicly-traded company. Cortoos: Janssen: Current Employment, Current equity holder in publicly-traded company. Patel: Janssen: Current Employment. Bartlett: Janssen: Current Employment. Vermeulen: Janssen: Current Employment, Current equity holder in publicly-traded company. Lin: Janssen: Current Employment. Richardson: Sanofi: Consultancy; Secura Bio: Consultancy; Regeneron: Consultancy; Karyopharm: Consultancy, Research Funding; Janssen: Consultancy; Protocol Intelligence: Consultancy; Celgene/BMS: Consultancy, Research Funding; Takeda: Consultancy, Research Funding; GlaxoSmithKline: Consultancy; AstraZeneca: Consultancy; Oncopeptides: Consultancy, Research Funding; AbbVie: Consultancy; Jazz Pharmaceuticals: Consultancy, Research Funding. Voorhees: Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Sanofi: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Oncopeptides: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Secura Bio: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; GlaxoSmithKline: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Karyopharm: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. OffLabel Disclosure: The specific regimen combination is not yet approved, but individual components are.

Abstract: e20024 Background: Daratumumab with lenalidomide, bortezomib, and dexamethasone (D-RVd) induction chemotherapy (IC) has recently been shown to improve depth of treatment response for transplant-eligible newly diagnosed multiple myeloma (NDMM) patients (pts) compared to RVd alone. The aim of this real-world data (RWD) retrospective study is to assess the efficacy and depth of response of D-RVd IC compared to RVd in transplant-eligible pts with NDMM. Methods: HealthTree Cure Hub for Multiple Myeloma (PMID: 35271305) an online portal for pts with plasma cell dyscrasias, was used to analyze validated RWD of 59 pts who received D-RVd to 121 pts with similar clinical characteristics but who received RVd at IC. Of the total 180 pts, 84 had completed IC and were at the initiation of maintenance (MT) at the time of this analysis. Patients that progressed prior to reaching MT or whose treatment deviated from the line of therapy (D-RVd/RVd IC, autologous stem cell transplant [ASCT], and MT, with or without consolidation) were also excluded. Response during MT was assessed using IMWG criteria. Results: From the 180 pts reviewed, 98 were excluded, 5 D-RVd and 10 RVD pts progressed before reaching MT, 11 D-RVd and 31 RVd pts deviated from the line of therapy, and 41 pts had not reached the MT phase at the time of the analysis. The remaining 84 pts (18 D-RVd pts and 64 RVd pts) were analyzed. Demographics and clinical characteristics were well-balanced between groups. The median age of both groups was 65 (range, 42-81), and over half were female (51%). The majority of pts (87%) had R-ISS stage I or II, and 45 pts (25%) had high-risk genetics (by mSMART 3.0). The overall response rate (ORR) was significantly higher for the D-RVd group compared to the RVd group at the initiation of MT (100% vs 62%; odds ratio, 22.4; P = 0.03). As assessed prior to the start of MT the depth of response was more favorable with D-RVd, with the odds ratio of achieving a VGPR or better at MT being significantly higher than RVd (89% to 58%; odds ratio (OR), 5.8; P = 0.03), complete response (CR) (78% to 47%; OR, 3.97; P = 0.03), stringent CR (sCR) (22% to 16%; OR, 1.5; P = 0.51), and minimal residual disease (MRD) negativity (17% to 11%; OR, 1.6; P = 0.51). With a median follow-up of 17 months for the D-RVd group (n = 18) and 29 months for the RVd group (n = 64), 0 events of disease progression occurred in the D-RVd group compared to 23 events in the RVd group. Median PFS was not reached in the D-RVd group and a Kaplan-Meier probability indicated a median PFS of 41 months for the RVd group. Conclusions: These data document improved response rate in transplant-eligible NDMM pts who received daratumumab with RVd as an IC therapy. D-RVd also improved PFS with significant differences between the two groups seen at 12 and 18 months. These results add to the accumulating data that the addition of daratumumab with RVd may be the new standard of care for the aforementioned patient population.

Abstract: 2582 Background: The emergence of B-cell maturation antigen (BCMA) targeted therapies in multiple myeloma (MM) has led to improvements in clinical outcomes in patients with heavily pretreated disease. Little is known about patients’ knowledge, decision-making process, and openness to these novel therapies that include chimeric antigen receptor (CAR) T-cell therapy and bispecific antibodies. This study aims to understand patient perspectives on these BCMA-targeted therapies. Methods: This is a cross-sectional survey completed by patients with MM enrolled in HealthTree Cure Hub, an online portal for patients with plasma cell dyscrasias to help navigate their disease. An 18-question survey was developed by the research team, then reviewed and adjusted by HealthTree’s Patient Advocacy Panel and a physician panel. Responses were analyzed descriptively and reported in aggregate. Results: From 10/28/2022 to 1/12/2023, 325 patients with MM participated in the survey (mean age: 66±8 years; 54% female; 90% White; years since diagnosis: 6.6±4.7; lines of therapy: 3.0±2.6). In general, 26% of patients were open to trying a new therapy right away and 43% were open but would like more information on safety and efficacy. BCMA-targeted therapies were well known with 92% of patients having heard about them. Among respondents for each question, 65% were likely or very likely to try a CAR T-cell therapy if offered and 74% were likely or very likely to try a bispecific therapy; while 17% and 13%, respectively, needed more information to decide. The most requested domains of information were efficacy, side effects (SEs), eligibility, and administration process for both CAR T-Cell and bispecific therapies. "How soon can I receive it" was ranked higher for bispecific therapy while "where can I receive it" was ranked higher for CAR T-cell therapy, relatively. The top attributes of therapy profiles were prolonged life, improved quality of life, longer progression-free survival, and tolerable SEs. To receive an effective therapy, the top acceptable trade-offs included frequent monitoring of SEs and initiating a new drug in a hospital setting, while patients were least willing to compromise on caregiver burden. Additionally, the most acceptable SEs were those that were asymptomatic but would need routine monitoring to prevent serious complications, and those that were cosmetic but non-life-threatening. Conclusions: This study found a high level of openness in patients with MM to try BCMA-targeted therapies if offered. Information on efficacy, safety, availability, and eligibility may assist patients on their decision-making. Patients were willing to accept certain trade-offs for a treatment that could be clinically beneficial. Incorporating patients’ goals, values, and preferences alongside clinical factors and other considerations may further optimize treatment decisions and improve patient outcomes.

Abstract: Background: Autologous stem cell transplantation (ASCT) in multiple myeloma (MM) has been shown to improve survival compared to conventional chemotherapy alone. However, the ability to perform ASCT relies, in part, on collecting a sufficient number (#) of CD34+ hematopoietic stem cells (HSCs), typically from peripheral blood. The ideal HSC mobilization regimen would enable collection of optimal #s of HSCs (5-6x10 6 CD34+ cells/kg) within the minimum # of apheresis sessions possible. Yet, despite currently available G-CSF (G) based mobilization regimens and multiple apheresis days, many remain unable to collect optimal #s of HSCs. Motixafortide (M) is a novel CXCR4 inhibitor, with high affinity (IC 50 0.54-4.5 nM) and long receptor occupancy ( & gt;48 hours). Methods: In this prospective, phase 3, double blind, placebo controlled, multicenter trial, 122 patients were randomized (2:1) to receive either M+G or placebo (P)+G for HSC mobilization prior to ASCT for MM. All patients received G (10 mcg/kg) on days 1-5 (and 6-8, if needed). Patients received either M (1.25 mg/kg, subcutaneous injection) or P on day 4 (and 6, if needed). Apheresis began day 5, with the primary (PEP) and secondary (SEP) endpoints of collecting ≥6x10 6 CD34+ cells/kg in up to 2 apheresis days or 1 day, respectively. Apheresis continued on days 6-8 if needed. Total CD34+ cells/kg were analyzed on site to determine if patients mobilized to the goal and all samples were subsequently sent for assessment by central laboratory. Patients that did not collect ≥2x10 6 CD34+ cells/kg by day 8 proceeded to rescue mobilization. The # of CD34+ cells infused was determined independently by each investigator according to local practice (minimum ≥2x10 6 CD34+ cells/kg). Analyses of the PEP/SEPs were performed on an intent-to-treat basis. Results: Demographics between the 2 treatment arms were similar. Mobilization with M+G resulted in 92.5% of patients collecting ≥6x10 6 CD34+ cells/kg within 2 apheresis days vs 26.2% with P+G (Odds Ratio (OR) 53.3, 95% CI 14.12-201.33, p & lt;0.0001). Furthermore, 88.8% of patients with M+G collected ≥6x10 6 CD34+ cells/kg in 1 apheresis day vs 9.5% with P+G (OR 118.0, 95% CI 25.36-549.35, p & lt;0.0001); and 96.3% with M+G collected ≥2x10 6 CD34+ cells/kg within 1 apheresis day vs 64.3% with P+G (OR 18.9, 95% CI 4.47-80.04, p & lt;0.0001). The PEP and SEPs were confirmed as statistically significant by central laboratory (all respective p-values & lt;0.0001). The median # of HSCs mobilized in 1 apheresis day with M+G was 10.80x10 6 CD34+ cells/kg vs 2.14x10 6 CD34+ cells/kg with P+G. The # of cells infused was determined independently by each investigator according to local practice. Median time to neutrophil engraftment was 12 days in both arms (HR 0.94, 95% CI 0.62-1.41, p=0.75). Median time to platelet engraftment was 18 days (range: 17-19) with M+G and 17 days (range: 17-18) with P+G (HR 0.89, 95% CI 0.59-1.34, p=0.57). Graft durability at day 100 post-ASCT was 92.2% in the M+G arm and 91.9% in the P+G arm (OR 1.04, 95% CI 0.2-4.5, p=0.96). Overall, adverse events were reported in 98.8% (Grade 3/4: 68.8%) of patients with M+G vs 95.2% (Grade 3/4: 42.9%) with P+G, with cytopenias in the post-ASCT period prior to engraftment accounting for the majority of Grade 3/4 AEs in both arms, as expected. The most common AEs related to M included: local injection site reactions (any grade: 70.0%, Grade 3/4: 11.3%); and systemic reactions such as pruritis (33.8%), flushing (32.5%) and urticaria (12.5%). Additionally, mobilization with M+G resulted in a 10.5x increase in mean absolute # of CD34+CD45RA-CD123loCD38-CD90+CD49f+ primitive HSCs collected vs P+G (p & lt;0.0001). Multicolor FACS and scRNA sequencing of CD34+ HSCs from both arms will be reported in a separate ASH abstract. Conclusions: A single injection of M on top of G significantly increased the proportion of patients mobilizing ≥6x10 6 CD34+ cells/kg for ASCT (92.5%) vs G (26.2%) in up to 2 apheresis days (p & lt;0.0001), while enabling 88.8% to collect ≥6x10 6 CD34+ cells/kg in just 1 apheresis (p & lt;0.0001, Figure 1A). Despite the higher # of cells mobilized by M+G, the # of CD34+ cells/kg infused was determined independently by each investigator according to local practice with comparable engraftment kinetics and graft durability between the 2 arms. Finally, M+G mobilized 10.5x more immunophenotypically primitive CD34+ HSCs capable of durable multilineage hematopoietic engraftment vs P+G (p & lt;0.0001, Figure 1B). Figure 1 Figure 1. Disclosures Crees: BioLineRx Ltd.: Research Funding. Larson: TORL biotherapeutics: Current holder of individual stocks in a privately-held company; Bioline: Research Funding; Abbvie: Research Funding; BMS: Research Funding; Celgene: Research Funding; GSK: Research Funding; Janssen: Research Funding; Juno: Research Funding; Novartis: Research Funding; Pfizer: Research Funding; Takeda: Research Funding. Illés: Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees; Roche: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees. Stiff: Incyte: Research Funding; Cellectar: Research Funding; Seagen: Research Funding; Gamida Cell: Research Funding; Cellectar: Research Funding; Actinium: Research Funding; Bristol Myers Squibb: Research Funding; BioLineRX: Research Funding; Macrogenics: Research Funding; CRISPR Therapeutics: Consultancy, Honoraria; Amgen: Research Funding; Janssen: Research Funding; Kite, a Gilead Company: Research Funding; Karyopharm: Consultancy, Honoraria; MorphoSys: Consultancy, Honoraria. Sborov: Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; GlaxoSmithKline: Consultancy; Sanofi: Consultancy; SkylineDx: Consultancy. Pereira: Jazz Pharmaceutical: Membership on an entity's Board of Directors or advisory committees. Mikala: Novartis: Consultancy; Takeda: Consultancy; Abbvie: Consultancy; Krka: Consultancy; Janssen: Consultancy; Amgen: Consultancy; Celgene: Consultancy. Holtick: Celgene: Honoraria; Sanofi: Honoraria. Qazilbash: Amgen: Research Funding; Oncopeptides: Other: Advisory Board; Bristol-Myers Squibb: Other: Advisory Board; Biolline: Research Funding; Angiocrine: Research Funding; NexImmune: Research Funding; Janssen: Research Funding. Hardy: American Gene Technologies, International: Membership on an entity's Board of Directors or advisory committees; Kite/Gilead: Membership on an entity's Board of Directors or advisory committees; InCyte: Membership on an entity's Board of Directors or advisory committees. Vainstein: BioLineRx LTD: Current Employment. Sorani: BioLineRx LTD: Current Employment. Gliko-Kabir: BioLineRx Ltd.: Current Employment. Goldstein: BioLineRx Ltd.: Current Employment. Kadosh: BioLineRx Ltd.: Current Employment.

Abstract: Background: CD34+ hematopoietic stem and progenitor cell (HSPC) dose during hematopoietic cell transplantation (HCT) remains one of the most reliable clinical parameters to predict quality of engraftment. A minimum HSPC dose of 2-2.5x10 6 CD34+ cells/kg is considered necessary for reliable engraftment, while optimal doses of 5-6x10 6 CD34+ cells/kg are associated with faster engraftment, as well as fewer transfusions, infections, and antibiotic days. CXCR4 inhibition significantly improves the number (#) of CD34+ HSPCs mobilized for HCT, when added to G-CSF (G). Motixafortide (M), a novel CXCR4 antagonist, is a potent mobilizer of HSPCs recently evaluated in the phase 3, double blind, placebo controlled, multicenter GENESIS Trial as a mobilizing agent prior to autologous HCT (ASCT) in multiple myeloma (MM). Methods: Patients received G (10 mcg/kg) on days 1-5 (and days 6-8, if needed). On day 4 (and day 6, if needed), patients received either M (1.25 mg/kg) or placebo (P). Apheresis began day 5, with up to 4 days of apheresis if needed. The primary and secondary endpoints were collection of ³6x10 6 CD34+ cells/kg in up to 2 days of apheresis or 1 day, respectively. The # of CD34+ cells/kg infused was determined independently by each investigator according to local practice, but a minimum of ³2x10 6 CD34+ cells/kg was required. A post-hoc analysis was performed pooling data from both arms to evaluate time to platelet engraftment (TPE) (≥20x10 9/L without transfusions x7 days) and neutrophil engraftment (TNE) (ANC ≥0.5x10 9/L x3 days) based on total # of CD34+ cells/kg and # of specific CD34+ HSPC subsets infused. CD34+ HSPC immunophenotyping was performed via multicolor fluorescence-activated cell sorting (FACS). TPE/TNE was analyzed using Kaplan-Meier curves and Cox proportional hazards model. Results: 114 MM patients underwent apheresis, ASCT and were evaluable (M+G N=77; P+G N=37). M+G mobilization yielded a median of 10.8x10 6 CD34+ cells/kg collected in 1 apheresis vs 2.3x10 6 CD34+ cells/kg with P+G (p & lt;0.0001). M+G also resulted in mobilization of higher #s of relevant CD34+ HSPC subsets vs P+G, including 5.6 fold more HSCs (CD45RA-CD123loCD38+CD90+CD49f+) (p & lt;0.0001), 3.5 fold more multipotent progenitors (MPPs) and common myeloid progenitors (CMPs) (CD45RA-CD123loCD38+CD90-CD49f+) (p=0.0004) and 5.6 fold more granulocyte and macrophage progenitors (GMPs) (CD45RA+CD123loCD38+/-CD10-) ( & lt;0.0001). The median # of infused HSPCs in both arms was & lt;6x10 6 CD34+ cells/kg (Table 1), with similar TPE of 17-18 days (HR 0.89, 95% CI 0.59-1.34, p=0.57) and TNE of 12 days (HR 0.94, 95% CI 0.62-1.41, p=0.75). However, pooled analysis of all patients (N=114) revealed infusion of ³6x10 6 CD34+ cells/kg was associated with faster median TPE of 16 days vs 18 days with & lt;6x10 6 CD34+ cells/kg (HR 0.63, 95% CI 0.41-0.96, p=0.03) (Figure 1A). Further analysis demonstrated an inverse correlation between increasing CD34+ cells/kg infused and TPE (Pearson r=-0.2789, p=0.0027). In addition, pooled analysis of 36 patients (M+G N=24; P+G N=12) using extended multicolor FACS revealed infusion of higher #s ( & gt;75 th percentile) of combined CD34+ HSC, MPP, CMP and GMP subsets was associated with faster TPE of 12 days vs 19 days with lower #s of these subsets (p=0.003) (Figure 2A). Furthermore, higher #s ( & gt;75 th percentile) of GMPs was individually associated with faster TPE of 13 days vs 19 days with lower GMP cell doses (p=0.0116) (Figure 2C). TNE was not impacted by increasing doses of total CD34+ HSPCs or any specific CD34+ HSPC subset (all p & gt;0.05) (Figures 1B, 2B and 2D). Conclusions: M+G mobilization enabled significantly more CD34+ cells to be collected in 1 apheresis (median 10.8x10 6 CD34+ cells/kg) vs P+G (2.3x10 6 CD34+ cells/kg), as well as 3.5-5.6 fold higher #s of HSCs, MPPs, CMPs and GMPs (all p-values & lt;0.0004). This high # of CD34+ cells/kg mobilized with M+G enables the potential infusion of ≥6x10 6 CD34+ cells/kg and cryopreservation of cells for later use. A dose response was observed with significant correlation between faster TPE and infusion of higher #s of total CD34+ HSPC doses (³6x10 6 CD34+ cells/kg) and combined HSC, MPP, CMP and GMP subsets. Additionally, infusion of higher #s of CD34+ GMP subsets was independently associated with faster TPE, suggesting these more committed progenitors may play a critical role in early engraftment. Figure 1 Figure 1. Disclosures Crees: BioLineRx Ltd.: Research Funding. Retting: BioLineRx Ltd.: Research Funding. Larson: TORL biotherapeutics: Current holder of individual stocks in a privately-held company; Abbvie, Bioline, BMS, Celgene, GSK, Janssen, Juno, Novartis, Pfizer, Takeda: Research Funding. Illes: Novartis, Janssen, Pfizer, Roche: Other: Travel, Accommodations, Expenses; Takeda, Seattle Genetics: Research Funding; Janssen, Celgene, Novartis, Pfizer, Takeda, Roche: Consultancy. Stiff: CRISPR: Consultancy; Gamida-Cell, Atara, Amgen, Incyte, Takeda, Macrogenetics, Eisai: Research Funding. Sborov: SkylineDx: Consultancy; GlaxoSmithKline: Consultancy; Sanofi: Consultancy; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees. Pereira: Jazz Pharmaceutical: Membership on an entity's Board of Directors or advisory committees. Mikala: Abbvie: Consultancy; Amgen: Consultancy; Celgene: Consultancy; Janssen: Consultancy; Krka: Consultancy; Novartis: Consultancy; Takeda: Consultancy. Holtick: Sanofi: Honoraria; Celgene: Honoraria. Qazilbash: Janssen: Research Funding; Oncopeptides: Other: Advisory Board; Biolline: Research Funding; Bristol-Myers Squibb: Other: Advisory Board; NexImmune: Research Funding; Amgen: Research Funding; Angiocrine: Research Funding. Hardy: Kite/Gilead: Membership on an entity's Board of Directors or advisory committees; American Gene Technologies, International: Membership on an entity's Board of Directors or advisory committees; InCyte: Membership on an entity's Board of Directors or advisory committees. Sorani: BioLineRx LTD: Current Employment. Shemesh-Darvish: BioLineRx LTD: Current Employment. Vainstein: BioLineRx LTD: Current Employment; Enlivex: Consultancy. Kadosh: StatExcellence: Current holder of individual stocks in a privately-held company; BioLineRx: Honoraria.