Abstract: Introduction: CD38 is highly and uniformly expressed on myeloma cells (1). Daratumumab is a human anti-CD38 IgG1κ monoclonal antibody that has previously shown a favourable safety profile as a single agent in patients with relapsed and refractory (RR) multiple myeloma (MM) (2). This study further assesses the efficacy of Daratumumab in combination with Dexamethasone in heavily pre-treated myeloma patients that are refractory to Lenalidomide, Pomalidomide, and Bortezomib. Methods: This study is an ongoing, open-label phase II study of Daratumumab in combination with Dexamethasone (NCT02626481). Sixty-four, heavily pretreated Patients were recruited in thirty centres in France and Belgium from November 2015, to receive Daratumumab and Dexamethasone. Daratumumab 16 mg/kg was administered weekly during the first two 28-day cycles, every other week during Cycles three through six, and monthly in Cycle seven and beyond until disease progression or unacceptable toxicity. Patients were all refractory to Lenalidomide (Len), Pomalidomide (Pom) (defined by a progression within 60 days from last drug dosing) and Bortezomib (Bz) (defined by a progression within 6 months from last drug dosing). The primary objective was overall response rate as per the International Myeloma Working Group criteria. A planned safety and efficacy interim analysis was performed after the first 19 patients were enrolled. The last patient was enrolled on the 1stof August 2016. Results: Sixty-four patients were recruited onto the study. The median age (range) at screening was 61 (30-80). The median number (range) of prior lines of therapy was 6 (2-9). Sixty-seven percent of patient had previously received an autologous stem-cell transplant. At the time of screening, 20% of patients (n=13) had a t(4;14) and 12.5% (n=8) a del(17p). Planned interim analysis after the first 19 patients were enrolled did not find any unexpected toxicity. Safety and efficacy results (data cut May 15, 2016) of Daratumumab 16 mg/kg are presented here. No patient discontinued treatment due to Treatment Emergent Adverse Event such as infusion related reactions. Ten (15%) patients discontinued treatment due to disease progression after a median of one-cycle. The most common non-haematological TEAEs included infusion related (IRR, n=5, 8%), and fatigue (n=6, 9.3%). All patients with IRRs recovered and continued to receive treatment. Only six (9.5%) patients experienced hyperthermia. Thrombocytopenia and neutropenia were the most frequently reported grade 3 or 4 TEAE (11 and 5% respectively). Planned interim efficacy assessment showed a response rate (defined as a Partial Response (PR) or greater) in 3/19 patients at the end of the first cycle and 4/19 at the end of the second cycle, and a clinically relevant response (Stable Disease (SD) or greater) at the end of the second cycle for 11 of 19 patients, thus meeting the planed futility criteria and enabling the trial to go forward. As per the 15thof May, among the 40 evaluable patients (that had received at least 2 treatment cycles or progressed within the first) the overall response rate (3) was 25%, with eight (20%) partial responses (PR) and two (5%) very good partial responses (VGPRs) after a median of two cycles (range 1-5). An additional seven patients (17.5%) obtained a Minimal Response (MR) according to the EBMT criteria (4). This is consistent with prior results. Updated results will be presented at the time of ASH. Conclusions: Daratumumab in combination with Dexamethasone is a safe treatment option with a favourable benefit/risk profile for the treatment of triple relapsed or refractory (Len, Pom and Bz) myeloma patients. 1. Stevenson GT. CD38 as a Therapeutic Target. Mol Med. 2006;12(11-12):345-6. 2. Lokhorst HM, Plesner T, Laubach JP, Nahi H, Gimsing P, Hansson M, et al. Targeting CD38 with Daratumumab Monotherapy in Multiple Myeloma. N Engl J Med. 2015 Sep 24;373(13):1207-19. 3. Kyle R, Rajkumar S. Criteria for diagnosis, staging, risk stratification and response assessment of multiple myeloma. Leuk Off J Leuk Soc Am Leuk Res Fund UK. 2009 Jan;23(1):3-9. 4. Bladé J,et al. Criteria for evaluating disease response and progression in patients with multiple myeloma treated by high-dose therapy and haemopoietic stem cell transplantation. Myeloma Subcommittee of the EBMT. Br J Haematol. 1998 Sep;102(5):1115-23. Disclosures Boyle: Novartis: Honoraria; Pfizer: Honoraria; Takeda: Honoraria; Janssen: Honoraria. Leleu:Novartis: Honoraria; LeoPharma: Honoraria; Pierre Fabre: Honoraria; Amgen: Honoraria; Bristol-Myers Squibb: Honoraria; Takeda: Honoraria; Celgene: Honoraria; Janssen: Honoraria; TEVA: Membership on an entity's Board of Directors or advisory committees. Hulin:Amgen: Honoraria; Janssen: Honoraria; Bristol: Honoraria; celgene: Honoraria; takeda: Honoraria. Moreau:Takeda: Honoraria; Janssen: Honoraria, Speakers Bureau; Celgene: Honoraria; Novartis: Honoraria; Amgen: Honoraria; Bristol-Myers Squibb: Honoraria. Fohrer:amgen: Consultancy; celgne: Consultancy. Decaux:SIEMENS: Honoraria, Other: supply of free light chain assays , Research Funding; The Binding Site: Other: supply of free light chain assays , Research Funding. Avet-Loiseau:celgene: Consultancy; amgen: Consultancy; janssen: Consultancy; sanofi: Consultancy. Attal:celgene: Consultancy, Research Funding; amgen: Consultancy, Research Funding; janssen: Consultancy, Research Funding; sanofi: Consultancy. Facon:Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: travel and expense, Speakers Bureau.

Abstract: Belantamab mafodotin (BM) is an anti-BCMA antibody-drug conjugate (GSK2857916) that represents an alternative option in multiple myeloma. We sought to assess the efficacy and safety of BM in a real-world setting in patients who benefited from an early access program. We conducted an observational, retrospective, multicenter study. Eligibility criteria were treatment of relapsed or refractory multiple myeloma (RRMM) in monotherapy in adult patients who have received at least three lines of therapy previously, including at least one immunomodulatory agent (IMiD), a proteasome inhibitor (PI) and an anti-CD38 monoclonal antibody, and whose disease progressed during the last treatment period. The primary endpoint of the study is to assess the overall survival (OS). Between November 2019 and December 2020, 106 patients were treated with BM; 97 were eligible for the efficacy evaluation and 104 for safety. The median age was 66 (range, 37–82) years. High-risk cytogenetics were identified in 40.9% of patients. Fifty-five (56.7%) patients were triple-class refractory and 11 (11.3%) were penta-class refractory. The median number of prior lines of treatment was five (range, 3–12). The median number of BM cycles administered was three (range, 1–22). The overall response rate at best response was 38.1% (37/97). The median OS was 9.3 months (95% confidence interval [CI]: 5.9-15.3), and median progression-free survival was 3.5 months (95% CI: 1.9-4.7). The median duration of response was 9 months (range, 4.65-10.4). Treatment was delayed for 55 (52.9%) patients including 36.5% for treatment-related toxicity. Ophthalmic adverse events, mainly grade ≤2, were the most common toxicity (48%). The occurrence of keratopathy was 37.5%. Overall, our data are concordant with the results from DREAMM-2 in terms of efficacy and safety on a non-biased population.

Abstract: High-dose melphalan (HDM) and transplantation are recommended for eligible patients with multiple myeloma. No other conditioning regimen has proven to be more effective and/or safer. We previously reported in a phase 2 study that bortezomib can safely and effectively be combined with HDM (Bor-HDM), with a 32% complete response (CR) rate after transplantation. These data supported a randomized phase 3 trial. Randomization was stratified according to risk and response to induction: 300 patients were enrolled, and 154 were allocated to the experimental arm (ie, arm A) with bortezomib (1 mg/m2 intravenously [IV]) on days −6, –3, +1, and +4 and melphalan (200 mg/m2 IV) on day –2. The control arm (ie, arm B) consisted of HDM alone (200 mg/m2 IV). There were no differences in stringent CR + CR rates at day 60 posttransplant (primary end point): 22.1% in arm A vs 20.5% in arm B (P = .844). There were also no differences in undetectable minimum residual disease rates: 41.3% vs 39.4% (P = .864). Median progression-free survival was 34.0 months for arm A vs 29.6 months for arm B (adjusted HR, 0.82; 95% CI, 0.61-1.13; P = .244). The estimated 3-year overall survival was 89.5% in both arms (hazard ratio, 1.28; 95% CI, 0.62-2.64; P = .374). Sixty-nine serious adverse events occurred in 18.7% of Bor-HDM–treated patients (vs 13.1% in HDM-treated patients). The proportion of grade 3/4 AEs was similar within the 2 groups (72.0% vs 73.1%), mainly (as expected) blood and gastrointestinal disorders; 4% of patients reported grade 3/4 or painful peripheral neuropathy in arm A (vs 1.5% in arm B). In this randomized phase 3 study, a conditioning regimen with Bor-HDM did not improve efficacy end points or outcomes compared with HDM alone. The original trial was registered at www.clinicaltrials.gov as #NCT02197221.

Abstract: Abstract 3096 Background. Several studies have demonstrated the impact of VTd on response rates and PFS either as induction or consolidation regimen. However there are limitations to these studies, especially that no data is available regarding the role of VTd consolidation in the context of bortezomib-triple based VTd induction regimen followed by a single auto. At completion of therapy, the response rate (ORR, PR and better) was 89%, VGPR+CR rate 74%, CR rate 29%, relapse rate and median PFS was 53% and 26 months (median F-up 32 months) in the VTd arm of the phase 3 IFM2007-02 trial conducted for newly diagnosed MM (Moreau et al, Blood 2012). In this study, only a minority of patients had received a consolidation or maintenance. On the other hand, Cavo et al. (Blood 2012) reported 97.5%, 92%, 61%, 39% 3-year progression and 62% estimated 5-year PFS (F-up 43 months) respectively in the VTd arm. VTd was given as induction before and consolidation after double auto in this upfront GIMEMA phase 3 trial (Cavo et al, Lancet 2010). We aimed to assess the efficacy and safety of VTd as consolidation therapy in the context of VTd as induction regimen followed by a single auto (VTd-auto-VTd regimen). Method. This study has included a first group of 121 newly diagnosed MM from 2009 to 2011 across 9 IFM centers. Patients were to be eligible for auto upfront, aged less than 65 and treated with VTd-auto-VTd regimen. The second cohort included MM treated with VTd-auto without consolidation from the IFM2007-02 trial (n=76). A third cohort comprised MM that received upfront a triplet Vd-based combination induction (VCd, VRd) -auto without consolidation (n = 40). Results. In the whole study, the median age was 56 years, the sex ratio was 1,49, 50% had ISS 2 and 3, 22% had adverse FISH [t(4;14); del17p] (similar in the 3 groups). Overall, the ORR was identical in the 3 cohorts at completion of therapy, 104 (86%), 72 (94%) and 32 (80%) for the cohort 1 to 3, respectively. Nevertheless, the CR rate was significantly greater in patients that received a consolidation (cohort 1), as compared to the cohorts 2 and 3 that did not receive any consolidation, 59 (53%) vs. 26 (34%) and 13 (32.5%), respectively (p=0.0001). Interestingly, the CR rates were identical at the end of the induction in the 3 cohorts, 13%, 15% and 22.5%, respectively. With a median follow-up of 25 months, the incidence rate of relapse was significantly greater in the cohort 2 and 3 versus 1, further demonstrating the importance of the consolidation, 25 (21%), 42 (55%) and 13 (32.5%) patients (p=0.0001), respectively; and 9 (8%), 6 (8%) and 8 (20%) had died in cohorts 1 to 3 (p=0.07). The median (95%CI) PFS was not reached in cohort 1, and was 32 (28;36) months and 30 (26;33) months in cohort 2 and 3, respectively. Importantly, 54.5%, 32% and 32% of patients were free of relapse at 32 months in the 3 cohorts, respectively. Similar data were obtained for TTP. The median (95%CI) OS was not significantly different in cohorts 1 to 3, although not reached for the first 2 cohorts and 38 (33;43) months for the 3rdcohort. The 3-year survival was 84%, 91% and 76%, respectively (p=ns). A longer follow up will certainly demonstrate greater survival end points benefit in favor for consolidation. The safety profile of the cohort that contained a consolidation was superimposable to that of the remaining 2 cohorts without consolidation. The incidence rate of hematological EIs of grade 3 and 4 was 4%, 6% and 8% in the 3 cohorts (p=ns), respectively. The incidence rate of neuropathy grade 1–2 and 3–4 was 5% and 2% in the cohort 1 with consolidation, but only 1% occurred during the consolidation. This data compares favorably to the 3% reported in the cohort 2 (Moreau et al. Blood 2012). We have also observed 9 (9%) thromboembolic events (TE), 8 of venous type and 1 arterial. None of them happened during the consolidation, and again, this incidence rate if superimposable to that reported in the IFM2007-02 vTd cohort. Conclusion. This study showed an impressive increase in CR rate in relation to the consolidation that translated into a lower relapse rate. This study also demonstrated that the VTd regimen, used both as induction and consolidation, in the context of a single auto upfront in MM, significantly contributed to improve clinical outcomes with an acceptable toxicity profile. VTd-auto-VTd compared very favorably to the other upfront protocols, and may become in the near future a standard of care in newly diagnosed patients with Myeloma. Disclosures: Leleu: Celgene: Honoraria, Research Funding, Speakers Bureau; Janssen: Honoraria, Research Funding, Speakers Bureau; Novartis: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Sanofi: Honoraria; Onyx: Honoraria, Speakers Bureau; LeoPharma: Honoraria, Speakers Bureau. Off Label Use: Pomalidomide. Roussel:celgene: Honoraria; janssen: Honoraria. Facon:onyx: Membership on an entity's Board of Directors or advisory committees; celgene: Membership on an entity's Board of Directors or advisory committees; janssen: Membership on an entity's Board of Directors or advisory committees; millenium: Membership on an entity's Board of Directors or advisory committees. Attal:celgene: Membership on an entity's Board of Directors or advisory committees; janssen: Membership on an entity's Board of Directors or advisory committees.

Abstract: Cytogenetic abnormalities (CAs) are known to be the preponderant prognostic factor in multiple myeloma. Our team has recently developed a prognostic score based on 6 CAs, with which del(1p32) appears to be the second worst abnormality after del(17p). This study aimed to confirm the adverse effect of 1p32 deletion in patients with newly diagnosed multiple myeloma (NDMM). Among 2551 patients with newly diagnosed multiple myeloma, 11% were harboring del(1p32). Their overall survival (OS) was significantly inferior compared with patients without del(1p32) (median OS: 49 months vs 124 months). Likewise, progression-free survival was significantly shorter. More importantly, biallelic del(1p32) conferred a dramatically poorer prognosis than a monoallelic del(1p32) (median OS: 25 months vs 60 months). As expected, the OS of patients with del(1p32) significantly decreased when this abnormality was associated with other high-risk CAs [del(17p), t(4;14), or gain(1q)]. In the multivariate analysis, del(1p32) appeared as a negative prognostic factor; after adjustment for age and treatment, the risk of progression was 1.3 times higher among patients harboring del(1p32), and the risk of death was 1.9 times higher. At the dawn of risk-adapted treatment strategies, we have confirmed the adverse effect of del(1p32) in multiple myeloma and the relevance of its assessment at diagnosis.

Abstract: In myeloma patients, trisomy 3 improved time to progression and trisomies 3 and/or 5 improved overall survival. In contrast, trisomy 21 significantly worsened overall survival.

Abstract: MRD using NGS-identified patients with an excellent outcome in multiple myeloma. MRD should be assessed in every prospective trial, and is a candidate to become a primary end point.

Abstract: The three-drug combination of lenalidomide, bortezomib, and dexamethasone (RVD) has shown significant efficacy in multiple myeloma (MM). The Intergroupe Francophone du Myélome (IFM) decided to evaluate RVD induction and consolidation therapies in a sequential intensive strategy for previously untreated transplantation-eligible patients with MM. Patients and Methods In this phase II study, 31 symptomatic patients age 〈 65 years were enrolled to receive three RVD induction cycles followed by cyclophosphamide harvest and transplantation. Patients subsequently received two RVD consolidation cycles and 1-year lenalidomide maintenance. Results Very good partial response rate or better at the completion of induction, transplantation, and consolidation therapy was 58%, 70%, and 87%, respectively. Maintenance upgraded responses in 27% of patients. Overall, 58% of patients achieved complete response, and 68% were minimal residual disease (MRD) negative by flow cytometry. The most common toxicities with RVD were neurologic and hematologic, including grade 1 to 2 sensory neuropathy (55%), grade 3 to 4 neutropenia (35%), and thrombocytopenia (13%). Two basal cell carcinomas in the same patient and one case of breast cancer were observed. There was no treatment-related mortality. With a median follow-up of 39 months, estimated 3-year progression-free and overall survival were 77% and 100%, respectively. None of the patients who achieved MRD negativity relapsed. Conclusion The transplantation program with RVD induction and consolidation followed by lenalidomide maintenance produced high-quality responses and showed favorable tolerability in patients with newly diagnosed MM. Overall, 68% of patients achieved MRD negativity; none of these patients relapsed. This program is being evaluated in the ongoing IFM/Dana-Farber Cancer Institute 2009 phase III study.