Sustained Minimal Residual Disease Research Articles

Trial in Progress: A Phase 2 Study of Linvoseltamab for the Treatment of High-Risk Smoldering Multiple Myeloma (LINKER-SMM1)

Background and Significance Smoldering multiple myeloma (SMM) is an asymptomatic clonal plasma cell disorder that precedes the development of multiple myeloma (MM). Traditionally, patients with SMM have undergone observation until progression to MM, but this paradigm can result in poor outcomes for some patients. Phase 3 clinical trials have demonstrated that early treatment with lenalidomide with or without dexamethasone can delay the development of end-organ damage and improve overall survival among SMM patients with high-risk features. Linvoseltamab (REGN5458) is a fully human B-cell maturation antigen (BCMA)×CD3 bispecific antibody that targets BCMA on plasma cells and CD3 on T cells, resulting in targeted T-cell-mediated cytotoxicity. In the Phase 1/2 LINKER-MM1 study, linvoseltamab alone induced deep and durable responses with a generally manageable safety profile in patients with relapsed/refractory MM (Lee et al. EHA. 2023). These data highlight the potential of novel immunotherapies with promising single-agent activity to be attractive therapeutics for early intervention to prevent progression to MM. Study Design and Methods LINKER-SMM1 is an open-label, Phase 2 study (NCT05955508) designed to evaluate the safety and efficacy of linvoseltamab monotherapy in adult participants with SMM who are at a high risk of progression to MM. High-risk criteria include having both ≥95% clonal plasma cells in the bone marrow (BM) and immunoparesis and/or ≥2 of the following: serum M-protein >2 g/dL, free light chain ratio >20, and BM plasma cells >20%. Participants must have a confirmed diagnosis of SMM within 5 years of enrollment, Eastern Cooperative Oncology Group performance status ≤1, and adequate organ function to be eligible. Participants will be excluded from enrollment if they have myeloma-defining events, uncontrolled infection, history of allogeneic stem cell transplantation, or received prior treatment for SMM. The study will take place at approximately 15 sites in Spain and will include two parts: Part 1 (safety run-in) to evaluate the preliminary safety and tolerability of linvoseltamab and Part 2 (expansion) to evaluate the clinical activity of the selected dosing regimen. In Part 1, at least 6 participants will receive linvoseltamab starting with a step-up schedule before reaching the full dose. All subsequent treatment with full-dose linvoseltamab will be given over 28-day cycles until completion of 24 cycles or occurrence of a protocol-defined reason for discontinuation. Assuming that initial safety is shown to be acceptable, an additional 34 participants will be enrolled in Part 2 according to the dosing regimen established in Part 1. Post-treatment safety monitoring will continue for up to 90 days after the last dose of linvoseltamab, and participants with an ongoing response will continue routine efficacy assessments until confirmed biochemical progression, start of non-protocol cancer therapy, or death. Long-term follow-up will continue for up to 5 years after the last dose of linvoseltamab. The primary endpoints in Part 1 are frequency of adverse events (AEs) of special interest, including grade ≥2 cytokine release syndrome and immune effector cell-associated neurotoxicity syndrome, and frequency and severity of treatment-emergent AEs. In Part 2, the primary endpoints are complete response (assessed by International Myeloma Working Group criteria) and minimal residual disease (MRD) negativity (10 -5 sensitivity) after 12 and 24 months of treatment. Secondary endpoints include cumulative safety, overall response rate, duration of response, sustained MRD negativity, biochemical and clinical progression-free survival (PFS), time to myeloma-defining event, time to initiation of first-line treatment for MM, and overall survival as well as immunogenicity and serum concentration of linvoseltamab over time. Exploratory endpoints include PFS after the start of first-line treatment for MM, adequacy of stem cell collection, patient-reported outcomes, and various biomarker changes. As this is a proof-of-concept study, results will be analyzed using descriptive statistics and no formal hypothesis testing is planned. Study accrual is planned to begin in Q4 2023.

The Phase 2 CARTITUDE-2 Trial: Updated Efficacy and Safety of Ciltacabtagene Autoleucel in Patients with Multiple Myeloma and 1-3 Prior Lines of Therapy (Cohort A) and with Early Relapse after First Line Treatment (Cohort B)

Introduction: CARTITUDE-2 (NCT04133636) is a phase 2, multicohort study evaluating the safety and efficacy of ciltacabtagene autoleucel (cilta-cel), an anti-BCMA chimeric antigen receptor (CAR)-T cell therapy, in various populations of patients with multiple myeloma (MM). We previously reported 17-month median follow-up results from cohort A (1-3 prior lines of therapy [LOT] and lenalidomide [len]-refractory) and 18-month median follow-up results from cohort B (early relapse: ≤12 months after either autologous stem cell transplant [ASCT] or start of initial anti-myeloma treatment, if not transplanted). Cilta-cel is also under evaluation in patients with len-refractory MM after 1-3 LOT in the phase 3 CARTITUDE-4 study, which showed cilta-cel significantly prolonged progression-free survival (PFS) vs standard of care (HR, 0.26) at a median follow-up of 16 months. Here, we present updated efficacy and safety data from CARTITUDE-2 cohorts A and B, both with a median follow-up of ~29 months. Methods: Patients in cohorts A and B, all naive to CAR-T and/or anti-BCMA therapies, received a single cilta-cel infusion (target dose 0.75×10 6 CAR+ viable T cells/kg) 5-7 days after lymphodepletion. In both cohorts, the primary endpoint was minimal residual disease (MRD)-negativity (10 -5 threshold, by next-generation sequencing or next-generation flow cytometry). Management strategies were implemented after the phase 1b/2 CARTITUDE-1 study to reduce risk of movement and neurocognitive treatment-emergent adverse events (MNTs). Results: As of April 2023, 20 patients in cohort A had received cilta-cel (median follow-up, 29.9 months; 35% with high-risk cytogenetics; median 2 prior LOT; 95% refractory to last LOT; 40% triple-class refractory; 85% with prior ASCT). At the same data cut-off, 19 patients in cohort B hadreceived cilta-cel (median follow-up, 27.9 months; 16% with high-risk cytogenetics; 79% refractory to last LOT; 16% triple-class refractory; 79% with prior ASCT). All (100%) 17 MRD-evaluable patients in cohort A and 14 (93%) of 15 MRD-evaluable patients in cohort B achieved MRD negativity (10 -5 threshold). Eight (40%) of 20 patients in cohort A and 10 (53%) of 19 patients in cohort B sustained MRD negativity at 10 -5 for ≥6 months (Table 1). In the 20 patients in cohort A and 19 in cohort B, cilta-cel led to overall response rates of 95% (complete response or better [≥CR], 90%) and 100% (≥CR, 90%), respectively. Median PFS was not reached in either cohort, and 24-month PFS rates were 75% in cohort A and 73% in cohort B; respective 24-month overall survival rates were 75% and 84%. In cohort A, hematologic treatment-emergent adverse events (TEAEs) occurring between 17.1- and 29.9-month median follow-up included maximum grade (gr) 3/4 leukopenia in 1 patient (all gr,12 total; 60%), maximum gr 3/4 lymphopenia in 2 patients (all gr,16 total; 80%), and maximum gr 3/4 thrombocytopenia in 1 patient (all gr,16 total; 80%). In cohort B, no new patients reported hematologic TEAEs between 18.0- and 27.9-month median follow-up (Table 2). In cohort A, no new patients had CAR-T cell neurotoxicity, and no patients had a second primary malignancy (SPM). In cohort B, no new patients had MNTs, but other neurotoxicity (gr 2 sensory loss) occurred in 1 additional patient (all gr, 5 total; 26%) and resolved; and SPM (gr 4 choroid melanoma) occurred in 1 additional patient (all gr, 2 total; 11%). One new death (total 5) occurred in cohort A on day 666 due to progressive disease, and 1 new death (total 4) occurred in cohort B on day 749 due to cardiac arrest (not treatment related). Conclusions: These longer-term follow-up data show that patients treated with cilta-cel in earlier LOT, both those with len-refractory MM after 1-3 LOT (cohort A) and those with early relapse (cohort B), experienced deep and durable responses. No new CAR-T-related safety signals, except for 1 additional CAR-T cell neurotoxicity in cohort B, were reported. Cohort A provides insight into potential longer-term survival outcomes that may be expected in the phase 3 CARTITUDE-4 trial, which enrolled the same patient population but has shorter follow-up thus far. The long-term cohort B data highlight the durable efficacy of cilta-cel in patients who had early relapse; this is a functionally high-risk population for whom standard risk factors, including a high-risk cytogenetic profile, may not predict risk of relapse and for whom there is significant unmet need.

Sequential T-Cell Engagement for Myeloma (“STEM”) Trial: A Phase 2 Study of Cevostamab Consolidation Following BCMA CAR T Cell Therapy

Background and significance: The BCMA-targeted CAR T products idecabtagene vicleucel (ide-cel) and ciltacabtagene autoleucel (cilta-cel) are currently approved for relapsed/refractory multiple myeloma (RRMM) patients with ≥4 prior lines of therapy, including an IMID, proteasome inhibitor, and CD38 antibody. However, despite unprecedented response rates, CAR T cells are not curative in these late-line patients, even for those in complete remission. Mechanisms of resistance may include lack of persistence or poor function of persisting CAR T cells, as well as BCMA-low or -negative residual tumor cells that serve as a reservoir for relapse. FcRH5 is another MM cell surface antigen, with expression independent of BCMA. Cevostamab is an FcRH5-targeted, T cell-engaging bispecific antibody (bsAb) with demonstrated activity in RRMM, including in patients with prior BCMA-directed therapies (Trudel et al, ASH 2021, #157). We hypothesize that consolidating BCMA CAR T cell therapy with a bsAb targeting a different antigen may re-invigorate persisting CAR+ T cells against residual BCMA+ tumor cells, while also activating endogenous T cells against FcRH5+, BCMA-low/negative tumor cells, ultimately improving rates of sustained minimal residual disease (MRD)-negativity and durability of response. Study design and methods: This is a single-institution, investigator-initiated study (NCT05801939) sponsored by the University of Pennsylvania, with funding support from Genentech. Targeted population are patients with RRMM who have received a commercially available CAR T cell product (ide-cel or cilta-cel) according to the FDA label, within the past 8 weeks, with stable disease or better. Major inclusion criteria include absolute neutrophil count ≥ 1, hemoglobin ≥ 7, platelets ≥ 50, and creatinine clearance ≥ 30 ml/min. Major exclusion criteria include prior cytokine release syndrome or ICANS ≥ grade 3, or any grade hemophagocytic lymphohistiocytosis (HLH) or Parkinsonism, or any active infection. The study schema is shown in Figure 1. Cevostamab is initiated 8-10 weeks after CAR T cell infusion. This timepoint was chosen to allow recovery from acute CAR T cell-related toxicities, but while CAR T cells may still be detectable in circulation. Cevostamab is given at a step-up dose of 3.6mg intravenously (IV) on Cycle 1, Day 1 (C1D1), followed by full dose of 160mg IV on C1D8. Subjects are hospitalized for 48 hours after each C1 dose to monitor for CRS and ICANS. They then continue cevostamab every 3 weeks for total of 8 cycles. If they are in an MRD-negative complete response (CR) after 8 cycles (Adaptive Clonoseq assay, at 10e-5 sensitivity), they stop therapy and are observed. If not, or if bone marrow results are indeterminate, they get another 8 cycles of cevostamab, then stop and are observed. The primary endpoint is frequency of MRD-negative CR at 12 months post-CAR T cell therapy. Assuming a roughly equal proportion of patients enrolling after ide-cel and cilta-cel, the null hypothesis is that the true MRD-negative CR rate at 12 months is 35%. Twenty-six evaluable subjects will be accrued in a single-stage design. The null hypothesis will be rejected if 14 or more subjects meet the primary endpoint. This design yields a one-sided type I error rate of 0.05 and power of 0.84 for an exact test when the true 12-month MRD-negative CR rate is 60%. Secondary endpoints include feasibility, safety/tolerability, and other efficacy measures (overall and CR rates, PFS, OS). Exploratory endpoints include 1) impact of cevostamab on pre- and post-therapy frequency and phenotype of both CAR+ and CAR-negative T cells in blood and marrow, assessed by multiparameter flow cytometry; 2) pre- and post-therapy expression of BCMA and FcRH5 on myeloma cells (when available), serum concentrations of soluble BCMA and FcRH5, and relationship of these factors to clinical outcome measures, and 3) pre- and post-therapy genotypic and phenotypic make-up of bone marrow microenvironment, assessed by single cell RNA sequencing (scRNAseq) and multiparameter flow cytometry, and relationship of these factors to clinical outcome measures. Conclusions: This phase 2 study is exploring the efficacy, safety, and feasibility of cevostamab consolidation following BCMA-directed CAR T cell therapy for RRMM, with the goal of sequential T cell engagement against 2 different antigens to eliminate residual disease. Accrual started in July 2023.

Immunophenotypic correlates of sustained MRD negativity in patients with multiple myeloma

The role of the immune microenvironment in maintaining disease remission in patients with multiple myeloma (MM) is not well understood. In this study, we comprehensively profile the immune system in patients with newly diagnosed MM receiving continuous lenalidomide maintenance therapy with the aim of discovering correlates of long-term treatment response. Leveraging single-cell RNA sequencing and T cell receptor β sequencing of the peripheral blood and CyTOF mass cytometry of the bone marrow, we longitudinally characterize the immune landscape in 23 patients before and one year after lenalidomide exposure. We compare patients achieving sustained minimal residual disease (MRD) negativity to patients who never achieved or were unable to maintain MRD negativity. We observe that the composition of the immune microenvironment in both the blood and the marrow varied substantially according to both MRD negative status and history of autologous stem cell transplant, supporting the hypothesis that the immune microenvironment influences the depth and duration of treatment response.

FIVE‐YEAR UPDATE OF THE FIRST‐LINE IMCL‐2015 GELTAMO STUDY. PROLONGED MOLECULAR AND CLINICAL RESPONSES WERE OBSERVED AFTER MRD‐DRIVEN IBRUTINIB DISCONTINUATION

Introduction: A frontline tailored treatment for indolent clinical forms of mantle cell lymphoma (MCL) with ibrutinib in combination with rituximab was evaluated. A high rate of complete remissions (CR) with undetectable minimal residual disease (MRD) was reported, with predictable toxicity (Giné, JCO 2022). We herein present an updated analysis focusing in the data of treatment discontinuation. Methods: This was an open-label, phase II trial conducted in 14 Spanish GELTAMO sites (NCT02682641). Centralized histology, PET-CT review, MRD studies (qPCR and NGS in peripheral blood) and biological studies were conducted. Previously untreated MCL patients with indolent clinical forms were eligible according to the following criteria: no symptoms attributable to MCL, ECOG 0–1, stable disease without therapy need for at least 3 months, non-blastoid variants, Ki-67 <30% and largest tumor diameter ≤3 cm. Both leukemic non-nodal and nodal forms were acceptable. Patients received ibrutinib 560 mg daily and a total of 8 doses of rituximab 375 mg/m2 (4 weekly doses during the first 28-day cycle, followed by day 1 of cycles 3, 5, 7 and 9). Ibrutinib could be discontinued after 2 years of treatment in case of sustained undetectable MRD. Results: Fifty patients (Male 66%; median age 65 years) were enrolled in the study (June 2016 to December 2019, data cut-off 18 October 2022, median follow-up 54 months and next cut-off is planned in March 2023). The overall response (OR) and CR rates at 12 months of treatment were 84% and 80%, respectively (including 4 early discontinuations). Undetectable MRD was reached in 40 (87%) of 46 evaluable cases (sensitivity 10−5). After 24 months, 42 of 44 patients were in response, with OR and CR rates of 86% and 84%, respectively. Undetectable MRD was observed in 35 (80%) of 44 cases. Thirty-two patients discontinued ibrutinib as per protocol (64% of initial series). Twelve patients continued on ibrutinib. Median time on ibrutinib treatment was 29 months (1.7–51+ months). The median duration of undetectable MRD, achieved in 41 cases, was 60 months (95% CI: 29–92), and has not been reached in the 32 cases that stopped ibrutinib as per protocol. Six patients progressed from the disease between 12 and 72 months of follow-up and three of them eventually died of disease progression. Overall, PFS and OS at 48 months were 86% (95% CI: 75–96) and 88% (95% CI: 79–98), respectively. At current follow-up, 6 patients remain on treatment, and up to 13 patients discontinued ibrutinib because of adverse events, including 7 associated to ibrutinib with a hemorrhagic cardiac tamponade being the most severe. Five secondary neoplasms in 4 patients have been reported. Whole-genome sequencing of paired tumor/normal samples from 34 patients was obtained and will be presented. The research was funded by: The funding for the IMCL-2015 was obtained through unrestricted Janssen Clinical Investigator-Initiated Study (IIS) Research Support Keywords: aggressive B-cell non-Hodgkin lymphoma, molecular targeted therapies Conflicts of interests pertinent to the abstract E. Giné Consultant or advisory role: Gilead, Milteny Honoraria: Janssen, Genmab, Gilead Research funding: Janssen Educational grants: Janssen A. Medina-Herrera Research funding: Janssen Educational grants: Invivoscribe F. de la Cruz Honoraria: Roche, Takeda, Eusa Pharma, Abbvie, Janssen, Beigene, Kiowa Kirin, Astrazeneca and Gilead J. López Jiménez Honoraria: Roche, Abbvie, Janssen and Gilead Research funding: Roche Educational grants: Gilead, Janssen, Abbvie A. Martín García- Sancho Consultant or advisory role: Roche, Celgene/BMS, Morphosys, Kyowa Kirin, Clinigen, Eusa Pharma, Novartis, Gilead, Servier, Incyte Honoraria: Roche, Celgene, Janssen, Servier, Gilead Research funding: Janssen Educational grants: Roche, Servier, Celgene, Janssen, KernPharma M. J. Terol Research funding: Gilead Educational grants: Janssen, Gilead/Kite, Roche, Abbvie A. de la Fuente Honoraria: Abbvie, Astellas Pharma, BMS, incite, JazzPharma, Novartis, Roche and Pfizer Research funding: Janssen, Novartis Educational grants: Abbvie, Astellas Pharma, BMS, Incyte, Janssen, JazzPharma, Mundipharma, Roche, Pfizer A. Marín Niebla Consultant or advisory role: Janssen, Gilead, Kiowa Kirin, Takeda, Beigene Honoraria: Gilead/Kite, Janssen, Genmab Educational grants: Takeda, Janssen, Kiowa Kirin T. J. González López Honoraria: Novartis, Amgen, Sobi, Grifols and Mome Research funding: Novartis, Amgen X. Setoain Honoraria: Roche, Gilead, General Electric Educational grants: General Electric, Takeda R. García Sanz Honoraria: Janssen, Beigene Research funding: Janssen A. López Guillermo Consultant or advisory role: Roche, Gilead/Kite, Celgene, Novartis, Janssen, Abbie, Spectrum Honoraria: Roche, Celgene, Gilead/Kite Research funding: Roche, Celgene, Gilead

Prospective evaluation of minimal residual disease in the phase II FORTE trial: a head-to-head comparison between multiparameter flow cytometry and next-generation sequencing.

Limited data are available on the concordance between multiparameter flow cytometry (MFC) and next-generation sequencing (NGS) for minimal residual disease (MRD) detection in a large trial for multiple myeloma (MM) patients. MRD was explored in the FORTE trial for transplant-eligible MM patients randomised to three carfilzomib-based induction-intensification-consolidation treatments and carfilzomib-lenalidomide (KR) vs R maintenance. MRD was assessed by 8-colour 2nd-generation flow cytometry in patients with ≥very good partial response before maintenance. NGS was performed in case of suspected complete response (CR) in a correlative subanalysis. Biological/prognostic concordance between MFC and NGS, conversion to MRD negativity during maintenance, and 1-year/2-year sustained MRD negativity were explored. Between September 28, 2015 and December 22, 2021, 2020 samples were available for MFC and 728 for the simultaneous MFC/NGS correlation in the "suspected CR population". Median follow-up was 62 months. Biological agreement was 87% at the 10-5 and 83% at the 10-6 cut-offs. A remarkable prognostic concordance was observed: hazard ratios in MFC-MRD and NGS-MRD-negative vs -positive patients were 0.29 and 0.27 for progression-free survival (PFS) and 0.35 and 0.31 for overall survival, respectively (p<0.05). During maintenance, 4-year PFS was 91% and 97% in 1-year sustained MFC-MRD-negative and NGS-MRD-negative patients (10-5), respectively, and 99% and 97% in 2-year sustained MFC-MRD-negative and NGS-MRD-negative patients, regardless of treatment received. The conversion rate from pre-maintenance MRD positivity to negativity during maintenance was significantly higher with KR vs R both by MFC (46% vs 30%, p=0.046) and NGS (56% vs 30%, p=0.046). The significant biological/clinical concordance between MFC and NGS at the same sensitivity suggests their possible use in the evaluation of one of the currently strongest predictors of outcome. Amgen, Celgene/Bristol Myers Squibb, Multiple Myeloma Research Foundation.

CARTITUDE-1 final results: Phase 1b/2 study of ciltacabtagene autoleucel in heavily pretreated patients with relapsed/refractory multiple myeloma.

8009 Background: Heavily pretreated patients (pts) with relapsed/refractory multiple myeloma (RRMM) treated with standard of care therapy have median overall survival (OS) of ~12 months (mo). In the single-arm, phase 1b/2 CARTITUDE-1 study (NCT03548207), pts received a single infusion of ciltacabtagene autoleucel (cilta-cel), a CAR-T cell therapy targeting BCMA. At the final protocol-specified analysis (27.7-mo median follow-up [MFU]), overall response rate (ORR) was 98%, with 83% stringent complete response (CR); 27-mo rates of progression-free survival (PFS) and OS were 55% and 70%, respectively. Here, we report study closeout results. Methods: Eligible pts received ≥3 prior lines of therapy (LOT) or were double refractory to a proteasome inhibitor (PI) and immunomodulatory drug (IMiD); and had received prior PI, IMiD, and anti-CD38 antibody therapy. Primary endpoint was ORR and safety; secondary endpoints included PFS, OS, and minimal residual disease (MRD) negativity at 10-5. Results: 97 pts received cilta-cel (median age 61 years [y]; median 6 prior LOT; 42% penta-drug refractory; 88% triple-class refractory; 99% refractory to last LOT). As of October 14, 2022, MFU was 33.4 mo (range, 1.5-45.2). Median (m) duration of response was 33.9 mo (95% CI, 25.5–not estimable [NE]). mPFS was 34.9 mo (95% CI, 25.2–NE), with an estimated 47.5% progression free and alive at 36 mo. mOS was not reached (NR), with an estimated 62.9% survival at 36 mo. Of 49 MRD-evaluable pts, 26 had MRD negativity sustained for ≥12 mo, of which 20 had sustained MRD-negative ≥CR. mPFS was NR in these subgroups (Table). 18 pts were MRD negative with ≥CR at 24 mo post infusion. No new safety signals and no new neurotoxicity events were reported since the 27.7-mo MFU. 6 new cases of second primary malignancy were reported, including 2 cases of basal cell carcinoma and 1 case each of myelodysplastic syndrome, B-cell lymphoma, melanoma, and prostate cancer. 5 additional deaths occurred (progressive disease [PD], n=3; pneumonia and sepsis, n=1 each [both unrelated to cilta-cel]), for a total of 35 (PD, n=17; unrelated to cilta-cel, n=12; related, n=6). Conclusions: Longer mPFS was observed after a single infusion of cilta-cel than any previously reported therapy in heavily pretreated pts with RRMM. Achieving CR and/or sustained MRD negativity was associated with prolonged PFS. Pts continue to be followed for safety and survival in the 15-y CARTINUE long-term study (NCT05201781; MMY4002). Clinical trial information: NCT03548207 . [Table: see text]

MagnetisMM-6: An open-label, multicenter, randomized phase 3 study of elranatamab + daratumumab + lenalidomide (EDR) versus daratumumab + lenalidomide + dexamethasone (DRd) in transplant ineligible (TI) patients with newly diagnosed multiple myeloma (NDMM).

TPS8065 Background: Elranatamab, a humanized bispecific antibody targeting B cell maturation antigen (BCMA) on myeloma cells and CD3 on T cells, has shown promising efficacy and acceptable safety in clinical studies, as monotherapy (MagnetisMM-3, NCT04649359) and in combination with daratumumab (MagnetisMM-5, NCT05020236), in the treatment of patients with relapsed/refractory multiple myeloma (RRMM). Despite recent advances in the treatment of NDMM, MM remains incurable and more effective treatment options are needed. The aim of the MagnetisMM-6 study (NCT05623020) is to evaluate EDR versus DRd for TI patients with NDMM. Methods: MagnetisMM-6 is an ongoing, open-label, 2-arm, multicenter, randomized phase 3 study estimated to enroll ~646 patients. There are 2 parts: Part 1 evaluates the safety and recommended phase 3 dose (RP3D) of EDR: Part 2 evaluates the efficacy and safety of EDR at RP3D vs DRd in TI patients with NDMM. TI is defined as age ≥65 or age &lt; 65 with comorbidities impacting the possibility of transplant. The primary endpoints of Part 2 are minimal residual disease (MRD) at 12 mo and progression-free survival. Secondary endpoints include overall and sustained MRD negativity rates, duration of MRD negativity, objective response rate, complete response (CR) rate, time to response, duration of response, duration of CR, overall survival, safety, quality of life, immunogenicity, and pharmacokinetics. Part 1 includes TI patients with NDMM as well as patients with RRMM who have received 1−2 prior lines of therapy including ≥1 immunomodulatory drug and ≥1 proteasome inhibitor. Part 2 includes only TI patients with NDMM. Key inclusion criteria are: ≥18 y; a diagnosis of MM (according to International Myeloma Working Group [IMWG] criteria); an ECOG performance status ≤2; and measurable disease based on IMWG criteria (serum M-protein ≥0.5 g/dL, urinary M-protein excretion ≥200 mg/24 hr, or involved serum free light chain [FLC] ≥100 mg/L and abnormal serum immunoglobulin κ:λ FLC ratio [ &lt; 0.26 or &gt; 1.65]). Key exclusion criteria are: smoldering MM; monoclonal gammopathy; Waldenström’s macroglobulinemia; plasma cell leukemia; active, uncontrolled bacterial, fungal, or viral infections; previous systemic treatment for MM (NDMM patients only); previous treatment with a BMCA-directed therapy or anti-CD38-directed therapy ≤6 mo of the first dose of study treatment (RRMM patients only); or stem cell transplant ≤3 mo of the first dose of study treatment or active graft versus host disease (RRMM patients only). As of February 2023, the study is open and enrolling at 9 sites in 5 countries. Clinical trial information: NCT05623020 .

Evaluation of ctDNA in a phase I/II trial in relapsed or refractory large B‐cell lymphoma of epcoritamab, a novel, subcutaneous CD3xCD20 bispecific T‐cell–engaging antibody

Introduction: The emergence of novel, more potent therapeutics in the treatment of patients with large B-cell lymphoma (LBCL) has resulted in higher rates of responses and highlighted a need for additional methods, such as minimal residual disease (MRD), to determine the depth and quality of response and potentially guide duration of treatment. Epcoritamab (DuoBody®-CD3xCD20) is a subcutaneously (SC) administered bispecific antibody (bsAb) that simultaneously binds to CD3 on T cells and CD20 on malignant B cells, inducing activation and cytotoxic activity of T cells for the killing of malignant CD20 B cells. In the pivotal epcoritamab trial, a correlation was demonstrated between MRD by clonoSEQ® (Adaptive Biotechnologies) and long-term outcomes. These findings led to additional analyses to further clarify the clinical use of ctDNA. As the evaluation of ctDNA in LBCL has not been standardized, we have expanded our investigation of the utility of ctDNA measurements from the initial analysis with the clonoSEQ assay to the AVENIO ctDNA assay (Roche). Here we present additional exploratory analyses of ctDNA using the AVENIO assay. Methods: Patients with relapsed/refractory (R/R) LBCL enrolled in EPCORE NHL-1 expansion phase (NCT03625037) received SC epcoritamab administered in 28-d cycles. ctDNA was measured using the clonoSEQ and AVENIO ctDNA assays at protocol-specified timepoints. Specimens were collected in EDTA and Streck cfDNA tubes, respectively, based on the recommended sample type at the time of study initiation. Plasma ctDNA levels were quantified per sample as count per mL (CPM) and mutant molecules per mL (MMPM) for clonoSEQ and AVENIO, respectively. Results: ctDNA quantification was concordant between the assays when within the dynamic range of the clonoSEQ assay (>80% in paired samples tested); however, a greater sensitivity of the AVENIO assay was observed, allowing further exploratory analyses of ctDNA using this platform. Consistent with prior observations, baseline ctDNA levels were associated with key clinical parameters, including LDH, TMTV, ECOG, and IPI. In patients who responded to epcoritamab, ctDNA levels decreased rapidly, with the majority of patients achieving CR having a deep ctDNA response by C3D1. Additional patients achieved MRD-negative status at later evaluations with continued therapy. MRD-negative status at C3D1, measured as absolute or relative change from baseline, was associated with longer progression free survival (PFS) and sustained MRD negativity throughout the duration of treatment. The research was funded by: Genmab A/S and AbbVie Keywords: Aggressive B-cell non-Hodgkin lymphoma, Liquid biopsy, Minimal residual disease Conflicts of interests pertinent to the abstract. D. Soong Employment or leadership position: Genmab C. Thieblemont Consultant or advisory role: AbbVie, Amgen, BMS/Celgene, Cellectis, Gilead Sciences, Kite, Novartis, Roche, Incyte, Janssen, Takeda Honoraria: AbbVie, Amgen, Bayer, Cellectis, Gilead Sciences, Incyte, Janssen, Kite, Novartis, Takeda Research funding: BMS/Celgene, Hospira, Roche Educational grants: AbbVie, Amgen, BMS/Celgene, Cellectis, Gilead Sciences, Kite, Novartis, Roche J. Karavitis Employment or leadership position: Genmab B. Hess Consultant or advisory role: ADC Therapeutics, BMS P. Caimi Consultant or advisory role: ADC Therapeutics, BMS, Beigene, Genentech, Lilly, Takeda, Kite pharma, Incyte, Novartis, MEI pharma Research funding: Genentech, Abbvie, ADC Therapeutics T. Feldman Consultant or advisory role: AbbVie, AstraZeneca, Epizyme, Genmab, Gilead/Kite, Karyopharm, Takeda, Seagen Other remuneration: Seagen: Speakers Bureau M. Hutchings Consultant or advisory role: AbbVie, Celgene, Genmab, Janssen, Roche, Takeda Research funding: Celgene, Genentech, Genmab, Incyte, Janssen, Novartis, Roche, Takeda (All Paid to Institution) A. Sureda Employment or leadership position: AbbVie Consultant or advisory role: Takeda, BMS/Celgene, Novartis, Janssen, MSD, Amgen, GSK, Sanofi, Kite, Mundipharma, Bluebird Honoraria: Takeda, BMS/Celgene, Novartis, Janssen, MSD, Amgen, GSK, Sanofi, Kite Research funding: Takeda Educational grants: Takeda, BMS/Celgene, Roche Other remuneration: Takeda, BMS/Celgene, Novartis, Janssen, MSD, Amgen, GSK, Sanofi, Kite: Speakers Bureau E. Szafer-Glusman Employment or leadership position: AbbVie M. Sacchi Employment or leadership position: Genmab M. Jure-Kunkel Employment or leadership position: Genmab N. Adya Employment or leadership position: Genmab C. Chiu Employment or leadership position: Genmab

MagnetisMM-7: An open-label, multicenter, randomized phase 3 study of elranatamab versus lenalidomide in post-transplant patients with newly diagnosed multiple myeloma.

TPS8066 Background: Elranatamab is a humanized bispecific antibody targeting B cell maturation antigen (BCMA) on myeloma cells and CD3 on T cells. Elranatamab has shown promising efficacy and acceptable safety in pts with relapsed and/or refractory multiple myeloma (MM). The aim of the MagnetisMM-7 study is to evaluate elranatamab monotherapy vs lenalidomide monotherapy in pts with newly diagnosed MM (NDMM) after undergoing autologous stem cell transplant (ASCT). Methods: MagnetisMM-7 is an ongoing, open-label, 2-arm, multicenter, randomized phase 3 study estimated to enroll ~700 pts. ClinicalTrials.gov ID: NCT05317416. Pts are randomized to receive either subcutaneous elranatamab or oral lenalidomide once daily. After initial step-up dosing, two alternative dosing regimens of elranatamab are examined. The primary endpoint is progression-free survival (PFS) assessed by blinded independent review per International Myeloma Working Group (IMWG) criteria (up to ~5 y). Secondary endpoints include overall survival, minimal residual disease (MRD) negativity rate at 12 mo after randomization per IMWG criteria as assessed via next-generation sequencing (NGS), sustained MRD negativity rate at 24 mo after randomization as assessed via NGS, PFS by investigator, duration of MRD negativity, complete response (CR) rate, duration of CR, safety, quality of life, immunogenicity, and pharmacokinetics. Key inclusion criteria are: ≥18 y; a diagnosis of MM with measurable disease according to IMWG criteria; history of induction therapy for NDMM, followed by high dose therapy and ASCT with or without consolidation; partial response or better according to IMWG criteria; identification of the dominant malignant clone; and Eastern Cooperative Oncology Group performance status ≤1. Randomization must occur ≤120 d from ASCT; for pts who receive consolidation therapy after ASCT, randomization must occur ≤60 d of consolidation and ≤7 mo of ASCT. Key exclusion criteria are: plasma cell leukemia; amyloidosis; Waldenström's macroglobulinemia; POEMS syndrome; known active CNS involvement or clinical signs of myelomatous meningeal involvement; previous MM maintenance treatment; prior treatment with BCMA-targeted therapy; any other active malignancy ≤3 y of enrollment; active, uncontrolled bacterial, fungal, or viral infection; and previous administration of an investigational drug or vaccine ≤30 d or 5 half-lives preceding the first dose of study treatment. As of February 2023, the study is open and enrolling at 29 sites in 13 countries. Clinical trial information: NCT05317416 .

Integrated analysis of next generation sequencing minimal residual disease (MRD) and PET scan in transplant eligible myeloma patients

Minimal residual disease (MRD) assays allow response assessment in patients with multiple myeloma (MM), and negativity is associated with improved survival outcomes. The role of highly sensitive next generation sequencing (NGS) MRD in combination with functional imaging remains to be validated. We performed a retrospective analysis on MM patients who underwent frontline autologous stem cell transplant (ASCT). Patients were evaluated at day 100 post-ASCT with NGS-MRD and positron emission tomography (PET-CT). Patients with ≥ 2 MRD measurements were included in a secondary analysis for sequential measurements. 186 patients were included. At day 100, 45 (24.2%) patients achieved MRD negativity at a sensitivity threshold of 10−6. MRD negativity was the most predictive factor for longer time to next treatment (TTNT). Negativity rates did not differ according to MM subtype, R-ISS Stage nor cytogenetic risk. PET-CT and MRD had poor agreement, with high rates of PET-CT negativity in MRD-positive patients. Patients with sustained MRD negativity had longer TTNT, regardless of baseline risk characteristics. Our results show that the ability to measure deeper and sustainable responses distinguishes patients with better outcomes. Achieving MRD negativity was the strongest prognostic marker and could help guide therapy-related decisions and serve as a response marker for clinical trials.

Normalization of the Immunological Microenvironment and Sustained Minimal Residual Disease Negativity: Do We Need Both for Long-Term Control of Multiple Myeloma?

Over the past two decades, the treatment landscape for multiple myeloma (MM) has progressed significantly, with the introduction of several new drug classes that have greatly improved patient outcomes. At present, it is well known how the bone marrow (BM) microenvironment (ME) exerts an immunosuppressive action leading to an exhaustion of the immune system cells and promoting the proliferation and sustenance of tumor plasma cells. Therefore, having drugs that can reconstitute a healthy BM ME can improve results in MM patients. Recent findings clearly demonstrated that achieving minimal residual disease (MRD) negativity and sustaining MRD negativity over time play a pivotal prognostic role. However, despite the achievement of MRD negativity, patients may still relapse. The understanding of immunologic changes in the BM ME during treatment, complemented by a deeper knowledge of plasma cell genomics and biology, will be critical to develop future therapies to sustain MRD negativity over time and possibly achieve an operational cure. In this review, we focus on the components of the BM ME and their role in MM, on the prognostic significance of MRD negativity and, finally, on the relative contribution of tumor plasma cell biology and BM ME to long-term disease control.

Carfilzomib induction, consolidation, and maintenance with or without autologous stem-cell transplantation in patients with newly diagnosed multiple myeloma: pre-planned cytogenetic subgroup analysis of the randomised, phase 2 FORTE trial

Carfilzomib induction, consolidation, and maintenance with or without autologous stem-cell transplantation in patients with newly diagnosed multiple myeloma: pre-planned cytogenetic subgroup analysis of the randomised, phase 2 FORTE trial

Maintenance Therapy Cessation for Sustained MRD Negative Multiple Myeloma Patients

Introduction Maintenance therapy with lenalidomide (len) and other drugs is a cornerstone therapeutic strategy for sustaining deep durable remissions in multiple myeloma (MM). However, indefinite treatment, as currently recommended, may lead to financial, emotional, and physical toxicity. Current guidelines lack data on optimal duration of maintenance in MM patients (pts) who have achieved sustained negative minimal residual disease (MRD) status. Here, we present the first pre-planned interim results from a phase II study evaluating maintenance cessation in patients with sustained MRD negative status for at least 3 years at the time of enrollment on study. Methods The current two-stage designed study of fifty MM pts, having already demonstrated >3 years of durable MRD negative responses, will be evaluated for MRD negative sustainability after ceasing maintenance therapy. Enrolled pts stop maintenance therapy and undergo active surveillance for three years, including serum protein testing every 3 months, bone marrow MRD testing by multiparametric flow cytometry (single 10-color tube with limit of detection of at least 6x106 (6 cells in 1 million) every 6 months, and annual PET-CTs. Primary endpoint includes sustained MRD negative rate after 1 year. Secondary endpoints include sustained MRD negative rate 3 years of cessation, re-treatment responses, microbiome and immune studies, health-related quality of life outcomes (HRQoL), and progression-free survival (PFS). The first stage includes 15 pts, and if 8 or more remain MRD negative at the end of 1 year, study enrollment continues to stage two (n=35). Results At data cutoff, on July 31, 2022, twenty-three pts (15 - stage 1; 8 - stage 2) have been enrolled on study. Median follow-up was 14.8 months (95% LL-UL: 11.1 - 25.1) after study enrollment, included 17(74%) male and 6(26%) female; 19(83%) ISS-stage 1, 2(9%) ISS-stage 2, and 2(9%) ISS-stage 3; and 4(17.3%) pts with high-risk cytogenetics [1 - t(4,14) and t(14,16); 1 - t(4,14) and +1q21gain; 2 - +1q21gain]. All pts enrolled onto study were receiving lenalidomide maintenance at the time. For stage 1, 13/15 (87%) remained MRD negative at 12 months of stopping maintenance therapy, and study accrual is ongoing with enrollment of 8 additional pts onto second stage. Overall, MRD negative sustained rates at 6 months and 12 months are 17/18 (94%) (95% CI: 73%-99%) and 14/16 (88%) (95% CI: 62%-98%), respectively. Progression free survival at 12 months was 94% (95% CI: 83%-100%). Two pts converted from MRD negative to MRD positive disease states while meeting clinical progression criteria with new FDG avid bone lesions. These pts have transitioned to new regimens: Pt 13 initiated carfilzomib, pomalidomide, and dexamethasone with VGPR; Pt 2 with a plan to initiate daratumamab-based therapy locally. Pt 10 converted to MRD positivity without clinical progression and opted to restart maintenance therapy with repeat MRD testing pending. Among the three MRD converters, one pt demonstrated standard risk cytogenetics and two pts had unknown risk cytogenetics. Additional HRQoL outcome data will be presented at the time of the meeting. Conclusions Initial first stage results of stopping maintenance in sustained MRD negative patients (>3 years) warrants further investigation and study continuation. This study and similar ones, such as MRD2STOP (NCT04108624), set a benchmark for future trials investigating maintenance cessation. One such trial includes SWOG 1803, which randomizes maintenance continuation vs. discontinuation in two-year MRD negative sustained patients. While maintenance therapy demonstrates clear benefit for MM patients, feasibility of treatment-free periods remain an unanswered critical question in the field. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

A Fixed-Duration Immunochemotherapy Approach Combined with Ibrutinib in CLL Produces Deep and Sustained MRD Responses: 5.5-Year Results from the Icll-07 Filo Trial

Introduction In previously untreated, medically fit patients with chronic lymphocytic leukemia (CLL), the availability of targeted agents has led to research interest in achieving deep, durable remissions and improving survival outcomes. The phase II ICLL-07 (NCT02666898) trial by the French Innovative Leukemia Organization (FILO) evaluated a fixed-duration (15-month) immunochemotherapy approach (no more than 4 fludarabine/cyclophosphamide [FC]-obinutuzumab cycles). Primary analysis showed the approach was safe and 62.2% (84/135) of all patients enrolled achieved complete response (CR) with bone marrow (BM) minimal residual disease (MRD) <0.01% (Michallet et al Lancet Haematol 2019;6:e470-9). Follow-up at median 37 months from treatment start showed a persistent MRD benefit beyond end of treatment, high survival rates, and low long-term toxicity (Michallet et al Blood 2021;137:1019-23). Here we report long-term results at median 64 months from treatment start (data cut-off 20 May 2022). Methods Between 27 October 2015 and 16 May 2017, 135 previously untreated, medically fit patients with CLL were enrolled from 27 FILO centers. All received obinutuzumab 1000 mg (8 infusions over 6 cycles) plus ibrutinib (420 mg/day for 9 months). Following evaluation at D1 M9 (N=130 evaluable), those in CR with BM MRD <0.01% then continued only ibrutinib 420 mg/day for 6 additional months (I arm; n=10); otherwise, patients received 4 cycles of FC-obinutuzumab 1000 mg alongside continuing ibrutinib 420 mg/day for 6 additional months (I-FCG arm; n=115). Beyond end of treatment, patients were followed for peripheral blood (PB) MRD every 6 months, response every 3 months, progression-free/overall survival (PFS/OS), and safety. MRD was assessed by 8-color flow cytometry, using a highly sensitive (10-6) technique developed by the FILO group that enables subdivision of classical MRD <0.01% into low-level positive MRD <0.01% and undetectable MRD. Results At D1 M16, undetectable PB MRD rates were 80.0% (8/10) in the I arm and 92.5% (99/107) in the I-FCG arm. Beyond end of treatment, in the I arm the undetectable PB MRD rate decreased rapidly, and by M40 all patients had PB MRD positivity (≥0.01% or low-level positive <0.01%). In the I-FCG arm, the undetectable PB MRD rate was 76.3% (61/80) at M40, and of patients currently investigated at M64, 50/62 (80%) still had undetectable PB MRD (Figure 1). Four relapses occurred beyond end of treatment, including 2 CLL progressions (both Richter's syndrome). Throughout follow-up, no differences in undetectable PB MRD rates were apparent in the I-FCG arm according to the IGHV -mutated versus unmutated status (currently at M64: 20/27 versus 25/35, P=0.26). Overall 4-year PFS and OS rates (95% confidence intervals) were 95.5% (92% to 99 %) and 96.2% (93% to 99.5%), respectively. Of 12 deaths overall, 7 occurred beyond end of treatment, with 5 since last publication due to Richter's syndrome at M50, COVID at M50, lung cancer at M50, myelodysplastic syndrome at M60, and acute myeloid leukemia at M69. Other serious adverse events since last publication were metastatic prostate adenocarcinoma at M50 and suspicion of cerebrovascular accident at M65. Conclusion Long-term results from the ICLL-07 trial in previously untreated, medically fit patients with CLL demonstrated that that our fixed-duration (15-month) immunochemotherapy approach produced deep and sustained undetectable PB MRD responses that were correlated to PFS, without excess toxicity. These long-term MRD results remain the best to date even compared to the new targeted therapy combinations ie ibrutinib +veneteclax or obinutuzumab + venetoclax A randomized trial is needed to compare our approach with a chemotherapy-free strategy. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Multicenter Open Label Phase 3 Study of Isatuximab Plus Lenalidomide and Dexamethasone with/without Bortezomib in the Treatment of Newly Diagnosed Non-Frail Transplant Ineligible Multiple Myeloma Elderly Patients (≥ 65; < 80 Years). IFM2020-05/Benefit

Background. The addition of the anti-CD38 monoclonal antibody (mAb) daratumumab to lenalidomide-dexamethasone (Rd) (MAIA) as part of the upfront treatment regimen for non-transplant eligible (NTE) newly diagnosed multiple myeloma (NDMM) has considerably increased survival. Interestingly, while median PFS reached 5 years, the sustained minimal residual disease (MRD) negativity rate was lower than 15%. To continue improving the treatment of NTE NDMM and allow most patients to survive with only one line of treatment, sustained MRD negativity rates need to further increase. Two randomized phase III studies are investigating the quadruplet combination of anti-CD38 mAb + bortezomib + Rd in the same NTE NDMM population, IMROZ (NCT03319667) and CEPHEUS (NCT03652064), with isatuximab and daratumumab, respectively, and VRd as the comparator arm. The design of these studies is expected to demonstrate the added value of an anti-CD38 mAb to VRd. However, VRd might be considered suboptimal SOC in NTE NDMM compared to the triplet-based regimen Dara-Rd until progression, given the results of the median PFS in the MAIA trial, with an unprecedented 5-year median PFS. We hypothesized that adding a proteasome inhibitor (PI) to the anti-CD38 mAb + Rd combination would significantly increase the sustained MRD negativity rate compared to the anti-CD38 mAb + Rd combination, the optimal standard of care (SOC) today in the NTE NDMM. We therefore have conducted the present study of Isa-VRd compared to Isa-Rd (IFM2020-05/Benefit). Benefit has fully enrolled as of August 2022, and there has been no safety warnings from the safety committee with the prolonged use of bortezomib on a weekly basis in combination to Isa-Rd. Study Design and Methods. 270 NTE NDMM patients, aged 65-79 years old and non-frail, were randomized and assigned in a 1:1 ratio to either the anti-CD38 mAb isatuximab + Rd (Isa-Rd) or isatuximab + VRd (Isa-VRd lite) (NCT04751877). Stratification across arms was done according to high-risk MM, age cutoff of 75 years and study centers. Patients receive isatuximab IV 10 mg/kg on days 1, 8, 15, and 22 of cycle 1, days 1 and 15 from cycle 2 to 12 and day 1 from cycle 13 onward, 28-day cycles. Lenalidomide and dexamethasone were given orally as approved. Bortezomib was administered weekly and subcutaneously on days 1, 8, 15 at 1.3 mg/m² from cycle 1 to 12 and on days 1, 15 from cycle 13 to 18, and then stopped. All patients will discontinue dexamethasone after cycle 12. Patients will then continue receiving Isa-Rd until progression in both arms. The primary objective is to evaluate the MRD negativity rate at 10-5 at 18 months in both arms. The study will be considered positive if the MRD negativity rate at 10-5 at 18 months is >30% in the Isa-VRd arm, and twice as much at the same time point in the Isa-Rd arm. Key secondary objectives include the survival analysis (OS, PFS, EFS, TTNT), response rates, duration of response, and safety. The study is estimated to read out December 2023, 18 months after the last patient enrolls.

Free from Maintenance Drug Therapy in Multiple Myeloma (The FREEDMM Trial): A Pilot Study of Minimal Residual Disease (MRD)-Driven Discontinuation of Maintenance

Background Induction therapy followed by autologous stem cell transplant (ASCT) and maintenance is the current standard of care for the treatment of newly diagnosed multiple myeloma (NDMM). However, indefinite maintenance therapy after ASCT carries both significant clinical and financial toxicities. While minimal residual disease (MRD) testing has become part of routine standard of care, its use in guiding treatment decisions, in particular cessation of therapy, has not been established in the maintenance setting. We hypothesize that MRD monitoring could be used to guide clinical decision making, justifying cessation of maintenance therapy in a sub-group of patients with sustained MRD-negative remission. Study Design and Methods This is a phase 2 single-arm adaptive design study (NCT 05192122) for decision-making regarding maintenance therapy (Figure 1). Patients are eligible if they have a diagnosis of active MM, have completed at least 2 years of maintenance therapy post-ASCT, and meet International Myeloma Working Group (IMWG) criteria for very good partial response (VGPR) or complete response (CR). MRD testing is performed twice, at least one year apart, on bone marrow aspirate using next-generation sequencing (NGS) and MRD-negative status is defined at a threshold of 10-6. Patients with negative PET scan in VGPR or CR and sustained (i.e., twice, 1 year apart) MRD negative status discontinue maintenance therapy. MRD-positive patients continue continue maintenance and are taken off study. In patients who are MRD-negative and discontinue maintenance therapy, MRD testing will be re-assessed yearly for 3 years. At each time of MRD testing, MALDI-TOF spectrometry and measurement of circulating multiple myeloma cells (CMMCs) will be done in parallel to compare against MRD results. Health-related quality of life (HRQoL) will be assessed throughout and results on maintenance compared with those after discontinuation using the EORTC QLQ-MY20 questionnaire. This study will enroll 50 patients to address the primary objective of assessment for sustained MRD-negative status at 12 months after stopping maintenance therapy. For all patients, a 5-mL peripheral blood and bone marrow sample is collected and stored at the time of each standard of care bone marrow biopsy and will be used to characterize the immune microenvironment by Cellular Indexing of Transcriptomes and Epitopes by Sequencing (CITE-seq) of paired peripheral blood and bone marrow in MRD-negative and MRD-positive patients as well as of patients progressing after stopping therapy. Preliminary Results Enrollment into FREEDMM trial began in December 2021, and to date 20 patients in CR have undergone a first bone marrow for MRD assessment, with results pending in 9 patients. The median age is 66.5 (range: 39-76) years, and the majority of patients are either Black (n=7; 35%) or Hispanic (n=7; 35%). One patient has high risk disease (17p deletion). The median number of years of maintenance therapy completed is 4.2 (range: 2.14-7.9) years. 17 (85%) patients had a negative MALDI-TOF test at the time of the first marrow. Seven (63.6%) of 11 patients were found to be MRD-negative. MALDI-TOF failed to accurately correlate with MRD results in 2 patients. 40 paired peripheral blood (n=20) and bone marrow aspirate (n=20) samples have been collected for CITE-seq analysis. Pilot CITE-seq experiments captured 6,700-11,000 cells with between 38,000-68,000 reads per cell on one MRD-negative and one MRD-positive bone marrow aspirate and paired peripheral blood sample. CITE-seq results for these 20 patients will be presented at the conference. Conclusion: This phase 2 trial applies a novel clinical trial design with an adaptive strategy to explore use of MRD testing as a guide to discontinuing maintenance therapy in myeloma and represents one of the first studies to explore in parallel various measures of disease monitoring (i.e., MRD, MALDI-TOF, CMMCs, CITE-seq). Ongoing results will be reported at the conference. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Persistance or Reappearance of Serum Monoclonal Protein Detected By Mass Spectrometry Is a Major Prognostic Factor in Patients with Newly Diagnosed Multiple Myeloma

Introduction: Durability of minimal residual disease (MRD) based on bone marrow examination is associated with a progression-free survival (PFS) benefit when it is undetected for >6-12 months. However, MRD assessment is limited by the heterogeneous involvement of bone marrow and invasive nature of the procedure. In contrast, Mass-Fix is a mass spectrometry based blood test that can detect small amounts of monoclonal protein. Herein, we hypothesize that achieving sustained Mass-Fix negativity for at least 6 or 12 months, improves outcomes compared to patients with nonsustained Mass-Fix negativity. In addition, we assess the clinical outcome of patients with loss of Mass-Fix negativity. Methods: This retrospective cohort study included consecutive patients seen at Mayo Clinic Rochester with newly diagnosed multiple myeloma (MM). Patients achieving at least very good partial response, and who had serial Mass-Fix testing every 6-12 months were included in this study. MRD in bone marrow aspirate was measured by flow cytometry (threshold 1 tumor cell/105 white blood cells). The Kaplan Meier or Simon-Makuch methods were used to graph the survival function. Progression-free survival was defined from diagnosis or the landmark point (2 years after diagnosis) to progression or death from any cause. Results: We identified 443 patients with NDMM, between May 1, 2017 and May 31, 2020. Among these, 274 patients had marrow MRD examination during their follow-up. With a median follow-up of 41 months from diagnosis, 56% of patients achieved Mass-Fix negativity, 43% marrow MRD negativity, and 23% achieved both Mass-Fix and MRD negativity. Most patients received a bortezomib-lenalidomide-dexamethasone induction followed by autologous transplantation (73%). In a 2 year landmark analysis, patients achieving Mass-Fix negativity had a better PFS at 2-years from landmark (4 years from diagnosis) than patients who did not (86.7% vs. 70.0% , p<0.001). Similarly, in a landmark analysis, patients with negative marrow MRD had a better PFS than those with positive MRD (88.1% vs. 62.5%, p=0.027). However, overall survival was similar between patients achieving Mass-Fix or MRD negativity and those who did not. In patients with Mass-Fix negativity, 76% and 71% achieved sustained Mass-Fix negativity for ≥6 and ≥12 months, respectively. In a landmark analysis, a significant difference in 2-year PFS was observed between patients with sustained Mass-Fix negativity ≥6 months and < 6 months (94.1% vs. 78.9%, p=0.013, Figure 1A). Patients with sustained Mass-Fix negativity≥12 months and < 12 months had a better 2-year PFS in a landmark analysis (94.4 vs. 80.2, p=0.019). Similarly, in a landmark analysis, patients with sustained marrow MRD negativity for ≥12 months had a better 2-year PFS from the landmark (4 years from diagnosis) than patients with MRD negativity for <12 months (91.8% vs. 72.8%, p<0.001). Patients achieving both sustained Mass-Fix and marrow negativity for ≥6 months had a better 2-year PFS from the landmark than patients who did not in a landmark analysis (91.5% vs. 73.1%, p=0.001). In our cohort, 33% of patients achieving Mass-Fix negativity had a subsequent loss of Mass-Fix negativity by 4 years; median duration of Mass-Fix negativity was 27 months (95% CI 25-30 months). Nearly half of patients with loss of Mass-Fix negativity (39/81) had eventually progressive disease (PD) according to IMWG criteria. In a 2-year landmark analysis, 2-year PFS (4 years from diagnosis) was better in patients with ≥2 consecutive negative Mass-Fix than in patients with loss of Mass-Fix negativity (88.1% vs. 68.6%, p<0.001, Figure 1B). Patients with loss of Mass-Fix negativity after the first year following diagnosis had a better 2-year overall survival than patients with conversion before 1 year in a landmark analysis (100.0% vs. 90.6%, p=0.045). Finally, patients who achieved sustained Mass-Fix negativity for ≥6 months had a better 4-year PFS than patients with loss of sustained Mass-Fix negativity with Simon-Makuch method (94.0% vs. 28%, p<0.001). Conclusions: In summary, this study demonstrates that sustained Mass-Fix negativity may represent a robust evaluation of prognosis and disease control. Moreover, loss of Mass-Fix negativity is associated with a worse outcome and could be used as a marker for earlier treatment interventions in MM. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Clinical Impact of Next Generation Flow in Bone Marrow Vs Qip-Mass Spectrometry in Peripheral Blood to Assess Minimal Residual Disease in Newly Diagnosed Multiple Myeloma Patients Receiving Maintenance As Part of the GEM2014MAIN Trial

Introduction: GEM2014MAIN is a phase 3, multicenter, open-label, randomized trial exploring maintenance treatment with lenalidomide and dexamethasone (Rd) vs lenalidomide, dexamethasone and ixazomib (IRd) after autologous stem cell transplantation in newly diagnosed patients with multiple myeloma (MM). The study includes yearly analysis of minimal residual disease (MRD) in bone marrow (BM) by Next Generation Flow (NGF) and the results at year 2 guide further management. Mass spectrometry methods measuring low-level immunoglobulins have shown potential for peripheral-blood (PB) based MRD assessment in MM. Aim: In this study, we analyzed and compared the results and clinical impact of MRD evaluation in BM by NGF and in PB by quantitative immunoprecipitation mass-spectrometry (QIP-MS) during maintenance in patients enrolled in the GEM2014MAIN trial. Patients and Methods: Patients achieving at least stable disease at the end of the GEM2012MENOS65 trial were included in the GEM14MAIN, and randomized to receive Rd (lenalidomide 15mg po od days 1-21 and dexamethasone 20mg po od days 1-4 and 9-12) or IRd (Rd plus ixazomib 4mg po od days 1, 8 and 15) in cycles of 28 days. After two years of treatment, BM samples were analyzed by NGF (sensitivity of 3x10-6) as per protocol: if MRD was undetectable, maintenance was discontinued; if detectable, Rd with reduced dexamethasone at 20mg po od only days 1-4 was continued for 3 additional years. At the same time point, MRD was assessed in PB by QIP-MS with anti IgG/A/M, total k and total l beads using the EXENT system (The Binding Site, in development). The association of MRD detection by either method with progression-free survival (PFS) was assessed by the Kaplan-Meier method. Landmark analyses of PFS at 2 years post-maintenance were performed to minimize lead-time bias. Additional survival analyses were carried out to evaluate the clinical impact of MRD evolution during the study period. Results: 156 patients with paired BM/PB samples available after 2 years of maintenance were included in the analysis. NGF detected residual disease in 29% (45/156) of cases and EXENT in 24% (37/156). The results of both techniques were concordant in 85% of cases and discordances were due to 16 patients (10%) NGF+/EXENT- and 8 (5%) NGF-/EXENT+. Of note, 8/16 cases NGF+/EXENT- corresponded to light-chain MM (anti-free light chain beads were not used in this study). Therefore, overall, and considering NGF as a reference, the negative predictive value (NPV) of EXENT was 87% and the positive predictive value (PPV) of 78% (p<0.0001). With a median follow-up of 66 months from the start of the GEM14MAIN, MRD detection by either method associated with a shorter PFS at 5 years as compared to patients with undetectable MRD: NGF: 57% vs 89%, respectively; HR= 6.54 (2.92-14.67); p<0.0001; EXENT: 62%% vs 86%, respectively; HR= 4.79 (1.99-11.53); p=0.0005. We also analyzed the evolution of MRD between enrollment and after 2 years of maintenance, since we already had MRD results by both methods at the end of the GEM2012. Patients were grouped into 1) those with persistent MRD positivity at the two time points or converting from MRD- to + by either method and 2) those with sustained MRD negativity at the two time points or converting from MRD+ to - by either method. Both NGF and EXENT showed that persistent MRD+ or conversion from MRD- to MRD+ were associated with a shorter PFS at 66 months, compared to patients who remained MRD- or converted from MRD+ to MRD-: NGF: 54% vs 89%, respectively; HR = 8.9 (3.55-22.08); p <0.0001; EXENT: 61% vs 86%, respectively; HR: 4.95 (1.91-12.9); p=0.0010. Conclusions: Our study shows that, during maintenance, the identification of MRD by NGF and EXENT and its evolutionary pattern are both associated with a comparable clinical value in terms of PFS. Supported by a NPV of 87% as compared to NGF, mass spectrometry could be used to define the optimal time-point for BM-based MRD assessments as well as, alongside with standard methods, to introduce MRD adapted treatment approaches.

Fc-Mediated Antibody Effector Function, Inflammation Resolution and Oligoclonality on TCR Rearrangements Predict Sustained MRD Negativity in Newly Diagnosed Multiple Myeloma Treated with Immunotherapy Regimens

Background: Targeted immunotherapy combinations including anti-CD38 monoclonal antibody daratumumab have significantly increased the depth of response and clinical outcome in newly diagnosed multiple myeloma (NDMM). Despite this improvement, 30-40% of patients still progress early and fail to achieve sustained minimal residual disease (MRD) negativity through largely unknown resistance mechanisms. Here we integrate whole genome sequencing (WGS) and single cell RNA (scRNA), surface protein (CITE), and TCR sequencing from patients with NDMM to characterize genomic and immune microenvironment features related to the failure to achieve sustained remission. Methods: 5'single-cell RNA-sequencing with an additional capture of the TCR and surface protein markers (CITEseq) was performed at both induction (T1) and at the end of induction (T2) with DKRd (Daratumumab-Carfilzomib, Lenalidomide and dexamethasone). A total of 148,280 cells were analyzed for RNA and CITE from 17 patients at T1 and 18 at T2. Twenty-seven cell types were identified and changes in their gene expression were examined. Data were integrated with 40,000 healthy bone marrow cells from the Human Cell Atlas. For TCR-seq, a total of 22,882 ⍺β clonotypes were analyzed. Fc-mediated antibody effector function is associated with sustained MRD negativity The microenvironment changed drastically between diagnosis and end of induction. The achievement of sustained MRD negativity were associated with an expansion of activated CD56-bright NK cells at T1 (chi-squared=4, p=0.044). Furthermore, significant changes in the monocyte profile were seen between timepoints and response groups. We identified a subset of resident-like macrophages expressing markers such as IL1B and CXCL2 suggesting that there are some immune hot tumors that are associated with suboptimal responses. Although there weren't absolute differences in T-cell subsets, PCA analysis showed that the combination of CD8 effector 1, CD16+monocytes and CD56+NK profiles could be used to identify a subset of good responders achieving sustained MRD negativity. Inflammation resolution is associated with sustained MRD negativity when complete response is achieved, significant changes in the microenvironment were observed and expansion of CD16+ monocytes associated with sustained MRD negativity. These data were validated prospectively using flow cytometry (n=31). These data suggest that the presence of cells mediating Fc-dependent immune effector mechanisms at diagnosis could predict good response and the resolution of tumor induced inflammation after treatment is associated with anti-inflammatory CD16+ monocytes. Oligoclonality in T-cell is associated with treatment and response TCR analysis was available for 22,882 cells and showed that there were significantly fewer clonotypes between T1 and T2 (Kruskal-Wallis chi-squared = 4.0, df = 1, p-value = 0.044) reflecting both the impact of treatment, possible antigen selection, and/or the disappearance of the chronic antigen in the form of the malignant plasma cells. Patients that failed to achieve MRD negativity at T2 had significantly more clonotypes suggesting an ineffective T-cell response to residual tumor. Diversity analysis is currently ongoing. Conclusion: In this multilayered analysis we show changes that the composition of the microenvironment is related to the level of response in the context of DKRd treatment. Fc-mediated antibody effector function and inflammation resolution are associated with sustained MRD negativity phenotypes response suggesting a significant contribution of the microenvironment to response, opening the way for therapeutic manipulation to enhance response. TCR analysis reveals for the first time that oligoclonal profiles seen on treatment may influence the fitness of the immune response.