Evaluation of Minimal Residual Disease (MRD) Negativity in Patients with Relapsed or Refractory Multiple Myeloma Treated in the Candor Study

Introduction: CANDOR is a multicenter, phase 3, randomized study of adult patients with relapsed or refractory multiple myeloma (RRMM) previously treated with 1-3 prior lines of therapy (NCT03158688). 466 patients received carfilzomib, dexamethasone, and daratumumab (KdD) or carfilzomib and dexamethasone (Kd) in 2:1 randomization (KdD: 312; Kd: 154). Based on the primary endpoint, KdD demonstrated superior progression-free survival (PFS) vs Kd (hazard ratio [HR], 0.63 [95% CI, 0.46-0.85]; P=0.0014). Deep responses and minimal residual disease (MRD) negativity have been associated with improved PFS for patients with RRMM. Herein, we present an analysis of MRD results from CANDOR. Methods: Details of the dose and schedule were previously reported (Dimopoulos et al., Lancet 2020). The rate of patients with confirmed CR which were MRD negative (MRD[-]CR) in bone marrow aspirate at 12 months (± 4 weeks) measured by next-generation sequencing (NGS; threshold, 1 tumor cell/10-5 white blood cells) was a prespecified key secondary endpoint. Exploratory analyses included MRD[-]CR at increasing sensitivity (10-4, 10-5, 10-6) and best overall response MRD[-] status at any time point. All reported responses were by Independent Review Committee and were analyzed for the Intent-to-Treat population. MRD[-] status is at <10-5 unless otherwise specified. Results: The best overall MRD[-]CR rate at any time was 13.8% vs 3.2% in the KdD vs Kd arm (Odds ratio [OR], 4.95; P<0.0001) and the MRD[-] rate regardless of overall response status was 22.8% vs 5.8% (OR, 5.15; P<0.0001). At the 12-month landmark, the MRD[-]CR rate was 12.5% vs 1.3% in the KdD vs Kd arm (OR, 11.3; P<0.0001) and the MRD[-] rate was 17.6% vs 3.9% (OR, 5.76; P<0.0001) with the proportion of patients with MRD[-]VGPR being 4.2% vs 2.6%, respectively. The MRD[-]CR rates at the 12-month landmark for KdD vs Kd were consistent across clinically relevant subgroups (Table). At the 12-month landmark, KdD treatment resulted in a greater proportion of CR rates (26.9% vs 9.7%) and deeper MRD responses than Kd. Among patients in CR, the depth of response as measured by NGS MRD level at the 12-month landmark was deeper for KdD relative to Kd: cutoff of >10-4, 36.9% vs 73.3%; 10-4 to 10-5, 16.7% vs 13.3%; 10-5 to 10-6, 23.8% vs 13.3%; <10-6, 22.6% vs 0% for KdD vs Kd, respectively (Figure). Similar to the results at the 12-month landmark, MRD responses independent of the landmark were deeper among patients in the KdD compared to the Kd arm. With median follow-up of 6 months from the 12-month landmark, no patient with MRD[-]CR response progressed or died. Additional post hoc analyses were conducted within patients randomized to KdD to explore prognostic characteristics for MRD[-]CR. Importantly, prior lenalidomide exposure did not meaningfully impact the MRD[-]CR rate at the 12-month landmark; 13.2% (25/189), 11.4% (14/123), and 13.1% (13/99) for naïve, exposed, and refractory subgroups, respectively. For prior bortezomib, the MRD[-]CR rates were 24% (6/25), 11.5% (33/287), and 6.8% (6/88) for naïve, exposed, and refractory subgroups, respectively. The rates of MRD[-]CR at the 12- month landmark within the KdD arm were consistent across subgroups: patients refractory to the last prior therapy (yes vs no, 10.9% vs 14.3%), number of prior regimens (1-2 vs 3 prior regimens; 13.2% vs 10.1%), prior transplant (yes vs no, 11.8% vs 13.7%), duration of first remission (≤2 vs >2 years, 12.3% vs 13% and ≤1 vs >1 year, 10.7% vs 13.4%), baseline creatinine clearance (≥15 to 75 years, 12.9% vs 8.0%), or dose intensity (< vs ≥ median) for carfilzomib or daratumumab (10.5% vs 14.9% and 9.8% vs 15.6%, respectively). Data on cytogenetics will be included at the time of presentation. Conclusion: At the primary analysis, patients treated with KdD achieved significantly higher MRD[-]CR rates vs Kd at the 12-month landmark. Among patients with an MRD[-]CR, the depth of MRD was deeper with KdD vs Kd. With a median of 6 months follow-up, no patient with an MRD[-]CR has progressed; duration of response will be updated at time of presentation. Within the KdD arm, lenalidomide exposure or refractoriness did not diminish the MRD[-]CR rate. These findings support the efficacy of the KdD regimen as an effective treatment for RRMM, including patients who have become lenalidomide refractory. Disclosures Landgren: Adaptive: Consultancy, Honoraria; Amgen: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria; Juno: Consultancy, Honoraria; Cellectis: Consultancy, Honoraria; BMS: Consultancy, Honoraria; Binding Site: Consultancy, Honoraria; Karyopharma: Research Funding; Merck: Other; Pfizer: Consultancy, Honoraria; Seattle Genetics: Research Funding; Juno: Consultancy, Honoraria; Glenmark: Consultancy, Honoraria, Research Funding; Cellectis: Consultancy, Honoraria; BMS: Consultancy, Honoraria; Takeda: Other: Independent Data Monitoring Committees for clinical trials, Research Funding; Binding Site: Consultancy, Honoraria; Karyopharma: Research Funding; Janssen: Consultancy, Honoraria, Other: Independent Data Monitoring Committees for clinical trials, Research Funding; Seattle Genetics: Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Glenmark: Consultancy, Honoraria, Research Funding; Takeda: Other: Independent Data Monitoring Committees for clinical trials, Research Funding; Janssen: Consultancy, Honoraria, Other: Independent Data Monitoring Committees for clinical trials, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Merck: Other. Weisel:Roche: Consultancy, Honoraria; Amgen: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Sanofi: Consultancy, Honoraria, Research Funding; Bristol-Myers Squibb: Consultancy, Honoraria; Adaptive: Consultancy, Honoraria; GlaxoSmithKline: Honoraria; Karyopharm: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria. Rosinol Dachs:Janssen: Honoraria; Celgene: Honoraria; Amgen: Honoraria; Takeda: Honoraria; Sanofi: Honoraria. Moreau:Sanofi: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Celgene/Bristol-Myers Squibb: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Novartis: Honoraria; Takeda: Honoraria; Abbvie: Consultancy, Honoraria. Hajek:PharmaMar: Consultancy, Honoraria; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Abbvie: Consultancy, Honoraria; Oncopeptides: Consultancy; Novartis: Consultancy, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding. Mollee:Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS/Celgene: 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; Pfizer: Membership on an entity's Board of Directors or advisory committees; Caelum: Membership on an entity's Board of Directors or advisory committees. Kim:Alexion Pharmaceuticals Inc.: Honoraria, Research Funding. Zhang:Amgen: Current Employment. Go:Amgen: Current Employment. Morris:Amgen: Current Employment. Usmani:Celgene: Other; Takeda: Consultancy, Honoraria, Other: Speaking Fees, Research Funding; Janssen: Consultancy, Honoraria, Other: Speaking Fees, Research Funding; SkylineDX: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; Merck: Consultancy, Research Funding; Incyte: Research Funding; Pharmacyclics: Research Funding; Array Biopharma: Research Funding; GSK: Consultancy, Research Funding; Sanofi: Consultancy, Honoraria, Research Funding; Abbvie: Consultancy; BMS, Celgene: Consultancy, Honoraria, Other: Speaking Fees, Research Funding; Amgen: Consultancy, Honoraria, Other: Speaking Fees, Research Funding

FlowCT for the analysis of large immunophenotypic datasets and biomarker discovery in cancer immunology

Large-scale immune monitoring is becoming routinely used in clinical trials to identify determinants of treatment responsiveness, particularly to immunotherapies. Flow cytometry remains one of the most versatile and high throughput approaches for single-cell analysis; however, manual interpretation of multidimensional data poses a challenge when attempting to capture full cellular diversity and provide reproducible results. We present FlowCT, a semi-automated workspace empowered to analyze large data sets. It includes pre-processing, normalization, multiple dimensionality reduction techniques, automated clustering, and predictive modeling tools. As a proof of concept, we used FlowCT to compare the T-cell compartment in bone marrow (BM) with peripheral blood (PB) from patients with smoldering multiple myeloma (SMM), identify minimally invasive immune biomarkers of progression from smoldering to active MM, define prognostic T-cell subsets in the BM of patients with active MM after treatment intensification, and assess the longitudinal effect of maintenance therapy in BM T cells. A total of 354 samples were analyzed and immune signatures predictive of malignant transformation were identified in 150 patients with SMM (hazard ratio [HR], 1.7; P < .001). We also determined progression-free survival (HR, 4.09; P < .0001) and overall survival (HR, 3.12; P = .047) in 100 patients with active MM. New data also emerged about stem cell memory T cells, the concordance between immune profiles in BM and PB, and the immunomodulatory effect of maintenance therapy. FlowCT is a new open-source computational approach that can be readily implemented by research laboratories to perform quality control, analyze high-dimensional data, unveil cellular diversity, and objectively identify biomarkers in large immune monitoring studies. These trials were registered at www.clinicaltrials.gov as #NCT01916252 and #NCT02406144.© 2022 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved