Final analysis of a phase II trial of daratumumab, carfilzomib, lenalidomide, and dexamethasone in newly diagnosed multiple myeloma without transplant.

We evaluated the efficacy and safety of 24 cycles of Dara in combination with carfilzomib (K), lenalidomide (R), and dexamethasone (d) without autologous stem cell transplant (ASCT) in newly diagnosed multiple myeloma (NDMM) irrespective of ASCT eligibility in a single-arm, phase II study. The primary endpoint was the rate of stringent complete response (sCR) and/or measurable residual disease (MRD) < 10-5 by next-generation sequencing (NGS) at the end of cycle 8 (C8). MRD was also assessed on peripheral blood samples using both the EXENT® system and liquid chromatography-mass spectrometry (LC-MS). Forty-two patients entered the treatment phase; forty were evaluable for the primary endpoint. The rate of sCR and/or MRD < 10-5 following C8 was 30/40 (75%), meeting the statistical threshold for efficacy. The 10-6 MRD negative rate improved with treatment beyond C8. Agreement between EXENT® and NGS was high and increased over time; agreement between LC-MS and NGS was lower. The estimated 3-year progression-free survival progression-free survival was 85%, and 3-year overall survival was 95%. Upper respiratory infections occurred in 67% (7% grade 3-4). There were no treatment-related deaths. Extended frontline Dara-KRd induced a high rate of sCR and/or MRD negativity; the rate and depth of MRD negativity improved beyond C8.

Mass Spectrometry-Based Assessment of M-protein in Peripheral Blood During Maintenance Therapy in Multiple Myeloma.

Mass spectrometry (MS) can detect multiple myeloma-derived monoclonal proteins in peripheral blood (PB) with high sensitivity, potentially serving as a PB assay for measurable residual disease (MRD). This study evaluated the significance of PB MS MRD negativity during post-transplant therapy in patients with newly diagnosed multiple myeloma. Serum samples from 138 patients treated in the phase 3 ATLAS trial of post-transplant maintenance with either carfilzomib, lenalidomide, dexamethasone or lenalidomide alone were analyzed using EXENT MS methodology. We established feasibility of measuring MRD by MS in PB in the post-transplant setting, despite unavailability of pre-treatment calibration samples. There was high agreement between MRD by MS in PB and paired BM MRD results at the 10-5 threshold, assessed by either next generation sequencing (NGS) or multiparameter flow cytometry (MFC) (70% and 67%, respectively). Agreement between PB MS and both BM MRD methods was lowest early after transplant and increased with time. MS negativity was associated with improved progression-free survival (PFS), which in landmark analysis reached statistical significance after 18 cycles post-transplant. Combined PB/BM MRD negativity by MFC or NGS was associated with superior PFS compared to MRD negativity by only one modality. Sustained MS negativity carried similar prognostic performance to sustained BM MRD negativity at the 10-5 threshold. Overall, post-transplant MS assessment was feasible and provided additional prognostic information to BM MRD negativity. Further studies are needed to confirm the role and optimal timing of MS in disease evaluation algorithms. The ATLAS trial is registered at www.clinicaltrials.gov as #NCT02659293.

A phase I study of selinexor combined with weekly carfilzomib and dexamethasone in relapsed/refractory multiple myeloma.

We performed a phase I study of weekly selinexor, carfilzomib, and dexamethasone (wSKd) in patients with relapsed/refractory multiple myeloma (MM). The primary objective was to identify the maximum tolerated dose (MTD) of wSKd. Secondary endpoints included overall response rate (ORR), progression-free survival (PFS), and overall survival (OS). Prior exposure/refractoriness to carfilzomib was permitted. Thirty patients were enrolled; 26 (87%) had triple-class exposed disease and 6 (20%) received chimeric antigen receptor (CAR) T-cell therapy. Dose level 2 (carfilzomib 70 mg/m2 Intravenous [IV] on Days 1, 8, and 15; selinexor 100 mg PO on Days 1, 8, 15, 22; dexamethasone 40 mg on Days 1, 8, 15, 22 of 28-day cycles) was chosen as the MTD, with no DLTs having occurred. The most common hematologic adverse events (AE) were thrombocytopenia (83%), anemia (70%), lymphopenia (50%), and neutropenia (50%). The most common nonhematologic AE were fatigue (70%), nausea (70%), diarrhea (53%), and anorexia (47%). The ORR was 21/30 (70%) overall and 18/23 (78%) at the MTD. At a median follow-up of 12.3 months, the median PFS was 5.3 months and median OS 23.3 months. Responses were similar in carfilzomib naïve and exposed patients. Long-term efficacy of wSKd is modest; wSKd could be employed as a bridging strategy to immunotherapies.

Elotuzumab and Weekly Carfilzomib, Lenalidomide, and Dexamethasone in Patients With Newly Diagnosed Multiple Myeloma Without Transplant Intent: A Phase 2 Measurable Residual Disease-Adapted Study.

Importance: Treatment of newly diagnosed multiple myeloma (NDMM) with a quadruplet regimen consisting of a monoclonal antibody, proteasome inhibitor, immunomodulatory imide, and corticosteroid has been associated with improved progression-free survival (PFS) compared with triplet regimens. The optimal quadruplet combination, and whether this obviates the need for frontline autologous stem cell transplant (ASCT), remains unknown. We evaluated elotuzumab and weekly carfilzomib, lenalidomide, and dexamethasone (Elo-KRd) without ASCT in NDMM. Objective: To investigate the efficacy of Elo-KRd using a measurable residual disease (MRD)-adapted design in NDMM regardless of ASCT eligibility. Design, Setting, and Participants: This multicenter, single-arm, phase 2 study enrolled patients between July 2017 and February 2021. Median follow-up was 29 months. Interventions: Twelve to 24 cycles of Elo-KRd; consecutive MRD-negative results at 10-6 by next-generation sequencing (NGS) after cycles 8 (C8) and 12 determined the duration of Elo-KRd. This was followed by Elo-Rd (no carfilzomib) maintenance therapy until disease progression. Main Outcomes and Measures: The primary end point was the rate of stringent complete response (sCR) and/or MRD-negativity (10-5) after C8 Elo-KRd. Secondary end points included safety, rate of response, MRD status, PFS, and overall survival (OS). As an exploratory analysis, MRD was assessed using liquid chromatography mass spectrometry (MS) on peripheral blood samples. Results: Forty-six patients were enrolled (median age 62 years, 11 [24%] aged >70 years). Overall, 32 (70%) were White, 6 (13%) were Black, 3 (6%) were more than 1 race, and 5 (11%) were of unknown race. Thirty-three (72%) were men and 13 (28%) were women. High-risk cytogenetic abnormalities were present in 22 (48%) patients. The rate of sCR and/or MRD-negativity after C8 was 26 of 45 (58%), meeting the predefined statistical threshold for efficacy. Responses deepened over time, with the MRD-negativity (10-5) rate increasing to 70% and MS-negativity rate increasing to 65%; concordance between MRD by NGS and MS increased over time. The most common (>10%) grade 3 or 4 adverse events were lung and nonpulmonary infections (13% and 11%, respectively). There was 1 grade 5 myocardial infarction. The estimated 3-year PFS was 72% overall and 92% for patients with MRD-negativity (10-5) at C8. Conclusions and Relevance: An MRD-adapted design using elotuzumab and weekly KRd without ASCT showed a high rate of sCR and/or MRD-negativity and durable responses. This approach provides support for further evaluation of MRD-guided deescalation of therapy to decrease treatment exposure while sustaining deep responses. Trial Registration: ClinicalTrials.gov Identifier: NCT02969837.