MM-253 Efficacy, Safety, and Quality of Life (QoL) in Patients With Newly Diagnosed Multiple Myeloma (NDMM) After In-Class Transition (iCT) From Parenteral Bortezomib-Based Induction Therapy to All-Oral Ixazomib-Lenalidomide-Dexamethasone (IRd): Data From the Phase 4, Community-Based US MM-6 Study (Fully Accrued Cohort)

Abstract

Achieving prolonged therapy with parenteral proteasome inhibitors (PIs) in clinical practice can be challenging. To increase the duration of PI-based therapy, improve outcomes, and maintain QoL. Prospective study (NCT03173092) evaluating iCT from parenteral bortezomib-based induction to all-oral IRd. IRd was received for up to 39 cycles or until progression/toxicity (Manda CLML 2020). Interim data (N=101) were previously reported (Rifkin ASH 2021). We report results from the fully accrued study cohort (enrollment completed, May 2021; N=141). US community sites. Transplant-ineligible/delayed-transplant (≥24 months) NDMM patients with ≥stable disease after 3 cycles of bortezomib-based induction. Primary endpoint: 2-year progression-free survival (PFS) rate. Other endpoints included: key secondary, overall response rate (ORR; partial response [PR]+very good PR [VPGR]+complete response [CR]) and duration of treatment (DOT); secondary, overall survival (OS), safety, and QoL. At Feb-28-2022, 140 patients (median age, 72.5 years [range, 48-90]; 79% ≥65 years; 42% ≥75 years) had received IRd; 94% had ≥1 comorbidity at IRd initiation. Median follow-up was 20.0 months. 2-year PFS was 69% (95% confidence interval [CI]: 59-77%). ORR was 62% (CR, 8%; VGPR, 24%; PR, 30%) after bortezomib-based induction, increasing to 78% (CR, 33%; VGPR, 27%; PR, 18%) after iCT. At data cut-off, 28 patients (20%) were ongoing on IRd, median DOT with IRd was 10.0 months, and median duration of all PI-based treatment was 12.7 months. 2-year OS was 85% (95% CI: 76-90%). 66% of patients had grade ≥3 treatment-emergent adverse events (TEAEs) (treatment-related, 36%), 44% had serious TEAEs (treatment-related, 14%), and 6 on-study deaths had occurred. Most common TEAEs (any-grade/grade ≥3) were diarrhea (48%/9%), peripheral neuropathies not elsewhere classified (39%/4%), and fatigue (34%/4%). Modification/discontinuation of ixazomib, lenalidomide, or dexamethasone due to TEAEs occurred in 59%/15% of patients. Patient-reported QoL (EORTC QLQ-C30 Global Health Status/QoL score) and treatment satisfaction (TSQM-9 Global Satisfaction, Effectiveness, and Convenience scores) were maintained on IRd. Improved responses and promising PFS and OS were seen following iCT to IRd in these mostly elderly, community-treated patients with NDMM and comorbidities, with no adverse impact on QoL/treatment satisfaction. Safety results were consistent with previous reports.