A Randomized Phase II Study of Daratumumab, Ixazomib, and Dexamethasone (DId, Arm A) Vs Daratumumab, Bortezomib and Dexamethasone (DVd) Followed By Daratumumab, Did (Arm B) in Newly Diagnosed Multiple Myeloma (DeRIVE) Study

Introduction: The safety and efficacy established by daratumumab (a CD38 monoclonal antibody)-based induction therapies for both transplant-eligible myeloma patients (based on CASSIOPEIA, and GRIFFIN trials) and transplant-ineligible patients (based on MAIA trial) have gained an accelerated momentum for adoption into regular clinical practice. In this context, to find the most optimal non-IMID based daratumumab-combination therapy as induction, we conducted a randomized phase 2 study to evaluate the safety and efficacy for in-class transition from bortezomib to ixazomib, stratified by transplant-eligibility and R-ISS.

Methods: Patients were randomized to receive Arm A [daratumumab, ixazomib and dexamethsone (DId) X 8 cycles)] or Arm B [(daratumumab, bortezomib and dexamethsone (DVd) x 3) followed by (DId x 5 cycles)] for the primary endpoint of ≥ very good partial response rate (VGPR) rate post-induction cycle 8. Several other secondary endpoints were evaluated including safety, overall repsonse rate (ORR), progression free survival (PFS) and overall survival (OS). Standard dosing schedule was used [DId: daratumumab IV 16 mg/kg on days 1, 8, 15, 22 every 28 days x 2 cycles; then on days 1, 15 every 28 days x 6 cycles and every 28 days during maintenance (or 1800 mg SC at the same schedule), ixazomib - 4 mg PO on Days 1, 8, and 15 every 28 days and dexamethasone - 40 mg PO on days 1, 8, 15 and 22 every 28 days; DVd: daratumumab IV 16 mg/kg on days 1, 8, 15, 22 every 28 days x 2 cycles; then on days 1, 15 every 28 days x 6 cycles and every 28 days during maintenance (or 1800 mg SC at the same schedule), bortezomib - 1.3 mg/m2 SC on days 1, 4, 8 and 11 every 21 day and dexamethasone - 40 mg PO on days 1, 8, 15 and 22 every 28 days]. Transplant eligible patients may receive stem cell collection and transplant after cycle 8. During the maintenance phase, patients receive DId as maintennace therapy for a total of 32 cycles. 52 subjects were enrolled at Winship Cancer Institute of Emory University between 07/2019 and 05/2022.

Results: The median age was 64 years for the 48 evaluable subjects [25 (52%) in arm A, 68 (48-87) and 23 (48%) in arm B, 61 (37-80), p<0.25]. 56% of the cohort was male (64 vs 48%, p=0.20), 48% were black (40% vs 56.5%, p=0.245). 20.8% had t(11;14), 29.2% had 1q abnormalities, 70.8% had hyperdiploidy, 25% had complex karyotype and 10.4% were high-risk [defined as presence of del17p, t(4;14) or t(14;16)]. 38 (81%) patients underwent an autologous stem cell transplant (72% in Arm A and 90.9% in Arm B, p=1.00). The primary endpoint favored arm B (Arm A vs Arm B ≥VGPR rate: 28% vs 56.5%, p<0.043). Similarly, the ORR favored arm B as well (Arm A vs Arm B ORR: 76% vs 95.7%, p<0.062). Post transplant ≥VGPR rates and ORR were 88.9% vs 95%, p=0.458 and 100% vs 100%, p=NS, respectively. At a median follow up of 35.2 months, 80% of the patients remain progression free as shown in figure 1. The adverse event profile was similar across both cohorts (grade 3/4 events occurred in 6 (24%) vs 7 (30%) for Arm A and B, respectively, p=0.27). There was no grade 3/4 peripheral neuropathy (PN), though grade 1/2 PN were higher in Arm B. There were two secondary primary malignancy reported in Arm B (prostate adenocarcinoma, esophageal adenocarcinoma). All together the safety signals were comparable between both arms.

Conclusion: This is one of the first studies showing the safety and efficacy of non-IMID based dara-combination induction therapies with in-class transition of bortezomib to ixazomib yielding higher response rates post-induction and post-transplant without compromising on the safety. 3-year PFS rate of close to 80% across both arms is for daratumumab and proteasome inhibitor combination therapy are highly encouraging and may be an alternative regimen for patients that may not tolerate IMIDs or that have a contraindication to receive IMIDs.