INTRODUCTION. Bortezomib, lenalidomide and dexamethasone (VRd) is considered a standard of care combination therapy for newly diagnosed multiple myeloma patients. Prior studies show that ~25% of patients treated with 8 cycles of VRd achieve minimal residual disease (MRD) negativity. Recently, 42% stringent complete response (sCR) rates were reported with the use of VRd combined with the CD38-targeted monoclonal antibody daratumumab (VRd-D). Prior studies using 8 cycles of bi-weekly carfilzomib 36 mg/m2 with lenalidomide and dexamethasone (bKRd) combination therapy in newly diagnosed multiple myeloma show ~40% MRD negativity rates. We were motivated to develop a phase 2 study (total N=82) using weekly dosing of carfilzomib 56 mg/m2 with lenalidomide and dexamethasone (wKRd) in combination with daratumumab (wKRd-D). Our study also included a parallel cohort of bi-weekly dosing of carfilzomib 36 mg/m2 with lenalidomide and dexamethasone (bKRd) in combination with daratumumab (bKRd-D). Primary end-point of our study was to rule out 60% and to target up to 80% MRD negativity rate.

METHODS. This is a two-arm, Phase II clinical trial based on Simon's optimal two-stage design. The once-a-week carfilzomib (wKRd) (N=41) has the following treatment schedule: 8 cycles of treatment; 28-day cycles with carfilzomib 20/56 mg/m2 days 1, 8, and 15; lenalidomide 25 mg days 1-21; dexamethasone 40 mg weekly cycles 1-4, 20 mg after cycle 4; and daratumumab 16 mg/kg days 1, 8, 15, and 22 cycles 1-2, days 1 and 15 cycles 3-6, and day 1 cycles 7-8. The bi-weekly carfilzomib (bKRd) (N=41): 8 cycles of treatment; 28-day cycles with carfilzomib 20/36 mg/m2 days 1, 2, 8, 9, 15 and 16; lenalidomide, dexamethasone, and daratumumab are given at the same doses/schedules as the weekly cohort. For fit patients, stem cell collection is recommended after 4 to 6 cycles of therapy; DKRd therapy is resumed after collection to a total of 8 cycles DKRd. Treatment response is being assessed with parallel bone marrow-based MRD assays (10-color single tube flowcytometry and invivoscribe IGHV sequencing); per IMWG guidelines both MRD assays allow detection of 1 myeloma cell in 100,000 bone marrow cells (10^-5). Baseline bone marrow samples are evaluated with targeted DNA sequencing for FISH-Seq and somatic mutational characteristics (myTYPE).

RESULTS. The first stage of the weekly cohort (wKRd-D) is fully enrolled (N=28) and the second stage of the cohort (N=13) is anticipated to complete enrollment shortly (total N=41). Currently, 29 patients meeting eligibility criteria were enrolled (14 males, 15 females) between October 2018 and August 2019. Baseline characteristics include; median age 59 years (range 36-70 years); 12 (41%) patients had high-risk FISH/SNP signature defined as one or more of the following: 1q+, t(4;14), t(14;16), t(14;20), and 17p-. At the submission of this abstract, 28 patients have completed one or more cycles wKRd-D; among these, 10 patients have completed therapy. The median number of cycles delivered is currently 6 (range 1-8). Seven of the 10 patients who have completed study treatment are MRD negative. So far, additional 8 patients have become MRD negative while on therapy. Thus, among patients treated on the weekly cohort (wKRd-D) and who were evaluable for the MRD primary end-point at this analysis, we found 15/18 (83%) to be MRD negative. We further show no added major clinical toxicities with wKRd-D compared to our institution standard of care bKRd. The bi-weekly carfilzomib cohort (bKRd-D) shows similar results to the weekly cohort (wKRd-D). With a comparable efficacy and safety profile coupled with a substantial reduction of the number of infusions (total of 51 vs 27 infusions with bKRd-D vs wKRd-D, respectively), we conclude that the weekly dosing (wKRd-D) may offer an attractive treatment modality for newly diagnosed multiple myeloma patients.

CONCLUSIONS. Among patients evaluable for the MRD primary end-point, in the absence of an autologous bone marrow transplant, we show an unprecedented 15/18 (83%) MRD negativity rate among newly diagnosed multiple myeloma patients treated on the weekly cohort (wKRd-D) using carfilzomib 56 mg/m2 dosing. Our promising results have prompted the development of a large randomized multi-center study ("ADVANCE") evaluating wKRd-D in relation to established standard of care, which is anticipated to start enrollment in Q3/Q4 of 2019.

Disclosures

Landgren:Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Adaptive: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Merck: Other: IDMC; Theradex: Other: IDMC; Abbvie: Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees; Karyopharm: Membership on an entity's Board of Directors or advisory committees. Lesokhin:GenMab: Consultancy, Honoraria; BMS: Consultancy, Honoraria, Research Funding; Juno: Consultancy, Honoraria; Janssen: Research Funding; Genentech: Research Funding; Takeda: Consultancy, Honoraria; Serametrix Inc.: Patents & Royalties. Mailankody:Juno: Research Funding; Celgene: Research Funding; Janssen: Research Funding; Takeda Oncology: Research Funding; CME activity by Physician Education Resource: Honoraria. Hassoun:Novartis: Consultancy; Celgene: Research Funding; Janssen: Research Funding. Smith:Fate Therapeutics and Precision Biosciences: Consultancy; Celgene: Consultancy, Patents & Royalties, Research Funding. Shah:Physicians' Education Resource: Honoraria. Landau:Caelum: Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Research Funding; Karyopharm: Consultancy, Honoraria; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Prothena: Membership on an entity's Board of Directors or advisory committees. Scordo:Angiocrine Bioscience, Inc.: Consultancy; McKinsey & Company: Consultancy. Arcila:Invivoscribe, Inc.: Consultancy, Honoraria. Ho:Invivoscribe, Inc.: Honoraria. Roshal:Auron Therapeutics: Equity Ownership, Other: Provision of services; Physicians' Education Resource: Other: Provision of services; Celgene: Other: Provision of Services. Dogan:Corvus Pharmaceuticals: Consultancy; Seattle Genetics: Consultancy; Celgene: Consultancy; Takeda: Consultancy; Novartis: Consultancy; Roche: Consultancy, Research Funding.

OffLabel Disclosure:

Dara-KRd is not an FDA approved combination therapy for newly diagnosed multiple myeloma.

Author notes

*

Asterisk with author names denotes non-ASH members.