Jackson GH, Pawlyn C, Cairns DA, de Tute RM, Hockaday A, Collett C, Jones JR, Kishore B, Garg M, Williams CD, Karunanithi K, Lindsay J, Rocci A, Snowden JA, Jenner MW, Cook G, Russell NH, Drayson MT, Gregory WM, Kaiser MF, Owen RG, Davies FE, and Morgan GJ
Background: Carfilzomib is a second-generation irreversible proteasome inhibitor that is efficacious in the treatment of myeloma and carries less risk of peripheral neuropathy than first-generation proteasome inhibitors, making it more amenable to combination therapy., Methods and Findings: The Myeloma XI+ trial recruited patients from 88 sites across the UK between 5 December 2013 and 20 April 2016. Patients with newly diagnosed multiple myeloma eligible for transplantation were randomly assigned to receive the combination carfilzomib, lenalidomide, dexamethasone, and cyclophosphamide (KRdc) or a triplet of lenalidomide, dexamethasone, and cyclophosphamide (Rdc) or thalidomide, dexamethasone, and cyclophosphamide (Tdc). All patients were planned to receive an autologous stem cell transplantation (ASCT) prior to a randomisation between lenalidomide maintenance and observation. Eligible patients were aged over 18 years and had symptomatic myeloma. The co-primary endpoints for the study were progression-free survival (PFS) and overall survival (OS) for KRdc versus the Tdc/Rdc control group by intention to treat. PFS, response, and safety outcomes are reported following a planned interim analysis. The trial is registered (ISRCTN49407852) and has completed recruitment. In total, 1,056 patients (median age 61 years, range 33 to 75, 39.1% female) underwent induction randomisation to KRdc (n = 526) or control (Tdc/Rdc, n = 530). After a median follow-up of 34.5 months, KRdc was associated with a significantly longer PFS than the triplet control group (hazard ratio 0.63, 95% CI 0.51-0.76). The median PFS for patients receiving KRdc is not yet estimable, versus 36.2 months for the triplet control group (p < 0.001). Improved PFS was consistent across subgroups of patients including those with genetically high-risk disease. At the end of induction, the percentage of patients achieving at least a very good partial response was 82.3% in the KRdc group versus 58.9% in the control group (odds ratio 4.35, 95% CI 3.19-5.94, p < 0.001). Minimal residual disease negativity (cutoff 4 × 10-5 bone marrow leucocytes) was achieved in 55% of patients tested in the KRdc group at the end of induction, increasing to 75% of those tested after ASCT. The most common adverse events were haematological, with a low incidence of cardiac events. The trial continues to follow up patients to the co-primary endpoint of OS and for planned long-term follow-up analysis. Limitations of the study include a lack of blinding to treatment regimen and that the triplet control regimen did not include a proteasome inhibitor for all patients, which would be considered a current standard of care in many parts of the world., Conclusions: The KRdc combination was well tolerated and was associated with both an increased percentage of patients achieving at least a very good partial response and a significant PFS benefit compared to immunomodulatory-agent-based triplet therapy., Trial Registration: ClinicalTrials.gov ISRCTN49407852., Competing Interests: I have read the journal’s policy and the authors of this manuscript have the following competing interests: RdeT and NR declare no conflict of interest. DAC, AH and CC, report research funding from Celgene Corporation, Amgen, and Merck Sharp and Dohme. GHJ has received consultancy fees, honoraria and speakers' bureau fees from Roche, Amgen, Janssen, and Merck Sharp and Dohme; and consultancy fees, honoraria, travel support, research funding, and speakers' bureau fees from Celgene Corporation and Takeda. CP has received consultancy fees, honoraria, and travel support from Amgen, Celgene Corporation, Janssen, Sanofi and Takeda Oncology. JRJ has received honoraria and research funding from Celgene Corporation. BK has received consultancy fees, travel support, and speakers' bureau fees from Celgene Corporation, Takeda, and Janssen. MG has received travel support, research funding, and speakers' bureau fees from Janssen; travel support from Takeda; and travel support and research funding from Novartis. CDW has received honoraria, travel support, and speakers' bureau fees from Takeda, Janssen, and Celgene Corporation; honoraria and speakers' bureau fees from Amgen; and honoraria from Novartis. KK has received travel support and research funding from Celgene Corporation and Janssen. JL has received consultancy fees from Janssen; travel support from Novartis and Takeda; consultancy fees and travel support from Bristol-Myers Squibb; and honoraria and travel support from Celgene Corporation. AR has received consultancy fees from Takeda and Sanofi Genzyme, honoraria from Celgene, Novartis, Takeda, Amgen, Janssen, travel support from AbbVie, Takeda and Janssen and has been part of advisory boards for Novartis, Janssen and Amgen. JAS has received speaker fees for educational events supported by Sanofi, Janssen, Jazz, Mallinckrodt, Actelion and Gilead and is a member of a trial IDMC for Kiadis Pharma. MWJ has received consultancy fees, honoraria, travel support, and research funding from Janssen; consultancy fees, honoraria, and travel support from Takeda and Amgen; consultancy fees, honoraria, and research funding from Celgene Corporation; and consultancy fees and honoraria from Novartis. GC has received consultancy fees, honoraria, research funding, and speakers' bureau fees from Takeda, Celgene Corporation, Janssen, and Amgen; consultancy fees and honoraria from Glycomimetics and Bristol-Myers Squibb; and consultancy fees, honoraria, and speakers' bureau fees from Sanofi. MTD has equity ownership in, and is on the board of directors and advisory committee of, Abingdon Health. WMG has received consultancy fees and research funding from Celgene Corporation; research funding from Amgen and Merck Sharp and Dohme; and honoraria from Janssen. MFK has received consultancy fees and travel support from Bristol-Myers Squibb and Takeda; consultancy fees from Chugai; consultancy fees and honoraria from Janssen and Amgen; and consultancy fees, honoraria, and research funding from Celgene Corporation. RGO has received honoraria and travel support from Takeda; consultancy fees and travel support from Janssen; consultancy fees, honoraria, and research funding from Celgene Corporation. FED has received consultancy fees and honoraria from Amgen, AbbVie, Takeda, Janssen, Celgene and Roche. GJM has received research funding from Janssen; consultancy fees and honoraria from Bristol-Myers Squibb, Roche, Amgen, GSK, Karyopharm and Takeda; and consultancy fees, honoraria, and research funding from Celgene Corporation.