BOSTON – A carfilzomib-based quadruplet can improve outcomes in transplant-eligible patients with newly diagnosed multiple myeloma, a phase 3 trial suggests.
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Histopathological image of multiple myeloma. Smear preparation of bone marrow aspirate stained with May-Grünwald-Giemsa procedure.
In the Myeloma XI trial, carfilzomib plus cyclophosphamide, lenalidomide, and dexamethasone (KCRD) significantly prolonged progression-free survival (PFS), compared with cyclophosphamide-lenalidomide-dexamethasone (CRD) or cyclophosphamide-thalidomide-dexamethasone (CTD).
“KCRD was associated with a very high response rate and a high MRD [minimal residual disease]-negative rate at the end of induction, and it significantly improved progression-free survival compared to the triplet combinations,” said Charlotte Pawlyn, PhD, of The Institute of Cancer Research in London.
Dr. Pawlyn reported these findings at the International Myeloma Workshop held by the International Myeloma Society.
The phase 3 Myeloma XI trial enrolled 1,056 patients with newly diagnosed myeloma who were eligible for transplant. The patients were randomized to receive KCRD (n = 526), CRD (n = 265), or CTD (n = 265) as induction.
Baseline characteristics were well balanced between the treatment arms. The median age was 61 years in the KCRD and CTD arms and 62 years in the CRD arm (overall range, 33-75 years). Roughly 60% of patients in each arm were men.
About 50%-60% of patients in each arm had standard-risk cytogenetics, which was defined as the absence of any cytogenetic lesions. About 30%-40% of patients in each arm had high-risk cytogenetics, meaning they had one of the following lesions: t(4;14), t(14;16), t(14;20), del (17p), or gain(1q). About 10% of patients in each arm had ultra-high-risk cytogenetics, which was defined as having more than one lesion.
Treatment
For induction, patients were randomized to KCRD, CRD, or CTD. All patients in the KCRD arm and patients in the CRD/CTD arms who achieved a partial response or better went straight to autologous transplant after induction. Nonresponders in the CTD and CRD arms received intensification with cyclophosphamide, bortezomib, and dexamethasone before transplant.
After transplant, all eligible patients were randomized to lenalidomide maintenance or observation. Patients were eligible for this randomization if they didn’t respond to induction, had progressive disease, or had previous or concurrent active malignancies.
The median follow-up was 34.5 months. The median number of induction cycles completed was 4 (range, 1-12) in the KCRD arm, 5 (range, 1-15) in the CRD arm, and 6 (range, 1-13) in the CTD arm.
Response
At the end of induction, the rate of very good partial response or better was 82.3% in the KCRD arm, 64.9% in the CRD arm, 52.8% in the CTD arm, and 58.9% in the CTD-CRD arms combined. The odds ratio for the KCRD group compared to the triplets combined was 4.35 (P less than .0001).
At 100 days after transplant, the rate of very good partial response or better was 91.9% in the KCRD arm, 82.1% in the CRD arm, 76.1% in the CTD arm, and 79.3% in the CTD-CRD arms combined. The odds ratio for the KCRD group compared to the triplets combined was 3.01 (P less than .0001).
KCRD produced a higher proportion of MRD-negative responses both before and after transplant. After induction, the rate of MRD-negative response was 11% in the CTD arm, 21% in the CRD arm, and 55% in the KCRD arm. After transplant, the rates were 51%, 49%, and 77%, respectively.