KRd Outperforms VRd in Newly Diagnosed Myeloma, Boosting PFS and Deepening Responses
But here’s where the story gets interesting: KRd shows a clear advantage in progression-free survival (PFS) and deeper responses compared with VRd, across patient groups, including those with higher-risk disease. This is based on interim COBRA trial results presented at the 2025 ASH meeting, which suggest KRd could redefine induction therapy for many patients with newly diagnosed multiple myeloma.
Carfilzomib/lenalidomide/dexamethasone (KRd) demonstrated a 43% reduction in the risk of progression or death versus bortezomib/lenalidomide/dexamethasone (VRd) in the intent-to-treat population, with a median follow-up of about 53 months. Specifically, the KRd group (n = 126) had a hazard ratio (HR) of 0.57 (95% CI, 0.37-0.88; P = .0095) compared with VRd (n = 124). Median PFS was not reached for KRd versus 48.8 months for VRd, signaling a meaningful delay in disease progression.
Across cytogenetic risk subgroups, KRd consistently trended toward benefit. In standard-risk disease (KRd n = 97 vs VRd n = 96), KRd significantly improved PFS (HR 0.59; 95% CI, 0.36-0.98; P = .04), with median PFS remaining not reached on KRd versus 48.8 months on VRd. In this subgroup, 27% of KRd patients progressed or died compared with 40% on VRd. In the high-risk cohort (KRd n = 29 vs VRd n = 28), KRd again favored outcomes (31% vs 48% progression or death). Median PFS was not reached with KRd vs 34.9 months for VRd (HR 0.52; 95% CI, 0.22-1.22; P = .12).
“COBRA shows superior efficacy of KRd versus VRd in newly diagnosed multiple myeloma, achieving both co-primary endpoints of MRD-negative CR at 12 months and PFS,” said presenting author Dominik Dytfeld, MD, PhD. KRd delivered deeper responses with higher complete response (CR) and MRD-negativity rates, and the PFS benefit was observed across cytogenetic risk categories. While KRd was associated with higher neutropenia and cardiac adverse events, it showed less neuropathy compared with VRd. These findings support further evaluation of KRd-based induction regimens in this setting.
Dytfeld, an associate professor at Poznan University of Medical Sciences (Poland) and founder/CEO of the Polish Myeloma Consortium, emphasized the potential of KRd to alter the standard of care for newly diagnosed myeloma and called for additional studies to confirm these results.
Trial design at a glance
- Type: Multicenter, randomized, open-label phase 3 study
- Population: Patients with newly diagnosed multiple myeloma and an IMWG Frailty Score < 2
- Arms: KRd (carfilzomib 56 mg/m² on days 1, 8, 15; lenalidomide 25 mg days 1–21; dexamethasone 40 mg weekly) vs VRd (bortezomib 1.3 mg/m² on days 1, 4, 8, 11; lenalidomide 25 mg days 1–14; dexamethasone 20 mg days 1–2, 4–5, 8–9, 11–12)
- Randomization: 1:1, stratified by cytogenetic risk (standard vs high risk) and prior venous thromboembolism
- Induction length: KRd up to 24 cycles; VRd up to 8 cycles
- Post-induction: Stem-cell collection for transplant-deferred approach; maintenance with lenalidomide
- Co-primary endpoints: MRD-negative CR at 12 months (sensitive to 10⁻⁵) and PFS
Safety snapshot
Both regimens produced high rates of adverse events (AEs), but with differing toxicity patterns. Grade 3 or higher AEs occurred in 73% of KRd patients and 62% of VRd patients; any-grade AEs were 96% and 94%, respectively. Discontinuation due to AEs occurred in 11% (KRd) vs 8% (VRd).
Neuropathy favored KRd (56% in VRd vs 17% in KRd for any grade), aligning with bortezomib’s known neuropathic risk. Cardiac AEs were more common with KRd (18% any grade; 6% grade ≥3) than VRd (10% any grade; 2% grade ≥3), reflecting carfilzomib’s cardiovascular risk profile. Infections were frequent in both arms but more so with KRd (75% any grade; 25% grade ≥3) vs VRd (60% any grade; 23% grade ≥3).
Transplant eligibility nuance
Among transplant-eligible patients, KRd reduced the risk of progression or death by 60% vs VRd (HR 0.40; 95% CI, 0.21-0.75; P = .003). Only 23% in the KRd arm progressed or died versus 45% in the VRd arm, with median PFS not reached for KRd and 40.1 months for VRd.
In contrast, among transplant-ineligible patients, outcomes were similar between KRd and VRd, with identical progression-or-death rates of 30% in both groups and non-significant PFS differences (HR 1.06; 95% CI, 0.21-0.75; P = .87).
Bottom line for clinicians and patients
KRd offers a meaningful advancement in PFS and MRD-depth of response for newly diagnosed multiple myeloma, including in standard-risk patients and, to a lesser extent, those with high-risk disease. The trade-offs include higher neutropenia and cardiac AEs, alongside a reduced neuropathy signal and higher infection rates. As with any regimen, individual patient factors—fitness for transplant, cardiovascular risk, and tolerance for potential neutropenia—should guide treatment choices.
Disclaimer and sources
- The COBRA trial (NCT03729804) is a phase 3 study comparing KRd vs VRd in newly diagnosed myeloma.
- Interim results were presented at the 2025 ASH Annual Meeting and published in Blood (2025) with supplementary clinical trial details available on ClinicalTrials.gov.
Would this KRd-based induction approach fit your patient population, or would VRd or another regimen remain preferable given individual risk factors and institutional experience? Share your thoughts and experiences in the comments.
