Comparative efficacy and safety of bortezomib, thalidomide, and dexamethasone (VTd) without and with daratumumab (D-VTd) in CASSIOPEIA versus VTd in PETHEMA/GEM in transplant-eligible patients with newly diagnosed multiple myeloma, using propensity score matching.

ABSTRACT

Background: Traditional bortezomib, thalidomide, and dexamethasone (VTd) regimens for patients with newly diagnosed multiple myeloma (NDMM) include doses of thalidomide up to 200 mg/day (VTd-label). Clinical practice has evolved to use a lower dose (100 mg/day) to reduce toxicity (VTd-mod), which was evaluated in the phase III CASSIOPEIA study, without or with daratumumab (D-VTd; an anti-CD38 monoclonal antibody). We used propensity score matching to compare efficacy and safety for VTd-mod and D-VTd with VTd-label. Methods: Patient-level data for VTd-mod and D-VTd from CASSIOPEIA (NCT02541383) and data for VTd-label from the PETHEMA/GEM study (NCT00461747) were analyzed. Propensity scores were estimated using logistic regression, and nearest-neighbor matching procedure was used. Outcomes included overall survival (OS), progression-free survival (PFS), time to progression (TTP), postinduction and posttransplant responses, as well as rate of treatment discontinuation and grade 3/4 peripheral neuropathy. Results: VTd-mod was noninferior to VTd-label for OS, PFS, TTP, postinduction very good partial response or better (≥VGPR) and overall response rate (ORR). VTd-mod was significantly better for posttransplant ≥VGPR and ORR versus VTd-label. VTd-mod safety was not superior to VTd-label despite the lower thalidomide dose. D-VTd was significantly better than VTd-label for OS, PFS, TTP, postinduction and posttransplant ≥VGPR and ORR, and was noninferior to VTd-label for safety outcomes. Conclusions: In transplant-eligible patients with NDMM, D-VTd had superior efficacy compared with VTd-label. Despite a lower dose of thalidomide, VTd-mod was noninferior to VTd-label for safety and was significantly better for posttransplant ≥VGPR/ORR. These data further support the first-line use of daratumumab plus VTd.