Carfilzomib-Lenalidomide-Dexamethasone (KRd) Induction-Autologous Transplant (ASCT)-Krd Consolidation Vs KRd 12 Cycles Vs Carfilzomib-Cyclophosphamide-Dexamethasone (KCd) Induction-ASCT-KCd Consolidation: Analysis of the Randomized Forte Trial in Newly Diagnosed Multiple Myeloma (NDMM)

Background: Proteasome inhibitor (PI)-based induction and consolidation proved to be effective in newly diagnosed multiple myeloma (NDMM) patients (pts) eligible for melphalan 200 mg/m2-autologous stem cell transplant (MEL200-ASCT). High response rates have been reported with the second-generation PI Carfilzomib in combination with Lenalidomide-dexamethasone (KRd) or Cyclophosphamide-dexamethasone (KCd). Aims: The primary aim was to evaluate the efficacy and safety of KRd induction-ASCT-KRd consolidation (KRd-ASCT-KRd) vs 12 cycles of KRd (KRd12) vs KCd induction-ASCT-KCd consolidation (KCd-ASCT-KCd). Methods: NDMM pts ≤65 years were randomized (1:1:1; stratification ISS and age) to: KRd-ASCT-KRd: 4 28-day cycles with KRd induction (Carfilzomib 20/36 mg/m2 IV days 1,2,8,9,15,16; Lenalidomide 25 mg days 1-21; dexamethasone 20 mg days 1,2,8,9,15,16) followed by MEL200-ASCT and 4 KRd consolidation cycles; KRd12: 12 KRd cycles; KCd-ASCT-KCd: 4 28-day induction cycles with KCd (Carfilzomib 20/36 mg/m2 IV days 1,2,8,9,15,16; Cyclophosphamide 300 mg/m2 days 1,8,15; dexamethasone 20 mg days 1,2,8,9,15,16) followed by MEL200-ASCT and 4 KCd consolidation cycles. Thereafter, pts were randomized to maintenance with Lenalidomide alone or plus Carfilzomib. Centralized minimal residual disease (MRD) evaluation - 8-color second generation flow cytometry, sensitivity 10-5 - was performed in pts achieving ≥very good partial response (VGPR). Endpoints were pre-maintenance stringent complete response (sCR) and MRD negativity in intention-to-treat (ITT) analysis. Data cut-off was May 30, 2018. Results: 474 NDMM pts were randomized (KRd-ASCT-KRd, n=158; KRd12, n=157; KCd-ASCT-KCd, n=159) and analyzed. Pts characteristics were well balanced. Median follow-up was 20 months. Depth of response improved during treatment (Figure). By ITT analysis, rates of pre-maintenance sCR was similar between KRd-ASCT-KRd (41%) and KRd12 (42%), and significantly higher than with KCd-ASCT-KCd (30%; P value KRd-ASCT-KRd vs KCd-ASCT-KCd=0.047; P value KRd12 vs KCd-ASCT-KCd=0.028). Similarly, rate of ≥CR was 49% with KRd-ASCT-KRd, 52% with KRd12 and 38% with KCd-ASCT-KCd (P value KRd-ASCT-KRd vs KCd-ASCT-KCd=0.041; P value KRd12 vs KCd-ASCT-KCd=0.014) and rate of ≥CR+unconfirmed CR (missing immunofixation confirmation) raised to 60% vs 63% vs 46% in the 3 groups, respectively; rate of ≥VGPR was 88% with KRd-ASCT-KRd, 86% with KRd12 and 74% with KCd-ASCT-KCd (P value KRd-ASCT-KRd vs KCd-ASCT-KCd=0.002; P value KRd12 vs KCd-ASCT-KCd=0.008). In multivariate analysis, the main factor affecting probability of achieving ≥VGPR, ≥CR or sCR was treatment with KRd-ASCT-KRd or KRd12 vs KCd, with no significant impact of ISS Stage or FISH abnormalities. In ITT analysis (MRD missing [31/395 VGPR pts, 8%] and