Phase II study of carfilzomib, thalidomide, and low-dose dexamethasone as induction and consolidation in newly diagnosed, transplant eligible patients with multiple myeloma; the Carthadex trial

T his is a phase II dose escalation trial of carfilzomib in combination with thalidomide and dexamethasone for induction and consolidation in transplant-eligible patients with newly diagnosed multiple myeloma (NDMM). The results of four dose levels are reported. Induction therapy consisted of four cycles of carfilzomib 20/27 mg/m(2) (n=50), 20/36 mg/m(2) (n=20), 20/45 mg/m(2) (n=21), and 20/56 mg/m(2) (n=20) on days 1, 2, 8, 9, 15, 16 of a 28-day cycle; thalidomide 200 mg on day 1 through 28 and dexamethasone 40 mg weekly. Induction therapy was followed by high-dose melphalan and autologous stem cell transplantation and consolidation therapy with four cycles of carfilzomib, thalidomide and dexamethasone in the same schedule except a lower dose of thalidomide (50 mg). Very good partial response rate or better and complete response rate or better after induction therapy were 65% and 18%, respectively, increasing to 86% and 63%, respectively, after consolidation therapy. In all cohorts combined, after a median follow up of 58.7 months, median progression-free survival was 58 months (95%CI: 45-67 months). Median overall survival was 83 months (95%CI: 83 months-not reached). Grade 3/4 adverse events consisted mainly of infections, respiratory disorders, skin and vascular disorders in 11%, 8%, 9%, and 9%, respectively. Grade 3 polyneuropathy was only reported in one patient. Cardiac events were limited: grade 3/4 in 5% of patients. Carfilzomib, thalidomide and dexamethasone as induction and consolidation treatment after high-dose melphalan and autologous stem cell transplantation is highly efficacious and safe in transplant-eligible patients with NDMM. This study was registered as #NTR2422 at http://www.trialregister.nl