A comparison of lenalidomide/dexamethasone versus cyclophosphamide/lenalidomide/dexamethasone versus cyclophosphamide/bortezomib/dexamethasone in newly diagnosed multiple myeloma

Novel agents are considered standard components of induction therapy for newly diagnosed patients with multiple myeloma. We retrospectively compared the results of three consecutive phase 2 clinical trials; RD (lenalidomide/dexamethasone, n=34), CRD (cyclophosphamide/lenalidomide/dexamethasone, n=53) and CyBorD (cyclophosphamide/bortezomib/dexamethasone, n=63) (N=150). Response rates after four cycles of treatment were: ≥near complete response (nCR), 12% vs. 2% vs. 41%, P<0·0001 and very good partial response or better, 35% vs. 30% vs. 65%, P=0·0003, respectively. With all cycles of therapy considered, ≥nCR was 35%, 15% and 41%, P=0·006. However, there is no evidence that one regimen produced superior progression-free survival (PFS) (median: 3·2 vs. 2·3 vs. 2·7years, P=0·11) or overall survival (3-year: 88% vs. 79% vs. 88%, P=0·23). Transplantation did not impact PFS (median: 2·7 vs. 2·3years, P=0·41) but was associated with improved OS (3-year: 93% vs. 75%, P≤0·001). High genetic risk patients (n=40) had earlier relapse despite lenalidomide or bortezomib (median: 2·1 vs. 2·7years, P=0·45). Grade 3/4 toxicities were least with CyBorD while CRD had most toxicity. In conclusion, CyBorD demonstrated superior responses and less frequent serious toxicity but more neuropathy when compared to RD and CRD. Importantly, 80% of patients treated with modern therapeutic approaches are alive at 4 years.