Carfilzomib combined with lenalidomide and dexamethasone (KRd) as salvage therapy for multiple myeloma patients: italian, multicenter, retrospective clinical experience with 600 cases outside of controlled clinical trials

In combination with lenalidomide and dexamethasone (KRd), Carfilzomib has been approved for the treatment of relapsed and refractory multiple myeloma (RRMM) on ASPIRE trial. Efficacy and safety of the triplet are still the object of investigation by many groups to confirm ASPIRE results in the setting of RRMM treated in real-life who don't meet trial restrictive inclusion criteria. Therefore, we report a retrospective multicenter analysis of 600 RRMM patients treated with KRd between December 2015 and December 2018. The median age was 64 years (range 33-85), and the median number of previous therapies was two (range 1-11). After a median of 11 KRd cycles, the overall response rate was 79.9%. The median progression-free survival (PFS) was 22 months, and the 2-year probability of PFS was 47.6%. Creatinine clearance30 ml/min,1 line of previous therapy, and high-risk FISH were all associated with a poor prognosis in multivariate analysis. The median overall survival (OS) was 34.8 months; the 2-year probability of OS was 63.5%. At multivariate analysis, creatinine clearance30 ml/min,1 line of previous therapy, and high-risk FISH were significantly associated with poor prognosis. After a median follow-up of 16 months (range 1-50), 259 withdrew from therapy. The main discontinuation reason was progressive disease (81.8%). Seventy-four patients (12.3%) discontinued therapy for toxicity. The most frequent side effects were hematological (anemia 49.3%, neutropenia 42.7%, thrombocytopenia 42.5%) and cardiovascular (hypertension 14.5%, heart failure 2.5%, arrhythmias 3.6%). Our study confirms the safety and efficacy of KRd in the real-life setting of RRMM patients and encourages its use in clinical practice.