Real-world effectiveness and safety of daratumumab, bortezomib and dexamethasone in relapsed/refractory multiple myeloma in Slovakia.

Real-world data on regimens for relapsed/refractory multiple myeloma (RRMM) are limited. Daratumumab in combination with bortezomib and dexamethasone is a promising new treatment. The aim of this analysis was to assess the outcomes of daratumumab-bortezomib-dexamethasone (DVd) combination for the treatment of patients with RRMM in a real-world setting. All consecutive RRMM patients who received at least two cycles of DVd treatment between December 2016 and July 2020 were identified. We analyzed the clinical characteristics and survival of 47 patients treated at 7 Slovak centers outside of the clinical trials. The median age was 65 years (range, 35 to 83). The median (range) number of lines of therapy per patient was 3 (2-6). All patients were previously exposed to PIs (proteasome inhibitors) and IMIDs (immunomodulatory drugs), the majority of patients (70.2%) had double refractory (IMIDs and PI) disease and 72.3% of patients were refractory to their last therapy. Most patients presented with high-risk characteristics, including 25.6% adverse cytogenetics and 25.5% extramedullary disease. The majority of patients responded with an overall response rate of 78%, we found complete response in 3, very good partial response in 22, partial response in 12, minor response or stable disease in 9, and progressive disease in 1 patient. After a median follow-up period of 8 months, the median progression-free survival was 10 months. There was a longer progression-free survival in those with 2 vs. >2 prior treatments, with equally good effectivity in standard-risk and high-risk cytogenetic groups. The adverse events were usually mild, none leading to permanent drug interruptions. Daratumumab-bortezomib-based combinations are efficacious and safe regimens in RRMM patients in the real-world setting. This is the first analysis in Slovakia addressing the DVd combination outside of the clinical trial setting.