Bortezomib-based therapy in non-transplant multiple myeloma patients: a retrospective cohort study from the FABIO project

INTRODUCTION: Randomized clinical trials showed that bortezomib, in addition to conventional chemotherapy, improves survival and disease progression in multiple myeloma (MM) patients not eligible for stem cell transplantation. The aim of this retrospective population-based cohort study is the evaluation of both clinical and economic profile of bortezomib-based versus conventional chemotherapy in daily clinical practice. METHODS: Healthcare utilization databases of six Italian regions were used to identify adult patients with non-transplant MM, who started a first-line therapy with bortezomib-based or conventional chemotherapy. Patients were matched by propensity score and were followed from treatment start until death, lost to follow-up or study end-point. Overall survival (OS) and restricted mean survival time (RMST) were estimated using the Kaplan–Meier method. Association between first-line treatment and risk of death was estimated by a conditional Cox proportional regression model. Average mean cumulative costs were estimated and compared between groups. RESULTS: In the period 2010–2016, 3509 non-transplant MM patients met the inclusion criteria, of which 1157 treated with bortezomib-based therapy were matched to 1826 treated with conventional chemotherapy. Median OS and RMST were 33.9 and 27.9 months, and 42.9 and 38.4 months, respectively, in the two treatment arms. Overall, these values corresponded to a HR of death of 0.79 (95% CI 0.71–0.89) over a time horizon of 84 months. Average cumulative cost were 83,839 € and 54,499 €, respectively, corresponding to an incremental cost-effectiveness ratio of 54,333 € per year of life gained, a cost coherent with the willingness-to-pay thresholds frequently adopted from Western countries. CONCLUSIONS: These data suggested that, in a large cohort of non-transplant MM patients treated outside the experimental setting, first-line treatment with bortezomib-based therapy was associated with a favourable effectiveness and cost-effectiveness profile.