Treatment patterns of bone-targeted agents for the prevention of skeletal-related events in multiple myeloma in Bulgaria: a cross-sectional chart review study

Abstract

Background: Bone disease (MBD) is common in patients with multiple myeloma (MM) and ~80% are already affected at diagnosis. MBD increases the risk of skeletal-related events (SREs) and the use of bone-targeted agents (BTAs) is recommended for their prevention and treatment. Methods: This study retrospectively analyzed electronic health records of adults with MBD treated in real-world practice in any of eight hematology clinics in Bulgaria. The study assessed patients’ demographics and clinical characteristics, BTA treatment patterns and pain management, and estimated the incidence of SREs and osteonecrosis of the jaw (ONJ). Results: The study included 732 patients (denosumab: 177; zoledronic acid: 440; zoledronic acid and denosumab sequentially: 115). In 83%, 84%, and 84% of patients, respectively, the first recorded therapy contained a BTA either alone or in combination with an anti-myeloma therapy. The median (Q1, Q3) duration of BTA administration was longer in patients receiving both BTAs sequentially (zoledronic acid: 84 [24, 157] days; denosumab: 60 [0, 197] days). BTAs were prescribed mostly in preventive intent: only 22%, 16%, and 30%, respectively, had experienced previous SREs. While receiving BTAs, new SREs occurred in 9%, 7%, and 9%, respectively. Seven cases of ONJ were identified but only one occurred during BTA use (in the zoledronic acid cohort). Conclusions: Patients with MM are at very high risk of SREs. When receiving BTAs with a preventive intent, only a minority (<10%) experienced an SRE. These data suggest that preventive BTA use, effectively reduces the risk of SREs in real-life clinical practice.