Utilization of intravenous bisphosphonates in patients with bone metastases secondary to breast, lung, or prostate cancer

PURPOSE: Cancer patients with bone metastases (BMets) are predisposed to skeletal complications. Bone-targeted therapies such as denosumab or intravenous bisphosphonates (IVBs) reduce the risk of these complications. This study characterized patterns of IVB use in these patients in the USA. METHODS: This was a retrospective, observational study using the Truven Health MarketScan® Commercial and Medicare databases (2002–2011). Subjects with ≥1 claims of diagnosis of breast, lung, or prostate cancer (BC, LC, or PC) and ≥1 claims of BMets diagnosis were included. The date of first BMet diagnosis claim was the “index date.” Key exclusion criteria were diagnosis of other primary cancer, receipt of IVB, or <6 months continuous enrollment pre-index. Cumulative incidence of treatment initiation, interruption, and discontinuation were estimated. Proportions of IVB claims with chemotherapy administered on the same day and with renal monitoring within 2 weeks prior were summarized. Multivariate regressions assessing factors associated with IVB initiation were conducted. RESULTS: Cumulative incidence of IVB initiation at 12 months post-index was greatest for BC followed by PC and LC, and it declined with age in all tumor types, e.g., in BC from 62 % at age <50 years to 47 % at age ≥75 years. At 12 months, IVB treatment interruption ranged from 16 % (LC) to 31 % (PC), with discontinuation ranging from 46 % (BC) to 83 % (LC). CONCLUSIONS: IVBs are used more frequently in patients with BMets secondary to BC than PC or LC. Many patients interrupt or discontinue IVB therapy within 12 months of initiation potentially impacting effectiveness.