Patients with bone metastases from solid tumors initiating treatment with a bone-targeted agent in 2011: a descriptive analysis using oncology clinic data in the US.

PURPOSE: Three bone-targeted agents (BTAs) are approved in the USA for prevention of bone complications among solid tumor patients with bone metastases: two intravenous bisphosphonates (IV BP) (pamidronate and zoledronic acid), and one subcutaneous receptor activator of nuclear factor-kappaB (RANK) ligand inhibitor (denosumab). Using electronic medical record data from outpatient community and hospital-affiliated oncology clinics, we examined the characteristics of patients who initiated treatment with a BTA in 2011 and followed them for a maximum of 12 months.
METHODS: Adult patients with bone metastasis secondary to solid tumors newly treated with a BTA during 2011 were identified from the Oncology Services Comprehensive Electronic Records (OSCER) database. We examined patient characteristics at BTA initiation, treatment patterns, and compliance during a 12-month period. Sensitivity analyses were performed in a subgroup of patients who had confirmed 12 months of follow-up data.
RESULTS: Denosumab patients (N = 1,594) were older (65 % ≥65 years vs. 60 % ≥65 years), further along in their disease progression (time since bone metastasis diagnosis: 16 % ≥2 years vs. 10 % ≥2 years), less likely to switch BTA (overall: 6 vs. 14 %; subgroup: 8 vs. 19 %), and more compliant with treatment (overall: median doses of 7 vs. 4; subgroup: 11 vs. 8) compared to IV BP patients (N = 1,975). Findings were consistent across gender, age, tumor type, naïve, and transition strata.
CONCLUSIONS: Patients receiving denosumab and IV BPs may differ. Despite higher age and more advanced disease, patients treated with denosumab are more likely to stay on treatment and have better compliance.