Purpose: This study examined real-world utilization patterns of bone-targeted agents (BTA) in patients with multiple myeloma (MM).
Methods: In this retrospective cohort study, adults with an MM diagnosis recorded in 2012-2014 were identified from electronic health records in the Oncology Services Comprehensive Electronic Records (OSCER) database. Patients received zoledronic acid (ZA) or pamidronate (PA) on/after first MM diagnosis recorded in the study period, had no BTA use in prior 6 months, and were followed through earliest of May 31, 2015 or last clinic visit. Patients with any solid tumor diagnosis were excluded. Time to BTA initiation, compliance (≥ 12 administrations in a year), switching, and non-persistence (switch or ≥ 90-day gap in therapy) were described by agent and follow-up period.
Results: Among 9,617 patients with MM, 3,735 (38.8%) received a BTA. Most patients (90.9%) received ZA, with first BTA use generally seen within 3 months of first observed MM diagnosis (ZA 76.1%, PA 75.1%). A minority of ZA (27.4%) and PA (23.0%) patients were compliant in Year 1, with lower compliance in Year 2 (19.8% and 15.6%, respectively). The median time to non-persistence was 16.2 (95% confidence interval [CI] 15.4-17.4) months for ZA and 13.8 (95% CI 11.5-15.4) months for PA. Persistence was 86% at 6 months and 34% at 24 months for ZA, and 77% and 30% for PA, respectively.
Conclusions: These results highlight the possibility of suboptimal prevention of skeletal-related events due to non-compliant dosing and non-persistence after patients initiate BTA therapy.
Keywords: Bone metastasis; Bone-targeted agents; Compliance; Multiple myeloma; Persistence.