Retrospective Database Analysis of the Effect of Zoledronic Acid (ZOL) On Skeletal-Related Events (SREs) in Patients (Patients) with Multiple Myeloma (MM).

Abstract 3881 Poster Board III-817 Background For MM patients with malignant bone lesions (BM), SREs including pathologic fracture, spinal cord compression, hypercalcemia of malignancy, and radiotherapy and/or surgery to bone are associated with significant morbidity and mortality and reduced quality of life. ZOL is an IV bisphosphonate (BP) proven to reduce and delay incidence of SREs in several tumor types. This study was designed to assess the benefit of long-term ZOL use in a real-life setting. Methods Claims-based analysis of commercial and Medicare data from a large US managed care plan and a 45 health-plan database was used to evaluate SRE rates, time from BM to 1st SRE, and mortality in patients treated with ZOL or no IV BP therapy. Patients older than 18 years with MM and BM diagnosed between Jan 2001 and Dec 2006 were included. Treatment Persistency was defined as the absence of a >45 day gap between ZOL administrations. Continuous enrollment in the health plan for 6 months before and no prior evidence of BM or IV BP use were required. When assessing mortality, patients with a date of death less than 30 days following index date were excluded. Patients were followed until they disenrolled from the plan or to the end of the study's follow-up period. In this study, SREs were defined as evidence of pathologic fracture, spinal cord compression, and radiotherapy and/or surgery to bone. Results The study sample included 1,655 Patients with a mean age of 61.7 ± 11.9 years; approx. 64% were treated with ZOL and 36% with no IV BP. Incidences of SREs and mortality rates were both greater in the no IV BP group (incidence rate ratio [IRR] = 1.58; p-value<0.001 and mortality rate = 1.71; p-value=0.0234) vs. the ZOL groups. Longer persistency with ZOL was associated with a lower risks of first SRE compared with no IV BP (trend test p-value=0.0025) [TABLE 1]. Conclusions This study showed that in MM Patients with BM, ZOL use was associated with a lower risk of SREs, including fractures, and lower mortality rates. In addition, longer persistence was found to be associated with lower risk of SRE. Disclosures: Kaura: Novartis: Employment, Equity Ownership. Perez:Novartis: Employment, Equity Ownership.