Bone Abstracts

Objective: Zoledronic acid (Zol) has been demonstrated to be an effective therapy to treat postmenopausal osteoporosis (PMO) in Chinese women in a 12-month post-marketing observational study (ZOOM study). As an I.V. bisphosphonates, Zol are exclusively excreted via the kidneys. We present a report of the renal function and safety data of once-yearly Zol 5 mg treatment.

Subjects and methods: A total of 373 PMO patients from 30 different centers in China with baseline CCr >35 ml/min received a single 15-min infusion of Zol. Renal function (serum creatinine, creatinine clearance rate (CCr), and BUN) was tested at baseline, 6 and 12 month after therapy. Safety was assessed from adverse events and serious adverse events recorded by the investigators.

Results: Renal function assessment for all the patients showed that mean serum creatinine and BUN maintained 12 month after treatment (creatinine 62.64±14.59 vs 63.21±15.04 μmol/l and BUN 5.66±3.46 vs 5.44±3.18 μmol/l, respectively). Creatinine increase of more than 0.5 mg/dl compared to baseline was found in only one patient (0.38%) at 12 month. The baseline average CCr was 70.57±23.67 ml/min. During 1 year follow-up, CCr declined under 35 l/min in nine patients (9/257, 3.50%) with moderate renal impairment at baseline (CCr 35.52~ 47.63 ml/min). A total of 42 patients (11.26%) experienced adverse events (AEs). The most common AEs were fever (6.17%) and musculoskeletal pain (1.61%), while other AEs occurred below the ratio of 1%. Serious adverse events were reported in four cases, including three deaths due to pneumonia, lung cancer and gastric perforation, which were not considered by the Investigator to be drug related. 81.01% of all enrolled patients were willing to continue the Zol treatment.

Conclusion: Once yearly zoledronic acid administration was associated with a good safety profile and generally well tolerated in Chinese PMO patients.