Zoledronic Acid Effective as Treatment for Bone Complications in Prostate Cancer Patients

The bisphosphonatezoledronic acid (Zometa) iseffective in the treatment of skeletal-relatedevents from bone metastases in prostate cancer patients, according to datapresented at the 97th annual meeting of the American Urological Association.Patients with advanced prostate cancer are at high risk for bone complications,including bone pain, pathologic fractures, need for radiation or surgery tobone, and spinal cord compression. This study marks the first time abisphosphonate has demonstrated efficacy in the treatment of bone metastases inthis patient population.

"Bone metastases can result in debilitating pain,fractures, and compression of the spine and are a significant problem forpatients with advanced prostate cancer. Until now, there were few effectivetherapies available for these patients," said Fred Saad, md, associateprofessor of urology and director of urologic oncology at the Montreal CancerInstitute, University of Montreal. "Zometa represents a significant advancein the overall treatment of advanced prostate cancer patients."

The study was designed to investigate the efficacy ofzoledronic acid in patients with bone complications resulting from prostatecancer, particularly with respect to reducing the proportion of patients withskeletal-related events and delaying the time to the first such event. A totalof 643 patients who progressed through hormonal therapy with at least one bonemetastasis participated in the multicenter, randomized, placebo-controlledtrial. The final analysis was based on an evaluation of zoledronic acid, 4 mg in100 mL of solution, compared to placebo, at an infusion rate of 15 minutes,given every 3 weeks for 15 months.

Improvements Evident at 15 Months

The 15-month data demonstrated that 25% fewer patients taking4 mg of zoledronic acid experienced any skeletal-related event compared topatients taking placebo (33% vs 44%, P = .021). The data alsodemonstrated that fewer patients taking zoledronic acid had a pathologicfracture compared to patients taking placebo (13% vs 22%, P = .015).

Patients taking zoledronic acid showed a slower rate of pain progressioncompared with placebo. All patients experienced a mean increase from baseline incomposite Brief Pain Inventory pain scores over time. However, the increaseswere lower at every time point for patients treated with zoledronic acidcompared with placebo (and were statistically significant at months 3 and 9).