Denosumab More Effective Than Zometa in Prostate Cancer Patients with Bone Metastases
Among men with bone metastases from prostate cancer, the investigational drug denosumab was more effective than Zometa® (zoledronic acid) at delaying or preventing bone complications such as fracture. Results from this Phase III clinical trial will be submitted for presentation at an upcoming medical meeting.
Metastatic cancer refers to cancer that has spread to distant sites in the body. Several types of cancer—including prostate cancer—have a tendency to spread to the bone. Bone metastases can lead to serious problems such as fracture and spinal cord compression, and may require treatment with surgery or radiation therapy.
Bisphosphonate drugs such as Zometa are commonly used to reduce the risk of complications from bone metastases. Researchers continue, however, to explore new approaches to treatment.
Denosumab is an investigational drug that targets a protein known as the RANK ligand. This protein regulates the activity of osteoclasts (cells that break down bone). Denosumab has shown promising results in the management of patients with bone metastases as well as the management of bone loss due to cancer treatment.
To directly compare denosumab to Zometa among prostate cancer patients with bone metastases, researchers conducted a Phase III clinical trial. The study enrolled 1,901 patients with metastatic, hormone-refractory prostate cancer. Study participants were assigned to receive either denosumab or Zometa.
The objective of the study was to determine whether the occurrence of bone complications (“skeletal related events”) differed between the two study groups. The bone complications that were evaluated were fracture, radiation to the bone, surgery to the bone, and spinal cord compression.
- Patients treated with denosumab remained free of bone complications longer than patients treated with Zometa. Denosumab also reduced the rate of multiple bone complications.
- Overall survival and time to cancer progression were similar among patients treated with Zometa and patients treated with denosumab.
- Rates of adverse events were generally similar in the two study groups. Osteonecrosis of the jaw (an uncommon but serious side effect) occurred in 22 patients treated with denosumab and 12 patients treated with Zometa.
The results of this study suggest that denosumab may be more effective than Zometa at delaying or preventing skeletal complications in prostate cancer patients with bone metastases. Full results from this study will be submitted for presentation at an upcoming medical meeting.
Amgen News Release. Denosumab demonstrated superiority over Zometa in pivotal phase 3 head-to-head trial in prostate cancer patients with bone metastases. Available at: http://www.amgen.com/media/media_pr_detail.jsp?releaseID=1385163 Accessed February 9, 2010.
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