Among patients with multiple myeloma or bone metastases from breast cancer, prostate cancer, or other solid tumors, denosumab was more effective than Zometa® (zoledronic acid) at delaying or preventing bone complications such as fracture. Results from an integrated analysis of Phase III clinical trials were presented at the 35th European Society for Medical Oncology (ESMO) Congress.
Metastatic cancer refers to cancer that has spread to distant sites in the body. Several types of cancer—including breast and 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.
In multiple myeloma, plasma cells infiltrate the bone marrow, spreading into the cavities of all the large bones of the body. In a majority of patients with multiple myeloma, the bones develop multiple holes, referred to as osteolytic lesions, that cause the bones to be fragile and subject to fracture.
Zometa is a bisphosphonate drug that is commonly used to reduce the risk of bone complications from bone metastases or multiple myeloma. Researchers continue, however, to explore new approaches to treatment.
Denosumab is a drug that targets a protein known as the RANK ligand. This protein regulates the activity of osteoclasts (cells that break down bone). Denosumab has been approved for the treatment of postmenopausal osteoporosis and has also shown promising results in the management of bone metastases and treatment-related bone loss.
The current analysis was based on information from three Phase III clinical trials that directly compared denosumab to Zometa among patients with bone metastases or multiple myeloma. Together, the studies enrolled more than 5,700 patients. The studies assessed the frequency and timing of bone complications such as 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. Median time to first on-study bone complication was 27.7 months among patients treated with denosumab compared with 19.5 months among patients treated with Zometa.
- Overall survival and time to cancer progression were similar among patients treated with Zometa and patients treated with denosumab.
- Osteonecrosis of the jaw (an uncommon but serious side effect) occurred in 1.8% of patients treated with denosumab and 1.3% of patients treated with Zometa. This difference between study groups was not statistically significant, suggesting that it could have occurred by chance alone.
These results suggest that denosumab may be more effective than Zometa at delaying or preventing skeletal complications in patients with bone metastases or multiple myeloma.
 Lipton A, Siena S, Rader M et al. Comparison of denosumab versus zoledronic acid (ZA) for treatment of bone metastases in advanced cancer patients: An integrated analysis of 3 pivotal trials. Presented at the 35th European Society for Medical Oncology (ESMO) Congress, Milan, Italy, October 8-12, 2010. Abstract 1249P.
 Cleeland CS, Patrick DL, Fallowfield L et al. Effects of denosumab vs zoledronic acid (ZA) on pain in patients (pts) with advanced cancer and bone metastases: An integrated analysis of 3 pivotal trials. Presented at the 35th European Society for Medical Oncology (ESMO) Congress, Milan, Italy, October 8-12, 2010. Abstract 1248P.