In a Phase II clinical trial, denosumab produced high rates of tumor response among patients with recurrent or unresectable giant cell tumors of bone. These results were published in Lancet Oncology.
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.
Giant cell tumor of bone is a relatively uncommon type of bone tumor. In most patients it does not spread to other parts of the body, but it can cause extensive local destruction of bone if not effectively treated. These tumors tend to be rich in cells that express the RANK ligand, suggesting a possible role for denosumab in the treatment of this condition.
To evaluate the effect of denosumab among patients with giant cell tumor of bone, researchers conducted a Phase II clinical trial among 37 patients with recurrent or unresectable tumors. All patients were treated with denosumab.
The primary outcome of interest was tumor response. This was defined as at least 90% elimination of giant cells or no radiographic progression of the tumor. Tumor response was assessed at week 25 of the study.
- 86% of patients showed evidence of tumor response.
- Side effects were reported by 89% of patients. The most common side effects were pain in an extremity, back pain, and headache.
This study suggests that denosumab produces a high rate of tumor response in patients with giant cell tumor of bone. Additional studies of denosumab for the treatment of this condition are warranted.
Reference: Thomas D, Henshaw R, Skubitz K et al. Denosumab in patients with giant-cell tumor of bone: an open-label, phase 2 study. Lancet Oncology [early online publication]. February 10, 2010.