Treatment Can Reduce Bone Turnover in Prostate Cancer

Study finds that denosumab reduces bone turnover better than bisphosphonates

24 july 2009-- Treatment of bone metastases in prostate cancer patients with denosumab, which blocks bone resorption, reduces bone turnover compared with bisphosphonates, according to a study in the August issue of the Journal of Urology.

As part of a Phase II trial, Karim Fizazi, M.D., from the Institut Gustave Roussy in Villejuif, France, and colleagues randomly assigned 50 patients with prostate cancer and bone metastases, despite the use of intravenous bisphosphonates, to continue receiving intravenous bisphosphonates every four weeks or to receive 180 mg subcutaneous denosumab (an antibody to block bone resorption) every four weeks or 180 mg every 12 weeks.

The researchers found that, at week 13, more denosumab-treated patients had urine N-telopeptide (a marker of bone turnover) less than 50 nM bone collagen equivalents per mM creatinine compared with bisphosphonate-treated patients (69 versus 19 percent), which continued at week 25 (69 versus 31 percent). Grade 4, asymptomatic, reversible hypophosphatemia was observed in one denosumab-treated patient.

"In patients with prostate cancer related bone metastases and increased urine N-telopeptide despite intravenous bisphosphonate treatment, denosumab normalized urine N-telopeptide levels more frequently than ongoing intravenous bisphosphonates," Fizazi and colleagues conclude.

The study was supported by Amgen Inc.; several authors reported financial or other relationships with pharmaceutical companies.

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