Top-line data from a late-stage trial of Amgen's Prolia in osteoporosis patients receiving glucocorticoid therapy show that all primary and secondary targets being investigated were met.

According to the biotech giant, primary analysis of results indicates that the drug induced greater gains in bone mineral density (BMD) at 12 months versus its Actonel (risedronate).

In the study, Prolia 60mg subcutaneously every six months is being compared with oral Actonel 5mg daily in two patient subpopulations - those receiving continued glucocorticoid therapy and those starting the treatment.

Data showed that in patients receiving continuing glucocorticoid therapy Prolia led to greater gains in BMD compared with risedronate, both at the lumbar spine (4.4 percent versus 2.3 percent, respectively) and total hip (2.1 percent versus 0.6 percent, respectively).

In patients newly starting glucocorticoid treatment, Prolia also induced greater increases in BMD, both at the lumbar spine (3.8 percent vs. 0.8 percent, respectively) and total hip (1.7 percent vs. 0.2 percent, respectively).

On the safety side, both adverse events and serious adverse events were similar across treatment groups and consistent with the known safety profile of Prolia, the firm said.

Glucocorticoid-induced osteoporosis (GIOP) is caused by taking glucocorticoid medicines which are commonly used to treat inflammatory diseases. Within the first three months of treatment, patient fracture risk increases up to 75 percent, although BMD will continue to decline significantly in the months to follow.

"The impact of glucocorticoid therapy on bone strength is frequently underestimated, and often leads to increased bone loss and ultimately, a fracture," said Sean Harper, executive vice president of R&D at Amgen. "We are excited that these data support the potential for Prolia use in patients with glucocorticoid-induced osteoporosis, the most common drug-induced form of the disease".