Amgen has asked the U.S. Food and Drug Administration to expand its approval of the bone-building therapy Prolia (denosumab) to include an additional osteoporosis condition.
The initial authorization covered men with metastatic prostate cancer who are at high risk of a fracture from the androgen deprivation therapy used to treat their disease. It also covered two osteoporosis conditions.
Amgen has submitted a supplemental biologics license application that asks the FDA to approve Prolia for glucocorticoid-induced osteoporosis, or GIOP.
One of the previous osteoporosis authorizations was for men with fragile bones who are at high risk of having a fracture. The other was for patients who were unable to tolerate other osteoporosis therapies or failed to respond to them.
The glucocorticoid medications that doctors prescribe for many inflammatory diseases can cause osteoporosis. Evidence suggests that the risk of a fracture increases by up to 75 percent in the first three months of glucocorticoid treatment. Bone mineral density not only declines during those months but continues dropping afterward, researchers have found.
“Glucocorticoid-induced osteoporosis can lead to weakened bones and debilitating fractures,” Dr. Sean E. Harper, an executive vice president at Amgen, said in a press release. “With this submission and future approval, we look forward to bringing the benefits of Prolia to patients living with this often overlooked and untreated form of osteoporosis.”
Amgen’s supplemental biologics license application is based on a Phase 3 clinical trial (NCT01575873) evaluating the safety and effectiveness of Prolia, compared with risedronate, in patients receiving glucocorticoid treatment.
The primary objective of the study was to see whether Prolia was better than risedronate at increasing bone mass in the lumbar spines of glucocorticoid-treated patients after 12 months. A secondary objective was to see whether Prolia did a better job at building bone mass than risedronate after more than a year’s treatment.
Prolia significantly outperformed risedronate at increasing bone mass in patients’ lumbar spines and hips at 12 months, the researchers said. This was true of both patients taking glucocorticoid therapy for a considerable period and those new to the therapy.
Adverse events were consistent with the safety profile of Prolia, the team said. The most common in men with osteoporosis were back pain, joint pain, and colds.
A little more than 3 percent of the men taking Prolia who had both prostate cancer and osteoporosis reported new malignancies, but researchers were unable to establish that the drug caused the new cancers.
Men with bone loss who were on androgen deprivation therapy for prostate cancer reported that their most common adverse reactions to Prolia were joint pain and back pain.
In men with non-metastatic prostate cancer, Prolia was associated with a greater incidence of cataracts.