The Prolia brand of denosumab has been approved as a treatment for bone loss in people receiving hormone ablation therapy for prostate or breast cancer, according to a statement from Amgen, the manufacturer.
The approved indications are for increasing bone mass in women at high risk for fracture on adjuvant aromatase inhibitor therapy for breast cancer and in men at high risk for fracture on androgen deprivation therapy (ADT) for nonmetastatic prostate cancer, the company's statement said.
Denosumab, a RANK ligand inhibitor, was first approved in June 2010 for treating postmenopausal women with osteoporosis at high risk of fracture and is marketed as Prolia for this indication. Prolia is administered in a subcutaneous injection once every 6 months, at a dose of 60 mg.
In November 2010, denosumab was also approved for preventing skeletal-related events in patients with bone metastases from solid tumors. It is marketed as Xgeva and administered more frequently at a higher dose for this indication.
Approval of the new indications for Prolia was based on phase III studies of these two groups of patients, according to Amgen. In an international study of almost 1,500 men with nonmetastatic prostate cancer who were being treated with ADT, bone mineral density at the lumbar spine after 2 years of treatment was significantly higher among men who had received denosumab compared with those who received placebo. After 3 years of treatment, the incidence of new vertebral fractures was 1.5% among those treated with denosumab, compared with 3.9% for those on placebo, a risk reduction of 62%, the company said.
And in a study of 252 postmenopausal women with breast cancer under treatment with an aromatase inhibitor, bone mineral density at the lumbar spine was significantly higher among those treated with denosumab compared with those on placebo after 12 months of treatment, according to the statement.
Arthralgia and back pain were the most common adverse events associated with treatment in these two groups of patients. Hypocalcemia was also reported; denosumab is contraindicated in people with hypocalcemia. Treatment was associated with cataract events in men in the prostate cancer trial.
In the European Union, denosumab is approved for the osteoporosis indication as well as the prostate cancer indication just approved in the United States, according to Amgen.