為期3年的隨機雙盲安慰劑控制試驗(Fracture REduction Evaluation of Denosumab in Osteoporosis every six Months [FREEDOM])納入了7808名年紀60-91歲的停經婦女，denosumab和骨質疏鬆婦女的脊椎、非脊椎與髖骨骨折發生率較低有關。
FDA Approves First-in-Class Injectable Osteoporosis Drug for Postmenopausal Women
By Laurie Barclay, MD
Medscape Medical News
June 2, 2010 — The US Food and Drug Administration (FDA) yesterday approved denosumab (Prolia; Amgen), an injectable drug for postmenopausal women with osteoporosis who are at high risk for fractures. This is the first new class of medicine for treating postmenopausal osteoporosis that has been approved in many years.
For postmenopausal osteoporosis, an injection of denosumab may be administered subcutaneously by a healthcare provider once every 6 months to reduce bone destruction and to improve bone mass and strength.
Women make up 80% of those with osteoporosis in the United States, and 1 of 2 women older than 50 years will have an osteoporotic fracture during their lifetime, according to the National Institute of Arthritis and Musculoskeletal and Skin Diseases.
"Due to its prevalence, osteoporosis is a serious concern to public health," Julie Beitz, MD, director of the FDA's Office of Drug Evaluation III, said in a news release. "The approval of Prolia provides another treatment option for postmenopausal women with osteoporosis who are susceptible to fractures."
Women with osteoporosis who are considered to be at high risk for fracture include those with previous osteoporotic fracture or multiple risk factors for fracture or those who have failed or are intolerant to other available treatment of osteoporosis.
In a 3-year, randomized, double-blind, placebo-controlled trial (Fracture REduction Evaluation of Denosumab in Osteoporosis every six Months [FREEDOM]) enrolling 7808 postmenopausal women aged 60 to 91 years, denosumab was associated with lower incidence of vertebral, nonvertebral, and hip fractures in women with osteoporosis.
The drug was administered as a 60-mg subcutaneous injection every 6 months vs placebo at 3 years. The trial resulted in a 68% reduction in vertebral fractures, 40% reduction in hip fractures, 20% reduction in nonvertebral fractures, and significant increases in bone density at the lumbar spine, total hip, and femoral neck.
Back pain, limb pain, musculoskeletal pain, hypercholesterolemia, and urinary bladder infections were the most common adverse effects reported with denosumab. Serious adverse events included hypocalcemia, serious skin and other infections, and dermatologic conditions including dermatitis, rashes, and eczema.
Denosumab is contraindicated in patients with hypocalcemia and may worsen particularly in patients with severe renal impairment. These patients should receive a supplement of calcium and vitamin D.
Because denosumab significantly suppresses bone turnover, it may increase risk for osteonecrosis of the jaw, atypical fractures, and delayed fracture healing. The FDA therefore requires a risk evaluation and mitigation strategy (REMS), including a medication guide for patients and information for healthcare providers regarding the risks and benefits of denosumab.
