Study: Treatment With Two Osteoporosis Drugs Better Than Either Drug Alone
Combination of denosumab and teriparatide achieves greatest increase in bone density (May 15)
A combination of two FDA-approved osteoporosis drugs with different mechanisms of action was found to increase bone density better than treatment with either drug alone in a small clinical trial. As reported in The Lancet, investigators at Massachusetts General Hospital found that treatment combining denosumab (Prolia; Amgen) and teriparatide (Forteo; Lilly USA) was superior to single-agent treatment in a 12-month trial in women with postmenopausal osteoporosis.
The authors note that additional study is required before their findings should be put into clinical practice.
“We found that giving both of these drugs together increased bone mineral density more than treatment with just one drug and more than has been reported for any currently available therapy for postmenopausal osteoporosis,” said corresponding author Benjamin Leder, MD. “This is particularly important since previous attempts to combine teriparatide with bisphosphonate drugs like Fosamax [alendronic acid; Merck] did not show any additional improvement.”
Bone density in young adults is maintained by a constant interaction between osteoclasts, which break down bone, and osteoblasts, which form new bone. After a woman goes through menopause, both processes accelerate, but the breakdown or resorption of bone increases more, leading to the overall loss of bone density and osteoporosis. While several types of drugs that increase bone density have been approved for the treatment of postmenopausal osteoporosis, none can reliably restore normal bone strength in most patients or eliminate the risk of osteoporosis-related fracture.
The investigators treated 100 postmenopausal women who had a high fracture risk, based on their bone density and other risk factors. During the 12-month study, one group received a subcutaneous 60-mg dose of denosumab every 6 months; another group self-administered daily 20-mcg injections of teriparatide; and the third group received both drugs at the same dosage schedules. Bone-density and blood tests were conducted at the outset of the study and after 3, 6, and 12 months of treatment. The final analysis included 94 participants who completed at least one follow-up visit.
The patients receiving both drugs had significantly better results than those receiving only one drug at several measured sites. For example, bone density measured at the lumbar spine increased 6.2% with teriparatide alone and 5.5% with denosumab, but combination treatment resulted in a 9.1% increase. Similar bone-density improvements were seen at the hip.
Source: Massachusetts General Hospital; May 15, 2013.