New Biologic Treatment Increases Bone Mass in Postmenopausal Women

Denosumab can increase bone mass in post menopausal women, according to research presented this week at the American College of Rheumatology Annual Scientific Meeting in San Francisco, Calif.

Postmenopausal women have markedly reduced levels of estrogen, leading to loss of bone and damage to bone quality. Currently, there are more than 10 million people—eight million of which are women—with osteoporosis who are susceptible to fractures. Those over the age of 50 are at greatest risk of developing osteoporosis and suffering related fractures. In this age group, one in two women will suffer an osteoporosis-related fracture at some point in her life.

Researchers recently compared the effectiveness and safety of denosumab, a biologic inhibitor of the activation of bone-resorbing osteoclasts that is administered just twice a year, with alendronate (FOSAMAX®), a drug commonly used in the prevention and treatment of osteoporosis in postmenopausal women.

They followed 1,189 postmenopausal women with low bone mass over one year’s time in a randomized double blind trial. Participants, with an average age of 64 years and whose average bone mineral density results in the lumbar spine were a T-score of 2.6—(the level at which a person is diagnosed with osteoporosis is -2.5)—were randomly assigned to one of two groups. The first group received a 60 mg injection of denosumab every six months and a weekly oral placebo. The second group received an injection of placebo every six months plus 70 mgs of alendronate, orally, each week. All participants took at least 500 mg of calcium and at least 400 mg of vitamin D daily.

Researchers evaluated changes in bone mass and substances found in the blood and urine that that reflect the rates of bone turnover, as well as drug safety over 12 months. Participants taking denosumab showed greater bone mass gains than those on alendronate. At the end of the study, more participants on denosumab had gained at least three percent of bone mass at the hip and lumbar spine than those on alendronate. In addition, denosumab suppressed serum markers of bone turnover, suggesting effective suppression of bone resorption.

Researchers found that side effects were similar between patients taking both denosumab and alendronate.

“The fact that bone density changes were greater than the most commonly used antiresorptive agent, alendronate, shows that denosumab is an effective agent,” explains Chad Deal, MD; head, Center for Osteoporosis and Metabolic Bone Disease, Cleveland Clinic, Cleveland, OH, and lead investigator in the study.

Patients should talk to their rheumatologists to determine their best course of treatment.

The ACR is an organization of and for physicians, health professionals, and scientists that advances rheumatology through programs of education, research, advocacy and practice support that foster excellence in the care of people with or at risk for arthritis and rheumatic and musculoskeletal diseases. For more information on the ACR’s annual meeting, see www.rheumatology.org/annual.