Lasoxifene reduces fractures in postmenopausal women with osteoporosis

January 01, 0001

Lasoxifene reduces fractures in postmenopausal women with osteoporosis

A new selective estrogen receptor modulator (SERM) medication has been developed. In this randomized trial by investigators from multiple countries 8556 women included who were between the ages of 59 and 80 years and had a bone mineral density T score of -2.5 or less at the femoral neck or spine. They were randomized to receive once-daily lasofoxifene (at a dose of either 0.25 mg or 0.5 mg) or placebo for 5 years. Primary end points were vertebral fractures, estrogen receptor (ER)-positive breast cancer, and nonvertebral fractures. Secondary end points included major coronary heart disease events and stroke.

They found: "Lasofoxifene at a dose of 0.5 mg per day, as compared with placebo, was associated with reduced risks of vertebral fracture (13.1 cases vs. 22.4 cases per 1000 person-years, hazard ratio 0.58), nonvertebral fracture (18.7 vs. 24.5 cases per 1000 person-years, hazard ratio 0.76), ER- positive breast cancer (0.3 vs. 1.7 cases per 1000 person-years, hazard ratio 0.19), coronary heart disease events (5.1 vs. 7.5 cases per 1000 person-years, hazard ratio 0.68), and stroke (2.5 vs. 3.9 cases per 1000 person-years, hazard ratio 0.64). Lasofoxifene at a dose of 0.25 mg per day, as compared with placebo, was associated with reduced risks of vertebral fracture (16.0 vs. 22.4 cases per 1000 person-years, hazard ratio 0.69) and stroke (2.4 vs. 3.9 cases per 1000 person-years, hazard ratio 0.61) Both the lower and higher doses, as compared with placebo, were associated with an increase in venous thromboembolic events (3.8 and 2.9 cases vs. 1.4 cases per 1000 person-years, hazard ratios 2.67 and 2.06, respectively). Endometrial cancer occurred in three women in the placebo group, two women in the lower-dose lasofoxifene group, and two women in the higher-dose lasofoxifene group. Rates of death per 1000 person-years were 5.1 in the placebo group, 7.0 in the lower-dose lasofoxifene group, and 5.7 in the higher-dose lasofoxifene group."

The authors concluded: "In postmenopausal women with osteoporosis, lasofoxifene at a dose of 0.5 mg per day was associated with reduced risks of nonvertebral and vertebral fractures, ER-positive breast cancer, coronary heart disease, and stroke but an increased risk of venous thromboembolic events."

Head-to-head comparison with raloxifene is warranted.

For the full abstract, click here.

N Engl J Med 362(8):686-696 25 February 2010 © 2010 to the Massachusetts Medical Society
Lasofoxifene in Postmenopausal Women with Osteoporosis. Steven R. Cummings, Kristine Ensrud, Pierre D. Delmas, et al.. Correspondence to: Dr. Cummings: [email protected]

Category: M. Musculoskeletal,X. Female Genital System, Breast,K. Keywords: lasofoxifene, selective estrogen receptor modulator, SERM, vertebral fracture, non-vertebral fracture, breast cancer, cororary heart disease events, stroke, endometrial cancer, mortality, randomized controlled trial, journal watch.
Synopsis edited by Dr Linda French, Toledo, Ohio. Posted on Global Family Doctor 16 March 2010

Pearls are an independent product of the Cochrane primary care group and are meant for educational use and not to guide clinical care.