(February 24, 2010 - Insidermedicine)

The investigational selective estrogen receptor modulators (SERM) lasofoxifene reduces the risk of fractures, breast cancer, heart disease, and stroke but increases the risk of venous thromboembolic events in postmenopausal women with osteoporosis, according to a trial published in the New England Journal of Medicine.

Here are some recommendations regarding the use of pharmacologic therapy for osteoporosis from the American College of Physicians:

•    offer pharmacologic treatment to men and women who have known osteoporosis and to those who have experienced fragility fractures

•    consider pharmacologic treatment for men and women who are at risk for developing osteoporosis

•    choose among pharmacologic treatment options for osteoporosis in men and women on the basis of an assessment of risk and benefits in individual patients

Researchers out of the California Pacific Medical Center Research Institute in San Francisco randomized 8,556 women between the ages 59 and 80 to treatment with once daily lasofoxifene 0.25 or 0.5 mg or a placebo for 5 years. All the women had a bone mineral density (BMD) T score of -2.5 or less at the femoral neck or spine.

Compared with placebo, lasofoxifene 0.5 mg was associated with a 42% reduced risk of vertebral fracture as well as a 24% reduced risk of non-vertebral fracture. In addition, the risk of estrogen receptor (ER) positive breast cancer was reduced by 81%, the risk of coronary heart disease (CHD) was reduced by 32%, and the risk of stroke by 36%. Both the lower and higher doses of lasofoxifene were associated with an increased risk of venous thromboembolic events. The drug did not increase the risk of endometrial cancer or hyperplasia.

Today's research suggests that the effects of lasofoxifene among postmenopausal women with osteoporosis may compare positively with other drugs used to treat osteoporosis, including other SERMS. Head-to-head trials are required for confirmation.