(February 24, 2010 - Insidermedicine)

The investigational drug known as lasofoxifene, which belongs to a class of drugs known as selective estrogen receptor modulators, or SERMs, can reduce the risk of fracture, breast cancer, heart disease, and stroke if taken by postmenopausal women with osteoporosis. The drug also increases the risk of blood clots, however. These are the main findings of a trial published in the New England Journal of Medicine.

Here is some information about osteoporosis:

•    It is a disease in which both bone mass is reduced and bone tissue deteriorates

•    It leads to increased bone fragility, resulting in an increased risk for fractures

•    About one in four women and one in eight men over the age of 50 have osteoporosis

Researchers from the California Pacific Medical Center Research Institute in San Francisco randomly assigned over 8,500 women aged 59 to 80 to treatment with a high dose of lasofoxifene, a low dose of this drug, or a placebo for 5 years. All the women in the trial had bone mineral density (BMD) low enough for them to be diagnosed with osteoporosis.

Compared with placebo, the women taking the high dose of lasofoxifene were less likely to have a fracture, either in the vertebra of their spine or elsewhere. They were also less likely to develop the type of breast cancer that is sensitive to estrogen, to experience a coronary event, or to have a stroke. With either dose of the drug, however, they were more likely than those on placebo to experience an event related to the development of blood clots in the veins.

Today's research suggests that the effects of the investigational drug lasofoxifene among postmenopausal women with osteoporosis may compare positively with other drugs used to treat osteoporosis, including other SERMs. It has yet to be compared head-to-head with such drugs, however.