Pfizer/Ligand's lasofoxifene reduces breast cancer risk in postmenopausal osteoporotic women

Lasofoxifene statistically reduced the overall risk of breast cancer, as well as estrogen receptor (ER) positive invasive breast cancer in postmenopausal women with low bone density, according to a study published on-line in The Journal of the National Cancer Institute.

Trade-named Fablyn and under development by US pharma behemoth Pfizer (NYSE: PFE) and Ligand (Nasdaq: LGND,) the drug has been approved in Europe for the treatment of osteoporosis in post-menopausal women at increased risk of fracture (The Pharma Letter March 30, 2009) but is still awaiting clearance in the USA.

Lasofoxifene is a selective estrogen receptor modulator (SERM) that, like tamoxifen, blocks the effects of estrogen in breast tissue. Another SERM, raloxifene, has been shown to reduce breast cancer risk. In the Postmenopausal Evaluation and Risk-Reduction with Lasofoxifene (PEARL) trial, a double-blind, placebo-controlled, randomized trial, 8556 postmenopausal women with low bone density and normal mammograms were randomly assigned to two doses of lasofoxifene - either 0.25mg or 0.50mg of it per day, or placebo.