Selective estrogen receptor modulators in the treatment of osteoporosis: a review of the clinical evidence

The ideal selective estrogen receptor modulator will protect against fractures, prevent estrogen receptor-positive breast cancer, suppress vasomotor symptoms, offer cardiovascular protection, maintain vaginal and bladder health and prevent endometrial stimulation, with an acceptable safety and tolerability profile. Raloxifene is available in most countries and has been approved for the prevention of vertebral (not nonvertebral fractures) and estrogen receptor-positive breast cancer but do not offer cardiovascular protection. The development of arzoxifene was terminated because superiority compared with raloxifene could not be shown. Bazedoxifene has a profile very similar to raloxifene, but protects against nonvertebral fracture in patients at high risk of fracture and has superior endometrial protection that allows pairing with conjugated estrogen. Bazedoxifene is approved and available in some countries. Lasofoxifene prevents vertebral and nonvertebral fractures and protects against cardiovascular events and stroke without increasing the risk of endometrial cancer. Although it has been approved in the EU, it has not been approved in the USA and is not yet commercially available.