Oporia formulated by using Lasofoxifene is the first of three late stage SERM products that are under development by Ligand Pharmaceuticals which has been submitted for the authentic recognition in the United States. Oporia – Lasofoxifene is the selective estrogen receptor modulator-SERM, produced under the joint development program between Pfizer and Ligand Pharmaceuticals. During August 2004, Pfizer submitted the NDA to the U.S. FDA for the use of Oporia – Lasofoxifene as the preventive medication for osteoporosis during the post menopausal women. Pfizer came to know about the rejection of NDA for Oporia – Lasofoxifene as the preventive therapy for the osteoporosis by the U.S. FDA, during September 2005 

Osteoporosis is the ailment caused form the loss of bony tissues that makes the bones fragile and prone to fracture. This condition is common in the post menopausal women who have reported the rapid fall of the estrogen levels after the cessation of menopause. The treatment provided at this juncture is to avert osteoporosis from developing besides, avoiding bone loss for minimizing the risk of osteoporotic fractures. The anti-restorative drugs play the vital role in the treatment and avoidance of osteoporosis and incorporate: the hormone replacement therapy – HRT; Biphosphonates and Oestrogen analogues or SERMs.

SERMs are the latest approved class of anti-restorative drugs which imitate the effects of oestrogen in several tissues like bones; whereas in the others they act as anti-oestrogen and obstruct the useless oestrogenic affects on uterine and the breast tissues. However, the perfect SERM should accomplish the subsequent criteria: guard against the bone loss minimizing the risk of bone fractures; guard against the heart attacks and strokes; not provoking the endometrial bleeding; not enhance the uterine cancer risk; minimize the risk of breast cancer development and remain safer on the extended use.