Fulvestrant (Faslodex) is an estrogen receptor (ER) downregulator under development by AstraZeneca for the potential treatment of breast cancer [172191], [237518], [314472], [349551]. In March 2001, an NDA was filed in the US for the second-line treatment of advanced breast cancer in postmenopausal women who have progressed on prior hormonal therapy [403574], [434825]; in December 2001, AstraZeneca was expecting to launch the compound in the US in thefirst half of 2002 [431887]. In August 2001, late-stage clinical trials were ongoing in Japan for breast cancer [422343]. Fulvestrant also has potential in the treatment of other estrogen-responsive tumors, such as uterine tumors [178081]. By 1997, fulvestrant was in phase II trials for uterine fibroids [272162], and by February 1999, it was reported that phase II trials for endometriosis were ongoing [314472], [336599]. However, no development has been reported for these indications since that time. In October 2001, Morgan Stanley expected launch in 2002, with estimated sales of $80 million in 2002 rising to $208 million in 2007 [429700]. Analysts at Lehman Brothers predicted in December 2001, that the product has a 90% chance of making it to market in 2002, with peak sales potential in this year of $800 million [434768].