2. Women of child-bearing potential unless infertile (including surgically sterile) or practicing effective contraception (e.g., abstinence, IUD or barrier method plus hormonal method). These patients must have a negative serum B-HCG test at the Initial Screening Visit and a negative urine pregnancy test at the Baseline Visit. These patients must also be willing to remain on their current form of contraception for the duration of the study. Postmenopausal women may be recruited but must be amenorrhoeic for at least 1 year to be considered of non-child bearing potential.