 - Pregnancy is to be avoided during the study. Women who have not had a hysterectomy or oophorectomy must have a negative urine pregnancy test result at screening. Women of childbearing potential will be allowed to participate if they have undergone tubal ligation, or use one of the following types of contraception: properly used condom or diaphragm, oral contraceptives, hormonal implant, or intrauterine device IUD. Sexual abstinence may constitute an acceptable birth control method for this study with investigator approval. Women with male partners who have had a successful vasectomy more than one year of unprotected sexual intercourse without pregnancy are not required to use additional birth control methods as long as the relationship remains exclusive, and the woman agrees to use an approved contraception method with any other male partner. Questions regarding individual patient contraceptive practices should be directed to the Principal Investigator. 