6. Female subjects have a negative serum pregnancy test at Screening. Female subjects of childbearing potential (i.e., not surgically sterile or 2 years postmenopausal) must have a negative pregnancy test at screening and a partner who is sterile, agree to abstinence, be practicing double barrier contraception or using an FDA approved contraceptive (e.g., licensed hormonal or barrier methods) for greater than 2 months prior to screening visit and commit to an acceptable form of birth control for the duration of the study and for 30 days after participation in the study.