 10. For females of child-bearing potential: a negative serum pregnancy test at screening and willing to use highly effective methods of birth control during the study period and for 60 days after the last dose of investigational product. Additionally they must agree to have pregnancy tests while on study medication. Highly effective methods of birth control are defined as those which result in a low failure rate i.e. less than 1 per year when used consistently and correctly, such as implants, injectables, combined oral contraceptives, some IUDs, sexual abstinence or vasectomized partner. Female patients will be considered to be of childbearing potential unless surgically sterilized by hysterectomy or bilateral tubal ligation, or post-menopausal for at least two years. 