6. Women must use a "highly effective" method of contraception throughout the trial. Highly effective methods of birth control are defined as those, alone or in combination, which result in a low failure rate (i.e. less than 1% per year) when used consistently and correctly. These methods include implants, injectables, oral contraceptives, some intrauterine contraceptive devices, sexual abstinence, tubal ligation or a vasectomized partner.