A Drug-drug Interaction Study to Investigate the Effect of Coadministration of EDP-305 on the PK of a Combined Oral Contraceptive in Healthy Female Subjects

Inclusion Criteria: * Females of childbearing potential, 18 to 45 years of age, inclusive. Follicle-stimulating hormone levels may be used to confirm premenopausal status, including females who have had a hysterectomy with ovaries still intact. Women who otherwise meet inclusion criteria and who have had tubal ligation, tubal occlusion, or bilateral salpingectomy will be allowed. * Body mass index between 18.0 and 32.0 kg/m2, inclusive. * In good health, determined by no clinically significant findings from medical history, physical examination, 12 lead ECG, vital signs measurements, and clinical laboratory evaluations at Screening and Day -1 of the Lead-in Period * Must not be pregnant or lactating, and must agree to use contraception * Subjects must have documentation of normal results of up-to-date cervical cancer screening as specified in the American College of Obstetricians and Gynecologists guidelines: 1. Women aged \< 21 years: no documentation required 2. Women aged 21 to 29: normal Pap smear test result within previous 3 years 3. Women aged 30 to 45: normal Pap smear test result and negative high-risk human papilloma virus test within previous 5 years, OR normal Pap smear test result within previous 3 years If documented results are not available at Screening, the subject must provide documentation of normal results prior to Day -1 of the Lead-in Period. * Able to comprehend and willing to sign an ICF. * Willing and able to adhere to assessments, prohibitions, and restrictions as described in this protocol. Exclusion Criteria: * Significant history or clinical manifestation of any metabolic, allergic, dermatological, hepatic, renal, hematological, pulmonary, cardiovascular, GI, neurological, respiratory, endocrine, or psychiatric disorder, as determined by the Investigator (or designee). * Are pregnant, breastfeeding, or are planning to conceive during the study. * Have been administered injectable contraceptives within 12 months prior to Day -1 of the Lead in Period, or had exposure to a hormonal intrauterine device or topical controlled delivery contraceptives (patch) within 3 months prior to Day -1 of the Lead-in Period.