PROJECT 2 - ABSTRACT Our team developed a non-hormonal, on-demand, female-controlled, non-surfactant, contraceptive vaginal film that releases an innovative human contraceptive antibody (HCA). The HCA film could fill an important gap in the current contraceptive method mix for women worldwide. Project 2 will conduct two United States Food and Drug Administration (US FDA) required clinical studies, which will build upon progress made in our ongoing award (NICHD P50 HD096957). Under an exploratory investigational new drug protocol, Eastern Virginia Medical School (EVMS) (PI Thurman) is currently conducting the first-in-human, post coital testing (PCT), pharmacokinetic (PK) and safety study (ClinicalTrials.gov #NCT04731818) of a single, 20 mg dose of the HCA film, inserted 30 minutes prior to unprotected intercourse at peak ovulation. Current data support that the 20 mg film is safe and acceptable for both the woman and her male sexual partner. All product use PCT data thus far support contraceptive efficacy, showing less than 5 progressively motile sperm (PMS) per high powered field (hpf) in ovulatory cervical mucus (mean = 0.05 PMS/hpf, n= 7 women). Specific Aim 1: The operations planning, technical content generation, site training, and local regulatory filings to prepare for the next clinical trials will begin immediately. Specific Aim 2: We will conduct a Phase I, Placebo-Controlled, Double-Blinded, Randomized, Interventional, Safety and PK study of Single and Multiple Dosings of the HCA 20 mg film at EVMS. This study will include FDA required safety assessments and also innovative assays which quantify sub-clinical changes relevant to topical vaginal product safety. Specific Aim 3: We will conduct a Phase 2a, multi-center [EVMS and University of Texas at San Antonio (UT Health)], dose finding (5 mg vs. 10 mg vs. 20 mg), PK study of the HCA film. We will use an adaptive study design, starting with the lowest dose. The PCT endpoint will be used as an in vivo surrogate of contraceptive efficacy. We will examine a range of pre-coital dosing time frames (15 min – 4 hours) to assure that this product fits in to the lifestyles of future end users. Project 2 will be closely integrated with Project 1 and its lead institution, ZabBio, who will provide the active and placebo films, and monitoring and auditing of the clinical studies. Likewise, Project 2 will interface closely with the Administrative Core at Boston University, which will provide data management and statistical support. Clinical samples from Project 2 studies will be analyzed by Project 3; the Boston University lab will use innovative assays to quantify the effect of 14- day dosing on sub-clinical mucosal safety signals (epithelial barrier quality, sub-clinical pro-inflammatory proteins) and to describe any changes in the vaginal microbiome with film use. Samples from both clinical studies will be analyzed by Project 3 to confirm that HCA film use does not elicit the development of endogen...