Safety and Pharmacokinetic Study of Dapivirine Gel (0.05%) Administered Rectally to HIV-1 Seronegative Adults

Inclusion Criteria: * Age of 18 - 45 years (inclusive) at Screening, verified per site standard operating procedure (SOP) * Able and willing to provide written informed consent * HIV-1/2 uninfected at Screening and Enrollment, per applicable algorithm in Appendix II of the protocol and willing to receive HIV test results * Able and willing to provide adequate locator information, as defined in site SOP * Available to return for all study visits and willing to comply with study participation requirements * In general good health at Screening and Enrollment, as determined by the site Investigator of Record (IoR) or designee * Per participant report, a history of consensual receptive anal intercourse (RAI) at least once in the past calendar year * Willing to not take part in other research studies involving drugs, medical devices, genital or rectal products, or vaccines for the duration of study participation, including the time between Screening and Enrollment * Willing to be sexually abstinent for 72 hours prior to each study visit, during the study product use periods and for 72 hours after biopsy collection. Note: See Criteria 12 and 13 for additional restrictions for female participants * Willing to abstain from inserting any non-study products into the rectum for 72 hours prior to each study visit and during the study product use periods. Note: See Criteria 12 and 13 for additional restrictions for female participants Females must also meet the following additional inclusion criteria to be eligible for study inclusion: * Women over the age of 21 (inclusive) must have documentation of a satisfactory Pap within the past 3 years prior to Enrollment consistent with Grade 0 according to the Female Genital Grading Table for Use in Microbicide Studies Addendum 1 (dated November 2007) to the DAIDS Table for Grading Adult and Pediatric Adverse Events, Corrected Version 2.1, July 2017, or satisfactory evaluation with no treatment required of Grade 1 or higher Pap result * Willing to be sexually abstinent for 72 hours prior to each study visit and during the study product use periods and for 7 days after biopsy collection * Willing to abstain from inserting any non-study products into the vagina for 72 hours prior to each study visit, during the study product use periods and for 7 days after biopsy collection * Willing to use an effective method of contraception for at least 30 days (inclusive) prior to Enrollment and intending to continue use of an effective method for the duration of study participation; effective methods include: hormonal methods (except contraceptive ring), intrauterine device (IUD), sterilization (of participant and/or partner, as defined in site SOPs), or sexually abstinent for 90 days prior to Screening Exclusion Criteria: * At Screening: * Hemoglobin Grade 1 or higher\* * Platelet count Grade 1 or higher\* * White blood count Grade 2 or higher\* * Serum creatinine greater than 1.3× the site laboratory upper limit of normal (ULN) * International normalized ratio (INR) greater than 1.5× the site laboratory ULN * Aspartate aminotransferase (AST) or alanine transaminase (ALT) Grade 1 or higher\* * Positive for hepatitis C antibody * Positive for hepatitis B surface antigen * History of inflammatory bowel disease by participant report * \*As per the Division of AIDS Table for Grading the Severity of Adult and Pediatric Adverse Events Corrected Version 2.1, July 2017 * Note: Otherwise eligible participants with an exclusionary test result (other than HIV, HBV or HCV) can be re-tested during the screening process. If a participant is re-tested and a non-exclusionary result is documented within 45 days of providing informed consent for screening, the participant may be enrolled. * Anticipated use of and/or unwillingness to abstain from the following medications during study participation: * Heparin, including Lovenox® * Warfarin * Plavix® (clopidogrel bisulfate) * Aspirin (greater than 81 mg) * Non-steroidal anti-inflammatory drugs (NSAIDS) * Any other drugs that are associated with increased likelihood of bleeding * CYP3A inducer(s) and/or inhibitor(s) as specified in the MTN-026 Study-Specific Procedures (SSP) Manual * Hormone-replacement therapy in tablet, injectable or gel form * Known adverse reaction to any of the components of the study products * Use of post-exposure prophylaxis (PEP) for potential HIV exposure within the 6 months prior to Enrollment * Use of pre-exposure prophylaxis (PrEP) for HIV prevention within the 6 months prior to Enrollment, and/or anticipated use during trial participation * Use of systemic immunomodulatory medications within the 6 months prior to Enrollment, and/or anticipated use during trial participation * RAI without a condom and/or penile-vaginal intercourse with a partner who is known to be HIV-positive in the past 6 months * Non-therapeutic injection drug use in the 12 months prior to Screening and Enrollment * Participation in research studies involving drugs, medical devices, genital or rectal products, or vaccines within 45 days of the Enrollment Visit * At Screening, participant report of treatment for an anogenital STI within the past 3 months * At Screening, participant-reported symptoms and/or clinical or laboratory diagnosis of active anorectal or reproductive tract infection requiring treatment per current World Health Organization (WHO) guidelines (http://www.who.int/hiv/pub/sti/pub6/en/) or symptomatic urinary tract infection (UTI). Infections requiring treatment include symptomatic Neisseria gonorrhea (GC), Chlamydia trachomatis (CT) infection, syphilis, active herpes simplex virus (HSV) lesions, anogenital sores or ulcers, or symptomatic genital warts, cervicitis, chancroid, pelvic inflammatory disease (PID), bacterial vaginosis (BV), symptomatic vaginal candidiasis, other vaginitis, trichomoniasis. Note: Otherwise eligible participants with an exclusionary UTI, BV and/or candida finding may be re-tested during the screening process. * At Enrollment, active anorectal or reproductive tract infection requiring treatment per current WHO guidelines (http://www.who.int/hiv/pub/sti/pub6/en/) or symptomatic urinary tract infection (UTI). Infections requiring treatment include symptomatic GC, CT, syphilis, active HSV lesions, anogenital sores or ulcers, symptomatic genital warts, bacterial vaginosis, symptomatic vaginal candidiasis, other vaginitis, trichomoniasis, chancroid, cervicitis and PID. Note: HSV-1 or HSV-2 seropositive diagnosis with no active lesions is permitted since treatment is not required * Has any other condition that, in the opinion of the IoR/designee, would preclude informed consent, make study participation unsafe, complicate interpretation of study outcome data, or otherwise interfere with achieving study objectives. Females who meet any of the following additional criteria will be excluded from the study: * Pregnant or breastfeeding at either Screening or Enrollment or intends to become pregnant or start breastfeeding during study participation. Note: A documented negative pregnancy test performed by study staff is required for inclusion; however, a self-reported pregnancy is adequate for exclusion from screening/enrollment into the study. * Last pregnancy outcome 90 days or less prior to Screening * Has had a hysterectomy * At Enrollment, has a clinically apparent Grade 1 or higher pelvic exam finding (observed by study clinician or designee) per the Female Genital Grading Table for Use in Microbicide Studies \[Addendum 1, Dated November 2007\]. Note: Cervical friability bleeding associated with speculum insertion and/or specimen collection judged to be within the range of normal according to the clinical judgment of the IoR/designee is considered expected non-menstrual bleeding and is not exclusionary.