This is a randomized, double-blind, placebo-controlled Phase 2 study designed to determine if amoxicillin will eradicate vaginal colonization/infection with Gardnerella vaginalis (GV) when administered to women who are colonized/infected with GV but have no clinical evidence of Bacterial Vaginosis (BV). The study will be conducted at 2 clinics in the United States: University of Alabama at Birmingham and Wake Forest University Health Sciences. Entire study duration is approximately 24 months and subject participation duration is approximately 22 days. Approximately 245 healthy adult females, 18 to 45 years of age will be screened to enroll approximately 98 participants to achieve 82 evaluable participants at the test of cure (ToC) visit. Participants will be enrolled and randomized to one of two groups, either amoxicillin (2 x 250 mg capsules by mouth twice daily for 7 days) or placebo. Women who are enrolled will be asked to return for one further visit, Visit 2 (Day 15 - 21), where a ToC will be completed. For those not enrolled, participation will end at their post screening follow up phone call. Women will be asked to use condoms during their participation. The primary objective is to determine if treatment with amoxicillin eradicates GV in women who are colonized/infected with GV but have no clinical evidence of BV.

This is a randomized, double-blind, placebo-controlled Phase 2 study designed to determine if amoxicillin will eradicate vaginal colonization/infection with Gardnerella vaginalis (GV) when administered to women who are colonized/infected with GV but have no clinical evidence of Bacterial Vaginosis (BV). The study will be conducted at 2 clinics in the United States: University of Alabama at Birmingham and Wake Forest University Health Sciences. Entire study duration is approximately 24 months and subject participation duration is approximately 22 days. Approximately 245 healthy adult females, 18 to 45 years of age will be screened to enroll approximately 98 participants to achieve 82 evaluable participants at the test of cure (ToC) visit. Women who consent to screening participation will undergo pelvic examination on entry and vaginal specimens collected for pH, whiff test and wet prep microscopy (Amsel criteria with the exception of evaluation of vaginal discharge), Nugent score, nucleic acid amplification test (NAAT) for trichomonas, quantitative NAAT for GV, and microbiome analysis. At Visit 1 (Enrollment - Day 1), women who tested positive for GV by NAAT, negative for BV by Nugent, and negative for trichomonas by NAAT will be enrolled and randomized to one of two groups, either amoxicillin (2 x 250 mg capsules by mouth twice daily for 7 days) or placebo. Women who are enrolled will be asked to return for one further visit, Visit 2 (Day 15 - 21), where a ToC will be completed (a pelvic exam completed with the same specimens taken as those at baseline with the exception of the trichomonas NAAT). For those not enrolled, participation will end at their post screening follow up phone call. Women will be asked to use condoms during their participation. The primary objective is to determine if treatment with amoxicillin eradicates GV in women who are colonized/infected with GV but have no clinical evidence of BV. The secondary objective is to evaluate the safety and tolerability of amoxicillin compared to placebo.

Inclusion Criteria:

1. Women ages 18-45, inclusive.

2. No evidence of vaginitis (yeast, trichomonas, and BV/abnormal vaginal flora) or other vaginal conditions which in the opinion of the investigator could be confounders*.

   *These causes will initially be detected by wet mount microscopy with trichomonas during the screening procedures and later confirmed by NAAT and BV/abnormal vaginal flora confirmed by Nugent scoring (Nugent score of 4-10).

3. Presence of GV detected by NAAT*.

   *Results of NAAT testing will be available prior to return for Enrollment visit.

4. Willing to use condoms during vaginal intercourse while participating in the study.

5. Not currently menstruating at screening visit.

6. Willing and able to provide written informed consent.

7. Negative urine pregnancy test on all participants of childbearing potential at study screening.

8. Participant must be of non-childbearing potential* or must be using highly effective birth control** to avoid becoming pregnant.

   *Non-childbearing potential is defined as being post-menopausal for at least 1 year, status after bilateral tubal ligation, or status after bilateral oophorectomy or status after hysterectomy.

   **In addition to the required use of condoms by the male partner during study participation, participants must agree to avoid becoming pregnant by using one of the following acceptable method of birth control for 30 days prior to screening and for the duration of the study:

   • Intrauterine contraceptive device; OR
   • Oral contraceptives; OR
   • Hormonal injections; OR
   • Hormonal implants; OR
   • Contraceptive patches; OR
   • Monogamous relationship with vasectomized partner; OR
   • Exclusively same-sex relationships; OR
   • Abstinence

9. Participant is not planning on taking antibiotics or using any intravaginal microbicides from the Screening visit through the Visit 2 Follow-up (TOC).

10. Participant is willing and able to cooperate to the extent and degree required by this protocol at the discretion of the investigator.

Exclusion Criteria:

1. Pregnant or nursing.
2. Allergic to penicillin, amoxicillin, cephalosporins, or other ß-lactam antibiotic.
3. Use of antibiotics in the past 14 days prior to screening visit.
4. HIV infected.
5. Women taking immunosuppressive agents.

7. History of renal impairment. 8. Use of any investigational drug within the past 30 days prior to screening. 9. Any other condition that, in the opinion of the investigator, would interfere with participation in the study.

All randomized subjects, receiving or not receiving the study product, are included in the baseline analysis population.

Unsolicited non-serious AEs and SAE were collected through Visit 2 (Day 15-21) after the first dose of treatment.

The safety data collection was targeted to collect serious and non-serious adverse events and congenital anomalies / birth defects as applicable that occurred after the first dose of treatment through Visit 2 (Day 15-21). Adverse events were captured by subject report/interview and clinical assessments, including clinician-conducted pelvic examination.