Completed

Phase II/IIb Safety and Effectiveness Study of the Vaginal Microbicides BufferGel and 0.5% PRO 2000/5 Gel (P) for the Prevention of HIV Infection in Women

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What is being tested

BufferGel

+ PRO 2000/5 Gel

+ Placebo gel

Drug
Who is being recruted

Blood-Borne Infections+15

+ Urogenital Diseases

+ Genital Diseases

Over 18 Years
See all eligibility criteria
How is the trial designed

Prevention Study

Placebo-ControlledPhase 2
Interventional
Study Start: January 2005
See protocol details

Summary

Principal SponsorNational Institute of Allergy and Infectious Diseases (NIAID)
Last updated: January 18, 2026
Sourced from a government-validated database.Claim as a partner

Study start date: January 1, 2005

Actual date on which the first participant was enrolled.

Accessible, usable, and effective vaginal microbicides could significantly decrease the spread of HIV. Vaginal microbicides could be used with condoms to prevent HIV infection; they could also be used in situations in which an individual is unable to negotiate condom use. Vaginal microbicides are potentially bidirectional, preventing both male-to-female and female-to-male HIV transmission. This study will evaluate the safety and effectiveness of two vaginal microbicides, BufferGel and PRO 2000/5, in preventing the transmission of HIV. The study will also evaluate the effectiveness of these gels in preventing other common sexually transmitted infections (STIs). BufferGel is a buffering agent designed to maintain normal vaginal acidity in the presence of ejaculate. Studies have shown that HIV is inactivated below a pH of 4 to 5.8. Carbopol 974, the major nonaqueous component of BufferGel, is commonly used as a gelling or tableting agent and has a well-documented safety record. BufferGel has proven safe and well tolerated in Phase I studies. PRO 2000/5 inhibits viral entry into susceptible cells. PRO 2000/5 has also been evaluated in Phase I studies and was found to be safe and well tolerated. Participants in this study will be randomly assigned to receive one of four interventions: BufferGel, PRO 2000/5, placebo gel, or no gel. All participants will receive HIV risk reduction counseling, condoms, and diagnosis and treatment of sexually transmitted diseases. Participants in the three gel arms will be given single-use, prefilled applicators of gel and will be instructed to apply one dose of the product (BufferGel, PRO 2000/5, or placebo gel) intravaginally up to 60 minutes before each vaginal intercourse while in the study. Participants will be enrolled for approximately 12 to 30 months, depending on when they enter the study. Participants will have two screening study visits and then monthly visits. Monthly study visits may take place at a clinic, the participant's home, or other community site. Monthly visits will include a medical interview; urine testing, including pregnancy testing; HIV and sexually transmitted infection risk reduction counseling; and distribution of study supplies (condoms and gel-filled applicators). Blood collection will occur at selected monthly visits. Four times a year, participants will be seen in the clinic for a more structured medical interview, pelvic exam, and HIV testing. At one of these visits, participants at particular sites who are willing will be asked to complete a behavioral risk assessment. At some visits vaginal fluid swabs will occur. Participants at non-US study sites will be asked for permission for these swabs to be stored for further testing. Assessment interviews will be both face to face and self-reporting.

Official TitlePhase II/IIb Safety and Effectiveness Study of the Vaginal Microbicides BufferGel and 0.5% PRO 2000/5 Gel (P) for the Prevention of HIV Infection in Women 
Principal SponsorNational Institute of Allergy and Infectious Diseases (NIAID)
Last updated: January 18, 2026
Sourced from a government-validated database.Claim as a partner

Protocol

This section provides details of the study plan, including how the study is designed and what the study is measuring.
Design Details

3101 patients to be enrolled

Total number of participants that the clinical trial aims to recruit.

Prevention Study

Prevention studies aim to stop a disease from developing. They often involve people at risk and test things like vaccines, lifestyle changes, or preventive medications.



Eligibility

Researchers look for people who fit a certain description, called eligibility criteria: person's general health condition or prior treatments.
Conditions
Criteria

Female

Biological sex of participants that are eligible to enroll.

Over 18 Years

Range of ages for which participants are eligible to join.

Healthy volunteers allowed

If individuals who are healthy and do not have the condition being studied can participate.

Conditions

Pathology

Blood-Borne InfectionsUrogenital DiseasesGenital DiseasesAcquired Immunodeficiency SyndromeCommunicable DiseasesImmunologic Deficiency SyndromesImmune System DiseasesInfectionsPathologic ProcessesRetroviridae InfectionsRNA Virus InfectionsSexually Transmitted DiseasesSlow Virus DiseasesVirus DiseasesSexually Transmitted Diseases, ViralHIV InfectionsLentivirus InfectionsDisease Attributes

Criteria

Note: Per the 12/15/06 amendment, all study participants will now enter the Phase IIb study. Inclusion Criteria: * HIV uninfected * Have had sexual intercourse at least once in the 3 months prior to study entry * Able to provide adequate contact information to study officials for purposes of follow-up Exclusion Criteria: * History of adverse reaction to latex * Nonmedical injection drug use in the 12 months prior to study entry * Vaginal intercourse more than an average of two times per day in the 2 weeks prior to study entry * Plan to become pregnant in the 30 months after study entry * Plan to travel away from the study site for more than 3 consecutive months in the 30 months after study entry * Plan to relocate away from the study site in the 30 months after study entry * Participation in another clinical trial of a vaginal product * Pregnant within 42 days of study entry * Have a sexually transmitted disease or other reproductive tract infection diagnosed by study staff * Abnormal pelvic exam indicating deep epithelial disruption * Condition that, in the opinion of the investigator, may interfere with the study * Liver or kidney function abnormality of Grade 3 or higher * Blood or blood clotting abnormality of Grade 4 or higher

Study Plan

Find out more about all the medication administered in this study, their detailed description and what they involve.
Treatment Groups
Study Objectives

3 intervention groups are designated in this study

33.333% chance of being blinded to the placebo group

Treatment Groups

Group I

Experimental
BufferGel

Group II

Experimental
Pro 2000/5 Gel (P)

Group III

Placebo
Placeo Gel

Study Objectives

Primary Objectives

Secondary Objectives

Study Centers

These are the hospitals, clinics, or research facilities where the trial is being conducted. You can find the location closest to you and its status.

This study has 8 locations

Suspended

3535 Market Street CRS

Philadelphia, United StatesSee the location
Suspended

University of North Carolina Lilongwe CRS

Lilongwe, Malawi
Suspended

College of Med. JHU CRS

Blantyre, Malawi
Suspended

Chatsworth CRS

Chatsworth, South Africa
Completed8 Study Centers