HIV prevention study does not confirm pericoital tenofovir gel effectiveness: protection observed in small group of women who used the product consistently
Seattle, WA — Results of the FACTS 001 trial, which tested whether a vaginal gel containing 1% tenofovir (TFV) could prevent HIV and herpes (HSV) infections in women when used before and after sex, did not show reduction in HIV infections in the group of participants assigned to TFV gel. The gel was only effective when used consistently and covered most of the sex acts, but most women in this trial were unable to use it in this manner. Analysis of HSV-2 data is ongoing and not available at this time.
Overall, out of 2059 enrolled participants, a total of 123 HIV infections occurred, with 61 in the TFV arm and 62 in the placebo group. Both groups had an average of 4% incidence rate of infection (i.e., four out of 100 women acquired HIV per year). Participants used the gel during an average of 50-60% of sex acts per month, based on returned applicators and self-reported number of sex acts, with 13% of the participants using gel during greater than 80% of sex acts. A cohort analysis of 214 participants in the TFV-treated group showed that detection of TFV in genital fluids was significantly associated with a 52% reduction in HIV acquisition. In the same analysis, women who did not use the gel at all (no drug detected in genital samples) were more likely to become infected.
While the gel showed a protective effect in women who used it consistently as prescribed by the study protocol, high adherence in the overall study population was too low to show TFV gel effectiveness in this trial.
These study results were presented today at the annual Conference on Retroviruses and Opportunistic Infections (CROI) in Seattle, Washington. The FACTS 001 trial was designed as a confirmatory study for a smaller, earlier trial of TFV 1% gel called CAPRISA 004, which showed an overall 39% reduction in HIV infections and 51% reduction in HSV-2 infections.
“The FACTS 001 trial did not show TFV gel effectiveness when the entire population of trial participants was analyzed. A protective effect, however, was seen in women who used the product consistently in all or most of their sex acts throughout the study. While the gel appeared to be acceptable and easy to apply, for most of this population of young, unmarried women, the majority of whom still live with their parents, using the gel consistently proved to be very challenging,” said Dr. Gustavo Doncel, Scientific and Executive Director of CONRAD. “More end-user centered research is needed to understand barriers and motivators of product use, as well as preferred methods and dosage forms.”
“Methods that are easier to use, are long-acting such as vaginal rings and injectables, or add another benefit such as contraception along with HIV prevention, also called multipurpose prevention technologies (MPTs), may offer an additional motivation for adherence,” added Dr. Jill Schwartz, CONRAD Medical Director.
The nine-site South African study was led by the Wits Reproductive Health and HIV Institute in Johannesburg and was sponsored by CONRAD. A total of 2059 women from 18 to 30 years of age who were already at high risk of HIV infection participated in the 2 ½ year study which took place in urban, peri-urban and rural sites throughout the country. The average age of the participants was 23 years; 89% were unmarried and more than 60% lived with parents or other family members. About 42% of the participants were HSV-2 positive at enrollment.
Upon enrollment, the women were randomized into two groups, with half of the women assigned to TFV gel and the other half assigned to a placebo gel – neither the participants nor the study staff knew which gel they were assigned. Women were required to insert the gel before and after intercourse, not to exceed two doses in 24 hours.
Dr. Schwartz stated, “The FACTS 001 study team has done an excellent job in conducting this large multicenter trial, having implemented a client-centered approach based on motivational interviewing and creative retention strategies to encourage participants to attend their regular visits and use the products.”
The FACTS 001 study participants were provided with condoms and pre-filled gel applicators during monthly clinic visits, and were tested for HIV and other sexually transmitted infections. Adherence was measured by determining how many sex acts were covered with gel use based on returned empty gel applicators and self-reporting of sex acts. Genital fluids were collected quarterly in order to measure drug levels. Participants were counseled and encouraged to protect themselves from HIV. Women who acquired HIV during the trial, or who were found to be HIV positive during the initial screening, were referred to local clinics for care.
FACTS 001 was funded by the South African Department of Science and Technology, the U.S. President's Emergency Plan for AIDS Relief (PEPFAR) through the U.S. Agency for International Development (USAID), The Bill & Melinda Gates Foundation and the South African Department of Health, with products provided by CONRAD and support from Gilead Sciences.
“USAID and PEPFAR remain dedicated to supporting HIV prevention products that serve vulnerable women throughout the world” said David Stanton, Director of USAID’s Office of HIV/AIDS. “These new prevention technologies, such as long-lasting injectables, vaginal rings, or topical treatments, may surmount the adherence barrier seen in the FACTS 001 trial and ultimately contribute to an AIDS-free generation.”
Other studies using TFV gel for HIV prevention are ongoing or have just been completed, including CAPRISA 008, which is an open-label trial assessing the implementation of TFV gel provision through family planning services in KwaZulu-Natal, South Africa, which will be complete in 2015. MTN 017, sponsored by the Microbicide Trials Network and funded by the US National Institute of Allergy and Infectious Diseases, is testing the safety of a reduced glycerin formulation of TFV gel which is applied rectally in men who have sex with men and in transgender women. Additionally, HSV-2 data from FACTS 001, CAPRISA 004 and VOICE will be analyzed to further evaluate TFV gel’s potential for genital herpes prevention.
“CONRAD will continue working to develop safe and effective HIV prevention products, whether in gel form or other less user-dependent delivery systems designed to increase acceptability and adherence. Young women in Africa continue to be at high risk of acquiring sexually transmitted infections, especially HIV and herpes, and urgently need different prevention methods they can more easily incorporate into their lifestyles and use consistently,” said Dr. Doncel.
CONRAD (www.conrad.org) was established in 1986 and is a Division of the Department of Obstetrics and Gynecology at Eastern Virginia Medical School (EVMS) in Norfolk, VA, where its laboratories and clinical research center are located. With funding from the U.S. President's Emergency Plan for AIDS Relief (PEPFAR) through the U.S. Agency for International Development (USAID), the Bill and Melinda Gates Foundation, and the National Institutes of Health, among others, CONRAD is a leader in researching and developing new contraceptive options and products to prevent HIV and STIs. CONRAD collaborates with academic and research institutions around the world. The main office is located in Arlington, VA.