July 19, 2010

Dear Advocates,

Today, positive results were announced from the CAPRISA 004 Phase IIb microbicide trial of 1% tenofovir gel, which was tested in 889 South African women. Overall, there were 39 percent fewer infections among women who received 1% tenfovir gel compared to women who received the placebo gel. This update provides critical context for advocates seeking to understand the implications of this milestone in biomedical HIV prevention research.  

Download resources, including AVAC and trial sponsors and collaborators' press releases and AVAC's document released in advance of the results: A Cascade of Hope and Questions: Anticipating results of ARV-based HIV prevention trials at www.avac.org/CAPRISA004.

The result from CAPRISA 004 is the first evidence that an ARV-based prevention strategy can reduce risk of HIV infection among HIV-negative people. This trial asked whether a topical gel, applied vaginally within 12 hours before and after sex, reduced women's risk of acquiring HIV via vaginal sex. All of the women in the trial received a standard prevention package including condoms, STI treatment and counseling; all were tested for HIV on a monthly basis. Neither the participants nor the trial team knew who received 1% tenofovir gel or the placebo (the two gels were indistinguishable.)

As the trial team reported, at the end of the 30-month study, there were 39 percent fewer infections among women who received 1% tenofovir gel versus those who received the placebo, with a confidence interval ranging from 6 to 60 (for more on understanding the statistics included in trial result announcements, visit www.avac.org/statsguide).

These findings represent compelling evidence supporting development of 1% tenofovir gel as a new biomedical HIV prevention strategy. Additional follow-up research is needed to learn more about the result. Key questions include the effectiveness of different dosing regimens, safety and effectiveness in adolescents and pregnant women and for rectal use, and additional confirmatory research on the original finding.

While CAPRISA 004 tested a before-and-after sex dosing regimen for 1% tenofovir gel, the ongoing VOICE trial is evaluating the safety and effectiveness of daily use of the same gel. (VOICE is also evaluating safety and effectiveness of tenofovir (Viread) and tenofovir/emtricitabine (Truvada) for oral ARV-based prevention, known as prep-exposure prophylaxis or PrEP.)

AVAC will be releasing an updated version of A Cascade of Hope and Questions later this week. As the document describes, some of the key messages for advocates include:

• The finding from CAPRISA 004 marks an historic moment in biomedical prevention research, and in the search for women-controlled methods--however, it does not provide all of the information needed to support large-scale introduction of the product.
• There is an urgent need to implement parallel agendas that follow up on and confirm the original finding, and, at the same time, map and address manufacturing and regulatory issues in preparation for potential introduction.
• The South African women participants, along with the trial team, are owed a tremendous debt of gratitude for their dedication to biomedical HIV prevention research, as do the participants and implementers of the VOICE trial that will provide additional data. It is critical to articulate and support a specific, South African agenda for following up on CAPRISA 004.

As always, we welcome your questions, thoughts and suggestions and will supply additional materials in the coming weeks and months.

Best,
AVAC