July 13, 2011
Today, researchers from two different studies of oral pre-exposure prophylaxis (PrEP) announced evidence that both oral tenofovir (TDF, marketed as Viread) and oral tenofovir plus emtricitabine (TDF/FTC, marketed as Truvada) can reduce the risk of HIV transmission among men and women whose primary route of HIV exposure is penile-vaginal sex. These landmark findings, which came from the Partners PrEP and CDC TDF2 trials, extend the benefit previously observed in gay men and transgender women in the iPrEx trial and have the potential to fundamentally change approaches to HIV prevention.
On Thursday, July 14 at 7 am EDT / 1 pm South Africa / 2 pm East Africa, AVAC will host a global teleconference with trial investigators to discuss these findings. Click here to register. To confirm the time in your area, please visit www.timeanddate.com. This will be one of several opportunities to discuss these results, and even if you can’t make Thursday’s call, we encourage you to send your questions to firstname.lastname@example.org. The call will be recorded and made available on our website.
AVAC will be preparing a document designed to help advocates understand and analyze these findings in-depth. Some brief, key facts from the findings to date:
Click here for AVAC’s PrEP resource page, which contains press releases, FAQs and other documents on both TDF2 and Partners PrEP. More detail is also provided below.
Today’s findings make even more critical that stakeholders act on recommendations put forward in the statement, “We CAN End the AIDS Epidemic”, which has been endorsed by more than 30 organizations and close to 400 individuals around the world to date. In our press release on the new data, we highlight the need for these next steps:
The Partners PrEP trial enrolled 4,758 couples in which one partner was HIV-positive and the other was HIV-negative (a serodiscordant couple). Partners PrEP was scheduled to run (with its placebo arm) until 2013. At a meeting on July 10, the trial’s Data and Safety Monitoring Board (DSMB) recommended that the trial discontinue its placebo arm and announce its results to the public due to overwhelming evidence of benefit. Through May 31, 2011, a total of 78 HIV infections occurred in the trial: 18 among those assigned to the TDF study arm, 13 among those assigned to the TDF/FTC arm and 47 among those assigned placebo. Thus, those who received TDF had an average of 62 percent fewer HIV infections (95% CI 34 to 78, p=0.0003) and those who received TDF/FTC had 73 percent fewer HIV infections (95% CI 49 to 85, p<0.0001) than those who received placebo.
TDF2 was an expanded safety study of TDF/FTC in just over 1,200 sexually active men and women at two sites in Botswana. At the time of its completion, TDF2 was not designed to answer questions about the effectiveness of PrEP using TDF/FTC. However, there were statistically significant differences observed in risk of HIV among both men and women who received TDF/FTC along with a comprehensive prevention package compared with those who received the placebo plus the same prevention package.
At the end of the study, there were 33 total infections, nine in the TDF/FTC arm and 24 in the placebo arm. This translates to a 62.6 percent reduction in HIV risk (95% CI 21.5 to 83.4, p=0.0133) in an intent-to-treat analysis (this includes all trial participants, regardless of the time spent in the study or reported adherence to the study regimen).
It will be critical for advocates to discuss the meaning of these findings for various contexts. Additional data not released today, but expected in the coming months, will also add to the picture. These include data on drug resistance from Partners PrEP, data on drug levels in blood plasma, cells and tissue samples, and viral genotyping of infecting strains within Partners PrEP couples to identify linked and unlinked transmissions, and other information.
AVAC will work with its civil society and research partners around the world to develop questions, answers where possible, priorities and a shared advocacy agenda to help ensure that today’s results lead to action to help end the epidemic.
As always, we want to hear from you! Send questions and comments to email@example.com and look out for our coverage of discussions of PrEP and ARV-based prevention from the International AIDS Society Conference, July 17-20 in Rome. You can follow AVAC at the conference on Twitter and Facebook.