||joya banerjee [ profile ]
Nov 23rd, 2010 - 09:55:20
Understanding iPrEx 23Nov10.pdf
PrEP proves efficacious.... interesting read. I would be more
interested if treatment access were universal, but this is promising
for the future.
Joya Banerjee, MS
Global Health Fellow- Gender Specialist
U.S. Centers for Disease Control and Prevention, South Africa
Tel: +27 (0)12 424 9000
Mobile: +27 (0)7 65 49 0885
Email: BanerjeeJ (at) sa.cdc.gov
Dear MTN Family and Friends:
We are writing to share some exciting news about the results of the
iPrEx study, which have just been published online in the New England
Journal of Medicine.
iPrEx has provided the first evidence that oral pre-exposure
prophylaxis, or PrEP, can indeed help prevent HIV. The iPrEx study
found that daily use of Truvada together with a comprehensive HIV
prevention package resulted in a nearly 44 percent reduction in HIV
risk compared to placebo among men who have sex with men. Coming on
the heels of CAPRISA 004, which provided proof of concept for
tenofovir gel, we are definitely on a roll!
It is a time to celebrate and recognize the iPrEx study team for the
enormity of its contribution to HIV prevention research. It is also a
time to be humbled by the work that it leaves in our hands. As a
field, it is imperative that we build on this success on behalf of all
at-risk populations. As the MTN, it is our responsibility to work
toward realizing the full potential of oral and topical PrEP in women.
iPrEx (Pre-Exposure Prophylaxis Initiative) was a double-blind,
randomized controlled Phase III trial that enrolled 2,499 sexually
active HIV-negative men who have sex with men at 11 sites in six
countries: Peru (Lima and Iquitos), Ecuador (Guayaquil), Brazil (Rio
de Janeiro and Sao Paulo); the United States (Boston and San
Francisco), South Africa (Cape Town) and Thailand (Chiang Mai). The
trial started in June 2007 and enrollment was completed in December
2009. Study drug was stopped in all participants in August 2010.
Post-drug stop visits have been taking place since September. While
follow-up of participants in sub-studies continues, the primary
analysis of results includes participants who were followed until May
1, 2010 an average of 14 months.
As stated above, Truvada was associated with a 44 (43.8) percent HIV
risk reduction. This finding was statistically significant (P =
0.005), with a confidence interval of 15 to 63 percent. Importantly,
there were no significant safety concerns. Showing that consistent use
of Truvada is associated with higher levels of protection is perhaps
the most compelling of the results. Among those who took the drug more
than 90 percent of the time, there were nearly 73 percent fewer HIV
infections, according to pill and bottle counts and self-reports. In a
subset of participants in the Truvada group, blood tests measuring
levels of activated drug indicated that only half had taken the study
drug as directed. However, in those participants whose blood levels
suggested that they were compliant with pill taking, HIV risk was
reduced by more than 90 percent compared to those who were not.
We often talk about being at a crossroads, but that is quite literally
where VOICE is, as the only trial testing both tenofovir gel and oral
PrEP. VOICE will tell us about the safety and efficacy of daily use of
tenofovir gel, information that will serve to complement the CAPRISA
004 results and possibly lead to product licensure. The oral arms of
VOICE will tell us about safety and efficacy of daily use of the ARVs
tenofovir and Truvada in women. Nearly 2,500 women are enrolled in
VOICE were halfway toward our goal.
The next few years will be critically important, with results expected
from the CDC Bangkok Tenofovir Study, FEM-PrEP and the Partners PrEP
Study, not to mention VOICE. In addition, we await the start of the
International Partnership for Microbicides (IPM) Phase III Dapivirine
ring study. The MTN portfolio of rectal safety, pregnancy and PK
studies will provide essential pieces to the puzzle. And we will look
forward to studies of new formulations with our partners at the
Population Council and IPM.
We would not be looking to the future with the same measure of
anticipation and optimism if not for the preceding accomplishments.
This has been an exciting and memorable year for HIV prevention. Soon,
we will be entering a new decade. Let it be the one that will be
remembered for halting the spread of HIV.
Please join us in recognizing both Bob Grant, of the Gladstone
Institute of Virology and Immunology, and study co-chair Javier R.
Lama of Investigaciones Medicas en Salud, a Peruvian-based research
organization, whose combined scientific vision and leadership
contributed to the studys success; their extraordinary colleagues at
their respective institutions and the entire roster of international
investigators. Incidentally, this includes Ken Mayer, MTN-007 protocol
co-chair, and others from the Fenway Community Health CTU. We would
also like to acknowledge our colleagues at DAIDS, the Bill & Melinda
Gates Foundation and Gilead Sciences.
On behalf of the entire MTN family, we want to thank and congratulate
everyone, most importantly the study participants, for their important
contribution and for giving us hope.
MTNs statement and fact sheet are attached but also available at
www.mtnstopshiv.org Links to the NEJM paper and additional materials
about these exciting results are provided below.
New England Journal of Medicine article:
iPrEx Study press release and fact sheets: http://www.iprexnews.com
iPrEx study materials NIAID: