Study of Microbicide Gel Shows Reduced Risk of HIV & Herpes Infections in Women
Tuesday, July 20, 2010
“This is a historic day for HIV prevention
research. The CAPRISA 004 results are the first
clinical evidence that a microbicide gel can
help to prevent sexual transmission of HIV
infection,” said AVAC Executive Director
Mitchell Warren, reacting to the results of the
landmark microbicide trial presented today at
the International AIDS Conference in
Vienna.
“We believe that the most
responsible plan of action now is to quickly
and efficiently articulate the sequence of
steps necessary for confirmation and follow-up
of these results, while also aggressively
planning for potential roll-out of a licensable
product.”
“It will take time and
resources to fully analyze and understand the
data, but this proof of concept demands
immediate action both in South Africa where
there are a range of key, context-specific
issues—and on a global level where this new
evidence will energize and redirect the
microbicide field as well as the broader arena
of prevention strategies based on anti-HIV
drugs. Simultaneous efforts on many fronts are
needed to eventually realize the public health
potential suggested by these
data.”
“We congratulate the trial
sponsors, scientific collaborators, and
partners who conducted this trial, and
especially want to thank the nearly 900 South
African women whose altruism and commitment as
trial volunteers made this effort possible.
These volunteers and their communities have
made an inestimable contribution to HIV
prevention research and to the eventual
development of new ways for women and men all
over the world to protect themselves from HIV.
We owe them an enormous debt of gratitude,”
Warren said.
“As we move forward in
our search for microbicides and other new HIV
prevention options, researchers will need the
collaboration of tens of thousands more men and
women around the world in additional trials.
Right now, the VOICE trial is working in four
countries, including South Africa, to evaluate
both 1% tenofovir gel and oral pre-exposure
prophylaxis—this study is more important than
ever, as are additional trials that have yet to
be planned.”
As the trial team
reported in Vienna today, CAPRISA 004 provided
the first evidence that the use of the
antiretroviral (ARV) drug tenofovir in the form
of a vaginal gel can reduce the risk of HIV
infection in women. The overall rate of
effectiveness reported in the trial was 39
percent. The “test of concept” trial tested
the effectiveness of 1% tenofovir gel, used
before and after sex, among urban and rural
South African women at high risk of HIV via
vaginal sex.
“These results move us
one step closer to finding much needed new HIV
prevention options for women and men,” said
Warren. “We look forward to working with the
field to further examine the great wealth of
data this trial has produced. These data will
help guide decisions about further studies
needed as well as provide important information
to help design implementation programs if
additional research indicates that we have a
licensable product.”
AVAC calls on the
trial sponsors, researchers, funders and others
in the field to work quickly, and cooperatively
to boldly to translate these findings into
development of a scientific action plan to
attempt to confirm these results and answer
other outstanding questions. Such a plan must
be well resourced and swiftly implemented, and
it must ensure that additional supplies of
tenofovir gel can be quickly manufactured to
meet the needs of follow-up
studies.
“As exciting as this result
is—and as important as it is to follow it up
without delay—the reality is that this
product will not be available for widespread
introduction tomorrow. Its critical to manage
expectations while maintaining urgency. This
challenging but necessary work falls on the
shoulders of all stakeholders involved in AIDS
prevention and treatment. At the same time, we
must ensure that all stakeholders reaffirm
their commitments to work that will lead to
eventual access to effective microbicides for
everyone who needs them,” Warren
said.
Additional relevant information
will also come from the ongoing research on
other, related antiretroviral-based prevention
strategies in HIV negative people. These
include trials of pre- exposure prophylaxis, or
PrEP, which is evaluating the use of oral ARVs
to reduce HIV risk in HIV negative people.
There is also one other ongoing effectiveness
trial known as MTN 003, or VOICE, that is
evaluating daily use of 1% tenofovir gel (a
different dosing strategy from CAPRISA 004)
along with oral use of tenofovir or
tenofovir/emtricitabine. The positive finding
from CAPRISA 004 increases hope that there will
be benefit in some of these other trials—but
it is no guarantee. Ongoing and additional
research is needed to clarify the full
potential of ARV-based
prevention.
“This is an astonishing
scientific achievement and a great boost to the
microbicide field. At the same time, the
results are complicated, and we will need to
work hard to make sure that women and their
partners understand what these results do and
do not mean for the immediate future and in the
long-term,” said Warren. “We are committed
to working with communities to understand the
results and the next steps.”
“The
CAPRISA 004 results add immensely to the drive
for a comprehensive response to HIV,” Warren
added. “That means ensuring access for all
who need it to existing HIV prevention and
treatment options, including male and female
condoms, behavior change counseling, male
circumcision, clean needles, harm reduction and
antiretroviral drugs; ensuring continued
research to find effective new options,
including microbicides, PrEP and vaccines; and
planning for integrating these new
interventions into combination
programs.”
CAPRISA 004 was led by the
Centre for the AIDS Programme of Research in
South Africa (CAPRISA) at the University of
KwaZulu-Natal and FHI and CONRAD in the US, and
sponsored by the US Agency for International
Development (USAID) and TIA, a biotechnology
agency of the South African government’s
Department of Science and Technology.
An
AVAC report, A Cascade of Hope and Questions:
Anticipating the results of upcoming ARV-based
prevention trials and additional information
about CAPRISA 004 and other upcoming results
are available online at www.avac.org/caprisa004.