MDP Statement on the discontinuation of tenofovir tablets in the VOICE trial
29th September 2011
The Microbicide Trials Network (MTN) and the US National Institutes of Health
(NIH) today announced their decision to discontinue the oral tenofovir tablets
arm, in VOICE, a major HIV prevention trial being conducted among women in
South Africa, Uganda and Zimbabwe.
This decision follows a recommendation by the independent Data and Safety
Monitoring Board after their routine review on the 16th September 2011 revealed
that there was no possibility of demonstrating benefit from tenofovir tablets.
More details are available on the MTN website http://www.mtnstopshiv.org/
The participants that have been allocated Truvada tablets and tenofovir vaginal
gel, and both placebo groups, will continue to receive product. Women that were
allocated tenofovir tablets will stop product, and exit the study in an orderly
The final results will not be known until early 2013. They will provide important
insight into the factors that underlie the effectiveness (or otherwise) of antiretrovirals
in reducing HIV.
The MDP investigators are familiar with the challenges of discontinuing one
product in an ongoing placebo-controlled trial. We sympathise with the VOICE
investigators and wish them all the best for their important work in the
remaining months of the trial.
Clinical trials, such as VOICE, are necessary because we need to rigorously
evaluate the benefits of new interventions. While this interim result is
disappointing, it is highly relevant to our understanding of HIV prevention.
MDP Statement on FEM-PrEP trial closure
18 April 2011
FHI today announced their decision not to complete the FEM-PrEP trial as planned in the protocol, following a scheduled interim review.
The Independent Data Monitoring Committee reviewed the available data which included 56 seroconversions. The committee concluded that the likelihood of showing protection against HIV was so remote, there was little point in continuing the trial until 72 HIV seroconversions had been observed, as planned. Consequently, FHI decided to proceed with an orderly closure of the study.
The study team plan to conduct at least three final follow-up visits for each participant over the next 3 to 4 months. They will complete further analyses to try and understand why there did not appear to be evidence of protection in this study population.
Truvada did not increase nor decrease the risk of HIV acquisition. It is particularly unexpected that oral Truvada did not show protection for women in light of the preceding trials that showed benefit to women with a vaginal application of tenofovir (CAPRISA 004), and to men who have sex with men with oral Truvada (iPrEx).
While the results are disappointing, they are of critical importance to HIV prevention. The very reason for conducting a clinical trial is because we are uncertain of the effect of a new product and this result highlights the importance of conducting multiple clinical trials in different population groups. The past, and ongoing, contributions of the women and communities in Kenya, South Africa and Tanzania that have engaged in FEM-PrEP, and the efforts of the study team, will advance the field and are accordingly of great value.
There are three ongoing trials assessing oral tenofovir based regimens for the prevention of HIV, in diverse populations, and these will provide further evidence in due course to help us understand the appropriate role of oral pre-exposure prophylaxis.
The FHI statement is available at: http://www.fhi.org/en/Research/Projects/FEM-PrEP.htm
iPrEx provides further evidence that the use of antiretrovirals prior to exposure can safely reduce the risk of HIV acquisition
29 November 2010
The MDP partners congratulate the iPrEx team
and study participants for successfully completing a Phase III clinical
trial designed to determine whether daily Truvada®
(tenofovir/emtricitabine combination) can safely prevent HIV infection
among men and transgender women who have sex with men (MSM).
The iPrEx study enrolled 2,499 MSM at higher risk of HIV infection in
11 centres in 6 countries. This was the first large scale clinical
trial of Pre-Exposure Prophylaxis (PrEP) conducted amongst MSM.
Participants allocated to daily Truvada® had 44% fewer infections
compared to those allocated to placebo. The protection demonstrated
adds to the evidence that anti-retrovirals used prior to exposure
reduce the risk of HIV acquisition.
The iPrEx result follows on the success of the vaginal microbicide gel
reported by the CAPRISA team in which women who received 1% tenofovir
gel (used before and after sex) had a 39% lower risk of HIV infection
compared to women receiving placebo gel.
In both trials the investigators collected self-reports of drug use and
measured drug levels. Although self-reported adherence was high, drug
levels suggest adherence was modest, and this seems to be the most
likely explanation for effectiveness being lower than expected. One way
to improve adherence, and therefore effectiveness, could be to simplify
the regimen and reduce the dosing.
To address this important question for microbicides, MDP partners in
Mozambique, South Africa, Tanzania, Uganda and Zambia are seeking
funding for a study designed to compare adherence to a single dose of
1% tenofovir used prior to sex to the ‘before and after’
dosing known as BAT24, and to assess the relative effectiveness of each
regimen against placebo. This study, which will build on the successful
MDP international collaboration, will also implement a visit schedule
that is achievable for widespread implementation in resource limited
MDP is delighted that the ANRS plans to start a trial evaluating the
intermittent use of PrEp among MSM within 6 months. We also look
forward to the results of the VOICE (Vagina and Oral Interventions to
Control the Epidemic) trial which is evaluating daily 1% tenofovir
vaginal gel against placebo, as well as tenofovir and Truvada® as
oral prophylaxis. It will be especially interesting to know the
relative effectiveness of vaginal application compared to oral dosing
in the same study populations in VOICE. Vaginal application of
antiretrovirals has the advantages of higher levels of drug in the
genital tissue, and lower levels in the blood, which is assumed to
reduce the risk of toxicity and emergent resistance in primary
infections, particularly when detecting infection at an early stage
remains a challenge.
The need for HIV prevention options for women and men is even more
urgent as evidence is growing that services are struggling to deliver
treatment. The iPrEx result is a step in the right direction and the
MDP is ready to play its role in the future trials required. With a
majority of the 1.8 million new HIV infections occurring amongst women
in Sub-Saharan Africa in 2009, collecting reliable evidence of the
effectiveness of a single dose of tenofovir vaginal gel applied prior
to sex is an urgent necessity and a priority for the MDP.
CAPRISA provides ground-breaking evidence
the use of an antiretroviral drug (Tenofovir) in the form of a vaginal
gel can prevent HIV infections in women
20 July 2010
London, July 20, 2009. The MDP partners congratulate the trial team and
study participants on successfully completing the CAPRISA 004 trial of
the 1% tenofovir microbicide gel, and are delighted to see proof for
the concept of microbicides.
CAPRISA 004 was a phase IIb trial conducted in South Africa involving
889 HIV negative women. The trial assessed the effectiveness and safety
of a vaginal gel containing the antiretroviral drug tenofovir, for the
prevention of vaginally acquired HIV infection. The trial demonstrated
that after 30 months of gel use, women who used 1% tenofovir gel had 39
percent fewer HIV infections compared to women who used the placebo gel
during sex acts.
This is a major scientific breakthrough for microbicide research, and
for antiretroviral prophylaxis. “Excited – yes!
roll out – not quite” said Dr Sheena McCormack, MDP
Chief Investigator. Drug development is a long process and additional
evidence from further trials in more diverse populations will be
required to confirm the CAPRISA result before tenofovir gel could be
made widely available as a HIV prevention option. “Caprisa
a step in the right direction and MDP is ready to get on that
path!'” added Dr McCormack.
The MDP looks forward to the results of the VOICE (Vagina and Oral
Interventions to Control the Epidemic) trial which is evaluating the
same candidate microbicide used every day, and the trials of oral
antiretroviral prophylaxis such as iPrEx and FemPrep.
There continues to be an urgent need for additional HIV prevention
options for women and men, and this exciting result will provide
momentum to the search for safe, effective and acceptable microbicides.
The MDP is ready to play its part in the future trials required.
For more information on the CAPRISA study visit www.caprisa.org
HIV ‘prevention’ gel
PRO 2000 proven ineffective
The largest international clinical trial to date into a preventative
HIV gel has found no evidence that the vaginal microbicide, PRO 2000,
reduces the risk of HIV infection in women, scientists announced today.
This placebo-controlled trial involved 9,385 women at six research
centres in four African countries and found that the risk of HIV
infection in women who were supplied with PRO 2000 gel was not
significantly different than in women supplied with placebo gel.
Although ineffective in providing protection, PRO 2000 gel itself was
safe to use.
A vaginal microbicide is a product intended for use before sexual
intercourse to help reduce HIV infection, as it is clear that condom
promotion alone has not controlled the epidemic. The gel was given to
participants together with a package of prevention against HIV
infection that included free condoms, counselling for safer sex
negotiation and sexual health throughout the trial.
The trial, known as MDP 301, took place between September 2005 and
September 2009 and was carried out by the Microbicides Development
Programme (MDP), a not-for-profit partnership of 16 African and
European research institutions. It was funded by the UK Department for
International Development (DFID) and the UK Medical Research Council
To date, no microbicide has been shown to be effective against HIV
infection. This trial shows conclusively that PRO 2000 gel is of no
added benefit, ending scientific speculation about its clinical
MDP 301 Chief Investigator, Dr Sheena McCormack of the Medical Research
Council said: "This
result is disheartening; particularly in light of the results of a
smaller trial sponsored by the US National Institutes of Health (NIH)
which suggested that PRO 2000 could reduce the risk of HIV infection by
30 per cent. Nevertheless we know this is an important result and it
shows clearly the need to undertake trials which are large enough to
provide definitive evidence for whether or not a product works."
Professor Jonathan Weber, co-Chair of the MDP Programme Management
Board from the Division of Medicine at Imperial College London, said: "This
is a disappointing result for the product, as the trial shows that it
is not effective. However, the trial itself was very well designed and
undertaken, so we know that the results are definitive.
"It is unfortunate that this microbicide is ineffective at preventing
HIV infection, but it’s still vital for us as scientists to
continue to look for new ways of preventing HIV. There are many
research groups exploring different avenues to tackle HIV; it is a slow
process, but we are making progress. Now that we know this microbicide
is not the answer, we can concentrate on other treatments that might
Dr Maureen Chisembele, Principal Investigator of the Zambian site,
Sub-Saharan Africa, nearly 60 per cent of all people living with
HIV/AIDS are women. Many are highly vulnerable to HIV despite the fact
that they are faithful to their partners. The women will be
disappointed by this result as they really liked the gel and hoped it
A South African trial participant commented: "Even though the
gel proved not to be effective, we played a role in the fight against
HIV. We learnt a lot about caring for ourselves, such as using condoms.
We also learnt to encourage others to test for HIV and we gained
confidence in helping those who were already infected."
The trial participants are being informed of the trial outcome. The
full results will be submitted for presentation at international
conferences in 2010, as well as for publication in a peer-reviewed
The gel used in the study was provided by Endo Pharmaceuticals, a
specialty pharmaceutical company with headquarters in Chadds Ford,
301 General Q&A (PDF)
301 Results Q&A (PDF)
301 Quick Facts (PDF)
301 Technical Fact Sheet (PDF)
For media queries, please contact the MRC press office on 0207 637 6011
information about the MDP 301 microbicides trial can be found at http://www.mdp.mrc.ac.uk/
were 130 HIV
infections out of 3,156 women who were given 0.5% PRO 2000 gel, and 123
HIV infections out of 3,112 given the placebo gel in the main analysis.
The rates of HIV infection were very similar in both groups: 4.5 per
hundred women years in the 0.5% PRO 2000 group, and 4.3 in the placebo
group. Thus 0.5% PRO 2000 gel did not reduce the risk of HIV infection,
and this was confirmed in the statistical analysis. The measure
‘per hundred women years’ takes into account the
periods of time the women participated in the trial as well as the
number of women involved and is used to calculate the risk of becoming
infected by HIV. This is also known as the incidence rate.
were randomly assigned to PRO 2000 gel or a placebo gel group. Women
were asked to use the gel before each sex act and were also given
condoms and counselled to use them together with gel. Women were
followed up for 12 months (or up to 24 months in Uganda) and were
evaluated regularly. All were provided with safe sex counselling,
treatment for sexually transmitted infections and referral for other
non trial-related medical conditions
included a major social science component which has yielded important
new information about sexual behaviour and adherence, as well as
factors which encourage or inhibit condom use. The social science
research was coordinated by the London School of Hygiene and Tropical
Medicine and the Barcelona Centre for International Health Research.
conducted at the following research centres (principal investigators at
each centre are named in parentheses): University Teaching Hospital,
Lusaka, Zambia (Dr Maureen Chisembele); Medical Research Council Uganda
Virus Research Institute, Entebbe (Dr Anatoli Kamali); African Medical
and Research Foundation and National Institute for Medical Research,
Mwanza, Tanzania (Prof Richard Hayes); the Africa Centre for Health and
Population Studies, KwaZulu-Natal, South Africa (Mitzy Gafos); South
African Medical Research Council, Durban, South Africa (Prof Gita
Ramjee); and the Reproductive Health and HIV Research Unit, Department
of Obstetrics and Gynaecology, University of Witwatersrand,
Johannesburg, South Africa (Prof Helen Rees). Contract Laboratory
Services of South Africa (Prof Wendy Stevens) served as a central
reference laboratory for serology testing and confirmation and provided
Good Clinical Laboratory Practice training to nearly 60 laboratory
staff at the research centres. Feasibility studies for future trials
have been carried out in Mozambique, at the Health Research Centre in
Manhiça and at Mavalane Hospital in Maputo (Dr Sibone
trial of this
scale and complexity could not have been completed without the
involvement of many people across Africa, Europe and the US. MDP thanks
all the participants, staff and communities whose enthusiasm and
commitment made this study possible. They also extend their thanks to
their colleagues in the field of microbicides and HIV prevention whose
work contributed to this study.
the trial was provided by the Clinical Trials Unit of the UK Medical
Research Council and Imperial College London. Other European partners
involved in MDP 301 included the London School of Hygiene and Tropical
Medicine; St. George’s Hospital, London; and the Universities
York, Southampton and Barcelona.
MDP 301 trial
leaves a strong legacy. New laboratories have been equipped and
accredited. Research centre staff have gained experience and training
in conducting clinical trials to the highest international standards.
Many were supported to acquire degrees and diplomas which will advance
their careers. Thousands of women have received counselling that will
help them practise safer sex and lead healthier lives. The trial has
helped many women to discuss HIV prevention with their partners.
Medical Research Council
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congratulate CAPRISA trial team (PDF)
‘prevention’ gel PRO 2000 proven ineffective (PDF)
Development Programme announces date of release of the main findings of
the MDP 301 Phase III trial of PRO 2000 vaginal microbicide gel (PDF)
Development Programme update on release of results of the MDP 301 Phase
III trial of PRO 2000 microbicide gel (PDF)
301 Completion of follow up web announcement v1.5 (PDF)
Announcement 10 February 2009 Statement and FAQs (PDF)
Announcement 19 December 2008 Statement (PDF)
Announcement 20 August 2008 Statement (PDF)
Announcement 11 June 2008 Statement (PDF)
Announcement 14th February 2008 Statement (PDF)
Announcement 14th February 2008 Q&A (PDF)