July 13, 2011
San Francisco, CA, USA -- The iPrEx Open-Label Extension Study (iPrEx OLE), the next phase of the first human study to report efficacy results on pre-exposure prophylaxis (PrEP) to prevent HIV infection, has begun at clinical trial sites around the world. Approximately 2,000 men and transgender women who have sex with men are expected to participate in the 72-week iPrEx OLE study (www.iprexole.com). Study sites in the United States and South Africa are enrolling participants now, as other study sites finalize the regulatory approval process.
In PrEP, antiretroviral medications that are usually used to treat HIV are taken by uninfected people to reduce their risk of infection. The iPrEx study found that men and transgender women who have sex with men (MSM) who took a single daily tablet containing the HIV medications emtricitabine and tenofovir (FTC/TDF), known commercially as Truvada®, experienced an average of 44% fewer HIV infections than those who received a placebo (blank pill). HIV infection rates in the iPrEx study dropped by 90% among those who used PrEP consistently enough to have detectable drug in the body. The HIV risk reduction benefits of PrEP were in addition to those provided by safer sex counseling, condoms, HIV testing and the detection and treatment of sexually transmitted infections. iPrEx study results were published in the New England Journal of Medicine in November, 2010 (www.nejm.org/doi/full/10.1056/NEJMoa1011205).
The news of the start of iPrEx OLE follows the announcements by two other major PrEP studies, Partners PrEP and the CDC study in Botswana, known as TDF2, which demonstrated the safety and efficacy of PrEP in heterosexual women and men.
iPrEx OLE is a continuation of the iPrEx study that will collect additional data on PrEP efficacy, safety and adherence. All HIV-negative participants who took part in the original iPrEx study and who wish to participate will receive FTC/TDF for HIV prevention for 72 weeks through iPrEx OLE. No placebo will be used in the Open Label Extension.
"We are in a critical moment in HIV prevention research," said iPrEx Protocol Chair Robert Grant, MD, MPH of the Gladstone Institutes and the University of California at San Francisco. "iPrEx provided the first proof of an important new method of HIV prevention that can help slow the global toll of 2.6 million new HIV infections each year. Partners PrEP and the TDF2 study have now expanded that finding by demonstrating the effectiveness of PrEP in heterosexual women and men. Developing and deploying proven HIV prevention methods -- including PrEP, microbicides, vaginal gels, clean needles, medical male circumcision, early treatment, counseling, testing, condoms and suppressive therapy for pregnant women will all be key to slowing the global epidemic."
In addition to collecting longer-term data on PrEP efficacy and safety, iPrEx OLE will provide important additional information about whether study participants are able to use PrEP more consistently now that its HIV prevention benefit has been demonstrated and participants know they are receiving active drug. As with the original iPrEx study, iPrEx OLE participants will receive a comprehensive package of HIV prevention tools in addition to PrEP, including HIV testing, condoms, counseling, and diagnosis and treatment of sexually transmitted infections. Some iPrEx OLE trial sites started enrolling participants in June, and all sites are expected to be fully operational by August 2011. One additional study site, in Chicago, USA, will be added to the sites that participated in the original iPrEx study. The iPrEx OLE study sites are:
"iPrEx OLE continues our tradition of forward-looking HIV research conducted in close consultation with communities affected by HIV," said iPrEx OLE Principal Investigator Orlando Montoya of the Fundación Ecuatoriana Equidad in Guayaquil, Ecuador. "As with the original iPrEx study, iPrEx OLE was developed with the participation of potential volunteers, community leaders, stakeholders, governments, sponsors, local Community Advisory Boards, activists and members of at-risk communities. We are proud to continue to participate in this important and truly community-based HIV prevention study."
iPrEx OLE is one of several clinical trials of PrEP currently underway in different communities at risk, including heterosexual couples and injecting drug users. More information about PrEP and current PrEP research is available from AVAC: Global Advocacy for HIV Prevention at www.avac.org/ht/a/GetDocumentAction/i/3302.
The iPrEx study (Iniciativa Profilaxis Pre Exposicion or Prexposure Prophylaxis Initiative) (www.iprexole.com), was a double-blind, placebo controlled Phase III clinical trial that began in 2007 following three years of community consultation. iPrEx was the first human efficacy study of PrEP to report efficacy data. Detailed information about the results of the iPrEx study is available at www.iprexnews.com/studyresults/english.html. iPrEx was sponsored by the U.S. National Institutes of Health (NIH) through a grant to the Gladstone Institutes, a non-profit independent research organization affiliated with the University of California at San Francisco. Additional support for the study was provided by the Bill & Melinda Gates Foundation.
iPrEx OLE (Open Label Extension) is a continuation of the iPrEx study designed to provide extended safety and efficacy information on PrEP and additional data on the behavior of people taking PrEP over a longer term. The study is sponsored by the Division of AIDS (DAIDS) of the National Institutes of Health (NIH) through a grant to the Gladstone Institutes in San Francisco California. Gilead Sciences donates drug for iPrEx OLE but does not participate in the design, conduct or analysis of the study.
What is iPrEx OLE?
iPrEx OLE (OLE stands for "Open Label Extension") is a continuation of the iPrEx study designed to provide additional information about the safety of PrEP and the behavior of people taking PrEP over a longer term.
Where will iPrEx OLE take place?
iPrEx OLE will take place at 11 sites in Peru, Ecuador, Brazil, the United States, South Africa and Thailand. One additional site, the CORE Center Chicago, in Chicago, Illinois (USA) will be added to the previous iPrEx study sites for the Open-Label Extension phase of the study.
When will iPrEx OLE begin, and how long will it last?
iPrEx OLE is expected to be fully enrolled by late 2011 and every participant will be followed for 72 weeks. Participants will visit the study clinics at four, eight and 12 weeks, and every 12 weeks thereafter.
What are the aims of iPrEx OLE?
iPrEx OLE will gather additional information about the use of Truvada PrEP, including information on the long-term safety and efficacy of PrEP with FTC/TDF, pill taking and adherence, any changes in participants' sexual behavior, drug resistance and any possible side effects including effects on bone mineral density and fat distribution.
What HIV prevention services will iPrEx OLE participants receive?
As with the original iPrEx study, iPrEx OLE participants will receive a comprehensive package of HIV prevention tools in addition to PrEP, including HIV testing, condoms, counseling and diagnosis and treatment of sexually transmitted infections.
Who sponsors iPrEx OLE?
The study is sponsored by the Division of AIDS (DAIDS) of the U.S. National Institutes of Health (NIH) through a grant to the Gladstone Institutes in San Francisco California. Gilead Sciences donates drug for iPrEx OLE, but does not contribute financially to the study and does not participate in its design, conduct or data analysis.
Where can I get more information about iPrEx OLE?
For more information on the original iPrEx study and iPrEx OLE, please visit www.iprexole.com.