Global microbicides conference reveals more data examining hormonal contraceptive use and HIV risk

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Furthering a hot topic of debate over the last several months wrought with conflicting evidence from various clinical trials, investigators at the 2012 International Microbicides Conference in Sydney presented new data looking at the use of hormonal contraceptives and HIV transmission risk. The new data emerged from the HIV Prevention Trials Network (HPTN) 035 study – a phase IIB safety and efficacy study looking at 0.5 percent PRO 2000 gel and BufferGel as vaginal microbicides, the primary results of which were made available more than three years ago. In this new retrospective analysis looking at nearly 3,000 women enrolled at just one of the seven trial sites, researchers concluded that the use of hormonal contraceptives, oral or injectable, did not place women at a greater risk of acquiring HIV infection. Of note, however, was the statistically significant greater risk of HIV infection when hormonal contraceptive use was coupled with a Chlamydia or gonorrhea diagnosis, according to a press release from the Microbicide Trials Network (MTN).

After some studies suggested an increased risk of HIV acquisition when using progesterone-only injectable contraception, the World Health Organization (WHO) developed a technical statement on the subject and decided to uphold current guidance on the use of hormonal contraceptives because the totality of data is inconclusive. The WHO urged further research on the subject, as well as an expansion of contraceptive method mix. Women choosing to use progesterone-only injectables should be warned of the possible risks, the WHO recommended, and advised to always use condoms and other HIV preventive measures.

“Experts who reviewed the data [at WHO] felt that some of the benefits of hormonal contraception (e.g. fewer maternal deaths, family planning) outweighed the questions raised about increased risk for HIV infection,” said Ken Mayer, MD, of Fenway Health and co-chair of the Center for Global Health Policy’s Scientific Advisory Committee. “The consensus was that further research about how to motivate the use of dual protection (e.g. hormonal modalities or intrauterine devices plus condoms) and to develop new hormonal formulations that are maximally comparable with new microbicides are urgently needed.”

Another study presented in Sydney that utilized data from HPTN 035 found that when examining vaginal fluid samples of a subset of the trial participants, when the vaginal fluid was combined with E. coli, “women who later became HIV infected showed higher activity against the bacteria than those women who remained HIV negative,” according to the MTN release. The investigators said this suggests some kind of underlying level of immune activity that placed them at greater risk of HIV infection – perhaps signifying a new way of identifying women who might be more susceptible to HIV infection.

In other conference news, at the closing plenary session Gina Brown of the Office of AIDS Research and Stephen Becker of the Bill & Melinda Gates Foundation also announced that from 2014 on there will be a single, biennial global HIV prevention conference. Representing the two largest funders of HIV research, Brown and Becker said they  plan to work together to create an integrative prevention meeting reflecting the fact that no one HIV prevention method is likely to end the epidemic.

The International Rectal Microbicide Advocates (IRMA) also released a new report entitled “On the Map: Ensuring Africa’s Place in Rectal Microbicide Research and Advocacy,” that pushes for Africa’s involvement in the area, including clinical trials for safety and efficacy.  The African region has been stunted in its participation in microbicides research due in part to pervasive homophobia, criminalization of homosexual acts and denial of the existence of men who have sex with men in many parts of the region. A group of 40 Africans gathered in Addis Ababa in December 2011 for the Project ARM (Africa for Rectal Microbicides) strategy meeting to develop the document, which “…outlines priority actions to ensure Africa fully engages in rectal microbicide research and advocacy activities, including the integration of safe anal-sex messaging into HIV prevention programs,” according to an IRMA press release.

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