New study on microbicide vaginal ring to prevent HIV

A new clinical trial in the area of HIV prevention for women is underway in South Africa. It is known as "The Ring Study" and it will test the long-term safety and preventive efficacy of an antiretroviral drug, dapivirine, when this is contained in a vaginal ring that releases the drug into the vagina in a sustained manner. The Ring Study will explore whether a vaginal ring containing dapivirine, which is changed monthly, is safe to use and whether it can protect women from contracting HIV-1. The Ring Study - the first efficacy trial of a ring for HIV prevention - is being conducted by the non-profit International Partnership for Microbicides (IPM) and is more formally known as IPM 027.

 In South Africa, after obtaining regulatory and ethics approvals, the trial is taking place at research centres in the North West and KwaZulu-Natal provinces. The approval of national regulators and independent ethics committees has been sought to initiate the Ring Study in other countries, including Rwanda and Malawi. Dr Zeda Rosenberg, CEO at IPM, explained that the Ring Study presented an important technological advancement. She said the ring might provide protection not only because of the active drug but also because women only needed to put the ring in once a month, so it stayed in the body and could offer protection throughout this time. Condoms remain the most effective way to protect partners from HIV during sex. Yet there are challenges associated with condom use, which in many instances depends on the male partner's willingness to wear a condom during intercourse.

Approximately 1,650 women will participate in the Ring Study. Of these, 1110 will be in the group that uses the dapivirine ring, and 550 women will be in the placebo group which will use a similar vaginal ring but without the active drug. Women will be randomly assigned to the two groups and neither the women nor the researchers will know which product is being used by individual participants. At the end of the study, the two groups of women will be compared to see if there were fewer HIV-1 infections among women using the dapivirine ring than among those using the placebo, and if the ring was safe when used for an extended period. Antiretroviral drugs have been used successfully for years in the treatment of HIV/AIDS and in prevention of mother-to-child transmission of HIV.

Recent research has shown the great potential for ARVs to be used more widely to prevent HIV. Dapivirine belongs to a class of ARVs known as non-nucleoside reverse transcriptase inhibitors, or NNRTIs, which have long been used to successfully treat HIV-1 and prevent mother-to-child transmission. Dr Annalene Nel, chief medical officer at IPM, said small safety studies had shown that microbicide rings, which women use for a month at a time, were comfortable and easy to use, and were not usually felt by either partner during sex.

Similar rings were in use in many countries as a contraceptive delivery method. Nel said the Ring Study protocol had received all necessary approvals from South African and other international regulatory authorities. She said that, as was best practice in clinical trials, an independent Data Safety Monitoring Board (DSMB) would conduct regular reviews of the study data to ensure the ethical conduct of the trial and that the safety of participants was maintained at all times.

Women and communities near study sites are being educated about participating in the study. Participation is voluntary and women can exit from the study at any time and for any reason. Participants receive information about HIV and are counselled to use condoms and contraceptives throughout the study period. Their partners are also encouraged to become involved.

In a separate larger study, known as ASPIRE or MTN-020, the Microbicide Trials Network (MTN) will soon begin testing the same ring in a sample of nearly 3,500 women in southern Africa. Dr Sharon Hillier, principal investigator of the MTN, said sustained delivery of antiretrovirals in a vaginal ring could be a game-changer for prevention of HIV in women. She said the MTN's partnership with IPM on the effectiveness studies of this new technology would provide the most rapid and efficient pathway to licensure of this HIV prevention product. Results of both studies are expected to be available in 2015. Should the dapivirine ring prove to be safe and to offer protection to women, IPM - as the developer of this technology - will work with regulatory authorities to license the ring.

If the dapivirine ring is approved by regulators, IPM is committed to providing the ring at the lowest possible cost and partnering with other organisations to ensure it reaches women who are most at risk of HIV in developing countries, especially sub-Saharan Africa. More than 15 million women are living with HIV/AIDS worldwide. In sub-Saharan Africa, the region hardest hit by the epidemic, women account for 60 percent of people living with HIV. New HIV prevention strategies that women can use themselves - such as microbicides - are therefore urgently needed.

Health-e News Service, 26 June 2012