Scientists from Northwestern University have developed a new intravaginal ring that they say could help prevent women from being infected with HIV. The device is easily inserted and remains in place for 28 days, delivering a measured amount of the anti-retroviral tenofovir directly to the site of transmission.
HIV affects an estimated 34 million people around the world. In 2011, 2.5 million people were newly diagnosed, and in sub-Saharan Africa, women make up 60% of people living with HIV/AIDS.
Preventative drugs do exist, but many have proved ineffective, especially in developing countries where financial and cultural barriers interrupt their use.
Previous studies have shown that antiviral drugs can prevent HIV infection, but existing delivery methods often fall short: pills need to be taken daily and in high doses, while vaginal gels have to be applied before each sex act, making them inconvenient.
However, the researchers from Northwestern University believe they have found an answer with their new device.
Visiting associate professor Patrick Kiser, an expert in intravaginal drug delivery, claims the ring is easy to use, long-lasting and extremely effective. He says:
“After 10 years of work, we have created an intravaginal ring that can prevent against multiple HIV exposures over an extended period of time, with consistent prevention levels throughout the menstrual cycle.”
The ring has a unique polymer construction, which allows its elastomer to swell in the presence of fluid, delivering up to 1,000 times more of the drug than current intravaginal devices.
Based on its success in preventing transmission of simian immunodeficiency virus (SIV) in macaques, the ring – known as a TDF-IVR (tenofovir disoproxil fumarate intravaginal ring) – will be tested in a clinical trial at the Albert Einstein College of Medicine in New York in November.
Sixty women will be fitted with the ring, and the trial will assess its safety and measure how much of the drug is used.
Other drugs could be integrated in the TDF-IVR, such as contraceptives and antiviral drugs, to prevent other sexually transmitted diseases, which Kiser believes could increase user rates.
“The flexibility to engineer this system to deliver multiple drugs and change release rates is extraordinary and could have a significant impact on women’s health,” he says.