Women may someday have a new birth control option designed to not only prevent unplanned pregnancy but also block the transmission of the HIV virus. Researchers from Weill Cornell Medical College (New York) have published results showing that a new contraceptive device may do just that. The results are published in the latest issue of the journal AIDS.

The new device is a vaginal ring that releases multiple types of non-hormonal agents and microbicides, which would prevent conception as well as sexually transmitted HIV infection, according to the researchers.

Worldwide, there are about 5 million new infections and 3 million deaths a year due to HIV/AIDS. If proven successful in future clinical trials, the new device could empower women to effectively and conveniently protect themselves from unintended pregnancy and sexually transmitted infection. The ring may also someday represent a novel method to prevent sexually transmitted infections for those with aversion to currently available methods, with hormonally derived active agents, or with allergies to latex condoms, the researchers said.

"This device is a new approach to birth control, because it avoids the long-term use of hormonal methods that have been associated with increased risk of certain cancers," said Brij Saxena, MD, lead author and the Harold and Percy Uris Professor of Reproductive Biology and professor of endocrinology in the department of obstetrics and gynecology at Weill Cornell Medical College. "At the same time, this is the first device to simultaneously offer the possibility to prevent unintended pregnancy and HIV transmission."

Saxena told Medical Device Daily that long-term use of hormones have side effects. Women are always at risk for infection with HIV, he said, because it is transmitted during heterosexual contact. With this vaginal ring, "women will have control themselves to protect them [from] unintended pregnancy and HIV infection.

He said the device can provide sustained release of both contraceptives and microbicide simultaneously in vitro at the concentration "which is efficacious and significantly below the toxic levels."

The vaginally inserted ring is incorporated with multiple antiviral drugs that prevent HIV infection and are time-released over a period up to 28 days. The compounds tested were a newly developed anti-HIV agent, Boc-lysinated betulonic acid, TMC120 (dapivirine), PMPA, and 3'-azido-3'-deoxythymidine (AZT or zidovudine), which, when combined, were found to block infection in human cells exposed to the virus in a laboratory setting.

"No one has ever conquered a viral epidemic with treatment, so prevention is the most effective option. Ideally, an HIV vaccine is the most desirable method, but that is not foreseeable in the near future," said Jeffrey Laurence, MD, co-author of the study and attending physician at NewYork-Presbyterian Hospital/Weill Cornell Medical Center. "The next best thing would be something that would prevent infection and put the power in the susceptible female partner's control. That's the potential a device such as this can offer."

When asked to provide a crystal ball guess as to when this new device might be available to women in the U.S., Saxena said it may be a couple of years. He said the compounds used in the device are natural materials that are already FDA approved for human use. However, the device itself may still be subject to FDA approval, he noted.

"The combination of these antiviral drugs has proven to be potent agents that may block infection by the HIV virus," Saxena said.

The ring is also incorporated with compounds that prevent conception by arresting sperm motility, raising vaginal mucous viscosity, and sustaining the acidity of the vagina in which sperm do not survive. Traditionally, similar devices have used hormonal compounds that have been linked to increased risk of breast and cervical cancers, or spermicidal compounds that kill sperm, but may lead to irritation and inflammation, according to the researchers. Past findings published in the journal Contraception found the device to be highly effective in animal models and in laboratory testing.

The study was supported by grants by the National Institutes of Health, International Partnership for Microbicides (Silver Spring, Maryland) and BioRings. Collaborators on the study include Dr. Young Han and Mukul Singh, PhD, from Weill Cornell Medical College, Dr. Dingyi Fu and Dr. Premila Rathnam, formerly of Weill Cornell, and Sidney Lerner from BioRings.

Saxena and Singh are vice presidents at BioRings and along with Lerner, president of BioRings, are co-inventors and owners of U.S. and foreign patents on the technology used in this research. Cornell Research Foundation owns pending patent applications related to the research.