Featured Research

from universities, journals, and other organizations

Novel intravaginal ring shows promise for HIV prevention

Date:
July 2, 2014
Source:
American Society for Microbiology
Summary:
A novel intravaginal ring implanted with anti-retroviral drug tablets, or pods, demonstrated sustained and controlled drug release and safety over 28 days, according to a study. The ring, designed to prevent transmission of HIV, was tested in pig-tailed macaque monkeys, and is engineered to be inexpensive, all the better for use in developing countries, says a corresponding author.

A novel intravaginal ring implanted with anti-retroviral drug tablets, or pods, demonstrated sustained and controlled drug release and safety over 28 days, according to a paper published ahead of print in Antimicrobial Agents and Chemotherapy. The ring, designed to prevent transmission of HIV, was tested in pig-tailed macaque monkeys, and is engineered to be inexpensive, all the better for use in developing countries, says corresponding author Marc Baum.

Related Articles


One of the two drug combinations tested in the ring had been shown in three clinical trials to prevent HIV -- some of the time -- when taken orally, and is the only product approved by the US Food and Drug Administration (FDA) for HIV prophylaxis.

The ring's topical drug delivery has critical advantages over oral therapy. People often fail to take their medications as prescribed. That probably accounts for some of the wide variation in risk reduction in the three clinical trials, which ranged from 44 to 75 percent, says Baum, of the Oak Crest Institute of Science, Pasadena, CA. "Issues such as adherence to a regular dosing schedule are significantly reduced by continuous release of the drugs into the vaginal mucosa independently of coitus and daily dosing."

"The ring maintained steady state drug levels in the vaginal tissues, the key anatomic compartment for preventing sexual HIV transmission, and eliminated the concentration troughs encountered with oral medications," says Baum. "This should boost effectiveness." These tests, in the monkeys, were performed by James M. Smith's group at the Centers for Disease Control and Prevention, Atlanta.

"In addition, systemic levels are so low as to usually be undetectable in topical delivery," says Baum. "That means that side effects are dramatically reduced, or eliminated entirely."

The ring is a simple, unmedicated, impermeable elastomer scaffold on which the investigators implanted polymer-coated drug tablets, each containing a different drug. These deliver the drug directly to the vaginal mucosa, via channels in the elastomer ring, which exposes the pods to vaginal fluids.

An additional requirement for safety and efficacy is that the ring must not trigger immune defenses, and their associated inflammation, as that could encourage HIV infection by compromising the integrity of the mucosal barrier, as well as by recruiting and activating immune cells that are the virus's targets. And in fact, the immune system, and the vaginal microbiome were undisturbed.

Baum notes that the pig-tailed macaque model is an ideal surrogate for humans. "The model has similarities with the human menstrual cycle, vaginal architecture and vaginal microbiome, and the ability to conduct efficacy studies with simian-human immunodeficiency virus," he says.

"Macaques cannot be infected with HIV, so scientists have developed a hybrid virus, simian-human immunodeficiency virus, that infects the monkeys and leads to a disease much like AIDS," Baum explains. This virus contains parts of the human immunodeficiency virus, and is susceptible to many HIV drugs, he says. "This is the state of the art for studying HIV/AIDS in vivo."

The two drug combinations tested include Truvada, which consists of emtricitabine and tenofovir disoproxil fumarate, and Truvada plus maraviroc, which works by blocking the chemokine receptor, CCR5, which is a target entryway of HIV.


Story Source:

The above story is based on materials provided by American Society for Microbiology. Note: Materials may be edited for content and length.


Journal Reference:

  1. J. A. Moss, P. Srinivasan, T. J. Smith, I. Butkyavichene, G. Lopez, A. A. Brooks, A. Martin, C. T. Dinh, J. M. Smith, M. M. Baum. Pod-intravaginal rings delivering antiretroviral combinations for HIV prophylaxis: pharmacokinetics and preliminary safety in a macaque model. Antimicrobial Agents and Chemotherapy, 2014; DOI: 10.1128/AAC.02871-14

Cite This Page:

American Society for Microbiology. "Novel intravaginal ring shows promise for HIV prevention." ScienceDaily. ScienceDaily, 2 July 2014. <www.sciencedaily.com/releases/2014/07/140702140633.htm>.
American Society for Microbiology. (2014, July 2). Novel intravaginal ring shows promise for HIV prevention. ScienceDaily. Retrieved March 6, 2015 from www.sciencedaily.com/releases/2014/07/140702140633.htm
American Society for Microbiology. "Novel intravaginal ring shows promise for HIV prevention." ScienceDaily. www.sciencedaily.com/releases/2014/07/140702140633.htm (accessed March 6, 2015).

Share This


More From ScienceDaily



More Health & Medicine News

Friday, March 6, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Bupa Eyes India Healthcare Opportunities

Bupa Eyes India Healthcare Opportunities

Reuters - Business Video Online (Mar. 5, 2015) Bupa is hoping to expand in India&apos;s fast-growing health insurance market, once a rule change on foreign investment is implemented. The British private healthcare group&apos;s CEO tells Grace Pascoe why it&apos;s so keen on the new opportunity. Video provided by Reuters
Powered by NewsLook.com
Liberia Releases Last Ebola Patient, But Threat Remains

Liberia Releases Last Ebola Patient, But Threat Remains

Newsy (Mar. 5, 2015) Liberia&apos;s last Ebola patient has been released, and the country hasn&apos;t recorded a new case in a week. However, fears of another outbreak still exist. Video provided by Newsy
Powered by NewsLook.com
Doctor in Your Pocket Is Getting Smarter

Doctor in Your Pocket Is Getting Smarter

Reuters - Business Video Online (Mar. 5, 2015) Mobile apps are turning smartphones into a personal doctors, with users able to measure heart rate, blood pressure and even blood sugar. But will it change our behaviour? Ivor Bennett reports from the Mobile World Congress in Barcelona. Video provided by Reuters
Powered by NewsLook.com
AbbVie Inks $21B Deal To Buy Cancer Drugmaker Pharmacyclics

AbbVie Inks $21B Deal To Buy Cancer Drugmaker Pharmacyclics

Newsy (Mar. 5, 2015) AbbVie announced Wednesday it will buy cancer drugmaker Pharmacyclics in a $21 billion deal. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins