Navigation Links
Novel intravaginal ring shows promise for HIV prevention
Date:7/2/2014

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.

One of the two drug combinations tested in the ring had been shown in three clinical trials to prevent HIVsome of the timewhen 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.


'/>"/>

Contact: Jim Sliwa
jsliwa@asmusa.org
202-942-9297
American Society for Microbiology
Source:Eurekalert

Related biology news :

1. Novel dark matter searches, identifying muzzle flashes, and more at 2014 APS DAMOP annual meeting
2. A novel disease-preventing antioxidant pathway
3. Novel drug target linked to insulin secretion and type 2 diabetes treatment
4. Illinois researchers combine weak chemical forces to strengthen novel imaging technology
5. Novel RNAi therapy silences mutated Huntingtons disease gene and reduces symptoms
6. Sanford-Burnham and Daiichi Sankyo form alliance to study novel drug targets
7. Novel ORNL technique enables air-stable water droplet networks
8. High-efficiency water treatment using light using a novel UV-light system
9. Novel antioxidant makes old arteries seem young again, CU-Boulder study finds
10. Salk Institute study identifies novel regulator of key gene expression in cancer
11. Novel marker discovered for stem cells derived from human umbilical cord blood
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:11/22/2016)... MINNETONKA, Minn. , Nov. 22, 2016   ... that supports the entire spectrum of clinical research, is ... by Medical LiveWire Healthcare and Life Sciences Awards ... This award caps off an unprecedented year of recognition ... clinical trials for over 15 years. iMedNet ...
(Date:11/16/2016)... , Nov. 16, 2016 Sensory Inc ... and security for consumer electronics, and VeriTran ... and retail industry, today announced a global partnership ... way to authenticate users of mobile banking and ... TrulySecure™ software which requires no specialized biometric ...
(Date:6/27/2016)... 27, 2016 Research and Markets has announced ... report to their offering. ... to grow at a CAGR of 12.28% during the ... on an in-depth market analysis with inputs from industry experts. The ... coming years. The report also includes a discussion of the key ...
Breaking Biology News(10 mins):
(Date:11/30/2016)... Nov. 30, 2016  The Allen Institute for ... the first publicly available collection of gene edited, ... target key cellular structures with unprecedented clarity. Distributed ... powerful tools are a crucial first step toward ... understand what makes human cells healthy and what ...
(Date:11/30/2016)... , Nov. 30, 2016  Tempus, a ... cancer care, and Penn,s Abramson Cancer Center have ... a positive response to immunotherapy treatment based on ... As part of a research collaboration, Tempus ... and melanoma cancer patient data to Penn. Utilizing ...
(Date:11/30/2016)... , 30. November 2016   Merck ... heute die Unterzeichnung einer Reihe von Vereinbarungen ... wird Evotec AG Screeningleistungen für Mercks Palette ... Der Zugriff auf diese Bibliotheken in Kombination ... einen schnelleren Weg zur Ermittlung und Erforschung ...
(Date:11/30/2016)... --  Merck , a leading science and technology company, ... of agreements with Evotec AG, whereby Evotec AG will ... such as CRISPR and shRNA libraries. Combining access to ... pathway to explore and identify new drug targets. ... targets, a process that can be time- and labor-intensive," ...
Breaking Biology Technology: