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:1/11/2016)... 11, 2016  higi, the leading retail and ... locations, web and mobile, today announced it has ... existing investors. --> ... further innovate higi,s health platform – its network ... – including expanding services and programs to retail ...
(Date:1/7/2016)... This BCC Research report studies the global ... devices, identifying newer markets and exploring the expansion of ... devices. Includes forecast from 2015 to 2020. ... explore the expansion of the present application market for ... biometric technology, determine its current market size, and estimate ...
(Date:1/6/2016)... PLEASANTON, Calif. , Jan. 6, 2016  Varam ... SayPay as their trusted partner to deliver advanced authentication ... other financial services to the poor. A loan of ... in their lives, giving them the ability to purchase ... machine to make clothing, or stock for a local ...
Breaking Biology News(10 mins):
(Date:2/4/2016)... -- - New FDA action date of July ... date of July 22, 2016   --> ... 2016   - Lifitegrast has the potential ... the treatment of signs and symptoms of dry eye disease in ... be the only product approved in the U.S. in the past decade indicated for the ...
(Date:2/4/2016)... Falls Church, VA (PRWEB) , ... ... ... a first-year cybersecurity conference presented by Bloomsburg University’s Digital Forensics Club, takes ... Bloomsburg, PA. The two-day event features 20+ speakers and activities such as ...
(Date:2/4/2016)... MENLO PARK, Calif. , Feb. 4, 2016 ... the "Company"), a biopharmaceutical company focused on the development and ... present at the 18 th Annual BIO CEO ... 10:00 a.m. EST in New York, NY ... CEO, will provide an update on the ongoing clinical trial ...
(Date:2/4/2016)... , Feb. 4, 2016  Spherix Incorporated (Nasdaq: ... the fostering and monetization of intellectual property, today provided ... Uniden in the Northern District of Texas ... forward.  Inter Partes Re-examination ("IPR") ... Patent Office.  The IPR was initiated on only certain ...
Breaking Biology Technology: