Vical's Herpes Vaccine: An Update

With the failure of its Allovectin immunotherapy for multiple melanoma and the refocus of the company's resources on vaccines, Vical (VICL) finally provided some long-awaited information on the forthcoming Phase 1/2 trial of the company's herpes simplex virus type 2 or HSV-2 vaccine. As the company discussed at yesterday's Baird 2013 Health Care Conference in New York, the first human trial of its HSV-2 vaccine will commence in the United States toward the end of this year, and will enlist approximately 150 HSV-2 positive adults with a history of symptomatic genital herpes lesions.

For readers who are not familiar with the disease, the figure below, courtesy Vical, presents an overview of the herpes simplex virus type 2.

(click to enlarge)

I presented detailed overviews regarding this vaccine's development in August 2011, February 2012 and February 2013. Of the two serotypes identified, HSV-1 and HSV-2, the former is more common in the United States, but the latter is considered more serious. HSV-2 is a sexually transmitted virus which is the leading cause of genital herpes. According to Medscape, approximately 65% of the United States population is seropositive for HSV-1 by the fourth decade of life. As well, approximately 25% of the United States population is seropositive for HSV-2 by the fourth decade of life, with women being infected more frequently than men. The indirect and direct costs of incident HSV genital infection in the United States are presently approximately $1.8 billion and expected to be greater than $2.7 billion by the year 2015.

Currently, there is no cure for genital herpes. It is a recurrent, lifelong viral infection. But under a grant from the National Institute of Allergy and Infectious Diseases Division of the National Institutes of Health (NIH), the effort mounted by Vical is directed at developing a plasmid DNA-based vaccine to inhibit recurring lesions in patients latently infected with HSV-2. The vaccine also is intended to reduce viral shedding to help prevent transmission to others. And while still in the preclinical stage, results have shown a reproducible statistically significant reduction in viral lesion occurrence in guinea pigs latently infected with HSV-2.

Vical's HSV-2 DNA vaccine program, as seen below, involves collaboration with Lawrence Corey's group at the Fred Hutchinson Research Center. As well, the company is working with researchers at the University of Washington. Several proof-of-concept efforts have demonstrated the efficacy of the approach to be used.

(click to enlarge)

As to the trial design, the 150 adults enlisted in the study first will undergo 2 months of observation to collect shedding data. This will be followed by three monthly injections of the vaccine. A 2-month observation period will close out the trial regimen. The company expects the trial to enlist quickly, given the overwhelming interest in the program.

(click to enlarge

Current estimates suggest that a therapeutic HSV-2 vaccine could generate as much as a billion dollars in annual sales at its peak.

Technical Analysis

As seen in the Daily chart below (courtesy StockCharts.com), Vical's presentation has spurred interest on the Street. The shares have broken the issue's downtrend (which in large part was caused by a major investor liquidating portions of his position) and have apparently begun a technical recovery. The shares remain oversold, though the MACD is positive.

The weekly data also show an oversold stock, with a negative MACD.

Disclosure: I am long VICL. I wrote this article myself, and it expresses my own opinions. I am not receiving compensation for it (other than from Seeking Alpha). I have no business relationship with any company whose stock is mentioned in this article. (More...)

Additional disclosure: I am long VICL. I am not a registered investment advisor and do not provide specific investment advice. The information contained herein is for informational purposes only. Nothing in this article should be taken as a solicitation to purchase or sell securities. Before buying or selling any stock you should do your own research and reach your own conclusion. It is up to investors to make the correct decision after necessary research. Investing includes risks, including loss of principal.

View the original article here

Experimental drug tackles both HIV and genital herpes

Featured Article
Academic Journal
Main Category: HIV / AIDS
Article Date: 25 Jul 2013 - 14:00 PDT Current ratings for:
Experimental drug tackles both HIV and genital herpes

Scientists are developing a drug that may be effective in treating two sexually transmitted infections at once - HIV and genital herpes - as well as potentially preventing the spread of HIV from one person to another.

Researchers from the University of Leuven (KU Leuven) in Belgium say the experimental drug, dubbed PMEO-DAPym, can tackle both HIV (human immunodeficiency virus) and HSV (herpes simplex virus). The drug can prevent HIV from multiplying, making the cells targeted by the virus less susceptible to infection.

The researchers say that both HIV, the virus that causes AIDS, and HSV, the virus that causes genital herpes, can together have dangerous effects. People with genital herpes are more likely to become infected with HIV. Additionally, the scientists say, for people who carry both viruses, one infection can worsen the symptoms of the other. These people are also more likely to infect their partners.

There are drugs already on the market that are both anti-HIV and anti-HSV - tenofovir and adefovir. But the researchers say these drugs do not have the ability to stop the spread of the HIV virus as well as targeting particular cells.

PMEO-DAPym can do this by effectively "down-modulating" the CCR5 receptor. This a molecule on the surface of human immune cells that the HIV virus exploits to enter and infect the cells.

Jan Balzarini of KU Leuven says:

"We are excited about this finding since the concomitant action of one single drug on two different targets in the HIV infection process makes it a multifunctional drug that might eventually result in more efficient suppression of virus replication and a lesser risk of resistance development."

In comparing the effectiveness of PMEO-DAPym against other HIV and HSV drugs already on the market, the researchers say that PMEO-DAPym was equal to or better than tenofovir and adefovir in the majority of the tests.

When testing PMEO-DAPym in a panel of clinical HIV and HSV isolates that were resistant to the currently available drugs, the new antiviral was effective against all of them.

The drug was less effective against HSV compared with acyclovir, a popular anti-HSV drug. But the researchers claim that PMAO-DAPym would still prove effective in the higher concentrations that can be achieved in topical preparations.

As well as being tested against the HIV and HSV viruses themselves, the researchers also tested the new antiviral on cells, tissues and animals prior to exposure to the viruses.

A relative of PMEO-DAPym, tenofovir, has been shown in previous clinical trials, the researchers say, to have an effect as a "vaginal microbicide" - a gel that can be applied to the vagina before sex, helping to protect women against infection.

They add that this suggests PMEO-DAPym might also be developed as a prevention tool against HIV and HSV.

Based on results that proved the drug to be effective against infection of cells through the CCR5 receptor, the researchers say that in addition to blocking multiplication of the virus, making the human mucosal tissue harder to infect could also be a route to effective prevention of HIV transmission.

Before a decision is reached on whether the drug will be approved for clinical trials in humans, it must first be tested in a "relevant microbicidal animal model." The researchers add that its application as a systemic treatment following infection also needs to be investigated.

Written by Honor Whiteman

Copyright: Medical News Today
Not to be reproduced without permission of Medical News Today Visit our hiv / aids section for the latest news on this subject. A multi-targeted drug candidate with dual anti-HIV and Anti-HSV activity, PLoS Pathog 9(7): e1003456. doi:10.1371/journal.ppat.1003456. Open-access journal article. Please use one of the following formats to cite this article in your essay, paper or report:

MLA

Whiteman, Honor. "Experimental drug tackles both HIV and genital herpes." Medical News Today. MediLexicon, Intl., 25 Jul. 2013. Web.
26 Jul. 2013. APA

Please note: If no author information is provided, the source is cited instead.

'Experimental drug tackles both HIV and genital herpes'

Please note that we publish your name, but we do not publish your email address. It is only used to let you know when your message is published. We do not use it for any other purpose. Please see our privacy policy for more information.

If you write about specific medications or operations, please do not name health care professionals by name.

All opinions are moderated before being included (to stop spam). We reserve the right to amend opinions where we deem necessary.

Contact Our News Editors

For any corrections of factual information, or to contact the editors please use our feedback form.

Please send any medical news or health news press releases to:

Note: Any medical information published on this website is not intended as a substitute for informed medical advice and you should not take any action before consulting with a health care professional. For more information, please read our terms and conditions.

View the original article here