VivaGel^® – Clinical Trials Under Way
VivaGel^®, Starpharma's lead product, is a vaginal microbicide gel under development for the prevention of sexually transmitted infections (STIs), including genital herpes and HIV infection. The VivaGel^® product concept is designed to offer a safe, convenient and affordable means for women to protect themselves from infection with genital herpes and HIV during sex. Surveys show that there is substantial demand in North America and Europe for such a product with an estimated billion dollar market for STI prevention products in the developed world.

Studies have shown that individuals who do not use condoms are aware of the need for protection from HIV and other STIs but do not adopt them because of their effects on intimacy and sensitivity during intercourse. VivaGel^® is under development as a product that would be discreetly applied by a woman before intercourse, therefore overcoming these perceived issues with condom use.

Clinical trials have shown VivaGel^®  to be safe for further trials, well tolerated and suitable for development as a vaginal microbicide.

A two-site expanded safety trial of VivaGel^® for prevention of genital herpes has been conducted in San Francisco, US and Kisumu, Kenya. This trial of 54 sexually abstinent women found that VivaGel^® was safe and well tolerated when administered vaginally, twice daily for 14 days. This National Institutes of Health (NIH) supported trial extends the duration of use for VivaGel^® and is the first international trial of this product.

A further trial of the safety and acceptability of VivaGel^® in sexually active young women is being conducted in Florida and Puerto Rico by the Microbicide Trials Network.

VivaGel^® has been awarded US$20.3 million from the US-based National Institutes of Health to develop its HIV indication. The NIH also made an additional award to develop its HSV-2 (genital herpes) indication. VivaGel^® was granted Fast Track status by the US FDA in 2006 as a product for prevention of HIV infection. This designation will accelerate the clinical and regulatory development path. Our microbicide program has received further support in other areas including a US$5.4 million grant from the NIH to develop combination microbicides in collaboration with ReProtect Inc.

The human papillomavirus (HPV) will become the third disease area under investigation for VivaGel^® following encouraging pre-clinical data. Genital HPV is the most common STI infection in the US, with 6.2 million people newly infected each year.

Starpharma has identified several potential line extensions for the gel. These include both the combination gel mentioned above and condom coatings. The commonly used coating on premium condoms is Nonoxynol 9 (N-9), which has spermicidal properties. However, because of its detergent nature, N-9 has been shown to increase the risk of infection with HIV and other viruses such as HSV-2. Starpharma has signed agreements with two leading condom companies to develop VivaGel^® as a condom coating. For regulatory reasons, the approval process for VivaGel^® in this application may offer a faster route to market than the stand-alone gel.

Potential as a Contraceptive
In an independent study undertaken at Johns Hopkins University in the USA, the active ingredient in VivaGel^®, SPL7013, exhibited a potent contraceptive effect when tested in animals. If the results were replicated in humans, then the combination of VivaGel^® as a preventive of genital herpes and HIV infection, and also as a contraceptive, could add greatly to the product's value to sexually active women.

Sexually Transmitted Infections - The Market
VivaGel^® is designed to offer safer sex. It has the potential to prevent transmission of genital herpes (HSV-2), HIV and other STIs. It is intended to be used throughout a woman's active sexual lifetime. In addition to the personal benefit that an individual would gain by remaining free of these diseases, VivaGel^® could reduce the financial burden on the health systems of the world if successful. For example, in the US, HIV and AIDS have “Direct medical costs of up to $15.5 billion per annum” (Source: Mircobicide Development Act). This means that both individuals and governments may be motivated to pay for the product if it fulfils its promise as an effective microbicide.

Independent research has been conducted on the likelihood that women will use a suitable microbicide. For example the article, “Microbicide Preference Among Young Women in California” published in April 2006 in the Journal of Women's Health found that more than 40% of young American women indicated intent to buy a microbicide.

Studies across a wide range of countries have shown strong levels of interest in microbicides (at 5 times the cost of a condom) by women.

HSV-2
In the US, approximately 45 million Americans (26% of women and 18% of men) are infected with HSV-2, the causative agent of genital herpes. Genital herpes is the unrecognised pandemic of the industrialised world. Many patients are asymptomatic and pass on the virus unknowingly. In addition to the painful ulcers caused by HSV-2, patients often develop depression and anxiety. The presence of HSV-2 increases a person's risk of HIV infection by four to eight times. HSV-2 remains in affected nerve cells throughout life and can be activated to produce symptoms intermittently in some infected individuals. There is no cure for genital herpes. Ulcers typically last 3-4 weeks and may occur 4-5 times each year in affected patients. Ulcerative episodes can be suppressed by daily doses of anti-virals, but these are expensive.

Genital herpes is the most common cause of ulcerative genital disease in the US. The prevalence is estimated at between 15 - 25% across all countries with a 16% rate in women in Australia (12% overall). The incidence rate of genital herpes has risen rapidly, and without intervention the prevalence in the US is expected to increase to 39% of men and 49% of women by 2025. The estimated cost of genital herpes in the US is over US$1.5 billion per year.

HIV
In the US, AIDS is now the number one cause of death among African-American women between the ages of 25 and 34. HIV infects more than 40 million people worldwide. About half of those infected are women and transmission by heterosexual intercourse is thought to cause 90% of cases. Seven thousand women are newly infected with HIV each day.

In the developed world, the relative proportions differ from worldwide figures. For example, in the US, more than 1 million people live with HIV. This figure includes 200,000 women, of whom about 65% were infected through heterosexual contact. By the end of 2004, nearly 15,000 Australians were infected with HIV. The medical cost of HIV in the US alone is in the region of US$15 billion per year.

Existing preventative measures for HIV such as condoms, have proved ineffective in stemming the rate of infection and over 50 potential HIV vaccines have failed to provide protection. It is estimated that an effective vaccine is many years away.

For more information about VivaGel^®, download the VivaGel^® flyer
or contact us.