Avant advance with HIV trial

AVANT Immunotherapeutics and the Walter Reed Army Institute of Research (WRAIR) have initiated a Phase I clinical trial to assess the safety and immunogenicity of an HIV vaccine based on AVANT's Therapore technology.

The placebo-controlled trial is evaluating the vaccine at three escalating dose levels in 18 healthy adult volunteers. The trial, in conjunction with the division of AIDS (DAIDS), National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIAID), US department of health and human resources, is being conducted at the WRAIR vaccine clinical research centre in Rockville, MD. WRAIR and NIAID are working together through an established interagency agreement.

'We are very pleased that WRAIR/DAIDS has initiated human clinical trials of this experimental HIV vaccine, which is based upon AVANT's Therapore technology,' said Dr Una Ryan, president and chief executive officer of AVANT. 'The company believes this technology offers significant advantages over other immunotherapeutic methods.' Therapore will be used to generate cell-mediated immune responses against the HIV gag p24 protein. Experts believe that cell-mediated immune responses may be a necessary attribute of a vaccine to prevent infection by the virus and subsequently to protect individuals from developing Acquired Immunodeficiency Syndrome (AIDS).

The clinical trial is being conducted under a cooperative research and development agreement (CRADA) between AVANT and WRAIR. Under the CRADA, AVANT is providing its proprietary Therapore technology. Volunteers in each of the three dose groups in the study will receive three intramuscular vaccine immunisations or placebo injections at weeks 0, 4 and 16 and will be followed for at least 36 weeks following their final dose.

The WRAIR HIV vaccine, designated LFn-p24, consists of an anthrax-derived polypeptide called Lethal factor (LFn), from which the toxin domain has been removed, and which is fused to the HIV-1 gag p24 protein. The vaccine is aimed at inducing strong and persistent HIV-1 gag specific CD8 T Cell responses.

Therapore utilises bacterial toxin proteins to deliver target antigens into human cells to induce significant cell-mediated immune (CMI) responses. Preclinical research with Therapore has shown its ability to safely induce long-lived CMI responses with great efficiency. In addition, Therapore has demonstrated an ability to deliver large peptides and protein antigens to the immune system, potentially enabling broader vaccine protective coverage in humans. AVANT plans to use its Therapore technology to develop novel immunotherapeutics for the prevention and treatment of chronic viral infections including Hepatitis B, Hepatitis C, and HIV, as well as for the treatment of certain cancers.

HIV facts

HIV, the virus that causes AIDS, was discovered in 1983, following the first recognised cases of AIDS in 1981 and 1982. Since then, the World Health Organisation (WHO) estimates that well over 20m people have died throughout the world as a consequence of this disease. It's currently estimated that 40m people around the world are currently living with HIV and/or AIDS, with 5m of those having become newly infected in 2003. In the United States, over 886,000 cases of AIDS have been reported through 2002, resulting in more than 500,000 deaths. To date there is no approved HIV vaccine.