London, 27 November 2008 - The International AIDS Vaccine Initiative (IAVI) and the St. Stephen’s AIDS Trust at the Chelsea and Westminster Hospital have initiated a Phase I clinical trial in London, UK to test a prime-boost combination of two HIV vaccine candidates.
“Prevention is crucial in the fight against HIV and AIDS, and a vaccine is one of the most powerful prevention tools we know to combat infectious diseases,” according to Professor Brian Gazzard, Research Director at the St. Stephen’s AIDS Trust and the principle investigator of this trial. “We hope this trial will contribute to a better understanding of how to induce with a vaccine an immune response to protect against HIV infection and AIDS. “
The news follows promising results recently announced by IAVI and partners for one of the two vaccine candidates to be tested, the MVA-based TBC-M4, which in a recent phase I trial generated modest immune responses in all volunteers who received the highest dose. According to Patricia Fast, Chief Medical Officer at the International AIDS Vaccine Initiative, “The responses observed with this vaccine candidate warrant further research to improve immune activation. We have learned from other studies that a prime-boost regimen has the potential to achieve just this.”
That is why the new trial will include a DNA-based vaccine candidate called ADVAX to prime the immune system. Previous Phase I studies with different DNA and MVA-based HIV vaccines in combination have shown that this prime-boost regimen was safe and well tolerated, and also able to generate enhanced immune responses when compared with the responses generated by either vaccine alone. The ADVAX vaccine candidate also offers economic value; it is relatively easy and cheap to manufacture, which makes it particularly appealing for use in the developing world.
A separate Phase I trial testing ADVAX and the MVA-based candidates in a prime-boost regime is planned for India. This trial would use a different mode of administration for the priming vaccine, different dosages and different vaccine regimens. Collectively, the results of both trials will help determine whether further development of both AIDS vaccine candidates in a prime-boost combination is warranted.
Deborah Jack, Chief Executive of the National AIDS Trust, comments: “The UK has always been a leader in the quest for new technologies to prevent HIV. Hosting a vaccine trial in London is a great opportunity to continue doing our part in the global fight against HIV and AIDS. Like any medical development, discovering an HIV vaccine is a naturally long process but when a vaccine is found it could save millions of lives globally, not just in the developing world but also in the UK.”
About the vaccine candidates
The vaccine candidate TBC-M4 is based on a vector built from recombinant Modified Vaccinia Ankara (MVA). It was designed by a biotech firm in the U.S. in collaboration with Dr. Sekhar Chakrabarty from the National Institute of Cholera and Enteric Diseases (NICED) in Kolkata, India . It targets HIV-1 subtype C, the most predominant HIV subtype in India, and contains 6 HIV genes : env, gag, reverse transcriptase, rev, tat and nef.
The vaccine candidate ADVAX is a plasmid DNA vaccine containing HIV-1 subtype C genes env, gag, pol, nef and tat. The vaccine was designed by the Aaron Diamond Research Centre in New York, through collaboration with Rockefeller University in New York and the International AIDS Vaccine Initiative.
It should be noted that since both vaccine candidates contain only synthetic copies of part of HIV’s genetic material, they cannot cause HIV infection.
ADVAX will be administered with a needle-free device (Biojector 2000), and the trial will also assess whether this delivery mechanism provides benefits over regular injection with a needle and syringe. ”Needle-free injection of a DNA vaccine can provide enhanced immune responses compared with administration by needle and syringe,” according to Dr. Richard Stout, Executive Vice President and Chief Medical Officer of Bioject Medical Technologies Inc., manufacturer of the device.
About the trial
The trial is a Phase I randomized, double-blind, placebo-controlled trial. It evaluates the safety and immunogenicity of ADVAX and TBC-M4 vaccines in a prime-boost regimen. The trial is recruiting 32 volunteers who are healthy HIV-negative men and women at low risk for HIV infection. All volunteers must provide full informed consent for their participation in the trial.
In addition to using standard immunology assays to measure the responses following vaccination, the trial will also evaluate a novel viral suppression assay. This assay provides a functional assessment of the immune response by measuring anti-viral activity. “There are indications from previous clinical studies that the laboratory assays currently used in HIV vaccine clinical trials are not an accurate predictor of whether a vaccine can prevent or control HIV infection,” said Dr. Jill Gilmour, Senior Director of Clinical Research at IAVI. “We urgently need to identify which laboratory tests give us insight into whether a person will resist infection with HIV or development of AIDS. This will enable researchers to select the most promising vaccine candidates for large-scale efficacy testing.”
It is expected that the trial will take 14 months to complete. The trial is fully sponsored by the International AIDS Vaccine Initiative.
About AIDS vaccines
An AIDS vaccine is urgently needed to help control the AIDS pandemic and stop the spread of HIV. Worldwide, 33 million people are living with HIV and every day, 7,500 are newly infected with the virus. HIV has proven to be a uniquely complex virus, making the development of a vaccine against it one of the greatest challenges in medicine today. Scientists are following important evidence from the laboratory and from clinical observations that immunity-induced prevention or control of HIV infection is achievable. Worldwide there are almost 30 AIDS vaccine clinical trials ongoing in which around 20,000 volunteers participate.
The International AIDS Vaccine Initiative (IAVI) is a global not-for-profit organization whose mission is to ensure the development of safe, effective, accessible, preventive HIV vaccines for use throughout the world. Founded in 1996 and operational in 24 countries, IAVI and its network of collaborators research and develop vaccine candidates. IAVI's financial and in-kind supporters include the Alfred P. Sloan Foundation, the Bill & Melinda Gates Foundation, the Foundation for the National Institutes of Health, The John D. Evans Foundation, The New York Community Trust, the James B. Pendleton Charitable Trust, The Rockefeller Foundation, The Starr Foundation, The William and Flora Hewlett Foundation; the Governments of Canada, Denmark, India, Ireland, The Netherlands, Norway, Spain, Sweden, the United Kingdom, and the United States, the Basque Autonomous Government as well as the European Union; multilateral organizations such as The World Bank; corporate donors including BD (Becton, Dickinson & Co.), Bristol-Myers Squibb, Continental Airlines, Google Inc., Henry Schein, Inc., Merck & Co., Inc., Pfizer Inc and Thermo Fisher Scientific Inc.; leading AIDS charities such as Broadway Cares/Equity Fights AIDS and Until There's A Cure Foundation; other private donors such as The Haas Trusts; and many generous individuals from around the world. For more information, seewww.iavi.org.
About St. Stephen’s AIDS Trust
St Stephen’s AIDS Trust was founded in 1991 to support clinical research in HIV/AIDS, to improve the quality of life for people living with HIV/AIDS and to share knowledge and experience through education and training. St Stephen's AIDS Trust sponsors a wide variety of important research and clinical trials, performed in its dedicated HIV Research Unit at the Chelsea and Westminster Hospital, improving the care of HIV positive patients and contributing to many major, multicentre studies that continue to revolutionize the treatment of HIV infection. It has a large educational remit, running short courses in HIV and STIs at the Chelsea and Westminster Hospital for healthcare professionals in the UK. In addition, the charity provides HIV workshops and HIV training programmes in resource poor countries. For more information, seewww.ssat.org.uk.
Bioject Medical Technologies Inc., (OTCBB: BJCT) based in Portland, Oregon, is an innovative developer and manufacturer of needle-free injection therapy systems (NFITS). NFITS provide an empowering technology and works by forcing medication at high speed through a tiny orifice held against the skin. This creates a fine stream of high-pressure fluid penetrating the skin and depositing medication in the tissue beneath. The Company is focused on developing mutually beneficial agreements with leading pharmaceutical, biotechnology, and veterinary companies. For more information about Bioject, visit: www.bioject.com.