VaxGen Vaccine Candidate May be Effective Against ‘Broader Array’ of HIV Strains Than First Believed

Vaccine developer VaxGen Inc. announced Tuesday that its HIV vaccine candidate AIDSVAX may produce "immune responses capable of preventing infection from a broader array of HIV strains than previously detected." According to results presented last week at the Cold Spring Harbor 2001 Meeting on Retroviruses, AIDSVAX produced antibodies that "bound" to infected T-cells and prevented the infected cells from infecting healthy cells in four out of five experiments, each of which used a different HIV strain. The results were made possible because of a new assay developed by the company that enables researchers to "more accurately measure" how the antibodies blocked cell-to-cell transmission of HIV. "These are preliminary laboratory results that need additional confirmation, but they are encouraging because they indicate that AIDSVAX induces the type of antibodies necessary to prevent HIV infection in real-life settings," Dr. Donald Francis, president of VaxGen, said. VaxGen has the only preventive HIV vaccine candidate in Phase III trials, the final stage before applying for FDA approval. The company is currently overseeing two trials -- one in Europe and North America and one in Thailand -- with 7,900 volunteers. Results from the North American/European trial, which is nine months ahead of the Thai trial, are expected in November of this year or 2002. "[I]f our Phase III trials demonstrate that AIDSVAX is effective, we believe this assay will be an important tool to help us more rapidly develop vaccines for additional geographic areas," Francis added (VaxGen release, 5/29). News of the assay experiments sent VaxGen's shares up $5 to close at $23.89 Tuesday on the Nasdaq (Bloomberg/Los Angeles Times, 5/30).