Vaccine Adjuvant Produces High Levels of Antibodies in Clinical Trial

At the XIII International AIDS Conference in Durban, South Africa last week, researchers from the University of Rochester (Rochester, NY) presented results from a human study of Aquila Biopharmaceuticals Inc.'s (Framingham, MA) proprietary vaccine adjuvant, QS-21. In clinical trials, QS-21 and substantially reduced amounts of the HIV gp120 antigen produced high levels of antibodies in humans. These results suggest that QS-21 may enable the development of HIV vaccines with significantly lower manufacturing costs, as well as a single vaccine effective against multiple HIV strains.

According to Alison Taunton-Rigby, the study indicates that the use of QS-21 significantly reduces the amount of antigen required for immunogenicity, a finding that has important implications for reduction of HIV vaccine cost and for the development of a truly global vaccine against multiple HIV strains. "The trial is one of several studies that highlight the potential of QS-21 to allow the development of safe and effective vaccines for a number of infectious diseases and cancers," she added.

The study, carried out in 60 HIV negative volunteers, evaluated vaccines containing either 0.5 or 3 ug of a monovalent gp120 formulation or 6 ug of a bivalent gp120 formulation, along with QS-21 or a placebo. The vaccines were administered at the start of the trial and at three and six months following the first injection. The immunogenicity of these low antigen dose vaccines was shown to be similar to those achieved historically with 100 ug or more of gp120 in aluminum hydroxide adjuvant. The two highest individual titers, observed after the completion of the immunization series, were from individuals in the lowest antigen dose group (0.5 ug).

The HIV-1 gp120 antigen used in the study was supplied by VaxGen (Brisbane, CA). VaxGen's HIV vaccine, AIDSVAX, which is currently being evaluated in Phase III clinical trials, contains gp120 and uses alum as the adjuvant. VaxGen has royalty-bearing licenses from Aquila for both gp120 and QS-21.

Aquila Biopharmaceuticals Inc. is a life sciences company developing and commercializing a range of proprietary products that enhance the immune response in animals and humans. The cmpany's products are intended for use in treating, controlling, nd preventing infectious diseases, cancers and autoimmune disorders.

For more information: Aquila Biopharmaceuticals Inc., 175 Crossing Blvd., Framingham, MA 01702. Tel: 508-628-0100. Fax: 508-766-2705.

Edited by Jim Pomager