Induction of Immunogenicity With Different Doses of Grass MATA in Subjects Allergic to Grass and Rye Pollen

Grass MATA MPL has been developed to provide pre-seasonal specific immunotherapy for patients with proven type I hypersensitivity to cross reacting grass pollens. The grass pollen extract is modified with glutaraldehyde to produce the active ingredient, an allergoid. This modification reduces the reactivity of the extract with IgE antibody, thus reducing the risk of side effects. However, a simultaneous reduction in other important immunological properties, such as IgG and T cell reactivities, is not seen. MPL (Monophosphoryl Lipid A), a purified, detoxified glycolipid derived from the cell wall of Salmonella minnesota, is included in the product formulation as an adjuvant to increase the immunogenic effect of the product and to enhance the switch from an allergen-specific TH2 to a TH1-like T cell profile. The purpose of this study is to assess specific immunological changes (IgG, IgG1, IgG4 and IgE) in allergic subjects following 2 subcutaneous injections of different doses of study medication (Grass MATA or placebo) administered 3 weeks apart. The immunological changes will be used to assess the performance of the R7 IgG reactivity assay over a range of clinically efficacious doses.