grass pollen allergen extract (National Institute of Allergy and Infectious Diseases)

Grass pollen allergen extract is a biological therapeutic used for subcutaneous immunotherapy (SCIT) in patients with moderate to severe seasonal allergic rhinitis. In the context of the GRASS (Grass Pollen Sublingual vs Subcutaneous Immunotherapy) clinical trial (ITN043AD), sponsored by the National Institute of Allergy and Infectious Diseases (NIAID) and conducted through the Immune Tolerance Network (ITN), this extract was administered via subcutaneous injection to evaluate its ability to induce long-term immune tolerance. The mechanism of action involves the gradual desensitization of the immune system through repeated exposure to standardized allergens, typically derived from Timothy grass (Phleum pratense). This process modulates the immune response by inducing regulatory T-cells (Tregs), shifting the cytokine profile from a Th2-biased allergic response to a Th1-mediated response, and stimulating the production of allergen-specific IgG4 'blocking' antibodies, which compete with IgE to prevent mast cell and basophil activation.

Other names

subcutaneous immunotherapySCITgrass pollen SCITGRASS trial SCIT armTimothy grass pollen allergen extract