human Fcγ1-Fel d1 fusion protein

Human Fcγ1-Fel d1 fusion protein (GFD) is an experimental recombinant fusion protein developed by the National Institute of Allergy and Infectious Diseases (NIAID) in collaboration with researchers at UCLA for the treatment of cat allergy. The biologic is composed of the human IgG1 Fc region (hinge through CH3) fused to Fel d1, the major cat allergen protein. GFD works through a novel mechanism of co-crosslinking the inhibitory receptor FcγRIIb with the high-affinity IgE receptor (FcεRI) on the surface of mast cells and basophils. This interaction triggers inhibitory signaling that prevents the release of inflammatory mediators, thereby blocking the allergic cascade without inducing degranulation itself. The drug has been evaluated in a Phase 0 dose-escalating clinical trial to assess its safety and ability to block cutaneous reactions to cat allergen exposure.

Other names

GFD fusion proteinhuman Fc gamma 1-Fel d1 fusion protein