IgEG Platform


Combining IgE and IgG Functionality

  • Epsilogen has combined the powerful functionalities of IgE and IgG antibody isotypes
  • IgE and IgG are related but structurally/functionally different antibodies

IgEGs: Hybrid IgE/IgG Antibodies

By fusing the CH2-CH3 domains plus the hinge region of IgG to the C terminus of an IgE molecule to create an IgEG

IgEG antibodies have the potential for very high potency by:

  • Activating myeloid effector cells such as basophils and macrophages by binding IgE receptors
  • Activating Natural Killer (NK) cells by binding Fcg receptors
  • Fixing complement
  • Possessing extended serum half life by pH-dependent binding to FcRn

In vitro Proof of Concept established

  • Express well, fold correctly and bind antigen
  • Activate immune cells via engagement with Fcγ receptors
  • Activate immune cells via engagement with Fcε receptors
  • Bind to FcRn in pH-dependent fashion
    Drive both ADCC and ADCP responses

In vivo Proof of Concept established

  • NXG mouse/PBMC model with JIMT 1 cell challenge (HER2 low)
  • Anti-HER2 IgEGs showed statistically significant tumour growth inhibition (TGI)
  • IgEGs work at much lower doses than the equivalent IgG in the NXG mouse model

Half life extension demonstrated in transgenic mouse model

  • IgEGs possess greatly elevated serum half life versus IgE
  • IgEGs successfully combine long tissue half life of IgE with elevated serum half life of IgG