Prior to in-licensing and focussing on the Deoxymab platform, Patrys developed a suite of IgM antibodies. The most advanced product candidate, PAT-SC1, was out-licensed to Hefei Co-source Biomedical Co. in 2015, with an exclusive development and commercialisation deal for all oncology indications in China.  Patrys retains the right to develop and commercialise PAT-SC1 outside of China.

PAT-SC1’s target/antigen, CD55PAT-SC1, is an isoform of the membrane-bound CD55 (DAF-B) (“wild-type CD55”). CD55PAT-SC1 has been shown to be significantly over-expressed on the membrane of gastric cancer tissues (74%), while no expression has been detected on healthy cells and tissues.

While Patrys is the only company to identify a cancer-specific form of CD55, extensive third party literature has reported wild-type CD55 to play a role in cancer differentiation, migration and tissue invasiveness.  Patients with CD55+ expressing tumours are more likely to have a poor prognosis.