In October 2009, Patrys acquired the rights to PAT-SC1 from Debiovision Inc., a member of the global drug development Debiopharm Group.
PAT-SC1 was the first of the Patrys’ IgM antibodies to be used in a clinical trial conducted at the University of Würzburg Medical Centre in Germany. Between 1997 and 2001, 51 patients with CD55-positive gastric cancer were treated with a single intravenous low dose of PAT-SC1 48 hours prior to surgery. Of those 51 patients treated, 35 of them had no evidence of metastatic disease at operation and were classified as having R0 stage disease. Patients did not receive any additional treatment (radiotherapy or chemotherapy).
Survival of these patients has been followed over time and compared to a historic control group of patients with R0 stage gastric cancer who did not receive PAT-SC1 before surgery. Ten year follow-up data is now available on 30 of the PAT-SC1 treated patients. Fifty-five per cent of these patients are still alive whilst only 30% of the control group have survived, indicating that the treatment of gastric cancer patients with PAT-SC1 confers a significant survival benefit. There are no broadly effective treatments for gastric cancer, as evidenced by the fact that 80% of patients die within five years of diagnosis.
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.
In September 2015, Patrys completed a license agreement with Hefei Co-source Biomedical Co. LTD, a Chinese based company which is part of the Hefei Co-source Medicine Group focussed on integrated drug development. The deal covers the exclusive development and commercialisation rights for all oncology indications in China for PAT-SC1. Patrys will receive an upfront payment at that time and retains the right to develop and commercialise PAT-SC1 outside of China. Patrys continues to look for partners for this asset in other jurisdictions.
• F Hensel, W Timmermann, B Von Rahden, S Brändlein, A Rosenwald, B Illert. Ten year follow up of a prospective trial for the targeted therapy of gastric cancer with the human monoclonal antibody PAT-SC1, Oncology Reports, 2014, 31(3): 1059-66.
• Beutner U, Lorenz U, Illert B, Rott L, Timmermann W, Vollmers HP, Muller-Hermelink HK, Thiede A, and Ulrichs K. Neoadjuvant therapy of gastric cancer with the human monoclonal IgM antibody SC-1: Impact on the immune system, Oncol Rep. 19(3), 761-769 (2008).
• Illert B, Otto C, Vollmers HP, Hensel F, Thiede A,Timmermann W. Human antibody SC-1 reduces disseminated tumor cells in nude mice with human gastric cancer, Oncol Rep., 13(4),765-770 (2005).
• Hensel F, Herrmann R, Brändlein S, Krenn V, Schmausser B, Geis S, Müller-Hermelink HK, Vollmers HP. Regulation of the New Coexpressed CD55 (Decay Accelerating Factor) receptor on stomach carcinoma cells involved in antibody SC-1-induced apoptosis , Lab. Invest., 81(11), 1553-1563 (2001).
• Hermann R, Hensel F, Mueller E, Keppler M, Souto-Carneiro MM, Brändlein S, Müller-Hermelink HK, and Vollmers HP. Deactivation of regulatory proteins hnRNP A1 and A2 during SC-1 induced apoptosis, Hum. Antibodies, 10(2), 83-90 (2001).
• Hensel F, Hermann R, Schubert C, Abé N, Schmidt K, Franke A, Shevchenko A, Mann M, Müller-Hermelink HK, and Vollmers HP. Characterisation of glycosylphosphatidylinositol linked molecule CD55/Decay accelerating factor as the receptor for antibody SC-1-induced apoptosis, Cancer Res., 59(20), 5299-5306 (1999).
• Vollmers HP, Hensel F, Hermann R, Daemmrich J, Wozniak E, Gessner P, Herrmann B, Zimmermann U and Müller-Hermelink HK. Tumor-specific apoptosis by the human monoclonal antibody SC-1: A new therapeutical approach for stomach cancer, Oncol Rep., 5(1), 35-40 (1998).
• Vollmers HP, Zimmermann U, Krenn V, Timmermann W, Illert B, Hensel F, Hermann R, Thiede A, Wilhelm M, Rueckle-Lanz H, Reindl L and Mueller-Hermelink HK. Adjuvant therapy for gastric adenocarcinoma with the apoptosis-inducing human monoclonal antibody SC-1: first clinical and histopathological results, Oncol. Rep., 5(3), 549-552 (1998).