Protalix Reports Phase I Clinical Study Results for PRX-106 Showed Favorable Safety, Tolerability Profile Activity

Protalix BioTherapeutics, Inc. PLX announced today positive clinical study results from the Company's Phase I trial of PRX-106, an orally administered plant cell-expressed recombinant anti-TNF fusion protein. PRX-106 demonstrated a favorable safety and tolerability profile and biological activity in the gut. The Phase I trial is a randomized, parallel-design, open-label study designed to evaluate the safety and pharmacokinetics of PRX-106 in healthy volunteers. The trial enrolled 14 subjects that were randomized to one of three dosing cohorts receiving PRX-106 doses equivalent to 2mg, 8mg or 16mg Tumor Necrosis Factor receptor-Fc fusion protein. Subjects received once daily oral administrations for 5 consecutive days. The results demonstrated that oral administration of PRX-106 is safe and well tolerated. No major side effects were noted, and no suppression of the immune system was observed. Regulatory T cell activation showing biological activity in the gut was observed. Fluorescence-activated cell sorting analysis (FACS) was performed using various antibodies for surface markers, and it was observed that all three dosages of PRX-106 promoted the induction of various subsets of T cells, some of which are correlated with anti-inflammatory response. "The results demonstrated in the Phase I trial are very exciting and encouraging. As T regulatory cells have a central role in the immune system, PRX-106 has the potential to be an effective agent for numerous immune-mediated indications," said Prof. Yaron Ilan of the Gastroenterology and Liver Units, Director of the Department of Medicine of the Hebrew University-Hadassah Medical Center in Jerusalem. In preclinical studies evaluating oral PRX-106 the compound alleviated immune-mediated hepatitis and reduced interferon gamma levels in a concanavalin A immune mediated hepatitis mouse model. Additionally, oral administration of PRX-106 alleviated immune mediated colitis in a well-established mouse model, promoting serum levels of anti-inflammatory IL-10 and regulatory T-cells. Protalix is currently evaluating the best indication to take forward with PRX-106. The Company anticipates identifying this shortly and initiating a proof of concept trial in patients around year end.