Nis-Theta

Nis-Theta is an engineered, probiotic-based bacterial therapy designed for the treatment of pancreatic ductal adenocarcinoma (PDAC). It utilizes a probiotic strain of *Escherichia coli*, Nissle 1917 (Nis), as a delivery vehicle for the pore-forming Theta toxin (perfringolysin O) derived from *Clostridium perfringens*. The therapy exploits the hypoxic and immunosuppressive microenvironment of PDAC tumors, where the bacteria can selectively colonize and provide a stable source of the cytotoxic toxin. Preclinical studies in mouse models have shown that Nis-Theta can induce complete tumor regression, reduce growth kinetics, and target metastatic lesions through bacterial translocation. The treatment has demonstrated safety in animal models, with minimal spread to healthy tissues and systemic clearance following tumor regression.

Other names

Nissle 1917-Theta toxinNissle1917-Theta toxinNissle-1917-Theta toxinengineered E. coli Nissle 1917 expressing Theta toxin