Species of Clostridium bacteria have been shown to kill tumor cells growing under hypoxic conditions. In a study reported in Science Translational Medicine, Roberts and colleagues showed that intratumoral injection of an attenuated strain of Clostridium novyi (C novyi-NT) produced a microscopically precise tumor-localized response in a rat orthotopic brain tumor model.
In a study in naturally occurring canine solid tumors, intratumoral injection of the spores was well tolerated, with the most common toxicities being symptoms associated with bacterial infection. Objective response occurred in 6 (37.5%) of 16 dogs, including three complete responses. Intratumoral injection of C novyi-NT spores in a patient with advanced leiomyosarcoma resulted in tumor shrinkage within and surrounding the bone.
The investigators concluded: “Together, these results show that C novyi-NT can precisely eradicate neoplastic tissues and suggest that further clinical trials of this agent in selected patients are warranted.” ■
Roberts NJ, et al: Sci Transl Med 6:249ra111, 2014.