Pharmacologic and toxicologic evaluation of C. novyi-NT spores

Toxicol Sci. 2005 Dec;88(2):562-75. doi: 10.1093/toxsci/kfi316. Epub 2005 Sep 14.


Clostridium novyi-NT (C. novyi-NT) spores have been shown to be potent therapeutic agents in experimental tumors of mice and rabbits. In the present study, pharmacologic and toxicologic studies were performed to better understand the factors influencing the efficacy and toxicity of this form of therapy. We found that spores were rapidly cleared from the circulation by the reticuloendothelial system. Even after large doses were administered, no clinical toxicity was observed in healthy mice or rabbits. The spores were also not toxic in mice harboring poorly vascularized non-neoplastic lesions, including myocardial infarcts. In tumor-bearing mice, toxicity appeared related to tumor size and spore dose, as expected with any bacterial infection. However, there was no laboratory or histopathologic evidence of sepsis, and the toxicity could be effectively controlled by simple hydration.

Publication types

  • Multicenter Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antineoplastic Agents, Phytogenic / pharmacokinetics
  • Antineoplastic Agents, Phytogenic / toxicity*
  • Bacterial Toxins / pharmacokinetics
  • Bacterial Toxins / toxicity*
  • Cell Line
  • Clostridium / growth & development
  • Clostridium / pathogenicity*
  • Disease Models, Animal
  • Female
  • Injections, Intravenous
  • Longevity / drug effects
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Mice, Inbred C57BL
  • Mice, Nude
  • Neoplasms, Experimental / mortality
  • Neoplasms, Experimental / pathology
  • Neoplasms, Experimental / therapy*
  • Rabbits
  • Spores, Bacterial / pathogenicity*
  • Survival Rate


  • Antineoplastic Agents, Phytogenic
  • Bacterial Toxins