Coley's toxins

Coley's toxins (also called Coley's toxin, Coley's vaccine, Coley vaccine, Coley's fluid or mixed bacterial vaccine) is a mixture containing toxins filtered from killed bacteria of species Streptococcus pyogenes and Serratia marcescens, named after William Coley, a surgical oncologist at the Hospital for Special Surgery who developed the mixture in the late 19th century as a treatment for cancer.

Their use in the late nineteenth and early 20th centuries represented a precursor to modern cancer immunotherapy, although at that time their mechanism of action was not completely understood.

There is no evidence that Coley's toxins have any effectiveness in treating cancer, and use of them risks causing serious harm.