Antitumor activity of Corynebacterium parvum extracts.

Extracts of Corynebacterium parvum produced by mild hydrolysis of the whole organisms had antitumor activity if given iv 1 day before iv administration of fibrosarcoma cells or if given ip or sc in admixture with these cells. A lipid component seemed responsible for these effects. Unlike whole bacteria, they had little immunotherapeutic activity if given 3 days after sc tumor implantation unless absorbed onto latex. However, organisms treated with acid did not have any immunotherapeutic effect in this system either. The extracts, therefore, did have some antitumor activity, but full activity may depend on the integrity of the whole bacterium.