Immunotherapy with an intralesionally administered synthetic cord factor analogue

Injection of emulsified 6,6'-di-O-2-tetradecyl-3-hydroxyoctadecanoyl-a, a trehalose designated C76, a synthetic analogue of the mycobacterial glycolipid trehalose-6,6'-dimycolate (TDM), into transplants of an established, syngeneic murine fibrosarcoma induced complete regression of tumor in a number of animals. The number of animals in which tumor regressed completely dependent on the amount of oil in the emulsion. On a weight basis, C76 was at least as active as TDM. Intralesional injection of an emulsified mixture of C76 and endotoxin (ET) or of TDM and ET caused regression of an established transplant of a guinea-pig hepatoma in syngeneic animals. In mice, intravenously administered emulsions of C76 were less toxic and less granulomagenic than those made with TDM.