Liposome-encapsulated muramyl tripeptide phosphatidylethanolamine for the treatment of feline mammary adenocarcinoma--a multicenter randomized double-blind study.

Forty cats with previously untreated, histologically confirmed mammary gland adenocarcinoma received a radical mastectomy of the affected mammary chain(s). All cats were stratified according to clinical stage and randomized to receive either weekly intravenous liposome-encapsulated muramyl tripeptide phosphatidylethanolamine or placebo (lipid-equivalent) for eight consecutive weeks in this double-blind study. Thirty-six of the 40 cats were available for follow-up. No significant differences in either disease-free interval or survival were found as a result of treatment. Cats with clinical stage II disease had a statistically significantly longer disease-free interval (p < 0.02), and overall survival (p < 0.005) when compared with clinical stage III cats.