LIPOSOME-ENCAPSULATED MURAMYL TRIPEPTIDE PHOSPHATIDYL-ETHANOLAMINE (L-MTP-PE) - A RANDOMIZED CLINICAL-TRIAL IN DOGS WITH MAMMARY-CARCINOMA

In this prospective randomized double-blind clinical study the anti-tu mour activity of liposome-encapsulated muramyl tripeptide phosphatidyl ethanolamine (L-MTP-PE) was evaluated as an adjuvant immunotherapy in dogs with mammary tumours of the simple carcinoma type. Dogs were rand omized after surgery to one of two treatment groups, in which they wer e treated with either L-MTP-PE (2 mg/m(2) i.v.; Ciba Geigy Basel, Swit zerland) twice weekly for eight weeks, or with empty liposomes accordi ng to the same protocol. The minimal follow-up period was one year Thi rteen dogs were entered in the L-MTP-PE group and four teen dogs in th e placebo control group. Only minor toxicities (fever and shivering du ring 10-24 hours) were seen in six dogs treated with L-MTP-PE, these b eing mainly of the smaller breeds. At the time of evaluation seven dog s were still disease free. In the other twenty dogs the disease-free p eriod (DFP) was ended by local recurrences in 16 and by distant metast ases in 4 The difference in DFP between dogs treated with L-MTP-PE (me dian 165 days, range 15-905) and dogs in the placebo group (median 133 days, range 27-659) was not significant The difference in overall sur vival between the dogs treated with L-MTP-PE (median 222 days range 36 -905) and those receiving the placebo (median 182 days, range 54-659) was also not significant It was concluded that liposome-encapsulated M TP-PE was not efficacious in the treatment of dogs with mammary carcmo ma.