 Initial "in vivo" investigation on the antineoplastic activity showed positive result, but then only at high dosage and at high toxicity.At the same time in Germany, Hansjörg Eibl, at the Max Planck Institute for Biophysical Chemistry, and Clemens Unger, at the University of Göttingen, demonstrated that the antineoplastic activity of the phospholipid analogue miltefosine (at the time known as hexadecylphosphocholine) was indeed tumour-specific.It was highly effective against methylnitrosourea-induced mammary carcinoma, but less so on transplantable mammary carcinomas and autochthonous benzo(a)pyrene-induced sarcomas, and relatively inactive on Walker 256 carcinosarcoma and autochthonous acetoxymethylmethylnitrosamine-induced colonic tumors of rats.