Antineoplastic activity and tolerability of a novel heterocyclic alkylphospholipid, D-20133

Octadecyl-[2-(N-methylpiperidinio)ethyl]-phosphate (OMPEP, D-20133), a heterocyclic analogue of hexadecylphosphocholine (MIL), has been synthesized in an attempt to increase the therapeutic range of the parent compound. The antineoplastic activity of the novel alkylphospholipid was compared with that of MIL in dimethylbenz(a)anthracene-induced mammary carcinoma of the rat. Using tumors of different sizes and repeated daily doses as well as high single doses, we achieved marked remissions with either compound. However, the therapeutic range of OMPEP was broader than that of the parent drug. Furthermore, the emetic potential of OMPEP tested on ferrets was distinctly less pronounced than that of MIL. In vitro the new alkylphospholipid proved to be more active than MIL in all cell lines tested, and its differentiation-inducing capacity turned out to be superior to that of MIL. No hematological toxicity was observed at various OMPEP doses during a 3-week treatment period.