Phase I study of cyclohexylamine and lysine salt of mafosfamide.

Mafosfamide is a new oxazaphosphorine that breaks down spontaneously into 4-hydroxy-cyclophosphamide. A phase I trial with cyclohexylamine and lysine salts of mafosfamide was carried out in 16 patients, using weekly IV perfusion. Dose-limiting toxicities were not hematological, but consisted in the development of severe pain along the vein during administration. A particular mucosal syndrome with sneezing and conjunctivitis was seen only after administration of the lysine salt. The dose of 700 mg/m2 per week represents the maximum tolerated dose with this weekly schedule.