Melphalan: a potential new agent in the treatment of childhood rhabdomyosarcoma.

Melphalan has been evaluated against a series of seven childhood rhabdomyosarcomas, each derived from a different patient and maintained in vivo as xenografts in immune-deprived mice. Six lines were derived from untreated tumors and one from a patient refractory to conventional therapy. At the maximum tolerated dose (LD10) a single administration of melphalan caused complete regressions of advanced tumor in six of seven lines, including xenografts derived from the refractory patient. This agent demonstrated activity over a broad range of doses, and was considerably more active than vincristine, cyclophosphamide, doxorubicin, and dactinomycin in the model.