Peptichemio (PTC), a multipeptidic complex of m-L-phenyl-alanine mustard, was administered to 39 children with neuroblastoma at relapse. The compound was given in two 5-day cycles at dosages varying from 1.0-1.5 mg/kg/day. We were able to evaluate 29 of the initial 39 children for PTC effect; 21 of them had received PTC as first therapy following diagnosis. Ten patients underwent other chemotherapy for relapse before PTC. Three patients were off therapy when relapse occurred. Subjective improvement was observed in 18 cases (62%). Eleven patients (38%) experienced an objective regression, which was scored as complete response in three cases, partial response in two, mixed response in six. In ten children no significant disease change was observed; the remaining eight had a progression of their disease while receiving PTC. The incidence of responses has been higher in patients off therapy at moment of relapse, and lower in those pretreated for their relapse. Previous administration of PTC did not reduce the chance of response at relapse. Major toxic effects were transient, mostly moderate myelodepression and phlebosclerosis. Allergic reactions, nausea, and vomiting, occurred in a few patients. These data indicate that PTC may exert objective antitumor activity in approximately one-third of neuroblastoma patients at relapse.
