Effectiveness of P-aminobenzoyl-O-phenylenediamine (Goe 1734) against mouse, rat, and human tumour cells.

The new N-phenylbenzamide derivative Goe 1734 was tested for its antitumour effects against mouse, rat, and human tumours. The preparation showed marginal activity against leukaemia L1210, moderate activity against Lewis lung carcinoma, and high activity against osteosarcoma C22LR and Brown Norway myeloid leukaemia. In the subrenal capsule assay the drug was active against four (cisplatin: 2) of nine human tumours. An in vitro clonogenic assay did not reveal any activity of Goe 1734 when mouse osteosarcoma or human tumour cells were exposed for only 1 h. However, continuous exposure led to 70% or greater inhibition of colony formation at concentrations of 0.1-1 microgram/ml (osteosarcoma) or 0.2-2 micrograms/ml (human tumours).