Enzyme inhibitor
This photosensitive pyridopyrimidine (FW = 330.19 g/mol), known systematically as 4-[(3-bromophenyl)amino]-6-(methylamino)pyrido[3,4- d]pyridimine, inhibits EPGFR (epidermal growth factor receptor) proteintyrosine kinase (IC50 = 8 pM). In addition, PD 158780 inhibits heregulinstimulated autophosphorylation in SK-BR-3 (IC50 = 49 nM) and MDA-MB- 453 (IC50 = 52 nM) breast carcinomas.