Pyrrolo[1,2-b][1,2,5]benzothiadiazepines (PBTDs): A new class of agents with high apoptotic activity in chronic myelogenous leukemia K562 cells and in cells from patients at onset and who were imatinib-resistant.

Pyrrolo[1,2-b][1,2,5]benzothiadiazepine 5,5-dioxides (PBTDs) induced apoptosis in human BCR-ABL-expressing leukemia cells. The apoptotic activity was also observed in primary leukemic blasts, obtained from chronic myelogenous leukemia (CML) patients at onset or from patients in blast crisis and who were imatinib-resistant. Compounds 5 and 14 induced apoptosis before BCR-ABL protein expression and tyrosin phosphorylation were affected and activated different caspases in the apoptotic pathway. PBTDs are a new class of valid candidates for the treatment of CML.