AS1413 is a DNA intercalator that induces apoptotic signalling by blocking TopoII binding to DNA. Unlike classical TopoII inhibitors, a distinctive feature of AS1413 is its ability to evade PgP and related transporters responsible for multi-drug resistance. AS1413 is currently in phase III development in secondary AML.

Secondary AML (acute myeloid leukaemia)

AML is divided into two major categories, de-novo and secondary. AML is classified as secondary AML if it occurs as a result of a prior haematological disease or treatment with chemotherapy or radiation therapy or a combination of the two causes. In a phase II trial, treatment with AS1413 plus cytarabine resulted in a complete response rate of 38.6%, with an additional 3.4% showing CRi (complete response without recovery of blood cell count). This compares with CR rates of around 25% seen with standard treatment in similar AML patients enrolled in two large American studies. AS1413 is now in a phase III registration trial called ACCEDE. The ACCEDE trial compares AS1413 plus cytarabine with daunorubicin plus cytarabine in 450 patients.