m-AMSA: an exciting new drug in the National Cancer Institute Drug Development Program.

m-AMSA is a new drug in the National Cancer Institute Drug Development Program. The drug has moderate but tolerable toxicity and has demonstrated tumor activity in acute leukemia and breast cancer. Numerous phase II studies are completed or in progress and phase III trials will soon begin. We review the preclinical and phase I clinical information on this drug. We then enumerate the present ongoing studies and make some suggestions for future studies that will allow a rapid and orderly assessment of its value.