Cancer stem cell biology is a hot new area of cancer (and stem cell) research since the first cancer stem cells (tumor cells with stem cell like properties) were identified in the early 1990s. It’s thought that this subset of tumor cells drives tumor growth and resists treatment, causing the tumor to come back.

I’ve heard biologists in Boston talk about how new the science of cancer stem cells is (and there are plenty of unanswered questions, as seen here) so I was a bit surprised (though I really shouldn’t be) to hear this morning that two US biotech companies, Oncomed Pharmaceuticals and Stemline Therapeutics, are nevertheless forging ahead with the development of drugs that target receptors on the surface of cancer stem cells, in solid tumors and hematologic cancers. The hope is that going after these cells will kill the tumor once and for all.

Oncomed says it hopes to have its lead monoclonal antibodies in clinical trials by 2008. Stemline says its drug has already been tested in 25 people with leukemia in phase I clinical trials and they plan on expanding that trial. So like many biotech companies, these two aren’t waiting for all the science to be in before diving into drug development.