Biotech Values

[biomaven0]

seems as though this field has not evolved that much during the past eight years

Well it has evolved some, but it's inherently difficult. There's no one assay that reliably identifies all CSCs - for example the assay used in the PNAS paper relies on cells expressing the enzyme aldehyde dehydrogenase. But not all CSCs appear to express ALDH, and some normal stem cells express it too. Other assays look at cell surface markers, but there is no agreed set of these either.

So basically they are hard to find and hard to kill. CSC's are inherently rugged - they don't divide quickly and so most chemo drugs are useless, and they seem to be generally hardier than regular cells. (Presumably from an evolutionary perspective the body views regular cells as disposable, but stem cells as non-disposable).

From a biotech investing standpoint, companies perceive it to be desirable to say their product targets CSCs. But it's very hard for an outsider to judge if they actually do so or not, so caution is appropriate.

Peter