Hi Greg,
Yes, Vidaza was initially used in very high doses that gave severe nausea.
Epigenetic drugs like Vidaza
Here dr List tries to explain how hypermethylation (too many methyl groups) leads to tumor suppressing gene silencing.
http://assets.aamds.org/pdfs/ListHighRisk.pdf
Chemo like Cytarabine
“Cytarabine belongs to the category of chemotherapy called antimetabolites. Antimetabolites are very similar to normal substances within the cell. When the cells incorporate these substances into the cellular metabolism, they are unable to divide.” http://www.chemocare.com/bio/cytarabine_liposomal.asp
As far as I understand you are right when you write that chemo reduces the population of cancer cells and epigenetic drugs change the way the cancer cells are working. Sooner or later both types of drugs stop working and we have to try something else.
Kind regards
Birgitta-A