Hi Thomas
I wouldn't rush too quickly to try to understand everything - that will take time. There are lots of subtleties in all these targets and data, which can confuse the picture somewhat.
Basically, the deeper the response the better but experience is that achieving the deepest response isn't necessary for the key outcome, which is to avoid progression from chronic phase to accelerated phase or blast crisis. Most patients go along quite happily with less deep responses than CMR and even MMR and never progress.
What the second set of information you note is telling you, at least the bit you pick out, is that if you achieve major molecular response - a very deep response - by 12-18 months your chances of progression after 7 years appear to be nil. So, that's what to aim for.
CMR (which used to be complete molecular response and is now MMR 4.5 - refers to the log reduction in BCR/ABL) is a very deep response - deeper than MMR. A minority of people get to that point. The fact that 30% of that minority of patients may lose CMR (though it doesn't tell you how many get it back again) doesn't really matter since it is MMR that is thought to be the safe haven (though if you get a deep response short of MMR that doesn't mean chances of progression are necessarily meaningfully higher). There aren't figures to show how many patients who lose CMR also lose MMR - perhaps the key thing here. Very few I imagine.
So - there are I think three responses to look to achieve, all are good.
Complete cytogenic response - good
Major Molecular response - excellent. Safe haven probably.
CMR - best but not necessary.
CMR is relevant for the possibility to stop treatment, which I think is the focus of the group responsible for the first study you mention.
Sandy will correct my errors and add things I've missed I am sure.
Richard
