Hi Lucky,
Well you should be very pleased indeed. Your brother has responded extremely well to dasatinib (Sprycel) and from the figures you give above calculated on the IS, his disease has reduced by more than 3 logs from 100% at diagnosis.
Briefly it works like this:
LEVELS OF MOLECULAR RESPONSE from 100% at diagnosis using the Interational Scale (IS):
A Q-PCR test result shows the ratio of (abnormal) BCR/Abl to (normal)Abl of:
0.1% Bcr/Abl = MR 3 (3 log reduction from 100% at diagnosis)
0.01% Bcr/Abl = MR 4
0.0032% Bcr/Abl = MR 4.5
0.0001% Bcr/Abl = MR 5
What do such results mean for the individual? What is the prognostic value of 3 log or lower reduction from diagnosis?
It is now generally agreed that the lower the percentage (or the greater the log reduction) of of Bcr/Abl transcripts, the better the long term outlook, i.e the disease will not progress over the longer term and it is very likely that you will survive CML over your lifetime.
Recently published research shows that if you achieve MR3 or even lower in the first 3-6 months of TKi therapy the greater the chances that the disease will remain at low molecular levels and you will live out your normal lifespan- or at least you will not die from CML (as long as you remain >90% adherent to therapy)
I seems that 2G TKis (like dasatinib and nilotinib as well as others coming on stream) are very effective in helping patients achieve faster and deeper molecular responses.
I hope this answers your question and helps you -and your brother- celebrate his 'optimal' response to therapy.
Congratulations ;o)
Sandy
