Hi Alison,
As far as I understand it is uncommon that patients respond after three cycles of Vidaza - often up to six cycles are needed.
At the ASH conference 2007 they showed quite good results when they gave Vidaza 75 mg/kvm only 5 days instead of 7 days.
Here are some results: AZA 75 mg/m/day x 5 days. Number of patients = 49. Most pts are FAB classification RA/RARS (57%) or RAEB (30%). 67% achieved transfusion independence. 39% RBC increased , 18% platelets increased, 8% neutrophil increased.
Any haematological improvement 57% 
.
Kind regards
Birgitta-A
69 yo, dx MDS Interm-1 May 2006, transfusion dependent, Desferal 4 days with transfusion, Neupogen 2 injections/week, waiting for approval of Eltrombopag for my platelets so I dare start with Vidaza