The results of the International Randomized Study of Interferon and STI571 (IRIS) trial
indicate that in patients with chronic phase CML treated with first line imatinib,
achievement of a complete or partial cytogenetic response (CCyR or PCyR) at 12 months is
associated with a significantly better progression-free survival (PFS).
Second generation tyrosine kinase inhibitors such as nilotinib can overcome imatinib
resistance because of greater potency to bind to BCR-ABL. Recent results indicate that, in
patients with previously untreated chronic phase CML, nilotinib results in a faster and
higher rate of CCyR or PCyR than imatinib. However, nilotinib use is associated with diet
restriction and much higher financial cost.
The primary objective of this study is to evaluate the ability of imatinib to maintain a
complete cytogenetic response (CcyR) in patients who achieved a CCyR after 12 months of
first-line treatment with nilotinib.