http://www.medwirene...ng,_choice.html
"Second-line treatment following first-line toxicity can consist of any alternative TKI. Following resistance to imatinib, patients should switch to another TKI, such as dasatinib, nilotinib, bosutinib or ponatinib. From nilotinib, patients should switch to dasatinib, bosutinib or ponatinib, whereas patients with dasatinib resistance should be given nilotinib, bosutinib or ponatinib."
A goal of treatment is to lead to treatment free remission (TFR). TFR is a goal for second line TKI's for patients who achieve rapid and deep molecular remission.