According to a new study published in the American Society of Hematology's journal Blood, researchers have found that frontline imatinib use for the treatment of chronic myeloid leukemia (CML) with selective switching to nilotinib resulted in high rates of overall survival, transformation-free survival, EMR, and MMR.
For the TIDEL-II study, researchers sought to investigate the use of upfront imatinib use in patients with CML with an early switch to nilotinib when patients fail to achieve time-dependent molecular targets. They enrolled 210 patients and assigned them to two sequential cohorts. Both cohorts started the study by receiving imatinib 600mg/day orally.
All patients were to be dose escalated to 800mg/day if their imatinib plasma trough level was 1000ng/mL on day 22. Patients were then assessed with molecular treatment targets: BCR-ABL1 ≤10% at 3 months, ≤1% at 6 months, and ≤0.1% at 12 months.
Patients in cohort 1 who failed to BCR-ABL1 targets were dose escalated to 800mg/day. If they failed the same molecular target 3 months later, they were switched to nilotinib 400mg orally twice daily.
Patients in cohort 2 were switched to nilotinib automatically if they failed to achieve targets. At 2 years, 55% of all patients were still on imatinib, while 30% had switched to nilotinib. At 3 years, the overall survival rate was 96% and the transformation-free survival was 95%. At 12 months, 64% had confirmed MMR and at 24 months, 73% had confirmed MMR.
TIDEL–II was designed to optimise outcomes for newly–diagnosed chronic phase chronic myeloid leukemia (CP–CML) patients. This trial supports the feasibility and efficacy of an imatinib–based approach with selective switching to nilotinib.