TIDEL-II: first-line use of imatinib in CML with early switch to nilotinib for failure to achieve time-dependent...

Area of Science:

• Hematology
• Oncology
• Pharmacology

Background:

• Chronic myeloid leukemia (CML) requires effective initial treatment strategies.
• Optimizing molecular response in de novo CML is crucial for long-term outcomes.
• The TIDEL-II study investigated an intensified treatment approach for newly diagnosed CML.

Purpose of the Study:

• To evaluate the efficacy of an imatinib-based treatment strategy with early, selective switching to nilotinib in de novo CML.
• To assess molecular response rates, overall survival, and transformation-free survival.
• To determine the feasibility of intensifying imatinib treatment based on plasma trough levels and molecular response.

Main Methods:

• The TIDEL-II study enrolled 210 de novo CML patients in two cohorts.
• Patients initiated imatinib 600 mg/day, with dose escalation to 800 mg/day if plasma trough levels were <1000 ng/mL at day 22.
• Treatment adjustments (escalation to imatinib or switch to nilotinib) were based on predefined BCR-ABL1 molecular targets at 3, 6, and 12 months.

Main Results:

• At 2 years, 55% of patients remained on imatinib and 30% on nilotinib.
• Only 12% of patients had BCR-ABL1 >10% at 3 months.
• Confirmed major molecular response was achieved in 73% at 24 months, with 34% achieving MR4.5.
• Three-year overall survival was 96%, and transformation-free survival was 95%.

Conclusions:

• An imatinib-based treatment strategy with selective, early switching to nilotinib is feasible and effective for de novo CML.
• This approach leads to high rates of molecular response and favorable long-term survival.
• Treatment intensification based on early monitoring of imatinib levels and molecular response is a viable strategy for CML management.